U.S. patent application number 15/968545 was filed with the patent office on 2018-08-30 for method for treating intestinal fibrosis.
This patent application is currently assigned to Sigmoid Pharma Limited. The applicant listed for this patent is Sigmoid Pharma Limited. Invention is credited to Vincenzo Aversa, Ivan Coulter.
Application Number | 20180243210 15/968545 |
Document ID | / |
Family ID | 48226371 |
Filed Date | 2018-08-30 |
United States Patent
Application |
20180243210 |
Kind Code |
A1 |
Coulter; Ivan ; et
al. |
August 30, 2018 |
METHOD FOR TREATING INTESTINAL FIBROSIS
Abstract
A method for treating intestinal fibrosis in a subject,
comprising enterally administering a steroid to the subject. The
steroid may be in a multiple minibead formulation.
Inventors: |
Coulter; Ivan; (Dublin,
IE) ; Aversa; Vincenzo; (Dublin, IE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Sigmoid Pharma Limited |
Dublin |
|
IE |
|
|
Assignee: |
Sigmoid Pharma Limited
Dublin
IE
|
Family ID: |
48226371 |
Appl. No.: |
15/968545 |
Filed: |
May 1, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15090377 |
Apr 4, 2016 |
9980902 |
|
|
15968545 |
|
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|
|
14185786 |
Feb 20, 2014 |
9320746 |
|
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15090377 |
|
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61767632 |
Feb 21, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 9/4808 20130101;
A61K 9/1611 20130101; A61K 31/502 20130101; A61K 9/1641 20130101;
A61K 9/0053 20130101; A61P 1/00 20180101; A61K 9/16 20130101; A61P
1/04 20180101; A61K 38/13 20130101; A61K 31/223 20130101; A61K
31/58 20130101; A61K 9/1623 20130101; A61K 9/1658 20130101; A61K
9/50 20130101; A61K 9/5036 20130101; A61K 9/1694 20130101; A61K
9/5042 20130101; A61K 31/56 20130101; A61K 9/1652 20130101; A61K
9/1617 20130101; A61P 43/00 20180101; A61K 9/4891 20130101; A61K
31/56 20130101; A61K 2300/00 20130101; A61K 31/223 20130101; A61K
2300/00 20130101; A61K 31/502 20130101; A61K 2300/00 20130101; A61K
38/13 20130101; A61K 2300/00 20130101 |
International
Class: |
A61K 9/00 20060101
A61K009/00; A61K 9/16 20060101 A61K009/16; A61K 38/13 20060101
A61K038/13; A61K 31/58 20060101 A61K031/58; A61K 31/56 20060101
A61K031/56; A61K 31/502 20060101 A61K031/502; A61K 31/223 20060101
A61K031/223; A61K 9/50 20060101 A61K009/50; A61K 9/48 20060101
A61K009/48 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 14, 2013 |
GB |
1304662.8 |
Claims
1. An oral steroid formulation, the formulation being a multiple
minibead formulation wherein the minibeads comprise a water-soluble
polymer matrix in which a steroid is distributed, wherein the
steroid is distributed in the polymer matrix in any of the
following forms: a) as a solution in the polymer matrix; b)
dissolved in a disperse phase; c) as particles dispersed in a
disperse phase; d) dissolved in the aqueous phase of a water-in-oil
or water-in-wax emulsion dispersed in the polymer matrix.
2. The formulation according to claim 1, wherein the steroid is a
steroid susceptible to first pass metabolism.
3. The formulation according to claim 2, wherein the steroid
susceptible to first pass metabolism is selected from budesonide,
flunisolide, fluticasone proprionate, rimexolone, butixocort,
tixocortol and beclomethasone and the salts and esters,
thereof.
4. The formulation according to claim 2 wherein the steroid is
budesonide, or an ester thereof.
5. The formulation according to claim 1, wherein the steroid is
dissolved in a disperse phase.
6. The formulation according to claim 1, wherein the composition
comprises a dispersed phase distributed within the matrix.
7. The formulation according to claim 6, wherein the dispersed
phase comprises an oil.
8. The formulation according to claim 5, wherein the dispersed
phase comprises olive oil, sesame oil, coconut oil, palm kernel
oil, medium chain triglycerides, linoleoyl macrogolglycerides
(polyoxylglycerides), caprylocaproyl macrogolglycerides and
caprylic/capric triglycerides, 2-(2-ethoxyethoxy)ethanol,
poly(ethylene glycol) or a combination thereof.
9. The formulation according to claim 5, wherein the dispersed
phase comprises at least one surfactant.
10. The formulation according to claim 5, wherein the disperse
phase comprises a liquid or a wax which has a melting temperature
of no more than 37.degree. C.
11. The formulation according to claim 10, wherein the liquid or
wax comprises a macrogol ester.
12. The formulation according to claim 11, wherein the macrogol
ester is selected from macrogol 25 cetostearyl ether, macrogol 6
cetostearyl ether, macrogol glycerol ricinoleate 35,
macrogol-glycerol hydroxystearate 40 or
macrogol-15-hydroxystearate.
13. The formulation according to claim 12, wherein the macrogol
ester is macrogol-15-hydroxystearate.
14. The formulation according to claim 5, wherein the disperse
phase comprises a liquid or a wax which is solid or semi-solid at
ambient temperature.
15. The formulation according to claim 14, wherein the liquid or
wax comprises a macrogol ester.
16. The formulation according to claim 15, wherein the macrogol
ester is selected from macrogol 25 cetostearyl ether, macrogol 6
cetostearyl ether, macrogol glycerol ricinoleate 35,
macrogol-glycerol hydroxystearate 40 or
macrogol-15-hydroxystearate.
17. The formulation according to claim 16, wherein the macrogol
ester is macrogol-15-hydroxystearate
18. The formulation according to claim 10 wherein the liquid or wax
comprises a medium chain triglyceride.
19. The formulation according to claim 1, which is adapted to
release: the steroid at least in the colon; or the steroid at least
in the ileum; or the steroid at least in the jejunum; or the
steroid at least in the duodenum.
20. The formulation according to claim 1, which is an immediate
release formulation.
21. The formulation according to claim 1, which is a controlled
release formulation, the steroid being in solution in the
formulation.
22. The formulation according to claim 1, wherein the minibeads
comprise a coating.
23. The formulation according to claim 22, wherein the coating is a
controlled release coating.
24. The formulation according to claim 22, wherein the coating is
adapted to release the steroid in the colon.
25. The formulation according to claim 22, wherein the coating
comprises a polymeric material.
26. The formulation according to claim 25, wherein the polymeric
material comprises methacrylic acid co-polymers, ammonio
methacrylate co-polymers, polysaccharides, ethylcellulose,
methacrylic acid, methyl acrylate, methyl methacrylate,
hydroxypropyl methylcellulose, cellulose acetate phthalate,
cellulose acetate succinate, cellulose hydrogen phthalate,
cellulose acetate trimellitate, hydroxypropyl-methylcellulose
phthalate, hydroxypropyl methylcellulose acetate succinate, starch
acetate phthalate, amylose acetate phthalate, polyvinyl acetate
phthalate, polyvinyl butyrate phthalate or a combination
thereof.
27. The formulation according to claim 1, wherein the minibeads are
seamless minibeads that comprise the water-soluble polymer matrix
and, dispersed in the matrix, a disperse phase comprising materials
selected from hydrophobic and amphiphilic materials, and
combinations thereof, the steroid being included in the dispersed
phase.
28. The formulation according to claim 1, wherein the polymer
comprises or consists of gelatin or another thermotropic
hydrogel-forming polymer, or a combination thereof.
29. The formulation according to claim 1, wherein the composition
further comprises one, two or three of active agents (a), (b) and
(c) below: (a) an immunosuppressant; (b) a promoter of the
expression or activity of hypoxia-inducible factor; (c) another
anti-fibrotic agent.
30. The formulation according to claim 28, wherein the composition
comprises a promoter of the expression or activity of
hypoxia-inducible factor selected from hydroxylase inhibitors.
31. The formulation according to claim 1, wherein the formulation
further comprises at least one of the following active agent(s),
cyclosporin A, DMOG, hydralazine, FG-4497, FG4095, AGN-2979,
metirosine, 3-iodotyrosine, aquayamycin, bulbocapnine, oudenone, TM
6008, TM 6089, siRNAs against hydroxylases, antisense therapeutics
against hydroxylases, caspase inhibitors, peroxisome
proliferator-activated receptor-g (PPAR-g) agonists, pioglitazone,
TGF-b blockers, colchicines, relaxin, adiponectin, endothelin A,
angiotensin receptor blockers, cannabinoids, agents altering the
MMP-TIMP balance, a wound healing agent, Ilodecakin and
Mannose-6-Phosphate.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 15/090,377, filed Apr. 4, 2016, which claims the benefit of
U.S. application Ser. No. 14/185,786, filed Feb. 20, 2014, now U.S.
Pat. No. 9,320,746, issued Apr. 26, 2016, which claims the benefit
of U.S. Provisional Application No. 61/767,632, filed Feb. 21,
2013, and Great Britain Application No. 1304662.8, filed Mar. 14,
2013, all of which are incorporated herein by reference in their
entirety.
FIELD
[0002] This invention relates to pharmaceutical compositions useful
for medical purposes relating to fibrosis of the gastrointestinal
tract. The invention also relates to methods of making the
compositions, methods of using them, and other subject matter.
BACKGROUND
[0003] Tissue in a living creature is continually repairing and
regenerating. Normally this repair and regeneration occurs
naturally without any adverse effect. However, in certain
circumstances, for example following severe tissue damage or
inflammation, the repair and regeneration of the tissue can become
excessive, leading to fibrosis. Fibrosis is the presence of
excessive connective tissue and can generically be referred to as
scarring.
[0004] Within the gastrointestinal tract (GIT), fibrosis can be
caused by various diseases especially inflammatory- or
ischemic-induced diseases, for example cystic fibrosis,
inflammatory bowel diseases, Crohn's disease, ulcerative colitis,
coeliac diseases, proctitis, gastrointestinal graft-versus-host
disease (GIGVHD), ischemic bowel diseases, necrotizing
enterocolitis, and irritable bowel syndrome.
[0005] Patients suffering from these chronic conditions often have
the added complication of intestinal fibrosis. Fibrosis causes
strictures and obstruction of the intestine that require surgery to
remove along with portions of the bowel. The therapeutic problems
caused by bowel wall fibrosis are common: for example, about 75% of
all patients with Crohn's disease have to undergo surgery at least
once during the course of their disease. Such fibrosis is a long
term complication in inflammatory bowel disease in general,
including where therapies control the symptoms but the underlying
disease continues to be active and leads to tissue damage in the
form of fibrosis.
[0006] In contrast to anti-inflammatory treatment, little
therapeutic progress has been made with respect to intestinal
fibrosis. Current preventive attempts therefore rest primarily on
long-term anti-inflammatory treatment. However, this mainly
anti-inflammatory approach is often ineffective, leading to surgery
and stricturoplasty, which remain the major treatment methods for
intestinal fibrosis and, despite the major therapeutic advances in
the treatment of Crohn's disease, the incidence of stricture
formation in Crohn's disease has not markedly changed. Such
observations imply that control of inflammation at the clinical
level does not equate with control of fibrogenesis. Unfortunately,
even the surgical approach is often only associated with short-term
resolution of symptoms, as strictures tend to recur. For further
information on intestinal fibrosis see "Wound Healing and Fibrosis
in Intestinal Disease", F Rieder et al., Gut 2007; 56: 130-139 and
"Intestinal fibrosis in IBD--a dynamic, multifactorial process", F
Rieder et al., Nat. Rev. Gastroenterol. Hepatol. 6, 228-235
(2009).
[0007] There are, therefore, currently no satisfactory treatments
for intestinal fibrosis. At present, the only option other than
surgery to treat the obstructions and strictures caused by fibrosis
is endoscopic balloon dilation.
[0008] WO 2012/069658 discloses a method of administering to a
warm-blooded animal a formulation to treat, or delay the
progression of, a fibrotic intestinal disorder, or of maintenance
therapy of an animal which has suffered from or is suffering from a
fibrotic intestinal disorder, which method comprises orally
administering to the animal simultaneously, sequentially or
separately an immunosuppressant and a hydroxylase inhibitor. The
actives may be in a pharmaceutical composition which comprises a
hydrophobic phase in which the immunosuppressant is dissolved. For
example, the composition may be a multiple minibead composition
wherein the immunosuppressant and the hydroxylase inhibitor are
contained in the minibeads, each minibead comprising a
water-soluble polymer matrix material and, dispersed within the
matrix material, the hydrophobic phase. In an embodiment, the
immunosuppressant is cyclosporin A and the hydroxylase inhibitor is
hydralazine, in which case the hydralazine may be comprised in the
matrix material of such minibeads.
[0009] Budesonide (16, 17-butylidendioxy-11.beta.,
21-dihydroxy-1,4-pregnadien-3,20-dione) is a topical corticosteroid
characterized by potent local anti-inflammatory activity, and was
initially introduced for the treatment of asthma and rhinitis. Due
to an extensive first-pass elimination its systemic bioavailability
is only 10-15% compared with other corticosteroid formulations,
thus, improved safety and tolerability might be anticipated
(Navarro F et al., Treatment of inflammatory bowel disease: safety
and tolerability issues. Am J Gastroenterol 2003; 98 (12(Suppl):
S18-23).
[0010] Orally administered budesonide (sold as Entocort.RTM.) is
indicated for the treatment and maintenance therapy of Crohn's
disease involving the ileum and/or the ascending colon. It is
proposed also to use a budesonide formulation for the treatment of
ulcerative colitis (G R D'Haens et al., J Crohn's Colitis (2010) 4,
153-160). Such uses of budesonide are based on the compound's
anti-inflammatory activity and the compound is not indicated for
the treatment of intestinal fibrosis.
[0011] A new extended release budesonide formulation, namely
MMX.RTM.-budesonide tablets, has been made which is designed to
release budesonide at a controlled rate throughout the whole colon
for the oral treatment of inflammatory bowel diseases (IBD). See
Brunner M et al., Br J Clin Pharmacol 61:1, 31-38.
[0012] All of the above-mentioned publications, and all other
publications mentioned in this specification, are incorporated
herein by reference.
SUMMARY
[0013] This specification contains data indicating that steroid
formulations are efficacious in the treatment of intestinal
fibrosis. See Examples 12 and 17. The present invention provides a
steroid for use in the treatment of intestinal fibrosis. The
steroid may be for enteral administration, for example oral
administration. The present invention also provides a method of
treating intestinal fibrosis comprising administering a steroid to
a subject; the route of administration may be enteral, for example
oral.
[0014] For all aspects and implementations of the invention, the
therapy may affect the entirety of the GIT or a portion thereof. In
particular, the therapy may affect one or more regions of the
intestines. The entirety of the GIT may therefore be exposed to the
steroid. Alternatively, one or more portions of the GIT may be
exposed to the steroid, for example the small intestine and/or the
large intestine. Particularly, the GIT below the small intestine
may be exposed to the steroid, with or without exposure of all or a
part of the small intestine to the steroid. In instances where the
small intestine is exposed to the steroid, the ileum may be exposed
to the steroid, optionally together with one or more other regions
of the small intestine. The following region or regions of the GIT
may be exposed to the steroid, optionally together with one or more
other regions of the GIT: the ileum, or the colon, or the ileum and
the colon. The steroid may therefore be comprised in a controlled
release formulation adapted to release the steroid to all of the
GIT or to one or more portions of the GIT as mentioned in this
paragraph or elsewhere in this specification. It is generally
understood that the GIT below the small intestine comprises the
large intestine which, according to the Terminologia Anatomica
(TA), the international standard on human anatomic terminology,
comprises the cecum, colon, rectum and anal canal.
[0015] Delivery of the steroid to the GIT below the small intestine
means that the steroid is released into the lumen of the GIT below
the small intestine, and preferably into the colon.
[0016] As mentioned, the steroid may be administered enterally. It
may be delivered orally. It may be administered rectally.
Therefore, there is provided an enteral, e.g. oral or rectal,
steroid formulation for use in the treatment of intestinal
fibrosis. In one example, the enteral steroid formulation comprises
minibeads (sometimes called minicapsules or minispheres) and the
minicapsules comprise the steroid. In general, the formulation,
especially when an oral formulation, may be a multiple mini-format
formulation comprising a multiplicity of mini-format units, e.g.
pellets, minibeads, mini-tablets, mini-capsules etc. A mini-format
unit may have a largest cross-sectional dimension of 0.5 mm to 5
mm, e.g. 1 mm to 3 mm as in the case of 1 mm to 2 mm.
[0017] The formulation may be an immediate release formulation. The
formulation may be a controlled release formulation. The
formulation may comprise the steroid dissolved or dispersed in a
liquid, semi-solid or a solid. In particular, the formulation may
comprise the steroid dissolved in a liquid, semi-solid or a solid.
The formulation may therefore comprise a liquid, semi-solid or a
solid which is a solution containing the steroid. The steroid may
be dissolved or dispersed in a liquid or in a wax which has a
melting temperature of no more than 37.degree. C.; in particular,
the steroid may be dissolved in such a material which may,
therefore, be in the form of a solution containing the steroid.
[0018] The steroid may be dissolved or dispersed in a medium which
comprises or is a macrogol ester. The steroid may be dissolved in
such a medium. The medium may be a liquid or a wax, in particular a
wax which has a melting point of no more than 37.degree. C. In any
medium which comprises or is a macrogol ester, the macrogol ester
may be, or may comprise, macrogol-15-hydroxystearate.
[0019] The steroid may be dissolved or dispersed in a medium which
comprises or is a medium chain triglyceride. The steroid may be
dissolved in such a medium. The medium may comprise a medium chain
triglyceride and a surfactant, for example an anionic surfactant
and/or a non-ionic surfactant.
[0020] The steroid may therefore be comprised in an immediate
release formulation or in a controlled release formulation. The
steroid may be in solution in a formulation, for example a
controlled release formulation. In another example, the steroid is
in solution in an immediate release formulation.
[0021] The steroid may be comprised in an oral formulation adapted
to release the steroid at least in the duodenum. The steroid may be
comprised in an oral formulation adapted to release the steroid at
least in the jejenum. The steroid may be comprised in an oral
formulation adapted to release the steroid at least in the ileum.
The steroid may be comprised in an oral formulation adapted to
release the steroid at least in the cecum. The steroid may be
comprised in an oral formulation adapted to release the steroid at
least in the colon. The steroid may be comprised in an oral
formulation adapted to release the steroid at least in the small
intestine. The steroid may be comprised in an oral formulation
adapted to release the steroid at least in the large intestine. The
steroid may be comprised in an oral formulation adapted to release
the steroid in the small intestine and in the colon. The steroid
may be comprised in an oral formulation adapted to release the
steroid at least in the ileum and colon. The steroid may be
comprised in an oral formulation adapted to release the steroid at
least in the duodenum and the colon. The steroid may be comprised
in an oral formulation adapted to release the steroid at least in
the duodenum, the ileum and the colon. Where a formulation is
adapted to release the steroid "at least" in a specified GI region
or regions, the formulation may be adapted to release at least 50%
of the steroid in the specified region or regions.
[0022] The formulation may be adapted to prevent release of the
steroid in the stomach and optionally to prevent release in the
duodenum, and the jejenum; it may additionally be adapted to
prevent release of the steroid in the ileum. The formulation may be
adapted to release the steroid exclusively in the colon or in the
colon and at least one other region of the intestine, for example
in the ileum and colon or in the ileum, in the colon and in at
least one other intestinal region. The adaptation may comprise a
barrier, for example a coating. The coating may consist of a single
layer or plural layers.
[0023] The formulation may be a multiple minibead formulation. The
minibeads may comprise a water soluble polymer matrix in which the
steroid is distributed. The steroid may be distributed in the
polymer matrix in any of the following forms: [0024] 1) as a
solution in the polymer matrix (i.e. the steroid is dissolved in
the polymer matrix); [0025] 2) as a solid dispersion in the polymer
matrix, for example as nanoparticles or micropatricles; [0026] 3)
dissolved in a disperse phase, for example a hydrophobic phase or a
surfactant phase (i.e. the disperse phase may be a solution);
[0027] 4) as particles dispersed in a disperse phase, for example a
hydrophobic phase or a surfactant phase; [0028] 5) dissolved in the
aqueous phase of a water-in-oil or water-in-wax emulsion dispersed
in the polymer matrix.
[0029] The disperse phase may be a solid, a semi-solid or a liquid.
The hydrophobic phase may be an oil or a wax; it may comprise a
medium chain triglyceride, optionally in combination with at least
one surfactant, e.g. selected from anionic and non-ionic
surfactants. The surfactant phase may comprise, or be, a macrogol
ester. The macrogol ester may be macrogol-15-hydroxystearate.
[0030] The steroid may be comprised in a formulation, for example a
controlled release formulation, obtainable by a process comprising:
[0031] (i) dissolving a water-soluble polymer in water to form an
aqueous solution; [0032] (ii) dissolving or dispersing the steroid
in a liquid which will mix with the water to form a colloid to form
a steroid solution or dispersion (particularly a solution); [0033]
(iii) mixing the aqueous solution and the steroid solution or
dispersion to form a colloid; [0034] (iv) ejecting the colloid
through a nozzle to form droplets; and [0035] (v) causing or
allowing the water-soluble polymer to gel or form a solid.
[0036] The method may further include drying the solid. The water
may be comprised in an aqueous liquid, e.g. solution, containing
constituents other than water. There may therefore be used water as
such or another aqueous liquid.
[0037] The steroid may be comprised in a formulation, for example a
controlled release formulation, obtainable by a process comprising:
[0038] (a) dissolving in water a water-soluble polymer and
dissolving or dispersing in the water a steroid to form a solution
or dispersion and particularly a solution (the polymer may be mixed
with the water before the steroid or vice-versa, or the two may be
mixed with the water at the same time); [0039] (b) ejecting the
solution or dispersion through a nozzle to form droplets; and
[0040] (c) causing or allowing the water-soluble polymer to gel or
form a solid, the process optionally further comprising between
steps (a) and (b) a step (a1): [0041] (a1) mixing the solution or
dispersion and a liquid which will mix with water to form a
colloid, thereby to form a colloid.
[0042] The method may further include drying the solid. The water
may be comprised in an aqueous liquid, e.g. solution, containing
constituents other than water. There may therefore be used water as
such or another aqueous liquid.
[0043] The formulation obtainable as described in the two preceding
paragraphs may be an immediate release formulation instead of a
controlled release formulation.
[0044] The formulation may comprise an administrable unit
comprising multiple minibeads. The administrable unit may be a
capsule, in the case of oral administration, or a suppository, in
the case of rectal administration. In the case of controlled
release multiple minibead formulations, either the minibeads and/or
a unit comprising multiple minibeads (e.g. a capsule) may be
adapted to control release of the active. The formulations may
therefore comprise a barrier, for example a coating, as an element
of the minibeads and/or as an element of a capsule or other unit
comprising multiple minibeads. In the case of multiple minibead
formulations, it may be advantageous for the minibeads themselves
to be adapted for controlled release, optionally to the exclusion
of any unit comprising them.
[0045] In the case of multiple minibead formulations, at least some
of the minibeads, e.g. all of them, may be adapted to prevent
release of the steroid in at least the stomach. For example the
minibeads may be adapted to prevent release of the steroid in the
stomach and at least the upper small intestine (e.g. duodenum and
jejenum); at least some of the minibeads, e.g. all of them, may be
adapted to prevent release of the steroid in the stomach and the
small intestine. The minibeads may comprise a barrier, for example
a single layer coating or a plural layer coating, to prevent
release of the steroid. The barrier may comprise an enteric polymer
product, for example an enteric coating, or it may comprise an
erodible coating. The barrier may comprise a coating which
comprises a polymer, e.g. a polysaccharide, which is specifically
susceptible to degradation by bacterial enzymes in the colon, i.e.
is susceptible to degradation by bacterial enzymes in the colon but
not by enzymes higher up the GIT; such a coating may or may not
also be erodible.
[0046] In a formulation of the invention, at least a portion of the
steroid may be protected against release in the stomach, and
optionally in the stomach and the small intestine. The formulation
may be adapted for a first portion of the steroid to be released in
the upper gastrointestinal tract, for example in the small
intestine, and a second portion of the steroid to be released in
the colon. The second portion may comprise more than half the
steroid in the formulation, e.g. at least 60%, at least 70% or at
least 80% thereof. As mentioned above, therefore, the formulation
may comprise minibeads and more than half of the minibeads, e.g. at
least 60% of them, at least 70% of them, at least 80% of them or
all of them, may comprise a barrier to prevent release of the
steroid in the stomach and small intestine. The protection against
release or barrier may be provided by a coating selected from:
enteric coatings; coatings adapted to release the steroid in the
colon (e.g. such a coating may be erodible and/or comprise a
polymer specifically susceptible to degradation by bacterial
enzymes in the colon); and coatings comprising a combination of an
enteric coating and a coating comprising a polymer specifically
susceptible to degradation by bacterial enzymes in the colon.
[0047] In a formulation of the invention, therefore, the steroid
may all be comprised in minibeads. A multiplicity of such minibeads
may be comprised in a unit dosage form, for example a gelatine or
other capsule, a sachet, a compressed tablet or a suppository. An
oral steroid formulation of the invention may therefore comprise or
consist of a multiplicity of minibeads and optionally a capsule or
other container for the minibeads. For all aspects and
implementations of the invention, an oral formulation may comprise
a first population of minibeads adapted to release the steroid in
the upper gastrointestinal tract, e.g. in the small intestine, and
a second population of minibeads adapted to release the steroid in
the colon. The first population of minibeads may be coated with an
enteric coating which dissolves in the small intestine; all the
minibeads of the formulation may have such a coating or a portion
thereof. The second population of minibeads may comprise more than
half said steroid in the formulation, e.g. at least 60%, at least
70% or at least 80% thereof. The second population of minibeads may
have a coating adapted to release the steroid in the colon; the
coating may be an erodible coating and/or may comprise a polymer
specifically susceptible to degradation by bacterial enzymes in the
colon, i.e. susceptible to degradation by bacterial enzymes in the
colon but not by enzymes higher up the GIT.
[0048] The formulations of the invention may comprise multiple
seamless minibeads (also known as seamless minicapsules or seamless
minispheres) comprising the steroid. The seamless minibeads may
comprise a water-soluble polymer encapsulating the steroid; such
minibeads may comprise a water-soluble polymer matrix also referred
to herein as the polymer matrix or the matrix and, dispersed in the
matrix, a dispersed phase comprising materials selected from
hydrophobic and amphiphilic materials, and combinations thereof.
The minibeads may comprise a composition having the characteristics
of a dried state of a colloidal system having a continuous aqueous
phase comprising a hydrogel-forming polymer. The colloidal system
may have a dispersed phase selected from a hydrophobic phase, a
water-in-oil emulsion, and a phase comprising self-assembly
structures, for example formed primarily by surfactant. The phase
comprising self-assembly structures may be selected from a micellar
phase selected from micelles, promicelles and combinations thereof.
The matrix, or the hydrogel-forming polymer of the dried colloid,
may comprise a hydrophilic surfactant. The dispersed phase may
comprise a hydrophobic surfactant. For all aspects and
implementations of the invention, the matrix (the hydrogel-forming
polymer, in the case of minibeads comprising such a polymer) may
comprise a hydrophilic surfactant having an HLB value of at least
15 and the dispersed phase may be a hydrophobic phase comprising a
non-ionic surfactant having an HLB value of at least 10 but less
than that of the hydrophilic surfactant.
[0049] The formulation may comprise minibeads coated with an
enteric coating which dissolves in the small intestine; all the
minibeads of the formulation may have such a coating or a portion
thereof.
[0050] The hydrogel-forming polymer or water-soluble polymer may
comprise or consist of gelatin or another thermotropic
hydrogel-forming polymer, or a combination thereof.
[0051] The dispersed phase may comprise an excipient selected from
medium chain triglycerides and polyglycol mono- and di-esters of
12-hydroxystearic acid, and combinations thereof.
[0052] The steroid may be in the form of a liquid solution,
semi-solid solution or solid solution e.g. in a hydrophobic or
amphiphilic medium.
[0053] The invention provides a method of treating a subject,
preferably a warm-blooded animal, e.g. a mammal such as a human, to
treat intestinal fibrosis, which method comprises enterally, e.g.
orally, administering to said animal a steroid. Particular
embodiments of this method comprise the administration of a
formulation as described herein. The formulation may be
administered in a therapeutically effective amount or in a
prophylactically effective amount. The formulation may be
administered to a human patient in need thereof.
[0054] The invention further provides a method of treating a
warm-blooded animal, e.g. a mammal such as a human, to inhibit,
inhibit, reduce or delay the initiation and/or progression of
intestinal fibrosis, which method comprises enterally, e.g. orally,
administering to said animal a steroid. Particular embodiments of
this method comprise the administration of a formulation as
described herein. The formulation may be administered to a human
patient in need thereof.
[0055] The subject treated with the steroid may have at least one
fibrosis-associated disease, condition or state described herein,
for example selected from inflammatory bowel diseases and
enteropathies, and combinations thereof.
[0056] The treatment with the steroid may be to inhibit, delay
and/or reduce progression of intestinal fibrosis, and/or to
inhibit, delay and/or reduce initiation of intestinal fibrosis. The
treatment with the steroid may be to delay and/or reduce
progression of intestinal fibrosis, and/or to delay and/or reduce
initiation of intestinal fibrosis.
[0057] The invention also contemplates combination therapy. It is
to be understood that the combination therapies contemplated herein
may be achieved by way of the simultaneous, sequential or separate
administration of the individual components of the combination(s)
disclosed herein. The individual components may be combined in a
single composition, for example in a single minibead or in a unit
dosage form, e.g. capsule or sachet, containing two or more
populations of mini-units, e.g. minibeads, containing different
actives/combinations of actives.
[0058] The formulations incorporating the steroid may additionally
include a hydroxylase inhibitor or be for use in combination
therapy with a hydroxylase inhibitor. The methods of the invention
may further comprise simultaneous, sequential or separate
administration of a hydroxylase inhibitor, e.g. simultaneously as
part of the same formulation or separately as part of a kit.
[0059] The hydroxylase inhibitor may be selected from DMOG,
hydralazine, FG-4497, FG4095, AGN-2979, metirosine, 3-iodotyrosine,
aquayamycin, bulbocapnine, oudenone, TM 6008, TM 6089, siRNAs
against hydroxylases and antisense therapeutics against
hydroxylases, e.g. against PHD1, and combinations thereof. The
hydroxylase inhibitor may be DMOG. The hydroxylase inhibitor in
particular may be hydralazine. May wish to mention agents that
induce hypoxia-inducible factors, of which hydroxylase inhibitors
as some.
[0060] The formulations incorporating the steroid may additionally
include an immunosuppressant or be for use in combination therapy
with an immunosuppressant. The methods of the invention may further
comprise simultaneous, sequential or separate administration of an
immunosuppressant, e.g. simultaneously as part of the same
formulation or separately as part of a kit.
[0061] The immunosuppressant may be selected from cyclosporins,
tacrolimus, sirolimus pimecrolimus, angiotensin II inhibitors (e.g.
Valsartan, Telmisartan, Losartan, Irbesatan, Azilsartan,
Olmesartan, Candesartan, Eprosartan) and ACE inhibitors e.g.
sulfhydryl-containing agents (e.g. Captopril, Zofenopril),
dicarboxylate-containing agents (e.g. Enalapril, Ramipril,
Quinapril, Perindopril, Lisinopril, Benazepril, Imidapril,
Zofenopril, Trandolapril), phosphate-containing agents (e.g.
Fosinopril), casokinins, lactokinins and lactotripeptides, and
combinations thereof. Preferably, the immunosuppressant is a
cyclosporin, particularly cyclosporin A.
[0062] Those formulations of the invention which include or are for
use in combination therapy with a hydroxylase inhibitor may
include, or be for use in combination therapy with, an
immunosuppressant. The hydroxylase inhibitor and the
immunosuppressant may be as described elsewhere herein. The
immunosuppressant may be a cyclosporin, particularly cyclosporin A.
The hydroxylase inhibitor may be hydralazine or DMOG, in particular
it may be hydralazine.
[0063] Those formulations of the invention which include or are for
use in combination therapy with an immunosuppressant may include,
or be for use in combination therapy with, a hydroxylase inhibitor.
The hydroxylase inhibitor and the immunosuppressant may be as
described elsewhere herein. The immunosuppressant may be a
cyclosporin, particularly cyclosporin A. The hydroxylase inhibitor
may be hydralazine or DMOG, in particular it may be
hydralazine.
[0064] The formulations of the invention comprising a steroid may
therefore further comprise a hydroxylase inhibitor and an
immunosuppressant. The hydroxylase inhibitor and the
immunosuppressant may be as described elsewhere herein. The
immunosuppressant may be a cyclosporin, particularly cyclosporin A.
The hydroxylase inhibitor may be hydralazine or DMOG, in particular
it may be hydralazine.
[0065] The steroid may be any steroid selected from natural or
synthetic steroids.
[0066] In particular, the steroid is budesonide.
[0067] Included in the invention is an enteral formulation, for
example an oral formulation, comprising a steroid and for use in
the treatment of intestinal fibrosis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0068] Embodiments of the invention are further described
hereinafter with reference to the accompanying drawings, in
which:
[0069] FIG. 1 is a plot of weight change showing the effect of a
budesonide formulation of the invention (DSS recovery-Bud), see
Example 12;
[0070] FIG. 2 is a plot of Disease Activity Index (DAI) showing the
effect of a budesonide formulation of the invention (DSS
recovery-Bud), see Example 12;
[0071] FIG. 3 is a bar chart showing colon weight (mg) from the
four mouse groups in the DSS model of fibrosis, see Example 12;
[0072] FIG. 4 is a bar chart showing colon length (mm) from the
four mouse groups in the DSS model of fibrosis, see Example 12;
[0073] FIG. 5 is histology images of colonic tissue of healthy
control specimens in the DSS model of fibrosis, see Example 12;
[0074] FIG. 6 is histology images of colonic tissue of DSS no
recovery specimens in the DSS model of fibrosis, see Example
12;
[0075] FIG. 7 is histology images of colonic tissue of DSS recovery
(natural recovery) specimens after 14 days of recovery in the DSS
model of fibrosis, see Example 12;
[0076] FIG. 8 is histology images of colonic tissue of DSS
recovery-Bud (recovery with treatment with budesonide) specimens
after 14 days of recovery in the DSS model of fibrosis, see Example
12;
[0077] FIG. 9 is a bar chart showing the % Collagen III identified
from colonic histology samples of each of the four mouse groups in
the DSS fibrosis model, see Example 12;
[0078] FIG. 10 is a plot of Disease Activity Index (DAI) showing
the effect of a budesonide-cyclosporin combination formulation of
the invention (DSS recovery-Bud+CyA (uncoated)), see Example
17;
[0079] FIG. 11 is a plot of Disease Activity Index (DAI) graph
showing the effect of a budesonide-cyclosporin combination
formulation of the invention (DSS recovery-Bud+CyA (coated)), see
Example 17;
[0080] FIG. 12 is a plot of Disease Activity Index (DAI) graph
showing the effect of a budesonide-hydralazine combination
formulation of the invention (DSS recovery-Bud+HyA (uncoated)), see
Example 17;
[0081] FIG. 13 is a plot of Disease Activity Index (DAI) graph
showing the effect of a budesonide-hydralazine combination
formulation of the invention (DSS recovery-Bud+HyA (coated)), see
Example 17;
[0082] FIG. 14 shows images of histology of colonic tissue stained
with Masson trichrome showing the incidence of collagen, see
Example 17;
[0083] FIG. 15 is a bar chart showing the % submucosal collagen I
in colonic histology samples of the test groups of Example 17;
[0084] FIG. 16 is a bar chart showing the % submucosal collagen III
in colonic histology samples of the test groups of Example 17.
DETAILED DESCRIPTION
[0085] The present products (steroids, formulations, compositions)
and methods are as previously described for use in the treatment of
intestinal fibrosis. They are therefore for use in the treatment of
fibrotic disorders. The treatments include by way of example
maintenance therapy or prophylaxis as well as treatment to improve
the condition of a patient.
[0086] The invention is predicated on the use of a steroid,
particularly a corticosteroid or an anti-inflammatory steroid or a
first pass metabolised steroid, to treat intestinal fibrosis. The
invention is to be understood accordingly and it not limited,
therefore, to being performed using the formulations described in
this specification, since the choice of formulation is not critical
to the invention.
[0087] Nonetheless, all the formulations described herein
themselves form part of the invention without limitation to the use
to which they are put. The applicant therefore reserves the right
to claim all the formulations described herein in composition of
matter claims. For example, formulations described herein may be
useful for treating celiac disease or other conditions that have
inflammation and fibrosis and part of their pathology. The use of
the formulations described herein to treat intestinal fibrosis is
of course included also in the invention.
[0088] The invention will now be described in detail by reference
to the various components which the composition of the invention
may comprise. The term "excipient" may be used occasionally to
describe all or some of the components other than the active
principle(s) bearing in mind that some excipients can be active and
that some active principles can have excipient character.
[0089] If not otherwise stated, ingredients, components, excipients
etc of the composition of the invention are suitable for one or
more of the intended purposes discussed elsewhere herein.
[0090] For the avoidance of doubt, it is hereby stated that the
information disclosed earlier in this specification under the
heading "Background" is relevant to the invention and is to be read
as part of the disclosure of the invention.
[0091] The terms "active", "active ingredient", "active compound",
etc are used throughout this specification to refer to compounds
that possess a beneficial effect on the human or animal body when
administered thereto. The terms are also used to describe the
steroid of the invention as well as any other active ingredient
that may be used in combination with the steroid. Therefore, where
a feature of the description is referred to as being relevant to an
"active", etc then this feature is applicable to the steroid and
any active ingredients combined with the steroid.
[0092] The terms "dry" and "dried" as applied to compositions of
the disclosure may each include reference to compositions
containing less than 5% free water by weight, e.g. less than 1%
free water by weight. Primarily, however, "dry" and "dried" as
applied to compositions of the disclosure mean that the hydrogel
present in the initial solidified composition has dried
sufficiently to form a rigid composition.
[0093] "Medium chain triglyceride" means a C6-C12 fatty acid
tri-ester of glycerol. Commercially available formulations of
medium chain triglycerides (MCTs) are typically derived from
natural products and contain minor amounts of other components, for
example glycerides of differing chain length, mono- and
di-glycerides and free fatty acid. Such commercially available
formulations are medium chain triglycerides within the meaning of
this specification.
[0094] The term "subject" includes humans and other mammals such as
domestic animals (e.g., dogs and cats), as well as fish. In
particular implementations, the term "subject" denotes a human.
[0095] The term "self-assembly structure" refers to any type of
micelle, -liposome, vesicle, microemulsion, lyotropic phase,
laminar or other self-organised structure that forms spontaneously
in the presence of an aqueous environment, or combination thereof.
As is known, such self-assembly structures form when a
self-assembly structure-forming substance, e.g. comprising or
consisting of a surfactant, is present above a certain critical
concentration. The term includes, for example, micelles, inverted
micelles and liposomes, and combinations thereof. The self-assembly
structures referred to in this specification may comprise, or be,
micelles. More information on self-assembly structures can be found
in "Dynamics of Surfactant Self-assemblies Micelles,
Microemulsions, Vesicles and Lyotropic Phases" by Raoul Zana,
particularly Chapter 1, all of which is incorporated herein by
reference. The release of self-assembly structures from a bead or
other composition may be determined by contacting the composition
with water and observing for such structures by dynamic light
scattering.
[0096] "Effective amount" means an amount sufficient to result in
the desired therapeutic or prophylactic response. The therapeutic
or prophylactic response can be any response that a user (e.g., a
clinician) will recognize as an effective response to the therapy.
It is further within the skill of one of ordinary skill in the art
to determine appropriate treatment duration, appropriate doses, and
any potential combination treatments, based upon an evaluation of
therapeutic or prophylactic response.
[0097] The term "fibrosis" includes reference to conditions in
which excessive connective tissue is present and, therefore, to
conditions in which there is increased collagen deposition compared
to healthy individuals. The term "fibrosis" also includes reference
to conditions in which there is increased deposition of other
extracellular matrix ("ECM") proteins. In this invention, such
collagen and/or other ECM proteins may be deposited in any tissue
of the GIT. In this invention, fibrosis may be induced by any
mechanism and may be associated with any disease or condition
effecting the GIT. Intestinal fibrosis is usually considered to be
a common complication of enteropathies, often with distinct
initiating pathophysiology, for example inflammatory bowel disease
(IBD), radiation enteropathy, graft-versus-host disease,
collagenous colitis, eosinophilic enteropathy, drug-induced
enteropathy, sigmoid diverticulitis, solitary rectal ulcer, cystic
fibrosis, intra-peritoneal fibrotic adhesions, desmoplastic
reaction in gastrointestinal tumors (familial adenomatous
polyposis-FAP), desmoid tumors, gastrointestinal (GI) stromal
tumors (GISTs) and post-surgical intestinal adhesions and
strictures leading to intestinal stenosis and obstruction. The list
of enteropathies in the previous sentence is not a comprehensive
list of enteropathies in which fibrosis may occur: in general all
or most enteropathies may be associated with fibrosis. Fibrosis
associated with these and all other enteropathies is included in
this specification. Fibrosis may be pathogenic or non-pathogenic in
origin. The reader is further referred to the discussion of
fibrosis earlier in this specification under the heading
"Background" and the publications mentioned in that connection, all
of which disclosures are comprised in the meaning of the term
"fibrosis" as used herein. In any event, the term "fibrosis"
includes reference to any condition, state or disorder which is
considered to be fibrosis within the scope of sound medical
judgment.
[0098] The term "enteropathy" refers to a disease or disorder of
the intestinal tract, for example of any one or more regions of the
intestinal tract. The term therefore includes references to all
diseases and disorders of the small intestine, or any of its
regions, and/or of the large intestine, or any of its regions. An
enteropathy may occur as part of, or in the setting of, a systemic
disease or disorder and/or of a disease or disorder which affects
one or more other organs and/or tissues of the body. An enteropathy
may be pathogenic or non-pathogenic in origin. Pathogenic
enteropathies are a particular problem in developing countries
where children infected by various pathogens including GI
pathogens, develop enteropathy with resulting stunted growth,
mental development, risk of infection and other deleterious
consequences. A non-limiting list of examples of enteropathies
which are associated with fibrosis is given in the preceding
paragraph. In any event, the term "enteropathy" includes reference
to any condition, state or disorder which is considered to be an
enteropathy within the scope of sound medical judgment.
[0099] The term "a steroid susceptible to first pass metabolism"
means a steroid which within sound medical judgment, is considered
to undergo first pass metabolism. Therefore, only a part of an
initial steroid dosage becomes systemically available.
[0100] The treatments provided by this invention may include any
one or more of: maintaining the gastrointestinal health of a
subject who has or is at risk of having gastrointestinal fibrosis;
restoring or improving the gastrointestinal health of a subject who
has or is at risk of having gastrointestinal fibrosis; reducing or
controlling gastrointestinal fibrosis; delaying the progression of
gastrointestinal fibrosis; delaying, avoiding the need for or
reducing the likelihood of surgical intervention to treat
gastrointestinal fibrosis, for e.g. to treat strictures. Such
treatments of gastrointestinal fibrosis may be part of a
combination therapy regime for the treatment of a gastrointestinal
disorder having, or at risk of having, a fibrotic aspect.
[0101] The term "treatment", and the therapies encompassed by this
invention, include the following and combinations thereof: (1)
inhibiting, e.g. delaying initiation and/or progression of a state,
disorder or condition; (2) preventing or delaying the appearance of
clinical symptoms of a state, disorder or condition developing in
an animal (e.g. human) that may be afflicted with or predisposed to
the state, disorder or condition but does not yet experience or
display clinical or subclinical symptoms of the state, disorder or
condition; (3) inhibiting the state, disorder or condition (e.g.,
arresting, reducing or delaying the development of the disease, or
a relapse thereof in case of maintenance treatment, of at least one
clinical or subclinical symptom thereof); and/or (4) relieving a
state disorder or condition (i.e., causing regression of the state,
disorder or condition or at least one of its clinical or
subclinical symptoms). The benefit to a patient to be treated may
be either statistically significant or at least perceptible to the
patient or to the physician. It will be understood that a
medicament will not necessarily produce a clinical effect in every
patient to whom it is administered, and this paragraph is to be
understood accordingly. The compositions and methods described
herein are of use for therapy and/or prophylaxis of the conditions
mentioned herein. The terms "state", "disorder" and "condition"
refer herein to a state, disorder or condition which is associated
with gastrointestinal fibrosis, for example which carries with it
an increased risk of gastrointestinal fibrosis as compared to the
risk of a normal population. In particular, the state, order or
condition treated by a steroid in accordance with the invention is
gastrointestinal fibrosis; the gastrointestinal fibrosis may be
treated prophylactically in a subject who has not experienced
gastrointestinal fibrosis but is at increased risk of suffering
from it, for example because the subject suffers at least
intermittently, e.g. continuously, from an inflammatory bowel
disease. Alternatively, the gastrointestinal fibrosis may be
treated therapeutically or prophylactically in a subject who
suffers from gastrointestinal fibrosis, in particular to arrest,
inhibit, reduce or delay progression of such gastrointestinal
fibrosis.
[0102] The treatments may include maintenance therapy of patients
who have suffered a GI tract disorder and whose condition has
subsequently improved, e.g. because of treatment. Such patients may
or may not suffer a symptomatic GIT disorder. Maintenance therapy
aims to arrest, inhibit, reduce or delay (re-)occurrence or
progression of a GIT disorder.
[0103] The invention primarily concerns the treatment of humans but
other warm-blooded animals, e.g. mammals, are also embraced by the
invention, for example agricultural mammals and domesticated
mammals. Examples are pigs, dogs and cats. For example, the
compositions and methods of the invention may be applied to porcine
proliferative enteropathy.
[0104] The subject may be suffering from an inflammatory bowel
disease. The subject may be suffering from Crohn's disease. The
subject may be suffering from ulcerative colitis. The subject may
be suffering from irritable bowel syndrome (e.g. with constipation,
diarrhea and/or pain symptoms), celiac disease, stomach ulcers,
diverticulitis, pouchitis, proctitis, mucositis,
radiation-associated enteritis, short bowel disease, or chronic
diarrhea. The subject may be suffering from GVHD. As used herein,
"GVHD" in particular means GI-GVHD (gastrointestinal
graft-versus-host disease). The subject may be suffering from
diversion colitis, ischemic colitis, infectious colitis, chemical
colitis, microscopic colitis (including collagenous colitis and
lymphocytic colitis), atypical colitis, pseudomembraneous colitis,
fulminant colitis, autistic enterocolitis, interdeminate colitis,
Behcet's disease, jejunoiletis, ileitis, ileocolitis and
granulomatous colitis. The invention in its aspects and
implementations is applicable to subjects having the disorders
mentioned in this paragraph, therefore.
[0105] The subject may be suffering from an enteropathy, for
example gluten-sensitive enteropathy, hemorrhagic enteropathy,
protein-losing enteropathy, radiation enteropathy, enteropathy
associated with T-cell lymphoma, autoimmune enteropathy or porcine
proliferative enteropathy, or any other enteropathy mentioned in
this specification. The subject may be suffering from an
enteropathy not mentioned in this specification. Colorectal
carcinoma and adenocarcinoma are inflammation-related diseases. The
treatments and products described herein are useful for patients
who have suffered from, do suffer from or have risk factors for,
such cancers. The disclosed therapies and products may be used in
(e.g. as part of) the treatment of colorectal carcinomas or as part
of the maintenance therapies of patients who have suffered from
such carcinomas (in this regard, there is considered to be a strong
inflammation component in the aetiology of colorectal cancer). The
invention in its aspects and implementations is applicable to
subjects having the disorders mentioned in this paragraph.
[0106] Solubilities of compounds, e.g. actives, in a solvent (for
example water) may be defined as follows, the solubility being
measured at 25.degree. C. and parts being by weight:
TABLE-US-00001 Descriptive Team Parts of Solvent for 1 part of
solute Very Soluble Less than 1 Freely Soluble From 1 to 10 Soluble
From 10 to 30 Sparingly Soluble From 30 to 100 Slightly Soluble
From 100 to 1000 Very Slightly Soluble From 1000 to 10,000
Practically Insoluble More than 10,000
[0107] Typically, but not necessarily, the invention provides that
active agents which are practically insoluble, very slightly
soluble or sparingly soluble in water are in the form of a liquid,
semi-solid or solid solution in a hydrophobic or amphiphilic
environment, e.g. medium.
[0108] Actives which are not particularly water-soluble, e.g. are
practically insoluble, very slightly soluble or slightly soluble,
perhaps even are sparingly soluble, may be more soluble in a
suitable dispersed phase of a minibead than in the aqueous phase,
and may therefore advantageously be incorporated in the dispersed
phase. Steroids are typical examples of such actives.
Active Agents
[0109] The invention is based on the use of a steroid to treat
gastrointestinal fibrosis.
[0110] The steroid may be a corticosteroid. Such corticosteroids
generally may be any steroid produced by the adrenal cortex,
including glucocorticoids and mineralocorticoids, and synthetic
analogues and derivatives of naturally occurring corticosteroids
having anti-inflammatory activity. Examples of corticosteroids that
can be used are aclometasone, aclometasone dipropionate,
aldosterone, amcinonide, beclomethasone, beclomethasone
dipropionate, betamethasone, betamethasone dipropionate,
betamethasone sodium phosphate, betamethasone valerate, budesonide,
clobetasone, clobetasone butyrate, clobetasol propionate,
cloprednol, cortisone, cortisone acetate, cortivazol, deoxycortone,
desonide, desoximetasone, dexamethasone, dexamethasone sodium
phosphate, dexamethasone isonicotinate, difluorocortolone,
fluclorolone, flumethasone, flunisolide, fluocinolone, fluocinolone
acetonide, fluocinonide, fluocortin butyl, fluorocortisone,
fluorocortolone, fluocortolone caproate, fluocortolone pivalate,
fluorometholone, fluprednidene, fluprednidene acetate,
flurandrenolone, fluticasone, fluticasone propionate, halcinonide,
hydrocortisone, hydrocortisone acetate, hydrocortisone butyrate,
hydrocortisone aceponate, hydrocortisone buteprate, hydrocortisone
valerate, icomethasone, icomethasone enbutate, meprednisone,
methylprednisolone, mometasone paramethasone, mometasone furoate
monohydrate, prednicarbate, prednisolone, prednisone, tixocortol,
tixocortol pivalate, triamcinolone, triamcinolone acetonide,
triamcinolone alcohol and their respective pharmaceutically
acceptable derivatives. A combination of steroids may be used, for
example a combination of two or more steroids mentioned in this
paragraph.
[0111] The steroids used in the present invention may be
water-soluble, water-insoluble or water-dispersible. The steroids
used in the present invention may be oil-soluble, oil-insoluble or
oil-dispersible. Water-soluble corticosteroids may be salts, for
example alkali metal or ammonium salts, prepared from a
corticosteroid having a free hydroxyl group and an acid. The acid
may be an organic acid, for example a C2-C12 aliphatic, saturated
or unsaturated dicarboxylic acid, or an inorganic acid, for example
phosphoric acid or sulphuric acid. Also, acid-addition salts of
corticosteroids may be used. If more than one group in the
corticosteroid molecule is available for salt formation, mono-, as
well as di-, salts may be useful. As alkaline metal salts, the
potassium and sodium salts are preferred. Other positively or
negatively charged derivatives of corticosteroids can also be used.
Specific examples of water-soluble corticosteroids are
betamethasone sodium phosphate, desonide sodium phosphate,
dexamethasone sodium phosphate, hydrocortisone sodium phosphate,
hydrocortisone sodium succinate, methylprednisolone disodium
phosphate, methylprednisolone sodium succinate, prednisolone sodium
phosphate, prednisolone sodium succinate, prednisolamate
hydrochloride, prednisone disodium phosphate, prednisone sodium
succinate, triamcinolone acetonide disodium phosphate and
triamcinolone acetonide disodium phosphate.
[0112] Water-soluble steroids may be salts, for example
betamethasone phosphate, dexamethasone phosphate, prednisolone
phosphate, prednisolone succinate, hydrocortisone succinate.
[0113] Of these water-soluble steroids, prednisolone disodium
phosphate, prednisolone sodium succinate, methylprednisolone
disodium phosphate, methylprednisolone sodium succinate,
dexamethasone disodium phosphate and betamethasone disodium
phosphate may be mentioned in particular.
[0114] Topical corticosteroids which are susceptible to first pass
metabolism are of special interest. Examples thereof are
budesonide, flunisolide, fluticasone proprionate, rimexolone,
butixocort, tixocortol and beclomethasone. It will be understood
that these compounds may be in the form of the salts, esters,
conjugates and prodrugs thereof, for example one mentioned
elsewhere in this specification.
[0115] Salts, prodrugs, esters, conjugates, stereoisomers,
enantiomers and solvates of the steroids mentioned herein may be
used to perform the invention. Esters may be esters of aliphatic
acids, for example fatty acids. Prodrugs, esters and conjugates may
be in the form of salts. In this case of steroid salts mentioned
herein, instead of being used as the mentioned salt, the steroid
may be used as another salt, as the free compound or as a
conjugate, ester or prodrug, which conjugates, esters and prodrugs
may be in salt form.
[0116] The steroid may be budesonide. The steroid may be a
combination of steroids comprising budesonide.
[0117] Budesonide may be in the form of the free molecule or it may
be as a conjugate or prodrug thereof, which conjugates and prodrugs
may, where they have an acidic or basic group, be in salt form. As
an example may be mentioned budesonide-beta-D-glucuronide, which is
not absorbed in the small intestine but is hydrolysed by colonic
bacterial and mucosal beta-glucuronidase to release free budesonide
into the colon. Also to be mentioned are budesonide-dextran
conjugates and budesonide esters.
[0118] The formulations useful in performing the invention include
any enteral formulations whose administration results in release of
a corticosteroid, for example budesonide or another corticosteroid
mentioned in this specification.
[0119] In particular, therefore, the invention provides budesonide
for use in treating intestinal fibrosis. Also provided is the use
of budesonide for the manufacture of a medicament for treating
intestinal fibrosis.
[0120] The steroid, which in particular may be budesonide, may be
used in combination therapy with one or more other active
agents.
[0121] The steroid may be used in combination therapy with another
steroid, e.g. a plurality of other steroids or a single other
steroid, and optionally with one or more active agents other than
steroids.
[0122] In the case of combination therapy, the active agents may be
administered simultaneously, separately or sequentially. The
combination of active agents may be in the form of a fixed
combination, i.e. all included in the same formulation. Where three
or more active agents are administered in combination therapy, a
sub-combination of e.g. two of the active agents may be in the form
of a fixed combination.
[0123] The steroid may be used in combination therapy with a
methylxanthene, for example theophylline, to overcome, modulate,
treat or inhibit steroid resistance. The steroid may be used in
combination therapy with a single methylxanthene or a combination
of methylxanthenes.
[0124] In the case of combination therapy, the active agent(s)
administered as well as the steroid may be selected from active
agents useful for treating inflammatory bowel diseases. For example
such active agents may be selected from immunosuppressants and
direct or indirect promoters of the activity or expression of
hypoxia-inducible factor (HIF), particularly HIF-1, and
combinations of the aforegoing. Promoters of the activity or
expression of hypoxia-inducible factor (HIF), particularly
HIF-1
[0125] The steroid may therefore be used in combination therapy
with an immunosuppressant. The identity of the immunosuppressant is
not critical. It may be, or comprise, any one or more of: a
calcineurin inhibitor, cyclosporin A (ciclosporin); mTOR
inhibitors, e.g. sirolimus (rapamycin), sirolimus derivatives for
example everolimus, 32-deoxorapamycin; a mycophenolate, eg.
mycophenolic acid; methotrexate; azathioprine or mercaptopurine;
mitoxantrone; cyclophosphamide; macrolide immunosuppressant,
angiotensin II inhibitors (e.g. Valsartan, Telmisartan, Losartan,
Irbesatan, Azilsartan, Olmesartan, Candesartan, Eprosartan) and ACE
inhibitors e.g. sulfhydryl-containing agents (e.g. Captopril,
Zofenopril), dicarboxylate-containing agents (e.g. Enalapril,
Ramipril, Quinapril, Perindopril, Lisinopril, Benazepril,
Imidapril, Zofenopril, Trandolapril), phosphate-containing agents
(e.g. Fosinopril), casokinins, lactokinins and
lactotripeptides.
[0126] The steroid may be used in combination therapy with an
active agent selected from calcineurin inhibitors, macrolide
immunosuppressants and mTOR inhibitors.
[0127] Exemplary calcineurin inhibitors are cyclosporins,
tacrolimus, and pimecrolimus.
[0128] For examples of mTOR inhibitors useful in the invention the
reader is referred to WO2007/068462, which is incorporated herein
by reference in its entirety. Particular examples are rapamycin,
40-O-(2-hydroxy)-ethyl-rapamycin, 32-deoxorapamycin,
40-[3-hydroxy-2-(hydroxy-methyl)-2-methylpropanoate]-rapamycin,
ABT578 and AP23573.
[0129] As examples of macrolide immunosuppressants may be mentioned
tacrolimus, ascomycins, sirolimus, cyclosporin, pimecrolimus.
[0130] It will be recalled that the steroid may be used in
combination therapy with a direct or indirect promoters of the
activity or expression of HIF-1. To be mentioned as indirect
promoters of the activity or expression of HIF-1 are hydroxylase
inhibitors. Such hydroxylase inhibitors may inhibit an asparaginyl
hydroxylase; it may inhibit a prolyl hydroxylase; it may inhibit
both. The hydroxylase inhibitor may be selected from, or comprise,
DMOG, hydralazine, FG-4497, FG4095, AGN-2979, metirosine,
3-iodotyrosine, aquayamycin, bulbocapnine, oudenone, TM 6008, TM
6089, siRNAs against hydroxylases and antisense therapeutics
against hydroxylases, e.g. against PHD1, and combinations thereof.
In any event, two or more hydroxylase inhibitors may be used.
[0131] The steroid, in particular budesonide, may be used in
combination therapy with another anti-fibrotic agent, for example
selected from caspase inhibitors, peroxisome proliferator-activated
receptor-g (PPAR-g) agonists such as pioglitazone, TGF-b blockers,
colchicines, relaxin, adiponectin, endothelin A, angiotensin
receptor blockers, cannabinoids and agents altering the MMP-TIMP
balance, and wound healing agent (Ilodecakin,
Mannose-6-Phosphate).
[0132] The steroid, in particular budesonide, may therefore be used
in combination therapy with one, two or three of (a), (b) and (c)
below: [0133] (a) an immunosuppressants; [0134] (b) a promoter of
the expression or activity of HIF, for example a hydroxylase
inhibitor; [0135] (c) another anti-fibrotic agent.
[0136] In particular, such combination therapy may use the steroid,
particularly budesonide, an immunosuppressant and a hydroxylase
inhibitor. The immunosuppressant may be cyclosporin A. The
hydroxylase inhibitor may DMOG or hydralazine.
[0137] The disclosure therefore includes a steroid, in particular
budesonide, for use in treating intestinal fibrosis in combination
therapy with: [0138] (i) cyclosporin A; or [0139] (ii) DMOG; or
[0140] (iii) hydralazine; or [0141] (iv)cyclosporin A and DMOG; or
[0142] (v) cyclosporin A and hydralazine. The combination therapy
may include use of one or more additional active agents.
[0143] In those instances where the steroid is for use in
combination therapy, the steroid and the active agent or agents
with which the steroid is for use in combination therapy are all
comprised in a fixed combination.
[0144] This specification describes elsewhere steroid formulations
in the form of minibeads which comprise a water-soluble polymer
matrix and, dispersed in the matrix, a dispersed phase comprising
materials selected from hydrophobic and amphiphilic materials, and
combinations thereof. In particular, such minibeads may comprise a
dried aqueous colloid. The steroids of the disclosure are generally
included in the dispersed phase, typically in solution in the
dispersed phase. Such minibeads may contain one or more active
agents in addition to the steroid.
[0145] An active agent used in combination therapy with the steroid
may be water-soluble or water-dispersible and dissolved or
dispersed in a water-soluble polymer, e.g. a hydrogel-forming
polymer, comprised in the formulation in which the steroid is
incorporated. The polymer may constitute the polymer matrix of a
minibead or dried colloidal formulation as extensively described
herein.
[0146] An active agent used in combination therapy with the steroid
may be hydrophobic and dissolved in a hydrophobic medium, e.g. an
oil, a wax or the interior of a micelle or other self-assembly
structure comprised in the formulation in which the steroid is
incorporated. The oil, wax or micelle may form the dispersed phase
of a minibead or dried colloidal formulation as extensively
described herein.
[0147] The steroid and active agent(s) may be in solution in a
liquid (e.g. an oil or a self-assembly structure) or in a solid or
semi-solid medium (e.g. a wax or a water-soluble polymer). However,
water-soluble or water-dispersible active agents in particular may
be included in the polymer matrix of a minibead in particulate
form, for example as a dried aqueous dispersion. Solid particulate
forms may be microparticles or nanoparticles.
[0148] In certain formulations of the invention the steroid is a
water-soluble steroid. Where the steroid is water soluble it is
dissolved and/or dispersed in the water soluble polymer matrix of a
minibead. The water-soluble steroid may be in combination with a
further water-soluble active ingredient, for example another
steroid or a hydroxylase inhibitor, such as hydralazine. In this
case both water-soluble actives may be present in the water-soluble
polymer matrix. Where the steroid is water-soluble the formulation
may not contain a dispersed phase. Formulations of the present
invention may contain a water-soluble steroid present in solution
in the water-soluble polymer matrix and an oil soluble active
ingredient present in the dispersed phase, for example another
steroid or an immunosuppressant, such as cyclosporin A.
[0149] The minibeads of the disclosure, therefore, provide a
hydrophilic environment (the water-soluble polymer) for hydrophilic
drugs and a hydrophobic environment (the dispersed phase) for
hydrophobic drugs. Hydrophobic drugs are typically in solution in
the dispersed phase but suspensions are not excluded. Hydrophilic
drugs are often also in solution in the matrix phase, but may be
particulate, e.g. as nanoparticles, in the matrix phase.
[0150] It will be understood that, where the steroid and one or
more other actives are used in combination therapy they may be in a
combination formulation. For example, two or more actives may be
included in a single population of minibeads (each minibead
contains the combination of actives), as already described.
Alternatively a composition (e.g. capsule or other container) may
comprise two or more different populations of minibead, the
minibeads of each population having one or more actives not found
in the other population; for example, there may be two minibead
populations, each containing a single active agent different from
that in the other population. As another alternative, any two
actives which are co-administered may be administered in separate
formulations, e.g. simultaneously, separately or sequentially and
often simultaneously (i.e. more or less at the same time).
Formulations
[0151] The invention provides amongst other things pharmaceutical
formulations comprising a steroid and for use in a treatment as
mentioned herein. The formulations may be for enteral use, for
example oral or rectal use. The formulations comprise at least one
steroid and optionally another active agent as specified herein.
The identity of the formulation used to administer the steroid is
not critical to the invention. By way of example, the formulations
may be multiple mini-unit formulations, e.g. multiple minitablet or
multiple minibead formulations, i.e. comprise a multiplicity of
minibeads, for example at least 25 minibeads, e.g. at least 50
minibeads.
[0152] The active compounds may be in finely divided form, for
example it may be micronised.
[0153] The formulations may comprise minibeads and the minibeads
may comprise or consist of minibeads in which the content of at
least hydrophobic active agent(s) is in dissolved form, i.e. is in
solution.
[0154] The formulations may comprise a water-soluble polymeric
matrix in which said active agent(s) is or are dispersed or
dissolved, the matrix in particular forming minibeads which may
additionally comprise one or more coatings. The polymer material
constituting the matrix may be, or may comprise, a hydrogel-forming
polymer. The polymer part of the matrix may therefore consist of a
hydrogel-forming polymer. The formulations may comprise minibeads
comprising a polymeric matrix phase and a dispersed phase. Thus the
formulations may comprise minibeads comprising a hydrogel-forming
polymer and a dispersed phase. Water-soluble actives may be
dissolved in the polymeric matrix or dispersed in the polymeric
matrix in particulate form, e.g. as micro- or nano-particles. The
term "water-soluble" in this paragraph and elsewhere in the
specification includes reference to substances which are
categorised as soluble, freely soluble and very soluble. It may
include reference to substances which are sparingly soluble.
[0155] The matrix may include in addition to the water-soluble
polymer and any dissolved active(s), other ingredients such as, for
example, excipients which may, for example, modulate the behaviour
of the matrix phase and/or of other constituents during manufacture
and/or after administration.
[0156] The matrix advantageously comprises a hydrophilic surfactant
having an HLB value of at least 10 and particularly of at least
15.
[0157] The hydrophilic surfactant may have an HLB value of at least
15, and optionally of at least 18, e.g. of at least 20 or at least
25.
[0158] The hydrophilic surfactant may be an anionic surfactant. The
anionic surfactant may have an HLB value of at least 30, e.g. at
least 35, for example of 40.+-.2. The anionic surfactant may
comprise or be an alkyl sulfate salt. The alkyl sulfate salt may be
sodium dodecyl sulfate (SDS). The water-soluble polymer matrix
material may further contain a non-ionic surfactant having an HLB
value of at least 10 but less than that of the hydrophilic
surfactant. The non-ionic surfactant may comprise a
poly(oxyethylene) group, e.g. comprise a glycerol polyethylene
glycol ricinoleate (as in the case of Cremophor EL).
[0159] The hydrophilic surfactant may be selected from cationic and
non-ionic surfactants, and combinations thereof.
[0160] The formulations may comprise gelatin as a water-soluble
polymer. The gelatin may be the sole water-soluble polymer.
[0161] The water-soluble matrix material may be selected from a
hydrocolloid, a non-hydrocolloid gum and chitosan and derivatives
thereof.
[0162] The formulations may comprise a unit solid which may be a
minibead having a diameter of not more than 10 mm, e.g. of not more
than 5 mm, the formulation optionally comprising a plurality of
such minibeads. The minibead may be monolithic, optionally with
layers thereon. The one or more minibeads may comprise a
controlled-release polymer, e.g. incorporated in the matrix and/or
coated on it. The minibeads may comprise plural controlled release
polymers, which may be present as a mixture or be separated, e.g. a
first controlled-release polymer may be comprised in a coat and a
second (different) controlled-release polymer may be comprised in
the matrix. The or each polymer may be associated with one or more
excipients, e.g. a pore former. At least one controlled-release
polymer may be an extended release polymer or an enteric polymer.
The minibead(s) may have a coat which comprises the controlled
release polymer and optionally a polymer specifically susceptible
of degradation by bacterial enzymes.
[0163] In embodiments, the or each minibead comprises a
controlled-release polymer which is ethylcellulose comprised in a
coating on the minibead and optionally in association with an
emulsification agent, for example ammonium oleate. The
ethylcellulose may also be in association with a plasticizer, e.g.
dibutyl sebacate or medium chain triglycerides. The coating may
further comprise a polymer specifically susceptible of degradation
by bacterial enzymes. The polymer susceptible of degradation by
bacterial enzymes may be water-soluble, and preferably is
pectin.
[0164] The dispersed phase may be composed of, or predominantly of,
hydrophobic and/or amphiphilic materials in which hydrophobic
active(s) may be dissolved. Generally, the dispersed phase may
provide a hydrophobic environment either in a hydrophobic material
or within a hydrophobic part of a self-assembly structure. The
dispersed phase may comprise a water-immiscible liquid. The
water-immiscible liquid may be present in the minicapsules as
droplets. The water-immiscible liquid may comprise a liquid lipid
and optionally a solvent miscible therewith, in which solvent a
water-insoluble active ingredient is soluble. The liquid lipid may
be a medium chain triglyceride (MCT) composition, the medium chain
triglyceride(s) being one or more triglycerides of at least one
fatty acid selected from C.sub.6-C.sub.12 fatty acids
[0165] The liquid lipid may be a caprylic/capric triglyceride, i.e.
a caprylic/capric triglyceride composition (which it will be
understood may contain minor amounts of compounds which are not
caprylic/capric triglycerides).
[0166] For all embodiments of the invention, a water-insoluble
active ingredient may have a solubility in the water-immiscible
liquid of at least 5 mg/ml, and often of at least 10 mg/ml, e.g. at
least 25 mg/ml, for example at least 50 mg/ml.
[0167] The solvent which is optionally included in a
water-immiscible liquid may be miscible with both the liquid lipid
and with water, e.g. it may be 2-(2-ethoxy)ethanol.
[0168] The dispersed phase, e.g. water-immiscible phase
(water-immiscible droplets), may represent from 10-85% by dry
weight of the composition.
[0169] The unit solid or minibead may have a low water content.
[0170] In an embodiment the pharmaceutical formulation is a capsule
or other unit comprising a population of minibeads which have a
diameter of at most 10 mm and which comprise a hydrophilic
surfactant-containing water-soluble polymer matrix material and a
coating on the matrix material, wherein the hydrophilic surfactant
has an HLB value of at least 15, and wherein the coating comprises
a controlled-release polymer. The coating may be a barrier membrane
for extended release of the active agent(s) and/or may be a coating
which resists becoming degraded or becoming of increased
permeability in the conditions of the GI tract above the colon but
which becomes degraded or of increased permeability in the
conditions of the colon. The minibeads may further comprise in the
polymer matrix part a non-ionic surfactant comprising a
poly(oxyethylene) group and the hydrophilic surfactant may be an
anionic surfactant. The capsule or other unit may comprise a second
population of minibeads.
[0171] For all embodiments of the invention, the formulation may
further comprise another active pharmaceutical ingredient, in
addition to a steroid.
[0172] The formulation may comprise a gelatin or other capsule
containing a plurality of minibeads into which the water-soluble
polymer matrix material is formed.
[0173] Also disclosed is a method of making dried colloid
formulations of the disclosure, which method comprises mixing a
water immiscible phase, the dispersed phase, with an aqueous phase,
the continuous phase, comprising a water-soluble polymer matrix
material to form a liquid colloid and then causing the liquid
colloid to solidify. The liquid colloid may be formed into droplets
which are then exposed to a solidification medium (e.g. a liquid
colloid in which the water-soluble polymer is a thermotropic
hydrogel-forming polymer is exposed to a cool water-immiscible oil
to cool the polymer so that it gels). In the case of a dried
emulsion formulation, the water-immiscible phase is hydrophobic. In
the case of a dried self-assembly structure composition, the
water-immiscible phase is usually a surfactant phase (also normally
containing components additional to the surfactant).
[0174] The invention includes a colloidal composition, e.g. an
emulsion or aqueous self-assembly structure composition, useful in
making the formulations of the invention and comprising a steroid,
for example in solution in the water-immiscible phase of the
colloid.
[0175] Further provided is an emulsion for use in manufacturing a
minibead of the disclosure, the emulsion comprising a water
immiscible phase (e.g. oil droplets or micelles or other
self-assembly structures) dispersed in an aqueous phase, wherein
the aqueous phase comprises a water-soluble polymer matrix material
and in that the emulsion comprises a steroid, e.g. in solution.
[0176] The invention further includes a pharmaceutical formulation
for oral administration, obtainable by: [0177] (A) mixing together
at least the following materials to form a colloid: [0178] i) a
steroid; [0179] ii) an aqueous phase comprising water and a
water-soluble polymer material; [0180] iii) a hydrophobic liquid or
a self-assembly structure-forming surfactant; [0181] iv) optionally
a hydrophilic surfactant having an HLB value of at least 10; [0182]
v) optionally one or more excipients which are miscible with or
soluble in the hydrophobic liquid or the self-assembly
structure-forming surfactant to increase the solubility of the
steroid in said liquid or surfactant, wherein the steroid is
soluble in the hydrophobic liquid or self-assembly
structure-forming surfactant when combined with any said one or
more excipients; and [0183] (B) formulating the colloid into a
pharmaceutical composition comprising a unit solid which comprises
the colloid in a dry state. The composition may be adapted to
release the steroid at least into the colon.
[0184] The mixing together may comprise mixing the steroid, the
hydrophobic liquid or self-assembly structure-forming surfactant,
any said one or more excipients and any other constituents soluble
in the hydrophobic liquid or self-assembly structure-forming
surfactant to form a clear solution. Similarly, the water is mixed
with the water-soluble polymer material, the hydrophilic surfactant
(where present) and any other constituents of the aqueous phase of
the colloid. The clear solution is then mixed with the aqueous mix
to form the colloid.
[0185] The formulating may comprise ejecting the emulsion through a
single-orifice nozzle, e.g. having a diameter of from 0.5-5 mm, to
form drops which are then caused or allowed to fall into a cooling
oil or other hardening medium and allowed to harden to form
minibeads, after which the minibeads are recovered from the cooling
oil and dried.
[0186] All optional features previously described in relation to
the invention are applicable to the below described methods and all
other aspects and embodiments of the invention. Likewise, optional
features described in relation to the below described methods are
applicable to embodiments and aspects of the invention described
earlier and later in this specification.
Surfactants
[0187] In the description and claims of this specification, the
term "surfactant" is employed as a contraction for "surface active
agent". For the purposes of this description and claims, it is
assumed that there are four major classifications of surfactants:
anionic, cationic, non-ionic, and amphoteric (zwitterionic). The
non-ionic surfactant remains whole, has no charge in aqueous
solutions, and does not dissociate into positive and negative ions.
Anionic surfactants are water-soluble, have a negative charge and
dissociate into positive and negative ions when placed in water.
The negative charge lowers the surface tension of water and acts as
the surface-active agent. Cationic surfactants have a positive
charge, and also dissociate into positive and negative ions when
placed in water. In this case, the positive ions lower the surface
tension of the water and act as the surfactant. The amphoteric
(zwitterionic) surfactant assumes a positive charge in acidic
solutions and performs as a cationic surfactant, or it assumes a
negative charge in an alkaline solution and acts as an anionic
surfactant.
[0188] Surfactants can also be classified according to their
hydrophilic-lipophilic balance (HLB) which is a measure of the
degree to which the surfactant is hydrophilic or lipophilic,
determined by calculating values for the different regions of the
molecule, as described (originally for non-ionic surfactants) by
Griffin in 1949 and 1954 and later by Davies. The methods apply a
formula to the molecular weight of the whole molecule and of the
hydrophilic and lipophilic portions to give an arbitrary
(semi-empirical) scale up to 40 although the usual range is between
0 and 20. An HLB value of 0 corresponds to a completely hydrophobic
molecule, and a value of 20 would correspond to a molecule made up
completely of hydrophilic components. The HLB value can be used to
predict the surfactant properties of a molecule:
TABLE-US-00002 HLB Value Expected properties 0 to 3 antifoaming
agent from 4 to 6 W/O emulsifier from 7 to 9 wetting agent from 8
to 18 an O/W emulsifier from 13 to 15 typical of detergents 10 to
18 solubiliser or hydrotrope
[0189] Although HLB numbers are assigned to surfactants other than
the non-ionic, for which the system was invented, HLB numbers for
anionic, cationic, and amphoteric (zwitterionic) surfactants can
have less significance and often represent a relative or
comparative number and not the result of a mathematical
calculation. This is why it is possible to have surfactants above
the "maximum" of 20. HLB numbers can however be useful to describe
the HLB requirement of a desired application for a given emulsion
system in order to achieve good performance.
Dried Colloid Compositions
[0190] The formulations of the invention may comprise unit solids
comprising an optionally coated dried colloid composition. The
dried colloid may be a dried emulsion or a dried aqueous micellar
composition. The colloid in its wet liquid form comprises an
aqueous phase comprising a water-soluble polymer and, dispersed
therein, a liquid water-immiscible phase. The liquid
water-immiscible phase may also be referred to herein as the
dispersed phase. In the dry form, the water-soluble polymer forms a
polymeric matrix containing other components of the dried colloid
composition. For convenience, the dried aqueous phase may be
referred to as e.g. the "aqueous phase", the "matrix phase" or the
"polymer phase".
Hydrophilic Surfactants for the Aqueous Phase
[0191] In embodiments of the invention, the unit solid comprises a
hydrophilic surfactant which, without being bound by theory, is
believed at least partially to partition in the aqueous phase
(polymer matrix). In a typical manufacturing process, the
hydrophilic surfactant and other hydrophilic constituents of the
colloid are combined with the water to form an aqueous premix,
which is then combined with a premix of the constituents of the
water-immiscible phase of the colloid to form the liquid
colloid.
[0192] Surfactants for such inclusion in the aqueous phase are
preferably readily diffusing or diffusible surfactants to
facilitate manufacturing and processing of the composition of the
invention. The surfactant may have an HLB of at least 10 and
optionally of at least 15, e.g. at least 30 and optionally of
38-42, e.g. 40. Such surfactants can be of any particular type
(cationic, anionic, non-ionic, zwitterionic) and may comprise as a
proportion of dry weight of the composition from 0.1% to 6%, e.g.
0.1% to 5%. 0.1% to 4% or 0.1% to 3%, e.g. in a proportion of at
least 1% and in particular between 1.0 and 4.5 or 5%, for example
within or just outside the 2-4% range, for example from 2 to 3% or
approximately 2% or approximately 4%. The invention includes
formulations in which the hydrophilic surfactant is, or comprises,
an anionic surfactant, e.g. a single anionic surfactant or a
mixture thereof. Therefore, the hydrophilic surfactant may be an
anionic surfactant.
[0193] Unless otherwise stated or required, all percentages and
ratios are by weight.
[0194] Preferred anionic surfactants for inclusion in the aqueous
phase include perfluoro-octanoate (PFOA or PFO),
perfluoro-octanesulfonate (PFOS), sodium dodecyl sulfate (SDS),
ammonium lauryl sulfate, and other alkyl sulfate salts, sodium
laureth sulfate, also known as sodium lauryl ether sulfate (SLES)
and alkyl benzene sulfonate. A particular class of surfactant
comprises sulfate salts. A preferred anionic surfactant in the
aqueous phase is SDS. A single anionic surfactant may be included
in the aqueous phase or a combination of anionic surfactants.
[0195] The physical form of the surfactant at the point of
introduction into the aqueous phase during preparation plays a role
in the ease of manufacture of the composition according to the
invention. As such, although liquid surfactants can be employed, it
is preferred to utilize a surfactant which is in solid form (e.g.
crystalline, granules or powder) at room temperature, particularly
when the aqueous phase comprises gelatin.
[0196] Possible non-ionic surfactants for the aqueous phase include
perfluorocarbons, polyoxyethyleneglycol dodecyl ether (e.g. Brij
such as, for example, Brij 35), Myrj (e.g. Myrj 49, 52 or 59),
Tween 20 or 80 (also known as Polysorbate). Brij, Myrj and Tween
products are available commercially from Croda.
[0197] In general, mixtures of surfactants can be utilised e.g. to
achieve optimum long term stability of the composition of the
invention with shorter chain surfactants in general facilitating
shorter term stability (an aid to processing) and longer chain
surfactants facilitating longer term stability (an aid to shelf
life). In some embodiments, shorter chain surfactants have up to
C.sub.10 alkyl (e.g. C.sub.6-C.sub.10 alkyl) as the hydrophobic
portion of the surfactant whilst longer chain surfactants have
C.sub.10 or higher alkyl (e.g. C.sub.10-C.sub.22 alkyl) as the
hydrophobic portion of the surfactant. It is envisaged that
C.sub.10 alkyl surfactants may facilitate processing or facilitate
prolongation of shelf life, or both, depending on the identity of
the other excipients and of the active principle(s). Higher alkyl
may in particular implementations of the invention be
C.sub.11-C.sub.22 or C.sub.12-C.sub.22 alkyl, and in some
embodiments has a length of no greater than C.sub.18.
[0198] Instead of (or as complement to) the surfactant in the
aqueous phase, the invention also contemplates use of
surfactant-like emulsifiers (also known as crystallisation
inhibitors) such as, for example, HPMC (also known as hypromellose)
although their use is generally contemplated in relatively smaller
amounts to avoid high viscosity which may constrain processing
options.
[0199] Other non-ionic surfactants which may be included in the
aqueous phase include poloxamers which are non-ionic triblock
copolymers composed of a central hydrophobic chain of
polyoxypropylene (poly(propylene oxide)) flanked by two hydrophilic
chains of polyoxyethylene (poly(ethylene oxide)). Poloxamers are
available commercially under the trade name Pluronics.TM.. Such
surfactants or similar larger polymeric surfactants are aqueously
soluble and are therefore presented here as optional components of
the aqueous phase. However, they may be used to reduce the amount
of or to replace a higher HLB polymeric component of the oil phase
(see also separate section) such as, for example, polyethoxylated
castor oils (polyethylene glycol ethers) exemplified commercially
as Cremophor.TM.. Diblock, tetrablock, multiblock, etc copolymers
(poloxomers) are also included.
[0200] Another type of polymeric aqueous soluble surfactant which
may be used in a similar way are anionic copolymers based on
methacrylic acid and methyl methacrylate in which the ratio of the
free carboxyl groups to ester groups is approx. 1:1 and with
average molecular weight is approx. 135,000. Such a polymeric
surfactant is available from Degussa under the trade name
EUDRAGIT.RTM. L 100.
[0201] The surfactant included in the aqueous phase is preferably
present within ranges noted above. In the minibead embodiment,
avoidance of excess surfactant is desirable to avoid a "golf ball
effect" whereby minibeads when dried have a plurality of
point-sized dimples in their surface (visible under a microscope).
While not necessarily a major concern, such dimples can lead to
variability in coating if it is desired to apply for example a
polymer coat to the minibeads. Although higher values within the
preferred range generally increase the rate of egress/dissolution
of minibeads, in certain circumstances higher levels of surfactant
included in the composition may cause a counterintuitive drop in
the in vitro dissolution profile including a drop in the total
amount dissolved of the composition according to the invention. The
concentration of surfactant above which the dissolution profile
dropped (or total amount of dissolved composition dropped) may be
approximately 5% by dry weight of the composition, for example when
SDS is selected as the surfactant. In certain embodiments, it is
therefore preferred to have in the aqueous phase a surfactant,
whether non-ionic or ionic, for example anionic e.g. SDS, in an
amount of less than 5% by dry weight of the total composition (for
example, the composition may be in the form of beads or minibeads,
wherein the aqueous phase contains SDS or another surfactant in an
amount of less than 5% by dry weight of the beads/minibeads). In
embodiments of the invention, the composition, e.g. in the form of
beads or minibeads, comprises in the aqueous phase surfactant in an
amount of no more than 5%, no more than 4.5%, no more than 4% or no
more than 3% by dry weight of the beads or minibeads. In one class
of embodiments, the surfactant is in an amount of at least 0.1% by
dry weight of the beads or minibeads. In another class of
embodiments, the surfactant is in an amount of at least 1% by dry
weight of the beads or minibeads. In a further class of
embodiments, the surfactant is in an amount of at least 2% by dry
weight of the beads or minibeads. Higher levels of surfactant in
the aqueous phase (e.g. above 5% by weight of the total
composition) restrict the processing parameters for manufacturing
when certain manufacturing approaches are followed.
[0202] It is noteworthy that surfactants are used in dissolution
testing media when complete dissolution of the composition being
studied is otherwise not achievable. In respect of the amount of
surfactant included in the aqueous phase of the composition of the
present invention as described above, it has been found that such
(small) quantities included in the composition have a much greater
effect than larger quantities included in the dissolution
medium.
[0203] In the case of the minibead embodiment, the present
inventors hypothesise that the local concentration of surfactant in
and around the minibead as it dissolves or disperses is more
effective than an otherwise greater concentration in the medium as
a whole. It is also believed, although the inventors/applicants do
not necessarily intend to be bound by this or other hypotheses
advanced in this text, that the surfactant in the beads assists
egress of active agent from within the polymer coat (if a coat is
afterwards added to the minibeads) and also possibly to shield the
active agent from crystallisation and/or precipitation after
release from the bead.
[0204] In certain embodiments complete or substantially complete
dissolution of steroid in USP/EP/JP etc dissolution apparatus using
standard media can be achieved, using no or only minor amounts of
surfactant in the dissolution medium, by incorporating into the
formulation (e.g. dosage form) one or more surfactants even when
the quantity of surfactant incorporated into the formulation is
much smaller than would have been required in the medium to achieve
a comparable degree of dissolution of a formulation containing no
surfactant. The one or more surfactants may be comprised in the
aqueous phase (the polymer matrix) or the oil phase, or both, and
are in particular comprised in at least the aqueous phase and
optionally also in the oil phase.
[0205] These observations are particularly relevant to the class of
minibead embodiments of the invention, in particular where an
oil-soluble active agent is incorporated in an oil phase or
surfactant (self-assembly structure) phase and the minibead
comprises a surfactant, e.g. in at least the aqueous phase (polymer
matrix). On full dissolution of the composition of the invention in
standard 900-1000 mL dissolution pots using compendial medium, the
concentration of surfactant in an exemplary embodiment would be of
the order of 0.001% i.e. much lower than the amount (around
0.5%-1%) typically added to the dissolution medium. Putting it
another way, very significantly greater amounts of surfactant would
need to be included in this embodiment of the composition of the
invention in order to achieve a fully diluted equivalent
concentration of surfactant typically used in 900-1000 mL
dissolution pots.
[0206] High surfactant concentrations in the dissolution medium can
generate very good in vitro data but which is not necessarily
predictive of in vivo performance (e.g. pharmacokinetic profile).
In contrast, incorporation of (much lower overall quantities of)
surfactant in one embodiment of the minibeads of the invention
produces unexpectedly superior in-vivo performance. The
inventors/applicants hypothesise (without wishing to be bound by
the hypothesis) that surfactant in the dissolution medium is more
playing the role of a dispersing agent (bringing other components
into the dissolution medium) rather than its classical role as an
aid to dissolution and that it is the surfactant included in the
aqueous phase of this embodiment of the composition of the
invention which ensures or enables dissolution. In this setting,
the small amount of surfactant included in the dissolution medium
therefore makes the test more a dispersion test than a dissolution
test and achieves dissolution/dispersion maintenance for the
purposes of compendial methods.
Surfactants for the Hydrophobic Phase
[0207] The formulations mentioned in this specification may
comprise a water-immiscible phase, hydrophobic phase or oil phase
which may comprise the steroid(s). The water-immiscible phase,
where present, may also include surfactant more hydrophobic than
that chosen for the aqueous phase, e.g. a non-ionic surfactant. The
surfactant usually has an HLB value of at least 10 but, in any
event, less than that of the hydrophilic surfactant. The non-ionic
surfactant typically comprises a poly(oxyethylene) group, e.g.
comprises a glycerol polyethylene glycol ricinoleate.
[0208] Examples include polyethoxylated castor oils (polyethylene
glycol ethers) which can be prepared by reacting ethylene oxide
with castor oil. Commercial preparations may also be used as the
surfactant e.g. those commercial preparations which contain minor
components such as, for example, polyethylene glycol esters of
ricinoleic acid, polyethylene glycols and polyethylene glycol
ethers of glycerol. The preferred example is Cremophor by BASF
Corp. also known as Cremophor EL. Alternative or additional
surfactants include phospholipids such as, for example,
phosphatidylcholine. In embodiments of the composition of the
invention which comprise a phospholipid surfactant, the
phospholipid surfactant may be incorporated either in the aqueous
phase or in the oil phase or both. If at least one phospholipid
surfactant is incorporated in each phase, it may be the same
phospholipid surfactant in both phases or different in each.
[0209] The HLB of the surfactant for the water-immiscible phase,
where present, may be from 10-20, e.g. 10-15, and optionally 11-20
(preferably 11-15).
The Dispersed Phase: The Hydrophobic Phase (Oil Phase)
[0210] The hydrophobic phase may comprise an oil. Such oil may
itself be the continuous phase of a water-in-oil emulsion.
[0211] Any pharmaceutically suitable oil may be used to constitute
a hydrophobic phase (oil drops, in this case), optionally in
combination with one or more other oil-miscible and/or oil-soluble
excipients. In terms of dry weight of the composition of the
invention, the oil phase generally comprises a proportion from 10%
to 85%, preferably 15% to 50%, more preferably 20% to 30% or from
35% to 45% e.g. for vaccine formulations. The term "oil" means any
substance that is wholly or partially liquid at ambient temperature
or close-to-ambient temperature e.g. between 10.degree. C. and
40.degree. C. or between 15.degree. C. and 35.degree. C., and which
is hydrophobic but soluble in at least one organic solvent. Oils
include vegetable oils (e.g. neem oil), petrochemical oils, and
volatile essential oils. The hydrophobic phase in particular
comprises a liquid lipid, e.g. a liquid composition comprising
triglycerides and/or diglycerides, for example medium chain
(C.sub.6, C.sub.7, C.sub.8, C.sub.8, C.sub.9, C.sub.10, C.sub.11 or
C.sub.12) diglycerides or triglycerides or combinations
thereof.
[0212] Oils which may be included in the oil phase include
poly-unsaturated fatty acids such as, for example, omega-3 oils for
example eicosapentanoic acid (EPA), docosohexaenoic acid (DHA),
alpha-linoleic acid (ALA), conjugated linoleic acid (CLA).
Preferably ultrapure EPA, DHA or ALA or CLA are used e.g. purity up
to or above 98%. Omega oils may be sourced e.g. from any
appropriate plant e.g. sacha inchi. Such oils may be used singly
e.g. EPA or DHA or ALA or CLA or in any combination. Combinations
of such components including binary, tertiary etc combinations in
any ratio are also contemplated e.g. a binary mixture of EPA and
DHA in a ratio of 1:5 available commercially under the trade name
Epax 6000.
[0213] Oils which may be included in the oil phase are particularly
natural triglyceride-based oils which include olive oil, sesame
oil, coconut oil, palm kernel oil. Oils which are particularly
preferred include saturated coconut and palm kernel oil-derived
caprylic and capric fatty acids and glycerin e.g. as supplied under
the trade name Miglyol.TM. a range of which are available and from
which one or more components of the oil phase of the invention may
be selected including Miglyol.TM. 810, 812 (caprylic/capric
triglyceride); Miglyol.TM. 818: (caprylic/capric/linoleic
triglyceride); Miglyol.TM. 829: (caprylic/capric/succinic
triglyceride; Miglyol.TM. 840: (propylene glycol
dicaprylate/dicaprate). Note that Miglyol.TM. 810/812 differ only
in C.sub.8/C.sub.10-ratio and because of its low C.sub.10-content,
the viscosity and cloud point of Miglyol.TM. 810 are lower. The
Miglyol.TM. range is available commercially from Sasol Industries.
As noted above, oils which may be included in the oil phase need
not necessarily be liquid or fully liquid at room temperature.
[0214] Waxy-type oils are also possible: these are liquid at
manufacturing temperatures but solid or semi-solid at normal
ambient temperatures. The oil phase may therefore be a solid or
semi-solid wax phase at normal ambient temperatures.
[0215] Alternative or additional oils which may be included in the
oil phase according to the invention are medium chain triglyceride
compositions such as for example Labrafac.TM. Lipophile
manufactured by Gattefosse in particular product number WL1349.
Miglyol.TM. 810, 812 are also medium chain triglyceride
compositions. The medium chain triglyceride(s) mentioned herein are
those which comprise one or more triglycerides of at least one
fatty acid selected from fatty acids having 6, 7, 8, 9, 10, 11 or
12 carbon atoms, e.g. C.sub.8-C.sub.10 fatty acids.
[0216] Other possible (alternative or additional) oils include
linoleoyl macrogolglycerides (polyoxylglycerides) such as, for
example, Labrafil (e.g. product number M2125CS by Gattefosse) and
caprylocaproyl macrogolglycerides such as, for example, Labrasol by
Gattefosse.
[0217] In one embodiment of the invention, the oil phase comprises
more than one component. For example, as just mentioned, the oil
phase may comprise a surfactant.
[0218] Within this preferred embodiment, it is further preferred
that the HLB of the oil be in the range 0-10 (optionally 1-8, e.g.
1-6 and sometimes 1-5) and the HLB of the surfactant be in the
range 10-20 and optionally 11-20 (preferably 11-15).
[0219] Particularly preferred oils in the lower HLB category
include medium chain triglycerides, linoleoyl macrogolglycerides
(polyoxylglycerides), caprylocaproyl macrogolglycerides and
caprylic/capric triglyceride. In terms of commercial products,
particularly preferred oils in the lower HLB range are Labrafac.TM.
Lipophile (e.g. 1349 WL), Labrafil, Labrasol, Captex 355 and
Miglyol 810.
[0220] Particularly preferred surfactants in the higher HLB
category include polyethoxylated castor oils (polyethylene glycol
ethers). The preferred commercial product for example is
Cremophor.
[0221] While higher HLB surfactants can be considered surfactants,
the invention also contemplates, additionally or alternatively,
inclusion of any other appropriate (non-ionic or other) surfactant
in the oil phase.
[0222] For certain active principles, particularly
hydrophobic/lipophilic agents such as cyclosporin A for example,
the present inventors/applicants have observed to their surprise
that incorporation into the oil phase of a surfactant of high HLB
and an oil of low HLB in a ratio of 1-4:1 by weight, e.g. 1.2-3.0:1
by weight, preferably 1.5-2.5:1 by weight and most preferably
1.8-2.2:1 by weight (high HLB: low HLB) advantageously stabilizes
the emulsion before and after immobilization of the oil droplets in
the aqueous phase. In this context "stabilize" means in particular
that the embodiment improves dissolution and/or dispersion of the
composition in vitro.
[0223] By "high" HLB in this context is generally intended above
10, preferably from 10-16, e.g. from 12 and 16 or 12 to 14. By
"low" HLB is generally intended below 10, preferably in the range 1
to 4, more preferably 1 to 2.
[0224] The oil phase may also comprise a solvent, miscible with the
oil, for the active principle. The oil phase may therefore comprise
a liquid lipid and a solvent miscible therewith, in which solvent
the water-insoluble active ingredient is soluble. The solvent for
the active principle may be miscible with both the liquid lipid and
with water.
[0225] Examples of suitable solvents are 2-(2-ethoxyethoxy)ethanol
available commercially under trade names Carbitol.TM., Carbitol
cellosolve, Transcutol.TM., Dioxitol.TM., Poly-solv DE.TM., and
Dowanal DE.TM.; or the purer Transcutol.TM. HP (99.9). Transcutol P
or HP, which are available commercially from Gattefosse, are
preferred. Another possible co-solvent is poly(ethylene glycol).
PEGs of molecular weight 190-210 (e.g. PEG 200) or 380-420 (e.g.
PEG 400) are preferred in this embodiment. Suitable PEGs can be
obtained commercially under the name "Carbowax" manufactured by
Union Carbide Corporation although many alternative manufacturers
or suppliers are possible.
[0226] A particularly preferred oil phase according to the
invention is made up of an oil (low HLB), a surfactant (high HLB)
and a solvent for the active principle. The oil may be a liquid
lipid e.g. an MCT composition. For example the following three
commercial products: Transcutol P (as solvent), Miglyol 810 (as
oil) and Cremophor e.g. Cremophor EL (as surfactant) is
particularly preferred. Miglyol 810 has a low HLB and Cremophor has
a high HLB. This particularly preferred oil phase is preferably
used to prepare (and is preferably a component of) a composition of
the invention comprising cyclosporin. In one embodiment, the
composition comprises an oil-soluble or hydrophobic antioxidant
e.g. hydralazine or BHT or carnosic acid or vitamin E.
[0227] The oil phase may also be a water-in-oil (w/o) emulsion so
that the composition of the invention becomes a
water-in-oil-in-water (w/o/w) emulsion.
[0228] The oil phase may include a steroid (i.e. at least one
steroid) and/or one or more other active principles and may also
include one or more volatile or non-volatile solvents, which may be
the same as or different from the solvent or oil phase surfactant
previously mentioned. Such solvents may for example remain in the
composition of the invention following processing e.g. initial
dissolution of the active principle, and have no particular
function in the final composition. Alternatively, such solvents if
present may function to maintain the steroid active principle in a
dissolved state (in solution) within the oil phase or to facilitate
dispersion, egress etc. In other embodiments, the solvent may have
partly or fully evaporated during processing and therefore be
present in only minor quantities if at all. In a related
embodiment, the solvent, particularly when a solvent which is both
oil and water-soluble is used, may be partly or completely present
in the aqueous phase of the composition according to the invention.
An example of such a solvent is ethanol. Another example is
Transcutol which is already mentioned as a solvent.
[0229] It will be appreciated, therefore, that the invention
provides inter alia a bead or minibead comprising a water-soluble
polymer matrix material in which are dispersed droplets of oil, the
composition comprising a steroid and the oil optionally comprising
a combination of a high HLB compound, e.g. a surfactant, and a low
HLB compound, e.g. an oil, and optionally including a solvent.
[0230] The oil droplets in the aqueous phase in its wet state
during manufacture may be small enough (e.g. <100 nm) not to
refract light, hence forming a transparent dispersion. This is
termed a microemulsion, as is well known in the art.
The Dispersed Phase: The Self-Assembly Phase
[0231] As an alternative to an oil or wax phase as described above,
the dispersed phase of the colloidal formulations of the invention
may comprise self-assembly structures, e.g. micelles, vesicles,
liposomes or nanoparticles, or at least the structures which result
from drying aqueous colloids comprising such types of self-assembly
structures. The invention in particular includes formulations in
which the dispersed phase is micellar, i.e. formed of micelles
and/or promicelles. The term "promicelle" refers to a part of a
formulation which will form a micelle upon contact with water, e.g.
gastrointestinal contents.
[0232] A self-assembly structure-forming surfactant is present as
self-assembly structures dispersed within the hydrogel-forming
polymer in a "wet" (not yet dried) composition made as an
intermediate in the manufacturing process described herein. It is
believed also to be present as self-assembly structures in the
dried composition but observability of self-assembly structures in
the dried composition is not a requirement of the invention. It is
mentioned at this point that the presence of a surfactant in
self-assembly structure form does not require that the entire
surfactant content of a composition is in self-assembly structure
form as it is considered more probable that a portion of the
surfactant will be outside the self-assembly structures. Thus in
the "wet" composition, whether the hydrogel-forming polymer is in
the gel state or the sol (liquid) state it may comprise a
micelle-forming surfactant at a concentration above the critical
micelle concentration.
[0233] The diameter of the dispersed self-assembly structures may
be between 0.5 nm and 200 nm, 1 nm and 50 nm, or 5 nm and 25 nm.
The size of the self-assembly structures may be determined by
dynamic light scattering or diffusion NMR techniques known within
the art. Although the size of the self-assembly structures is given
as a diameter this does not imply that the self-assembly structures
must be purely spherical species only that they may possess some
approximately circular dimension.
[0234] The self-assembly structure-forming surfactant may be, or
comprise, a non-ionic surfactant. The surfactant may be a
polyoxyethylated surfactant. The surfactant has a hydrophilic head
which may be a hydrophilic chain, for example a polyoxyethylene
chain or a polyhydroxylated chain.
[0235] The surfactant of course has a hydrophobic part and in
particular a hydrophobic chain. The hydrophobic chain may be a
hydrocarbon chain, for example having at least 6 carbon atoms and
optionally at least 10 carbon atoms, and particularly of at least
12 carbon atoms; some hydrocarbon chains have no more than 22
carbon atoms, for example C.sub.10-C.sub.20, C.sub.12-C.sub.20 or
C.sub.15-C.sub.20 hydrocarbon chains. It may be an alkyl chain,
e.g. having a number of carbon atoms just mentioned. It may be an
alkenyl chain comprising one or more carbon-carbon double bonds,
e.g. having a number of carbon atoms just mentioned. The surfactant
may comprise a hydrocarbon chain, e.g. alkyl chain or alkenyl
chain, that is substituted provided that it maintains a hydrophobic
characteristic. There may for example be one or two substituents,
for example a single substituent, e.g. selected from halogen (e.g.
F or Cl), hydroxy, thiol oxo, nitro, cyano; hydroxy or thiol
substituents may be esterified by for example a fatty acid. One
class of surfactants comprise a hydrocarbon monosubstituted by
hydroxy; optionally, at least a portion of the hydroxy groups of an
aliquot of surfactant, e.g. of the surfactant in a bead, may be
esterified by a fatty acid or mono-hydroxy fatty acid as disclosed
herein or etherified by a fatty alcohol for example having at least
6 carbon atoms and optionally at least 10 carbon atoms, and
particularly of at least 12 carbon atoms; some hydrocarbon chains
have no more than 22 carbon atoms, for example C.sub.10-C.sub.20,
C.sub.12-C.sub.20 or C.sub.15-C.sub.20 fatty alcohols.
[0236] The hydrophobic chain may be part of an esterified fatty
acid R.sup.1--COOH or of an etherified or esterified fatty ether
R.sup.1--COH where R.sup.1 is the hydrophobic chain, e.g. as
mentioned in the preceding paragraph. The ester-forming or, as the
case may be, ether-forming group will typically comprise a
hydrophilic chain.
[0237] As mentioned, the surfactant may have a hydrophilic chain
and may be a non-ionic surfactant, and may satisfy both
requirements. The hydrophilic chain may be a poly(ethyleneglycol),
also known as poly(oxyethylene) or macrogol. The hydrophilic chain
may be of the formula --(O--CH.sub.2--CH.sub.2).sub.n--OR where n
is 5 or 6 to 50 and R is H or alkyl, e.g. ethyl or methyl. The
invention includes implementations in which n is from 6 to 40, e.g.
from 6 to 35. In some embodiments, n is from 6 to 25 and optionally
is from 8 to 25 or from 8 to 15. In other embodiments, n is from 8
to 50 or from 8 to 40, e.g. is from 10 to 50, 10 to 40 or 10 to 35.
In a particular embodiment, n is 15. For all hydrophilic chains of
the formula --(O--CH.sub.2--CH.sub.2).sub.n--OR, in one class of
embodiments R is H.
[0238] The hydrophilic chain may be a polyhydroxylated chain (for
example a C.sub.5-C.sub.20 e.g. C.sub.5-C.sub.10 chain), e.g.
having a hydroxy group on the carbon atoms of the chain, for
example a glucamide.
[0239] The self-assembly structure-forming surfactant may comprise
a combination of a hydrophobic chain as described above and a
hydrophilic chain as described above. It may therefore be, or
comprise, a macrogol ester of a fatty acid as described herein or a
macrogol ether of a fatty alcohol as described herein.
[0240] Self-assembly structure-forming surfactants comprising a
hydrophobic chain and a hydrophilic chain can be selected from the
group consisting of: macrogol esters; macrogol ethers; diblock
copolymers; triblock copolymers; and amphiphilic polymers. In
certain embodiments of the invention any combinations of the group
are included within the invention.
[0241] Examples of macrogol esters which are suitable for use in
the present invention are macrogol esters of fatty acids having at
least 6 carbon atoms and optionally at least 10 carbon atoms, and
particularly of at least 12 carbon atoms; some fatty acids have no
more than 22 carbon atoms, for example C.sub.10-C.sub.20,
C.sub.12-C.sub.20 or C.sub.15-C.sub.10 fatty acids. The fatty acids
may be saturated or unsaturated but are in particular saturated. To
be mentioned are macrogol 25 cetostearyl ether (Cremophor.RTM.
A25); macrogol 6 cetostearyl ether (Cremophor.RTM. A6); macrogol
glycerol ricinoleate 35 (Cremophor.RTM. EL); macrogol-glycerol
hydroxystearate 40 (Cremophor.RTM. RH 40);
macrogol-15-hydroxystearate (Kolliphor.RTM. HS 15, previously known
as Solutol.RTM. HS 15). Examples of macrogol ethers which are
suitable for use in the present invention are macrogol ethers of
fatty alcohols having at least 6 carbon atoms and optionally at
least 10 carbon atoms, and particularly of at least 12 carbon
atoms; some fatty alcohols have no more than 22 carbon atoms, for
example C.sub.10-C.sub.30, C.sub.12-C.sub.20 or C.sub.15-C.sub.20
fatty alcohols. The fatty alcohols may be saturated or unsaturated
but are in one embodiment saturated.
[0242] Examples of amphiphilic polymers which are suitable for use
in the present invention are: alkyl glucamides; fatty alcohol
poly(ethoxyl)ates also known as polyethoxylated alkyl ethers;
poly(ethoxyl)ated fatty acid esters (Myrj or Kolliphor.RTM. HS 15);
fatty amide polyethoxylate; fatty amine ethoxylate; alkylphenol
ethoxylate; polyethoxylated sorbitan esters (polysorbates);
polyethoxylated glycerides; or poly-glycerol esters.
[0243] Examples of copolymers, which are suitable for use in the
present invention are: pluronics(poloxamers);
polyvinylpyrollidone-polyvinylacetate (Plasdone S630); aminoalkyl
methacrylate copolymer (Eudragit EPO); methacrylic acid--methyl
methacrylate copolymer (Eudragit S100, L100); polycaprolactone-PEG;
polycaprolactone-methoxy--PEG; poly(aspartic acid)-PEG;
poly(benzyl-L-glutamate)-PEG; poly(D,L-lactide)methoxy-PEG;
poly(benzyl-L-aspartate-PEG; or poly(L-lysine)-PEG
[0244] In a preferred embodiment the self-assembly
structure-forming surfactant is a macrogol ester, more preferably a
macrogol ester that conforms to the European Pharmacopoeia
monograph number 2052 macrogol-15-hydroxystearate, such as
Kolliphor.RTM. HS 15 marketed by BASF.
[0245] Suitable surfactants comprise those which during manufacture
combine with the aqueous phase (including hydrogel-forming polymer)
in an amount above their CMC to form a clear liquid. Kolliphor.RTM.
HS 15 is such a surfactant.
[0246] In certain embodiments the weight ratio of the self-assembly
structure-forming surfactant to the antigen is from 10:1 to 100:1,
optionally from 50:1 to 100:1. In some embodiments, the ratio is
from 80:1 to 90:1. In particular embodiments, the ratio is from
50:1 to 60:1.
[0247] In particular embodiments, the compositions of the invention
comprise a combination of self-assembly structure-forming
compounds. Such a combination of self-assembly structure-forming
compounds may consist of two or more surfactants as mentioned in
the preceding section of this specification. Alternatively, a
surfactant may be combined with one or more other compounds at
least potentially able to form self-assembly structures with the
surfactant, optionally selected from cationic lipids and
glycolipids, amongst others. As an additional option, a composition
may comprise a plurality of surfactants as mentioned in the
preceding section of this specification and one or more other
compounds at least potentially able to form self-assembly
structures with the surfactant, optionally selected from cationic
lipids and glycolipids, amongst others.
[0248] The invention therefore includes compositions as described
herein which comprise: [0249] two or more self-assembly
structure-forming surfactants, e.g. two or more surfactants having
a hydrophobic chain and a hydrophilic chain [0250] a compound, e.g.
a single compound or two or more compounds, selected from cationic
lipids and glycolipids [0251] two or more self-assembly
structure-forming surfactants and a compound, e.g. a single
compound or two or more compounds, selected from cationic lipids
and glycolipids
The Aqueous Phase
[0252] The principal component of the aqueous phase of the dried
colloidal formulations according to the invention (preferably
between 20% and 70%, more preferably between 30% and 60%, still
more preferably between 35% and 55%, by dry weight thereof) is a
water-soluble polymer matrix material although other components may
also be included as described below. The inclusion of too little of
the water-soluble polymer matrix material can for certain active
principles lead to non-incorporation or leaching of the active out
of the composition, particularly when in the form of minibeads. For
certain embodiments, for example micellar compositions, e.g.
comprising Kolliphor.RTM. HS 15, or those comprising a retardant
(see below), it is preferred that the water-soluble polymer matrix
material constitute from 55% and 65% of the dry weight of the
composition.
[0253] While mixtures of water-soluble polymer matrix materials are
contemplated by the invention, the matrix material may be
substantially a single material or type of material among those
described herein. Where the matrix material is a single type of
material, that type may be thermotropic hydrogel-forming polymers;
for example, a combination of such polymers may be used. However,
mixtures may be preferred to achieve certain performance
characteristics. Thus it may be desired to incorporate certain
controlled release or retarding substances (retardants) into the
water-soluble polymer matrix. In certain embodiments, such
incorporation permits a coat (or coating) to be dispensed with. In
other embodiments where a controlled release or retarding agent is
included into the water-soluble polymer matrix, a coat (or coating)
may be present and desirable. For example, incorporation of a
retarding agent which is insoluble in acid milieu (such as the
stomach) is selected to prevent or retard release in the stomach
and a coating may not be needed i.e. the composition may be free of
a coat/coating. Alternatively, incorporation of a retarding agent
which is soluble in acid media may be selected to retard release in
the intestine distal to the stomach. Again a coating may not be
needed i.e. the composition may be free of a coat/coating. However,
a composition according to the invention which incorporates a
retarding agent soluble in acid media may optionally be coated e.g.
with an acid-resistant polymer to achieve particular advantage.
Such a composition is protected from (complete) gastric release (or
gastric release is retarded) owing to the effect of the
acid-resistant polymer coat. Distal to the stomach, following loss
of the coat, the acid-soluble agent retards release because the
milieu of the small and large intestine is no longer acid.
Retarding or controlled release agents insoluble in acid milieu
include polymers whose solubility is pH-dependent i.e. soluble at
higher pH. Such polymers are described in detail in the section
below entitled "Coating" and such polymers may be used either as
coats/coatings or as retarding agents or controlled release agents
incorporated into the water-soluble polymer matrix. An example of a
suitable retarding agent mentioned in the section below entitled
"Coating" is HPMCP (hydroxy-propyl-methyl-cellulose-phthalate also
known as hypromellose phthalate) which is used to prevent release
in the gastric environment since it is soluble above pH 5.5--see
that section for other examples of polymers soluble in non-acid
(basic) media. HPMCP may also be used as a pore-former. Retarding
or controlled release agents soluble in acid milieu include
polymers whose solubility is pH-dependent i.e. soluble at lower pH.
Such polymers include cationic polymers such as for example
copolymers based on dimethylaminoethyl methacrylate, butyl
methacrylate, and methyl methacrylate. An example of such a
cationic co-polymer which may be used according to the invention is
Eudragit E PO commercially available from Evonik Industries.
[0254] In one embodiment, the water-soluble polymer matrix material
may be of one or more of (e.g. two of) those selected from gelatin,
agar, a polyethylene glycol, starch, casein, chitosan, soya bean
protein, safflower protein, alginates, gellan gum, carrageenan,
xanthan gum, phthalated gelatin, succinated gelatin,
cellulosephthalateacetate, oleoresin, polyvinylacetate,
hydroxypropylmethyl cellulose, polymerisates of acrylic or
methacrylic esters and polyvinylacetate-phthalate and any
derivative of any of the foregoing. If a single polymer material is
used, it may be gelatin. If a mixture of polymer materials is used,
the mixture may comprise gelatine, e.g. in combination with one or
more members of the list earlier in this paragraph. In specific
embodiments binary or tertiary etc combinations of any of the above
substances are foreseen. An advantage of combining certain
water-soluble polymers, e.g. gelatin and agar, to form the matrix
is that it allows for a reduction in the total amount of
water-soluble polymer employed. This may have cost advantages or
may allow greater loading of other materials such as, for example,
one or more active principles. Inclusion of (addition of) a second
water-soluble polymer to form the matrix may also give more
strength to the composition of the invention e.g. beads.
[0255] In a preferred embodiment, the polymer matrix material is a
hydrocolloid i.e. a colloid system wherein the colloid particles
are dispersed in water and depending on the quantity of water
available can take on different states, e.g., gel or sol (liquid).
It is preferred to use reversible hydrocolloids (e.g. agar, gelatin
etc) as opposed to irreversible (single-state) hydrocolloids.
Thermotropic hydrocolloids (also known as thermoreversable
hydrocolloids) can exist in a gel and sol state, and alternate
between states with the addition or elimination of heat. Gelatin is
a thermo-reversible, rehydratable colloid and is particularly
preferred. Gelatin derivatives such as, for example, succinated or
phthalated gelatins are also contemplated. Hydrocolloids which may
be used according to the invention include those derived from
natural sources such as, for example, carrageenan (extracted from
seaweed), gelatin (extracted from bovine, porcine, fish or vegetal
sources), agar (from seaweed) and pectin (extracted from citrus
peel, apple and other fruits). A non-animal based hydrocolloid may
be preferred for certain applications e.g. administration to
vegetarians or to individuals not wishing to ingest animal products
for religious or health reasons. In relation to the use of
carrageenan, reference is made to US patent application
2006/0029660 A1 (Fonkwe et al), the entirety of which is
incorporated herein by reference.
[0256] The water-soluble polymer may therefore be gelatin. The
water-soluble polymer may comprise gelatin
[0257] The immobilized aqueous phase of the composition according
to one embodiment of the invention is preferably a gel i.e. a
substantially dilute crosslinked system, which exhibits no flow
when in the steady-state. The internal network structure of the
solidified aqueous phase may result from physical or chemical
bonds, as well as crystallites or other junctions that remain
intact within an extending fluid e.g. water.
[0258] In an alternative preferred embodiment, the polymer matrix
is a non-hydrocolloid gum. Examples are the cross-linked salts of
alginic acid. For example, aqueous solutions of sodium alginate
gums extracted from the walls of brown algae have the well known
property of gelling when exposed to di- and trivalent cations. A
typical divalent cation is calcium, often in the form of aqueous
calcium chloride solution. It is preferred in this embodiment that
the cross-linking or gelling have arisen through reaction with such
a multivalent cation, particularly calcium.
[0259] In an alternative preferred embodiment, the polymer matrix
is chitosan which can exist in the form of biogels with or without
additives as described e.g. in U.S. Pat. No. 4,659,700 (Johnson
& Johnson); by Kumar Majeti N. V. Ravi in Reactive and
Functional Polymers, 46, 1, 2000; and by Paul et al. in ST. P.
Pharma Science, 10, 5, 2000 the entirety of all 3 of which is
incorporated herein by reference. Chitosan derivatives e.g.
thiolated entities are also contemplated.
[0260] As regards gelatin, reference is hereby made to "bloom
strength", a measure of the strength of a gel or gelatin developed
in 1925 by O. T. Bloom. The test determines the weight (in grams)
needed by a probe (normally with a diameter of 0.5 inch) to deflect
the surface of the gel 4 mm without breaking it. The result is
expressed in Bloom (grades) and usually ranges between 30 and 300
Bloom. To perform the Bloom test on gelatin, a 6.67% gelatin
solution is kept for 17-18 hours at 10.degree. C. prior to being
tested.
[0261] Where the polymer matrix comprises gelatin, e.g. is gelatin,
it is preferred to use gelatin with bloom strength between 200 and
300, preferably between 210 and 280.
[0262] Where the polymer matrix comprises gelatin, e.g. is gelatin,
the gelatin may be obtained from a variety of sources. For example,
it can be obtained by the partial hydrolysis of collagenous
material, such as the skin, white connective tissues, or bones of
animals. Type A gelatin is derived mainly from porcine skins by
acid processing, and exhibits an isoelectric point between pH 7 and
pH 9, while Type B gelatin is derived from alkaline processing of
bones and animal (bovine) skins and exhibits an isoelectric point
between pH 4.7 and pH 5.2. Type A gelatin is somewhat preferred.
Gelatin for use in the invention may also be derived from the skin
of cold water fish. Blends of Type A and Type B gelatins can be
used in the invention to obtain a gelatin with the requisite
viscosity and bloom strength characteristics for minibead
manufacture.
[0263] Commercially gelatin can be obtained from the Sigma Chemical
Company, St. Louis, Mo. USA or from Nitta
(http://www.nitta-gelatin.com).
[0264] Lower temperature gelatin (or gelatin derivatives or
mixtures of gelatins with melting point reducers) or other polymer
matrices able to be solidified at lower temperatures (e.g. sodium
alginate described above) are preferred for example when the active
principle to be incorporated in the composition of the invention is
temperature-labile or whose activity may be affected by exposure to
higher temperatures.
[0265] Where the polymer matrix comprises gelatin, e.g. is gelatin,
the starting gelatin material is preferably modified before
manufacture to produce "soft gelatin" by the addition of a
plasticizer or softener to the gelatin to adjust the hardness of
the composition of the invention. The addition of plasticizer
achieves enhanced softness and flexibility as may be desirable to
optimise dissolution and/or further processing such as, for
example, coating. Useful plasticizers of the present invention
include glycerin (1,2,3-propanetriol), D-sorbitol (D-glucitol),
sorbitol BP (a non-crystallizing sorbitol solution) or an aqueous
solution of D-sorbitol and sorbitans (e.g. Andidriborb 85/70).
Other or similar low molecular weight polyols are also
contemplated. Polyethylene glycol may also be used although this is
less preferred and indeed particularly preferred compositions of
the invention are free or substantially free of PEG or derivatives
thereof. Glycerin and D-sorbitol may be obtained from the Sigma
Chemical Company, St. Louis, Mo. USA or Roquette, France.
[0266] As noted above, some constituents of the present invention
may play more than one role. For example when one of the active
principles (see below) is ibuprofen, it may also act as a
plasticiser owing to its particular physico-chemical properties.
Choice of ibuprofen has particular advantages in relation to higher
loading as "conventional" plasticiser, for example dibutyl sebacate
or DBS, may be reduced in quantity. Alternatively it is
contemplated that the surfactants discussed above may be selected
for their plasticiser characteristics to achieve particular
advantage.
[0267] Softeners, if utilized, can be ideally incorporated in a
proportion rising to 30%, preferably up to 20% and more preferably
up to 10% by dry weight of the composition of the invention, even
more preferably between 3 and 8%, and most preferably between 4%
and 6%.
[0268] As noted in more detail above in the section on surfactants,
it is preferred to include one or more surfactants in the aqueous
phase. Certain surfactants may also act as plasticisers or
softeners or vice versa.
[0269] Although not essential, the aqueous phase may also
optionally contain a disintegrant where it is particularly desired
to enhance the rate of disintegration of the composition of the
invention.
[0270] Examples of disintegrants which may be included are alginic
acid, croscarmellose sodium, crospovidone, low-substituted
hydroxypropyl cellulose and sodium starch glycolate.
[0271] A crystallisation inhibitor (e.g. approximately 1% by dry
weight of the composition) may also be included in the composition
of the invention, preferably in the aqueous phase. An example is
hydroxy propyl/methyl cellulose (HMC or HPMC, hypromellose etc)
which may play other roles such as, for example, emulsifier (see
above). In addition, the aqueous phase may include some or all of a
solvent used during processing to dissolve, or facilitate
dissolution of, an active principle e.g. an active principle
comprised in the oil phase. An example is ethanol (see discussion
above on use of solvents in oil phase).
[0272] The invention includes compositions comprising a solid phase
comprising a water-soluble polymer matrix material and an oil phase
dispersed in the solid phase.
Shape, Size and Geometry of Dried Colloidal Formulations
[0273] The dried colloidal compositions (i.e. those obtainable by
drying a colloid can be formed into a limitless number of shapes
and sizes. In the section below describing the process for making
the composition, various methods are given including pouring or
introducing a fluid emulsion into a mould where it hardens or can
be caused to harden. Thus the composition can be created in
whichever form is desired by creating an appropriate mould (e.g. in
the shape of a disc, pill or tablet). However, it is not essential
to use a mould. For example, the composition may be in the form of
a sheet e.g. resulting from pouring a fluid emulsion onto a flat
surface where it hardens or can be caused to harden.
[0274] Alternatively, the composition may be in the form of spheres
or spherical-like shapes made as described below. Preferably, the
composition of the invention is in the form of spherical, seamless
beads, especially minibeads. (It will be understood that the terms
"sphere" and "spherical" as applied to beads/minibeads do not refer
to precise geometric spheres but to shapes which, to the human eye,
approximate to spheres). The absence of seams on the minibead
surface is an advantage e.g. in further processing, for example
coating, since it allows more consistent coating, flowability etc.
The absence of seams on the minibeads also enhances consistency of
dissolution of the minibeads.
[0275] The preferred size or diameter range of minibeads according
to the invention can be chosen to avoid retention in the stomach
upon oral administration of the minibeads. Larger dosage forms are
retained for variable periods in the stomach and pass the pyloric
sphincter only with food whereas smaller particles pass the pylorus
independently of food. Selection of the appropriate size range (see
below) thus makes the prediction of therapeutic effect post-dosing
more accurate. Compared to a single large monolithic oral format
such as, for example, a traditional compressed tablet, a plurality
of minibeads released into the GI tract (as foreseen by the present
invention) permits greater intestinal lumen dispersion so enhancing
absorption via exposure to greater epithelial area, prevents
irritation (e.g. as otherwise seen with NSAIDs) and achieves
greater topical coating (e.g. as may be desired for local drug
effect in certain parts of the GI tract for example the colon).
Reduction of residence time in the ileo-caecal junction is another
advantage.
[0276] The dried colloidal composition is preferably monolithic
meaning internally (i.e. cross-sectionally) homogeneous. This is
particularly preferred for the minibead embodiment.
[0277] The minibeads mentioned herein generally range in diameter
from 0.5 mm to 10 mm with the upper limit preferably 5 mm, e.g. 3
mm or 2.5 mm. A particularly convenient upper limit is 2 mm or 1.7
mm. The lower limit can preferably be 1 mm, e.g. 1.2 mm, more
preferably from 1.3 mm, most preferably from 1.4 mm. In one
embodiment the diameter is from 0.5 to 2.5 mm, for example from 1
mm to 3 mm, 1 mm to 2 mm, 1.2 mm to 3 mm or 1.2 mm to 2 mm. The
minibeads may have a diameter of no more than 2.5 mm, irrespective
of their minimum size. The minibeads may have a diameter of no more
than 2 mm, irrespective of their minimum size.
[0278] A minibead as described herein may have an aspect ratio of
no more than 1.5, e.g. of no more than 1.3, for example of no more
than 1.2 and, in particular, of from 1.1 to 1.5, 1.1 to 1.3 or, 1.1
to 1.2. A population of minibeads as described herein, e.g. at
least 10 minibeads, may have an average aspect ratio of no more
than 1.5, e.g. of no more than 1.3, for example of no more than 1.2
and, in particular, of from 1 to 1.5, 1 to 1.3 or 1 to 1.2. The
aspect ratios mentioned in this paragraph optionally apply to
coated minibeads and optionally apply to uncoated minibeads.
Average aspect ratio is suitably determined for a population of
beads, e.g. at least 10 beads, using a particle size analyser, for
example an Eyecon.TM. particle characteriser of Innopharma Labs,
Dublin 18, Ireland.
[0279] Minibead size (diameter) may be measured by any suitable
technique, for example microscopy, sieving, sedimentation, optical
sensing zone method, electrical sensing zone method or laser light
scattering. Minibead size is in particular measured by optical
microscopy or sieving.
[0280] In embodiments, the minibeads are monodisperse. In other
embodiments, the minibeads are not monodisperse. By "monodisperse"
is meant that for a plurality of minibeads (e. g. at least 100,
more preferably at least 1000) the minibeads have a coefficient of
variation (CV) of their diameters of 35% or less, optionally 25% or
less, for example 15% or less, such as e.g. of 10% or less and
optionally of 8% or less, e.g. 5% or less. A particular class of
polymer minibeads has a CV of 25% or less. CV when referred to in
this specification is defined as 100 times (standard deviation)
divided by average where "average" is mean particle diameter and
standard deviation is standard deviation in particle size. Such a
determination of CV is performable using a sieve.
[0281] The minibeads may have a CV of 35% and a mean diameter of 1
mm to 2 mm, e.g. 1.5 mm. The minibeads may have a CV of 20% and a
mean diameter of 1 mm to 2 mm, e.g. 1.5 mm, e.g. a CV of 10% and a
mean diameter of 1 mm to 2 mm, e.g. 1.5 mm. In one class of
embodiments, 90% of beads have a diameter of from 0.5 mm to 2.5 mm,
e.g. of from 1 mm to 2 mm.
[0282] Another possible form of the composition is as hemispherical
beads two of which may optionally be joined at the flat face to
create a single minibead with two distinct halves, each having a
distinct composition, if that is desired, e.g. each containing
different active principles or the same active principles but
different excipients e.g. to achieve differing permeability,
solubilization or release profiles as between the two
hemispheres.
[0283] The embodiment in which the composition takes the form of
minibeads can be further developed to create a larger mass of
minibeads e.g. via compression (with appropriate oil or
powder-based binder and/or filler known to persons skilled in the
art of pharmaceutical formulation) and with the option of including
additional quantities of the same active ingredient as in the
composition of the invention or a different active ingredient. For
example, the composition of the invention may take the form of
beads which comprise an active agent or combination of active
agents as disclosed herein and the binder or filler comprises an
active agent mentioned previously herein in the context of
combination therapy with a steroid. A compressed mass of minibeads
may disintegrate at a different rate in different conditions than a
unitary moulded form of the same shape. The larger (e.g.
compressed) mass may itself take a variety of shapes including pill
shapes, tablet shapes, capsule shapes etc. A particular problem
which this version of the minibead embodiment solves is the "dead
space" (above the settled particulate contents) and/or "void space"
(between the particulate content elements) typically found in hard
gel capsules filled with powders or pellets. In such pellet- or
powder-filled capsules with dead/void space, a patient is required
to swallow a larger capsule than would be necessary if the capsules
contained no such dead space. The minibeads of this embodiment of
the invention may readily be compressed into a capsule to adopt the
inner form of whichever capsule or shell may be desired leaving
much reduced, e.g. essentially no, dead/void space. Alternatively
the dead or void space can be used to advantage by suspending
minibeads in a vehicle such as, for example, an oil which may be
inert or may have functional properties such as, for example,
permeability enhancement or enhanced dissolution or may comprise an
active ingredient being the same or different from any active
ingredients in the bead. For example, hard gelatin capsules may be
filled with a liquid medium combined with uncoated and/or coated
beads. The liquid medium may be or comprise one or more of the oil
phase constituents described herein or it may be one or more
surfactants. Particularly preferred but non-limiting examples are
corn oil and the commercial products known as Span 85, Labrafac,
Transcutol P and Tween 80.
[0284] Another possible form of the dried colloidal compositions is
as a capsule in which the core of the composition is a solid (e.g.
gastro-retentive float material such as, for example, bicarbonate
salts) or a fluid (a gas or a liquid). If the core is a liquid, it
may contain an active principle and/or excipients which may be the
same or different from those described above. Like the
hemispherical beads described above, such capsules may have two
halves of different constitution and sealed hermetically to retain
the internal fluid. An internal layer e.g. internal film layer of
non-aqueous material on the inner face of the sphere, may be
included if it is desired that the core be an aqueous liquid such
that the internal layer prevents the aqueous core from coming into
contact with the inner surface of the capsule. With or without an
intermediate layer, the core may be a variant of the dried
colloidal compositions so that the composition of the invention, in
the minibead embodiment, comprises a core made from a first
composition according to the invention and a capsule made from a
second composition according to the invention.
[0285] The minibead embodiment of the invention, while by itself
offering a range of solutions to the issues identified above, may
also be used as a starting point for creation of further e.g.
pharmaceutical or forms for example by using the minibead as a seed
on which additional layers of material can be applied as is well
known to a person skilled in the art e.g. of pharmaceutical
science. The material of the additional layers may comprise the
same or different active principle and/or the same or different
excipients as are described in this document. Such variants allow
differential release of the same or different active principles and
facilitate inclusion of multiple fixed-dose combination products as
for example discussed in connection with the popularly termed
"polypill" which denotes a single pill comprising more than one
active principle in a fixed dose combination.
[0286] The formulations, whether or not dried colloidal
formulations, may have a coat of additional material on its outer
surface. This coat may be applied in a number of ways, including
drug layering, as described more particularly in the section below
entitled "coating". In one such embodiment, the formulation
comprises an acid within the formulation, for example within a
bead, e.g. included within the water-soluble polymer matrix or as a
liquid core in minibead format and bicarbonate applied as a coat
e.g. by drug layering. If the formulation, e.g. minibead, has a
polymeric coat, e.g. to control release into the colon, the
bicarbonate may optionally or additionally be included in or be
absent from the coating polymer. This composition is intended to
release carbon dioxide in the GI tract e.g. to reduce pain or to
reduce inflammation. The formulation may comprise an acid to
enhance the solubility of active principles of various pKa (acid
dissociation constant) in the small intestine or colon.
Alternatively, the formulation may comprise a base to enhance the
solubility of active principles of various pKa in the stomach.
Other Characteristics of Dried Colloidal Formulations
[0287] The colloidal compositions, in certain embodiments,
comprises one or more elements, components, excipients, structural
features, functional features or other aspects of the prior art
described above.
[0288] To summarise a limited number of embodiments of the
invention, the composition as described above and elsewhere herein
may additionally be one or more of the following: substantially
water-free, in a gel state, in a solid state, undissolved,
non-powdered, formed, shaped, and not in solution.
[0289] Unless geometrically designed to comprise inner aqueous
compartments (e.g. w/o/w format or capsular format with liquid
core), it is desirable that the colloidal formulations of the
invention are essentially or substantially dry, e.g. contains less
than 5%, preferably less than 1% of free water by weight. Minibeads
are preferably homogeneous although processing conditions may be
varied (see below) to achieve for example heterogeneity such as,
for example, a harder skin and softer core with less than complete
immobilization of oil droplets towards the core as opposed to the
surface of the bead. Larger (e.g. non-beaded) forms or shapes of
the composition according to the invention may particularly be
engineered to embody such heterogeneity.
[0290] The low free-water content is a distinguishing feature of
certain embodiments of the colloidal compositions i.e. dried
colloidal compositions. The free-water content can be measured
using thermogravimetic analysis (TGA), for example with
commercially available instrumentation, e.g. using a TGA Q 500 of
TA Q series instrument. TGA measures changes in weight in relation
to a change in temperature. For example, a TGA method can comprise
a temperature scan, e.g. from 20 to 400.degree. C. at 20.degree. C.
per minute, where the moisture content is obtained from the sample
weight loss at about 100 degrees Celsius.
[0291] In one embodiment, the dispersed phase, e.g. oil droplets is
homogeneously dispersed in the solidified aqueous phase (or in some
embodiments the water-soluble polymer matrix material) with
substantial absence of coalescence between adjacent oil droplets.
Thus the colloid is preferably maintained during solidification.
Coalescence of neighbouring oil droplets or self-assembly
structures, preferably only occurs, if at all, on rehydration of
the composition of the invention.
[0292] Depending on process parameters, oil droplet size can vary
broadly e.g. from 10 nm to 10 .mu.m (diameter). However, the
inventors/applicants have found that it is beneficial to maintain
droplet size in the range from 100 nm to 1 .mu.m, e.g. from 300-700
nm. The term "emulsion" therefore includes microemulsions and
nanoemulsions.
[0293] The colloidal compositions may comprise multiple drops or
droplets of water-immiscible liquid (or solid or semi-solid) within
a moulded or shaped form e.g. a minibead which might typically
contain many hundreds or thousands of droplets or self-assembly
structures as distinct from a powder which generally derives from
micron-sized particles incorporating a single or a small number of
oil droplets often following coalescence of smaller droplets during
spray-drying. While powder embodiments are not excluded, the
composition of the invention, if particulate, preferably comprises
particles larger than powder particles such that the composition is
in a non-powdered form.
[0294] Where the formulation is in the form of minibeads, a
plurality of minibeads may be presented in a single format e.g.
contained in a single capsule, e.g. hard gel capsule, which
releases the minibeads e.g. in the stomach. Alternatively the
minibeads may be presented in a sachet or other container which
permits the minibeads to be sprinkled onto food or into a drink or
to be administered via a feeding tube for example a naso-gastric
tube or a duodenal feeding tube. Alternatively, the minibeads may
be administered as a tablet for example if a plurality of minibeads
are compressed into a single tablet as described elsewhere herein.
Alternatively, the minibeads may be filled e.g. compressed into a
specialist bottle cap or otherwise fill a space in a specialised
bottle cap or other element of a sealed container (or container to
be sealed) such that e.g. on twisting the bottle cap, the minibeads
are released into a fluid or other contents of the bottle or vial
such that the beads are dispersed (or dissolve) with or without
agitation in such contents. An example is the Smart Delivery Cap
manufactured by Humana Pharma International (HPI) S.p.A., Milan,
Italy. A related or similar approach is also contemplated for e.g.
timed release of mini-capsules into a reactor, feeding environment
e.g. tank, incubator etc.
[0295] The minibeads so-presented may be of a single type (or
population) or may be of multiple types (or populations) differing
between populations in relation to one or more features described
herein e.g. different API or different excipients or different
physical geometry, coated, multiply coated, uncoated etc.
[0296] In one embodiment, the invention allows for minibeads having
immediate release (IR) characteristics e.g. bearing no coat,
enteric-only coat or coat designed to prevent release and/or
dissolution of the bead only for a limited time or lacking a
retardant in the aqueous phase. In another embodiment, the
invention allows for minibeads having delayed or sustained release
(SR) characteristics e.g. bearing a coat (or more than one coat) as
described in more detail elsewhere herein, particularly in the
section entitled "coating". The invention also provides for an
embodiment in which immediate release minibeads are produced in
combination with a Sustained Release or Controlled Release (CR)
minibeads in varying ratios of IR:SR/CR. The immediate release
minibeads can be combined with a Sustained or Controlled release
minibead component in the following ratios (w/w by potency) e.g.
10% Immediate Release (IR)+90% Sustained (SR)/Controlled Release
(CR) minibeads; 20% IR+80% SR/CR; 30% IR+70% SR/CR; 40% IR+60%
SR/CR and 50% IR+50% SR/CR.
Other Active Excipients
[0297] The heading of this section is for convenience only and does
not imply strict categorisation. For example, a category, substance
or active principle described within this "other active excipients"
may also be considered to fall within another section or category
in this patent application. One (non-limiting) example is the group
of substances known as phospholipids which, according to the
invention may be excipients, permeability enhancers or active
principles (e.g. phosphatidylcholine which is useful for instance
in the treatment of inflammatory bowel disease).
[0298] However, in general terms, the invention foresees optional
incorporation into the formulation of one or more of the following
substances or categories of substances in addition to the primary
active agent. For example, the composition may contain a protectant
such as, for example, a proteolytic enzyme inhibitor or a protector
against acid degradation or both (e.g. an alkali for example sodium
hydroxide); an adhesive entity such as, for example, a muco- or
bio-adhesive; excipients to maximize solubility of active
pharmaceutical compound(s); an antigen(s) and/or an adjuvant(s) to
induce an intestinal mucosal or a systemic immune response.
[0299] The composition may further comprise excipients to enhance
the therapeutic potential of active agents in the ileum and colon
including, but not limited to absorption limiters, essential oils
such as, for example, omega 3 oils, natural plant extracts such as,
for example, neem, ion-exchange resins, bacteria degradable
conjugation linkers such as, for example, azo bonds,
polysaccharides such as, for example, amylose, guar gum, pectin,
chitosan, inulin, cyclodextrins, chondroitin sulphate, dextrans,
guar gum and locust bean gum, nuclear factor kappa B inhibitors,
acids such as, for example, fumeric acid, citric acid and others,
as well as modifications thereof.
[0300] The composition may further comprise excipients to reduce
systemic side effects associated with absorption in the small
intestine including, but not limited to, antioxidants, such as, for
example, curcuminoids, flavanoids or more specifically including
curcumin, beta-carotene, .alpha.-tocopherol, ascorbate or
lazaroid.
[0301] The composition may further or separately comprise
antioxidants (such as, for example, ascorbic acid or BHT--butyl
hydroxy toluene) taste-masking or photosensitive components or
photoprotective components. Antioxidants may be incorporated in the
aqueous phase (e.g. hydrophilic antioxidants) or in the oil phase
(e.g. hydrophobic antioxidants such as, for example, vitamin E) for
example up to 1% by weight, preferably between 0.01 and 0.50% by
weight, more preferably between 0.10 to 0.20% by weight.
Process for Making Colloidal Formulations
[0302] The reader is notified that it is important to refer to this
section in relation to the Examples.
[0303] A basic method for making colloidal formulations is to mix a
fluid form (preferably a solution) of the polymer (or mixture of
polymers) chosen to be the water-soluble polymer matrix material
(e.g. gelatin, gum, alginate etc as described more generally
elsewhere herein and in any event optionally in admixture with
other components described above) with a dispersed phase material,
e.g. a surfactant phase or an oil phase, to form a homogeneous
fluid colloid e.g. an emulsion. Taking account of the final
composition required (as described elsewhere herein), the dispersed
phase and the aqueous phase may be mixed in a proportion in the
range 1:6-10, particularly approximately 1:7 or 1:8 for an oily
disperse phase or 1:1 to 1:4 for a surfactant (micellar) dispersed
phase. In general, only gentle stirring of the components is
required using a magnetic or mechanical system e.g. overhead
stirrer as would be familiar to a person skilled in the art to
achieve emulsification. Continuous stirring is preferred. Any
appropriate laboratory stirring apparatus or industrial scale mixer
may be utilized for this purpose for example the Magnetic Stirrer
(manufactured by Stuart) or Overhead Stirrer (by KNF or Fisher). It
is preferred to set up the equipment in such a way as to minimise
evaporation of contents such as, for example, water. In one
embodiment of the process of the invention, it is preferred to
utilise a closed system for stirring in order to achieve this
aim.
[0304] Where the polymer matrix is substantially constituted by
gelatin with the addition of sorbitol, the aqueous phase of polymer
matrix is prepared by adding the appropriate quantities of sorbitol
(and surfactant and/or active agent, if desired) to water, heating
to approximately 60-75.degree. C. until in solution and then adding
gelatin although the precise order and timing of addition is not
critical. A typical "gelatin solution" comprises 15-25% (preferably
17-18%) gelatin; 75%-85% (preferably 77-82%) of water plus from
1-5% (preferably 1.5 to 3%) sorbitol.
[0305] The choice of temperature at which the colloid is formed
depends however on various factors include the temperature lability
of the active pharmaceutical ingredient and the amount of
plasticiser included in the gelatin, the type of gelatin, as well
as other factors. Generally however, the gelatin solution
(especially in the case of standard or normal gelatin) is
maintained at 60.degree. C.-70.degree. C. to maintain it in a fluid
state.
[0306] The processing temperature can be reduced to a desirable
target temperature e.g. 37.degree. C. by use of lower melting-point
gelatin (or gelatin derivatives or mixtures of gelatins with
melting point reducers) or other polymer matrix material such as,
for example, sodium alginate for example when the active principle
to be incorporated in the composition of the invention is
temperature-labile. Alternatively, temperature-labile active
principles may be processed at higher temperatures by using
appropriate apparatus or machinery which limits the time during
which the temperature-labile active principle is in contact with
the higher temperature medium. For example, if gelatin droplets are
being formed by machine extrusion and immediately cooled e.g. in a
cooling bath, additional appropriate inlet tubing can be used to
introduce temperature-sensitive active principle into the fluid
gelatin solution (and the mixture can be immediately homogenized)
very shortly before ejection from a beading nozzle or other
dropletting process such that the duration of exposure of the
active principle to the higher temperature gelatin is limited so
reducing the degree of any heat-dependent degradation of the active
principle. This process may use any appropriate device such as, for
example, a homogenizer, e.g. a screw homogenizer, in conjunction
with an extrusion-type apparatus as described for example in WO
2008/132707 (Sigmoid Pharma) the entirety of which is incorporated
herein by reference.
[0307] Hydrophobic surfactant, if included, is added to the aqueous
phase conveniently at the same time the other components are added
e.g. polymer matrix material and plasticiser if included e.g. at
the beginning of the processing session. The physical form of the
surfactant at the point of introduction into the aqueous phase
during preparation may play a role in the ease of manufacture of
the composition according to the invention. As such, although
liquid surfactants can be employed, it is preferred to utilize a
surfactant which is in solid form (e.g. crystalline or powder) at
room temperature, particularly when the aqueous phase comprises
gelatin. Surfactant is added in the appropriate amount required to
achieve the proportion desired and as described above. In general
this leads to presence of surfactant in an amount between 0.8% and
1% (by weight) of the aqueous phase.
[0308] The dispersed phase material need not be heated unless it is
(semi-)solid at ambient temperature and any active principle and in
this case other dispersed phase components are usually added at
ambient temperature with stirring until clear. These other
components may include a volatile (or non-volatile) solvent in
addition to the solvent and/or surfactant if selected. The
appropriate amount of oil phase active principle (if any) is added
to achieve the target proportion. Stirring can continue for a few
minutes to a few hours, even overnight, depending on the active
principle (for example, an active may take several hours to be
fully dissolved). Where it is desired to include an oil e.g. a wax
oil which is not liquid or fully liquid at room temperature (e.g.
Solutol or Cremophor RH40) in the dispersed phase, slight warming
e.g. to 40-50.degree. C. is appropriate.
[0309] The colloid may be formed by addition of the dispersed phase
to the heated aqueous phase with stirring as described above. The
resultant colloid then has the composition of the solidified
minibeads described above but with water still present.
[0310] The colloid is then poured or introduced into a mould or
other vessel or poured onto sheets or between sheets or delivered
dropwise (or extruded) into another fluid such that the polymer
matrix-containing aqueous phase, on solidification, takes the form
of the mould, vessel, sheet or droplet/bead intended. It is
preferred to progress to mould-forming e.g. beading, without
delay.
[0311] Alternatively to moulding, specialised machinery can be
employed for example to create the hemispherical beads described
above (see section above entitled "Shape, Size and Geometry") in
which the invention takes the form of hemispherical beads. It is
possible to manufacture a single bead made from joining two such
hemispheres (i.e. a single bead having two distinct halves) by
using specialist apparatus in which two tubes through which two
different emulsions are flowing, normally of circular cross
section, are joined shortly before an extrusion point or nozzle
(which may be vibrating) into a single dual lumen tube with a flat
wall separating the two emulsion flows and which prevents the two
emulsions from coming into contact until the point of extrusion.
The cross-section of the joined dual-lumen tube up to the point of
extrusion therefore appears as two semicircles. In operation, the
two hemispherical emulsion flows combine to form a single,
substantially spherical, bead on extrusion such that normal
droplets are ejected/extruded for solidification.
[0312] Solidification can occur in a variety of ways depending on
the polymer of the matrix, for example by changing the temperature
around the mould, vessel, sheet, droplet/bead etc or by applying a
solidification fluid or hardening solution so that the moulded
shape is gelled or solidified. In certain embodiments both
temperature change and application of a solidifying fluid or
hardening solution are employed together or simultaneously.
[0313] In the preferred embodiment in which the composition of the
invention takes the form of minibeads, the minibeads may be formed
for example by dropping the liquid colloid dropwise into a fluid
which effects solidification. Where the viscosity of the colloid to
be beaded reaches a certain point, drop formation becomes more
difficult and specialised apparatus is then preferred.
[0314] In the case where solidification can be achieved by raising
or reducing temperature, the temperature of the solidification
fluid can be adapted to achieve solidification at the desired rate.
For example, when gelatin is used as the polymer matrix, the
solidification fluid is at a lower temperature than the temperature
of the emulsion thus causing solidification of the polymer matrix.
In this case, the solidification fluid is termed a cooling
fluid.
[0315] In the case where solidification can be achieved chemically,
e.g. by induction of cross-linking on exposure to a component of
the solidification fluid, the concentration of such component in
the solidification fluid and/or its temperature (or other
characteristic or content) can be adjusted to achieve the desired
rate and degree of solidification. For example, if alginate is
chosen as the polymer matrix, one component of the solidification
fluid may be a calcium-containing entity (such as, for example,
calcium chloride) able to induce cross-linking of the alginate and
consequent solidification. Alternatively, the same or similar
calcium-containing entity may be included (e.g. dispersed) in the
aqueous phase of the liquid colloid prior to beading and triggered
to induce cross-linking e.g. by applying a higher or lower pH to a
solidification fluid into which droplets of emulsion fall dropwise
or are introduced. Such electrostatic cross-linking can be varied
as to the resulting characteristics of the minibead by control of
calcium ion availability (concentration) and other physical
conditions (notably temperature). The solidification fluid may be a
gas (for example air) or a liquid or both. For example, when
gelatin is used as the polymer matrix, the solidification fluid can
be initially gaseous (e.g. droplets passing through cooling air)
and then subsequently liquid (e.g. droplets passing into a cooling
liquid). The reverse sequence may also be applied while gaseous or
liquid cooling fluids alone may also be used. Alternatively, the
fluid may be spray-cooled in which the colloid is sprayed into a
cooling gas to effect solidification.
[0316] In the case of gelatin or other water-soluble polymer
destined to form the immobilization matrix, it is preferred that
the solidification fluid be a non-aqueous liquid (such as, for
example, medium chain triglycerides, mineral oil or similar
preferably with low HLB to ensure minimal wetting) which can
conveniently be placed in a bath (cooling bath) to receive the
droplets of emulsion as they solidify to form beads. Use of a
non-aqueous liquid allows greater flexibility in choice of the
temperature at which cooling is conducted.
[0317] Where a liquid cooling bath is employed, it is generally
maintained at less than 20.degree. C., preferably maintained in the
range 5-15.degree. C., more preferably 8-12.degree. C. when
standard gelatin is used as the polymer matrix. If a triglyceride
is chosen as the cooling fluid in the cooling bath, a preferred
example is Miglyol 810 from Sasol.
[0318] If gelatin is selected as the polymer matrix, respect for
appropriate temperature ranges ensures solidification of the
gelatin at an appropriate rate to avoid destruction e.g. of
tertiary protein structure in the case where the active principle
is a protein.
[0319] If alginate is selected as the polymer matrix, a typical
method of making minibeads involves dropwise addition of a 3%
sodium alginate solution in which oil droplets are dispersed as
described above into a 4.degree. C. crosslinking bath containing
0.1 M calcium chloride to produce calcium alginate (this method can
be referred to as "diffusion setting" because the calcium is
believed to diffuse into the minibeads to effect cross-linking or
setting). Using a syringe pump, or Inotech machine, droplets can be
generated or extruded (e.g. at 5 mL/h if a pump is used) through a
sterile needle or other nozzle (described elsewhere herein) which
can be vibrating as discussed elsewhere herein. Airflow of between
15 and 20 L/min through 4.5 mm tubing can be applied downwards over
the needle to reduce droplet size if desired. Newly formed
minibeads can then be stirred in the calcium chloride bath for up
to an hour. If carrageenan is used as the polymer matrix both salt
and reduction in temperature e.g. by dropping into cooling oil may
be used to obtain solidification.
[0320] An alternative approach when using alginate is internal
gelation in which the calcium ions are dispersed in the aqueous
phase prior to their activation in order to cause gelation of
hydrocolloid particles. For example, this can be achieved by the
addition of an inactive form of the ion that will cause
crosslinking of the alginate, which is then activated by a change
in e.g. pH after sufficient dispersion of the ion is complete (see
Glicksman, 1983a; Hoefler, 2004 which are both incorporated herein
by reference). This approach is particularly useful where rapid
gelation is desired and/or where the diffusion approach may lead to
loss of API by diffusion thereof into the crosslinking bath.
[0321] Following shape-forming, moulding or beading, the resultant
shapes or forms may be washed then dried if appropriate. In the
case of minibeads solidified in a solidification fluid, an optional
final step in the method of production described above therefore
comprises removal of the solidified minibeads from the
solidification fluid. This may be achieved e.g. by collection in a
mesh basket through which the solidification fluid (e.g. MCT) is
drained and the beads retained and is preferably conducted without
delay e.g. as soon as the beads have formed or within 5, 10, 15,
20, 25 or 30 minutes of their formation. Excess solidification
fluid may then be removed using a centrifuge (or other apparatus or
machine adapted to remove excess fluid) followed by drying of the
beads to remove water or free water and/or removal of some or all
of any additional solvent e.g. ethanol or isopropyl alcohol used to
dissolve or facilitate dissolution of the active principle in
preceding steps optionally followed by washing (e.g. using ethyl
acetate) and a subsequent "drying" step to remove excess solvent
(e.g. ethyl acetate). Isopropyl alcohol is an example of a solvent
which is preferably removed later in processing to reduce residues
in the oil or aqueous phase. Drying can be achieved by any suitable
process known in the art such as use of a drum drier (e.g. Freund
Drum dryer which may be part of the Spherex equipment train if
used) with warm air at between 15.degree. C. and 25.degree. C.,
preferably around 20.degree. C. leading to evaporation or
entrainment of the water by the air. Use of gelatin as the polymer
matrix (e.g. as principal constituent of the aqueous immobilisation
phase) in most cases requires a drying step and for minibeads this
is preferably achieved by drying in air as above described. The
resultant composition (the composition of the invention) is
essentially dry as described in more detail above.
[0322] In terms of the way in which colloid droplets may be formed
in the first step of the beading process described above,
variations of the above described method are possible including
introducing droplets into a variety of solidification fluids.
[0323] In general, the minibeads may be generated by the
application of surface tension between the fluid colloid having an
aqueous continuous phase and an appropriate solidification fluid
such as, for example, gas or liquid in order to create the
spherical or substantially spherical shape of the ultimate
beads.
[0324] Alternatively, the minibeads may be produced through
ejection or extrusion of the liquid colloid through an orifice or
nozzle with a certain diameter and optionally subject to selected
vibrational frequencies and/or gravitational flow. Examples of
machines which may be used are the Freund Spherex, ITAS/Lambo,
Globex or Inotech processing equipment. Operation of the Spherex
machine manufactured by Freund as may be desired to manufacture
minibeads according to the present invention is described in U.S.
Pat. No. 5,882,680 (Freund), the entire contents of which are
incorporated herein by reference. It is preferred to select a
vibrational frequency in the region of 10-15 RPM although the
ultimate choice (and separately the amplitude of vibration
selected) depends on the viscosity of the colloid to be beaded. If
the polymer matrix is chosen to solidify at lower temperature, it
may be appropriate to maintain the lines to the orifice/nozzle at a
certain temperature to maintain the fluidity of the solution.
[0325] The Spherex machine (and others) may be adapted to make use
of a dual concentric lumen nozzle to ensure simultaneous extrusion
of two fluids, the fluid in the inner lumen forming a core and the
fluid of the outer lumen forming a capsule. The fluid forming the
capsule is solidified according to one of the methods described. It
may or may not be desirable for the fluid forming the core to be
susceptible of solidification to yield a particular embodiment of
the composition of the invention. The machinery adapted in this way
can be used to manufacture the composition of the invention in the
form of a capsule in which the core of the composition is filled
with a fluid (a gas or a liquid) as described in the section above
entitled "Shape, Size and Geometry" (noting that the core, like the
capsular material, may be a composition, albeit optionally a
distinct composition, according to the invention i.e. susceptible
of solidification according to one of the methods described above).
A three-lumen nozzle and appropriate tubing may be employed if it
is desired to include an intermediate internal layer e.g. internal
film layer of non-aqueous material on the inner face of the sphere
with the intermediate layer conveniently being solid at room
temperature. Thus, in terms of the softness/hardness of successive
layers, the composition may for example be described as solid:solid
in the case of two layers or solid:solid:solid in the case of 3
layers or liquid/semi-liquid:solid:solid in the case of 3
layers.
[0326] The preceding paragraphs describe the formation of uncoated
beads. It is a preferred embodiment of the present invention to
have coated beads which are described in more detail elsewhere
herein. Such coatings may be single or multiple and may be applied
in a number of ways (see separate section).
[0327] With regard to one of the methods described above (ejection
of colloid through an optionally vibrating nozzle) with two
concentric orifices (centre and outer), the outer fluid may form a
coat (outside the minibead) of e.g. polymeric material (polymeric
coating) which may contain an active principle or may impart
controlled release characteristics to the minibead and the inner
layer (core) may be a colloid as described herein. The Spherex
machine manufactured by Freund (see U.S. Pat. No. 5,882,680 to
Freund) is preferably used (the entire contents of this patent is
incorporated herein by reference).
[0328] Use of the Spherex machine achieves very high
monodispersity. For example, in a typical 100 g, batch 97 g of
minibeads were between 1.4 to 2 mm diameter or between 1 and 2 mm.
Desired size ranges can be achieved by methods known in the art for
rejecting/screening different sized particles. For example, it is
possible to reject/screen out the larger/smaller beads by passing a
batch first through e.g. a 2 mm mesh and subsequently through a 1.4
mm mesh.
[0329] The 1.4 to 2 mm diameter range is a good size if it is
desired to coat the minibeads (if smaller, the spray of the coating
machine may bypass the minibead; if too large hard, the beads may
be harder to fluidise which is necessary to achieve consistent
coating).
[0330] The minibeads are preferably internally (i.e.
cross-sectionally) homogeneous i.e. monolithic although processing
conditions may be varied for example by altering the temperature of
the liquid colloid, the solidification fluid and the concentration
of components in these fluids and the time allowed for certain
processing steps to occur including drying. Although not currently
preferred, such variations may be applied in the case of minibead
manufacture to achieve heterogeneity such as, for example, a harder
skin and softer core with less than complete immobilization of oil
droplets towards the core as opposed to the surface of the bead.
Larger (e.g. non-beaded) forms or shapes of the composition
according to the invention may particularly be engineered to embody
such heterogeneity. However, it is currently preferred to have
internally homogenous compositions and, within the minibead
embodiment, this can be favoured by conducting the
beading/dropletting using a homogeneous medium e.g. a well
dispersed colloid. Such homogeneity in the emulsion to be beaded
can help avoid the drying conditions affecting symmetry.
[0331] The oral composition may be used for a number of
applications as discussed elsewhere herein. The active principle(s)
may be released immediately (immediate release profile) or be
released after some delay and/or over an extended period (delayed
and/or extended release profile). For immediate release, the
minibeads or other formats may be uncoated or coated enterically to
protect against stomach acid for immediate release in the small
intestine.
[0332] Alternatively, if controlled release is desired (i.e.
delayed, extended or site-targeted release etc), or if
medium-independent release is desired, it is possible, according to
the invention to apply a coat to the minibeads or other formats.
Application of the appropriate coat may, for example if colonic
release is required, allow for say less than 10% of the active
principle to be dissolved (in dissolution medium) at 4 hours and
then a burst (sudden release) towards a maximum dissolution
(approaching 100%) in the subsequent 24 hours. Many alternative
target profiles are possible and this example is purely for
illustration.
[0333] Thus, the composition may be in the form of minibeads at
least some of which bear a coat (i.e. are coated) in order to
control release of active principle from the minibead. In one
embodiment, the coat is a film and in another embodiment, it is a
membrane. The coat, film or membrane comprises one or more
substances preferably of a polymeric nature (e.g. methacrylates
etc; polysaccharides etc as described in more detail below) or
combination of more than one such substance, optionally including
other excipients or active principles, such as, for example,
plasticizers, described e.g. in the sections above on active
principles. Preferred plasticizers, if they are used, include
hydrophilic plasticizers for example triethyl citrate (TEC) which
is particularly preferred when using the Eudragit family of
polymers as coatings as described below. Another preferred
plasticiser, described in more detail below in relation to coating
with ethyl cellulose, is DBS. Alternative or additional optionally
included excipients are glidants. A glidant is a substance that is
added to a powder or other medium to improve its flowability. A
typical glidant is talc which is preferred when using the Eudragit
family of polymers as coatings.
Non-Dried Colloid Formulations
[0334] The invention does not require that the steroid be
administered as a dried colloidal formulation. The steroid could be
incorporated into a minibead comprising a water soluble polymer
matrix and not containing a dispersed phase. The steroid may
therefore be water soluble and be dissolved and/or dispersed in the
water soluble polymer matrix. Alternatively the steroid may be
water-insoluble and be dispersed in the water soluble polymer
matrix. Such a minibead may be prepared by a method as disclosed
herein where the dispersed phase is not added to the mix that forms
the minibead.
[0335] The steroid may be administered as any suitable formulation
which releases the steroid in the desired region(s) of the GIT. For
example, the steroid may be budesonide administered as a
multi-matrix formulation budesonide MMX.RTM.. See WO0076478 for
more information as to such multi-matrix formulations; WO0076478 is
incorporated herein in its entirety.
[0336] The steroid may be budesonide administered as Entocort.RTM.
EC.
[0337] The formulation may comprise the steroid in solution in a
liquid, semi-solid or solid, for example in an oily or waxy medium,
or in the hydrophobic part of a self-assembly structure.
[0338] The steroid may be administered as a multiple mini-unit
formulation, comprising a multiplicity of mini-tablets,
minicapsules and or pellets etc. The mini-units may comprise the
steroid in solid solution, semi-solid solution or liquid solution.
The mini-units may be minibeads. The mini-beads may comprise the
steroid in liquid solution.
[0339] The steroid may be administered as a two layer minibead.
Such a minibeads may be made using an aqueous phase comprising a
water soluble polymer and a hydrophobic or water-immiscible phase
respectively through the outer and inner orifices of a nozzle
having a central inner orifice and, arranged concentrically
therearound, an outer orifice. The aqueous phase and the
hydrophobic or water-immiscible phase may be as described herein in
relation to dried emulsion minibeads. Such two layer minibeads and
their manufacture are described, for example, in WO 2008/122967 of
Sigmoid Pharma Limited, which is included herein by reference.
[0340] Active agents which are more readily water-soluble, e.g. the
hydroxylase inhibitor hydralazine, may be incorporated in a
hydrophilic phase (e.g. a water-soluble polymer) in dissolved or
particulate form.
[0341] Solid dosage forms for oral administration include capsules,
minicapsules, beads, powders and granules. In such solid dosage
forms, the active compound is typically mixed with at least one
inert, pharmaceutically acceptable excipient or carrier such as
sodium citrate or dicalcium phosphate and/or one or more: a)
fillers or extenders such as starches, lactose, sucrose, glucose,
mannitol and silicic acid; b) binders such as
carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone,
sucrose and acacia; c) humectants such as glycerol; d)
disintegrating agents such as agar-agar, calcium carbonate, potato
or tapioca starch, alginic acid, certain silicates and sodium
carbonate; e) solution retarding agents such as paraffin; f)
absorption accelerators such as quaternary ammonium compounds; g)
wetting agents such as cetyl alcohol and glycerol monostearate; h)
absorbents such as kaolin and bentonite clay and i) lubricants such
as talc, calcium stearate, magnesium stearate, solid polyethylene
glycols, sodium lauryl sulfate and mixtures thereof. In the case of
capsules, tablets and pills, the dosage form may also comprise
buffering agents. Solid compositions of a similar type may also be
employed as fillers in soft and hard-filled gelatin capsules using
such excipients as lactose or milk sugar as well as high molecular
weight polyethylene glycol, for example.
[0342] Liquid dosage forms for oral administration include
pharmaceutically acceptable emulsions, solutions, suspensions,
syrups and elixirs. In addition to the steroid, the liquid dosage
forms may contain inert diluents commonly used in the art such as
water or other solvents, solubilizing agents and emulsifiers such
as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl
acetate, benzyl alcohol, benzyl benzoate, propylene glycol,
1,3-butylene glycol, dimethyl formamide, oils (in particular,
cottonseed, groundnut, corn, germ, olive, castor, and sesame oils),
glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and
fatty acid esters of sorbitan and mixtures thereof. Besides inert
diluents, the oral compositions may also include excipients such as
wetting agents, emulsifying and suspending agents, sweetening,
flavoring and perfuming agents. Suspensions, in addition to the
steroid, may contain suspending agents such as ethoxylated
isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters,
microcrystalline cellulose, aluminum metahydroxide, bentonite,
agar-agar, and tragacanth and mixtures thereof.
[0343] Compositions for rectal or vaginal administration are
preferably suppositories which can be prepared by mixing the
steroid with suitable non-irritating excipients or carriers such as
cocoa butter, polyethylene glycol or a suppository wax which are
solid at room temperature but liquid at body temperature and
therefore melt in the rectum or vaginal cavity and release the
steroid.
[0344] Suitably, the formulations contain a dissolution aid. The
dissolution aid is not limited as to its identity so long as it is
pharmaceutically acceptable. Examples include non-ionic
surfactants; ionic surfactants; and amphoteric surfactants.
[0345] The solid dosage forms can be prepared with coatings and
shells as well known in the pharmaceutical formulating art and
described elsewhere herein. They may optionally contain opacifying
agents and may also be of a composition such that they release the
active ingredient(s) only, or preferentially, in a certain part of
the intestinal tract, and/or in delayed fashion.
[0346] A solid dosage form may comprise a waxy phase in which one
or more active agents are dissolved. Suitable waxy materials are
described elsewhere herein.
Coating
[0347] The formulations described herein are typically provided
with a controlled release coating. Such a controlled release
coating may comprise a polymer or a combination of polymers, as is
well known.
[0348] In the case of combinations of polymers, combinations may be
selected in order to achieve the desired delay (or other change) in
the release of the drug and/or poration of the coating and/or
exposure of the minibead or other format within the coating to
allow egress of drug and/or dissolution of the immobilization
matrix. In one embodiment, two types of polymers are combined into
the same polymeric material, or provided as separate coats that are
applied to the minibeads.
[0349] It has previously been stated that the formulations may
comprise more than one population of minibeads. Within the coating
embodiment, the differences between populations may lie in the coat
i.e. two (or more) populations of minibeads may differ in a number
of respects one of which is the coating.
[0350] The coat may be applied as described below and may vary as
to thickness and density. The amount of coat is defined by the
additional weight added to (gained by) the dried composition (e.g.
minibead) of the invention. Weight gain is preferably in the range
0.1% to 50%, preferably from 1% to 15% of the dry weight of the
bead, more preferably in the range 3% to 10%, or in the range
3%-7%, or in the range 5-12%, or in the range 8-12%.
[0351] The polymeric coating material may comprise methacrylic acid
co-polymers, ammonio methacrylate co-polymers, or mixtures thereof.
Methacrylic acid co-polymers such as, for example, EUDRAGIT.TM. S
and EUDRAGIT.TM. L (Evonik) are particularly suitable. These
polymers are gastroresistant and enterosoluble polymers. Their
polymer films are insoluble in pure water and diluted acids. They
may dissolve at higher pHs, depending on their content of
carboxylic acid. EUDRAGIT.TM. S and EUDRAGIT.TM. L can be used as
single components in the polymer coating or in combination in any
ratio. By using a combination of the polymers, the polymeric
material can exhibit solubility at a variety of pH levels, e.g.
between the pHs at which EUDRAGIT.TM. L and EUDRAGIT.TM. S are
separately soluble.
[0352] The trademark "EUDRAGIT" is used hereinafter to refer to
methacrylic acid copolymers, in particular those sold under the
EUDRAGIT.TM. by Evonik.
[0353] The coating can comprise a polymeric material comprising a
major proportion (e.g., greater than 50% of the total polymeric
coating content) of at least one pharmaceutically acceptable
water-soluble polymer, and optionally a minor proportion (e.g.,
less than 50% of the total polymeric content) of at least one
pharmaceutically acceptable water insoluble polymer. Alternatively,
the membrane coating can comprise a polymeric material comprising a
major proportion (e.g., greater than 50% of the total polymeric
content) of at least one pharmaceutically acceptable water
insoluble polymer, and optionally a minor proportion (e.g., less
than 50% of the total polymeric content) of at least one
pharmaceutically acceptable water-soluble polymer.
[0354] Ammonio methacrylate co-polymers such as, for example,
EUDRAGIT.TM. RS and EUDRAGIT.TM. RL (Evonik) are suitable for use
in the present invention. These polymers are insoluble in pure
water, dilute acids, buffer solutions, and/or digestive fluids over
the entire physiological pH range. The polymers swell in water and
digestive fluids independently of pH. In the swollen state, they
are then permeable to water and dissolved active agents. The
permeability of the polymers depends on the ratio of ethylacrylate
(EA), methyl methacrylate (MMA), and trimethylammonioethyl
methacrylate chloride (TAMCl) groups in the polymer. For example,
those polymers having EA:MMA:TAMCl ratios of 1:2:0.2 (EUDRAGIT.TM.
RL) are more permeable than those with ratios of 1:2:0.1
(EUDRAGIT.TM. RS). Polymers of EUDRAGIT.TM. RL are insoluble
polymers of high permeability. Polymers of EUDRAGIT.TM. RS are
insoluble films of low permeability. A particularly preferred
diffusion-controlled pH-independent polymer in this family is RS 30
D which is a copolymer of ethyl acrylate, methyl methacrylate and a
low content of methacrylic acid ester with quaternary ammonium
groups present as salts to make the polymer permeable. RS 30 D is
available as an aqueous dispersion.
[0355] The amino methacrylate co-polymers can be combined in any
desired ratio, and the ratio can be modified to modify the rate of
drug release. For example, a ratio of EUDRAGIT.TM. RS:EUDRAGIT.TM.
RL of 90:10 can be used. Alternatively, the ratio of EUDRAGIT.TM.
RS:EUDRAGIT.TM. RL can be about 100:0 to about 80:20, or about
100:0 to about 90:10, or any ratio in between. In such
formulations, the less permeable polymer EUDRAGIT.TM. RS generally
comprises the majority of the polymeric material with the more
soluble RL, when it dissolves, permitting gaps to be formed through
which solutes can come into contact with the minibead allowing
pre-dissolved pharmaceutical actives to escape in a controlled
manner.
[0356] The amino methacrylate co-polymers can be combined with the
methacrylic acid co-polymers within the polymeric material in order
to achieve the desired delay in the release of the drug and/or
poration of the coating and/or exposure of the minibead within the
coating to allow egress of drug and/or dissolution of the
immobilization or water-soluble polymer matrix. Ratios of ammonio
methacrylate co-polymer (e.g., EUDRAGIT.TM. RS) to methacrylic acid
co-polymer in the range of about 99:1 to about 20:80 can be used.
The two types of polymers can also be combined into the same
polymeric material, or provided as separate coats that are applied
to the minibeads.
[0357] Eudragit.TM. FS 30 D is an anionic aqueous-based acrylic
polymeric dispersion consisting of methacrylic acid, methyl
acrylate, and methyl methacrylate and is pH sensitive. This polymer
contains fewer carboxyl groups and thus dissolves at a higher pH
(>6.5). The advantage of such a system is that it can be easily
manufactured on a large scale in a reasonable processing time using
conventional powder layering and fluidized bed coating techniques.
A further example is EUDRAGIT.RTM. L 30D-55 which is an aqueous
dispersion of anionic polymers with methacrylic acid as a
functional group. It is available as a 30% aqueous dispersion.
[0358] In addition to the EUDRAGIT.TM. polymers described above, a
number of other such copolymers can be used to control drug
release. These include methacrylate ester co-polymers such as, for
example, the EUDRAGIT.TM. NE and EUDRAGIT.TM. NM ranges. Further
information on the EUDRAGIT.TM. polymers can be found in "Chemistry
and Application Properties of Polymethacrylate Coating Systems," in
Aqueous Polymeric Coatings for Pharmaceutical Dosage Forms, ed.
James McGinity, Marcel Dekker Inc., New York, pg. 109-114, the
entirety of which is incorporated herein by reference.
[0359] Several derivatives of hydroxypropyl methylcellulose (HPMC)
also exhibit pH dependent solubility and may be used in the
invention for coating. These include hydroxypropyl methylcellulose
phthalate (HPMCP), which rapidly dissolves in the upper intestinal
tract and hydroxypropyl methylcellulose acetate succinate (HPMCAS)
in which the presence of ionizable carboxyl groups causes the
polymer to solubilize at high pH (>5.5 for the LF grade and
>6.8 for the HF grade). These polymers are commercially
available from Shin-Etsu Chemical Co. Ltd. As with other polymers
described herein as useful for coatings, HPMC and derivatives may
be combined with other polymers e.g. EUDRAGIT RL-30 D.
[0360] It is particularly preferred according to the invention to
use a polymeric coating substance which is pH-independent in its
dissolution profile and/or in its ability to release active
principles incorporated in the minibeads of the invention. Examples
have already been given (e.g., Eudragit RS and RL). Another example
of a pH-independent polymeric coating substance is ethylcellulose.
It will be understood that an ethylcellulose composition for use in
coating a dosage form for may comprise in addition to
ethylcellulose and, in the case of a liquid composition, a liquid
vehicle, one or more other components. The other components may
serve to modulate the properties of the composition, e.g.
stability. The ethylcellulose may be the sole controlled release
polymer in such a composition. The ethylcellulose may be in an
amount of at least 50%, at least 60%, at least 70%, at least 80%,
at least 90% or at least 95% by weight of the dry weight of
composition for use in coating a dosage form. Accordingly, an
ethylcellulose coating may include other components in addition to
the ethycellulose. The ethylcellulose may be in an amount of at
least 50%, at least 60%, at least 70%, at least 80%, at least 90%
or at least 95% by weight of the ethylcellulose coating.
[0361] A particular ethylcellulose coating composition which may be
applied to the compositions of the invention is a dispersion of
ethylcellulose in a sub-micron to micron particle size range, e.g.
from about 0.1 to 10 microns in size, homogeneously suspended in
water with the aid of an emulsification agent, e.g. ammonium
oleate. The ethylcellulose dispersion may optionally and preferably
contain a plasticizer, for example dibutyl sebacate (DBS) or medium
chain triglycerides. Such ethylcellulose dispersions may, for
example, be manufactured according to U.S. Pat. No. 4,502,888,
which is incorporated herein by reference. One such ethylcellulose
dispersion suitable for use in the present invention and available
commercially is marketed under the trademark Surelease.RTM., by
Colorcon of West Point, Pa. USA. In this marketed product, the
ethylcellulose particles are, e.g., blended with oleic acid and a
plasticizer, then optionally extruded and melted. The molten
plasticized ethylcellulose is then directly emulsified, for example
in ammoniated water optionally in a high shear mixing device, e.g.
under pressure. Ammonium oleate can be formed in situ, for instance
to stabilize and form the dispersion of plasticized ethylcellulose
particles. Additional purified water can then be added to achieve
the final solids content. See also U.S. Pat. No. 4,123,403, which
is incorporated herein by reference.
[0362] The trademark "Surelease.RTM." is used hereinafter to refer
to ethylcellulose coating materials, for example a dispersion of
ethylcellulose in a sub-micron to micron particle size range, e.g.
from about 0.1 to 10 microns in size, homogeneously suspended in
water with the aid of an emulsification agent, e.g. ammonium
oleate. In particular, the trademark "Surelease.RTM." is used
herein to refer to the product marketed by Colorcon under the
Surelease.RTM. trademark.
[0363] Surelease.RTM. dispersion is an example of a combination of
film-forming polymer, plasticizer and stabilizers which may be used
as a coating to adjust rates of active principle release with
reproducible profiles that are relatively insensitive to pH. The
principal means of drug release is by diffusion through the
Surelease.RTM. dispersion membrane and is directly controlled by
film thickness. Use of Surelease.RTM. is particularly preferred and
it is possible to increase or decrease the quantity of
Surelease.RTM. applied as coating in order to modify the
dissolution of the coated minibead. Unless otherwise stipulated,
use of the term "Surelease" may apply to Surelease E-7-19020,
E-7-19030, E-7-19040 or E-7-19050. E-7-19020 comprises
ethylcellulose blended with oleic acid and dibutyl sebacate, then
extruded and melted. The molten plasticized ethylcellulose is then
directly emulsified in ammoniated water in a high shear mixing
device under pressure. Ammonium oleate is formed in situ to
stabilize and form the dispersion of plasticized ethylcellulose
particles. Additional purified water is then added to achieve the
final solids content. E-7-19030 additionally comprises colloidal
anhydrous silica dispersed into the material. E-7-19040 is like
E-7-19020 except that it comprises medium chain triglycerides
instead of dibutyl sebacate. E-7-19050 derives from blending
ethylcellulose with oleic acid before melting and extrusion. The
molten plasticized ethylcellulose is then directly emulsified in
ammoniated water in a high shear mixing device under pressure.
Ammonium oleate is formed in situ to stabilize and form the
dispersion of plasticized ethylcellulose particles. However,
E-7-19040 is preferred.
[0364] The invention also contemplates using combinations of
Surelease with other coating components, for example sodium
alginate, e.g. sodium alginate available under the trade name
Nutrateric.TM..
[0365] In addition to the EUDRAGIT.TM. and Surelease.RTM. polymers
discussed above, other enteric, or pH-dependent, polymers can be
used. Such polymers can include phthalate, butyrate, succinate,
and/or mellitate groups. Such polymers include, but are not limited
to, cellulose acetate phthalate, cellulose acetate succinate,
cellulose hydrogen phthalate, cellulose acetate trimellitate,
hydroxypropyl-methylcellulose phthalate,
hydroxypropylmethylcellulose acetate succinate, starch acetate
phthalate, amylose acetate phthalate, polyvinyl acetate phthalate,
and polyvinyl butyrate phthalate. Additionally, where compatible,
any combination of polymer may be blended to provide additional
controlled- or targeted-release profiles.
[0366] The coating can further comprise at least one soluble
excipient to increase the permeability of the polymeric material.
Suitably, the at least one soluble excipient is selected from among
a soluble polymer, a surfactant, an alkali metal salt, an organic
acid, a sugar, and a sugar alcohol. Such soluble excipients
include, but are not limited to, polyvinyl pyrrolidone,
polyethylene glycol, sodium chloride, surfactants such as, for
example, sodium lauryl sulfate and polysorbates, organic acids such
as, for example, acetic acid, adipic acid, citric acid, fumaric
acid, glutaric acid, malic acid, succinic acid, and tartaric acid,
sugars such as, for example, dextrose, fructose, glucose, lactose,
and sucrose, sugar alcohols such as, for example, lactitol,
maltitol, mannitol, sorbitol, and xylitol, xanthan gum, dextrins,
and maltodextrins. In some embodiments, polyvinyl pyrrolidone,
mannitol, and/or polyethylene glycol can be used as soluble
excipients. The at least one soluble excipient can be used in an
amount ranging from about 1% to about 10% by weight, based on the
total dry weight of the polymer.
[0367] The modifications in the rates of release, such as to create
a delay or extension in release, can be achieved in any number of
ways. Mechanisms can be dependent or independent of local pH in the
intestine, and can also rely on local enzymatic activity to achieve
the desired effect. Examples of modified-release formulations are
known in the art and are described, for example, in U.S. Pat. Nos.
3,845,770; 3,916,899; 3,536,809; 3,598,123; 4,008,719; 5,674,533;
5,059,595; 5,591,767; 5,120,548; 5,073,543; 5,639,476; 5,354,556;
and 5,733,566 all of which are incorporated herein by reference in
their entirety.
[0368] As noted above, pH-independent coating polymers may be used,
for example ethylcellulose, as previously discussed. In the case of
a dosage form targeting the steroid and any other actives to the
ileum and/or colon, the addition to an ethylcellulose (e.g.
Surelease.TM.) or other pH-independent coating of a second polymer
(e.g. a polysaccharide, especially a heteropolysaccharide) which is
susceptible to degradation by bacterial enzymes but not by
digestive enzymes, e.g. human digestive enzymes, helps ensure that
the barrier function of the coating is destroyed by the action of
such enzymes in the terminal ileum and/or colon, thereby ensuring
release of the actives in the ileum and/or colon. The inclusion of
such a bacterial enzyme-degradable polymer in a pH-independent
coating, e.g. ethylcellulose, provides flexibility in modulating
the amount of polymer added to the minibeads of the invention in
order to achieve optimal dissolution profiles. In general terms,
therefore, the disclosure includes formulations as described herein
which comprise a coating comprising a combination of a delayed
release material, for example an erodible polymer e.g.
ethylcellulose, and a polymer susceptible of degradation by
bacterial enzymes in the colon, e.g. a polysaccharide and
particularly a water-soluble polysaccharide, particularly a
pectin.
[0369] The disclosure therefore includes a coating for compositions
intended to release their active payload in the colon which is a
combination of ethylcellulose (preferably formulated with an
emulsification agent such as, for example, ammonium oleate and/or a
plasticizer such as, for example, dibutyl sebacate or medium chain
triglycerides) and a polysaccharide susceptible of degradation by a
bacterial enzyme normally found in the colon. Such polysaccharides
include chondroitin sulphate, pectin, dextran, guar gum and
amylase, chitosan etc and derivatives of any of the foregoing.
Chitosan is particularly preferred in connection with obtaining a
colon-specific release profile. The disclosure also includes a
composition comprising a combination of ethylcellulose (preferably
formulated with an emulsification agent such as, for example,
ammonium oleate and/or a plasticizer such as, for example, dibutyl
sebacate or medium chain triglycerides) and a polysaccharide
susceptible of degradation by a bacterial enzyme normally found in
the colon; the composition may include a liquid vehicle, e.g.
water.
[0370] The use of polysaccharides by themselves for coating
purposes has been tried with limited success. Most of the
non-starch polysaccharides suffer from the drawback of lacking good
film forming properties. Also, they tend to swell in the GI tract
and become porous, resulting in the early release of the drug. Even
amorphous amylose, which is resistant to degradation by pancreatic
alpha amylase but capable of degradation by colonic bacterial
enzymes has the disadvantage of swelling in aqueous media although
this can be controlled by incorporating insoluble polymers like,
ethyl cellulose and acrylates into the amylose film. Amylose
however is not water-soluble and although water-soluble
polysaccharides are not excluded, the present inventors have found
that use of a water-soluble polysaccharide (WSP) susceptible of
bacterial enzymic degradation brings particularly advantageous
results when used as a coating in accordance with this embodiment
of the present invention. A particularly preferred polysaccharide
in this embodiment of the present invention is pectin. Various
kinds of pectin may be used including pectin of different grades
available i.e. with differing degrees of methylation (DM), i.e.
percentage of carbonyl groups esterified with methanol, for example
pectins with a DM of more than 50%, known as High Methoxy (HM)
Pectins or Low Methoxy (LM) pectins, or a pectin combination
comprising an HM pectin and an LM pectin. It is also possible in
this embodiment to use pectins having various degrees of
acetylation (DAc). Taken together, the DM and DAc or the degree of
substitution is known as Degree of Esterification (DE). Pectins of
various DE's may be used according to the invention. As an
alternative to pectin, sodium alginate may be used as a
polysaccharide according to an embodiment of the invention.
However, other embodiments may conveniently include amylose and/or
starch which contains amylose. Various grades of starch, containing
different percentages of amylose may be used including for example
Hylon V (National Starch Food Innovation) which has an amylose
percentage of 56% or Hylon VII which has an amylose percentage of
70%. The remaining percentage is amylopectin. The polysaccharides
pectin, amylose and sodium alginate are particularly preferred for
achieving colon delivery i.e. for compositions intended to release
active principles in the colon.
[0371] It has been found that pectin can act as a former of pores
in the coating otherwise provided by ethylcellulose (preferably
Surelease). By "pores" is not meant shaft-like holes from the
surface to the core of the minibead, rather areas of weakness or
absence of coating occurring stochastically on and within the
coating of the invention.
[0372] Pore formers have been described before in connection with
Surelease (see e.g. US 2005/0220878) but in relation to
"gastro-insoluble" substances such as, for example, alginate.
[0373] Where the water-soluble polysaccharide (WSP) is pectin, the
proportion of ethylcellulose or Surelease.TM. to pectin is ideally
in the range 90:10 to 99:1, preferably, 95:5 to 99:1, more
preferably 98:2 to 99:1.
[0374] In this particularly preferred combination (ethylcellulose
or Surelease.TM.+WSP e.g. pectin) the weight gain and ratio between
ethylcellulose or Surelease.TM. and WSP can be varied to refine the
behaviour of the coating and the composition of the invention when
it bears such a coat. Thus to the inventors/applicant's surprise,
the advantages of this preferred combination of coating polymers
were further pronounced by selecting a weight gain in the range 0
to 30% (preferably 5 to 10%) and a weight ratio of ethylcellulose
or Surelease to pectin in the range 95:5 to 99.5:0.5 preferably
97:3 to 99:1 inclusive. Particularly favoured weight gains using
ethylcellulose or Surelease are those in the range 5-12% or in the
range 8-12%.
[0375] Although the focus above has been on extending and/or
sustaining release of active principles from minibeads or other
formats, also contemplated are uncoated or simple enteric coated
minibeads or other formats providing early, small intestinal API
release with sufficient enteric coating merely to protect the
minibeads from dissolution in the stomach.
[0376] It is preferred to dry the minibeads before they are coated
with a suitable polymeric coat (as described in more detail
above/below). It is also preferred, in certain embodiments to apply
a first coat before applying a second. In general the first coat
and the second coat may be of the same or different materials and
be chosen from any of the classes of coating material described
herein. In specific embodiments, the first coat optionally protects
the core (bead) from interaction with the second coat and/or
prevents leaching of bead contents into the second coat. For
example, the first coat may comprise or be hypromellose, e.g. it
may be made with a mixture of hypromellose, titanium dioxide and
polyethylene glycol; the first coat may comprise at least 50 wt %
hypromellose and optionally at least 75 wt % hypromellose, e.g. at
least 80 wt % or at least 85 wt % or 90 wt % hypromellose. The
coating material used to form the first coat may therefore comprise
a dry weight percentage of hypromellose mentioned in the preceding
sentence. The second (outer) coat may be an enteric coating as
described above or comprise a mixture of polymers including a
polymer degradable by bacterial or other enzymes, for example be
made of the Surelease-pectin mixture described above. If it is
desired for the first coat to use a mixture of 5 hypromellose,
titanium dioxide and polyethylene glycol, commercial products
corresponding to such mixtures are available including Opadry
White, a product commercialised by Colorcon. More generally,
various products commercialised under the trade name Opadry and
Opadry II. Further nonlimiting examples include Opadry YS-1-7706-G
white, Opadry Yellow 03B92357, Opadry Blue 03B90842). These
compositions are available as dry film coating compositions that
can be diluted in water shortly before use. Opadry and Opadry II
formulations comprise a cellulosic film forming polymer (e.g., HPMC
and/or HPC), and may contain polydextrose, maltodextrin, a
plasticizer (e.g., triacetin, polyethylene glycol), polysorbate 80,
a colorant (e.g., titanium dioxide, one or more dyes or lakes),
and/or other suitable film-forming polymers (e.g.,
acrylate-methacrylate copolymers). Suitable OPADRY or OPADRY II
formulations may comprise a plasticizer and one or more of
maltodextrin, and polydextrose (including but not limited to a)
triacetin and polydextrose or maltodextrin or lactose, or b)
polyethylene glycol and polydextrose or maltodextrin). Particularly
preferred commercial products are Opadry White (HPMC/HPC-based) and
Opadry II White (PVA/PEG-based). Alternative (non-Opadry) products
for initial protective coats include polyvinyl alcohol-polyethylene
glycol graft copolymers such as is available commercially under the
name Kollicoat IR and methyl methacrylate ammonium-based copolymers
such as are available commercially under the name Eudragit E.
Another preferred example is low molecular weight HPMC. The
optional inner coat is applied in the same manner as is the outer
(or sole) coat (or coating layer).
[0377] The coating process can be carried out by any suitable means
such as, for example, by use of a coating machine which applies a
solution of a polymer coat (as described above in particular) to
the minibeads. Polymers for coating are either provided by the
manufacturer in ready-made solutions for direct use or can be made
up before use following manufacturers' instructions.
[0378] Appropriate coating machines are known to persons skilled in
the art and include, for example, a perforated pan or fluidized-bed
system for example the GLATT, Vector (e.g. CF 360 EX), ACCELACOTA,
Diosna, O'Hara and/or HICOATER processing equipment. To be
mentioned is the MFL/01 Fluid Bed Coater (Freund) used in the
"Bottom Spray" configuration.
[0379] Typical coating conditions are as follows:
TABLE-US-00003 Process Parameter Values Fluidising airflow (m3/h)
20-60 (preferably 30-60) Inlet air temperature (.degree. C.) 20-65
Exhaust air temperature (.degree. C.) 38-42 Product temperature
(.degree. C.) 38-42 Atomizing air pressure (bar) Up to 1.4 e.g.
0.8-1.2 Spray rate (g/min) 2-10 and 3-25 RPM
[0380] Whether as part of the polymeric coat or independently
thereof, the minibeads of the disclosure may be coated with
additional drug layers using methods conventional in the art of
pharmaceutical science (such as for example using coating machines
as just described) to produce a composition having one or more
layer(s), each layer containing one or more active pharmaceutical
or other ingredient/excipient as described elsewhere herein. Drug
layering means the deposition of at least one or successive layers
of drug entities from solution, suspension or dry powder on nuclei
e.g. minibeads as described herein. Drug layering includes
solution/suspension layering, powder layering and powder drug
layering. In solution/suspension layering, drug particles are
dissolved or suspended in a binding liquid. In powder layering,
complete dissolution does not occur, due to low liquid saturation,
irrespective of the solubility of the active agent in the binding
liquid. In powder drug layering, a binder solution is first sprayed
onto previously prepared inert seeds e.g. minibeads as described
herein, followed by the addition of powder. Conventional pan
coaters may be used as described above for polymer coating although
modified forms of pan coaters are preferred including fluidised-bed
and centrifugal rotary granulators. Examples of suitable
granulators include the Rotor granulator. (Glatt), the
Rotor-processor (Aeromatic), the Spir-a-Flow (Freund) and the
CF-granulator (Freund). In applying a drug layer, the drug to be
layered onto the minibead may optionally first be admixed with
appropriate excipients such as, for example, binders as described
elsewhere herein. A particularly preferred binder in this context
is polyvinyl pyrrolidone (also spelt polyvinylpyrrolidone and also
known as PVP or povidone). PVPs of various K-values may be used.
The K-value of PVP is a function of its average molecular weight,
the degree of polymerization, and the intrinsic viscosity. It is
particularly preferred to use PVP K-32. Up to 5% of the dry weight
of the composition of the invention in this embodiment may be made
up of such binders. Approximately 1% or less is preferred. Other
suitable binders which may be used in drug-layering include
gelatin, carboxymethyl cellulose, hydroxypropyl methylcellulose and
hydrolysed starches e.g. maltodextrins. Compositions embodying drug
layering may also optionally be coated with a polymer coating, or
include a polymer layer, to control release as described more
generally above including the option to include the same or a
different active principle in this polymer coat.
[0381] The layered bead or minibead may have a plurality of layers,
e.g. 2, 3, 4 or 5 layers, comprising an active principle, wherein
the active principle of each layer is selected independently from
the active principle of each other layer. In one embodiment, each
layer comprises the same active principle as each other layer; in
another embodiment, no two layers comprise the same active
principle. The term "active principle" in this paragraph embraces
both a single active entity and a combination of active entities.
The layered bead or minibead may comprise one or more polymer
layers, to control release as described more generally above. Such
a polymer layer may contain an active principle and therefore
constitute a drug layer as well as a release control layer.
Alternatively, a polymer layer may be free of active principle. A
polymer layer, whether or not it contains an active principle, may
be located between the core and a drug layer outside the polymer
layer, or between two drug layers, or may form an outer layer.
[0382] The polymer layer may be located between the core and the
active principle layer. The polymer layer may be located externally
of the active principle layer. The layered bead or minibead may
comprise a plurality of active principle layers and, additionally
or alternatively, it may comprise a plurality of polymer layers. In
some embodiments, there is at least one active principle layer
which comprises a release-controlling polymer. In some embodiments,
the outermost layer comprises a release-controlling polymer, which
may contain an active principle or, in another implementation, be
free of active principle.
[0383] The optionally coated minibeads may be formulated directly
following their manufacture in the ways described above. In an
alternative embodiment, it may be desired to impart different
properties to the minibeads and/or to a final solid dosage product.
One way of achieving this according to the invention is through
granulation e.g. to improve the flow of powder mixtures of
minibeads with other components as e.g. described above in relation
to binders. Granules of intact or broken minibeads may be obtained
by adding liquids (e.g. binder or solvent solutions) and effecting
a granulating step as described in the prior art. Larger quantities
of granulating liquid produce a narrower particle size range and
coarser and harder granules, i.e. the proportion of fine granulate
particles decreases. The optimal quantity of liquid needed to get a
given particle size may be chosen in order to minimise
batch-to-batch variations. According to this embodiment, wet
granulation is used to improve flow, compressibility,
bio-availability, homogeneity, electrostatic properties, and
stability of the composition of the invention presented as a solid
dosage form. The particle size of the granulate is determined by
the quantity and feeding rate of granulating liquid. Wet
granulation may be used to improve flow, compressibility,
bio-availability, and homogeneity of low dose blends, electrostatic
properties of powders, and stability of dosage forms. A wet
granulation process according to this embodiment may employ low or
high shear mixing devices in which a low viscosity liquid
(preferably water) is added to a powder blend containing binder
previously dry mixed with the rest of the formulation including
minibeads. Alternative granulation approaches which may be utilized
include high-shear, extrusion and conventional wet granulation.
[0384] The invention contemplates a treatment that attains one or
more of the following objectives as compared to those now
available: (i) greater efficacy; (ii) fewer side effects; (iii)
reduced systemic drug levels; (iv) reduced cost; (v) improved
manufacturing method, (vi) an alternative treatment or
prophylactic.
[0385] The invention further includes the subject matter of the
following clauses:
1. A steroid for use in enteral administration and for use in
treating intestinal fibrosis. 2. A steroid for use of clause 1 for
use in oral administration. 3. A steroid for use of clause 1 or
clause 2 which is selected from aclometasone, aclometasone
dipropionate, aldosterone, amcinonide, beclomethasone,
beclomethasone dipropionate, betamethasone, betamethasone
dipropionate, betamethasone sodium phosphate, betamethasone
valerate, budesonide, clobetasone, clobetasone butyrate, clobetasol
propionate, cloprednol, cortisone, cortisone acetate, cortivazol,
deoxycortone, desonide, desoximetasone, dexamethasone,
dexamethasone sodium phosphate, dexamethasone isonicotinate,
difluorocortolone, fluclorolone, flumethasone, flunisolide,
fluocinolone, fluocinolone acetonide, fluocinonide, fluocortin
butyl, fluorocortisone, fluorocortolone, fluocortolone caproate,
fluocortolone pivalate, fluorometholone, fluprednidene,
fluprednidene acetate, flurandrenolone, fluticasone, fluticasone
propionate, halcinonide, hydrocortisone, hydrocortisone acetate,
hydrocortisone butyrate, hydrocortisone aceponate, hydrocortisone
buteprate, hydrocortisone valerate, icomethasone, icomethasone
enbutate, meprednisone, methylprednisolone, mometasone
paramethasone, mometasone furoate monohydrate, prednicarbate,
prednisolone, prednisone, tixocortol, tixocortol pivalate,
triamcinolone, triamcinolone acetonide, triamcinolone alcohol and
their respective pharmaceutically acceptable derivatives, and
combinations thereof. 4. A steroid for use of any preceding clause
which is susceptible to first pass metabolism. 5. A steroid for use
of clause 4 which is selected from budesonide, flunisolide,
fluticasone proprionate, rimexolone, butixocort, tixocortol and
beclomethasone and the salts, esters, conjugates and prodrugs
thereof. 6. A steroid for use of clause 1 or clause 2 which is
budesonide, or a prodrug, ester or conjugate thereof. 7. A steroid
for use of any preceding clause which is dissolved in a liquid or
in a wax which has a melting temperature of no more than 37.degree.
C. 8. A steroid for use of clause 7 wherein the liquid or wax
comprises a macrogol ester. 9. A steroid for use of clause 8
wherein the macrogol ester is macrogol-15-hydroxystearate. 10. A
steroid for use of clause 7 wherein the liquid comprises a medium
chain triglyceride. 11. A steroid for use of any preceding clause
which is comprised in an oral formulation adapted to release the
steroid at least in the colon. 12. A steroid for use of any
preceding clause which is comprised in an oral formulation adapted
to release the steroid at least in the ileum. 13. A steroid for use
of any preceding clause which is comprised in an oral formulation
adapted to release the steroid at least in the duodenum. 14. A
steroid for use of any of clauses 1 to 6 which is comprised in an
immediate release formulation. 15. A steroid for use of any
preceding clause which is in solution in a controlled release
formulation. 16. A steroid for use of any of any preceding clause
wherein the controlled release formulation is a multiple minibead
formulation. 17. A steroid for use of clause 16 wherein the
minibeads comprise a water soluble polymer matrix having dispersed
therein the steroid. 18. A steroid for use of any of clauses 1 to
15 wherein the steroid is comprised in a formulation obtainable by
a process comprising: [0386] (i) dissolving a water-soluble polymer
in water to form an aqueous solution; [0387] (ii) dissolving or
dispersing the steroid in a liquid which will mix with the water to
form a colloid to form a steroid solution or dispersion; [0388]
(iii) mixing the aqueous solution and the steroid solution or
dispersion to form a colloid; [0389] (iv) ejecting the colloid
through a nozzle to form droplets; and [0390] (v) causing or
allowing the water-soluble polymer to gel or form a solid. 19. A
steroid for use of any of clauses 1 to 15 wherein the steroid is
comprised in a formulation obtainable by a process comprising:
[0391] (a) dissolving in water a water-soluble polymer and
dissolving or dispersing in the water a steroid to form a solution
or dispersion; [0392] (b) ejecting the solution or dispersion
through a nozzle to form droplets; and [0393] (c) causing or
allowing the water-soluble polymer to gel or form a solid, the
process optionally further comprising between steps (a) and (b) a
step (b1): [0394] (b1) mixing the solution or dispersion and a
liquid which will mix with water to form a colloid, thereby to form
a colloid. 20. A steroid for use of any preceding clause for use in
combination therapy with one, two or three of active agents (a),
(b) and (c) below: [0395] (a) an immunosuppressant; [0396] (b) a
promoter of the expression or activity of HIF, for example a
hydroxylase inhibitor; [0397] (c) another anti-fibrotic agent. 21.
A steroid for use of any of clauses 1 to 19 for use in combination
therapy with the following active agent(s): [0398] (i) cyclosporin
A; or [0399] (ii) DMOG; or [0400] (iii) hydralazine; or [0401] (iv)
cyclosporin A and DMOG; or [0402] (v) cyclosporin A and
hydralazine. 22. A steroid for use of clause 20 or clause 21
wherein the steroid and the active agent or agents with which the
steroid is for use in combination therapy are all comprised in a
fixed combination. 23. A steroid for use of any preceding clause
which is for use in treating a patient having at least one disease
selected from an inflammatory bowel disease and an enteropathy. 24.
A steroid for use of any preceding clause wherein the treatment is
to inhibit, delay and/or reduce progression and/or initiation of
intestinal fibrosis. 25. A method for treating intestinal fibrosis
in a subject, comprising enterally administering a steroid to the
subject. 26. A method of clause 25 wherein the steroid is
administered orally. 27. A method of clause 25 or clause 26 wherein
the steroid is selected from aclometasone, aclometasone
dipropionate, aldosterone, amcinonide, beclomethasone,
beclomethasone dipropionate, betamethasone, betamethasone
dipropionate, betamethasone sodium phosphate, betamethasone
valerate, budesonide, clobetasone, clobetasone butyrate, clobetasol
propionate, cloprednol, cortisone, cortisone acetate, cortivazol,
deoxycortone, desonide, desoximetasone, dexamethasone,
dexamethasone sodium phosphate, dexamethasone isonicotinate,
difluorocortolone, fluclorolone, flumethasone, flunisolide,
fluocinolone, fluocinolone acetonide, fluocinonide, fluocortin
butyl, fluorocortisone, fluorocortolone, fluocortolone caproate,
fluocortolone pivalate, fluorometholone, fluprednidene,
fluprednidene acetate, flurandrenolone, fluticasone, fluticasone
propionate, halcinonide, hydrocortisone, hydrocortisone acetate,
hydrocortisone butyrate, hydrocortisone aceponate, hydrocortisone
buteprate, hydrocortisone valerate, icomethasone, icomethasone
enbutate, meprednisone, methylprednisolone, mometasone
paramethasone, mometasone furoate monohydrate, prednicarbate,
prednisolone, prednisone, tixocortol, tixocortol pivalate,
triamcinolone, triamcinolone acetonide, triamcinolone alcohol and
their respective pharmaceutically acceptable derivatives, and
combinations thereof. 28. A method of any of clauses 25 to 27
wherein the steroid is susceptible to first pass metabolism. 29. A
method of clause 28 wherein the steroid is selected from
budesonide, flunisolide, fluticasone proprionate, rimexolone,
butixocort, tixocortol and beclomethasone and the salts, esters,
conjugates and prodrugs thereof. 30. A method of clause 25 or
clause 26 wherein the steroid is budesonide, or a prodrug, ester or
conjugate thereof. 31. A method of any of clauses 25 to 30 wherein
the steroid is dissolved in a liquid or in a wax which has a
melting temperature of no more than 37.degree. C. 32. A method of
clause 31 wherein the liquid or wax comprises a macrogol ester. 33.
A method of clause 32 wherein the macrogol ester is
macrogol-15-hydroxystearate. 34. A method of clause 31 wherein the
liquid comprises a medium chain triglyceride. 35. A method of any
of clauses 25 to 34 wherein the steroid is comprised in an oral
formulation adapted to release the steroid at least in the colon.
36. A method of any of clauses 25 to 35 wherein the steroid is
comprised in an oral formulation adapted to release the steroid at
least in the ileum. 37. A method of any of clauses 25 to 36 wherein
the steroid is comprised in an oral formulation adapted to release
the steroid at least in the duodenum. 38. A method of any of
clauses 25 to 34 wherein the steroid is comprised in an immediate
release formulation. 39. A method of any of clauses 25 to 34
wherein the steroid is in solution in a controlled release
formulation. 40. A method of any of clauses 25 to 39 formulation is
a multiple minibead formulation. 41. A method of clause 40 wherein
the minibeads comprise a water soluble polymer matrix having
dispersed therein the steroid. 42. A method of any of clauses 25 to
39 wherein the steroid is comprised in a formulation obtainable by
a process comprising: [0403] (i) dissolving a water-soluble polymer
in water to form an aqueous solution; [0404] (ii) dissolving or
dispersing the steroid in a liquid which will mix with the water to
form a colloid to form a steroid solution or dispersion; [0405]
(iii) mixing the aqueous solution and the steroid solution or
dispersion to form a colloid; [0406] (iv) ejecting the colloid
through a nozzle to form droplets; and [0407] (v) causing or
allowing the water-soluble polymer to gel or form a solid. 43. A
method of any of clauses 25 to 39 wherein the steroid is comprised
in a formulation obtainable by a process comprising: [0408] (a)
dissolving in water a water-soluble polymer and dissolving or
dispersing in the water a steroid to form a solution or dispersion;
[0409] (b) ejecting the solution or dispersion through a nozzle to
form droplets; and [0410] (c) causing or allowing the water-soluble
polymer to gel or form a solid, the process optionally further
comprising between steps (a) and (b) a step (b1): [0411] (b1)
mixing the solution or dispersion and a liquid which will mix with
water to form a colloid, thereby to form a colloid. 44. A method of
clause 42 or clause 43 which further comprises drying the solid.
45. A method of any of clauses 25 to 44 which further comprises
administering to the subject one, two or three of active agents
(a), (b) and (c) below: [0412] (a) an immunosuppressant; [0413] (b)
a promoter of the expression or activity of HIF, for example a
hydroxylase inhibitor; [0414] (c) another anti-fibrotic agent. 46.
A method of any of clauses 25 to 44 which further comprises
administering to the subject the following active agent(s): [0415]
(i) cyclosporin A; or [0416] (ii) DMOG; or [0417] (iii)
hydralazine; or [0418] (iv) cyclosporin A and DMOG; or [0419] (v)
cyclosporin A and hydralazine. 47. A method of clause 45 or clause
46 wherein the steroid and the further active agent or agents are
all comprised in a fixed combination. 48. A method of clause 45 or
clause 46 wherein the steroid and the further active agent or
agents are administered simultaneously, separately or sequentially.
49. A method of any of clauses 25 to 48 wherein the subject has at
least one disease selected from an inflammatory bowel disease and
an enteropathy, and combinations thereof. 50. A method of any of
clauses 25 to 49 wherein the treatment is to inhibit, delay and/or
reduce progression and/or initiation of intestinal fibrosis.
EXAMPLES
Example 1--Manufacturing of Budesonide Minibeads Containing
Kolliphor HS15
Preparation of the Dispersed Phase
[0420] Budesonide is dissolved in Kolliphor HS 15 under constant
stirring at a concentration ranging from 1.19 to 1.88% w/w until a
clear solution is obtained. The temperature is kept at 40.degree.
C. to maintain Solutol HS 15 liquid.
Preparation of the Aqueous Phase
[0421] The components of the aqueous phase are added to water,
which is then heated up to 60-70.degree. C. The aqueous phase is
stirred constantly until all components are dissolved.
Mixing of the Two Phases
[0422] The dispersed phase and the aqueous phase are mixed at a 1:7
or 1:12 w/w ratio. The resulting mixture is stirred at
60-70.degree. C. to achieve homogeneity. The homogeneous solution
was ejected through a pipette, having a single orifice, to form
droplets which fall into a cooling oil medium (a capric/caprylic
triglyceride marketed as Miglyol 810N) at 8-10.degree. C.
[0423] After approximately 30 minutes within the cooling oil
medium, beads are recovered, centrifuged to eliminate excess oil
and then dried at room temperature. Examples of beads obtained by
this method are now given.
[0424] Budesonide Minibeads Containing Kolliphor HS15
Example 2
[0425] A summary of the formulations prepared is presented in Table
1 below:
TABLE-US-00004 TABLE 1 Dispersed phase to Dispersed Aqueous Aqueous
% phase phase phase Formu- Budesonide Com- Com- ratio Test lation
loaded ponents ponents (w/w) Performed 1 0.5 Solutol HS Gelatin, D-
1:12 Content 15, Sorbitol, Assay SDS. (83.5%), Dissolution 2 0.5
Solutol HS Gelatin, D- 1:12 Content 15, Sorbitol, Assay SDS, NaOH,
(85.4%) HPMCP. 3 0.5 Solutol HS Gelatin, D- 1:12 Content 15,
Sorbitol. Assay (86.9%), in vivo study in fibrosis- induced mice 4
0.5 Solutol HS Gelatin, 1:12 Content 15, Glycerin Assay (77.8%) 5
0.5 Solutol HS Gelatin, D- 1:12 Content 15, Sorbitol, Assay NaOH,
(87.6%) HPMCP. 6 0.5 Solutol HS Gelatin, D- 1:7 Content 15,
Sorbitol. Assay (84.4%)
Example 3
[0426] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Table 1,
Formulation 1 are indicated the table below.
TABLE-US-00005 Composition % w/w Budesonide 0.5 D-Sorbitol 5.8 SDS
4.1 Gelatin 60.5 Solutol HS 15 29.1
[0427] These minibeads were submitted to an in vitro dissolution
test performed in distilled water containing 0.2% w/v SDS. The
percent release of budesonide over time for the dissolution test
are shown in Table 2 below.
TABLE-US-00006 TABLE 2 Timepoint % Budesonide (mm) released 30 72.8
60 83.4 80 84.6 100 84.8 150 85.1
Example 4
[0428] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Table 1,
Formulation 2 are indicated in the table below.
TABLE-US-00007 Composition (dry basis) % w/w Budesonide 0.5 NaOH
1.0 HPMCP 9.9 D-Sorbitol 5.2 SDS 3.9 Gelatin 53.4 Solutol HS 15
26.2
Example 5
[0429] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Table 1,
Formulation 3 are indicated in the table below. These beads are
uncoated.
TABLE-US-00008 Composition (dry basis) % w/w Budesonide 0.50
D-Sorbitol 5.4 Gelatin 63.4 Solutol HS 15 30.8
Example 6
[0430] The beads of Example 5 were coated with Surelease.TM. and
pectin (98:2 ratio Surelease:pectin) to have the following weight
percentage amounts of the dry materials.
TABLE-US-00009 Composition (dry basis) % w/w Budesonide 0.5
D-Sorbitol 5.0 Gelatin 58.3 Solutol HS 15 28.3 Surelease 7.8 Pectin
0.2
[0431] The coated beads of Example 6 were used in the mouse model
of fibrosis of Example 12.
Example 7
[0432] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Table 1,
Formulation 4 are indicated in the table below.
TABLE-US-00010 Composition (dry basis) % w/w Budesonide 0.5
Glycerin 5.5 Gelatin 63.6 Solutol HS 15 30.3
Example 8
[0433] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Table 1,
Formulation 5 are indicated in the table below.
TABLE-US-00011 Composition (dry basis) % w/w Budesonide 0.5 NaOH
1.1 HPMCP 10.2 D-Sorbitol 5.2 Gelatin 56.1 Solutol HS 15 26.9
Example 9
[0434] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Table 1,
Formulation 6 are indicated in the table below.
TABLE-US-00012 Composition (dry basis) % w/w Budesonide 0.5
D-Sorbitol 4.4 Gelatin 52.1 Solutol HS 15 42.9
Example 10
[0435] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Formulation 7
are indicated in the table below.
TABLE-US-00013 Composition (dry basis) % w/w Budesonide 0.5
D-Sorbitol 5.9 SDS 4.1 Gelatin 60.4 Solutol HS 15 29.1
[0436] Budesonide Minibeads without Kolliphor HS15
Example 11
[0437] The minibeads of Example 11 were prepared according to the
method of Example 1 except the aqueous phase contained gelatin,
D-Sorbitol and SDS and the dispersed phase contained budesonide,
Transcutol P, Miglyol 810N and Cremophor EL.
[0438] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Example 11 are
indicated in the table below.
TABLE-US-00014 Composition (dry basis) % w/w Budesonide 0.5
D-Sorbitol 5.9 SDS 4.2 Gelatin 60.3 Transcutol P 16.1 Miglyol 810N
4.4 Cremophor EL 8.8
Example 12--Mouse Model of Fibrosis
[0439] The effectiveness of minicapsules of Example 6 on
controlling clinical manifestations of fibrosis was investigated
using a mouse model of colitis.
[0440] The animal model uses dextran sodium sulphate (DSS) to
induce inflammation of the colon, followed by a recovery phase to
allow the development of fibrosis. The DSS induced model for
studying fibrosis is reported in "Analysis of intestinal fibrosis
in chronic colitis in mice induced by dextran sulfate sodium"
(Kenji Suzuki et al Pathology International 2011; 61: 228-238).
C57/B16 female mice (10-12 weeks old) were used in the study. There
were 4 test groups of mice: [0441] Healthy control--mice in this
group were not administered with DSS or budesonide minispheres;
[0442] DSS no recovery--mice in this group were administered with
2.5% DSS in drinking water for 5 days and sacrificed at the end of
DSS dosing (Day 5); [0443] DSS recovery--mice in this group were
administered with 2.5% DSS in drinking water for 5 days and allowed
to recover naturally without receiving any budesonide; [0444] DSS
recovery Bud--mice in this group were administered with 2.5% DSS in
drinking water for 5 days and allowed to recover with treatment
with 2 minispheres of Example 6. The 2 minispheres were
administered orally using a stainless steel oral gavage needle
along with 0.1 ml saline using standard 1 ml syringe.
[0445] The weight change of each test group was recorded throughout
the experiment. FIG. 1 shows the weight change of each test group
as a percentage of their original weight. It can be seen from FIG.
1 that all three test groups given DSS rapidly lost weight with all
three groups experiencing a very similar weight change when the DSS
administration was stopped at day 5. After DSS administration was
stopped and budesonide minicapsules were administered there was a
nearly immediate improvement in the weight of the test group given
budesonide (DSS 2.5% recovery Bud). In contrast the test group
allowed to recover naturally (DSS 2.5% recovery) had a delayed
recovery and continued to lose weight after the DSS had stopped
being administered. Furthermore, the test group given budesonide
(DSS 2.5% recovery Bud) recovered to a higher percentage of their
original weight compared to the natural recovery group (DSS 2.5%
recovery).
[0446] To measure induction of inflammation and to monitor disease
progression, the disease activity index (DAI) is determined. The
DAI is calculated as the sum of scores of weight loss, stool
consistency and blood in faeces. Scoring of the disease activity
index is shown in Table 3.
[0447] Normal stool=formed pellets
[0448] loose stool=pasty and semiformed stool which do not stick to
the anus
[0449] diarrhoea=liquid stools that stick to the anus.
TABLE-US-00015 TABLE 3 Score Weight loss Stool consistency Blood in
feces 0 None Normal None 1 1-5% 2 5-10% Loose Hemoccult + 3 10-20%
4 >20% Diarrhoea Gross bleeding
[0450] A graph of the DAI values the 4 test groups for the duration
of the experiment is shown in FIG. 2. It can be seen from FIG. 2
that the three test groups that were administered with DSS had
progressively worse DAI scores as the DSS administration continued.
As in the weight change graph of FIG. 1 where the weight change was
similar when DSS administration was stopped, the DAI values were
very similar in all three test groups when DSS administration was
stopped. A much quicker reduction in the DAI score was observed for
mice treated with budesonide, the DSS 2.5% recovery--Bud group,
compared with mice in the natural recovery group (DSS 2.5%
recovery).
[0451] The weight change data and disease activity data shown in
FIGS. 1 and 2 shows that DSS causes a negative effect on the tested
mice which is more rapidly counteracted when the mouse is
administered with budesonide, as opposed to allowing natural
recovery.
[0452] At the end of the experiment, the mice were euthanized by
standard cervical dislocation. The following examinations of the
colon were carried out: [0453] Colon weight--the colon is emptied
of the fecal matter and weight of each colon was recorded; [0454]
Colon length--the length of each colon was recorded; and [0455]
Colon histology--approximately 10 mm of mid-colon is fixed in 10%
buffered formaline and paraffin embedded. 4 .mu.m sections were
stained with Hematoxyline and Eosin stain to determine the degree
of inflammation and Masson trichrome stain for evaluation of
fibrosis by measurement of Collagen III. The stained sections were
examined under light microscopy.
[0456] Colon weight is an indicator of colon health. A healthy
colon will weigh less than an unhealthy colon which has become
inflamed and fibrotic. The results of the analysis of colon weight
of the test groups are shown in FIG. 3. The colon weight in mg is
shown for each test group.
[0457] Colon length is also an indicator of colon health. A healthy
colon is longer than an unhealthy colon, as is evident by comparing
the colon length of the No DSS group against the colon length of
the three groups administered with DSS in FIG. 4. The colon weight
and colon length results also suggest that treatment with
budesonide is effective in the 14 day recovery period.
[0458] FIGS. 5 to 8 show colon histology of each test group stained
with Hematoxyline and Eosin. The colon histology of the healthy
control specimens show a healthy colon (FIG. 5). In contrast, the
mice that were euthanised at Day 5 and did not have any recovery
time (DSS 2.5% no recovery) show a damaged colon with a thickened
submucosa and irregular epithelial structure (FIG. 6). The two test
groups that were allowed to recover for 14 days, DSS 2.5% recovery
(FIG. 7) and DSS 2.5% recovery--Bud (FIG. 8), displayed improved
colonic health with a reduction in the colonic wall thickness and
an ordered mucosa. (Note that the term "Bud" refers to budesonide).
The histology of colonic tissues suggests that treatment with
budesonide is effective at treating fibrosis in the 14 day recovery
period.
[0459] FIG. 9 indicates the amount of collagen type III in the
histological samples. Collagen type III level is an important
indicator in the fibrosis model. Data from a study on collagen type
III synthesis by fibroblasts isolated from patients' strictures
resulting from Crohn's disease provides evidence that the different
reactivity of mesenchymal cells to cytokines in terms of
synthesizing type III collagen fibrils, which is a major component
of collagen fibrils, may play an important role in the pathogenesis
of fibrosis and stricture formation in chronic inflammatory bowel
diseases.
[0460] The levels of collagen III in the group treated with
budesonide are lower than the collagen III levels in the natural
recovery group (DSS recovery) with statistical significance
(unpaired t-test, one-tailed--95% confidence interval). The
collagen levels are also statistically significantly lower for the
healthy control and DSS no recovery groups compared to the DSS
recovery group.
[0461] The above result shows that there is a statistically
significant difference when comparing the collagen type III level
in a budesonide treated group with the DSS recovery group.
Therefore, the conclusion that budesonide has a beneficial effect
against fibrosis can be drawn.
Example 13--Preparation of Budesonide and Cyclosporin A
Minicapsules
[0462] The minibeads of Example 13 were prepared according to the
method of Example 1 except the aqueous phase contained gelatin,
D-Sorbitol and SDS and the dispersed phase contained budesonide,
cyclosporin A, Transcutol P, Miglyol 810N and Cremophor EL.
[0463] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Example 13 are
indicated in the table below.
TABLE-US-00016 Composition (dry basis) % w/w Cyclosporine 10.1
Budesonide 0.8 Transcutol P 16.6 Cremophor EL 9.3 Miglyol 810 N 4.6
Gelatin 48.7 D-Sorbitol 5.7 SDS 4.3
Example 14
[0464] The minicapsules of Example 13 were coated with 5.9% weight
gain of a Surelease/pectin mixture (98:2 ratio of Surelease:pectin)
to give a weight percentage amount of the dry materials as shown in
the table below.
TABLE-US-00017 Composition (dry basis) % w/w Cyclosporine 9.5
Budesonide 0.7 Transcutol P 15.7 Cremophor EL 8.8 Miglyol 810 N 4.3
Gelatin 46.0 D-Sorbitol 5.4 SDS 4.0 Surelease 5.5 Pectin 0.1
Example 15--Preparation of Budesonide and Hydralazine
Minicapsules
[0465] The minibeads of Example 15 were prepared according to the
method of Example 1 except the aqueous phase contained hydralazine,
gelatin, D-Sorbitol and SDS and the dispersed phase contained
budesonide, Transcutol P, Miglyol 810N and Cremophor EL.
[0466] The weight percentage amounts of the dry materials
introduced into the process to form the minibeads of Example 13 are
indicated in the table below.
TABLE-US-00018 Composition (dry basis) % w/w Hydralazine 10.2
Budesonide 0.8 Transcutol P 16.8 Miglyol 810N 4.7 Cremophor EL 9.2
Gelatin 49.5 D-Sorbitol 5.0 SDS 3.8
Example 16
[0467] The minicapsules of Example 15 were coated with 5.1% weight
gain of a Surelease/pectin (98:2 ratio of Surelease:pectin) mixture
to give a weight percentage amount of the dry materials as shown in
the table below.
TABLE-US-00019 Composition (dry basis) % w/w Hydralazine 9.7
Budesonide 0.8 Transcutol P 16.0 Miglyol 810N 4.5 Cremophor EL 8.7
Gelatin 47.1 D-Sorbitol 4.8 SDS 3.6 Surelease 4.8 Pectin 0.1
Example 17--Mouse Model of Fibrosis
[0468] The coated budesonide and cyclosporin A minicapsules of
Example 14 and the budesonide and hydralazine minicapsules of
Example 16 were investigated for effectiveness in controlling
clinical manifestations of intestinal fibrosis using a mouse model
of colitis.
[0469] The animal model was the same as the model used in Example
12 using dextran sodium sulphate (DSS) to induce inflammation of
the colon, followed by a recovery phase to allow the development of
fibrosis. C57/B16 female mice (10-12 weeks old) were used in the
study. There were 4 test groups of mice: [0470] Healthy
control--mice in this group were not administered with DSS or
budesonide minispheres; [0471] DSS no recovery--mice in this group
were administered with 2.5% DSS in drinking water for 5 days and
sacrificed at the end of DSS dosing (Day 5); [0472] DSS
recovery--mice in this group were administered with 2.5% DSS in
drinking water for 5 days and allowed to recover naturally without
receiving any budesonide; and [0473] DSS recovery with
administration of a test formulation--mice in this group were
administered with 2.5% DSS in drinking water for 5 days and allowed
to recover with treatment with 2 minispheres of a test formulation.
The 2 minispheres were administered orally using a stainless steel
oral gavage needle along with 0.1 ml saline using standard 1 ml
syringe.
[0474] There were four test formulations that were administered to
mice. The four test formulations are given below: [0475] DSS
recovery--Bud+CyA (uncoated)--minicapsules of Example 13; [0476]
DSS recovery--Bud+CyA (coated)--minicapsules of Example 14; [0477]
DSS recovery--Bud+HyA (uncoated)--minicapsules of Example 15; and
[0478] DSS recovery--Bud+HyA (coated)--minicapsules of Example
16.
[0479] Each of the four test formulations was compared to the
healthy control, DSS no recovery and the DSS recovery test groups
for DAI scores, colon histology, submucosal collagen type I levels
and submucosal collagen type III levels.
[0480] To measure induction of inflammation and to monitor disease
progression, the disease activity index (DAI) was determined, as
explained above for Example 12.
[0481] A graph of the DAI values of each of the four test
formulations correlated against the healthy control, DSS no
recovery and the DSS recovery test groups for the duration of the
experiment is shown in FIGS. 10 to 13.
[0482] FIG. 10 shows the DAI scores of the test formulation
containing a combination of budesonide and cyclosporin in uncoated
minicapsules (Example 13). When administration of DSS is stopped
and administration of the test formulation starts there is a rapid
reduction in the DAI score, whereas a delayed reduction of the DAI
was seen in the natural recovery test group. The same minicapsules
coated with Surelease/pectin (Example 14) produced a similar
reduction in the DAI to the natural recovery test group (FIG. 11).
However, the final DAI score for the DSS recovery--Bud+CyA (coated)
test group was lower than the natural recovery group.
[0483] FIG. 12 and FIG. 13 show plots of the DAI scores for the DSS
recovery--Bud+HyA (uncoated) and DSS recovery--Bud+HyA (coated)
test formulation respectively. The coated budesonide and
hydralazine test formulation (Example 16) showed improved DAI
scores over the natural recovery test group.
[0484] At the end of the experiment, the mice were euthanized by
standard cervical dislocation and examinations of the colon
histology were carried out. Approximately 10 mm of mid-colon was
fixed in 10% buffered formaline and paraffin embedded. 4 .mu.m
sections were stained with Masson trichrome stain for evaluation of
fibrosis by measurement of submucosal collagen I and submucosal
collagen III. The stained sections were examined under light
microscopy.
[0485] FIG. 14 shows colon histology of each test group stained
with Masson trichrome. This stain colors collagen and gives
different types of colagen different colours. In this experiment
collagen type I and type II were of interest and these two types of
collagen are stained red and green respectively. The colon
histology of the healthy control specimens show a healthy colon
with submucosal colloagen. In contrast, the mice that were
euthanised at Day 5 and did not have any recovery time (DSS 2.5% no
recovery) show a distended submucosal layer with prolific levels of
collagen. The test group that was allowed to recover naturally for
14 days displays improved colonic health with a thinner submucosal
layer. The histology of the colon of mice in the test groups that
received one of the test formulations also showed an improvement in
colonic health with a noticeably thinner submucosa.
[0486] The colon histology was then examined under light microscopy
and the levels of collagen type I and type II were quantified to
give the bar charts in FIGS. 15 and 16. FIG. 15 shows the levels of
collagen type I for each of the test groups and each of the test
formulations. It is immediately apparent from this data that
collagen I levels in the test groups given one of the test
formulations are comparable with the collagen levels in the healthy
control. In contrast, the test groups that were not allowed to
recovery and the test group that recovered naturally have a higher
level of collagen I than the healthy control and the test groups
given one of the four test formulations. Interestingly, the healthy
recovery test group has virtually the same level of collagen I as
the test group that was not allowed to recover. This implies that
collagen levels are not reduced when recovery is allowed to
progress naturally, although the test group showed an improvement
in DAI; therefore, fibrosis is not affected by natural recovery.
However, each of the test formulations reduced the collagen I
levels to a comparable level to the healthy control.
[0487] This clearly shows that the test formulations are effective
at reducing collagen I levels which have been raised by
inflammation and the test formulation are effective treatments of
fibrosis.
[0488] FIG. 16 shows the levels of collagen type III for each of
the test groups and each of the test formulations. As in the
results for collagen I, in the test group that was not allowed to
recover (DSS no recovery) and the test group allowed to recover
naturally (DSS recovery) the level of collagen III increased
compared to the healthy control. Interestingly, in this case the
DSS recovery group had higher levels of collagen III than the DSS
no recovery group. This implies that collagen III synthesis may
continue after the DSS administration is stopped, and the source of
inflammation is removed. It can be concluded that allowing recovery
to occur naturally does not have any beneficial effect on the level
of collagen II and hence fibrosis. In contrast to the DSS recovery
group and relative thereto, the test groups given one of the four
test formulations showed a reduced level of collagen III. The test
groups treatment with uncoated budesonide+cyclosporin, Example 13,
coated budesonide+cyclosporin, Example 14, and uncoated
budesonide+hydralazine, Example 15, gave a level of collagen III
comparable to the healthy control.
[0489] In the same way that the collagen I data does; this data
clearly shows that the test formulations are effective at reducing
collagen III levels, especially for the formulations of Examples
13-15, which have been raised by inflammation. Therefore, the test
formulation are effective treatments of fibrosis.
[0490] Suggest inclusion of other DSS data here. I believe that
there is a strong enough correlation between short term DSS studies
and the recovery model to support examples of other drugs with
anti-fibrotic efficacy, assuming that fibrosis is a complication
associated with inflammation, regardless of cause.
Example 17--Aspect Ratio
[0491] Minibeads were made generally following the procedure of
Example 1 by extrusion from a nozzle to fall into a cooling medium.
Some of the minibeads were then coated as described herein with a
Surelease.TM. and pectin mixture. Sample populations of the coated
minibeads and sample populations of uncoated minibeads were both
typically found to have an average aspect ratio of 1.2 when
measured using an Eyecon.TM. particle characteriser.
* * * * *
References