U.S. patent application number 17/198733 was filed with the patent office on 2021-09-02 for peptide slow-release formulations.
This patent application is currently assigned to CAMURUS AB. The applicant listed for this patent is CAMURUS AB. Invention is credited to Fredrik JOABSSON, Markus JOHNSSON, Catalin NISTOR, Krister THURESSON, Fredrik TIBERG.
Application Number | 20210268112 17/198733 |
Document ID | / |
Family ID | 1000005585129 |
Filed Date | 2021-09-02 |
United States Patent
Application |
20210268112 |
Kind Code |
A1 |
JOHNSSON; Markus ; et
al. |
September 2, 2021 |
PEPTIDE SLOW-RELEASE FORMULATIONS
Abstract
A composition for the delayed delivery of a peptide active agent
comprising; i) a salt of said peptide active agent comprising at
least one positively charged peptide ion and at least one
negatively charged counter-ion ii) a sustained-release delivery
vehicle, wherein the at least one negatively charged counter-ion is
a halide ion, preferably a chloride or bromide ion.
Inventors: |
JOHNSSON; Markus; (Lund,
SE) ; JOABSSON; Fredrik; (Lund, SE) ; NISTOR;
Catalin; (Lund, SE) ; THURESSON; Krister;
(Lund, SE) ; TIBERG; Fredrik; (Lund, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CAMURUS AB |
Lund |
|
SE |
|
|
Assignee: |
CAMURUS AB
Lund
SE
|
Family ID: |
1000005585129 |
Appl. No.: |
17/198733 |
Filed: |
March 11, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15983262 |
May 18, 2018 |
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17198733 |
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12664835 |
Apr 6, 2010 |
9974861 |
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PCT/GB2008/002035 |
Jun 13, 2008 |
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15983262 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 47/10 20130101;
A61K 47/14 20130101; A61K 38/31 20130101; A61K 9/0019 20130101;
A61K 9/08 20130101; A61K 47/34 20130101; A61K 47/24 20130101; A61K
47/08 20130101 |
International
Class: |
A61K 47/34 20060101
A61K047/34; A61K 38/31 20060101 A61K038/31; A61K 9/00 20060101
A61K009/00; A61K 9/08 20060101 A61K009/08; A61K 47/10 20060101
A61K047/10; A61K 47/14 20060101 A61K047/14; A61K 47/24 20060101
A61K047/24; A61K 47/08 20060101 A61K047/08 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 15, 2007 |
GB |
0711656.9 |
Claims
1-37. (canceled)
38. A method for the treatment of a human or non-human mammalian
subject in need thereof with a somatostatin analogue, comprising
administering to the subject a pre-formulation comprising a
low-viscosity mixture of: a) at least one diacyl glycerol; b) at
least one phosphatidyl choline (PC); c) at least one oxygen
containing organic solvent; and d) at least one halide salt of at
least one somatostatin analogue selected from lanreotide and
vapreotide; wherein the pre-formulation forms, or is capable of
forming, at least one liquid crystalline phase structure upon
contact with an aqueous fluid.
39. The method of claim 38, wherein component a) comprises glycerol
dioleate (GDO).
40. The method of claim 38, wherein component b) comprises soy
PC.
41. The method of claim 38, wherein component c) comprises
ethanol.
42. The method of claim 38, wherein the halide salt is a chloride
or bromide ion.
43. The method of claim 38, wherein the pre-formulation comprises:
a) 40-70 wt % of the at least one diacyl glycerol; b) 30-60 wt % of
the at least one phosphatidyl choline (PC); and c) 0.1-20 wt % of
the at least one oxygen containing organic solvent.
44. The method of claim 38, wherein components a) and b) are
present in a ratio of a:b of 40:60 to 70:30.
45. The method of claim 38, wherein the pre-formulation comprises:
a) 40-70 wt % of glycerol dioleate (GDO); b) 30-60 wt % of soy PC;
c) 0.1-20 wt % of ethanol; and d) 0.1-10 wt % of the at least one
halide salt of at least one somatostatin analogue selected from
lanreotide and vapreotide; wherein the halide salt is a chloride or
bromide ion, wherein components a) and b) are present in a ratio of
a:b of 40:60 to 70:30.
46. The method of claim 45, wherein the pre-formulation comprises:
a) 43-60 wt % of glycerol dioleate (GDO); b) 35-55 wt % of soy PC;
and c) 0.1-10 wt % of ethanol, wherein components a) and b) are
present in a ratio of a:b of 45:55 to 60:40.
47. The method of claim 46, wherein the pre-formulation comprises:
a) 45-55 wt % of glycerol dioleate (GDO); b) 40-50 wt % of soy PC;
and c) 2-8 wt % of ethanol; wherein components a) and b) are
present in a ratio of a:b of 48:52 to 55:45.
48. The method of claim 38, wherein the method of treatment is a
method for the treatment of at least one condition selected from
acromegaly, cancers, carcinomas, melanomas, tumours expressing at
least one somatostatin receptor, somatostatin receptor-2-positive
tumours, somatostatin receptor-5-positive tumours, prostate
cancers, gastro-entero-pancreatic neuroendocrine tumours, carcinoid
tumours, insulinomas, gastrinomas, vasoactive intestinal
peptide--producing-tumours and glucagonomas, elevated growth
hormone, elevated insulin-like growth factor I, varicial bleeding,
chemotherapy induced gastro intestinal problems, lymphorrhea,
diabetic retinopathy, thyroid eye disease, obesity, pancreatitis,
and related conditions.
49. The method of claim 38, comprising administration by i.m., s.c.
or preferably deep s.c. injection.
50. The method of claim 38, comprising administration by a
pre-filled administration device.
51. The method of claim 38, comprising a single administration
every 20 to 180 days.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation application of U.S.
application Ser. No. 15/983,262, filed on May 18, 2018, which is a
Continuation of U.S. application Ser. No. 12/664,835, filed on Dec.
14, 2009, now patented as U.S. Pat. No. 9,974,861; which is a 371
application of International Application No. PCT/GB2008/002035,
filed on Jun. 13, 2008, which claims priority to United Kingdom
Application NO. 0711656.9, filed on Jun. 15, 2007; all of which are
incorporated herein by reference.
SEQUENCE LISTING
[0002] The Sequence Listing submitted herewith is an ASCII text
file (2021-03-11 Sequence Listing.text, created on Mar. 5, 2021,
2090 bytes) via EFS-Web is hereby incorporated by reference.
[0003] The present invention relates to formulation precursors
(pre-formulations) for the in situ generation compositions for the
controlled release of the salts of peptide active agents,
especially of somatostatin analogues. In particular, the invention
relates to pre-formulations of amphiphilic components and at least
one salt of a peptide active agent (e.g. somatostatin analogue) for
parenteral application.
[0004] Many bioactive agents including pharmaceuticals, nutrients,
vitamins and so forth have a "functional window". That is to say
that there is a range of concentrations over which these agents can
be observed to provide some biological effect. Where the
concentration in the appropriate part of the body (e.g. locally or
as demonstrated by serum concentration) falls below a certain
level, no beneficial effect can be attributed to the agent.
Similarly, there is generally an upper concentration level above
which no further benefit is derived by increasing the
concentration. In some cases increasing the concentration above a
particular level results in undesirable or even dangerous
effects.
[0005] Some bioactive agents have a long biological half-life
and/or a wide functional window and thus may be administered
occasionally, maintaining a functional biological concentration
over a substantial period of time (e.g. 6 hours to several days).
In other cases the rate of clearance is high and/or the functional
window is narrow and thus to maintain a biological concentration
within this window regular (or even continuous) doses of a small
amount are required. This can be particularly difficult where
non-oral routes of administration (e.g. parenteral administration)
are desirable since self-administration may be difficult and thus
cause inconvenience and/or poor compliance. In such cases it would
be advantageous for a single administration must provide active
agent at a therapeutic level over the whole period during which
activity is needed. Peptide active agents are particularly suitable
for formulation as sustained release compositions because naturally
occurring peptidase activity typically results in a short half-life
for these actives.
[0006] Somatostatins (Growth Hormone Release Inhibiting Factors,
SSTs) are natural peptide hormones with a wide distribution in
animals, acting as neurotransmitters in the central nervous system,
and having diverse paracrine/autocrine regulatory effects on
several tissues. Two biologically active products are known in
higher species, SST-14 and SST-28, a congener of SST-14 extended at
the N-terminus. SST-14 is a 14 residue cyclic peptide hormone
having the sequence
Ala-Gly-Cys-Lys-Asn-Phe-Phe-Trp-Lys-Thr-Phe-Thr-Ser-Cys, where the
two cysteine residues are connected by a disulphide bridge to
generate a type II n-turn at the key binding sequence of
Phe-Trp-Lys-Thr. The biological half-life of natural SST-14 is very
short (1-3 minutes) and so it is not, in itself, a viable
therapeutic in current formulations, but an increasing number of
somatostatin analogues are becoming available with higher
activities and/or longer clearance times in vivo.
[0007] Somatostatin analogues, such as octreotide, lanreotide,
vapreotide, pasireotide (SOM 230) and related peptides, are used or
indicated in the treatment of a variety of conditions where they
are typically administered over an extended period. Octreotide, for
example, is the synthetic octapeptide with sequence
D-Phe-Cys-Phe-D-Trp-Lys-Thr-Cys-Thr-ol (2-7 disulphide bridge) and
is typically administered as an acetate salt. This SST-14
derivative retains the key Phe-(D)Trp-Lys-Thr n-turn required for
in vivo SST-like activity but, in contrast to the natural hormone,
has a terminal half-life of around 1.7 hours. Octreotide is used in
treatment of conditions including carcinoid tumours and acromegaly,
and is typically administered over a sustained period of weeks, or
more commonly many months or years. Somatostatin analogues are of
particular interest for the treatment of many different types of
cancers since a wide variety of tumours are found to express
somatostatin receptors (SSTRs). There are five known types of SSTRs
(SSTR1-SSTRS), showing equally high affinity for SST-14. The most
investigated somatostatin analogues, including octreotide, show
high selectivity for SSTR2 and SSTRS; thus, octreotide is of
particular interest for the treatment of tumours expressing these
types of receptors.
[0008] The most common "simple" formulation of Octreotide is
"Sandostatin".RTM. from Novartis. This is an aqueous solution for
subcutaneous (s.c) injection, and a 100 .mu.g dose reaches a peak
concentration of 5.2 ng/ml at 0.4 hours post injection. The
duration of action can be up to 12 hours but s.c. dosing is
generally carried out every 8 hours. Evidently, s.c. injection 3
times daily for periods of months or years is not an ideal dosing
regime.
[0009] In order to avoid the need for multiple daily injections of
octreotide, a further formulation is available; "Sandostatin
LAR".RTM., again from Novartis. This is a formulation of octreotide
in poly lactic co-glycolic acid microspheres which, after
resuspension, may be administered by intra muscular (i.m.)
injection.
[0010] All of the known commercially available somatostatin
analogue preparations, especially those having delayed release are
formulated with the peptide active in the form of the acetate
salt.
[0011] Carcinoid tumours are intestinal tumour arising from
specialised cells with paracrine functions (APUD cells). The
primary tumour is commonly developed in the appendix, where it is
clinically benign. Secondary, metastatic, intestinal carcinoid
tumours secrete excessive amounts of vasoactive substances,
including serotonin, histamine, prostaglandins, and polypeptide
hormones. The clinical result is carcinoid syndrome (a syndrome of
episodic cutaneous flushing, cyanosis, abdominal cramps, and
diarrhoea in a patient with valvular heart disease and, less
commonly, asthma and arthropathy). Carcinoid tumours may grow
anywhere in the gastrointestinal tract (and in the lungs) with
approximately 90% originating in the appendix. The remainder occur
in the ileum, stomach, colon or rectum.
[0012] Currently, treatment of carcinoid syndrome starts with i.v.
bolus injection followed by i.v. infusion of Sandostatin. When
sufficient effect on symptoms has been established, treatment with
a depot formulation of octreotide formulated in poly
lactic-co-glycolic acid (PLGA) microspheres is started. However,
during the first two weeks or more after injection of the depot,
daily s.c. injections with Sandostatin are recommended to
compensate for the slow release from the PLGA spheres.
[0013] Acromegaly is a rare chronic and insidious hormonal disorder
that occurs when the pituitary gland produces excess growth hormone
(GH). It most commonly affects middle-aged adults and may lead to
premature death. Diabetes mellitus, hypertension, and increased
risk of cardiovascular disease are the most serious health
consequences of acromegaly. In addition, patients with acromegaly
are at an increased risk of developing colon polyps, which can
become cancerous. The prevalence of acromegaly is approximately 60
cases per million population, and the incidence is 3.3 new cases
per million per year. The word acromegaly comes from the Greek
words for "extremities" (acro) and "great" (megaly), because one of
the most common symptoms of this condition is abnormal growth of
the hands and feet.
[0014] Acromegaly is caused by prolonged overproduction of growth
hormone (GH) and excessive production of insulin-like growth
factor-I (IGF-I). In 98 percent of cases, the overproduction of GH
is caused by a pituitary adenoma. The rate of GH production and the
aggressiveness of the tumour vary from patient to patient.
Generally, more aggressive tumours are seen in younger
patients.
[0015] Treatment of acromegaly is initiated by a period of s.c.
injections three times per day (optimal daily dose=300 .mu.g
octreotide). After the last s.c. dose, and providing a suitable
effect is observed, the treatment with a depot formulation of
octreotide formulated in poly lactic-co-glycolic acid (PLGA)
microspheres is started. Dose adjustments are made after
measurement of biomarkers (GH and IGF-1), typically after around 3
months.
[0016] The existing octreotide slow release formulation relies upon
a well-established in vivo degrading-polymer type of depot
formulation. This is typically a biodegradable polymer containing
poly (lactic acid) (PLA) and/or poly (lactic-co-glycolic acid)
(PLGA) and may be in the form of a solution in an organic solvent,
a pre-polymer mixed with an initiator, encapsulated polymer
particles or (as in the case of octreotide) polymer
microspheres.
[0017] The polymer or polymer particles entrap the active agent and
are gradually degraded releasing the agent by slow diffusion and/or
as the matrix is absorbed. Examples of such systems include those
described in U.S. Pat. Nos. 4,938,763, 5,480,656 and 6,113,943 and
can result in delivery of active agents over a period of up to
several months. These systems do, however, have a number of
limitations including the complexity of manufacturing and
difficulty in sterilising (especially the microsphere formulation).
The local irritation caused by the lactic and/or glycolic acid
which is released at the injection site is also a noticeable
drawback. There is also often quite a complex procedure to prepare
the injection dose from the powder precursor.
[0018] One highly significant drawback of the known PLGA octreotide
depot system is the complexity of preparation for the administering
person. The depot is provided as a powder precursor of the
octreotide-containing microspheres, plus a diluent in which these
must be uniformly suspended. Successful preparation of the depot
system for administration requires a multi-step method which must
be followed precisely in order to ensure that the powder-precursor
is completely saturated and in a uniform suspension prior to
injection. The depot system must then be administered immediately
by a method involving continual rocking of the syringe to maintain
a uniform dispersion up to the point of deep gluteal intramuscular
injection.
[0019] Although simple preparation is a highly advantageous
feature, this must often be weighed against the need for stability
to long term storage. Previously known octreotide depot
compositions such as those based upon PLGA or even previously known
lipid-depot compositions (e.g. WO2006/075124) are not generally
stable to long-term storage, especially at room temperature or
higher. Evidently, it would be an advantage to provide compositions
which not only avoided the need for complex preparation, but could
also be stored in ready-to-use form for extended periods,
especially at room temperature.
[0020] A further limitation of the existing PLGA octreotide depot
systems is that dosing cannot easily be tailored to suit particular
patients. It has recently been proposed that dosing of somatostatin
analogues should be administered relative to the body weight of the
subject since plasma concentrations have shown a marked variability
by subject weight. A depot system comprising a pre-weighted dry
powder which is suspended unstabily in an injection vehicle does
not allow any such control, however, unless a considerable range of
pre-measured doses is to be provided. The suspension cannot be
partially administered because the particles are not evenly
suspended. It would thus be a considerable advantage to have a
homogeneous depot precursor which allowed administration of a dose
to be decided on a subject-specific basis at the time of
administration.
[0021] From a drug delivery point of view, polymer depot
compositions generally have the disadvantage of accepting only
relatively low drug loads and having a "burst/lag" release profile.
The nature of the polymeric matrix, especially when applied as a
solution or pre-polymer, causes an initial burst of drug release
when the composition is first administered. This is followed by a
period of low release, while the degradation of the matrix begins,
followed finally by an increase in the release rate to the desired
sustained profile. This burst/lag release profile can cause the in
vivo concentration of active agent to burst above the functional
window immediately following administration, then drop back through
the bottom of the functional window during the lag period before
reaching a sustained functional concentration. Evidently, from a
functional and toxicological point of view this burst/lag release
profile is undesirable and could be dangerous. It may also limit
the equilibrium concentration which can be provided due to the
danger of adverse effects at the "peak" point.
[0022] In the case of octreotide, the functional window ranges from
around 0.8 to 20+ng/ml, but even so, as indicated above, the use of
PLGA microspheres causes a lag of several weeks during which
"top-up" injections must be provided. Evidently, it would be an
advantage to provide a depot system which achieved a "plateau"
level more quickly. The release of octreotide into rabbits from a
PLGA microsphere product was studied by Comets et al. (J.
Controlled Release 59 (1999) 197-05), for example, and this
indicated the "third phase" release of over 85% of the active agent
began more than 15 days after administration.
[0023] The low loading capacity of polymeric depot products, as
well as the nature of microparticles causes additional problems in
administration. In particular, a relatively high volume, of around
5 ml must be injected in order to carry the microparticle
suspension, and the suspension can easily block syringe needles
(hence the need for adherence to strict administration protocols),
thus requiring that a relatively wide (e.g. 19-gauge) needle be
used. Both of these factors, as well as the need for deep i.m.
injection, result in considerable discomfort to the patient during
administration. It would be a considerable advantage if a depot
system could be provided requiring lower volumes of administration,
which was administrable through a narrower gauge needle, and/or did
not require such deep injections.
[0024] The manufacture of PLGA microbeads is additionally a
considerable difficulty with existing somatostatin analogue depot
systems. In particular, since the beads are particulate, they
cannot be sterile-filtered and furthermore, since the PLGA
copolymer melts at around 40.degree. C., they cannot be
heat-treated for sterility. As a result, a complex manufacturing
process must all be conducted under conditions of high
sterility.
[0025] Even though known lipid depot compositions of somatostatin
analogues overcome many of the problems associated with prior-known
depot compositions, it remains desirable to provide further control
over the dosing and release rate. As indicated above, octreotide
and other somatostatin analogues may be required at stable dosage
levels over long periods, and thus it is of advantage to provide
compositions which will release active agent at an even more
carefully controlled rate and for an even further extended
duration.
[0026] The present inventors have now established that slow-release
compositions of peptide actives, especially somatostatin analogues
are surprisingly more effective if an appropriate counter-ion is
chosen for the salt of the peptide active.
[0027] In a first aspect, the present invention thus provides a
composition for the delayed delivery of a peptide active agent
comprising; [0028] i) a salt of said peptide active agent
comprising at least one positively charged peptide ion and at least
one negatively charged counter-ion [0029] ii) a sustained-release
delivery vehicle.
[0030] Wherein said at least one negatively charged counter-ion is
a halide ion, preferably a chloride or bromide ion.
[0031] Many sustained-release delivery systems exist, and many of
these are appropriate for use in the present invention. For
example, polymer-based slow-release compositions based upon
degradable polymers such as PLGA, poly-lactate or poly-glycolate
are suitable, but most suitable for use in the present invention
are lipid-based depot compositions, such as those described in
WO2005/117830 and/or WO2006/075124, the complete disclosures of
which, along with the disclosures of all documents cited herein,
being hereby incorporated by reference. The formulation of active
agents into biodegradable polymer depot formulations is now well
established and well known in the art, and the peptide salts of the
present invention may thus be formulated with these using known
methods.
[0032] Preferably, the composition of the present invention is
capable of releasing octreotide at a functional concentration for
at least 1 month. Further preferably, the composition is stable to
storage at 25 degrees Celsius or higher for at least 4 weeks
without loss of more than 5% or the original activity of the active
agent. Preferred peptide active agents are somatostatin analogues
as described herein.
[0033] In one preferred aspect of the invention, the composition of
the invention is formed by injection of a low-viscosity lipid
composition which subsequently undergoes a phase-change whereby to
form a slow-release composition. In this aspect, the invention
provides a pre-formulation comprising a low viscosity mixture of:
[0034] a) at least one diacyl glycerol; [0035] b) at least one
phosphatidyl choline; [0036] c) at least one oxygen containing
organic solvent; [0037] d) a salt of at least one somatostatin
analogue comprising at least one positively charged peptide ion and
at least one negatively charged counter-ion wherein the
pre-formulation forms, or is capable of forming, at least one
liquid crystalline phase structure upon contact with an aqueous
fluid and wherein said at least one negatively charged counter-ion
is a halide ion, preferably a chloride or bromide ion.
[0038] Generally, the said aqueous fluid will be a body fluid
particularly extra-vascular fluid, extracellular fluid/interstitial
fluid or plasma, and the pre-formulation will form a liquid
crystalline phase structure when contacted with such a fluid (e.g.
in vivo). The pre-formulation of the invention will generally not
contain any significant quantity of water prior to
administration.
[0039] Preferably the pre-formulation will be in a form suitable
for administration (i.e. without requiring preparation steps which
alter the composition, such as dilution or suspension). It is
furthermore preferable that the pre-formulation (especially where
it is in a form suitable for administration) is stable to storage
at room temperature for at least 1 month, preferably at least 6
months without loss of more than 10%, preferably 5% of the activity
of the active agent before storage.
[0040] In a further aspect of the invention, there is also provided
a method of delivery of a somatostatin analogue to a human or
non-human animal (preferably mammalian) body, this method
comprising parenterally administering (e.g. i.m. or preferably
s.c.) a pre-formulation comprising a low viscosity mixture of:
[0041] a) at least one diacyl glycerol; [0042] b) at least one
phosphatidyl choline; [0043] c) at least one oxygen containing
organic solvent; [0044] d) a salt of at least one somatostatin
analogue comprising at least one positively charged peptide ion and
at least one negatively charged counter-ion; whereby to form at
least one liquid crystalline phase structure upon contact with an
aqueous fluid in vivo following administration and wherein said at
least one negatively charged counter-ion is a halide ion,
preferably a chloride or bromide ion. Preferably, the
pre-formulation administered in such a method is a pre-formulation
of the invention as described herein.
[0045] In a further aspect, the present invention also provides a
method for the preparation of a liquid crystalline depot
composition comprising exposing a pre-formulation comprising a low
viscosity mixture of: [0046] a) at least one diacyl glycerol;
[0047] b) at least one phosphatidyl choline; [0048] c) at least one
oxygen containing organic solvent; and [0049] d) a salt of at least
one somatostatin analogue comprising at least one positively
charged peptide ion and at least one negatively charged
counter-ion; to an aqueous fluid in vivo; wherein said at least one
negatively charged counter-ion is a halide ion, preferably a
chloride or bromide ion.
[0050] Preferably the pre-formulation administered is a
pre-formulation of the present invention as described herein.
[0051] In a still further aspect the present invention provides a
process for the formation of a pre-formulation suitable for the
administration of a bioactive agent to a (preferably mammalian)
subject, said process comprising forming a low viscosity mixture of
[0052] a) at least one diacyl glycerol; [0053] b) at least one
phosphatidyl choline; [0054] c) at least one oxygen containing
organic solvent; and dissolving or dispersing a salt of at least
one somatostatin analogue comprising at least one positively
charged peptide ion and at least one negatively charged counter-ion
in the low viscosity mixture, or in at least one of components a, b
or c prior to forming the low viscosity mixture, wherein said at
least one negatively charged counter-ion is a halide ion,
preferably a chloride or bromide ion. Preferably the
pre-formulation so-formed is a formulation of the invention as
described herein.
[0055] In a yet still further aspect the present invention provides
the use of a low viscosity mixture of: [0056] a) at least one
diacyl glycerol; [0057] b) at least one phosphatidyl choline;
[0058] c) at least one oxygen containing organic solvent; [0059] d)
a salt of at least one somatostatin analogue comprising at least
one positively charged peptide ion and at least one negatively
charged counter-ion; in the manufacture of a pre-formulation for
use in the sustained administration of said somatostatin analogue,
wherein said pre-formulation is capable of forming at least one
liquid crystalline phase structure upon contact with an aqueous
fluid and wherein said at least one negatively charged counter-ion
is a halide ion, preferably a chloride or bromide ion.
[0060] In a still further aspect, the present invention provides a
method for the treatment of a human or non-human mammalian subject
in need thereof with a somatostatin analogue, said method
comprising administering to said subject a pre-formulation
comprising a low-viscosity mixture of; [0061] a) at least one
diacyl glycerol; [0062] b) at least one phosphatidyl choline;
[0063] c) at least one oxygen containing organic solvent; [0064] d)
a salt of at least one somatostatin analogue comprising at least
one positively charged peptide ion and at least one negatively
charged counter-ion; wherein said at least one negatively charged
counter-ion is a halide ion, preferably a chloride or bromide
ion.
[0065] Preferably, the method of treatment is a method for the
treatment of at least one condition selected from acromegaly,
cancers (such as carcinomas and melanomas, tumours expressing at
least one somatostatin receptor, SSTR2-positive tumours,
SSTR-5-positive tumours, prostate cancers, gastro-entero-pancreatic
neuroendocrine (GEP NE) tumours and especially carcinoid tumours,
insulinomas, gastrinomas, vasoactive intestinal peptide
(VIP)-producing tumours and glucagonomas), elevated growth hormone
(GH), elevated IGF-I, varicial bleeding (especially esophageal),
chemotherapy induced gastro intestinal problems (such as diarrhea),
lymphorrhea, diabetic retinopathy, thyroid eye disease, obesity,
pancreatitis, and related conditions.
[0066] In a yet further aspect, the present invention provides the
use of; [0067] a) at least one diacyl glycerol; [0068] b) at least
one phosphatidyl choline; [0069] c) at least one oxygen containing
organic solvent; [0070] d) at a salt of at least one somatostatin
analogue comprising at least one positively charged peptide ion and
at least one negatively charged counter-ion; in the manufacture of
a low viscosity pre-formulation medicament for use in the in vivo
formation of a depot for treatment of acromegaly, cancer (such as
carcinomas and melanomas, tumours expressing at least one
somatostatin receptor, SSTR2-positive tumours, SSTR-5-positive
tumours, prostate cancers, GEP NE tumours and especially carcinoid
tumours, insulinomas, gastrinomas, VIP-producing tumours and
glucagonomas), elevated GH, elevated IGF-I, varicial bleeding
(especially espohageal), chemotherapy induced gastro intestinal
problems (such as diarrhea), lymphorrhea, diabetic retinopathy,
thyroid eye disease, obesity, pancreatitis, and/or related
conditions wherein said at least one negatively charged counter-ion
is a halide ion, preferably a chloride or bromide ion.
[0071] The pre-formulations of the present invention are highly
advantageous in that they are stable to prolonged storage in their
final "administration ready" form. As a result, they may readily be
supplied for administration either by health professionals or by
patients or their careers, who need not be fully trained health
professionals and may not have the experience or skills to make up
complex preparations. It is the surprising finding of the inventors
that compositions wherein the peptide active is in the form of a
salt with the specified counter-ions (as described herein) are
significantly more stable even than the relatively stable
compositions described in WO2006/075124 having acetate
counter-ions.
[0072] In a yet further aspect, the present invention provides a
disposable administration device (which is also to include a device
component) pre-loaded with a measured dose of a preformulation of
the present invention. Such a device will typically contain a
single dose ready for administration and will generally be
sterile-packed such that the composition is stored within the
device until administration. Suitable devices include cartridges,
ampoules and particularly syringes and syringe barrels, either with
integral needles or with standard (e.g. luer) fittings adapted to
take a suitable disposable needle.
[0073] In an additional aspect, the present invention thus provides
a disposable administration device pre-loaded with a measured dose
of a preformulation comprising a low viscosity mixture of: [0074]
a) at least one diacyl glycerol; [0075] b) at least one
phosphatidyl choline; [0076] c) at least one oxygen containing
organic solvent; [0077] d) a salt of at least one somatostatin
analogue comprising at least one positively charged peptide ion and
at least one negatively charged counter-ion; (especially wherein
the pre-formulation forms, or is capable of forming, at least one
liquid crystalline phase structure upon contact with an aqueous
fluid) wherein said at least one negatively charged counter-ion is
a halide ion, preferably a chloride or bromide ion.
[0078] The pre-filled devices of the invention may also suitably be
included in an administration kit, which kit also forms a further
aspect of the invention. In a still further aspect, the invention
thus provides a kit for the administration of at least one
somatostatin analogue, said kit containing a measured dose of a
formulation of the invention and optionally an administration
device or component thereof. Preferably the dose will be held
within the device or component, which will be suitable for i.m. or
preferably s.c. administration. The kits may include additional
administration components such as needles, swabs, etc. and will
optionally and preferably contain instructions for administration.
Such instructions will typically relate to administration by a
route as describe herein and/or for the treatment of a disease
indicated herein above.
[0079] In a yet further aspect, the invention thus additionally
provides kit for the administration of at least one somatostatin
analogue, said kit containing a measured dose of a formulation
comprising a low viscosity mixture of: [0080] a) at least one
diacyl glycerol; [0081] b) at least one phosphatidyl choline;
[0082] c) at least one oxygen containing organic solvent; and
[0083] d) a salt of at least one somatostatin analogue comprising
at least one positively charged peptide ion and at least one
negatively charged counter-ion; (especially wherein the
pre-formulation forms, or is capable of forming, at least one
liquid crystalline phase structure upon contact with an aqueous
fluid) wherein said at least one negatively charged counter-ion is
a halide ion, preferably a chloride or bromide ion.
[0084] Although the present invention is applicable to all types of
slow-release compositions (e.g. those requiring dosing no more
frequently than every 7 days), certain formulations of the present
invention generate a non-lamellar liquid crystalline phase
following administration. The use of non-lamellar phase structures
(such as liquid crystalline phases) in the delivery of bioactive
agents is now relatively well established. Such structures form
when an amphiphilic compound is exposed to a solvent because the
amphiphile has both polar and apolar groups which cluster to form
polar and apolar regions. These regions can effectively solubilise
both polar and apolar compounds. In addition, many of the
structures formed by amphiphiles in polar and/or apolar solvents
have a very considerable area of polar/apolar boundary at which
other amphiphilic compounds can be adsorbed and stabilised.
Amphiphiles can also be formulated to protect active agents, to at
least some extent, from aggressive biological environments,
including enzymes, and thereby provide advantageous control over
active agent stability and release.
[0085] The formation of non-lamellar regions in the
amphiphile/water, amphiphile/oil and amphiphile/oil/water phase
diagrams is a well known phenomenon. Such phases include liquid
crystalline phases such as the cubic P, cubic D, cubic G and
hexagonal phases, which are fluid at the molecular level but show
significant long-range order, and the L3 phase which comprises a
multiply interconnected bi-continuous network of bilayer sheets
which are non-lamellar but lack the long-range order of the liquid
crystalline phases. Depending upon their curvature of the
amphiphile sheets, these phases may be described as normal (mean
curvature towards the apolar region) or reversed (mean curvature
towards the polar region).
[0086] The non-lamellar liquid crystalline and L3 phases are
thermodynamically stable systems. That is to say, they are not
simply a meta-stable state that will separate and/or reform into
layers, lamellar phases or the like, but are the stable
thermodynamic form of the lipid/solvent mixture.
[0087] Where they form liquid crystalline depot compositions after
administration, it is important that the pre-formulations of the
invention are not liquid crystalline prior to administration
because bulk liquid crystalline phase is generally highly viscous.
These pre-formulations are thus low viscosity,
non-liquid-crystalline formulations which undergo a phase change
upon administration to form a liquid crystalline mass. Particularly
preferred examples of low viscosity mixtures are molecular
solutions and/or isotropic phases such as L2 and/or L3 phases. As
describe above, the L3 is a non-lamellar phase of interconnected
sheets which has some phase structure but lacks the long-range
order of a liquid crystalline phase. Unlike liquid crystalline
phases, which are generally highly viscous, L3 phases are of lower
viscosity. Obviously, mixtures of L3 phase and molecular solution
and/or particles of L3 phase suspended in a bulk molecular solution
of one or more components are also suitable. The L2 phase is the
so-called "reversed micellar" phase or microemulsion. Most
preferred low viscosity mixtures are molecular solutions, L3 phases
and mixtures thereof. L2 phases are less preferred, except in the
case of swollen L.sub.2 phases as described below.
[0088] As used herein, the term "low viscosity mixture" is used to
indicate a mixture which may be readily administered to a subject
and in particular readily administered by means of a standard
syringe and needle arrangement. This may be indicated, for example
by the ability to be dispensed from a 1 ml disposable syringe
through a small gauge needle. Preferably, the low viscosity
mixtures can be dispensed through a needle of 19 awg, preferably
smaller than 19 gauge, more preferably 23 awg (or most preferably
even 27 gauge) needle by manual pressure. In a particularly
preferred embodiment, the low viscosity mixture should be a mixture
capable of passing through a standard sterile filtration membrane
such as a 0.22 .mu.m syringe filter. A typical range of suitable
viscosities would be, for example, 0.1 to 5000 mPas, preferably 1
to 1000 mPas at 20.degree. C.
[0089] It has been observed that by the addition of small amounts
of low viscosity solvent, as indicated herein, a very significant
change in viscosity can be provided. As indicated in FIG. 1, for
example, the addition of only 5% solvent to a lipid mixture can
reduce viscosity 100-fold and addition of 10% may reduce the
viscosity up to 10,000 fold. In order to achieve this non-linear,
synergistic effect, in lowering viscosity it is important that a
solvent of appropriately low viscosity and suitable polarity be
employed. Such solvents include those described herein infra.
[0090] The present invention provides a pre-formulation comprising
components a, b, c and at least one peptide salt, such as a salt of
a somatostatin analogue as indicated herein. The amounts of these
components will typically be in the range 40-70% a), 30-60% b) and
0.1-20% c), with the peptide salt present at 0.1% to 10%. All %
being by weight herein throughout, unless otherwise indicated. The
formulations may consist of essentially only these components and
in one aspect consist entirely of such components. Preferable
ranges for component a) are 43-60%, particularly 45-55 and
preferable ranges of component b) are 35-55%, particularly 40 to
50%. The preferred range for component c) is 0.1 to 10%. These and
all preferable aspects of the invention may be used individually or
in any combination, unless specifically indicated otherwise.
[0091] Ratios of a:b are typically 40:60 to 70:30, preferably 45:55
to 60:40 and more preferably 48:52 to 55:45. Ratios of around 50:50
are highly effective.
[0092] The amount of solvent component c) in a preformulation will
have a considerable effect upon several features. In particular,
the viscosity and the rate (and duration) of release will alter
significantly with the solvent level. The amount of solvent will
thus be at least sufficient to provide a low viscosity mixture but
will additionally be determined so as to provide the desired
release rate. This may be determined by routine methods in view of
the Examples below. Typically a level of 0.1 to 20% solvent will
provide suitable release and viscosity properties. This will
preferably be 0.1 to 10%, more preferably 2 to 8% and an amount of
around 5% is highly effective.
[0093] It is the remarkable finding of the present inventors that
the proportion of solvent in the formulation can be used to "tune"
the release profile of the active agent during the first few days
of release. In particular, although all formulations of the
invention have a surprisingly low "burst/lag" effect (in fact there
may be no lag period at all), and reach a plateau release level
within a few days (e.g. 5 days, preferably 3 days, more preferably
1 day) of injection, if a controlled "burst"/initial release of
active agent is required in the first 1-2 days then this can be
provided by increasing the solvent proportion to the upper region
of the range given above. In contrast, in the mid- to lower-region
of the range, a formulation giving a depot with essentially no
burst and a rapid decline to the plateau release level is
provided.
[0094] Thus, in one embodiment, the present invention provides
formulations and depots containing around 0.1 to 6 wt % component
c) and having a low release of the active compound during the first
days after administration ("low-burst profile"). In an alternative
embodiment, the present invention provides formulations and depots
containing around 6.5 to 10 wt % component c) and having high
initial release of the active compound during the first days after
administration ("burst profile").
[0095] The low initial release ("low-burst profile") of active
agent is defined such that the area under a plasma concentration
against time the curve during the first 24 hours is less than 15%
of the area under the curve for the entire curve (measured or
extrapolated from time 0 to infinity or from time 0 to the last
sampling time point), more preferably less than 10% and most
preferable less than 7%. In addition, the decline to plateau plasma
concentration levels after the initial peak should be rapid, such
that plateau is reached with in 48 hours, more preferably within 24
hours, and most preferably within 12 hours. Conversely, a high
initial release ("burst profile") is such that more than 15% of
active agent is released within 24 hours and more preferably more
than 20% is released during the first 24 hours. The decline to
plateau will not occur until after 36 hours, more preferably after
48 hours and most preferably after 72 hours. It is preferable that
each of these profiles is combined with a rapid settling of the
plasma active agent concentration to "plateau" level. For example,
the plasma concentration after 10 days should be no more than 50%
greater or less than the average concentration over days 5 to 20.
Preferably this will be no more than 30% and more preferably no
more than 20%.
[0096] As indicated above, the amount of component c) in the
pre-formulations of the invention will be at least sufficient to
provide a low viscosity mixture (e.g. a molecular solution, see
above) of components a, b and c and will be easily determined for
any particular combination of components by standard methods. The
phase behaviour itself may be analysed by techniques such as visual
observation in combination with polarized light microscopy, nuclear
magnetic resonance, and cryo-transmission electron microscopy
(cryo-TEM) to look for solutions, L2 or L3 phases, or liquid
crystalline phases. Viscosity may be measured directly by standard
means. As described above, an appropriate practical viscosity is
that which can effectively be syringed and particularly sterile
filtered. This will be assessed easily as indicated herein.
[0097] Component "a" as indicated herein is at least one diacyl
glycerol (DAG) and thus has two non-polar "tail" groups. The two
non-polar groups may have the same or a differing number of carbon
atoms and may each independently be saturated or unsaturated.
Examples of non-polar groups include C6-C32 alkyl and alkenyl
groups, which are typically present as the esters of long chain
carboxylic acids. These are often described by reference to the
number of carbon atoms and the number of unsaturations in the
carbon chain. Thus, CX:Z indicates a hydrocarbon chain having X
carbon atoms and Z unsaturations. Examples particularly include
caproyl (C6:0), capryloyl (C8:0), capryl (C10:0), lauroyl (C12:0),
myristoyl (C14:0), palmitoyl (C16:0), phytanoyl (C16:0),
palmitoleoyl (C16:1), stearoyl (C18:0), oleoyl (C18:1), elaidoyl
(C18:1), linoleoyl (C18:2), linolenoyl (C18:3), arachidonoyl
(C20:4), behenoyl (C22:0) and lignoceroyl (C24:9) groups. Thus,
typical non-polar chains are based on the fatty acids of natural
ester lipids, including caproic, caprylic, capric, lauric,
myristic, palmitic, phytanic, palmitolic, stearic, oleic, elaidic,
linoleic, linolenic, arachidonic, behenic or lignoceric acids, or
the corresponding alcohols.
[0098] Preferable non-polar chains are palmitic, stearic, oleic and
linoleic acids, particularly oleic acid.
[0099] Mixtures of any number of diacyl lipids may be used as
component a. Preferably this component will include at least a
portion of glycerol dioleate (GDO). A highly preferred example is
DAG comprising at least 50%, preferably at least 80% and even
comprising substantially 100% GDO.
[0100] Since GDO and other diacyl glycerols are products derived
from natural sources, there is generally a certain proportion of
"contaminant" lipid having other chain lengths etc. In one aspect,
GDO as used herein is thus used to indicate any commercial grade of
GDO with concomitant impurities (i.e. GDO of commercial purity).
These impurities may be separated and removed by purification but
providing the grade is consistent this is rarely necessary. If
necessary, however, "GDO" may be essentially chemically pure GDO,
such as at least 80% pure, preferably at least 85% pure and more
preferably at least 90% pure GDO.
[0101] Component "b" in the present invention is at least one
phosphatidyl choline (PC). As with component a, this component
comprises a polar head group and at least one non-polar tail group.
The difference between components a and b lies principally in the
polar group. The non-polar portions may thus suitably be derived
from the fatty acids or corresponding alcohols considered above for
component a. As with component a), the PC will contain two
non-polar groups.
[0102] The phosphatidyl choline portion, even more suitably than
any diacyl glycerol portion, may be derived from a natural source.
Suitable sources of phospholipids include egg, heart, brain, liver
(e.g. bovine) and plant sources including soybean. Such sources may
provide one or more constituents of component b, which may comprise
any mixture of phospholipids. Any single PC or mixture of PCs from
these or other sources may be used, but mixtures comprising soy PC
are highly suitable. The PC component preferably contains at least
50% soy PC, more preferably at least 75% soy PC and most preferably
essentially pure soy PC.
[0103] Since the pre-formulations of the invention are to be
administered to a subject for the controlled release of a
somatostatin analogue active agent, it is important that the
components are biocompatible. In this regard, the preformulations
of the present invention are highly advantageous since both PC and
DAGs are well tolerated and are broken down in vivo into components
that are naturally present in the mammalian body.
[0104] A particularly favoured combination of components a and b
are GDO with PC, especially GDO with soy PC.
[0105] Component "c" of the pre-formulations of the invention is an
oxygen containing organic solvent. Since the pre-formulation is to
generate a depot composition following administration (e.g. in
vivo), upon contact with an aqueous fluid, it is desirable that
this solvent be tolerable to the subject and be capable of mixing
with the aqueous fluid, and/or diffusing or dissolving out of the
pre-formulation into the aqueous fluid. Solvents having at least
moderate water solubility are thus preferred.
[0106] In a preferred version, the solvent is such that a
relatively small addition to the composition comprising a and b,
i.e. preferably below 10%, give a large viscosity reductions of one
order of magnitude or more. As described herein, the addition of
10% solvent can give a reduction of two, three or even four orders
of magnitude in viscosity over the solvent-free composition, even
if that composition is a solution or L.sub.2 phase containing no
solvent, or an unsuitable solvent such as water, or glycerol.
[0107] Typical solvents suitable for use as component c include at
least one solvent selected from alcohols, ketones, esters
(including lactones), ethers, amides and sulphoxides. Alcohols are
particularly suitable and form the preferred class of solvents.
Examples of suitable alcohols include ethanol, isopropanol and
glycerol formal. Ethanol is most preferred. Monools are preferred
to diols and polyols. Where diols or polyols are used, this is
preferably in combination with an at least equal amount of monool
or other preferred solvent. Examples of ketones include acetone and
propylene carbonate. Suitable ethers include diethylether,
glycofurol, diethylene glycol monoethyl ether, dimethylisobarbide,
and polyethylene glycols. Suitable esters include ethyl acetate,
benzyl benzoate and isopropyl acetate and dimethyl sulphide is as
suitable sulphide solvent. Suitable amides and sulphoxides include
n-methyl pyrrolidone (NMP), 2-pyrrolidone, dimethylacetamide (DMA)
and dimethylsulphoxide (DMSO), respectively.
[0108] A highly preferred combination is soy PC, GDO and ethanol.
This is especially compatible with the chloride or bromide of a
somatostatin analogue, such as octreotide chloride. Compositions
around 40-60% PC, 40-60% GDO, 3-10% Ethanol and 1 to 8% Octreotide
chloride are preferred examples.
[0109] It is preferable that little or none of component c contains
halogen substituted hydrocarbons since these tend to have lower
biocompatibility. Where a portion of halogenated solvent such as
dichloromethane or chloroform is necessary, this proportion will
generally be minimised.
[0110] Component c as used herein may be a single solvent or a
mixture of suitable solvents but will generally be of low
viscosity. This is important because one of the key aspects of the
present invention is that it provides preformulations that are of
low viscosity and a primary role of a suitable solvent is to reduce
this viscosity. This reduction will be a combination of the effect
of the lower viscosity of the solvent and the effect of the
molecular interactions between solvent and lipid composition. One
observation of the present inventors is that the oxygen-containing
solvents of low viscosity described herein have highly advantageous
and unexpected molecular interactions with the lipid parts of the
composition, thereby providing a non-linear reduction in viscosity
with the addition of a small volume of solvent.
[0111] The viscosity of the "low viscosity" solvent component c
(single solvent or mixture) should typically be no more than 18
mPas at 20.degree. C. This is preferably no more than 15 mPas, more
preferably no more than 10 mPas and most preferably no more than 7
mPas at 20.degree. C.
[0112] A further advantage of the present pre-formulations is that
a higher level of bioactive agent may be incorporated into the
system. In particular, by appropriate choice of components a-c
(especially c), high levels of active agent may be dissolved or
suspended in the pre-formulations. This allows a reduction in the
administered volume and thus less discomfort to subjects.
[0113] The pre-formulations of the present invention typically do
not contain significant amounts of water. Since it is essentially
impossible to remove every trace of water from a lipid composition,
this is to be taken as indicating that only such minimal trace of
water exists as cannot readily be removed. Such an amount will
generally be less than 1% by weight, preferably less that 0.5% by
the weight of the pre-formulation. In one preferred aspect, the
pre-formulations of the invention do not contain glycerol, ethylene
glycol or propylene glycol and contain no more than a trace of
water, as just described.
[0114] Certain of the pre-formulations of the present invention
contain salts of one or more somatostatin analogues (which are
preferred examples of the peptide actives, which in turn are
intended by any reference to "active agents" herein). Since SST-14
is a peptide hormone, typical somatostatin analogues will be
peptides, especially of 14 or fewer amino acids. Preferably such
peptides will be structurally constrained such as by being cyclic
and/or having at least one intra-molecular cross-link. Amide, ester
or particularly disulphide crosslinks are highly suitable.
Preferred constrained peptides will exhibit a type-2 .beta. turn.
Such a turn is present in the key region of somatostatin. Peptides
may contain only amino acids selected from those 20 .alpha.-amino
acids indicated in the genetic code, or more preferably may contain
their isomers and other natural and non-natural amino acids,
(generally .alpha., .beta. or .gamma., L- or D-amino acids) and
their analogues and derivatives. The term "somatostatin analogue"
as used herein may optionally also encompass SST-14 and/or SST-28,
since these are viable peptide actives when formulated as salts in
the very high performance slow-release formulations described
herein.
[0115] Amino acid derivatives and amino acids not normally used for
protein synthesis are especially useful at the termini of the
peptides, where the terminal amino or carboxylate group may be
substituted by or with any other functional group such as hydroxy,
alkoxy, ester, amide, thio, amino, alkyl amino, di- or tri-alkyl
amino, alkyl (by which is meant, herein throughout C.sub.1-C.sub.12
alkyl, preferably C.sub.1-C.sub.6 alkyl e.g. methyl, ethyl,
n-propyl, isopropyl, n-butyl, iso-, sec- or t-butyl etc.), aryl
(e.g phenyl, benzyl, napthyl etc) or other functional groups,
preferably with at least one heteroatom and preferably having no
more than 10 atoms in total, more preferably no more than 6.
[0116] Particularly preferred somatostatin analogues are
constrained peptides of 6 to 10 .alpha.-amino acids, of which
particular examples include octreotide, lanreotide (of sequence
NH.sub.2-(D)Naph-Cys-Tyr-(D)Trp-Lys-Val-Cys-Thr-CONH.sub.2 and its
cyclic derivative of sequence
NH.sub.2-(D)Naph-Cys-Tyr-(D)Phe-Lys-Val-Cys-Thr-CONH.sub.2 both
having a Cys-Cys intramolecular disulphide crosslink), SOM 230 (see
structure below) and vapreotide. Most preferred is octreotide.
##STR00001##
[0117] The somatostatin analogue will generally be formulated as
0.1 to 10% by weight of the total formulation. Typical values will
be 1 to 9%, preferably 2 to 9% and more preferably 2.5 to 8%. A
somatostatin analogue content of around 6% is most preferable.
[0118] Doses of the somatostatin analogue suitable for inclusion in
the formulation, and thus the volume of formulation used will
depend upon the release rate (as controlled, for example by the
solvent type and amount use) and release duration, as well as the
desired therapeutic level, the activity and the rate of clearance
of the particular active chosen. Typically an amount of 1 to 500 mg
per dose would be suitable for providing a therapeutic level for
between 7 and 90 days. This will preferably be 5 to 300 mg. For
octreotide, the level will typically be around 10 to 180 mg (e.g.
for a 30 to 90 day duration). Preferably, the amount of octreotide
will be around 0.2 to 3 mg per day between injections. Thus a depot
administered every 30 days would have 6 to 90 mg or a 90 day depot
have 18 to 270 mg of octreotide.
[0119] One of the surprising advantages of the specific peptide
salts indicated herein is that they allow for an extremely gradual
release of active agent and thus a depot composition containing a
large amount of active for release over a long period. Release
durations of, for example, up to 180 days are thus within the reach
of the compositions of the invention and doses of up to 1 g of
active agent may be necessary for such long-acting depots.
[0120] For ease of reference, terms such as "peptide",
"somatostatin analogue", "octreotide" and other peptides are used
and referred to herein. In the present invention, this reference is
to the halide (e.g. chloride or bromide or mixture thereof) salt
where context allows rather than to the free peptide, or is to the
peptide cation, where one or more anionic counter-ions is
indicated.
[0121] The pre-formulations of the present invention are formulated
to be administered parenterally. This administration will generally
not be an intra-vascular method but will preferably be subcutaneous
intracavitary or intramuscular. Typically the administration will
be by injection, which term is used herein to indicate any method
in which the formulation is passed through the skin, such as by
needle, catheter or needle-less injector.
[0122] Preferred parenteral administration will depend upon the
particular slow-release formulation used in the invention. For the
preferred lipid depot systems, for example, it is preferable to
administer the preformulation by i.m or s.c. injection, most
preferably by deep s.c. injection. This has the advantage of being
less deep and less painful to the subject than the (deep) i.m.
injection used for administration of polymer-type octreotide depots
and is technically most suitable in the present case as it combines
ease of injection with low risk of skin side effects. Evidently,
for polymer-type depot compositions, i.m. injection is
preferred.
[0123] The pre-formulations of the present invention provide
non-lamellar liquid crystalline depot compositions upon exposure to
aqueous fluids, especially in vivo. As used herein, the term
"non-lamellar" is used to indicate a normal or reversed liquid
crystalline phase (such as a cubic or hexagonal phase) or the L3
phase or any combination thereof. The term liquid crystalline
indicates all hexagonal, all cubic liquid crystalline phases and/or
all mixtures thereof. Hexagonal as used herein indicates "normal"
or "reversed" hexagonal (preferably reversed) and "cubic" indicates
any cubic liquid crystalline phase unless specified otherwise.
[0124] For many combinations of lipids, only certain non-lamellar
phases exist, or exist in any stable state. It is a surprising
feature of the present invention that compositions as described
herein frequently exhibit non-lamellar phases which are not present
with many other combinations of components. In one particularly
advantageous embodiment, therefore, the present invention relates
to compositions having a combination of components for which an
I.sub.2 and/or L.sub.2 phase region exists when diluted with
aqueous solvent. The presence or absence of such regions can be
tested easily for any particular combination by simple dilution of
the composition with aqueous solvent and study of the resulting
phase structures by the methods described herein.
[0125] In a highly advantageous embodiment, the compositions of the
invention may form an I.sub.2 phase, or a mixed phase including
I.sub.2 phase upon contact with water. The I.sub.2 phase is a
reversed cubic liquid crystalline phase having discontinuous
aqueous regions. This phase is of particular advantage in the
controlled release of active agents and especially in combination
with polar active agents, such as water soluble actives because the
discontinuous polar domains prevent rapid diffusion of the actives.
Depot precursors in the L.sub.2 are highly effective in combination
with an I.sub.2 phase depot formation. This is because the L.sub.2
phase is a so-called "reversed micellar" phase having a continuous
hydrophobic region surrounding discrete polar cores. L.sub.2 thus
has similar advantages with hydrophilic actives.
[0126] In transient stages after contact with body fluid the
composition can comprise multiple phases since the formation of an
initial surface phase will retard the passage of solvent into the
core of the depot, especially with substantial sized
administrations of internal depots. Without being bound by theory,
it is believed that this transient formation of a surface phase,
especially a liquid crystalline surface phase, serves to
dramatically reduce the "burst/lag" profile of the present
compositions by immediately restricting the rate of exchange
between the composition and the surroundings. Transient phases may
include (generally in order from the outside towards the centre of
the depot): H.sub.II or L.sub..alpha., I.sub.2, L.sub.2, and liquid
(solution). It is highly preferred that the composition of the
invention is capable forming at least two and more preferably at
least three of these phases simultaneously at transient stages
after contact with water at physiological temperatures. In
particular, it is highly preferred that one of the phases formed,
at least transiently, is the I.sub.2 phase.
[0127] It is important to appreciate that the preformulations of
the present invention are of low viscosity. As a result, these
preformulations must not be in any bulk liquid crystalline phase
since all liquid crystalline phases have a viscosity significantly
higher than could be administered by syringe or spray dispenser.
The preformulations of the present invention will thus be in a
non-liquid crystalline state, such as a solution, L.sub.2 or
L.sub.3 phase, particularly solution or L.sub.2. The L.sub.2 phase
as used herein throughout is preferably a "swollen" L.sub.2 phase
containing greater than 10 wt % of solvent (component c) having a
viscosity reducing effect. This is in contrast to a "concentrated"
or "non-swollen" L.sub.2 phase containing no solvent, or a lesser
amount of solvent, or containing a solvent (or mixture) which does
not provide the decrease in viscosity associated with the
oxygen-containing, low viscosity solvents specified herein.
[0128] Upon administration, the pre-formulations of the present
invention undergo a phase structure transition from a low viscosity
mixture to a high viscosity (generally tissue adherent) depot
composition. Generally this will be a transition from a molecular
mixture, swollen L.sub.2 and/or L3 phase to one or more (high
viscosity) liquid crystalline phases such as normal or reversed
hexagonal or cubic liquid crystalline phases or mixtures thereof.
As indicated above, further phase transitions may also take place
following administration. Obviously, complete phase transition is
not necessary for the functioning of the invention but at least a
surface layer of the administered mixture will form a liquid
crystalline structure. Generally this transition will be rapid for
at least the surface region of the administered formulation (that
part in direct contact with air, body surfaces and/or body fluids).
This will most preferably be over a few seconds or minutes (e.g. up
to 30 minutes, preferably up to 10 minutes, more preferably 5
minutes of less). The remainder of the composition may change phase
to a liquid crystalline phase more slowly by diffusion and/or as
the surface region disperses.
[0129] In one preferred embodiment, the present invention thus
provides a pre-formulation as described herein of which at least a
portion forms a hexagonal liquid crystalline phase upon contact
with an aqueous fluid. The thus-formed hexagonal phase may
gradually disperse and/or degrade, releasing the active agent, or
may subsequently convert to a cubic liquid crystalline phase, which
in turn then gradually disperses. It is believed that the hexagonal
phase will provide a more rapid release of active agent, in
particular of hydrophilic active agent, than the cubic phase
structure, especially the I.sub.2 and L.sub.2 phase. Thus, where
the hexagonal phase forms prior to the cubic phase, this will
result in an initial release of active agent to bring the
concentration up to an effective level rapidly, followed by the
gradual release of a "maintenance dose" as the cubic phase
degrades. In this way, the release profile may be controlled.
[0130] Without being bound by theory, it is believed that upon
exposure (e.g. to body fluids), the pre-formulations of the
invention lose some or all of the organic solvent included therein
(e.g. by diffusion) and take in aqueous fluid from the bodily
environment (e.g. the in vivo environment) such that at least a
part of the formulation generates a non-lamellar, particularly
liquid crystalline phase structure. In most cases these
non-lamellar structures are highly viscous and are not easily
dissolved or dispersed into the in vivo environment. The result is
a monolithic "depot" generate in vivo with only a limited area of
exposure to body fluids. Furthermore, because the non-lamellar
structure has large polar, apolar and boundary regions, it is
highly effective in solubilising and stabilising active agents such
as peptides and protecting these from degradation mechanisms. As
the depot composition formed from the pre-formulation gradually
degrades over a period of days, weeks or months, the active agent
is gradually released and/or diffuses out from the composition.
Since the environment within the depot composition is relatively
protected, the pre-formulations of the invention are highly
suitable for active agents with a relatively low biological
half-life (see above).
[0131] The depot systems formed by the formulations of the present
invention are highly effective in protecting the active agent from
degradation and thus allow an extended release period. Comparative
tests have been carried out between the known PLGA slow-release
product and formulations of the present invention containing GDO,
soy PC, ethanol and octreotide. These indicate that formulations of
the present invention give lesser degradation under simulated in
vivo conditions than known compositions of octreotide with PLGA
microspheres. The formulations of the invention thus may provide in
vivo depots of somatostatin analogues which require administration
only once every 20 to 90 days, preferably 30 to 60 days, more
preferably 35 to 48 days. Evidently, a longer stable release period
is desirable for patient comfort and compliance as well as
demanding less time from health professionals.
[0132] A considerable advantage of the lipid-based depot precursors
preferred in the present invention is that they are stable
homogeneous phases. That is to say, they may be stored for
considerable periods (preferably at least 6 months) without phase
separation. As well as providing advantageous storage, this allows
for the dose of somatostatin analogue to be selected by reference
to the species, age, sex, weight, and/or physical condition of the
individual subject, by means of injecting a selected volume.
Furthermore, the present inventors have surprisingly found that the
dose of active agent is proportional to the volume of composition
injected, in ranges of at least 10-fold in sample volume injection
(see examples and figures below). This is highly unexpected because
a 10-fold increase in depot weight will not provide a corresponding
increase in surface area (the area of an object increasing to the
two-third power of the increase in volume) and so release would be
expected to be less than 10-times enhanced. Even in situations
where dosing is not directly proportional to injection volume,
however, the homogeneous nature of the depot precursors allow for
partial administration of a pre-measured dose and this
administration may be made by reference to a dosing table, chart,
software calculation etc. which may take into account any or all
relevant subject variables.
[0133] In the lipid-depot embodiment, the present invention thus
provides for methods comprising the selection of a dosing amount
specific to an individual, particularly by subject weight. The
means for this dose selection being by administration volume.
[0134] It is an unexpected finding of the present inventors that
the pre-formulations result in a depot composition that have very
little "burst" effect in the active agent release profile. This is
unexpected because it might be expected that the low viscosity
mixture (especially if this is a solution) of the pre-composition
would rapidly lose active agent upon exposure to water. In fact,
pre-formulations of the invention have shown considerably less of
an initial "burst" than previously known polymer-base depot
compositions which tend to have an initial "wash off" of
surface-bound active agent. This is illustrated in the Examples
below and Figures attached hereto. In one embodiment, the invention
thus provides injectible preformulations and resulting depot
compositions wherein the highest plasma concentration of active
after administration is no more than 10 times the average
concentration between 24 hours and 5 days of administration. This
ratio is preferably no more than 8 times and most preferably no
more than 5 times the average concentration.
[0135] The compositions of the invention (especially those using
the preferred lipid depot systems) also allow for the generation of
depot compositions with very little "lag" effect after
administration. In a further embodiment, the invention thus
provides injectible preformulations and resulting depot
compositions wherein the plasma concentration of active at 7 days
after a single administration is no lower than the plasma
concentration of active at 21 days after administration. Similarly,
the concentration of active should be higher at all times in the
first 21 days than the concentration at any time from 30 days after
administration onwards. This gradually decaying release profile has
not previously been demonstrated for a somatostatin analogue
formulation.
[0136] The compositions of the present invention wherein the
peptide active agent is in the form of a halide salt (e.g. chloride
or bromide) show surprisingly advantageous release profiles in
comparison with the same formulations using the more common salts
such as acetate. The release rate may be up to around 4 times
slower for the chloride salt than the acetate (e.g. for octreotide)
and thus a depot composition may potentially be provided with up to
four times the effective duration. This is obviously of
considerable benefit and is highly unexpected when it is considered
that only the counter-ion is changed and the actual functional
peptide ion remains identical. No consideration is thought to have
ever previously been given to the potential advantages of such
salts in slow-release compositions.
[0137] Without being bound by theory, it is believed that the
counter-ion permeability in the matrix of the slow-release
composition may be responsible for this difference. This would
suggest that the chloride ion, for example, permeates the depot
compositions more slowly than the acetate ion.
[0138] The following features are preferred, both individually and
in combination, in the various aspects of the invention:
[0139] The sustained-release delivery vehicle is a biodegradable
polymer (such as polylactate, polyglycolate or PLGA) or a
lipid-based slow release formulation including those described
herein.
[0140] The peptide active agent is at least one somatostatin
analogue salt selected from the halides of those indicated herein,
preferably of octreotide, lanreotide, SOM230, or vapreotide;
[0141] Component a comprises, consists essentially of or preferably
consists of GDO;
[0142] Component b comprises, consists essentially of or preferably
consists of soy PC;
[0143] Component c comprises, consists essentially of or preferably
consists of a 1, 2, 3 or 4 carbon alcohol, preferably isopropanol
or more preferably ethanol;
[0144] The preformulation has a low viscosity as indicated
herein.
[0145] The preformulation forms a liquid crystalline phase as
indicated herein upon in vivo administration.
[0146] The preformulation generates a depot following in vivo
administration, which depot releases at least one somatostatin
analogue at a therapeutic level over a period of at least 30 days,
preferably at least 40 days, more preferably at least 60 days.
[0147] In combination with the features and preferred features
indicated herein, the method(s) of treatment of the present
invention may have one or more of the following preferred features
independently or in combination:
[0148] The method comprises the administration of at least one
formulation with one or more preferred features as indicated
above;
[0149] The method comprises the administration of at least one
formulation as indicated herein by i.m., s.c. or preferably deep
s.c. injection;
[0150] The method comprises administration by means of a pre-filled
administration device as indicated herein;
[0151] The method comprises administration through a needle no
larger than 19 gauge, preferably smaller than 19 gauge, more
preferably 23 gauge;
[0152] The method comprises a single administration every 20 to 180
days, preferably 30 to 60 days, more preferably 35 to 48 days.
[0153] In combination with the features and preferred features
indicated herein, the use(s) of the preformulations indicated
herein in the manufacture of medicaments may have one or more of
the following preferred features independently or in
combination:
[0154] The use comprises the use of at least one formulation with
one or more preferred features as indicated above;
[0155] The use comprises the manufacture of a medicament for
administration of at least one formulation as indicated herein by
i.m., s.c. or preferably deep s.c. injection;
[0156] The use comprises the manufacture of a medicament for
administration by means of a pre-filled administration device as
indicated herein;
[0157] The use comprises the manufacture of a medicament for
administration through a needle no larger than 19 gauge, preferably
smaller than 19 gauge, more preferably 23 gauge or smaller;
[0158] The use comprises the manufacture of a medicament for
administration once every 20 to 180 days, preferably 30 to 60 days,
more preferably 35 to 48 days.
[0159] In combination with the features and preferred features
indicated herein, the pre filled devices of the invention may have
one or more of the following preferred features independently or in
combination:
[0160] They contain a preferred formulation as indicated herein;
They comprise a needle smaller than 19 gauge, preferably no larger
than 23 gauge; They contain a single dose of 1 to 1000 mg of
somatostatin analogue salt, preferably 5 to 300 mg;
[0161] They contain octreotide chloride, at around 10 to 180
mg;
[0162] They contain octreotide chloride at around 0.2 to 3 mg per
day between scheduled administrations;
[0163] They contain a total volume for administration of no more
than 5 ml, preferably no more than 3 ml more preferably no more
than 2 ml.
[0164] In combination with the features and preferred features
indicated herein, the kits of the invention may have one or more of
the following preferred features independently or in
combination:
[0165] They contain a preferred formulation as indicated
herein;
[0166] They contain a prefilled device as indicated herein;
[0167] They contain a needle no larger than 19 gauge, preferably no
larger than 23 gauge;
[0168] They contain a single dose of 1 to 1000 mg of somatostatin
analogue salt, preferably 5 to 300 mg;
[0169] They contain octreotide chloride, at around 10 to 180
mg;
[0170] They contain octreotide chloride at around 0.2 to 3 mg per
day between scheduled administrations;
[0171] They contain a total volume for administration of no more
than 5 ml, preferably no more than 3 ml more preferably no more
than 2 ml.
[0172] They contain instructions for administration by a route
and/or at a frequency as indicated herein;
[0173] They contain instructions for administration for use in a
method of treatment as described herein.
[0174] The invention will now be further illustrated by reference
to the following non-limiting Examples and the attached Figures, in
which;
[0175] FIG. 1 compares decreases in viscosity at 25.degree. C. of
the depot precursor on addition of solvents, including the addition
of: EtOH to PC/GDO (50/50), represented by solid circles; PG to
PC/GDO (50/50), represented by solid squares; N-methyl pyrolidinone
(NMP) to PC/GDO (50/50), represented by solid diamonds; EtOH to
PC/GDO (40/60), represented by open circles; PG to PC/GDO (40/60),
represented by open squares; and NMP to PC/GDO (40/60), represented
by open diamonds, and demonstrates the non-linear decrease of
pre-formulation viscosity upon addition of NMP and EtOH. PC/GDO
(50/50) is a precursor to a reversed hexagonal H.sub.II phase and
PC/GDO (40/60) is a precursor to a reversed cubic I.sub.2
phase.
[0176] FIG. 2 shows in vitro release of octreotide (octreotide base
(OCT(0)) over a 24 hour period at 37.degree. C. at different
formulation-to-PBS weight ratios from a formulation containing
octreotide acetate (OCT(Ac)), represented by open squares, and from
a formulation containing octreotide chloride (OCT(Cl)), represented
by closed circles. Error bars represent standard deviation
(n>2).
[0177] FIG. 3 shows the octreotide content (expressed as % of
nominal content) as a function of storage time and temperature
conditions for acetate and chloride formulations #174 and #192,
respectively. FIG. 3 shows that changing the counter-ion from
acetate (formulation #174) to chloride (formulation #192) results
in a dramatic stability enhancing effect.
[0178] FIG. 4 shows the breakdown products detected by HPLC and
expressed as % area at 215 nm for formulations containing
octreotide acetate (formulation #174) and octreotide chloride
(formulation #192). FIG. 4 shows that changing the counter-ion from
acetate (formulation #174) to chloride (formulation #192) results
in a dramatic stability enhancing effect.
EXAMPLES
Example 1
Availability of Various Liquid Crystalline Phases in the Depot by
Choice of Composition
[0179] Injectible formulations containing different proportions of
phosphatidyl choline ("PC"--Epikuron 200) and glycerol dioleate
(GDO) and with EtOH as solvent were prepared to illustrate that
various liquid crystalline phases can be accessed after
equilibrating the depot precursor formulation with excess
water.
[0180] Appropriate amounts of PC and EtOH were weighed in glass
vials and the mixture was placed on a shaker until the PC
completely dissolved to form a clear liquid solution. GDO was then
added to form an injectible homogenous solution.
[0181] Each formulation was injected in a vial and equilibrated
with excess water. The phase behaviour was evaluated visually and
between crossed polarizes at 25.degree. C. Results are presented in
Table 1.
TABLE-US-00001 TABLE 1 Formulation PC (wt %) GDO (wt %) EtOH (wt %)
Phase in H.sub.2O A 22.5 67.5 10.0 L.sub.2 B 28.8 61.2 10.0 I.sub.2
C 45.0 45.0 10.0 H.sub.II D 63.0 27.0 10.0 H.sub.II/L.sub..alpha.
L.sub.2 = reversed micellar phase I.sub.2 = reversed cubic liquid
crystalline phase H.sub.II = reversed hexagonal liquid crystalline
phase L.sub..alpha. = lamellar phase
Example 2
Viscosity in PC/GDO (5:5) or PC/GDO (4:6) on Addition of Solvent
(EtOH, PG and NMP)
[0182] A mixture of PC/GDO/EtOH with approximately 25% EtOH was
manufactured according to the method in Example 1. All, or nearly
all, of the EtOH was removed from the mixture with a rotary
evaporator (vacuum, 40.degree. C. for 1 h followed by 50.degree. C.
for 2 h) and the resulting mixture was weighed in a glass vial
after which 1, 3, 5, 10 or 20% of a solvent (EtOH, propylene glycol
(PG) or n-methyl pyrrolidone (NMP)) was added. The samples were
allowed to equilibrate several days before the viscosity was
measured with a CarriMed CSL 100 rheometer equipped with automatic
gap setting.
[0183] This example clearly illustrates the need for solvent with
certain depot precursors in order to obtain an injectable
formulation (see FIG. 1). The viscosity of solvent-free PC/GDO
mixtures increases with increasing ratio of PC. Systems with low
PC/GDO ratio (more GDO) are injectable with a lower concentration
of solvent.
Example 3
Preparation of Depot Composition Containing the Peptide
Octreotide
[0184] Octreotide acetate (24 mg or 60 mg) was dissolved in 0.1 g
EtOH. 0.36 g PC and 0.54 g GDO were subsequently dissolved in this
solution and a depot formulation precursor was obtained. Injecting
the formulation precursor into excess aqueous phase (syringe 23G;
0.6 mm.times.30 mm) resulted in a monolithic liquid crystalline
phase (I.sub.2 structure). I.e. octreotide (2.4% or 6.0%) did not
change monolith formation and phase behaviour after exposure to an
aqueous environment.
[0185] The octreotide depot precursor formulations in this Example
were tested for stability against crystallization during storage.
Each formulation was stable at 4-8.degree. C. for at least two
weeks.
Example 4
Preparation of Octreotide Chloride Salt
[0186] Octreotide chloride (OCT(Cl)) was prepared from Octreotide
acetate (OCT(Ac)) by running an aqueous solution of OCT(Ac) through
an ion-exchange column, pre-packed with the anion-exchange resin
Dowex 1.times.2 (Fluka) and pre-equilibrated with water for
injection (WFI). The adequate fractions of OCT(Cl) in WFI were
identified by measuring the conductivity of the collected
fractions. These fractions were pooled and the sample was
lyophilized by freeze-drying overnight giving the OCT(Cl) as a
white powder.
Example 5
Octreotide Acetate and Octreotide Chloride Compositions
[0187] Liquid crystalline formulations of OCT(Ac) and OCT(Cl) were
prepared in the following way: Soy phosphatidylcholine (SPC--Lipoid
S100 from Lipoid, Germany), glycerol dioleate (GDO--from Danisco,
Denmark), ethanol (EtOH 99.5%) and OCT(Ac) (PolyPeptide Labs, CA,
USA) or OCT(Cl) (as prepared in Example 4) were mixed in excess
EtOH until a homogenous liquid mixture was obtained. The EtOH
content was thereafter adjusted to 5 wt % by rotary evaporation of
the excess solvent. The sample compositions are given in the Table
below:
[0188] Formulation compositions in wt %.
TABLE-US-00002 Formulation# OCT(Ac) OCT(Cl) SPC GDO EtOH 186 3 --
46 46 5 183 -- 3 46 46 5
[0189] The in vitro release was determined by first placing a
sample of the respective formulation (0.1-0.4 g) in a well of a
96-deep-well plate. After allowing the liquid octreotide
formulation to settle in the bottom of the well for a few minutes,
phosphate buffered saline (PBS) was added in different amounts
(0.2-1 mL) to achieve the required conditions with respect to the
formulation-to-aqueous medium weight ratio (from formulation in
excess to PBS in excess). The 96-well plate was thereafter put on a
shaking table held at 37.degree. C. and with low rotating speed
(150 rpm). After 24 hours, PBS samples from the respective wells
were withdrawn and the octreotide content (in terms of octreotide
base=OCT(0)) in the aqueous release medium was analyzed by HPLC. At
least two replicates (wells) for each formulation-to-PBS ratio and
for each formulation were analyzed.
[0190] The results are shown in FIG. 2 as % octreotide (octreotide
base=OCT(0)) released from the respective formulation as a function
of formulation-to-PBS weight ratio. It is clear from FIG. 2 that
under all the investigated conditions in terms of
formulation-to-PBS weight ratios, the release of octreotide from
the formulation containing OCT(Ac) is markedly higher than for the
corresponding OCT(Cl) formulations. This fact is highly surprising
considering that only the peptide counter-ion (acetate versus
chloride) differs between the formulations. The effects observed
are essentially independent of the PBS to formulation ratio and are
of particular interest for a long-acting release depot product of
octreotide (e.g. 1 month or longer duration) where a slow release
of the peptide active agent is a pre-requisite.
Example 6
Stability of Octreotide in LC Depot Formulation--Comparison Between
Octreotide Acetate (OCT(Ac)) and Octreotide Chloride (OCT(Cl))
[0191] Experimental Details
[0192] LC formulations of OCT(Ac) and OCT(Cl) were prepared as
described above in Example 5. (OCT(Cl) was prepared from OCT(Ac) by
ion-exchange column chromatography--see Example 4). The
compositions of the formulations are given in the Table below. The
formulations were stored in glass vials with Teflon.RTM.-coated
rubber stoppers in a climate chamber (Termak) at 40.degree. C./75%
relative humidity. The octreotide content (expressed as % of
nominal content), ID and related substances were determined by HPLC
with UV detection at 215 nm.
[0193] Nominal formulation compositions in wt %.
TABLE-US-00003 OCT(Ac) OCT(Cl) Formulation# [OCT(0)] [OCT(0)] SPC
GDO EtOH 174 4.8 45.0 45.0 5.1 [4.1] 192 5.5 44.7 44.7 5.1
[4.9]
[0194] Results
[0195] The octreotide content, expressed as % of nominal
concentration (see Table 2), as a function of storage time and
condition is shown in FIG. 3. The effect of changing the
counter-ion from acetate to chloride is unexpectedly high. Whereas
little change occurs for the OCT(Cl) formulation (#192) after 4
weeks at 40.degree. C., a marked degradation of octreotide in the
OCT(Ac) formulation (#174) takes place. This is even more clearly
seen in FIG. 4 where the amount of breakdown products (expressed as
% of the total Peak Area at 215 nm UV detection) is displayed as a
function of storage time and condition. In conclusion, the
stability enhancing effect of the chloride counter-ion is
surprisingly high which is extremely beneficial from a storage
stability perspective of a depot formulation product of
octreotide.
Example 7
Further Examples of Viscosity in PC/GDO Mixtures on Addition of
Co-Solvent
[0196] Mixtures of PC/GDO and co-solvent were prepared according to
the methods of Example 1 and Example 2 in the proportions indicated
in the table below.
[0197] The samples were allowed to equilibrate for several days
before viscosity measurements were performed using a Physica UDS
200 rheometer at 25.degree. C.
TABLE-US-00004 PC/GDO EtOH/ Glycerol/ H.sub.2O/ Viscosity/ Sample
(wt/wt) wt % wt % wt % mPas 1 50/50 3 -- -- 1900 2 50/50 5 -- --
780 3 50/50 7 -- -- 430 4 50/50 8 -- -- 300 5 50/50 10 -- -- 210 6
50/50 15 -- -- 100 7 45/55 3 -- -- 1350 8 45/55 5 -- -- 540 9 45/55
7 -- -- 320 10 45/55 8 -- -- 250 11 45/55 10 -- -- 150 12 45/55 15
-- -- 85 13 40/60 3 -- -- 740 14 40/60 5 -- -- 400 15 40/60 7 -- --
240 16 40/60 8 -- -- 200 17 40/60 10 -- -- 130 18 40/60 15 -- -- 57
19 40/60 -- 10 -- 8*10.sup.6 20 40/60 -- -- 3 2.5*10.sup.8 21 40/60
-- -- 5 4*10.sup.7
[0198] This example further illustrates the need for a solvent with
viscosity lowering properties in order to obtain injectable
formulations. The mixtures containing glycerol (sample 19) or water
(samples 20 and 21) are too viscous to be injectable at solvent
concentrations equivalent to the samples containing EtOH (compare
with samples 13, 14 and 17).
Sequence CWU 1
1
6114PRTArtificial SequenceSST-14DISULFID(3)..(14) 1Ala Gly Cys Lys
Asn Phe Phe Trp Lys Thr Phe Thr Ser Cys1 5 1024PRTArtificial
SequenceSST-14 Binding Sequence 2Phe Trp Lys Thr138PRTArtificial
SequenceOctreotideDISULFID(2)..(7)MOD_RES(8)..(8)X = THR-OL 3Phe
Cys Phe Trp Lys Thr Cys Xaa1 548PRTArtificial
sequenceLANREOTIDEMOD_RES(1)..(1)X =
NH2-NAPHDISULFID(2)..(7)MOD_RES(8)..(8)X = THR-CONH2 4Xaa Cys Tyr
Trp Lys Val Cys Xaa1 558PRTArtificial sequenceCYCLIC
LANREOTIDEMOD_RES(1)..(1)X =
NH2-NAPHDISULFID(2)..(7)MOD_RES(8)..(8)X = THR-CONH2 5Xaa Cys Tyr
Phe Lys Val Cys Xaa1 566PRTArtificial
sequenceSOM230MOD_RES(1)..(1)X =
PRO(2-AMINOETHYL-CARBAMATE)MOD_RES(2)..(2)X =
GLY(PHENYL)MOD_RES(5)..(5)X = TYR(METHYLPHENYL) 6Xaa Xaa Trp Lys
Xaa Phe1 5
* * * * *