U.S. patent application number 16/264275 was filed with the patent office on 2019-05-30 for dry blend formulation of tetrahydrobiopterin.
The applicant listed for this patent is BioMarin Pharmaceuticals, Inc.. Invention is credited to Tianwei Chou, Augustus O. Okhamafe.
Application Number | 20190160070 16/264275 |
Document ID | / |
Family ID | 48172694 |
Filed Date | 2019-05-30 |
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United States Patent
Application |
20190160070 |
Kind Code |
A1 |
Chou; Tianwei ; et
al. |
May 30, 2019 |
DRY BLEND FORMULATION OF TETRAHYDROBIOPTERIN
Abstract
Dry blend powder formulations comprising a pharmaceutical
formulation containing tetrahydrobiopterin, and methods of making
and using the same, are disclosed herein.
Inventors: |
Chou; Tianwei; (El Cerrito,
CA) ; Okhamafe; Augustus O.; (Concord, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BioMarin Pharmaceuticals, Inc. |
Novato |
CA |
US |
|
|
Family ID: |
48172694 |
Appl. No.: |
16/264275 |
Filed: |
January 31, 2019 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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14947482 |
Nov 20, 2015 |
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16264275 |
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13666697 |
Nov 1, 2012 |
9216178 |
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14947482 |
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61554665 |
Nov 2, 2011 |
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61622417 |
Apr 10, 2012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K 9/485 20130101;
A61P 5/50 20180101; A61K 31/519 20130101; A61P 29/00 20180101; A61P
13/12 20180101; A61K 9/4866 20130101; A61P 3/02 20180101; A61K
9/0053 20130101; A61K 9/4816 20130101; A61K 9/4858 20130101; A61P
9/00 20180101; A61K 9/4825 20130101; A61K 9/009 20130101; A61K
9/145 20130101; A61P 9/10 20180101; A61J 1/1418 20150501; A61P 7/06
20180101; A61P 9/12 20180101; A61K 31/405 20130101; A61P 25/00
20180101 |
International
Class: |
A61K 31/519 20060101
A61K031/519; A61K 9/48 20060101 A61K009/48; A61K 31/405 20060101
A61K031/405; A61K 9/00 20060101 A61K009/00; A61J 1/14 20060101
A61J001/14; A61K 9/14 20060101 A61K009/14 |
Claims
1. A pharmaceutical composition, comprising a dry blend powder of a
BH4 or BH4-related compound and an excipient.
2. The pharmaceutical composition of claim 1, wherein the amount of
the BH4 or BH4-related compound in the composition is between about
5% and about 55% by weight.
3. The pharmaceutical composition of claim 1, wherein the excipient
is a sweetening agent selected from the group consisting of
acesulfam potassium, isomalt, Magna Sweet, maltitol, mannitol,
sorbitol, sucralose, xylitol, alitmae, neohesperidin
dihydrochalcone, trehalose, tagatose, neotame, saccharin and salts
thereof, stevioside, erythritol, isomaltulose, polydextrose, luo
han guo, monatin, cyclamate, osladine, sucrose, fructose, and
glucose, and combinations thereof.
4. The pharmaceutical composition of claim 1, wherein the excipient
is a flavoring agent selected from the group consisting of cherry,
grape, orange, pink lemonade, raspberry, grape, lemon, orange,
strawberry, tutti-frutti, tangerine, apple, watermelon, pineapple,
banana, peach, kiwi, mango, mixed berry, raspberry lemonade, wild
blackberry, blue raspberry, citrus, blueberry, lime, lemon lime,
grapefruit, pomegranate, pear, and plum flavors, and combinations
thereof.
5. The pharmaceutical composition of claim 1, wherein the excipient
is a flavor enhancer selected from the group consisting of
anhydrous citric acid, citric acid monohydrate, malic acid, tartic
acid, sodium citrate, potassium citrate dihydrate, sodium potassium
tartate, ascorbic acid, and sodium ascorbate, and combinations
thereof.
6. The pharmaceutical composition of claim 1, wherein the excipient
is a filler selected from the group consisting of isomalt,
lactitol, maltitol, mannitol, sorbitol, xylitol, sucrose, and
fructose, and combinations thereof.
7. The pharmaceutical composition of claim 1, wherein the dry blend
powder comprises about 15% to about 30% of the BH4 or BH4-related
compound by weight.
8. The pharmaceutical composition of claim 1, wherein the dry blend
powder comprises about 30% to about 50% of the BH4 or BH4-related
compound by weight.
9. The pharmaceutical composition of claim 1, wherein the BH4 or
BH4-related compound is (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride.
10. The pharmaceutical composition of claim 1, wherein the BH4 or
BH4-related compound is the polymorph B form of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride.
11. The pharmaceutical composition of claim 1, wherein the BH4 or
BH4-related compound is packaged in a hermetically sealed
container.
12. The pharmaceutical composition of claim 1, wherein the BH4 or
BH4-related compound is packaged in a non-hermetically sealed
container.
13. A single chamber sachet dosage form, comprising the composition
of claim 1.
14. A dual chamber sachet dosage form, comprising the composition
of claim 1 in one chamber and a dry flavor blend in the other
chamber.
15. The sachet dosage form of claim 13, further comprising a
desiccant.
16. The sachet dosage form of claim 13, wherein the dosage is mixed
with a liquid prior to ingestion.
17. The sachet dosage form of claim 13, wherein the dosage
comprises about 5%, about 7.5%, about 10%, about 12.5%, about 15%,
about 17.5%, about 20%, about 22.5%, about 25%, about 27.5%, about
30%, about 32.5%, about 35%, about 37.5%, about 40%, about 42.5%,
about 45%, about 47.5%, about 50%, about 52.5%, or about 55% BH4
dihydrochloride by weight.
18. The sachet dosage form of claim 13, wherein the dosage
comprises between about 50 mg and about 1300 mg of the BH4 or
BH4-related compound.
19. The sachet dosage form of claim 13, wherein the dosage
comprises an additional pharmaceutical formulation.
20. The sachet dosage form of claim 13, wherein the pharmaceutical
formulation produces a clear solution when dissolved in an aqueous
solution.
21. The sachet dosage form of claim 13, wherein the sachet is a
hermetically sealed sachet.
22. The sachet dosage form of claim 13, wherein the dosage
comprises about 32% BH4 dihydrochloride, about 55.1% mannitol,
about 1.9% sucralose micronized, about 10.4% potassium citrate
monohydrate, and about 1.6% ascorbic acid fine powder by
weight.
23. The sachet dosage form of claim 13, wherein the dosage
comprises about 32% BH4 dihydrochloride, about 55.4% mannitol,
about 1.6% sucralose, about 10.4% potassium citrate, and about 1.6%
ascorbic acid by weight.
24. The sachet dosage form of claim 13, wherein the dosage
comprises about 200 mg BH4 dihydrochloride, about 338 mg mannitol,
about 12 mg sucralose micronized, about 65 mg potassium citrate
monohydrate, and about 10 mg ascorbic acid fine powder.
25. The sachet dosage form of claim 13, wherein the dosage
comprises about 100 mg BH4 dihydrochloride.
26. The sachet dosage form of claim 13, wherein no less than about
90% of the initial amount of the BH4 or BH4-related compound is
present after 3 months at 40.degree. C. and 75% Relative
Humidity.
27. The sachet dosage form of claim 13, wherein no less than about
90% of the initial amount of the BH4 or BH4-related compound is
present after 2 years at room temperature.
28. The sachet dosage form of claim 13, wherein at least about 90%
of the initial amount of the BH4 or BH4-related compound remains,
and wherein at least about 85% of the initial amount of the BH4 or
BH4-related compound dissolves within about 15 minutes, after the
sachet dosage form is stored at about 40.degree. C. and about 75%
RH for a period of about three months.
29. A stable capsule dosage form comprising a pharmaceutical
formulation comprising an initial amount of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride in a crystalline
form designated polymorph B, and one or more pharmaceutically
acceptable excipients, wherein: a. the capsule has a shell that is
essentially free of pullulan, and b. at least about 98% of the
initial amount of the tetrahydrobiopterin dihydrochloride remains
after the capsule dosage form is stored in a container at about
40.degree. C. and about 75% relative humidity for a period from
about three months to about six months.
30. The stable capsule dosage form of claim 29, wherein the
container is a heat induction-sealed, screw cap high-density
polyethylene bottle.
31. The stable capsule dosage form of claim 29, wherein the
container contains no desiccant.
32. The stable capsule dosage form of claim 29, wherein the initial
amount of the tetrahydrobiopterin dihydrochloride in the capsule
dosage form is in a range from about 100 mg to about 500 mg.
33. The stable capsule dosage form of claim 29, wherein the initial
amount of the tetrahydrobiopterin dihydrochloride in the capsule
dosage form is about 150 mg, or about 160 mg, or about 200 mg, or
about 250 mg, or about 300 mg per capsule.
34. The stable capsule dosage form of claim 29, wherein the shell
of the capsule comprises one or more substances selected from the
group consisting of cellulose derivatives; hydroxypropyl
methylcellulose; starch derivatives; carrageenans; acacia; gelatin;
polyethylene glycol; homopolymers and copolymers formed from
polyvinyl alcohol, acrylic acid, and methyl methacrylate; and
combinations thereof.
35. The stable capsule dosage form of claim 29, wherein the shell
of the capsule comprises gelatin or hydroxypropyl
methylcellulose.
36. The stable capsule dosage form of claim 29, wherein the one or
more excipients are selected from the group consisting of ascorbic
acid, silicon dioxide, mannitol, microcrystalline cellulose,
crospovidone, povidone, stearyl fumaric acid, salt forms of stearyl
fumarate, dicalcium phosphate, and 5-methyltetrahydrofolate
(5-MTHF), and salt forms thereof.
37. The stable capsule dosage form of claim 29, wherein the one or
more excipients comprise crospovidone, and stearyl fumaric acid or
a salt form of stearyl fumarate.
38. The stable capsule dosage form of claim 29, wherein the one or
more excipients further comprise ascorbic acid, silicon dioxide,
and mannitol.
39. The stable capsule dosage form of claim 29, wherein the
pharmaceutical formulation comprises an initial amount of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride in a range from
about 30% to about 60%, crospovidone from about 3% to about 6%,
sodium stearyl fumarate from about 1% to about 3%, ascorbic acid
from about 1% to about 10%, silicon dioxide from about 0.2% to
about 2%, and mannitol from about 20% to about 50% by weight of the
formulation.
40. The stable capsule dosage form of claim 29, wherein the
pharmaceutical formulation further comprises
5-hydroxytryptophan.
41. The stable capsule dosage form of claim 29, wherein the
pharmaceutical formulation comprises an initial amount of
5-hydroxytryptophan in a range from about 20% to about 40% by
weight of the formulation.
42. The stable capsule dosage form of claim 29, wherein the
pharmaceutical formulation comprises an initial amount of
(6R)-L-erythro-BH4 dihydrochloride from about 40% to about 50%,
ascorbic acid from about 40% to about 50%, crospovidone from about
3% to about 6%, sodium stearyl fumarate from about 1% to about 3%,
silicon dioxide from about 0.2% to about 2%, and calcium salt of
5-methyltetrahydrofolate from about 0.01% to about 0.5% by weight
of the formulation.
43. The stable capsule dosage form of claim 29, wherein the
pharmaceutical formulation is made by mixing the
tetrahydrobiopterin dihydrochloride and the one or more
pharmaceutically acceptable excipients, without addition of liquid
water.
44. The stable capsule dosage form of claim 29, wherein the dosage
is useful for reducing blood phenylalanine levels in patients with
hyperphenylalaninemia due to tetrahydrobiopterin-response
phenylketonuria.
45. The stable capsule dosage form of claim 29, wherein the dosage
is useful for reducing blood phenylalanine levels in patients with
hyperphenylalaninemia due to tetrahydrobiopterin-response
phenylketonuria in conjunction with a phenylalanine restricted
diet.
46. The stable capsule dosage form of claim 29, wherein the dosage
is useful for treating or ameliorating conditions associated with
elevated phenylalanine levels or decreased tyrosine or tryptophan
levels.
47. The stable capsule dosage form of claim 29, wherein the dosage
is useful for treating or ameliorating autism.
48. The stable capsule dosage form of claim 29, wherein the dosage
is useful for treating or ameliorating conditions or disorders that
would benefit from enhancement of nitric oxide synthase (NOS)
activity and subjects suffering from vascular diseases, ischemic or
inflammatory diseases, or insulin resistance.
49. The stable capsule dosage form of claim 29, wherein the dosage
is useful for treating or ameliorating the symptoms of sickle cell
disease, peripheral arterial disease, chronic kidney disease, or
hypertension.
50. The stable capsule dosage form of claim 29, comprising
administering the dosage to a mammal with food to increase
absorption of the tetrahydrobiopterin dihydrochloride.
51. The stable capsule dosage form of claim 50, wherein the food is
a high-fat, or a high-calorie, or a high-fat and high-calorie
meal.
52. The stable capsule dosage form of claim 29, wherein at least
about 90% of the initial amount of the tetrahydrobiopterin
dihydrochloride remains after the capsule dosage form is stored in
the container at about 40.degree. C. and about 75% relative
humidity for a period of three months.
53. The stable capsule dosage form of claim 29, wherein at least
about 99% of the initial amount of the tetrahydrobiopterin
dihydrochloride remains after the capsule dosage form is stored in
the container at about 40.degree. C. and about 75% relative
humidity for a period of three months.
54. The stable capsule dosage form of claim 29, wherein the initial
amount of tetrahydrobiopterin dihydrochloride remains after the
capsule dosage form is stored in the container at about 40.degree.
C. and about 75% relative humidity for a period of six months.
55. The stable capsule dosage form of claim 29, wherein at least
about 85% of the initial amount of the tetrahydrobiopterin
dihydrochloride dissolves within about 15 minutes after the capsule
dosage form is stored in the container at about 40.degree. C. and
about 75% RH for a period from about three months to about six
months, and wherein the dissolution is determined according to
U.S.P. Method II at 50 r.p.m. in 0.1 N hydrochloric acid maintained
at 37.degree. C.
56. The stable capsule dosage form of claim 29, wherein at least
about 90% of the initial amount of the tetrahydrobiopterin
dihydrochloride remains, and wherein at least about 85% of the
initial amount of the tetrahydrobiopterin dihydrochloride dissolves
within about 15 minutes, after the capsule dosage form is stored in
the container at about 40.degree. C. and about 75% RH for a period
of about three months.
57. The stable capsule dosage form of claim 29, wherein the stable
capsule dosage form is for oral administration.
58. A method of treating hyperphenylananinemia due to BH4
deficiency, wherein the hyperphenylalaninemia due to BH4 deficiency
is associated with deficiency in or reduced activity of any one or
any combination of the enzymes GTP cyclohydrolase
1,6-pyruvoyl-tetrahydropterin synthase, sepiapterin reductase,
dihydropteridine reductase, and pterin-4-carbinolamine dehydratase,
comprising administering the composition of claim 1.
59. A method of reducing blood phenylalanine levels in patients
with hyperphenylalaninemia due to tetrahydrobiopterin-responsive
phenylketonuria, comprising administering the composition of claim
1.
60. A method of reducing blood phenylalanine levels in patients
with hyperphenylalaninemia due to tetrahydrobiopterin-responsive
phenylketonuria, comprising administering the composition of claim
1.
61. A method of treating or ameliorating conditions associated with
elevated phenylalanine levels or decreased tyrosine or tryptophan
levels, comprising administering the composition of claim 1.
62. A method of treating or ameliorating autism, comprising
administering the composition of claim 1.
63. A method of treating or ameliorating conditions or disorders
that would benefit from enhancement of nitric oxide synthase (NOS)
activity or subjects suffering from vascular diseases, ischemic or
inflammatory diseases, or insulin resistance, comprising
administering the composition of claim 1.
64. A method of treating or ameliorating the symptoms of sickle
cell disease, peripheral arterial disease, chronic kidney disease,
or hypertension, comprising administering the composition of claim
1.
65. A method of administering the pharmaceutical composition of
claim 1 to a mammal with food to increase absorption of the BH4 or
BH4-related compound.
66. The method of claim 65, wherein the food is a high-fat, or a
high-calorie, or a high-fat and high-calorie meal.
67. A process for preparing a stable, dry blend powder of claim 1,
comprising: blending half of a filler with the BH4 or BH4-related
compound and a flavor enhancer in a blender to achieve an adequate
mixture; further blending a portion of the first blended mixture
with acesulfame potassium or sucralose, and ascorbic acid; passing
the second mixture through a suitable sieve; and blending the
remainder of the first mixture with the second mixture to achieve a
homogenous mixture.
68. A pharmaceutical composition of claim 1, prepared by a process
comprising: blending half of a filler with the BH4 or BH4-related
compound and a flavor enhancer in a blender to achieve an adequate
mixture; blending a portion of the first blended mixture with
acesulfame potassium or sucralose, the filler, and ascorbic acid;
passing the second mixture through a suitable sieve; and blending
the remainder of the first mixture with the second mixture to
achieve a homogenous mixture.
69. The process of claim 67, wherein the sieve is a #20 mesh
sieve.
70. The pharmaceutical composition of claim 68, wherein the sieve
is a #20 mesh sieve.
71. The process of claim 67, wherein the blender is a
V-blender.
72. The pharmaceutical composition of claim 68, wherein the blender
is a V-blender.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 14/947,482, filed Nov. 20, 2015; which is a divisional
application of U.S. application Ser. No. 13/666,697, filed Nov. 1,
2012, now U.S. Pat. No. 9,216,178; which claims the benefit of the
priority of U.S. Provisional Application Nos. 61/554,665, filed
Nov. 2, 2011; and 61/622,417, filed Apr. 10, 2012; the disclosure
of each of which is incorporated herein by reference in its
entirety.
BACKGROUND OF THE DISCLOSURE
Field of the Disclosure
[0002] This disclosure is generally directed to dry blend, powder
formulations and dosage forms of tetrahydrobiopterin. In
particular, provided is a dry blending process for
tetrahydrobiopterin (i.e., BH4 dihydrochloride), the powder of
which can be stably packaged in sachets, stable capsule dosage
forms containing a pullulan-free capsule shell, or dissolved into a
stable solution and stored in hermetically and non-hermetically
sealed containers.
Background
[0003] Tetrahydrobiopterin (also referred to as BH4 or sapropterin)
is a biogenic amine of the naturally occurring pterin family and is
a cofactor for a number of different enzymes, including
phenylalanine hydroxylase (PAH), tyrosine 3-hydroxylase, tryptophan
5-hydroxylase, and nitric oxide synthase (NOS). Accordingly, BH4 is
involved in the synthesis of the amino acids phenylalanine,
tyrosine and tryptophan, and the neurotransmitters dopamine and
serotonin. Moreover, BH4 is essential for NOS-catalyzed oxidation
of L-arginine to L-citrulline and nitric oxide. Pterins are present
in physiological fluids and tissues in reduced and oxidized forms,
but only the 5,6,7,8-tetrahydrobiopterin is biologically active.
More specifically, it is the 6R enantiomer of BH4 that is known to
be the biologically active enantiomer. For a detailed review of the
synthesis of and disorders associated with BH4, see Blau et al.,
"Disorders of tetrahydrobiopterin and related biogenic amines" in
C. R. Scriver et al., eds., The Metabolic and Molecular Bases of
Inherited Disease, 8.sup.th ed., pp. 1275-1776, McGraw-Hill (New
York, 2001).
[0004] Tetrahydrobiopterin is unstable, readily undergoes aerobic
oxidation at room temperature, and has a shelf-life of less than 8
hours at room temperature in aqueous solutions. Due to the
instability of BH4, most tetrahydrobiopterin products available on
the market need to be specially packaged or kept frozen. The
instability of such BH4 compositions is undesirable, and
significant degradation resulting from improper storage could
hinder therapy of patients. One example of a stable BH4 tablet
composition is disclosed in WO 2006/055511, which is incorporated
herein by reference in its entirety. Such a tablet composition is
sold under the tradename KUVAN.RTM.. There is a need for additional
formulations of BH4 suitable for pharmaceutical use.
SUMMARY
[0005] Provided herein is a stable dry blend formulation of
tetrahydrobiopterin (BH4) or a BH4-related compound, stable dosages
in the form of capsule dosages or dry powder sachet dosages, and
therapeutic methods using such dosage forms.
[0006] In one aspect of the disclosure, provided herein is a stable
dry blend formation of BH4 or a BH4-related compound. In one
embodiment, the formulation comprises a dry blend of BH4 or a
BH4-related compound, a flavor enhancer, a sweetener, and one or
more fillers wherein the components are blended together. In
certain embodiments, the blending comprises blending the fillers
with the BH4 or BH4 compound and flavor enhancer in a blender to
achieve a adequate mixture, further blending a portion of the
blended mixture with acesulfame potassium or sucralose, a flavoring
agent, and ascorbic acid and thereafter passing that mixture
through a suitable sieve, and lastly blending the second mixture
with the remainder of the first mixture until the blend is
homogenous.
[0007] In certain embodiments, the BH4 or a BH4-related compound is
(6R)-L-erythro-5,6,7,8-tetrahydrobiopterin dihydrochloride (i.e.,
"BH4 dihydrochloride" or " sapropterin dihydrochloride").
[0008] In certain embodiments for example, the fillers are isomalt,
lactitol, maltitol, mannitol, sorbitol, xylitol, sucrose, fructose,
or combinations thereof
[0009] In certain embodiments, for example, the dry blend
formulation also contains a sweetener wherein the sweetener is
acesulfame potassium, isomalt, Magna Sweet, maltitol, mannitol,
sorbitol, sucralose, xylitol, alitmae, neohesperidin
dihydrochalcone, trehalose, tagatose, neotame, saccharin and salts
thereof, stevioside, erythritol, isomaltulose, polydextrose, luo
han guo, monatin, cyclamate, osladine, sucrose, fructose, or
glucose or combinations thereof.
[0010] In certain embodiments, for example, the flavor enhancer is
anhydrous citric acid, citric acid monohydrate, malic acid, tartic
acid, sodium citrate, potassium citrate monohydrate, potassium
citrate anhydrous, or sodium potassium tartate, ascorbic acid,
sodium ascorb ate, or combinations thereof.
[0011] In certain embodiments, for example, the flavoring agent is
a cherry, grape, orange, pink lemonade, raspberry, grape, lemon,
orange, strawberry, tutti-frutti, tangerine, apple, watermelon,
pineapple, banana, peach, kiwi, mango, mixed berry, raspberry
lemonade, wild blackberry, blue raspberry, citrus, blueberry, lime,
lemon lime, grapefruit, pomegranate, pear, or plum flavors, bubble
gum, or combinations thereof.
[0012] In certain embodiments, for example, the sieve is a 20 mesh
sieve.
[0013] In another embodiment, the dry blend formulation is
dissolved in an aqueous solution, flushed with an inert gas, and
hermetically sealed wherein the active solution remains stable.
[0014] In another aspect of the disclosure, stable BH4 or
BH4-related compounds can optionally include one or more other
therapeutic agents suitable for the condition to be treated. In one
embodiment, the other therapeutic agents are selected from folates,
including but not limited to folate precursors, folic acids, and
folate derivatives, e.g., folinic acid (leucovorin); vitamins, such
as vitamin C (ascorbic acid), vitamin B2 (riboflavin), and vitamin
B12; neurotransmitter precursors, such as L-dopa, carbidopa, and
serotonin; 5-hydroxytryptophan; arginine; and combinations
thereof
[0015] In another aspect of the disclosure, provided herein are
therapeutic methods using the stable dosage forms described herein.
The stable dosage forms are useful for treating, ameliorating, or
preventing any BH4-responsive conditions or disorders, e.g.,
metabolic disorders involving amino acid metabolism. In one
embodiment, the stable dosage forms are used to treat subjects
exhibiting elevated phenylalanine levels or decreased tyrosine
levels, e.g., subjects suffering from hyperphenylalanemia, mild
phenylketonuria (PKU), or classic severe PKU. In another
embodiment, the stable dosages are used to treat subjects suffering
from conditions or disorders that would benefit from enhancement of
nitric oxide synthase activity, including, but not limited to,
vascular diseases, ischemic or inflammatory diseases, diabetes, and
insulin resistance. The total dose of BH4 or BH4-related compound
required can be administered in multiple doses or in a single dose.
The dosage forms can be administered daily or at some other
interval, e.g., every alternative day or weekly.
[0016] In another aspect of the disclosure, the stable dosage forms
can be used for treating or ameliorating autism. In one embodiment,
the BH4 or BH4-related compound can be used for treating or
ameliorating autism in children. In one embodiment, the BH4 or
BH4-related compound can be used for treating or ameliorating
autism in adults. In a particular embodiment, the BH4 or
BH4-related compound can be administered in conjunction with a
second pharmaceutical composition to treat or ameliorate the
symptoms of autism. In a particular embodiment, the second
pharmaceutical compound for the combination treatment can be
selected from groups consisting of stimulants, antidepressants,
antianxiety medications, non-stimulant ADHD medications,
antipsychotics, mood stabilizers, or Alzheimer's medications.
[0017] In another aspect of the disclosure, the stable dosage forms
can be used alone or in conjunction with other therapies suitable
for treating the particular condition or disorder, including the
underlying disease or clinical symptoms thereof. For example, for
treatment of PKU or BH4 deficiency, the dosage forms disclosed
herein can be administered in combination with a protein-restricted
diet, e.g., where the subject is limited to about 600 mg or less,
or about 300 mg or less of protein daily, and the subject
optionally is given supplements of amino acids, such as tyrosine,
valine, tryptophan, isoleucine, and/or leucine. The dosage forms
can also be administered in combination with folates, arginine,
vitamins, or neurotransmitter precursors, or combinations thereof.
As another example, for vascular diseases, diabetes, or insulin
resistance, the dosage forms described herein can be administered
in conjunction with other therapeutic agent(s), such as
anti-hypertensive agents, anti-platelet agents,
cholesterol-lowering agents, insulin, or oral hypoglycemic
agents.
[0018] In another aspect of the disclosure, provided herein are
stable capsule dosage forms, which comprise a pharmaceutical
formulation containing BH4 or a BH4-related compound that maintains
its stability for an extended period of time. In one embodiment,
the formulation comprises a crystalline (e.g., powder) form of BH4
that is stable at room temperature for more than 8 hours, and a
pharmaceutically acceptable carrier, diluent, or excipient. In
certain embodiments, the stable capsules provided herein, in which
BH4 exhibits unexpected stability, have a projected shelf-life of
at least 2 years at room temperature. In another embodiment, the
formulation comprises at least about 40% of BH4 or a BH4-related
compound by weight of the formulation.
[0019] In a further embodiment, the stable capsule dosage forms
comprise a pharmaceutical formulation containing BH4 or a
BH4-related compound and one or more pharmaceutically acceptable
excipients. In one embodiment, the excipients are selected from
binders, fillers, diluents, disintegrants, glidants, acidic
antioxidants, lubricants, and combinations thereof. In certain
embodiments, the formulation includes mannitol, crospovidone,
ascorbic acid, sodium stearyl fumarate, and silicon dioxide. In
another embodiment, the formulation contains microcrystalline
cellulose.
[0020] In another embodiment, the stable capsule dosage forms are
stored without desiccant wherein the BH4 or BH4-related compound
remains active within the stable capsules in the absence of
desiccant.
[0021] In another aspect of the disclosure, provided herein are
stable sachet dosage forms, which comprise a pharmaceutical
formulation containing BH4 or a BH4-related compound that maintains
its stability for an extended period of time. Sachet, for example,
refers to a small bag or packet wherein the small bag or packet
contains the BH4 or BH4-related compound dosage. Sachets are well
known in the art and one of ordinary skill will understand the full
breadth of the term.
[0022] In one embodiment, the sachet is a single chamber sachet. In
another embodiment, the sachet is a double stick/dual chamber
sachet wherein the dual chamber stick pack separates incompatible
powder components (e.g., Twin Stick Dual Chamber Stick Pack Design
from Packing Technologies and Inspection, LLC). In another
embodiment, one chamber contains the active BH4 or a BH4-related
compound dry blend and the other contains the dry flavor blend. In
another embodiment, the powders from both chambers can be mixed and
diluted with a liquid prior to oral ingestion.
[0023] In another embodiment, the BH4 or BH4-related compound dry
powder blend is dissolved in an aqueous solution prior to
ingestion. In a specific embodiment, the dry blend powder is clear
when dissolved (i.e., the solution is not cloudy).
[0024] In another embodiment, the dual chamber sachet is packaged
in foil pouches. In another embodiment the BH4 or BH4-related
compound is stable for at least 3 months at room temperature. In
another embodiment, the projected shelf-life is at least 2 years at
room temperature.
[0025] In further embodiments, the dual chamber sachets comprise a
pharmaceutical formulation containing BH4 or a BH4-related compound
and one or more pharmaceutically acceptable excipients. In one
embodiment, the excipients are selected from flavor enhancers,
flavoring agents, sweeteners, fillers, diluents, glidants,
anti-oxidants, and combinations thereof. In one specific
embodiment, the excipients can improve stability and
manufacturability of the dry blend. In other embodiments, the
fillers may be selected from the non-exclusive list consisting of,
for example, isomalt, lactitol, maltitol, mannitol, sorbitol,
xylitol, sucrose, and fructose. For the compositions and methods
described herein, particular features of the disclosure, such as
components, ranges thereof, in compositions, conditions and steps,
can be selected from the various embodiments and examples described
herein.
[0026] In another embodiment, such methods involve administering
BH4, whether swallowed as a solid or semisolid dosage form, or
dissolved in a liquid, with food, e.g., a high-fat food or a
high-fat and/or high-calorie meal. In another embodiment, BH4,
whether swallowed or dissolved, is administered at a specified time
including but not limited to morning, day, night, same time of the
day, with food, e.g., a high-fat food or a high-fat and/or
high-calorie meal, one or more times a day. In another embodiment,
BH4 is ingested once daily as a solid dosage form just after meals.
In another embodiment the solid dosage form is a formulated tablet
or capsule. In more exemplary embodiments, BH4 is ingested within
approximately 0 to 30 minutes, or 5 to 20 minutes, of eating a
meal.
[0027] Other features and advantages of the disclosure will become
apparent from the following detailed description. It should be
understood, however, that the detailed description and the specific
examples, while indicating particular embodiments of the
disclosure, are given by way of illustration only, and various
changes and modifications within the spirit and scope of the
disclosure will become apparent to those skilled in the art from
the detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a graph of the characteristic X-ray diffraction
pattern exhibited by polymorphic form B of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride.
[0029] FIGS. 2 and 3 show dissolution profiles (the rate of
dissolution of BH4 dihydrochloride from the solid dosage forms
according to U.S.P. Method II at 50 r.p.m. in 0.1 N hydrochloric
acid at 37.degree. C.) after the HPMC and gelatin capsules have
been stored for various periods of time at 40.degree. C. and about
75% relative humidity. Polymorph B of BH4 dihydrochloride was used
in both studies.
[0030] FIG. 4 compares the stability of BH4 capsules stored in
high-density polyethylene (HDPE) bottles or HDPE bottles sealed in
foil pouches at 40.degree. C. and 75% relative humidity to the
stability of BH4 tablets stored in HDPE bottles or foil blister
cards under the same conditions. Polymorph B of BH4 dihydrochloride
was used in all of these studies.
[0031] FIG. 5 depicts the dissolution profile of 160 mg BH4
dihydrochloride (polymorph B) contained in HPMC capsules after the
capsules have been stored for 1 month at 25.degree. C. and about
60% relative humidity, and alternatively at 40.degree. C. and about
75% relative humidity.
[0032] FIG. 6 illustrates the dissolution profile of 200 mg BH4
dihydrochloride (polymorph B) contained in HPMC capsules after the
capsules have been stored for 3 months at 40.degree. C. and about
75% relative humidity.
[0033] FIG. 7 displays the dissolution profile of 200 mg BH4
dihydrochloride (polymorph B) contained in HPMC capsules after the
capsules have been stored in HDPE bottles containing varying
amounts of silica gel desiccant for 3 months at 40.degree. C. and
about 75% relative humidity.
[0034] FIG. 8 shows the dissolution profile of 250 mg BH4
dihydrochloride (polymorph B) contained in HPMC capsules after the
capsules have been stored for 1 month at 25.degree. C. and about
60% relative humidity, and alternatively at 40.degree. C. and about
75% relative humidity.
[0035] FIG. 9 shows the appearance of hydroxypropyl methylcellulose
("HPMC") capsule contents after 6 months of storage at 40.degree.
C. and 5% relative humidity ("RH").
DETAILED DESCRIPTION
[0036] A first aspect of the disclosure is a stable, dry blend
formulation of BH4 or a BH4-related compound. In one embodiment,
the stable dry blend formulation is achieved by mixing a BH4 or
BH4-related compound with a filler, flavoring agent, and flavor
enhancer in a blender and passed through a sieve. In certain
embodiments, a filler, a BH4 or BH4-related compound, and flavoring
agent is blended together first, thereafter a portion of the
mixture is further blended with acesulfame potassium or sucralose,
a flavoring agent, and ascorbic acid, then passed through a
suitable sieve, mixed with the remaining portion of the initial
blend, and then blended until the mixture is homogenous.
[0037] Another aspect of the disclosure are stable dosage forms
that maintain the stability of a hygroscopic, moisture-sensitive
active ingredient over time. In one embodiment, the active BH4 or a
BH4-related compound is in the form of an anhydrous polymorph of
(6R)-L-erythro-5,6,7,8-tetrahydrobiopterin dihydrochloride (i.e.,
"BH4 dihydrochloride" or "sapropterin dihydrochloride") that is
stable at room temperature to atmospheric oxygen and normal
humidity, described herein as polymorph B. Under certain conditions
in which moisture is present (e.g., percent relative humidity above
about 80% or a moisture-containing dosage form), polymorph B begins
to absorb water, and thereby loses its crystalline form (i.e.,
becomes amorphous) and becomes labile to oxidation. BH4
dihydrochloride is hygroscopic. Following moisture absorption or
dissolution in the presence of water, BH4 dihydrochloride becomes
labile to oxidation. The main oxidative degradation product of BH4
is dihydrobiopterin (BH2), which in turn gets oxidized to
biopterin.
[0038] Another aspect of the disclosure are stable dosage forms
made from dry blending wherein the dry blending does not expose the
active BH4 or BH4-related compound to moisture. Compared to wet
blending formulations which can degrade the stable crystalline
polymorph B formulation, dry blending can result in less
degradation. Furthermore, the active pharmaceutical ingredient,
i.e., the BH4 or BH4-related compound, of the dry blend powder
retains its crystalline form throughout the dry blending process,
in contrast to state changes resulting from a wet blending
process.
[0039] Tetrahydrobiopterin dihydrochloride would be expected to
exhibit decreased stability if formulated in capsules. However,
conventional capsule shells contain some amount of water. For
example, capsule shells made of gelatin typically contain around 10
weight % water, and capsule shells made of hydroxypropyl
methylcellulose (HPMC) typically contain about 4 to 6 weight %
water. Gelatin capsules are expected to transfer moisture from the
capsule shell to the formulation loaded into the capsule,
particularly if the formulation contains a hygroscopic ingredient
(see, e.g., R. Chang et al., J. Pharm. Sci., 87: 556-558 (1998)).
The loss of water from the capsule shell can cause the gelatin
capsules to become brittle and fracture easily (Chang et al., id.).
More importantly, US 2004/0043064 teaches that the moisture
transmitted from the gelatin capsule shell to the formulation
"result[s] in any number of problems, including degradation" of the
active ingredient and reduction of its shelf-life. Moreover, US
2004/0043064 teaches that capsules made of "a cellulose-based
ether, such as hydroxypropyl methylcellulose, . . . still allow for
the permeation of moisture," and thus "are less than optimal since
moisture transmission is often not sufficiently reduced."
[0040] For hygroscopic, moisture-sensitive active ingredients such
as BH4 dihydrochloride, a capsule dosage form normally is not
recommended because the active ingredient would be expected to
absorb water from the material (e.g., gelatin or HPMC) in the
capsule shell and thereby become unstable (e.g., labile to
oxidation in the case of BH4 dihydrochloride). Contrary to
conventional wisdom, stable capsule dosage forms, in which BH4
dihydrochloride has unexpected stability and prolonged shelf-life
despite storage of such capsules at elevated temperature and high
humidity in the absence of a desiccant, have been developed and are
disclosed herein. It is particularly unexpected that the active
pharmaceutical ingredient, i.e., BH4 or a BH4-related compound,
within the capsule remains stable when stored in the absence of
desiccant.
[0041] Another aspect of the disclosure are stable sachet dosage
forms. Dry powder blends of BH4 and BH4-related compounds have
unexpected physical stabilities and blend uniformities. In another
embodiment, the sachet is a single chamber sachet. In another
embodiment, the sachet is a dual chamber sachet. In another
embodiment, the dual chamber sachet is used to separate
incompatible components. In a specific embodiment, the sachet is
used to prevent moisture from contacting the dry, stable BH4 or
BH4-related dry blend compound.
[0042] In certain embodiments, the BH4 or a BH4-related compound in
the sachet is BH4 dihydrochloride. In another particular
embodiment, the sweetener is acesulfam potassium, isomalt, Magna
Sweet, maltitol, mannitol, sorbitol, sucralose, xylitol, alitmae,
neohesperidin dihydrochalcone, trehalose, tagatose, neotame,
saccharin and salts thereof, stevioside, erythritol, isomaltulose,
polydextrose, luo han guo, monatin, cyclamate, osladine, sucrose,
fructose, or glucose or combinations thereof; the flavor enhancer
is anhydrous citric acid, citric acid monohydrate, malic acid,
tartic acid, sodium citrate, potassium citrate
dehydratemonohydrate, potassium citrate anhydrous, or sodium
potassium tartate or combinations thereof; the flavoring agent is a
cherry, grape, orange, pink lemonade, raspberry, grape, lemon,
orange, strawberry, tutti-frutti, tangerine, apple, watermelon,
pineapple, banana, peach, kiwi, mango, mixed berry, raspberry
lemonade, wild blackberry, blue raspberry, citrus, blueberry, lime,
lemon lime, grapefruit, pomegranate, pear, or plum flavors or
combinations thereof; and the sieve is a 20 mesh sieve.
[0043] In another embodiment, one chamber of the dual chamber
sachet may contain the active BH4 or a BH4-related stable powder
dry blend compound and the second chamber may contain the flavor
blend which, if packaged together could decrease the stability
and/or appearance of the active BH4 or BH4-related compound.
Accordingly, the dry powder blend of BH4 dihydrochloride in a dual
chamber sachet dosage has unexpected stability and prolonged
shelf-life have been developed and are disclosed herein.
[0044] In another embodiment, the sachets are sealed in Mylar foil
pouches. In another specific embodiment, the sachets contain a
desiccant. In certain embodiments, the desiccant is, for example, a
montmorillonite clay, a silica gel, an indicating silica gel, a
molecular sieve, calcium oxide, calcium sulfate, activated alumina,
aerogel, benzophenone, bentonite clay, calcium chloride, calcium
hydride, cobalt(II) chloride, copper(II) sulfate, lithium chloride,
lithium hydride, lithium bromide, magnesium, magnesium sulfate,
magnesium perchlorate, a sodium-potassium alloy, phosphorus
pentachloride, phosphorus pentoxide, potassium, potassium
carbonate, sodium, sodium chlorate, sodium chloride, sodium
hydride, sodium hydroxide, sodium sulfate, sodium-benzophenone,
sucrose, or sulfuric acid or any combinations thereof. In another
embodiment, the Mylar foil pouches contain a desiccant.
Definitions
[0045] Generally, the nomenclature used herein and the laboratory
procedures in organic chemistry, medicinal chemistry, and
pharmacology described herein are those well known and commonly
employed in the art. Unless defined otherwise, all technical and
scientific terms used herein generally have the same meaning as
commonly understood by one of ordinary skill in the art to which
this disclosure belongs.
[0046] As used in the specification and the accompanying claims,
the indefinite articles "a" and "an" and the definite article "the"
include plural as well as singular referents, unless the context
clearly dictates otherwise.
[0047] The term "about" or "approximately" means an acceptable
error for a particular value as determined by one of ordinary skill
in the art, which depends in part on how the value is measured or
determined. In certain embodiments, the term "about" or
"approximately" means within 1, 2, 3, or 4 standard deviations. In
certain embodiments, the term "about" or "approximately" means
within 30%, 25%, 20%, 15%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%,
0.5%, 0.1%, or 0.05% of a given value or range.
[0048] As used herein, the terms "BH4", "tetrahydrobiopterin,"
"sapropterin," and "SAP" are used interchangeably and encompass
(6R)-L-erythro-5,6,7,8-tetrahydrobiopterin, and polymorphs,
tautomers, pharmaceutically acceptable salts, and solvates thereof,
unless expressly indicated otherwise. The term "BH4-related
compound" encompasses analogs, derivatives, prodrugs, and
precursors of BH4, as well as pharmaceutically acceptable salts of
BH4, unless expressly indicated otherwise.
[0049] The term "subject" refers to an animal, including but not
limited to, a mammal, such as a primate (e.g., human or monkey),
cow, sheep, goat, pig, horse, dog, cat, rabbit, rat, or mouse. The
terms "subject" and "patient" are used interchangeably herein in
reference, e.g., to a mammalian subject, such as a human
subject.
[0050] The terms "treat," "treating," and "treatment" encompass
alleviating or abrogating a condition, disorder, or disease, or one
or more of the symptoms associated with the condition, disorder, or
disease, and encompass alleviating or eradicating the cause(s) of
the condition, disorder, or disease itself. In one embodiment, the
terms "treat," "treating," and "treatment" refer to administration
of a compound, a pharmaceutical composition, or a pharmaceutical
dosage form provided herein to a subject for purposes of
alleviating, abrogating, or preventing a condition, disorder, or
disease, or symptom(s) associated therewith, or cause(s)
thereof.
[0051] The terms "prevent," "preventing," and "prevention"
encompass delaying and/or precluding the onset of a condition,
disorder, or disease, and/or its attendant symptom(s); barring a
subject from acquiring a disease; and reducing a subject's risk of
acquiring a condition, disorder, or disease.
[0052] The term "therapeutically effective amount" encompasses the
amount of a compound that, when administered, is sufficient to
prevent development of, or alleviate to some extent, one or more of
the symptoms of the condition, disorder, or disease being treated.
The term "therapeutically effective amount" also encompasses the
amount of a compound that is sufficient to elicit the biological or
medical response of a cell, tissue, system, animal, or human, which
is being sought by a researcher, veterinarian, medical doctor, or
clinician.
[0053] In an embodiment, each component of a pharmaceutical
formulation is "pharmaceutically acceptable" in the sense of being
compatible with the other ingredients of the formulation, and being
suitable for use in contact with cells, tissues, or organs of
animals or humans without excessive toxicity, irritation, allergic
response, immunogenicity, or other adverse reactions, in the amount
used in the dosage form according to the dosing schedule, and
commensurate with a reasonable benefit/risk ratio.
[0054] The terms "pharmaceutically acceptable carrier" and
"pharmaceutically acceptable excipient" encompass pharmaceutically
acceptable materials, compositions, and vehicles, such as liquid
fillers, solid fillers, diluents, excipients, solvents, and
encapsulating materials. Excipients also include all
pharmaceutically acceptable dispersion media, coatings, isotonic
agents, absorption delaying agents, antimicrobial agents,
antibacterial agents, antifungal agents, adjuvants, and so on. The
use of such media and agents in pharmaceutical formulations is well
known in the art. Except insofar as any conventional carrier or
excipient is incompatible with the active ingredient, the present
disclosure encompasses the use of conventional carriers and
excipients in the formulations and dosage forms described herein.
See, e.g., Remington: The Science and Practice of Pharmacy, 21st
Ed., Lippincott Williams & Wilkins (Philadelphia, Pa., 2005);
Handbook of Pharmaceutical Excipients, 5th Ed., Rowe et al., Eds.,
The Pharmaceutical Press and the American Pharmaceutical
Association (2005); Handbook of Pharmaceutical Additives, 3rd Ed.,
Ash and Ash, Eds., Gower Publishing Co. (2007); and Pharmaceutical
Preformulation and Formulation, Gibson, Ed., CRC Press LLC (Boca
Raton, Fla., 2004).
[0055] The term "dry blend powder" encompasses powders formed from
granules without moisture. A "dry blend powder" is a powder that is
a homogenous blend suitable for automated sachet filling, stable in
a non-hermetically sealed container, and able to dissolve in an
aqueous liquid to produce a clear and/or transparent solution. For
clarity, a "dry blend powder" is distinct from a wet blending
product (i.e., wet milling) because the active pharmaceutical
ingredient ("API") retains its crystalline form throughout the dry
blend manufacturing process whereas wet blending results in loss of
crystalline form of the API, particularly water soluble APIs such
as BH4 or a BH4-related compound, during the manufacturing
process.
[0056] The term "stable" encompasses a pharmaceutical compound or
composition that retains greater than or equal to 90% of its
initial potency after 3 months of storage at 40.degree. C. and 75%
Relative Humidity ("RH").
[0057] The term "dry blend flavor" encompasses a powder blend
prepared by mixing dry ingredients of sapropterin dihydrochloride,
sweetener, flavoring agent and flavor enhancer to form a uniform
blend. The dry flavor blend quickly dissolves in water without heat
and improves the palatability of sapropterin dihydrochloride.
[0058] As used herein, the term "bioavailability" refers to the
fraction of an administered dose of a drug entering systemic
circulation. If the drug were administered intravenously, then its
bioavailability theoretically would be 100%. However, if the drug
were administered via other routes (such as orally), then its
bioavailability would be less than 100% as a result of, for
example, incomplete absorption in the GI tract, degradation or
metabolism prior to absorption, and/or hepatic first pass
effect.
[0059] The term "high fat meal" refers generally to a meal of at
least about 700 kcal and at least about 45% fat (relative
percentage of kcal which are fat), or alternatively at least about
900 kcal and at least about 50% fat. The term "high fat food"
refers generally to a food comprising at least 20 g of fat, or at
least 25, 30, 35, 40, 45, or 50 g of fat, and/or at least about 45%
or 50% fat. In another embodiment, a "high-fat meal" contains fat
as approximately 50% of total caloric content of the meal. In
another embodiment, a "high-calorie meal" contains approximately
800 to 1000 calories. In certain embodiments, a high-fat and
high-calorie meal is used as a test meal for food-effect
bioavailability and fed bioequivalence studies. This test meal may
derive approximately 150, 250, and 500-600 calories from protein,
carbohydrate and fat, respectively. An example test meal consists
of two eggs fried in butter, two strips of bacon, four ounces of
hash brown potatoes and eight ounces of whole milk. Substitution is
possible if a similar amount of calories from protein,
carbohydrate, and fat has comparable meal volume and viscosity
(Guidance for Industry, Food-Effect Bioavailability and Fed
Bioequivalence Studies, U.S. Department of Health and Human
Services, Food and Drug Administration, Center for Drug Evaluation
and Research (CDER), December 2002).
Synthesis of BH4 and BH4-Related Compounds
[0060] A variety of methods is known in the art for synthesis of
tetrahydrobiopterins and precursors, derivatives, and analogs
thereof. The following publications describe methods of making
dihydrobiopterins, BH4 and derivatives thereof which can be used
for the present disclosure: U.S. Pat. Nos. 2,601,215; 3,505,329;
4,540,783; 4,550,109; 4,587,340; 4,595,752; 4,649,197; 4,665,182;
4,701,455; 4,713,454; 4,937,342; 5,037,981; 5,198,547; 5,350,851;
5,401,844; and 5,698,408; Canadian Application Publication No. CA
2,420,374; European Application Nos. EP 079574 and EP 191335;
Suntory Japanese Patent Publications Nos. JP 4-082888, JP
59-021685, and JP 9-157270; Sugimoto and Matsuura, Bull. Chem. Soc.
Jp., 48(12): 3767-3768 (1975); Sugimoto and Matsuura, Bull. Chem.
Soc. Jp., 52(1): 181-183 (1979); Matsuura et al., Chem. Lett. Jp.,
735-738 (1984); Matsuura et al., Heterocycles, 23(12): 3115-3120
(1985); and Whiteley et al., Anal. Biochem., 137(2): 394-396
(1984), each of which is incorporated herein by reference in its
entirety. The following publications describe methods of
synthesizing BH4 which can be used for the present disclosure: WO
2005/049614; U.S. Patent No. 4,540,783; Japanese Patent No.
59-021685; Schircks et al., Helv. Chim. Acta, 60: 211 (1977);
Sugimoto et al., Bull. Chem. Soc. Jp., 52(1): 181 (1979); Sugimoto
et al., Bull. Chem. Soc. Jp., 48(12): 3767 (1975); Viscontini et
al., Helv. Chim. Acta, 52: 1225 (1969); and Matsuura et al., Chem.
Lett., 735 (1984), each of which is incorporated herein by
reference in its entirety.
[0061] Non-limiting examples of analogs of BH4 that can be used in
the formulations, stable capsules, and methods described herein
include pteridine, pterin, neopterin, biopterin,
7,8-dihydrobiopterin, 6-methyltetrahydropterin, other 6-substituted
tetrahydropterins, sepiapterin, 6,7-dimethyltetrahydropterin,
6-methyl biopterin, other 6-substituted biopterins, and other
analogs that are described in the art. Non-limiting examples of
derivatives of BH4 that can be used in the formulations, stable
capsules, and methods described herein include the derivatives
described in U.S. Pat. Nos. 2,541,717; 2,603,643; 2,955,110;
4,371,514; 4,758,571; 4,774,244; 5,902,810 and 6,162,806, each of
which is incorporated herein by reference in its entirety.
[0062] Any of the methods disclosed in the aforementioned
publications or other suitable methods can be used to produce BH4,
or precursors, derivatives, or analogs thereof, for use in the
dosage forms and therapeutic methods described herein.
Crystalline Polymorphs of (6R)-Tetrahydrobiopterin Hydrochloride
Salt
[0063] BH4, and in particular the dihydrochloride salt of BH4,
exhibits crystalline polymorphism. The structure of
(6R)-L-erythro-5,6,7,8-tetrahydrobiopterin is:
##STR00001##
The (6R) form of BH4 is the known biologically active form.
[0064] BH4 is unstable at ambient temperature and difficult to
handle. The dihydrochloride salt of BH4 is known to be more stable
and easier to handle than the free base (U.S. Application
Publication No. 2006/0035900, which is incorporated herein by
reference in its entirety). Results obtained during development of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride indicated that
the compound can exist in different crystalline forms, including
polymorphic forms and solvates.
[0065] The crystalline polymorph of BH4 dihydrochloride that has
been found to be the most stable is referred to herein as "form B",
or "polymorph B". Polymorph B is a slightly hygroscopic anhydrate
with the highest thermodynamic stability, above about 20.degree. C.
Furthermore, form B can be easily processed and handled due to its
thermal stability and high melting point, near 260.degree. C.
(.DELTA.H.sub.f>140 J/g). These properties render polymorph form
B suitable for pharmaceutical formulations, which may be prepared
at elevated temperatures. Polymorph B can be obtained as a fine
powder with a particle size that may range from 0.2 .mu.m to 500
.mu.m.
[0066] Form B of BH4 dihydrochloride exhibits an X-ray powder
diffraction pattern having peaks at, expressed in d-values (A): 8.7
(vs), 6.9 (w), 5.90 (vw), 5.63 (m), 5.07 (m), 4.76 (m), 4.40 (m),
4.15 (w), 4.00 (s), 3.95 (m), 3.52 (m), 3.44 (w), 3.32 (m), 3.23
(s), 3.17 (w), 3.11 (vs), 3.06 (w), 2.99 (w), 2.96 (w), 2.94 (m),
2.87 (w), 2.84 (s), 2.82 (m), 2.69 (w), 2.59 (w), 2.44 (w). FIG. 1
is a graph of the characteristic X-ray powder diffraction pattern
exhibited by form B of (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride. As used herein, the following abbreviations in
brackets mean: (vs)=very strong intensity, (s)=strong intensity,
(m)=medium intensity, (w)=weak intensity, and (vw)=very weak
intensity.
[0067] All crystalline forms (including polymorphs, hydrates, and
solvates), including form B, can be used for the preparation of
polymorph B. For example, polymorph B can be obtained by phase
equilibration of suspensions of amorphous or polymorphic forms of
BH4, such as polymorph A, in suitable polar and non aqueous
solvents. In one embodiment, the pharmaceutical preparations
described herein comprise polymorph form B of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride.
[0068] Other forms of BH4 can be converted to form B in other ways,
e.g., by dispersing the other form of BH4 in a solvent at room
temperature, stirring the suspension at ambient temperature for a
time sufficient to produce polymorph form B, thereafter isolating
crystalline form B, and removing the solvent from the isolated form
B. Ambient temperature, as used herein, means temperature in a
range from about 0.degree. C. to about 60.degree. C., e.g., from
about 15.degree. C. to about 40.degree. C. The applied temperature
can be changed during the preparation process by decreasing or
increasing the temperature stepwise or continuously. Suitable
solvents for the conversion of other forms to form B include, but
are not limited to, methanol, ethanol, isopropanol, other C.sub.3-
and C.sub.4-alcohols, acetic acid, acetonitrile, tetrahydrofuran,
methyl-t-butyl ether, 1,4-dioxane, ethyl acetate, isopropyl
acetate, other C.sub.3-C.sub.6-acetates, methyl ethyl ketone, and
other methyl C.sub.3-C.sub.5 alkyl ketones. The time to complete
phase equilibration may be up to 30 hours, e.g., up to 20 hours or
less than 20 hours.
[0069] Polymorph B can also be obtained by crystallization from
solvent mixtures containing up to about 5% water, e.g., from
mixtures of ethanol, acetic acid, and water. Polymorph B of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride can be prepared
by dissolution, optionally at elevated temperatures, e.g., of a
solid of lower energy form than form B or of form B of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride in a solvent
mixture comprising ethanol, acetic acid and water; addition of
seeds to the solution; cooling the obtained suspension; and
isolation of the formed crystals. Dissolution can be carried out at
room temperature, up to about 70.degree. C., or up to about
50.degree. C. The composition of the solvent mixture may comprise a
volume ratio of water:acetic acid:tetrahydrofuran of about 1:3:2 to
about 1:9:4, e.g., about 1:5:4. The solution can optionally be
stirred. Cooling means cooling to a temperature in the range from
about -40.degree. C. to about 30.degree. C., e.g., from about
10.degree. C. to about 30.degree. C., or from about 0.degree. C. to
about 10.degree. C. Suitable seeds are polymorph B from another
batch or crystals having a similar or identical morphology. After
isolation, the crystalline form B can be washed with a non-solvent,
such as acetone or tetrahydrofuran, and dried in the usual
manner.
[0070] Polymorph B can also be obtained by crystallization from
aqueous solutions through the addition of non-solvents, such as
methanol, ethanol, and acetic acid. The crystallization and
isolation procedure can be advantageously carried out at room
temperature without cooling the solution. This process is therefore
particularly suitable to be carried out in industrial scale.
[0071] In one embodiment, a composition comprising polymorph B of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride is prepared by
dissolving form B, or a solid form other than form B, of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride in water at
ambient temperature, adding a non-solvent in an amount sufficient
to form a suspension, optionally stirring the suspension for a
certain time, and thereafter isolating the formed crystals. The
composition is further modified into a pharmaceutical composition
as described below.
[0072] The concentration of (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in the aqueous solution may be from about 10% to
about 80% by weight, e.g., from about 20% to about 60% by weight,
by reference to the solution. Non-limiting examples of suitable
non-solvents (solvents useful in preparing suspensions of BH4)
include methanol, ethanol, and acetic acid. The non-solvent may be
added to the aqueous solution. Alternatively, the aqueous solution
may be added to the non-solvent. The stirring time after formation
of the suspension may be up to 30 hours, e.g., up to 20 hours or
less than 20 hours. Isolation by filtration and drying is carried
out in known manner as described above.
[0073] Polymorph B of BH4 dihydrochloride is a very stable
crystalline form that can be easily filtered off, dried, and ground
to particle sizes desired for pharmaceutical formulations. These
properties make polymorph B particularly suitable for
pharmaceutical application.
[0074] In one embodiment, a composition comprising polymorph B of
BH4 dihydrochloride is a very stable crystalline form that can be
ground into a powder for pharmaceutical formulations. This powder
form can then be blended to make polymorph B particularly suitable
for dry blending with excipients for pharmaceutical
application.
Stable Capsule Dosage Forms
[0075] The capsule dosage forms described herein contain BH4
dihydrochloride that exhibits unexpectedly stability. Commonly,
unstable hygroscopic pharmaceuticals or pharmaceuticals unstable in
the presence of water absorb water from the capsule walls and
degrade in capsules. Without intending to be bound by any
particular theory, one possible explanation for the degradation
(and consequent loss of efficacy) of such pharmaceuticals is that
hygroscopic pharmaceuticals placed in a capsule may cause the
capsule to become brittle and fracture as the water present in the
capsule shell is desorbed or leached from the capsule shell into
the filled pharmaceutical material. Typical hard gelatin capsule
shells have around 10 wt. % moisture content, and typical HPMC
capsules have about 4 to 6 wt. % moisture content.
[0076] Capsule dosage forms, which comprise BH4 dihydrochloride and
which are stable at room temperature or warmer for a long period of
time without the capsule becoming brittle and prone to fracturing
and without the BH4 dihydrochloride degrading, have been developed
and are disclosed herein. In controlled studies, the BH4
dihydrochloride in the capsules provided herein unexpectedly
displayed greater stability under accelerated stability testing
conditions than BH4 dihydrochloride contained in previously
disclosed tablet dosage forms. In certain embodiments, greater than
about 95%, greater than about 96%, greater than about 97%, greater
than about 98%, greater than about 99%, greater than about 99.1%,
greater than about 99.2%, greater than about 99.3%, greater than
about 99.4%, or greater than about 99.5% of the BH4 dihydrochloride
remains after a capsule filled with a formulation comprising BH4
dihydrochloride is stored in a heat induction-sealed container at
40.degree. C. and 75% relative humidity for six months. In further
embodiments, greater than about 80%, greater than about 81%,
greater than about 82%, greater than about 83%, greater than about
84%, greater than about 85%, greater than about 86%, greater than
about 87%, greater than about 88%, greater than about 89%, greater
than about 90%, greater than about 91%, greater than about 92%,
greater than about 93%, greater than about 94%, or greater than
about 95% of the BH4 dihydrochloride from such capsules dissolve
within 30 minutes according to U.S.P. Method II at 50 r.p.m. in 0.1
N hydrochloric acid maintained at 37.degree. C. Furthermore, the
BH4 or BH4-related compound within the capsule remains stable when
stored without desiccant.
[0077] In an embodiment, the shell of capsules comprising BH4 or a
BH4-related compound can comprise one or more natural, modified, or
synthetic saccharides or polysaccharides. In one embodiment, the
capsule shell is made of or contains one or more derivatives of
cellulose in which cellulose has been modified physically or
chemically. In a specific embodiment, the cellulose derivative is
hydroxypropyl methylcellulose (HPMC), also called "hypromellose".
In another embodiment, the capsule shell is made of or contains one
or more members of the carrageenan family of polysaccharides. In
yet another embodiment, the capsule shell is made of or contains
one or more starch derivatives in which starches have been modified
physically or chemically.
[0078] In a further embodiment, the shell of capsules does not
contain a saccharide or a polysaccharide. In a particular
embodiment, the capsule shell is made of or contains gelatin. In
one embodiment, the gelatin capsule is hard gelatin capsule. In
another embodiment, the gelatin capsule is not soft gelatin
capsule. In a further embodiment, the capsule shell is made of or
contains gelatin and polyethylene glycol (PEG). In certain
embodiments, the capsule shell is made of or contains gelatin and
PEG 4000.
[0079] In another embodiment of non-polysaccharide capsules, the
capsule shell is made of or contains one or more synthetic
polymers. In one embodiment, the synthetic polymers are selected
from homopolymers and copolymers formed from polyvinyl alcohol,
acrylic acid, or methyl methacrylate, or combinations thereof.
[0080] The shell of capsules can also be made of or contain one or
more natural materials. In certain embodiments, the natural
material is acacia.
[0081] When pullulan capsules, hard gelatin capsules, and HPMC
capsules comprising the same BH4-containing formulation were stored
under the same conditions, the pullulan capsule shells softened and
collapsed within one month, unlike the other two kinds of capsules.
Accordingly, in one embodiment, the shell of capsules comprising
BH4 or a BH4-related compound is essentially free of pullulan. As
used herein, a "pullulan-free" capsule or a capsule "essentially
free of pullulan" is a capsule having a shell that contains no
pullulan or an amount of pullulan such that the stability of the
capsule shell is not adversely affected by the pullulan content. In
a specific embodiment, the shell of the capsule does not contain
pullulan. In other embodiments where the capsule shell can contain
pullulan, the capsule shell can contain no more than about 90%, no
more than about 85%, no more than about 75%, no more than about
65%, no more than about 55%, no more than about 45%, no more than
about 35%, no more than about 25%, no more than about 15%, no more
than about 10%, no more than about 5%, no more than about 3%, no
more than about 2%, no more than about 1%, no more than about 0.5%,
or no more than about 0.1% pullulan by weight.
[0082] In an embodiment, the stable capsule dosage forms comprise a
pharmaceutical formulation comprising a stable crystalline form of
BH4 or a BH4-related compound, and one or more pharmaceutically
acceptable excipients, diluents, or carriers. The capsule dosage
forms optionally can further comprise one or more other therapeutic
agents useful for the condition or disorder to be treated.
[0083] Because BH4 is more unstable in the presence of moisture, it
is advantageous to reduce or prevent the exposure of BH4 to
moisture. Accordingly, in one embodiment, the excipient(s) in the
pharmaceutical formulation are anhydrous. In another embodiment,
the excipient(s) are not hygroscopic. In still another embodiment,
the formulation contains one or more excipients that absorb and
sequester moisture.
[0084] Excipients are well known for the various kinds of
pharmaceutical formulation known in the art and include, without
limitation, binders (including natural and synthetic polymers),
fillers, diluents, lubricants, glidants, surfactants,
disintegration agents, sweetening agents, flavoring agents,
coloring agents, coating materials, preservatives, dyes,
thickeners, adjuvants, antimicrobial agents, antioxidants, and
carriers for the various kinds of formulation. In an embodiment,
the pharmaceutical formulation in the capsule dosage forms
comprises BH4 or a BH4-related compound and one or more
pharmaceutically acceptable excipients selected from binders,
fillers, diluents, disintegration agents, glidants, antioxidants
(including acidic antioxidants), lubricants, surfactants,
adjuvants, sweetening agents, flavoring agents, coloring agents,
and combinations thereof. In one embodiment, the formulation
contains a binder, filler or diluent, and a disintegration agent.
In another embodiment, the formulation further contains an acidic
antioxidant. In yet another embodiment, the formulation further
contains a lubricant.
[0085] Nonlimiting examples of binders useful in compositions
described herein include natural and synthetic gums (e.g., acacia,
gum tragacanth, guar gum); starches and derivatives thereof (e.g.,
corn starch, potato starch, pre-gelatinized starch); gelatin;
alginic acid and alginates (e.g., sodium alginate); celluloses and
derivatives thereof (e.g., microcrystalline cellulose, methyl
cellulose, ethyl cellulose, hydroxypropyl methyl cellulose,
cellulose acetate, carboxymethyl cellulose calcium, sodium
carboxymethyl cellulose); biodegradable polymers, such as homo- and
co-polyesters of dicarboxylic acids, alkylene glycols, polyalkylene
glycols and/or aliphatic hydroxyl carboxylic acids; homo- and
co-polyamides of dicarboxylic acids, alkylene diamines, and/or
aliphatic amino carboxylic acids; corresponding
polyester-polyamide-co-polymers, polyanhydrides, polyorthoesters,
polyphosphazene, and polycarbonates. The biologically degradable
polymers can be linear, branched, or crosslinked. Specific examples
are poly-glycolic acid, poly-lactic acid, and
poly-d,l-lactide/glycolide. Other non-limiting examples of polymers
are water-soluble polymers, such as polyoxaalkylenes,
polyoxaethylene, polyoxapropylene and mixed polymers thereof,
poly-acrylamides and hydroxylalkylated polyacrylamides, poly-maleic
acid and esters or amides thereof, poly-acrylic acid and esters or
amides thereof, poly-vinylalcohol and esters or ethers thereof,
poly-vinylimidazole, poly-vinylpyrrolidone, and natural polymers,
such as chitosan.
[0086] Non-limiting examples of fillers and diluents include talc,
calcium carbonate (e.g., granules or powder), calcium phosphate,
celluloses and derivatives thereof (e.g., microcrystalline
cellulose, powdered cellulose), dextrates, kaolin, mannitol,
silicic acid, sorbitol, and starches and derivatives thereof (e.g.,
starch, pre-gelatinized starch).
[0087] Disintegration agents are believed to assist in rapid
disintegration of solid pharmaceuticals by absorbing water and
expanding. Non-limiting examples of disintegration agents include
gums, agar, algins, alginic acid, clays, calcium carbonate,
polacrilin potassium, polyvinylpyrrolidone (also called povidone),
crospovidone (cross-linked povidone), celluloses and derivatives
thereof (e.g., microcrystalline cellulose, croscarmellose sodium,
cross-linked sodium carboxymethylcellulose (NaCMC, e.g., sold under
the name AC-DI-SOL)), and starches and derivatives thereof (e.g.,
sodium starch glycolate, corn starch, potato starch, tapioca
starch, pre-gelatinized starch). Pharmaceuticals formulated with
crospovidone can exhibit more rapid disintegration than
pharmaceuticals formulated with povidone.
[0088] Antioxidants can be included in the inventive compositions
and can help stabilize tetrahydrobiopterin, especially after
dissolution. Low pH aqueous solutions of BH4 are more stable than
BH4 solutions of high pH. Exemplary acidic antioxidants include
alpha-lipoic acid, ascorbic acid (including L-ascorbic acid, also
called vitamin C), fatty acid esters of ascorbic acid such as
ascorbyl palmitate and ascorbyl stearate, and salts of ascorbic
acid such as sodium, calcium, and potassium ascorbate. Non-acidic
antioxidants can also be used in the dosage forms. Nonlimiting
examples of non-acidic antioxidants include vitamin A (including
beta-carotene and retinol), vitamin E (including alpha-tocopherol),
ebselen, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy (TEMPOL), and
superoxide dismutase. Acidic additives, e.g., citric acid and malic
acid, can be added to enhance stability of the dosage forms.
[0089] The amount of ascorbic acid in the dosage forms described
herein can vary depending on the condition to be treated. In one
embodiment, the pharmaceutical formulation in the capsule dosage
forms comprises ascorbic acid in a weight ratio of ascorbic acid to
BH4 of about 1:2, 1:1.5, 1:1, 1.5:1 or 2:1. In another embodiment,
the ascorbic acid to BH4 weight ratio in the formulation is no more
than about 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11,
1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20. In a
particular embodiment, the ascorbic acid to BH4 weight ratio is
about 1:10 or less.
[0090] Nonlimiting examples of lubricants useful in compositions
described herein include natural and synthetic oils, fats, waxes,
fatty acids, and salts of fatty acids. Lubricants can improve
processability and content uniformity of the pharmaceutical.
Non-limiting examples of lubricants include mineral oil, light
mineral oil, glycerin, sorbitol, mannitol, glycols (e.g.,
polyethylene glycol), hydrogenated vegetable oil (e.g., peanut oil,
cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil,
soybean oil), talc, sodium lauryl sulfate, ethyl oleate, ethyl
laureate, agar, various forms of silicon dioxide (e.g., syloid
silica gel, coagulated aerosol of silica), stearyl fumaric acid and
salt forms of stearyl fumarate (e.g., sodium stearyl fumarate), and
stearic acid and salt forms of stearate (e.g., magnesium stearate,
calcium stearate, zinc stearate).
[0091] Surfactants useful in compositions described herein can be
anionic, cationic, amphoteric, or neutral. Nonlimiting examples of
surfactants useful in compositions described herein include
lecithin; phospholipids; alkyl sulfates, such as octyl sulfate,
decyl sulfate, dodecyl sulfate, tetradecyl sulfate, hexadecyl
sulfate, and octadecyl sulfate; 1-acylaminoethane-2-sulfonic acids,
such as 1-octanoylaminoethane-2-sulfonic acid,
1-decanoylaminoethane-2-sulfonic acid,
1-dodecanoylaminoethane-2-sulfonic acid,
1-tetradecanoylaminoethane-2-sulfonic acid,
1-hexadecanoylaminoethane-2-sulfonic acid, and
1-octadecanoylaminoethane-2-sulfonic acid; taurocholic acid and
taurodeoxycholic acid; bile acids and salts thereof, such as cholic
acid, deoxycholic acid and sodium glycocholates; sodium caprate,
sodium laurate, sodium oleate, sodium lauryl sulfate, sodium cetyl
sulphate, sulfated castor oil, and sodium dioctylsulfosuccinate;
cocamidopropylbetaine and laurylbetaine; fatty alcohols;
cholesterols; glycerol mono- or -distearate, glycerol mono- or
-dioleate, and glycerol mono- or -dipalmitate; and polyoxyethylene
stearate.
[0092] Examples of sweetening agents include, without limitation,
sucralose, sucrose, fructose, lactose, saccharin, sodium
saccharide, and the like. Non-limiting examples of flavoring agents
include peppermint, oil of wintergreen, orange flavoring, cherry
flavoring, and the like. Examples of coloring agents include, but
are not limited to, riboflavin, cochineal dye, carmine, blue No. 1
for food use, yellow No. 4 aluminum lake for food use, yellow No. 5
aluminum lake for food use, red No. 3 aluminum lake for food use,
red No. 106 for food use, iron sesquioxide, yellow iron
sesquioxide, and the like.
[0093] The pharmaceutical formulation in the stable capsule dosage
forms described herein optionally can also comprise other
excipients, such as mannitol, hydroxyl propyl cellulose,
microcrystalline cellulose, and non-reducing sugars, such as
xylitol, sorbitol, trehalose, melezitose, planteose, and raffinose.
Without intending to be bound by any particular theory, reducing
sugars may react with BH4 under certain conditions. Other
excipients useful in compositions described herein include
phosphates, such as dicalcium phosphate.
[0094] The pharmaceutical formulation in the stable capsule dosage
forms can optionally include one or more other therapeutic agents
suitable for the condition to be treated. In one embodiment, the
other therapeutic agents are selected from folates, including, but
not limited to, folate precursors, folic acids and folate
derivatives, e.g., folinic acid (leucovorin); vitamins, such as
vitamin C (ascorbic acid), vitamin B2 (riboflavin), and vitamin
B12; neurotransmitter precursors, such as L-dopa, carbidopa, and
serotonin; 5-hydroxytryptophan; arginine; and combinations
thereof.
[0095] Exemplary folates, including folate precursors, folic acids,
and folate derivatives, are disclosed in U.S. Pat. Nos. 6,011,040
and 6,544,994 (each of which is incorporated herein by reference in
its entirety), and include folic acid (pteroylmonoglutamate),
dihydrofolic acid, tetrahydrofolic acid, 5-methyltetrahydrofolic
acid, 5,10-methylenetetrahydrofolic acid,
5,10-methenyltetrahydrofolic acid, 5,10-formiminotetrahy drofolic
acid, 5 -formyltetrahydrofolic acid (leucovorin),
10-formyltetrahydrofolic acid, 10-methyltetrahydrofolic acid, one
or more of the folylpolyglutamates, compounds in which the pyrazine
ring of the pterin moiety of folic acid or of the
folylpolyglutamates is reduced to give dihydrofolates or
tetrahydrofolates, derivatives of all the preceding compounds in
which the N-5 or N-10 position carries one carbon unit at various
levels of oxidation, pharmaceutically acceptable salts thereof, and
combinations of two or more thereof. Exemplary tetrahydrofolates
include 5-formyl-(6S)-tetrahydrofolic acid,
5-methyl-(6S)-tetrahydrofolic acid,
5,10-methylene-(6R)-tetrahydrofolic acid,
5,10-methynyl-(6R)-tetrahydrofolic acid,
10-formyl-(6R)-tetrahydrofolic acid, 5
-formimino-(6S)-tetrahydrofolic acid, or (6S)-tetrahydrofolic acid,
and pharmaceutically acceptable salts thereof. Exemplary salts
include sodium, potassium, calcium, and ammonium salts. Exemplary
relative weight ratios of BH4 to folates to arginine can be in a
range from about 1:10:10 to about 10:1:1.
[0096] In a specific embodiment, the BH4 used in compositions
described herein is formulated as a dihydrochloride salt. Other
salt forms of BH4 possessing the desired physicochemical properties
and biological activity can also be used. For example, BH4 salts
with inorganic or organic acids are within the scope of the present
disclosure. Nonlimiting examples of alternative BH4 salt forms
include BH4 salts of acetic acid, citric acid, oxalic acid,
tartaric acid, fumaric acid, and mandelic acid. Carbonates or
hydrogen carbonates are also possible.
[0097] Pharmaceutically acceptable salts can be formed with metals
or amines, such as alkali and alkaline earth metals or organic
amines. Pharmaceutically acceptable salts of compounds can also be
prepared with a pharmaceutically acceptable cation. Suitable
pharmaceutically acceptable cations are well known to those skilled
in the art and include alkaline, alkaline earth, ammonium, and
quaternary ammonium cations. Non-limiting examples of metals used
as cations are sodium, potassium, magnesium, ammonium, calcium,
ferric, and the like. Non-limiting examples of suitable amines
include isopropylamine, trimethylamine, histidine,
N,N'-dibenzylethylenediamine, chloroprocaine, choline,
diethanolamine, dicyclohexylamine, ethylenediamine,
N-methylglucamine, and procaine.
[0098] Pharmaceutically acceptable salts include inorganic and
organic acid salts. Non-limiting examples of suitable salts include
hydrochlorides, acetates, citrates, salicylates, nitrates, and
phosphates. Other suitable pharmaceutically acceptable salts are
well known to those skilled in the art and include those formed
with, e.g., acetic, citric, oxalic, tartaric or mandelic acid,
hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid or
phosphoric acid; with organic carboxylic, sulfonic, sulfo- or
phosphor-acids or N-substituted sulfamic acids, for example, acetic
acid, phenylacetic acid, propionic acid, glycolic acid, succinic
acid, maleic acid, hydroxymaleic acid, methylmaleic acid, fumaric
acid, malic acid, tartaric acid, lactic acid, oxalic acid, gluconic
acid, glucaric acid, glucuronic acid, citric acid, benzoic acid,
cinnamic acid, mandelic acid, salicylic acid, 4-aminosalicylic
acid, 2-phenoxybenzoic acid, 2-acetoxybenzoic acid, embonic acid,
nicotinic acid, isonicotinic acid, methanesulfonic acid,
ethanesulfonic acid, 2-hydroxyethanesulfonic acid, ethane
1,2-disulfonic acid, benzenesulfonic acid, 4-methylbenzenesulfonic
acid, 2-naphthalenesulfonic acid, naphthalene-1,5-disulfonic acid,
2- or 3-phosphoglycerate, glucose-6-phosphate, or
N-cyclohexylsulfamic acid (with the formation of cyclamates); with
other acid organic compounds, such as ascorbic acid; or with amino
acids, such as the 20 alpha amino acids involved in the synthesis
of proteins in nature, e.g., glutamic acid or aspartic acid.
[0099] In one embodiment, the pharmaceutical formulation in the
stable capsule dosage forms comprises BH4 or a BH4-related
compound, crospovidone, and stearyl fumaric acid or a salt form of
stearyl fumarate. In an embodiment, the salt form of stearyl
fumarate contains an alkali metal salt, such as lithium, sodium,
potassium, and cesium. In a specific embodiment, the salt form of
stearyl fumarate is sodium stearyl fumarate.
[0100] In an embodiment, the pharmaceutical formulation in the
stable capsule dosage forms comprises an initial amount of BH4 or a
BH4-related compound (e.g., (6R)-L-erythro-BH4 dihydrochloride) in
a range from about 30% to about 70%, crospovidone from about 2% to
about 10%, and stearyl fumaric acid or a salt form of stearyl
fumarate (e.g., sodium stearyl fumarate) from about 0.5% to about
5%, by weight of the formulation. In narrower embodiments, the
formulation comprises: (1) BH4 or a BH4-related compound from about
35% to about 65%, or from about 30% to about 60%, or from about 35%
to about 60%, or from about 35% to about 55%, or from about 40% to
about 60%, or from about 45% to about 55%; (2) crospovidone from
about 2% to about 8%, or from about 3% to about 7%, or from about
3% to about 6%, or from about 4% to about 5%; and (3) stearyl
fumaric acid or a salt form of stearyl fumarate from about 1% to
about 4%, or from about 1% to about 3%, by weight of the
formulation.
[0101] In another embodiment, the pharmaceutical formulation in the
stable capsule dosage forms further comprises an initial amount of
ascorbic acid in a range from about 0% to about 50%, silicon
dioxide (e.g., colloidal silicon dioxide) from about 0% to about
5%, and mannitol from about 0% to about 50% by weight of the
formulation. In narrower embodiments, the formulation further
comprises: (1) ascorbic acid from about 0.5% to about 40%, or from
about 1% to about 30%, or from about 1% to about 20%, or from about
1% to about 10%, or from about 0.5% to about 5%; (2) silicon
dioxide from about 0.2% to about 4%, or from about 0.2% to about
3%, or from about 0.2% to about 2%; and (3) mannitol from about 5%
to about 50%, or from about 20% to about 50%, or from about 30% to
about 50%, or from about 25% to about 45%, or from about 10% to
about 40%, or from about 20% to about 40%, or from about 15% to
about 35%, by weight of the formulation.
[0102] In yet another embodiment, the pharmaceutical formulation in
the stable capsule dosage forms additionally comprises an initial
amount of 5-hydroxytryptophan (5-HTP) in a range from about 0% to
about 50% by weight of the formulation. In narrower embodiments,
the formulation additionally comprises 5-HTP from about 5% to about
45%, or from about 10% to about 40%, or from about 20% to about
40%, or from about 15% to about 35%, or from about 20% to about
30%, by weight of the formulation.
[0103] In certain embodiments, the stable capsule dosage forms
described herein contain an initial amount of BH4 or a BH4-related
compound (e.g., (6R)-L-erythro-BH4 dihydrochloride) in a range from
about 100 mg to about 500 mg per capsule, or from about 300 mg to
about 500 mg per capsule, or from about 200 mg to about 400 mg per
capsule, or from about 100 mg to about 300 mg per capsule. In
specific embodiments, the stable capsule dosage forms contain an
initial amount of BH4 or a BH4-related compound of about 100 mg per
capsule, or about 150 mg per capsule, or about 160 mg per capsule,
or about 200 mg per capsule, or about 250 mg per capsule, or about
300 mg per capsule, or about 350 mg per capsule, or about 400 mg
per capsule, or about 450 mg per capsule, or about 500 mg per
capsule. It will be apparent to one skilled in the art that the
desired dosage for the treatment, amelioration or prevention of a
BH4-responsive disorder can affect the amount of BH4 or a
BH4-related compound in the capsule dosage forms.
[0104] In one embodiment, provided herein are capsule dosage forms
that contain relatively large amounts of BH4 (e.g.,
(6R)-L-erythro-BH4 dihydrochloride). A non-limiting example of such
a dosage form includes 400 mg of BH4, optionally with a compaction
agent, e.g., microcrystalline cellulose. Potential advantages of
relatively large amounts of BH4 available in a dosage form include
ease of providing the therapeutic, ease of oral administration, and
patient compliance.
[0105] In an embodiment, the stable capsule dosage forms described
herein are useful for treating BH4 deficiency or a condition or
disorder associated with BH4 deficiency (e.g.,
hyperphenylalaninemia due to BH4 deficiency). In one embodiment,
the stable capsule dosage forms useful for treating BH4 deficiency
or a condition associated therewith comprise initial amounts of (1)
BH4 or a BH4-related compound (e.g., (6R)-L-erythro-BH4
dihydrochloride) from about 30% to about 60%, or from about 40% to
about 60%; (2) mannitol from about 20% to about 50%, or from about
30% to about 50%; (3) crospovidone from about 2% to about 8%, or
from about 3% to about 6%; (4) stearyl fumaric acid or a salt form
of stearyl fumarate (e.g., sodium stearyl fumarate) from about 1%
to about 4%, or from about 1% to about 3%; (5) ascorbic acid from
about 1% to about 20%, or from about 1% to about 10%; and (6)
silicon dioxide (e.g., colloidal silicon dioxide) from about 0.2%
to about 4%, or from about 0.2% to about 2%, by weight of the
formulation. In a related embodiment, the stable capsules useful
for treating BH4 deficiency or a condition associated therewith
comprise an initial amount of BH4 or a BH4-related compound (e.g.,
(6R)-L-erythro-BH4 dihydrochloride) in a range from about 100 mg to
about 500 mg per capsule, including but not limited to about 100
mg, about 150 mg, about 160 mg, about 200 mg, about 250 mg, about
300 mg, about 350 mg, about 400 mg, about 450 mg, or about 500 mg
per capsule. In a particular embodiment, the shell of the stable
capsules useful for treating BH4 deficiency or a condition
associated therewith is made of or comprises hydroxypropyl
methylcellulose (HPMC). In another embodiment, the shell of such
stable capsules is made of or comprises gelatin.
[0106] In one particular embodiment, the stable capsule dosage form
is useful for reducing blood phenylalanine (Phe) levels in patients
with hyperphenylalaninemia (HPA) due to tetrahydrobiopterin (BH4)
responsive Phenylketonuria (PKU). In another particular embodiment,
the stable capsule dosage is used in conjunction with a
Phe-restricted diet to reduce blood phenylalanine (Phe) levels in
patients with hyperphenylalaninemia (HPA) due to
tetrahydrobiopterin (BH4) responsive Phenylketonuria (PKU).
[0107] In a particular embodiment of a stable capsule dosage form
useful for treating BH4 deficiency or a condition associated with
BH4 deficiency (e.g., hyperphenylalaninemia due to BH4 deficiency),
the pharmaceutical formulation of the dosage form comprises the
following ingredients, in terms of weight % of the formulation and
mg per capsule: (1) 50.0% (6R)-L-erythro-BH4 dihydrochloride (160.0
mg); (2) 38.5% mannitol (123.2 mg); (3) 5.0% ascorbic acid (16.0
mg); (4) 4.0% crospovidone (12.8 mg); (5) 1.75% sodium stearyl
fumarate (5.6 mg); and (6) 0.75% colloidal silicon dioxide (2.4
mg). In one embodiment, the shell of the capsule is made of or
comprises hydroxypropyl methylcellulose. In another embodiment, the
capsule shell is made of or comprises gelatin. In a specific
embodiment, the capsule is size 0 capsule (0.30 inch by 0.85
inch).
[0108] In another particular embodiment of a stable capsule dosage
form useful for treating BH4 deficiency or a condition associated
with BH4 deficiency (e.g., hyperphenylalanemia due to BH4
deficiency), the pharmaceutical formulation of the dosage form
comprises the following ingredients, in terms of weight % of the
formulation and mg per capsule: (1) 50.0% (6R)-L-erythro-BH4
dihydrochloride (200.0 mg); (2) 41.0% mannitol (164.0 mg); (3) 2.5%
ascorbic acid (10.0 mg); (4) 4.0% crospovidone (16.0 mg); (5) 1.75%
sodium stearyl fumarate (7.0 mg); and (6) 0.75% colloidal silicon
dioxide (3.0 mg). In one embodiment, the shell of the capsule is
made of or comprises hydroxypropyl methylcellulose. In another
embodiment, the capsule shell is made of or comprises gelatin. In
an embodiment, the capsule is size 0 (0.30 inch by 0.85 inch) or
size 00 (0.33 inch by 0.92 inch) capsule.
[0109] In a further embodiment, the stable capsule dosage forms
described herein are useful for treating sickle cell disease (SCD),
peripheral arterial disease (PAD), chronic kidney disease (CKD), or
hypertension. In one embodiment, the stable capsule dosage forms
useful for treating SCD, PAD, CKD, or hypertension comprise initial
amounts of (1) BH4 or a BH4-related compound (e.g.,
(6R)-L-erythro-BH4 dihydrochloride) from about 30% to about 60%, or
from about 40% to about 60%, or from about 40% to about 50%; (2)
ascorbic acid from about 30% to about 60%, or from about 40% to
about 60%, or from about 40% to about 50%; (3) crospovidone from
about 2% to about 8%, or from about 3% to about 6%; (4) stearyl
fumaric acid or a salt form of stearyl fumarate (e.g., sodium
stearyl fumarate) from about 1% to about 4%, or from about 1% to
about 3%; (5) silicon dioxide (e.g., colloidal silicon dioxide)
from about 0.2% to about 4%, or from about 0.2% to about 2%; and
(6) 5-methyltetrahydrofolate (5-MTHF) or a salt form thereof from
about 0% to about 2%, or from about 0.01% to about 1%, or from
about 0.01% to about 0.5%, by weight of the formulation. The 5-MTHF
can be a pharmaceutically acceptable salt of 5-MTHF, e.g., the
calcium salt of 5-MTHF. In a related embodiment, the stable
capsules useful for treating SCD, PAD, CKD, or hypertension
comprise initial amounts of BH4 or a BH4-related compound (e.g.,
(6R)-L-erythro-BH4 dihydrochloride) and ascorbic acid in a weight
ratio of about 10:1, about 9:1, about 8:1, about 7:1, about 6:1,
about 5:1, about 4:1, about 3:1, about 2.5:1, about 2:1, about
1.5:1, about 1:1, about 1:1.5, or about 1:2. In another related
embodiment, the stable capsules useful for treating SCD, PAD, CKD,
or hypertension comprise an initial amount of BH4 or a BH4-related
compound (e.g., (6R)-L-erythro-BH4 dihydrochloride) in a range from
about 100 mg to about 500 mg per capsule, including but not limited
to about 100 mg, about 150 mg, about 200 mg, about 250 mg, about
300 mg, about 350 mg, about 400 mg, about 450 mg, or about 500 mg
per capsule. In a particular embodiment, the shell of the stable
capsules useful for treating SCD, PAD, CKD, or hypertension is made
of or comprises hydroxypropyl methylcellulose (HPMC). In another
embodiment, the shell of such stable capsules is made of or
comprises gelatin.
[0110] In a particular embodiment of a stable capsule dosage form
useful for treating SCD, PAD, CKD, or hypertension, the
pharmaceutical formulation of the dosage form comprises the
following ingredients, in terms of weight % of the formulation and
mg per capsule: (1) 46.75% (6R)-L-erythro-BH4 dihydrochloride
(250.0 mg); (2) 46.75% ascorbic acid (250.0 mg); (3) 3.98% or 3.96%
crospovidone (21.3 mg or 21.2 mg); (4) 1.75% sodium stearyl
fumarate (9.4 mg); (5) 0.75% colloidal silicon dioxide (4.0 mg);
and (6) 0.02% or 0.04% 5-methyltetrahydrofolate, calcium salt (0.1
mg or 0.2 mg). In an embodiment, the shell of the capsule is made
of or comprises hydroxypropyl methylcellulose. In another
embodiment, the capsule shell is made of or comprises gelatin. In
yet another embodiment, the capsule is size 00 capsule (0.33 inch
by 0.92 inch).
[0111] In another particular embodiment, the stable capsule dosage
form can be used for treating and ameliorating autism. BH4 has been
shown to be effective in treating autism in humans (see, e.g.,
Fernell et al., Dev. Med. & Child Neurology, 39: 313-318
(1997); Frye et al. Neurotherapeutics, 7: 241-249; Danfors et al.,
J. Clinical Psychopharmacology, 25(5): 485-489). Fernell shows that
children treated with BH4 for 4, 8, and 12 weeks had significant
increases in their total scores on the Parental Satisfaction Survey
("PSS"). Fernell, Table II, page 316. Frye reviews research using
BH4 to treat autism and concludes that BH4 represents a novel
therapy for autism spectrum disorder. Danfors shows that children
treated with BH4 had significant improvement of their social
interaction scores after 6 months of treatment and found a high
positive correlation between response of the social interaction
score and IQ.
[0112] In one embodiment, the BH4 or BH4-related compound can be
used for treating or ameliorating austism in children. In one
embodiment, the BH4 or BH4-related compound can be used for
treating or ameliorating autism in adults. In a particular
embodiment, the BH4 or BH4-related compound can be administered in
conjunction with a second pharmaceutical composition to treat or
ameliorate the symptoms of autism. In a particular embodiment, the
second pharmaceutical compound for the combination treatment can be
selected from groups consisting of stimulants, antidepressants,
antianxiety medications, non-stimulant ADHD medications,
antipsychotics, mood stabilizers, or Alzheimer's medications.
[0113] In a particular embodiment, the BH4 or BH4-related compound
useful for treating and ameliorating autism is BH4 dihydrochloride.
In a particular embodiment, BH4 dihydrochloride can be administered
to children suffering from autism. In particular embodiment, the
child is about 0-18 years old, 1-18 years old, about 2-18 years
old, about 3-18 years old, about 3-17 years old, about 3-16 years
old, about 3-15 years old, about 3-14 years old, about 3-13 years
old, about 3-12 years old, about 3-11 years old, about 3-10 years
old, about 3-9 years old, about 3-8 years old, about 3-7 years old,
or about 3-6 years old. In a particular embodiment, the is
administered to a subject during childhood and adulthood. In a
particular embodiment, the formulation can be administered at a
dosage of about 5-50 mg/kg/day. In a particular embodiment, the
formulation can be administered at a dosage of about 5 mg/kg/day,
or about 7.5 mg/kg/day, or about 10 mg/kg/day, or about 10.5
mg/kg/day, or about 11 mg/kg/day, or about 11.5 mg/kg/day, or about
12 mg/kg/day, or about 12.5 mg/kg/day, or about 13 mg/kg/day, or
about 13.5 mg/kg/day, or about 14 mg/kg/day, or about 14.5
mg/kg/day, or about 15 mg/kg/day, or about 15.5 mg/kg/day, or about
16 mg/kg/day, or about 16.5 mg/kg/day, or about 17 mg/kg/day, or
about 17.5 mg/kg/day, or about 18 mg/kg/day, or about 18.5
mg/kg/day, or about 19 mg/kg/day, or about 19.5 mg/kg/day, or about
20 mg/kg/day. In another embodiment, the pharmaceutical formulation
comprising BH4 or a BH4-related compound can be used to treat or
ameliorate autism at a dosage of 25 mg/kg/day or more.
[0114] In a particular embodiment, the stimulants administered in
conjunction with the BH4 or BH4-related compound to treat and
ameliorate autism may include but are not limited to amphetamines,
methylphenidate, pemoline, dextroamphetamines, dexmethylphenidate,
methylphenidate, and combinations thereof. The non-stimulant
administered in conjunction with the BH4 or BH4-related compound to
treat and ameliorate autism may include but is not limited to
atomoxetine. The antidepressants and anti-anxiety medications
administered in conjunction with the BH4 or BH4-related compound to
treat and ameliorate autism may include, but are not limited to
clomipramin, buspirone, buspirone, fluvoxamine, paroxetine,
fluoxetine, nefazodone, doxepin, imipramine, bupropion, sertraline,
and combinations thereof. The mood stabilizing medications
administered in conjunction with the BH4 or BH4-related compound to
treat and ameliorate autism may include but are not limited to
lithium citrate, valproic acid, lithium carbonate, carbamazepine,
and combinations thereof. The Alzheimer's medication administered
in conjunction with the BH4 or BH4-related compound to treat and
ameliorate autism may include but is not limited to memantine
HCl.
[0115] Capsule dosage forms can be manufactured by admixing the
pharmaceutical components, optionally finely dividing them, and
filling capsules. An additional method for manufacturing capsule
dosage forms can include compounding tetrahydrobiopterin with an
excipient, e.g., a pharmaceutically acceptable carrier. Further, a
capsule can then be filled with the compounded material and,
optionally, the capsule can be stored in a sealed container, e.g.,
a heat induction-sealed polyethylene container. The compounded
pharmaceutical components or powder blends can be uniformly filled
into capsules using an automated capsule-filling equipment or can
be manually filled into capsules, as is known in the art. It is
understood that the "initial amount" of a pharmaceutical component
(e.g., BH4, a BH4-related compound, 5-hydroxytryptophan, or an
excipient) in a capsule is that amount of the component which is
filled into the capsule in the process for producing the capsule
dosage form.
[0116] In an embodiment, the stable capsule dosage forms, including
the pharmaceutical formulations contained therein, are made by a
process that does not include adding liquid water. The dry capsule
manufacturing process comprises a dry process of mixing and
blending an initial amount of the active ingredient, BH4 or a
BH4-related compound (e.g., (6R)-L-erythro-BH4 dihydrochloride),
with an initial amount of an excipient that optionally has been
screened with an appropriate mesh screen, optionally mixing and
blending the resulting ingredients with an initial amount of a
second excipient that optionally has been screened, optionally
doing the same with additional excipients, and filling the
resulting dry blend of ingredients into capsules.
[0117] In another embodiment, the methods involve the step of
informing the patient that absorption of tetrahydrobiopterin is
increased when it is ingested with food compared to when ingested
without food. In some embodiments, the patient is informed that
ingestion shortly following a meal, for example, a high-fat,
high-calorie meal, results in an increase in any one, two, three or
all of the following parameters: mean plasma concentration, Cmax,
AUC, AUC(0-t) and/or AUC(inf). In other embodiments, the patient is
informed that administration of BH4 with a high-fat meal increases
Cmax and AUC compared to administration of BH4 without food (in a
fasting condition). In some embodiments, the relative increase can
be at least 20% or 30% or more.
[0118] In another embodiment, such methods involve administering
BH4, whether swallowed as a solid or semisolid dosage form, or
dissolved in a liquid, with food, e.g., a high-fat food or a
high-fat and/or high-calorie meal. In another embodiment, BH4,
whether swallowed or dissolved, is administered at a specified time
including but not limited to morning, day, night, same time of the
day, with food, e.g., a high-fat food or a high-fat and/or
high-calorie meal, one or more times a day. In another embodiment,
BH4 is ingested once daily as a solid dosage form just after meals.
In another embodiment the solid dosage form is a formulated tablet
or capsule. In other embodiments, BH4 is ingested within
approximately 0 to 30 minutes, or 5 to 20 minutes, of eating a
meal.
[0119] The BH4 and the food may be ingested at approximately the
same time, or the BH4 may be ingested before or after the food. The
period of time between consuming the food and taking BH4, either
swallowed or dissolved, may be at least 5 minutes. For example, BH4
may be administered 60 minutes, 30 minutes, 25 minutes, 20 minutes,
15 minutes, 10 minutes, or 5 minutes before or after a meal.
[0120] In another embodiment, to maximize oral bioavailability of
BH4 at each administration, BH4 should be taken with food, e.g., a
high fat food or a high fat and/or high calorie meal.
Alternatively, to maximize consistency of oral bioavailability
between administrations, BH4 should be taken on an empty stomach
(e.g., 1 hour before or 2 hours after a meal).
[0121] The container or packaging containing BH4 capsule dosage
forms is selected, inter alfa, to minimize or prevent moisture
penetration into and contamination of the formulation in the dosage
form and thereby enhance the stability of the formulation. In an
embodiment, BH4 capsule dosage forms are disposed in a sealed
container or packaging. Examples of sealed containers include
polyethylene bottles, e.g., high density polyethylene bottles
closed with a heat-induction seal. Additional non-limiting examples
of sealed containers or packaging include glass bottles, tubes,
hermetically sealed foil packaging, thermally sealed polyethylene
bags, laminated foil pouches, and blister packs. In one embodiment,
a desiccant is disposed in the container or packaging containing
the BH4 capsule dosage forms, or is incorporated in the closure,
stopper, or cap of the container or packaging. In another
embodiment, no desiccant is disposed in the container or packaging
containing the BH4 capsule dosage forms, or is incorporated in the
closure, stopper, or cap of the container or packaging.
[0122] In another embodiment, at least about 90% of the initial
amount of the BH4 or BH4-related compound remains, after the stable
capsule dosage form is stored at about 40.degree. C. and about 75%
RH for a period of about three months. In another embodiment, at
least about 91%, or at least about 92%, or at least about 93%, or
at least about 94%, or at least about 95%, or at least about 96%,
or at least about 97%, or at least about 98%, or at least about 99%
of the initial amount of BH4 or BH4-related compound remains after
the stable capsule dosage form is stored at about 40.degree. C. and
about 75% RH for a period of about three months.
[0123] In another embodiment, at least about 85% of the initial
amount of the BH4 or BH4-related compound dissolves within about 15
minutes, after the stable capsule dosage form is stored at about
40.degree. C. and about 75% RH for a period of about three months.
In another embodiment, at least about 86%, or at least 87%, or at
least 88%, or at least 89%, or at least 90%, or at least 91%, or at
least 92%, or at least 93%, or at least 94%, or at least 95%, or at
least 96%, or at least 97%, or at least 98%, or at least 99% of the
initial amount of the BH4 or BH4-related compound dissolves within
about 15 minutes, after the stable capsule dosage form is stored at
about 40.degree. C. and about 75% RH for a period of about three
months.
[0124] In another embodiment, at least about 90%, or at least about
91%, or at least about 92%, or at least about 93%, or at least
about 94%, or at least about 95%, or at least about 96%, or at
least about 97%, or at least about 98%, or at least about 99% of
the initial amount of the BH4 or BH4-related compound remains and
at least about 85%, or at least about 86%, or at least 87%, or at
least 88%, or at least 89%, or at least 90%, or at least 91%, or at
least 92%, or at least 93%, or at least 94%, or at least 95%, or at
least 96%, or at least 97%, or at least 98%, or at least 99% of the
initial amount of the BH4 or BH4-related compound dissolves within
about 15 minutes, after the stable capsule dosage form is stored at
about 40.degree. C. and about 75% RH for a period of about three
months.
Stable Sachet Dosage Forms
[0125] The sachet dosage forms described herein contain BH4
dihydrochloride that exhibits unexpected physical stability.
Commonly, granular forms of BH4 dihydrochloride are made by a wet
granulation process (Sugita et al., Patent Publication No.
US2008/0207624 A1). The wet granulation process consists of mixing
the active ingredients with the excipients, adding a liquid binder
to the powder blend and mixing thoroughly, and then screening the
damp mass through a mesh to form granules. Wet granulation is often
preferable because a uniform and better-flowing mixture can be
easily achieved.
[0126] In contrast to wet blending, the dry blend process disclosed
herein does not require the addition of a liquid binder. Instead,
the different components of the mixture are added to a blender
generating a powder through the blending process. Thereafter the
mixture can be screened through a sieve and blended again to
achieve homogeneity. However, not all mixtures are compatible with
the dry blending process because in order for the dry blend to form
a homogonous mixture the components must exhibit compatible
abilities to flow (i.e., flowability).
[0127] Flowability refers to how a given material will flow in a
given piece of equipment. It is dependent on the multidimensional
characteristics of the material (e.g., powder) that are not
inherent. It results from a combination of the powder's physical
properties (i.e., density, cohesive strength, and wall friction)
and the equipment used for handling, storing, or processing the
powder. For example, powders with identical physical properties may
flow differently through a hopper. Furthermore, flowability is a
factor influenced by blending in which the quality of the resulting
blend depends on the type of blender used and on the complex flow
behavior of the powder during the blending cycle. This is because
blending is accomplished by shear, convection, and diffusion and
each factor is dependent on the physical properties of the
material. Accordingly, the flow properties of a blend of materials
cannot be determined based on the flow properties of the individual
components of the blend (e.g., the flowability of small particle
mannitol is different from large particle mannitol and the flow of
a BH4 dihydrochloride-mannitol blend is different and not
predictable based on the flow of the mannitol or BH4 alone).
[0128] Furthermore, the amount of compound used for dry blending
also affects the flowability of the compound and mixtures thereof.
Accordingly, in addition to selecting compounds that have
compatible flow characteristics when combined in a mixture, it is
also necessary to determine the correct concentration of BH4
dihydrochloride to include in the dry blend powder to achieve
acceptable flowability and maintain a homogenous mixture. Thus, in
order to use a dry blending process for BH4 dihydrochloride, the
final mixture must remain homogenous and that can only be achieved
by (1) determining the proper components of the mixture, (2) the
order of addition of components of mixture, and (3) by determining
how the components of the mixture behave in conjunction with one
another. Accordingly, the wet granulation process is commonly used
because flow properties of dry compounds are unpredictable and the
wet granulation process results in the agglomeration of dry powders
into larger and denser granules which flow better and granules
remain homogenous because of the presence of a binder or binders to
prevent segregation of the granules back into its constituent
excipients and active drug substance.
[0129] However, despite the commonality of wet granulation methods,
it is not ideal for all blends. Specifically, BH4 dihydrochloride
is moisture sensitive and will rapidly degrade in the presence of
water. Furthermore, BH4 dihydrochloride is pH sensitive and
commonly degrades in the presence of reducing sugars, flavoring
agents, flavor enhancers, and aqueous solutions and thus wet
blending of BH4 dihydrochloride with excipients can lead to
degradation of the active ingredient. Additionally, BH4
dihydrochloride which is highly soluble in water (>100 mg/mL) is
solubilized during the wet granulation process leading to the loss
of the stable crystalline polymorph B. BH4 dihydrochloride
precipitates as a less stable amorphous form following wet
granulation. Accordingly, the dry blend method of producing a
stable BH4 dihydrochloride powder sachet dosage is ideal.
[0130] In one embodiment, the stable sachet dosage forms comprise a
pharmaceutical formulation comprising a stable crystalline (i.e.,
powder) form of BH4 or a BH4-related compound, and one or more
pharmaceutically acceptable excipients. The sachet dosage forms
optionally can further comprise one or more other therapeutic
agents useful for the condition or disorder to be treated. The
sachet dosage forms can further be in the form of a single chamber
sachet or a dual chamber sachet. The sachet dosage forms can
further contain a stable dry blend BH4 dihydrochloride powder or a
stable BH4 dihydrochloride solution that has been flushed with an
inert gas and hermetically sealed.
[0131] Because BH4 is more unstable in the presence of moisture due
to oxidation, it is advantageous to reduce or prevent the exposure
of BH4 to moisture when the excipient and BH4 dihydrochloride are
combined in the single chamber sachet. Accordingly, in one
embodiment, the excipient(s) in the pharmaceutical formulation are
anhydrous. In another embodiment, the excipient(s) are not
hygroscopic. In another embodiment, the formulation contains one or
more excipients that absorb and sequester moisture. In still
another embodiment, the BH4 dihydrochloride compound is separated
from the excipient(s) that are incompatible with BH4 using a dual
chamber sachet.
[0132] Excipients are well known for the various kinds of
pharmaceutical formulation known in the art and include, without
limitation, binders (including natural and synthetic polymers),
fillers, diluents, glidants, surfactants, sweetening agents,
flavoring agents, coloring agents, coating materials,
preservatives, dyes, thickeners, adjuvants, antimicrobial agents,
antioxidants, and carriers for the various kinds of formulation. In
an embodiment, the pharmaceutical formulation in the sachet dosage
forms comprises BH4 or a BH4-related compound and one or more
pharmaceutically acceptable excipients selected from sweetening
agents, flavoring agents, flavor enhancers, and combinations
thereof.
[0133] Non-limiting examples of fillers and diluents include
maltose, mannitol, xylitol, sorbitol, isomalt, trehalose, and
starches and derivatives thereof (e.g., starch, pre-gelatinized
starch).
[0134] Antioxidants can be included in the inventive compositions
and can help stabilize tetrahydrobiopterin, especially after
dissolution. Low pH aqueous solutions of BH4 are more stable than
BH4 solutions of high pH. Exemplary acidic antioxidants include
alpha-lipoic acid, ascorbic acid (including L-ascorbic acid, also
called vitamin C), fatty acid esters of ascorbic acid such as
ascorbyl palmitate and ascorbyl stearate, and salts of ascorbic
acid such as sodium, calcium, and potassium ascorbate. Non-acidic
antioxidants can also be used in the dosage forms. Nonlimiting
examples of non-acidic antioxidants include vitamin A (including
beta-carotene and retinol), vitamin E (including alpha-tocopherol),
ebselen, 4-hydroxy-2,2,6,6-tetramethylpiperidinyloxy (TEMPOL), and
superoxide dismutase. Acidic additives, e.g., citric acid and malic
acid, can be added to enhance stability of the dosage forms.
[0135] The amount of ascorbic acid in the dosage forms described
herein can vary depending on the condition to be treated. In one
embodiment, the pharmaceutical formulation in the sachet dosage
forms comprises ascorbic acid in a weight ratio of ascorbic acid to
BH4 of about 1:2, 1:1.5, 1:1, 1.5:1 or 2:1. In another embodiment,
the ascorbic acid to BH4 weight ratio in the formulation is no more
than about 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11,
1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20. Ina
particular embodiment, the ascorbic acid to BH4 weight ratio is
about 1:10 or less.
[0136] Nonlimiting examples of lubricants useful in compositions
described herein include natural and synthetic oils, fats, waxes,
fatty acids, and salts of fatty acids. Lubricants can improve
processability and content uniformity of the pharmaceutical.
Non-limiting examples of lubricants include mineral oil, light
mineral oil, glycerin, sorbitol, mannitol, glycols (e.g.,
polyethylene glycol), hydrogenated vegetable oil (e.g., peanut oil,
cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil,
soybean oil), talc, sodium lauryl sulfate, ethyl oleate, ethyl
laureate, agar, various forms of silicon dioxide (e.g., syloid
silica gel, coagulated aerosol of silica), stearyl fumaric acid and
salt forms of stearyl fumarate (e.g., sodium stearyl fumarate), and
stearic acid and salt forms of stearate (e.g., magnesium stearate,
calcium stearate, zinc stearate).
[0137] Surfactants useful in compositions described herein can be
anionic, cationic, amphoteric, or neutral. Nonlimiting examples of
surfactants useful in compositions described herein include
lecithin; phospholipids; alkyl sulfates, such as octyl sulfate,
decyl sulfate, dodecyl sulfate, tetradecyl sulfate, hexadecyl
sulfate, and octadecyl sulfate; 1-acylaminoethane-2-sulfonic acids,
such as 1-octanoylaminoethane-2-sulfonic acid,
1-decanoylaminoethane-2-sulfonic acid,
1-dodecanoylaminoethane-2-sulfonic acid,
1-tetradecanoylaminoethane-2-sulfonic acid,
1-hexadecanoylaminoethane-2-sulfonic acid, and
1-octadecanoylaminoethane-2-sulfonic acid; taurocholic acid and
taurodeoxycholic acid; bile acids and salts thereof, such as cholic
acid, deoxycholic acid and sodium glycocholates; sodium caprate,
sodium laurate, sodium oleate, sodium lauryl sulphate, sodium cetyl
sulphate, sulfated castor oil, and sodium dioctylsulfosuccinate;
cocamidopropylbetaine and laurylbetaine; fatty alcohols;
cholesterols; glycerol mono- or -distearate, glycerol mono- or
-dioleate, and glycerol mono- or -dipalmitate; and polyoxyethylene
stearate.
[0138] Examples of sweetening agents include, without limitation,
acesulfam potassium, isomalt, Magna Sweet, maltitol, mannitol,
sorbitol, sucralose, xylitol, alitmae, neohesperidin
dihydrochalcone, trehalose, tagatose, neotame, saccharin and salts
thereof, stevioside, erythritol, isomaltulose, polydextrose, luo
han guo, monatin, cyclamate, glycyrrhizin, osladine, sucrose,
fructose, or glucose or combinations thereof.
[0139] Non-limiting examples of flavoring agents include cherry,
grape, orange, pink lemonade, raspberry, grape, lemon, orange,
strawberry, tutti-frutti, tangerine, apple, watermelon, pineapple,
banana, peach, kiwi, mango, mixed berry, raspberry lemonade, wild
blackberry, blue raspberry, citrus, blueberry, lime, lemon lime,
grapefruit, pomegranate, pear, or plum flavors, bubble gum, or
combinations thereof.
[0140] Non-limiting examples of flavor enhancer agents include
anhydrous citric acid, citric acid monohydrate, malic acid,
tartaric acid, sodium citrate, potassium citratemonohydrate,
potassium citrate anhydrous, or sodium potassium tartate or
combinations thereof.
[0141] Non-limiting examples of coloring agents include, but are
not limited to, riboflavin, cochineal dye, carmine, blue No. 1 for
food use, yellow No. 4 aluminum lake for food use, yellow No. 5
aluminum lake for food use, red No. 3 aluminum lake for food use,
red No. 106 for food use, iron sesquioxide, yellow iron
sesquioxide, pharmaceutical dyes such as FD&C Blue No. 2,
FD&C Blue No. 1, FD&C Green No. 3, FD&C Red No. 3,
FD&C Red No. 4 , FD&C Red No. 40, FD&C Yellow No. 6,
FD&C Yellow No. 5, and the like.
[0142] The pharmaceutical formulation in the stable sachet dosage
forms described herein optionally can also comprise other
excipients, such as non-reducing sugars, such as melezitose,
planteose, and raffinose. Without intending to be bound by any
particular theory, reducing sugars may react with BH4 under certain
conditions. Other excipients useful in compositions described
herein include phosphates, such as dicalcium phosphate.
[0143] The pharmaceutical formulation in the stable sachet dosage
forms can optionally include one or more other therapeutic agents
suitable for the condition to be treated. In one embodiment the
therapeutic agent can be blended with the stable BH4
dihydrochloride powder. In another embodiment the therapeutic agent
is contained in one chamber of a dual chamber sachet and the stable
BH4 dihydrochloride dry blend powder is in the second chamber. In
one embodiment, the other therapeutic agents are selected from
folates, including, but not limited to, folate precursors, folic
acids and folate derivatives, e.g., folinic acid (leucovorin);
vitamins, such as vitamin C (ascorbic acid), vitamin B2
(riboflavin), and vitamin B12; neurotransmitter precursors, such as
L-dopa, carbidopa, and serotonin; 5-hydroxytryptophan; arginine;
and combinations thereof.
[0144] Exemplary folates, including folate precursors, folic acids,
and folate derivatives, are disclosed in U.S. Pat. Nos. 6,011,040
and 6,544,994 (each of which is incorporated herein by reference in
its entirety), and include folic acid (pteroylmonoglutamate),
dihydrofolic acid, tetrahydrofolic acid, 5-methyltetrahydrofolic
acid, 5,10-methylenetetrahydrofolic acid,
5,10-methenyltetrahydrofolic acid, 5,10-formiminotetrahydrofolic
acid, 5-formyltetrahydrofolic acid (leucovorin),
10-formyltetrahydrofolic acid, 10-methyltetrahydrofolic acid, one
or more of the folylpolyglutamates, compounds in which the pyrazine
ring of the pterin moiety of folic acid or of the
folylpolyglutamates is reduced to give dihydrofolates or
tetrahydrofolates, derivatives of all the preceding compounds in
which the N-5 or N-10 position carries one carbon unit at various
levels of oxidation, pharmaceutically acceptable salts thereof, and
combinations of two or more thereof. Exemplary tetrahydrofolates
include 5-formyl-(6S)-tetrahydrofolic acid, 5
-methyl-(6S)-tetrahydrofolic acid,
5,10-methylene-(6R)-tetrahydrofolic acid,
5,10-methynyl-(6R)-tetrahydrofolic acid,
10-formyl-(6R)-tetrahydrofolic acid,
5-formimino-(6S)-tetrahydrofolic acid, or (6S)-tetrahydrofolic
acid, and pharmaceutically acceptable salts thereof. Exemplary
salts include sodium, potassium, calcium, and ammonium salts.
Exemplary relative weight ratios of BH4 to folates to arginine can
be in a range from about 1:10:10 to about 10:1:1.
[0145] In a specific embodiment, the BH4 used in compositions
described herein is formulated as a dihydrochloride salt. Other
salt forms of BH4 possessing the desired physicochemical properties
and biological activity can also be used. For example, BH4 salts
with inorganic or organic acids are within the scope of the present
disclosure. Nonlimiting examples of alternative BH4 salt forms
include BH4 salts of acetic acid, citric acid, oxalic acid,
tartaric acid, fumaric acid, and mandelic acid. Carbonates or
hydrogen carbonates are also possible.
[0146] Pharmaceutically acceptable salts can be formed with metals
or amines, such as alkali and alkaline earth metals or organic
amines. Pharmaceutically acceptable salts of compounds can also be
prepared with a pharmaceutically acceptable cation. Suitable
pharmaceutically acceptable cations are well known to those skilled
in the art and include alkaline, alkaline earth, ammonium, and
quaternary ammonium cations. Non-limiting examples of metals used
as cations are sodium, potassium, magnesium, ammonium, calcium,
ferric, and the like. Non-limiting examples of suitable amines
include isopropylamine, trimethylamine, histidine,
N,N'-dibenzylethylenediamine, chloroprocaine, choline,
diethanolamine, dicyclohexylamine, ethylenediamine,
N-methylglucamine, and procaine.
[0147] Furthermore, the pharmaceutically acceptable salts include
inorganic and organic acid salts. Non-limiting examples of suitable
salts include hydrochlorides, acetates, citrates, salicylates,
nitrates, and phosphates. Other suitable pharmaceutically
acceptable salts are well known to those skilled in the art and
include those formed with, e.g., acetic, citric, oxalic, tartaric
or mandelic acid, hydrochloric acid, hydrobromic acid, sulfuric
acid, nitric acid or phosphoric acid; with organic carboxylic,
sulfonic, sulfo- or phosphor-acids or N-substituted sulfamic acids,
for example, acetic acid, phenylacetic acid, propionic acid,
glycolic acid, succinic acid, maleic acid, hydroxymaleic acid,
methylmaleic acid, fumaric acid, malic acid, tartaric acid, lactic
acid, oxalic acid, gluconic acid, glucaric acid, glucuronic acid,
citric acid, benzoic acid, cinnamic acid, mandelic acid, salicylic
acid, 4-aminosalicylic acid, 2-phenoxybenzoic acid,
2-acetoxybenzoic acid, embonic acid, nicotinic acid, isonicotinic
acid, methanesulfonic acid, ethanesulfonic acid,
2-hydroxyethanesulfonic acid, ethane 1,2-disulfonic acid,
benzenesulfonic acid, 4-methylbenzenesulfonic acid,
2-naphthalenesulfonic acid, naphthalene-1,5-disulfonic acid, 2- or
3-phosphoglycerate, glucose-6-phosphate, or N-cyclohexylsulfamic
acid (with the formation of cyclamates); with other acid organic
compounds, such as ascorbic acid; or with amino acids, such as the
20 alpha amino acids involved in the synthesis of proteins in
nature, e.g., glutamic acid or aspartic acid.
[0148] In an embodiment, the pharmaceutical formulation in the
stable sachet dosage forms contains about 5%, about 7.5%, about
10%, about 12.5%, about 15%, about 17.5%, about 20%, about 22.5%,
about 25%, about 27.5%, about 30%, about 32.5%, about 35%, about
37.5%, about 40%, about 42.5%, about 45%, about 47.5%, about 50%,
about 52.5%, or about 55% BH4 dihydrochloride. In certain
embodiments, the stable sachet dosage forms contain between about
10-50%, about 10-40%, about 10-30%, about 10-20%, about 20-50%,
about 30-50%, about 40-50%, or about 50-55% BH4
dihydrochloride.
[0149] In an embodiment, the pharmaceutical formulation in the
stable sachet dosage forms comprise an amount of BH4
dihydrochloride of about 15% and between 75-80% mannitol, about
0-1% sucralose, about 1.5% flavoring agent, between 4.5-7%
potassium citrate or potassium sodium tartrate, and about 1%
ascorbic acid fine powder. In a specific embodiment, the flavoring
agent is strawberry, orange on a sucrose substrate, orange on a
mannitol substrate, or grape. In another specific embodiment, the
blend also consists of about 5% potassium citrate.
[0150] In an embodiment, the pharmaceutical formulation in the
stable sachet dosage forms comprise an amount of BH4
dihydrochloride of about 15.1% BH4 dihydrochloride, 75.3% mannitol,
1.5% orange flavor on a sucrose base, 0.8% sucralose, 4.8%
potassium citrate, and 0.8% ascorbic acid fine powder.
[0151] In an embodiment, the pharmaceutical formulation in the
stable sachet dosage forms comprise an amount of BH4
dihydrochloride of about 15.3% BH4 dihydrochloride, 76.7% mannitol,
1.5% orange flavor on a mannitol base, 0.8% sucralose, 4.8%
potassium citrate, and 0.8% ascorbic acid fine powder.
[0152] In yet another embodiment, the pharmaceutical formulation in
the stable sachet dosage forms additionally comprises an amount of
5-hydroxytryptophan (5-HTP) in a range from about 0% to about 50%
by weight of the formulation. In one embodiment, the 5-HTP is dry
blended with the BH4 dihydrochloride. In another embodiment, the
5-HT is contained in one chamber of a dual chamber sachet and the
BH4 dihydrochloride is contained in the second chamber. In narrower
embodiments, the formulation additionally comprises 5-HTP from
about 5% to about 45%, or from about 10% to about 40%, or from
about 20% to about 40%, or from about 15% to about 35%, or from
about 20% to about 30%, by weight of the formulation.
[0153] In yet another embodiment, the pharmaceutical formulations
in the stable sachet dosage forms are blends that contain of
approximately 32% drug, 55% mannitol, and 1.6% to 2% sucralose. For
example:
TABLE-US-00001 Formulation A Formulation B Formulation C Ingredient
g/sachet % g/sachet % g/sachet % Sapropterin 0.2 32 0.2 32 0.2 32
HCl Mannitol 0.34 54.4 0.3388 54.2 0.3375 54.0 Sucralose 0.01 1.6
0.0113 1.8 0.0125 2.0 Potassium 0.065 10.4 0.065 10.4 0.065 10.4
Citrate Ascorbic 0.01 1.6 0.01 1.6 0.01 1.6 Acid Total 0.625 100
0.625 100 0.625 100
[0154] In yet another embodiment, the pharmaceutical formulation in
the stable sachet dosage contains approximately 32% drug, 54.1%
mannitol, 1.9% sucralose micronized, 10.4% potassium citrate
monohydrate, and 1.6% ascorbic acid fine powder.
[0155] In certain embodiments, the stable sachet dosage forms
described herein contain an amount of BH4 or a BH4-related compound
(e.g., (6R)-L-erythro-BH4 dihydrochloride) in a range from about 50
mg to about 1300 mg (i.e., 1.3 g) per sachet, or from about 100 mg
to about 1300 mg per sachet, or from about 200 mg to about 1300 mg
per sachet, or from about 300 mg to about 1300 mg per sachet, or
from about 400 mg to about 1300 mg per sachet, or from about 500 mg
to about 1300 mg per sachet, or from about 600 mg to about 1300 mg
per sachet, or from about 700 mg to about 1300 mg per sachet, or
from about 800 mg to about 1300 mg per sachet, or from about 900 mg
to about 1300 mg per sachet, or from about 1000 mg to about 1300 mg
per sachet, or from about 50 mg to about 500 mg per sachet, or from
about 100 mg to about 500 mg per sachet, or from about 200 mg to
about 500 mg per sachet, or from about 300 mg to about 500 mg per
sachet, or from about 100 mg to about 700 mg per sachet, or from
about 200 mg to about 700 mg per sachet, or from about 300 mg to
about 700 mg per sachet, or from about 400 mg to about 700 mg per
sachet. In specific embodiments, the stable sachet dosage forms
contain an initial amount of BH4 or a BH4-related compound of about
50 mg per sachet, 100 mg per sachet, or about 150 mg per sachet, or
about 160 mg per sachet, or about 200 mg per sachet, or about 250
mg per sachet, or about 300 mg per sachet, or about 350 mg per
sachet, or about 400 mg per sachet, or about 450 mg per sachet, or
about 500 mg per sachet, or about 550 mg per sachet, or about 600
mg per sachet, or about 650 mg per sachet, or about 700 mg per
sachet, or about 750 mg per sachet, or about 800 mg per sachet, or
about 850 mg per sachet, or about 900 mg per sachet, or about 950
mg per sachet, or about 1000 mg per sachet, or about 1050 mg per
sachet, or about 1100 mg per sachet, or about 1150 mg per sachet,
or about 1200 mg per sachet, or about 1250 mg per sachet, or about
1300 mg per sachet, or about 1350 mg per sachet. It will be
apparent to one skilled in the art that the desired dosage for the
treatment, amelioration or prevention of a BH4-responsive disorder
can affect the amount of BH4 or a BH4-related compound in the
sachet dosage forms.
[0156] In one embodiment, provided herein are sachet dosage forms
that contain relatively large amounts of BH4 (e.g.,
(6R)-L-erythro-BH4 dihydrochloride). A non-limiting example of such
a dosage form includes 500 mg of BH4, or 600 mg of BH4, or 700 mg
of BH4, or 800 mg of BH4, or 900 mg of BH4, or 1000 mg of BH4, or
1100 mg of BH4, or 1200 mg of BH4, or 1300 mg of BH4. Potential
advantages of relatively large amounts of BH4 available in a dosage
form include ease of providing the therapeutic, ease of oral
administration, and patient compliance.
[0157] It is particularly unexpected that weights of about 600 mg
or more, for example, of a dry blend powder have flow properties
that are amenable to automated sachet filling. Accordingly, it is
unexpected that stable sachet dosage forms described herein
contain, for example, 600 mg or more of a BH4 or BH4-related
compound dry blend powder.
[0158] In an embodiment, the stable sachet dosage forms described
herein are useful for treating BH4 deficiency or a condition or
disorder associated with BH4 deficiency (e.g.,
hyperphenylalaninemia due to BH4 deficiency). In a specific
embodiment, the stable sachet dosage is used reduce blood
phenylalanine levels in patients with hyperphenylalaninemia due to
tetrahydrobiopterin-responsive phenylketonuria. In another specific
embodiment, the stable sachet dosage is used reduce blood
phenylalanine levels in patients with hyperphenylalaninemia due to
tetrahydrobiopterin-responsive phenylketonuria in conjunction with
a phenylalanine restricted diet.
[0159] In one embodiment, the stable sachet dosage forms useful for
treating BH4 deficiency or a condition associated therewith
comprise amounts of (1) BH4 or a BH4-related compound (e.g.,
(6R)-L-erythro-BH4 dihydrochloride) from about 30% to about 60%, or
from about 40% to about 60%; (2) mannitol from about 20% to about
50%, or from about 30% to about 50%; (3) crospovidone from about 2%
to about 8%, or from about 3% to about 6%; (4) stearyl fumaric acid
or a salt form of stearyl fumarate (e.g., sodium stearyl fumarate)
from about 1% to about 4%, or from about 1% to about 3%; (5)
ascorbic acid from about 1% to about 20%, or from about 1% to about
10%; and (6) silicon dioxide (e.g., colloidal silicon dioxide) from
about 0.2% to about 4%, or from about 0.2% to about 2%, by weight
of the formulation. In a related embodiment, the stable sachet
useful for treating BH4 deficiency or a condition associated
therewith comprise an initial amount of BH4 or a BH4-related
compound (e.g., (6R)-L-erythro-BH4 dihydrochloride) in a range from
about 50 mg to about 1300 mg per sachet, including but not limited
to about 50 mg per sachet, 100 mg per sachet, or about 150 mg per
sachet, or about 160 mg per sachet, or about 200 mg per sachet, or
about 250 mg per sachet, or about 300 mg per sachet, or about 350
mg per sachet, or about 400 mg per sachet, or about 450 mg per
sachet, or about 500 mg per sachet, or about 550 mg per sachet, or
about 600 mg per sachet, or about 650 mg per sachet, or about 700
mg per sachet, or about 750 mg per sachet, or about 800 mg per
sachet, or about 850 mg per sachet, or about 900 mg per sachet, or
about 950 mg per sachet, or about 1000 mg per sachet, or about 1050
mg per sachet, or about 1100 mg per sachet, or about 1150 mg per
sachet, or about 1200 mg per sachet, or about 1250 mg per sachet,
or about 1300 mg per sachet, or about 1350 mg per sachet.
[0160] In a further embodiment, the stable sachet dosage forms
described herein are useful for treating sickle cell disease (SCD),
peripheral arterial disease (PAD), chronic kidney disease (CKD), or
hypertension. In one embodiment, the stable sachet dosage forms
useful for treating SCD, PAD, CKD, or hypertension comprise initial
amounts of (1) BH4 or a BH4-related compound (e.g.,
(6R)-L-erythro-BH4 dihydrochloride) from about 30% to about 60%, or
from about 40% to about 60%, or from about 40% to about 50%; (2)
ascorbic acid from about 30% to about 60%, or from about 40% to
about 60%, or from about 40% to about 50%; (3) crospovidone from
about 2% to about 8%, or from about 3% to about 6%; (4) stearyl
fumaric acid or a salt form of stearyl fumarate (e.g., sodium
stearyl fumarate) from about 1% to about 4%, or from about 1% to
about 3%; (5) silicon dioxide (e.g., colloidal silicon dioxide)
from about 0.2% to about 4%, or from about 0.2% to about 2%; and
(6) 5-methyltetrahydrofolate (5-MTHF) or a salt form thereof from
about 0% to about 2%, or from about 0.01% to about 1%, or from
about 0.01% to about 0.5%, by weight of the formulation. The 5-MTHF
can be a pharmaceutically acceptable salt of 5-MTHF, e.g., the
calcium salt of 5-MTHF. In a related embodiment, the stable sachets
useful for treating SCD, PAD, CKD, or hypertension comprise initial
amounts of BH4 or a BH4-related compound (e.g., (6R)-L-erythro-BH4
dihydrochloride) and ascorbic acid in a weight ratio of about 10:1,
about 9:1, about 8:1, about 7:1, about 6:1, about 5:1, about 4:1,
about 3:1, about 2.5:1, about 2:1, about 1.5:1, about 1:1, about
1:1.5, or about 1:2. In another related embodiment, the stable
sachets useful for treating SCD, PAD, CKD, or hypertension comprise
an initial amount of BH4 or a BH4-related compound (e.g.,
(6R)-L-erythro-BH4 dihydrochloride) in a range from about 50 mg to
about 1300 mg per sachet, including but not limited about 50 mg per
sachet, 100 mg per sachet, or about 150 mg per sachet, or about 160
mg per sachet, or about 200 mg per sachet, or about 250 mg per
sachet, or about 300 mg per sachet, or about 350 mg per sachet, or
about 400 mg per sachet, or about 450 mg per sachet, or about 500
mg per sachet, or about 550 mg per sachet, or about 600 mg per
sachet, or about 650 mg per sachet, or about 700 mg per sachet, or
about 750 mg per sachet, or about 800 mg per sachet, or about 850
mg per sachet, or about 900 mg per sachet, or about 950 mg per
sachet, or about 1000 mg per sachet, or about 1050 mg per sachet,
or about 1100 mg per sachet, or about 1150 mg per sachet, or about
1200 mg per sachet, or about 1250 mg per sachet, or about 1300 mg
per sachet, or about 1350 mg per sachet.
[0161] In a particular embodiment of a stable sachet dosage form
useful for treating SCD, PAD, CKD, or hypertension, the
pharmaceutical formulation of the dosage form comprises the
following ingredients, in terms of weight % of the formulation and
mg per capsule: (1) 46.75% (6R)-L-erythro-BH4 dihydrochloride
(250.0 mg); (2) 46.75% ascorbic acid (250.0 mg); (3) 3.98% or 3.96%
crospovidone (21.3 mg or 21.2 mg); (4) 1.75% sodium stearyl
fumarate (9.4 mg); (5) 0.75% colloidal silicon dioxide (4.0 mg);
and (6) 0.02% or 0.04% 5-methyltetrahydrofolate, calcium salt (0.1
mg or 0.2 mg).
[0162] In another particular embodiment, the stable sachet dosage
form can be used for treating or ameliorating autism. BH4 has been
shown to be effective in treating autism in humans (see, e.g.,
Fernell et al., Dev. Med. & Child Neurology, 39: 313-318
(1997); Frye et al. Neurotherapeutics, 7: 241-249; Danfors et al.,
J. Clinical Psychopharmacology, 25(5): 485-489). Fernell shows that
children treated with BH4 for 4, 8, and 12 weeks had significant
increases in their total scores on the Parental Satisfaction Survey
("PSS"). Fernell, Table II, page 316. Frye reviews research using
BH4 to treat autism and concludes that BH4 represents a novel
therapy for autism spectrum disorder. Danfors shows that children
treated with BH4 had significant improvement of their social
interaction scores after 6 months of treatment and found a high
positive correlation between response of the social interaction
score and IQ.
[0163] In one embodiment, the BH4 or BH4-related compound can be
used for treating or ameliorating austism in children. In one
embodiment, the BH4 or BH4-related compound can be used for
treating or ameliorating autism in adults. In a particular
embodiment, the BH4 or BH4-related compound can be administered in
conjunction with a second pharmaceutical composition to treat or
ameliorate the symptoms of autism. In a particular embodiment, the
second pharmaceutical compound for the combination treatment can be
selected from groups consisting of stimulants, antidepressants,
antianxiety medications, non-stimulant ADHD medications,
antipsychotics, mood stabilizers, or Alzheimer's medications.
[0164] Sachet dosage forms can be manufactured by dry blending the
components of the sachet and sealing them in a single or dual
chamber sachet. The sachet can be flushed with an inert gas and
hermetically sealed. The sachet can also contain a desiccant. The
sachet can be made out of Mylar foil. Further, the sachet can then
be filled with the compounded material and, optionally, the capsule
can be stored in a sealed container, e.g., a Mylar foil package.
The Mylar foil package may contain a desiccant and may be flushed
with inert gas and may be hermetically sealed. The compounded
pharmaceutical components or powder blends can be uniformly filled
into sachets using an automated sachet-filling equipment or can be
manually filled into sachets, as is known in the art.
[0165] In an embodiment, the stable sachet dosage forms, including
the pharmaceutical formulations contained therein, are made by a
process that does not include adding an aqueous liquid. The dry
blend manufacturing process comprises a dry process of mixing and
blending an initial amount of the active ingredient, BH4 or a
BH4-related compound (e.g., (6R)-L-erythro-BH4 dihydrochloride),
with an initial amount of an excipient that optionally has been
screened with an appropriate mesh screen, optionally mixing and
blending the resulting ingredients with an initial amount of a
second excipient that optionally has been screened, optionally
doing the same with additional excipients, and filling the
resulting dry blend of ingredients into capsules.
[0166] In another embodiment, the methods involve the step of
informing the patient that absorption of tetrahydrobiopterin is
increased when it is ingested with food compared to when ingested
without food. In some embodiments, the patient is informed that
ingestion shortly following a meal, for example, a high-fat,
high-calorie meal, results in an increase in any one, two, three or
all of the following parameters: mean plasma concentration, Cmax,
AUC, AUC(0-t) and/or AUC(inf). In other embodiments, the patient is
informed that administration of BH4 with a high-fat meal increases
Cmax and AUC compared to administration of BH4 without food (in a
fasting condition). In some embodiments, the relative increase can
be at least 20% or 30% or more.
[0167] In another embodiment, such methods involve administering
BH4, whether swallowed as a solid or semisolid dosage form, or
dissolved in a liquid, with food, e.g., a high-fat food or a
high-fat and/or high-calorie meal. In another embodiment, BH4,
whether swallowed or dissolved, is administered at a specified time
including but not limited to morning, day, night, same time of the
day, with food, e.g., a high-fat food or a high-fat and/or
high-calorie meal, one or more times a day. In another embodiment,
BH4 is ingested once daily as a solid dosage form just after meals.
In another embodiment the solid dosage form is a formulated tablet
or capsule. In other embodiments, BH4 is ingested within
approximately 0 to 30 minutes, or 5 to 20 minutes, of eating a
meal.
[0168] The BH4 and the food may be ingested at approximately the
same time, or the BH4 may be ingested before or after the food. The
period of time between consuming the food and taking BH4, either
swallowed or dissolved, may be at least 5 minutes. For example, BH4
may be administered 60 minutes, 30 minutes, 25 minutes, 20 minutes,
15 minutes, 10 minutes, or 5 minutes before or after a meal.
[0169] In another embodiment, to maximize oral bioavailability of
BH4 at each administration, BH4 should be taken with food, e.g., a
high fat food or a high fat and/or high calorie meal.
Alternatively, to maximize consistency of oral bioavailability
between administrations, BH4 should be taken on an empty stomach
(e.g., 1 hour before or 2 hours after a meal).
[0170] The container or packaging containing BH4 sachet dosage
forms is selected, inter alia, to minimize or prevent moisture
penetration into and contamination of the formulation in the dosage
form and thereby enhance the stability of the formulation. In an
embodiment, BH4 sachet dosage forms are disposed in a sealed
container or packaging. Examples of sealed containers include Mylar
foil pouches. Additional non-limiting examples of sealed containers
or packaging include polyethylene bottles, e.g., high density
polyethylene bottles closed with a heat-induction seal, glass
bottles, tubes, hermetically sealed foil packaging, thermally
sealed polyethylene bags, laminated foil pouches, and blister
packs. In one embodiment, a desiccant is disposed in the container
or packaging containing the BH4 sachet dosage forms, or is
incorporated in the closure, stopper or cap of the container or
packaging. In one embodiment the container is flushed with inert
gas prior to being hermetically sealed.
[0171] In another embodiment, at least about 90% of the initial
amount of the BH4 or BH4-related compound remains, after the sachet
dosage form is stored at about 40.degree. C. and about 75% RH for a
period of about three months. In another embodiment, at least about
91%, or at least about 92%, or at least about 93%, or at least
about 94%, or at least about 95%, or at least about 96%, or at
least about 97%, or at least about 98%, or at least about 99% of
the initial amount of BH4 or BH4-related compound remains after the
sachet dosage form is stored at about 40.degree. C. and about 75%
RH for a period of about three months.
[0172] In another embodiment, at least about 85% of the initial
amount of the BH4 or BH4-related compound dissolves within about 15
minutes, after the sachet dosage form is stored at about 40.degree.
C. and about 75% RH for a period of about three months. In another
embodiment, at least about 86%, or at least 87%, or at least 88%,
or at least 89%, or at least 90%, or at least 91%, or at least 92%,
or at least 93%, or at least 94%, or at least 95%, or at least 96%,
or at least 97%, or at least 98%, or at least 99% of the initial
amount of the BH4 or BH4-related compound dissolves within about 15
minutes, after the sachet dosage form is stored at about 40.degree.
C. and about 75% RH for a period of about three months.
[0173] In another embodiment, at least about 90%, or at least about
91%, or at least about 92%, or at least about 93%, or at least
about 94%, or at least about 95%, or at least about 96%, or at
least about 97%, or at least about 98%, or at least about 99% of
the initial amount of the BH4 or BH4-related compound remains and
at least about 85%, or at least about 86%, or at least 87%, or at
least 88%, or at least 89%, or at least 90%, or at least 91%, or at
least 92%, or at least 93%, or at least 94%, or at least 95%, or at
least 96%, or at least 97%, or at least 98%, or at least 99% of the
initial amount of the BH4 or BH4-related compound dissolves within
about 15 minutes, after the sachet dosage form is stored at about
40.degree. C. and about 75% RH for a period of about three
months.
[0174] In another embodiment, at least about 85%, or at least about
86%, or at least 87%, or at least 88%, or at least 89%, or at least
90%, or at least 91%, or at least 92%, or at least 93%, or at least
94%, or at least 95%, or at least 96%, or at least 97%, or at least
98%, or at least 99% of the initial amount of the BH4 or
BH4-related compound dissolves within about 1 minute, or within
about 2 minutes, or within about 3 minutes, or within about 4
minutes, or within about 5 minutes, or within about 6 minutes, or
within about 7 minutes, or within about 8 minutes, or within about
9 minutes, or within about 10 minutes with gentle agitation, after
the sachet dosage form is stored at about 40.degree. C. and about
75% RH for a period of about three months. In certain embodiments
the gentle agitation is stirring or shaking.
[0175] In another embodiment, at least about 90%, or at least about
91%, or at least about 92%, or at least about 93%, or at least
about 94%, or at least about 95%, or at least about 96%, or at
least about 97%, or at least about 98%, or at least about 99% of
the initial amount of the BH4 or BH4-related compound remains and
at least about 85%, or at least about 86%, or at least 87%, or at
least 88%, or at least 89%, or at least 90%, or at least 91%, or at
least 92%, or at least 93%, or at least 94%, or at least 95%, or at
least 96%, or at least 97%, or at least 98%, or at least 99% of the
initial amount of the BH4 or BH4-related compound dissolves within
about 1 minute, or within about 2 minutes, or within about 3
minutes, or within about 4 minutes, or within about 5 minutes, or
within about 6 minutes, or within about 7 minutes, or within about
8 minutes, or within about 9 minutes, or within about 10 minutes
with gentle agitation, after the sachet dosage form is stored at
about 40.degree. C. and about 75% RH for a period of about three
months. In certain embodiments the gentle agitation is stirring or
shaking.
Therapeutic Methods Using Stable Dosage Forms
[0176] It will be appreciated that therapeutic methods applicable
to the stable dosage forms described herein include the fields of
human medicine and veterinary medicine. Thus, the subject to be
treated can be a mammal, e.g., human or other animal.
[0177] The stable dosage forms described herein can be used for
treating, ameliorating or preventing, e.g., conditions associated
with elevated phenylalanine levels or decreased tyrosine or
tryptophan levels. Such conditions may be caused, for example, by
reduced phenylalanine hydroxylase activity or reduced tyrosine
hydroxylase or tryptophan hydroxylase activity. Conditions
associated with elevated phenylalanine levels include, e.g.,
phenylketonuria, both mild and classic, and hyperphenylalanemia
(also written as hyperphenylalaninemia), and exemplary patient
populations include the patient subgroups described herein as well
as any other patients exhibiting phenylalanine levels above normal.
Conditions associated with reduced tyrosine or tryptophan levels
include, e.g., neurotransmitter deficiency, neurological and
psychiatric disorders such as Parkinson's, dystonia,
spinocerebellar degeneration, pain, fatigue, depression, other
affective disorders, and schizophrenia. Non-limiting examples of
other BH4-responsive conditions that can be treated, ameliorated or
prevented by use of the BH4 stable capsule dosage forms described
herein include BH4 deficiency, sickle cell anemia, hypertension and
autism.
[0178] Genetic disorders resulting in hyperphenylalaninemia (HPA)
involve deficiency in the enzyme phenylalanine hydroxylase (PAH),
which causes phenylketonuria (PKU), and deficiency in the essential
PAH cofactor, tetrahydrobiopterin (BH4), which causes disorders
known as BH4 deficiency. BH4 is an essential cofactor for several
enzymes, including PAH, tyrosine hydroxylase, tryptophan
hydroxylase, all three nitric oxide synthetase (NOS) isoforms, and
glyceryl-ether monooxygenase. BH4 deficiency can result from
defects in the genes encoding the enzymes involved in BH4 synthesis
(GTP cyclohydrolase 1 (GTP-CH 1), 6-pyruvoyl-tetrahydropterin
synthase (PTPS) and sepiapterin reductase (SR)) or BH4 regeneration
(dihydropteridine reductase (DHPR) and pterin-4-carbinolamine
dehydratase (PCD, also called 4a-carbinolamine dehydratase)). In
addition to elevated blood phenylalanine levels (HPA), patients
with defects in BH4 metabolism can suffer progressive neurologic
deterioration due to decreased production of the neurotransmitters
dopamine, epinephrine, norepinephrine and serotonin.
[0179] The BH4 stable dosage forms described herein can be used to
treat, ameliorate or prevent BH4 deficiency associated with
deficiency in or reduced activity of any one or any combination of
the enzymes involved in BH4 synthesis or recycling--GTP-CH 1, PTPS,
SR, DHPR and PCD. For example, the BH4 stable dosage forms can be
used to treat, ameliorate or prevent hyperphenylalanemia due to BH4
deficiency and associated with deficiency in or reduced activity of
any one or any combination of the aforementioned enzymes. The BH4
stable dosage forms can also be used to treat, ameliorate or
prevent hyperphenylalanemia due to phenylketonuria. In an
embodiment, the BH4 stable dosage forms can be administered in
conjunction with a low phenylalanine diet; with the
neurotransmitter precursors L-dopa, carbidopa and/or serotonin;
with folinic acid (leucovorin) or a salt form of folinate (e.g.,
calcium folinate), e.g., in the case of DHPR deficiency; or with
any combinations thereof.
[0180] Suitable subjects for treatment with the stable dosage forms
described herein include subjects with an elevated plasma Phe
concentration in the absence of the therapeutic, e.g., greater than
about 180 uM, greater than about 200 uM, greater than about 300 uM,
greater than about 400 uM, greater than about 500 uM, greater than
about 600 uM, greater than about 800 uM, greater than about 1,000
uM, greater than about 1,200 uM, greater than about 1,400 uM,
greater than about 1,600 uM, or greater than about 1,800 uM. Mild
PKU is generally classified as plasma Phe concentrations of up to
about 600 uM, moderate PKU as plasma Phe concentrations of between
about 600 uM and about 1,200 uM, and classic or severe PKU as
plasma Phe concentrations that are greater than about 1,200 uM.
Treatment with the dosage form alone or with a protein-restricted
diet can decrease the plasma phenylalanine concentration of a
subject to less than about 600 uM, less than about 500 uM, less
than about 400 uM, less than about 350 uM, less than about 300 uM,
less than about 250 uM, less than about 200 uM, less than about 150
uM, or less than about 100 uM.
[0181] Other suitable subjects include subjects diagnosed as having
a reduced phenylalanine hydroxylase (PAH) activity. Reduced PAH
activity may result from a mutation in the PAH enzyme, for example,
a mutation in the catalytic domain of PAH or one or more mutations
selected from the group consisting of F39L, L48S, I65T, R68S,
A104D, S110C, D129G, E178G, V190A, P211T, R241C, R261Q, A300S,
L308F, A313T, K320 N, A373T, V388M E390G, A395P, P407S, and
Y414C.
[0182] Further, other suitable subjects can include pregnant
females, females of child-bearing age who are contemplating
pregnancy, infants between 0 and 3 years of age (e.g., 0-2, 0-1.5
or 0-1 year old), and subjects diagnosed as being unresponsive
within 24 hours to a single-dose BH4 loading test or a multiple
dose loading test, such as a 4-dose or 7-day loading test.
Exemplary patient populations and exemplary BH4 loading tests are
described in WO 2005/049000, which is incorporated herein by
reference in its entirety.
[0183] U.S. Pat. Nos. 4,752,573; 4,758,571; 4,774,244; 4,920,122;
5,753,656; 5,922,713; 5,874,433; 5,945,452; 6,274,581; 6,410,535;
6,441,038; and 6,544,994; and U.S. Application Publication Nos. US
2002/0187958; US 2002/0106645; US 2002/0076782; and US 2003/0032616
(each incorporated herein by reference in its entirety), each
describe methods of administering BH4 compositions for non-PKU
treatments. Each of these patent documents is incorporated herein
by reference as teaching methods of administering BH4 compositions
known to those of skill in the art, which can be adapted for the
therapeutic method described herein, as well as teaching related
conditions that can also be treated by applying the present
disclosure.
[0184] While individual needs may vary, determination of the
optimal range of the effective amount of the active ingredient and
the optimal administration regimen is within the skill of an
ordinary artisan. Exemplary dosages of BH4 or a BH4-related
compound can range from about 1 to about 30 mg/kg body weight per
day, which may amount to about 5 (1 mg/kg33 5 kg body weight) to
3,000 mg/day (30 mg/kg.times.100 kg body weight). Dosages of BH4 or
a BH4-related compound can also range from about 2 to about 20
mg/kg/day. One embodiment is directed to daily administration of a
BH4 capsule dosage form for a continuous period of time. For
hyperphenylalanemia, however, it may be desirable to cease the BH4
therapy when the symptoms of Phe levels are reduced to below a
certain threshold level. Of course, the BH4 therapy can be
reinitiated in the event that Phe levels rise again. Appropriate
dosages can be ascertained through use of established assays for
determining blood levels of Phe in conjunction with relevant dose
response data.
[0185] In an embodiment, the method of the present disclosure
provides to a patient a daily dose of between about 10 mg/kg and
about 20 mg/kg of BH4 or a BH4-related compound. Of course, one
skilled in the art can adjust (i.e., increase or decrease) the dose
depending on the efficacy achieved by the administration. The daily
dose can be administered in a single dose or alternatively can be
administered in multiple doses at conveniently spaced intervals. In
exemplary embodiments, the mg/kg daily dose of BH4 or a BH4-related
compound can be 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
16, 17, 18, 19, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44,
46, 48, 50, 55, 60, 65, 70 or more mg/kg body weight per day.
[0186] The BH4 stable dosage forms described herein can also be
used to treat subjects suffering from conditions or disorders that
would benefit from enhancement of nitric oxide synthase (NOS)
activity and subjects suffering from vascular diseases, ischemic or
inflammatory diseases, or insulin resistance. Unless expressly
indicated otherwise, the term "nitric oxide synthase" or "NOS"
refers to all the isoforms of NOS, i.e., endothelial nitric oxide
synthase (eNOS), neuronal nitric oxide synthase (nNOS), and
inducible nitric oxide synthase (iNOS). The BH4 treatment can,
e.g., alleviate a deficiency in NOS activity or can, e.g., provide
an increase in NOS activity over normal levels.
[0187] Nitric oxide is constitutively produced by vascular
endothelial cells, where it plays a key physiological role in the
regulation of blood pressure and vascular tone. A deficiency in
nitric oxide bioactivity may be involved in the pathogenesis of
vascular dysfunctions, including coronary artery disease,
atherosclerosis of any arteries, including coronary, carotid,
cerebral and peripheral vascular arteries, ischemia-reperfusion
injury, hypertension, diabetes, diabetic vasculopathy,
cardiovascular disease, peripheral vascular disease, and
neurodegenerative conditions stemming from ischemia and/or
inflammation, such as stroke. Such pathogenesis includes damaged
endothelium, insufficient oxygen flow to organs and tissues,
elevated systemic vascular resistance (high blood pressure),
vascular smooth muscle proliferation, progression of vascular
stenosis (narrowing) and inflammation. In an embodiment, the BH4
capsule dosage forms described herein can be used to treat any of
the aforementioned conditions.
[0188] Enhancement of nitric oxide synthase activity may also
result in reduction of superoxide levels, increased insulin
sensitivity, and reduction in vascular dysfunction associated with
insulin resistance, as described in U.S. Pat. No. 6,410,535, which
is incorporated herein by reference in its entirety. Thus, the BH4
dosage forms described herein can also be used to treat diabetes
(type I and type II), hyperinsulinemia, and insulin resistance.
Diseases having vascular dysfunction associated with insulin
resistance include those caused by insulin resistance or aggravated
by insulin resistance, or those for which cure is retarded by
insulin resistance, such as hypertension, hyperlipidemia,
arteriosclerosis, coronary vasoconstrictive angina, effort angina,
cerebrovascular constrictive lesion, cerebrovascular insufficiency,
cerebral vasospasm, peripheral circulation disorder, coronary
arteriorestenosis following percutaneous transluminal coronary
angioplasty (PTCA) or coronary artery bypass grafting (CABG),
obesity, insulin-independent diabetes, hyperinsulinemia, lipid
metabolism abnormality, coronary arteriosclerotic heart diseases,
and like conditions that are associated with insulin
resistance.
[0189] Moreover, the BH4 dosage forms described herein can be used
to treat drug-induced renal injury. The BH4 treatment can recover
the functions of endothelial cells and normalize the functions of
NOS to provide renal protective effects. Clinical states of
drug-induced renal injury are typically classified into acute renal
failure and chronic renal failure, as described in U.S. Pat. No.
6,288,067, which is incorporated herein by reference in its
entirety.
[0190] When administered to patients susceptible to or suffering
from any of the aforementioned disorders, BH4 or a BH4-related
compound can treat or prevent these disorders by activating the
functions of NOS, increasing NO production, and suppressing the
production of active oxygen species (e.g., superoxide), to improve
disorders of vascular endothelial cells.
[0191] A subject suffering from a deficiency in nitric oxide
synthase (NOS) activity may benefit from co-treatment with BH4 or a
BH4-related compounds, and folic acids, folates, folate precursors,
or folate derivatives. Accordingly, in one embodiment, provided
herein is use of stable capsule dosage forms comprising BH4 or a
BH4-related compounds and a folic acid, folate, folate precursor,
or folate derivative for treating, ameliorating or preventing
cardiovascular or neurological disorders by modulation of the
activity of a nitric oxide synthase (NOS). Modulation of the
activity of an NOS can, e.g., reduce superoxide (O.sub.2.)
production, enhance nitric oxide (NO) synthesis, and influence NO
levels. U.S. Pat. Nos. 6,995,158, 6,544,994; and 6,011,040, each of
which is incorporated herein by reference in its entirety, describe
the use of BH4 and a folic acid or folate compound to modulate NOS
activity.
[0192] Non-limiting examples of folic acids, folates, folate
precursors, and folate derivatives that can be used in the present
disclosure include folic acid (pteroylmonoglutamate), dihydrofolic
acid, dihydrofolates, tetrahydrofolic acid, 5-methyltetrahydrofolic
acid, 5,10-methylenetetrahydrofolic acid,
5,10-methenyltetrahydrofolic acid, 5,10-formiminotetrahydrofolic
acid, 5-formyltetrahydrofolic acid (leucovorin),
10-formyltetrahydrofolic acid, 10-methyltetrahydrofolic acid,
tetrahydrofolates, folylpolyglutamates, compounds in which the
pyrazine ring of the pterin moiety of folic acid or of the
folylpolyglutamates is reduced to give dihydrofolates or
tetrahydrofolates, derivatives of all the preceding compounds in
which the N-5 or N-10 position carries one carbon unit at various
levels of oxidation, pharmaceutically acceptable salts of all the
preceding compounds, and combinations thereof. In an embodiment,
the BH4-containing formulation comprises an initial amount of a
folic acid, a folate, a folate precursor or a folate derivative
(e.g., folic acid or 5-methyltetrahydrofolate) in a range from
about 0.0005% to about 5%, or to about 3%, or to about 1%, or to
about 0.5%, or to about 0.1%, or to about 0.05% by weight of the
formulation.
[0193] Exemplary tetrahydrofolic acids and tetrahydrofolates
include 5-formyl-(6S)-tetrahydrofolic acid,
5-methyl-(6S)-tetrahydrofolic acid,
5,10-methylene-(6R)-tetrahydrofolic acid,
5,10-methenyl-(6R)-tetrahydrofolic acid,
10-formyl-(6R)-tetrahydrofolic acid,
5-formimino-(6S)-tetrahydrofolic acid, (6S)-tetrahydrofolic acid,
and pharmaceutically acceptable salts thereof. Exemplary salts of
all the folic acid and folate compounds described herein include
sodium, potassium, calcium, and ammonium salts thereof.
[0194] The pharmaceutical formulation comprising BH4 or a
BH4-related compound and a folic acid, folate, folate precursor, or
folate derivative, can further comprise one or more other active or
adjuvant substances. In one embodiment, the one or more other
active or adjuvant substances include arginine (e.g., L-arginine).
L-arginine is a precursor of endogenous nitric oxide (NO), a potent
vasodilator acting via the intracellular second messenger cGMP.
L-arginine induces peripheral vasodilation and inhibits platelet
aggregation due to increased NO production. A lack of NO production
has been linked to pathological conditions, including
cardiovascular disorders (e.g., atherosclerosis), septic shock,
inflammation and infection, and brain damage in stroke and
neurological disorders. In an embodiment, the formulation comprises
BH4 or a BH4-related compound, a folic acid or a folate (which can
also be a folate precursor or a folate derivative), and arginine
each in a unit dosage from about 0.1 mg to about 250 mg. In another
embodiment, the weight ratio of BH4 or a BH4-related compound to a
folic acid or a folate to arginine ranges from about 1:10:10 to
about 10:1:1.
[0195] In another embodiment, the pharmaceutical formulation
comprising BH4 or a BH4-related compound can be used to treat or
ameliorate autism. In a particular embodiment, the BH4 or
BH4-related compound is BH4 dihydrochloride. In a particular
embodiment, BH4 dihydrochloride can be administered to children
suffering from autism. In particular embodiment, the child is about
0-18 years old, 1-18 years old, about 2-18 years old, about 3-18
years old, about 3-17 years old, about 3-16 years old, about 3-15
years old, about 3-14 years old, about 3-13 years old, about 3-12
years old, about 3-11 years old, about 3-10 years old, about 3-9
years old, about 3-8 years old, about 3-7 years old, or about 3-6
years old. In a particular embodiment, the is administered to a
subject during childhood and adulthood. In a particular embodiment,
the formulation can be administered at a dosage of about 5 - 50
mg/kg/day. In a particular embodiment, the formulation can be
administered at a dosage of about 5 mg/kg/day, or about 7.5
mg/kg/day, or about 10 mg/kg/day, or about 10.5 mg/kg/day, or about
11 mg/kg/day, or about 11.5 mg/kg/day, or about 12 mg/kg/day, or
about 12.5 mg/kg/day, or about 13 mg/kg/day, or about 13.5
mg/kg/day, or about 14 mg/kg/day, or about 14.5 mg/kg/day, or about
15 mg/kg/day, or about 15.5 mg/kg/day, or about 16 mg/kg/day, or
about 16.5 mg/kg/day, or about 17 mg/kg/day, or about 17.5
mg/kg/day, or about 18 mg/kg/day, or about 18.5 mg/kg/day, or about
19 mg/kg/day, or about 19.5 mg/kg/day, or about 20 mg/kg/day. In
another embodiment, the pharmaceutical formulation comprising BH4
or a BH4-related compound can be used to treat or ameliorate autism
at a dosage of 25 mg/kg/day or more.
[0196] It is understood that the suitable dose will depend upon
various factors, such as the age, health, weight, and diet of the
recipient, the kind of concurrent treatment, if any, the frequency
of treatment, and the nature of the effect desired (e.g., the
amount of decrease in plasma Phe concentration desired). The
frequency of dosing also depends on the pharmacodynamic effects of
a BH4 dosage form. For example, if the pharmacological effects of a
single dose of a BH4 capsule dosage form last for about 24 hours,
the BH4 capsule dosage form can be administered once daily.
Alternatively, a BH4 dosage form can be administered two or more
times a day at appropriate time intervals in cases where multiple
daily administrations to a particular subject are deemed to be more
effective for treating, ameliorating or preventing a particular
BH4-responsive condition. One or more BH4 doses can be administered
in a particular time of administration. For example, 1 BH4 dosage
can be taken orally per day. As another example, 2 BH4 doses can be
taken orally per day--e.g., 2 capsules or sachets once daily or 1
capsule or sachet twice daily. As yet another example, 3 BH4 doses
can be taken orally per day--e.g., 3 capsules or sachets once
daily, 2 capsules or sachets and 1 capsule or sachet at two
different times, or 1 capsule or sachet thrice daily. As a further
example, 4 BH4 doses can be taken orally per day--e.g., 4 capsules
or sachets once daily, 2 capsules or sachets twice daily, 2
capsules or sachets and 2.times.1 capsule or sachets at three
different times, or 1 capsule or sachet four times daily. As still
another example, 6 BH4 doses can be taken orally per day--e.g., 6
capsules or sachets once daily, 3 capsules or sachets twice daily,
4 capsules or sachets and 2 capsules or sachets at two different
times, or 2 capsules or sachets thrice daily. The desired dosage of
the active ingredient, BH4 or a BH4-related compound, in a stable
dosage form and the frequency of administration of the dosage form
can be tailored to the individual subject and the particular
BH4-responsive condition(s) being treated, as is understood and
determinable by one of skill in the art, without undue
experimentation. For example, a standard dose can be adjusted
according to the facts and circumstances of a particular patient,
e.g., reduction of the dose if the patient has a low body
weight.
[0197] In addition, the frequency of BH4 dosing will depend on the
pharmacokinetic parameters of the active ingredient and the
route/mode of administration. The optimal features of a BH4 capsule
or sachet dosage form can be determined by one of skill in the art
depending on various factors, such as the route of administration
and the desired dosage. See, e.g., Remington's Pharmaceutical
Sciences, 18th Ed., pp. 1435-1712, Mack Publishing Co. (Easton,
Pennsylvania, 1990), which is incorporated herein by reference.
Depending on the route/mode of administration, a suitable dose can
be calculated according to body weight, body surface areas or organ
size. Further refinement of the calculations for determining the
appropriate treatment dose is routinely made by those of ordinary
skill in the art without undue experimentation, including in light
of the dosage information and assays disclosed herein as well as
the pharmacokinetic data observed in animals or human clinical
trials.
[0198] The final dosage regimen will be determined by the attending
physician, considering factors that may affect the action of the
drug, e.g., the drug's specific activity, the severity of the
damage, the responsiveness of the patient, the age, condition, body
weight, sex and diet of the patient, the severity of any infection,
the time and frequency of administration, and other clinical
factors. As studies are conducted, further information will emerge
regarding appropriate dosage levels and duration of treatment for
specific diseases and conditions.
Combination Therapy
[0199] In one embodiment, the BH4 dosage forms described herein can
be used in combination with one or more other therapeutic agents.
In such combination therapy, administration of the BH4 dosage forms
can be concurrent with or can precede or follow the administration
of a second therapeutic agent, e.g., by intervals ranging from
minutes to hours. BH4 or a BH4-related compound and the other
therapeutic agent(s) can exert their pharmacological effects at
overlapping or non-overlapping time periods. The disclosure
encompasses the use of one or more additional therapeutic agents in
the preparation of a pharmaceutical composition for use with BH4 or
a BH4-related compound. The composition containing the additional
therapeutic agent(s) can also contain BH4 or a BH4-related compound
or can be distinct from the capsule formulation containing BH4 or a
BH4-related compound.
[0200] Tetrahydrobiopterin therapy can be combined with dietary
protein restriction to effect a therapeutic outcome in patients
with various forms of hyperphenylalaninemia (HPA). For example, a
subject can be administered a BH4 dosage form and a low
phenylalanine medical protein composition in a combined amount
effective to produce the desired therapeutic outcome, i.e., a
lowering of plasma Phe concentration and/or the ability to tolerate
greater amounts of Phe/protein intake without producing a
concomitant increase in plasma Phe concentrations. The process can
involve administering the BH4 dosage form and the dietary protein
therapeutic composition at about the same time. This can be
achieved by administering a single dosage form, or the dietary
protein (supplement or normal protein meal) can be taken at about
the same time as the BH4 dosage form.
[0201] Alternatively, the BH4 treatment can precede or follow the
dietary protein therapy by intervals ranging from minutes to hours.
The protein composition and the BH4 dosage form can be administered
separately such that the BH4 will still be able to exert an
advantageous effect on the patient. For example, the BH4 dosage
form can be administered within about 1-6 hours (before or after)
of the dietary protein intake. In a more specific example, the
delay time between BH4 and dietary protein administrations can be
about one hour. In one embodiment, the BH4 therapy is a continuous
therapy wherein a daily dose of BH4 is administered to the patient
continuously. In another embodiment, e.g., in pregnant women having
only the milder forms of PKU or HPA, the BH4 therapy is only
continued for as long as the woman is pregnant and/or breast
feeding.
[0202] In another embodiment, the therapeutic method provided
herein is a combination therapy that administers BH4 or a
BH4-related compound and a composition that specifically targets
one or more of the symptoms of HPA. For example, the deficit in
tyrosine associated with HPA results in a deficiency in the
neurotransmitters dopamine and serotonin. Thus, a BH4 stable dosage
form can be administered in combination with the neurotransmitter
precursors L-dopa, carbidopa and/or 5-hydroxytryptophan, with or
without dietary protein therapy, to correct defects that result
from decreased amounts of tyrosine in the body.
[0203] In antoehr embodiment, the therapeutic method provided
herein is a combination therapy that administers BH4 or a
BH4-related compound and a composition that specifically targets
one or more of the symptoms of autisim. For example, medications
for depression, anxiety, ADD/ADHD, mood stabilization, and
Alzheimer's disease can be used in combination therapy with BH4 or
a BH4-related compounds to treat or ameliorate the symptoms of
austism. More specifically, for example stimulants (i.e., ADD/ADHD
treatment) administered in conjunction with the BH4 or BH4-related
compound to treat and ameliorate autism may include but are not
limited to amphetamines, methylphenidate, pemoline,
dextroamphetamines, dexmethylphenidate, methylphenidate, and
combinations thereof; non-stimulants (i.e., ADD/ADHD treatment)
administered in conjunction with the BH4 or BH4-related compound to
treat and ameliorate autism may include but is not limited to
atomoxetine; antidepressants and anti-anxiety medications
administered in conjunction with the BH4 or BH4-related compound to
treat and ameliorate autism may include but are not limited to
clomipramine, buspirone, buspirone, fluvoxamine, paroxetine,
fluoxetine, nefazodone, doxepin, imipramine, bupropion, sertraline,
and combinations thereof; mood stabilizing medications administered
in conjunction with the BH4 or BH4-related compound to treat and
ameliorate autism may include but are not limited to lithium
citrate, valproic acid, lithium carbonate, carbamazepine, and
combinations thereof; and an Alzheimer's medication administered in
conjunction with the BH4 or BH4-related compound to treat and
ameliorate autism may include but is not limited to memantine
HCl.
[0204] In addition, gene therapy with phenylalanine hydroxylase
(PAH) (Christensen et al., Mol. Genetics Metabol., 76: 313-318
(2002); Christensen et al., Gene Therapy, 7: 1971-1978 (2000)) or
phenylalanine ammonia lyase (PAL) (Liu et al., Arts. Cells. Blood.
Subs. and Immob. Biotech., 30: 243-257 (2002)) can be employed.
Such gene therapy techniques can be used in combination with BH4
therapy and/or dietary protein restriction. In other combination
therapies, phenylase can be provided as an injectable enzyme to
further lower Phe concentrations in the patient. Because
administration of phenylase would not generate tyrosine (unlike
administration of PAH), phenylase treatment would still result in
tyrosine being an essential amino acid for such patients.
Therefore, dietary supplementation with tyrosine may be desired for
patients receiving phenylase in combination with BH4 therapy.
Representative Embodiments
[0205] The following representative embodiments of the disclosure
are given merely to illustrate the disclosure and are not intended
to limit the scope of the disclosure.
[0206] In one embodiment, provided herein is a stable capsule
dosage form comprising a pharmaceutical formulation comprising an
initial amount of (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in the crystalline form designated polymorph B, and
one or more pharmaceutically acceptable excipients, wherein the
capsule has a shell that is essentially free of pullulan, and at
least about 95%, at least about 96%, at least about 97%, at least
about 98%, at least about 99%, or at least about 99.5% of the
initial amount of the tetrahydrobiopterin dihydrochloride remains
after the capsule dosage form is stored in a container at about
25.degree. C. and about 60% relative humidity, or at about
40.degree. C. and about 75% relative humidity, for a period of
about 3 months, about 4 months, about 5 months, about 6 months,
about 9 months, about 12 months (one year), about 18 months, about
24 months (two years), about 30 months, or about 36 months (three
years).
[0207] In an embodiment, at least about 70%, at least about 75%, at
least about 80%, at least about 85%, at least about 90%, at least
about 95%, at least about 97%, or at least about 99% of the initial
amount of the tetrahydrobiopterin dihydrochloride in the stable
capsule dosage form dissolves within about 10 minutes, about 15
minutes, about 20 minutes, about 25 minutes, or about 30 minutes
after the capsule dosage form has been stored in the container at
about 25.degree. C. and about 60% relative humidity, or at about
40.degree. C. and about 75% relative humidity, for a period of
about 3 months, about 4 months, about 5 months, about 6 months,
about 9 months, about 12 months, about 18 months, about 24 months,
about 30 months, or about 36 months, wherein the dissolution is
determined according to U.S.P. Method II at 50 r.p.m. in 0.1 N
hydrochloric acid maintained at 37.degree. C.
[0208] In a particular embodiment, the container is a heat
induction-sealed, screw cap high-density polyethylene (HDPE)
bottle. In another embodiment, the HDPE bottle is sealed in a foil
pouch. In another particular embodiment, the container is a foil
blister pack. In an embodiment, the container contains a desiccant.
In another embodiment, the container contains no desiccant.
[0209] In an embodiment, the initial amount of the
tetrahydrobiopterin dihydrochloride in the capsule dosage form is
in a range from about 100 mg to about 500 mg. In specific
embodiments, the initial amount of the tetrahydrobiopterin
dihydrochloride is about 100 mg, about 150 mg, about 160 mg, about
200 mg, about 250 mg, about 300 mg, about 350 mg, about 400 mg,
about 450 mg, or about 500 mg per capsule.
[0210] In one embodiment, the shell of the capsule is made of or
comprises one or more substances selected from the group consisting
of cellulose derivatives; hydroxypropyl methylcellulose (HPMC);
starch derivatives; carrageenans; acacia; gelatin; polyethylene
glycol; homopolymers and copolymers formed from polyvinyl alcohol,
acrylic acid, and methyl methacrylate; and combinations thereof. In
a specific embodiment, the shell of the capsule is made of or
comprises gelatin. In another specific embodiment, the shell of the
capsule is made of or comprises hydroxypropyl methylcellulose.
[0211] In one embodiment, provided herein is a stable powder dosage
comprising a pharmaceutical formulation comprising an initial
amount of a BH4 or BH4-related compound in pre-blended, powder
(i.e., crystalline) form, wherein the powder is pre-mixed and
blended to be dissolved in solution. In a specific embodiment, the
BH4 or BH4-related compound is (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride, designated polymorph B. In a specific embodiment,
the pharmaceutical formulation comprises an additional one or more
pharmaceutically acceptable excipients. In a specific embodiment,
the pharmaceutical formulation comprises
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride, a sweetener, a
flavoring agent, and a flavor enhancer.
[0212] In another specific embodiment, the pre-blended powder
formulation comprises the BH4 or BH4-related compound, a sweetener,
a flavoring agent, one or more fillers, and a flavor enhancer is a
dry blend. In a specific embodiment, the BH4 or BH4-related
compound is (6R)-L-erythro-tetrahydrobiopterin dihydrochloride. In
certain embodiments, the formation is prepared by blending the
fillers with the BH4 or BH4 compound and flavor enhancer in a
blender to achieve a adequate mixture, further blending a portion
of the blended mixture with acesulfame potassium or sucralose, a
flavoring agent, and ascorbic acid and thereafter passing that
mixture through a suitable sieve (e.g., 20 mesh sieve), and lastly
blending the second mixture with the remainder of the first mixture
until the blend is homogenous.
[0213] In a specific embodiment, the sweetener is acesulfam
potassium, isomalt, Magna Sweet, maltitol, mannitol, sorbitol,
sucralose, xylitol, alitmae, neohesperidin dihydrochalcone,
trehalose, tagatose, neotame, saccharin and salts thereof,
stevioside, erythritol, isomaltulose, polydextrose, luo han guo,
monatin, cyclamate, osladine, sucrose, fructose, or glucose or
combinations thereof. In a specific embodiment, the flavor enhancer
is anhydrous citric acid, citric acid monohydrate, malic acid,
tartic acid, sodium citrate, potassium citrate dehydrate, or sodium
potassium tartate or combinations thereof. In a specific
embodiment, the flavoring agent is a cherry, grape, orange, pink
lemonade, raspberry, grape, lemon, orange, strawberry,
tutti-frutti, tangerine, apple, watermelon, pineapple, banana,
peach, kiwi, mango, mixed berry, raspberry lemonade, wild
blackberry, blue raspberry, citrus, blueberry, lime, lemon lime,
grapefruit, pomegranate, pear, or plum flavors or combinations
thereof and the sieve is a 20 mesh sieve.
[0214] In another specific embodiment, the pre-blended powder
formulation comprises 6R)-L-erythro-tetrahydrobiopterin
dihydrochloride (i.e., BH4 dihydrochloride), the flavor enhancer is
citrate, the sweeteners is mannitol, the flavoring agent is orange,
and an additional taste masking agent is sucralose.
[0215] In another embodiment, the powder dosage is packaged in a
single chamber sachet or a dual chamber sachet. In a specific
embodiment, the dual chamber sachet separates incompatible
components. In a specific embodiment, the dual chamber sachet
comprises one chamber that contains the active BH4 powder blend and
a second chamber that contains the flavor blend. In a specific
embodiment, the sachets comprise of an additional active agent for
combination therapy.
[0216] In another embodiment, the sachets are sealed in Mylar foil
pouches. In a specific embodiment, a desiccant is included in the
sachets or in the foil pouches.
[0217] In another embodiment, the amount of the BH4 or BH4 compound
in the sachet dosage form is in a range from about 100 mg to about
1300 mg (i.e., 1.3 g). In specific embodiments, the initial amount
of the tetrahydrobiopterin dihydrochloride is about 100 mg, about
150 mg, about 160 mg, about 200 mg, about 250 mg, about 300 mg,
about 350 mg, about 400 mg, about 450 mg, about 500 mg, about 550
mg, about 600 mg, about 650 mg, about 700 mg, about 750 mg, about
800 mg, about 850 mg, about 900 mg, about 950 mg, about 1000 mg,
about 1050 mg, about 1100 mg, about 1150 mg, about 1200 mg, about
1250 mg, or about 1300 mg per sachet.
[0218] In another embodiment, the sachets are filled with 600 mg or
more, for example, of the BH4 or BH4-related compound powder blend
wherein the unexpected flowability of the dry blend powder
formulation allows for automated sachet filling.
[0219] In another embodiment, the final dosage strength after the
active BH4 or BH4 compound from the sachet dosage is dissolved in
an aqueous solution with the flavor blend is about 10 mg/mL. In
specific embodiments, the final dosage strength is about 1 mg/mL,
about 2 mg/mL, 3 mg/mL, about 4 mg/mL, about 4.5 mg/mL, about 5
mg/mL, about 5.5 mg/mL, about 6 mg/mL, about 6.5 mg/mL, about 7
mg/mL, about 7.5 mg/mL, about 8 mg/mL, about 8.5 mg/mL, about 9
mg/mL, about 9.5 mg/mL, about 10 mg/mL, about 10.5 mg/mL, about 11
mg/mL, about 12 mg/mL, about 13 mg/mL, about 14 mg/mL, about 15
mg/mL, or about 20 mg/mL.
[0220] In a further embodiment, the pharmaceutical formulations in
the stable capsule and sachet dosage forms comprise one or more
pharmaceutically acceptable excipients selected from the group
consisting of ascorbic acid, silicon dioxide, mannitol,
microcrystalline cellulose, crospovidone, povidone, stearyl fumaric
acid, salt forms of stearyl fumarate, dicalcium phosphate,
5-methyltetrahydrofolate (5-MTHF), salt forms of 5-MTHF, and
combinations thereof. In an embodiment, the one or more excipients
include crospovidone and stearyl fumaric acid or a salt form of
stearyl fumarate. In another embodiment, the one or more excipients
further include ascorbic acid, silicon dioxide and mannitol.
[0221] In a particular embodiment, the pharmaceutical formulation
in the stable capsule comprises an initial amount of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride in a range from
about 30% to about 60%, crospovidone from about 3% to about 6%,
sodium stearyl fumarate from about 1% to about 3%, ascorbic acid
from about 1% to about 10%, silicon dioxide from about 0.2% to
about 2%, and mannitol from about 20% to about 50% by weight of the
formulation. In another particular embodiment, the pharmaceutical
formulation comprises an initial amount of (6R)-L-erythro-BH4
dihydrochloride from about 40% to about 50%, ascorbic acid from
about 40% to about 50%, crospovidone from about 3% to about 6%,
sodium stearyl fumarate from about 1% to about 3%, silicon dioxide
from about 0.2% to about 2%, and calcium salt of
5-methyltetrahydrofolate from about 0.01% to about 0.5% by weight
of the formulation.
[0222] In another embodiment, the capsule and sachet formulations
comprising (6R)-L-erythro-tetrahydrobiopterin dihydrochloride and
one or more pharmaceutically acceptable excipients further comprise
5-hydroxytryptophan. In a particular embodiment, the formulation
comprises an initial amount of 5-hydroxytryptophan in a range from
about 20% to about 40% by weight of the formulation.
[0223] In yet another embodiment, the stable capsule and sachet
dosage forms, including the pharmaceutical formulation therein, are
made by a process that does not include adding liquid water. In an
embodiment, the pharmaceutical formulation is made by mixing
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride and the one or
more pharmaceutically acceptable excipients, without addition of
liquid water. In an embodiment, the pharmaceutical formulation made
without addition of liquid water is ground to a powder and packaged
in dual chamber sachets. In certain embodiments each sachet is a
single dose or multiple doses. In an embodiment, the pharmaceutical
formulation made without addition of liquid water is the active
ingredient of the stable BH4 capsules.
[0224] In a further embodiment, provided herein is a method of
treating, ameliorating or preventing hyperphenylalanemia due to BH4
deficiency, comprising administering to a subject in need thereof a
therapeutically effective amount of the BH4-containing stable
capsule dosage and sachet forms described herein. In one
embodiment, the capsule and sachet dosage forms are administered
orally once daily. In another embodiment, the capsule and sachet
dosage forms are administered orally twice daily.
[0225] In an embodiment, the stable capsule and sachet dosage forms
are used to treat, ameliorate or prevent hyperphenylalanemia due to
BH4 deficiency which is associated with deficiency in or reduced
activity of any one or any combination of the enzymes GTP
cyclohydrolase 1 (GTP-CH 1), 6-pyruvoyl-tetrahydropterin synthase
(PTPS), sepiapterin reductase (SR), dihydropteridine reductase
(DHPR), and pterin-4-carbinolamine dehydratase (PCD).
[0226] In a particular embodiment, the stable capsule and sachet
dosage forms used to treat, ameliorate or prevent
hyperphenylalanemia due to BH4 deficiency comprises a formulation
comprising an initial amount of (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in a range from about 30% to about 60%,
crospovidone from about 3% to about 6%, sodium stearyl fumarate
from about 1% to about 3%, ascorbic acid from about 1% to about
10%, silicon dioxide from about 0.2% to about 2%, and mannitol from
about 20% to about 50% by weight of the formulation. In another
embodiment, the formulation further comprises an initial amount of
5-hydroxytryptophan in a range from about 20% to about 40% by
weight of the formulation.
[0227] In an embodiment, the stable capsule and sachet dosage forms
are used to treat or ameliorate autism. In a particular embodiment,
the stable capsule and sachet dosage is used to treat or ameliorate
autism in children. In a particular embodiment, the stable capsule
and sachet dosage is used to treat or ameliorate autism in adults.
In a particular embodiment, the stable capsule and sachet dosage is
used in a combination therapy with an additional medication(s) to
treat or ameliorate autism.
EXAMPLES
[0228] The following examples are provided merely for illustration
and are not intended to limit the scope of the disclosure.
Example 1
Dry Process for Making Capsule Dosage Forms
[0229] The active ingredient, (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride or a BH4-related compound, and all the excipients
were separately pre-screened through an appropriate size mesh
(e.g., #20 mesh screen). A powder blend for filling capsules was
prepared by mixing the active ingredient with a glidant (e.g.,
colloidal silicon dioxide) using a high shear mixer until a
homogenous mix was obtained. The mix was added to a suitable
blender (e.g., V-blender) and blended with the remaining excipients
(e.g., mannitol, ascorbic acid and crospovidone) except for the
lubricant. A portion of the powder blend was removed from the
blender and added to the lubricant (e.g., sodium stearyl fumarate)
to obtain a pre-mix. The pre-mix was mixed in a suitable vessel and
then passed through a screen with appropriate mesh opening (e.g.,
#20 mesh screen). The resulting material was returned to the
blender for a final mixing. The desired amount of the final powder
blend was filled into capsules (e.g., size 0 or size 00 gelatin or
hydroxypropyl methylcellulose capsules) and the capsules were then
closed with their cap.
Example 2
Stability of Various Capsule Dosage Forms
[0230] Certain embodiments of the capsule dosage forms of the
present disclosure are illustrated in Table 1, with a comparison
tablet dosage form. The (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride (BH4.2HCl) in all six capsule examples and the
comparison tablet in Table 1 was in the form of polymorph B. Table
2 summarizes stability data for the Table 1 dosage forms in gelatin
and HPMC capsules stored in heat induction-sealed, screw cap high
density polyethylene (HDPE) bottles at 40.degree. C. and about 75%
relative humidity (accelerated stability conditions), and
comparison data for tablets of Table 1 stored in heat
induction-sealed, HDPE bottles at 40.degree. C. and about 75%
relative humidity or stored in foil blister cards under the same
conditions. None of the gelatin capsule and HPMC capsule packagings
in Table 2 contained a desiccant and the tablet foil blister cards
also did not contain a desiccant, while the tablet HDPE bottles
contained a desiccant. Table 2 demonstrates the ability of various
capsule dosage forms to provide stable BH4 dihydrochloride over at
least six months under the accelerated stability conditions.
[0231] FIGS. 2 and 3 show the dissolution profiles (the rate of
dissolution of BH4 dihydrochloride from the dosage form according
to U.S.P. Method II at 50 r.p.m. in 0.1 N hydrochloric acid at
37.degree. C.) after the capsule dosage forms have been stored at
40.degree. C. and about 75% relative humidity. FIG. 2 shows the
dissolution profile of BH4 dihydrochloride in the HPMC capsule
dosage form of Example 3 in Table 1. FIG. 3 shows the dissolution
profile of BH4 dihydrochloride in the gelatin capsule dosage form
of Example 1 in Table 1. As evident from FIGS. 2 and 3, the
dissolution rates of the BH4 dihydrochloride contained in the HPMC
and gelatin capsules were maintained over the duration of the
stability studies (six months), which is a factor in maintaining
the pharmacokinetic properties (e.g., bioavailability) of BH4 over
time.
[0232] FIG. 4 compares the stability of BH4 capsule dosage forms
that have been stored in heat induction-sealed HDPE bottles or heat
induction-sealed HDPE bottles sealed in foil pouches at 40.degree.
C. and about 75% relative humidity, to the stability of BH4 tablets
stored in heat induction-sealed HDPE bottles or foil blister cards
under the same conditions (the stability data are given in Table
2). Storage in HDPE bottles sealed in foil pouches mimics storage
in foil blister cards. None of the BH4 capsule packagings contained
a desiccant and the tablet-containing foil blister cards also did
not contain a desiccant, while the tablet-containing HDPE bottles
contained a desiccant. The BH4 dihydrochloride in all of these
stability studies of the capsules and tablets was in the form of
polymorph B.
[0233] As demonstrated in Table 2 and FIG. 4, all of the
BH4-containing HPMC and gelatin capsule dosage forms exhibited a
very small percentage (0.4% or less) of total impurities after
being stored without a desiccant for 6 months at 40.degree. C. and
about 75% relative humidity. As explained above, a capsule dosage
form normally is not recommended for a hygroscopic,
moisture-sensitive active ingredient such as BH4 dihydrochloride
because BH4 dihydrochloride would be expected to absorb water from
the material (e.g., gelatin or HPMC) in the capsule shell and
consequently become labile to oxidation. For example, U.S. Pat. No.
4,917,885 teaches that when a hard gelatin capsule is stored under
"a highly humid condition," the active ingredient therein can be
"denatured due to the increased moisture inside the capsule," and
thus "the quality of a gelatin-made hard capsule is unavoidably
degraded in the lapse of time." Contrary to conventional wisdom,
the capsule dosage forms provided herein comprise BH4
dihydrochloride that possesses unexpected stability over a
prolonged period of time at elevated temperature and high
humidity.
TABLE-US-00002 TABLE 1 BH4-Containing Formulations of Capsules and
Tablets Ingredients Stable Capsule Lots wt % Ex. 1 Ex. 2 Ex. 3 Ex.
4 Ex. 5 Ex. 6 Tablet BH4.cndot.2HCl 46.75 47.13 46.75 46.75 46.75
47.13 33.33 Ascorbic 46.75 47.13 23.38 23.38 0.00 0.00 1.67 Acid
granular Silicon 0.75 0.00 0.75 0.00 0.75 0.00 0.00 Dioxide
Mannitol 0.00 0.00 23.38 24.13 46.75 47.13 57.56 Dicalcium 0.00
0.00 0.00 0.00 0.00 0.00 2.18 phosphate Crospovidone 4.00 4.00 4.00
4.00 4.00 4.00 4.50 Sodium 1.75 1.75 1.75 1.75 1.75 1.75 0.75
Stearyl Fumarate Riboflavin 0.00 0.00 0.00 0.00 0.00 0.00 0.01
Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0
TABLE-US-00003 TABLE 2 Stability of BH4 Capsules and Tablets Stored
at 40.degree. C. and about 75% Humidity Total Impurity (%) 3 6 Lot
No. Capsule Type Packaging Initial months months Ex. 1a Gelatin
capsule HDPE bottle 0.23 0.3 0.41 Ex. 2a Gelatin capsule 0.22 0.20
0.40 Ex. 3a HPMC capsule 0.18 0.22 0.29 Ex. 3b Gelatin capsule 0.19
0.20 0.39 Ex. 4a HPMC capsule 0.20 0.17 0.29 Ex. 4b Gelatin capsule
0.21 0.18 0.37 Ex. 5a HPMC capsule 0.26 0.20 0.32 Ex. 5b Gelatin
capsule 0.24 0.25 0.42 Ex. 6a HPMC capsule 0.26 0.19 0.30 Ex. 6b
Gelatin capsule 0.26 0.21 0.39 Ex. 1b Gelatin capsule HDPE 0.23
0.30 0.26 Ex. 2b Gelatin capsule bottle sealed 0.22 0.20 0.23 Ex.
3c HPMC capsule in a 0.18 0.24 0.25 Ex. 3d Gelatin capsule foil
pouch 0.19 0.18 0.25 Ex. 4c HPMC capsule 0.20 0.17 0.23 Ex. 4d
Gelatin capsule 0.21 0.18 0.23 Ex. 5c HPMC capsule 0.26 0.21 0.24
Ex. 5d Gelatin capsule 0.24 0.22 0.24 Ex. 6c HPMC capsule 0.26 0.21
0.26 Ex. 6d Gelatin capsule 0.26 0.21 0.23 Tablet HDPE bottle 0.25
0.39 0.47 Tablet Foil blister card 0.05 0.29 0.44
Example 3
HPMC Capsules Containing 160 mg BH4 Dihydrochloride
[0234] Table 3 describes the formulation of a stable capsule dosage
form comprising 160 mg (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in polymorphic form B, wherein the shell of the
capsule comprises hydroxypropyl methylcellulose (HPMC).
TABLE-US-00004 TABLE 3 Formulation of HPMC Capsules Containing 160
mg BH4 2HCl Ingredients Function Weight % mg/capsule BH4
Dihydrochloride Active 50.00 160.0 Mannitol Diluent 38.50 123.2
Ascorbic Acid Granular Antioxidant 5.00 16.0 Colloidal Silicon
Dioxide Glidant 0.75 2.4 Crospovidone Disintegrant 4.00 12.8 Sodium
Stearyl Fumarate Lubricant 1.75 5.6 Total 100.00 320.0
[0235] The 160 mg BH4 capsule dosage form of Table 3 was prepared
in the following manner. The active ingredient,
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride in polymorphic
form B, and all the excipients were individually pre-screened
through a #20 mesh screen. Pre-screened BH4 dihydrochloride and
colloidal silicon dioxide were dry mixed in a plastic bag for 2 min
by shaking. The mixture was screened through a #20 mesh screen, and
then mixed at 600 rpm for 10 min using a high shear mixer. The
resulting mixture was placed into a V-blender, and pre-screened
ascorbic acid, crospovidone and mannitol were added. The mixture
was mixed for 10 min. Pre-screened sodium stearyl fumarate was
added, and the mixture was mixed for 5 min. The powder blend was
passed through a #20 mesh screen. The resulting formulation, having
the amounts of ingredients per capsule as shown in Table 3, was
filled into size 0 HPMC capsules using a prefill filling
system.
[0236] HPMC capsules comprising the formulation of Table 3 were
stored in heat induction-sealed, high-density polyethylene (HDPE)
bottles containing no desiccant at 25.degree. C. and about 60%
relative humidity (RH) (normal stability conditions), and
alternatively at 40.degree. C. and about 75% relative humidity
(accelerated stability conditions). Tables 4 and 5 show that the
160 mg BH4 HPMC capsules, after storage in HDPE bottles under
normal and accelerated stability conditions for 3 months, exhibited
no significant changes in capsule quality, potency and purity. For
example, the capsules contained only 0.26% total impurities after 6
months of storage under accelerated stability conditions, i.e.,
only a 0.15% increase in level of total impurities. In addition,
FIG. 5 demonstrates that the dissolution rate of the 160 mg BH4
dihydrochloride contained in the HPMC capsules, according to U.
S.P. Method II, essentially did not change after the capsules were
stored for 1, 3, and 6 months under accelerated stability
conditions.
TABLE-US-00005 TABLE 4 Stability of 160 mg BH4 HPMC Capsules Stored
at 25.degree. C. and about 60% RH HPMC Capsules Containing 160 mg
BH4 2HCl Heat induction-sealed HDPE bottles without desiccant
Storage Conditions: 25.degree. C./60% relative humidity Time Points
(months) Test 0 1 3 QUALITY Appearance of capsule White to off-
White to off- White to off- white capsule white capsule white
capsule Appearance of capsule Light yellow Light yellow Light
yellow content powder powder powder POTENCY Assay by HPLC 95.2%
96.5% 101.7% PURITY Related Substances (HPLC) Biopterin ND ND 0.02%
Dihydrobiopterin ND ND 0.03% R-Tetrahydrobiolumazine 0.03% 0.04%
0.05% S-Tetrahydrobiopterin 0.03% 0.02% 0.04% Tetrahydropterin
0.05% 0.04% 0.06% Individual Unidentified ND ND ND Total
Unidentified ND ND ND Total 0.11% 0.10% 0.20% ND = Not Detected RRT
= Relative Retention Time
TABLE-US-00006 TABLE 5 Stability of 160 mg BH4 HPMC Capsules Stored
at 40.degree. C. and about 75% RH HPMC Capsules Containing 160 mg
BH4 2HCl Heat induction-sealed HDPE bottles without desiccant
Storage Conditions: 40.degree. C./75% relative humidity Time Points
(months) Test 0 1 3 QUALITY Appearance of capsule White to off-
White to off- White to off- white capsule white capsule white
capsule Appearance of capsule Light yellow Light yellow Light
yellow content powder powder powder POTENCY Assay by HPLC 95.2%
99.0% 98.7% PURITY Related Substances (HPLC) Biopterin ND 0.02%
0.05% Dihydrobiopterin ND 0.02% 0.06% R-Tetrahydrobiolumazine 0.03%
0.04% 0.06% S-Tetrahydrobiopterin 0.03% 0.02% 0.03%
Tetrahydropterin 0.05% ND 0.06% Individual Unidentified ND ND ND
Total Unidentified ND ND ND Total 0.11% 0.10% 0.26% ND = Not
Detected RRT = Relative Retention Time
Example 4
HPMC Capsules Containing 200 mg BH4 Dihydrochloride
[0237] Table 6 describes the formulation of a stable capsule dosage
form comprising 200 mg (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in polymorphic form B, wherein the shell of the
capsule comprises hydroxypropyl methylcellulose (HPMC). This
capsule dosage form was prepared in a manner similar to the
preparative procedure described in Example 3.
TABLE-US-00007 TABLE 6 Formulation of HPMC Capsules Containing 200
mg BH4 2HCl Ingredients Function Weight % mg/capsule BH4
Dihydrochloride Active 50.00 200.0 Mannitol Diluent 41.00 164.0
Ascorbic Acid Fine Powder Antioxidant 2.50 10.0 Colloidal Silicon
Dioxide Glidant 0.75 3.0 Crospovidone Disintegrant 4.00 16.0 Sodium
Stearyl Fumarate Lubricant 1.75 7.0 Total 100.00 400.0
[0238] HPMC capsules comprising the formulation of Table 6 were
stored in heat induction-sealed, HDPE bottles containing no
desiccant at 40.degree. C. and about 75% relative humidity. As
evident from Table 7, the 200 mg BH4 HPMC capsules showed no
significant changes in capsule quality, potency and purity after
being stored in HDPE bottles under accelerated stability conditions
for 6 months. For example, the capsules contained only 0.29% total
impurities after 6 months of storage under accelerated stability
conditions, which was only a 0.1% increase in level of total
impurities. Further, FIG. 6 shows that the dissolution profile of
the 200 mg BH4 dihydrochloride contained in the HPMC capsules,
according to U. S.P. Method II, did not significantly change after
the capsules were stored for 3 months under accelerated stability
conditions.
TABLE-US-00008 TABLE 7 Stability of 200 mg BH4 HPMC Capsules Stored
at 40.degree. C. and about 75% RH HPMC Capsules Containing 200 mg
BH4 2HCl Heat induction-sealed HDPE bottles without desiccant
Storage Conditions: 40.degree. C./75% relative humidity Time Points
(months) Test 0 3 6 QUALITY Appearance of capsule White to off-
White to off- White to off- white capsule white capsule white
capsule Appearance of capsule Light yellow Light yellow Light
yellow content powder powder POTENCY Assay by HPLC 92.7% 93.1%
91.2% PURITY Related Substances (HPLC) Biopterin ND 0.03% 0.06%
Dihydrobiopterin 0.03% 0.05% 0.06% R-Tetrahydrobiolumazine 0.05%
0.05% 0.06% S-Tetrahydrobiopterin 0.04% 0.03% 0.03%
Tetrahydropterin 0.06% 0.03% 0.07% Individual Unidentified 0.04%
0.03% 0.005% (RRT = 1.3) (RRT = 1.3) Total Unidentified ND ND
0.005% Total 0.18% 0.19% 0.29% ND = Not Detected RRT = Relative
Retention Time
[0239] The effect of storage with a desiccant on the stability of
BH4 dihydrochloride was also evaluated. HPMC capsules comprising
the formulation of Table 6 were stored in heat induction-sealed
HDPE bottles containing varying amounts of silica gel desiccant for
6 months at 40.degree. C. and about 75% relative humidity. As
evident from Table 8, storage of the HPMC capsules in HDPE bottles
containing increasing amounts of silica gel desiccant under
accelerated stability conditions had no effect on the stability of
BH4 dihydrochloride. With or without a desiccant, the 200 mg BH4
HPMC capsules contained a slightly higher amount of total
impurities (0.29%) after 6 months of storage under accelerated
stability conditions as they did prior to storage (0.18%).
TABLE-US-00009 TABLE 8 Effect of Desiccant on Stability of BH4 HPMC
Capsules Stored at 40.degree. C./75% RH HPMC Capsules Containing
200 mg BH4.cndot.2HCl Heat induction-sealed HDPE bottles with
varying amounts of silica gel desiccant Storage Conditions:
40.degree. C./75% relative humidity Time (month) and Amount (g) of
Desiccant 3 mo 3 mo 3 mo 6 mo 6 mo 6 mo Test 0 mo 0 g 1 g 2 g 0 g 1
g 2 g Quality Appearance of capsule White White White White White
White to White to to to off- to to off- to off-white off-white
off-white white off-white white off-white Appearance of capsule
Light Light Light Light Light Light Yellow content yellow yellow
yellow yellow yellow yellow Purity Related Substances (HPLC)
Biopterin ND 0.03% 0.02% 0.03% 0.06% 0.04% 0.05% Dihydrobiopterin
0.03% 0.05% 0.06% 0.07% 0.06% 0.07% 0.07% R-Tetrahydrobiolumazine
0.05% 0.05% 0.06% 0.04% 0.06% 0.05% 0.05% S-Tetrahydrobiopterin
0.04% 0.03% 0.03% 0.02% 0.03% 0.03% 0.04% Tetrahydropterin 0.06%
0.03% 0.02% 0.02% 0.07% 0.08% 0.07% Individual Unidentified ND ND
ND ND 0.005% 0.005% 0.009% (RRT = 0.5) (RRT = 0.5) 0.005% 0.006%
(RRT = 0.6) (RRT = 0.6) Total Unidentified ND ND ND ND 0.005% 0.01%
0.015% Total 0.18% 0.19% 0.19% 0.18% 0.29% 0.28% 0.29% ND = Not
Detected RRT = Relative Retention Time
[0240] The dissolution profile of the 200 mg BH4 dihydrochloride
contained in the HPMC capsules, according to U.S.P. Method II,
slightly differed depending on whether the capsules were stored in
HDPE bottles with or without a desiccant for 3 months under
accelerated stability conditions. FIG. 7 shows that storage with
silica gel desiccant slightly decreased the dissolution lag time of
the BH4 dihydrochloride and slightly sped up its dissolution.
TABLE-US-00010 TABLE 9 HPMC Capsules Containing 200 mg BH4
Dihydrochloride with Sucralose Ingredients Function Weight %
mg/capsule BH4 Dihydrochloride Active 50.00 200.0 Mannitol Diluent
37.00 148.0 Ascorbic Acid Fine Powder Antioxidant 2.50 10.0
Colloidal Silicon Dioxide Glidant 0.75 3.0 Sucralose Sweetener 4.00
16.0 Crospovidone Disintegrant 4.00 16.0 Sodium Stearyl Fumarate
Lubricant 1.75 7.0 Total 100.00 400.0
[0241] HPMC capsules comprising the formulation of Table 9 were
stored in heat induction-sealed, HDPE bottles with varying amounts
of silica gel desiccant at 40.degree. C. and about 75% relative
humidity. As evident from FIG. 9, storage of the HPMC capsules in
HDPE bottles containing increasing amounts of silica gel desiccant
under accelerated stability conditions is detrimental to the
physical stability of BH4 dihydrochloride; black specks were
observed in the powder content of the capsules stored with 1 g and
2 g of desiccant after 6 months. Stability of the capsule stored
without desiccant remains acceptable after 6 months of storage at
40.degree. C./&5% RH. As evident from Table 10, the 200 mg BH4
HPMC capsules without desiccant showed insignificant change in
capsule quality, potency and purity after being stored in HDPE
bottles under accelerated stability conditions for 6 months. For
example, the capsules contained only 0.29% total impurities after 6
months of storage under accelerated stability conditions, which was
only about 0.1% increase in level of total impurities.
TABLE-US-00011 TABLE 10 Stability of BH4 HPMC Capsules (with
sucralose) Stored at 40.degree. C./75% RH HPMC Capsules Containing
200 mg BH4 2HCl Heat induction-sealed HDPE bottles without silica
gel desiccant Storage Conditions: 40.degree. C./75% relative
humidity Time (month) Test 0 mo 3 mo 6 mo Quality Appearance of
capsule White to White to White to off-white off-white off-white
Appearance of capsule Light yellow Light yellow Yellow content
Potency BH4 95.1% 92.2% 94.1% Purity Related Substances (HPLC)
Biopterin ND 0.03% 0.06% Dihydrobiopterin 0.03% 0.06% 0.06%
R-Tetrahydrobiolumazine 0.05% 0.05% 0.06% S-Tetrahydrobiopterin
0.04% 0.02% 0.03% Tetrahydropterin 0.06% 0.03% 0.07% Individual
Unidentified ND ND 0.003% (RRT = 0.51) 0.005% (RRT = 0.63) Total
Unidentified ND ND 0.008% Total 0.18% 0.19% 0.29%
Example 5
HPMC Capsules Containing 250 mg BH4 Dihydrochloride
[0242] Table 11 describes the formulation of a stable capsule
dosage form comprising 250 mg (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in polymorphic form B, wherein the shell of the
capsule comprises hydroxypropyl methylcellulose (HPMC). This
capsule dosage form was prepared in a manner similar to the
preparative procedure described in Example 3, wherein the order of
addition of ingredients was BH4 dihydrochloride and silicon
dioxide, followed by ascorbic acid and crospovidone, then followed
by 5-methyltetrahydrofolate, and finally followed by sodium stearyl
fumarate.
TABLE-US-00012 TABLE 11 Formulation of HPMC Capsules Containing 250
mg BH4 2HCl Ingredients Function Weight % mg/capsule BH4
Dihydrochloride Active 46.75 250.0 Ascorbic Acid Granular
Antioxidant 46.75 250.0 Colloidal Silicon Dioxide Glidant 0.75 4.0
Crospovidone Disintegrant 3.96 21.2 Sodium Stearyl Fumarate
Lubricant 1.75 9.4 5-Methyltetrahydrofolate, Dietary 0.04 0.2
Calcium Salt Supplement Total 100.00 534.8
[0243] HPMC capsules comprising the formulation of Table 11 were
stored in heat induction-sealed, high-density polyethylene (HDPE)
bottles containing no desiccant at 25.degree. C. and about 60%
relative humidity (normal stability conditions), and alternatively
at 40.degree. C. and about 75% relative humidity (accelerated
stability conditions). Tables 12 and 13 show that the 250 mg BH4
HPMC capsules, after storage in HDPE bottles under normal and
accelerated stability conditions for 3 month, displayed no
significant changes in capsule quality, potency and purity. For
example, the capsules contained only 0.25% total impurities after 3
month of storage under normal stability conditions, which was only
a 0.15% increase in level of total impurities, and the capsules
contained only 0.0.3% total impurities after 3 month of storage
under accelerated stability conditions, which was only an increase
of 0.2% total impurities.
TABLE-US-00013 TABLE 12 Stability of 250 mg BH4 HPMC Capsules
Stored at 25.degree. C. and about 60% RH HPMC Capsules Containing
250 mg BH4 2HCl Heat induction-sealed HDPE bottles without
desiccant Storage Conditions: 25.degree. C./60% relative humidity
Time Points (months) Test 0 1 3 QUALITY Appearance of capsule White
to off- White to off- White to off white capsule white capsule
white capsule Appearance of capsule Light yellow Light yellow Light
yellow content powder powder powder POTENCY Assay by HPLC 99.7%
101.3% 102.3% PURITY Related Substances (HPLC) Biopterin ND 0.01%
0.02% Dihydrobiopterin ND 0.02% 0.04% R-Tetrahydrobiolumazine 0.04%
0.03% 0.05% S-Tetrahydrobiopterin 0.03% 0.02% 0.04%
Tetrahydropterin 0.03% ND 0.10% Individual Unidentified ND 0.03%
(RRT = 0.72) ND Total Unidentified ND 0.03% ND Total 0.10% 0.11%
0.25% ND = Not Detected RRT = Relative Retention Time
TABLE-US-00014 TABLE 13 Stability of 250 mg BH4 HPMC Capsules
Stored at 40.degree. C. and about 75% RH HPMC Capsules Containing
250 mg BH4 2HCl Heat induction-sealed HDPE bottles without
desiccant Storage Conditions: 40.degree. C./75% relative humidity
Time Points (months) Test 0 1 3 QUALITY Appearance of capsule White
to off- White to off- White to off- white capsule white capsule
white capsule Appearance of capsule Light yellow Light yellow Light
yellow content powder power powder POTENCY Assay by HPLC 99.7%
96.8% 101.9% PURITY Related Substances (HPLC) Biopterin ND 0.02%
0.04% Dihydrobiopterin ND 0.03% 0.07% R-Tetrahydrobiolumazine 0.04%
0.03% 0.06% S-Tetrahydrobiopterin 0.03% 0.02% 0.04%
Tetrahydropterin 0.03% ND 0.09% Individual Unidentified ND 0.04% ND
Total Unidentified ND 0.04% ND Total 0.10% 0.14% 0.30% ND = Not
Detected RRT = Relative Retention Time
Example 6
Clinical Evaluation of BH4 Capsules
[0244] In designing a clinical evaluation of
(6R)-L-erythro-tetrahydrobiopterin dihydrochloride, an important
consideration is that BH4 is an essential co-factor for two enzymes
primarily located in the central nervous system (CNS), tyrosine and
tryptophan hydroxylases, and the dose of BH4 needed for normal
neurotransmitter metabolism in the CNS is significantly higher than
the dose needed to improve PAH activity in the liver.
[0245] The clinical evaluation comprises two clinical studies. In
both studies, BH4 dihydrochloride is administered once daily to
achieve higher peak concentrations and consequently improved CNS
penetration.
[0246] A first study evaluates the relative bioavailability of BH4
dihydrochloride administered as a capsule in fasted conditions and
after a meal in healthy subjects. Ascending doses of BH4
dihydrochloride up to 40 mg/kg/day are evaluated and drug levels in
cerebrospinal fluid (CSF) are measured. Administration of higher
doses up to 40 mg/kg/day as a single dose is expected to achieve
higher peak levels of BH4 in CSF, provide availability of BH4 in
CSF, and improve penetration of BH4 into the CNS. Measurement of
BH4 levels in CSF is expected to be indicative of BH4 availability
in brain tissues.
[0247] A second study evaluates the safety and efficacy of BH4
dihydrochloride in subjects with hyperphenylalaninemia due to BH4
deficiency. The subjects continue to receive the maximum dose of
BH4 dihydrochloride tolerated in the first study for a total of 3
months. The primary endpoint for the second study is a measure of
blood phenylalanine control. Moreover, other CSF parameters and
neurological outcomes are evaluated. For example, serotonin and
folate metabolism can be monitored by assessing 5-HIAA and 5-MTHF
levels in the CSF. Further, because dopamine inhibits the secretion
of prolactin and hyperprolactinemia has been documented in patients
with BH4 deficiency, change in prolactin concentrations can
function as a useful indicator of dopamine synthesis and content in
the brain.
Example 7
Dry Process for Making Sachet Dosage Forms
[0248] The active ingredient, (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride or a BH4-related compound, and all the excipients
were separately pre-screened through an appropriate size mesh
(e.g., #20 mesh screen). A powder blend for sachets was prepared by
adding one-half of the preweighed sweetener to a suitable blender
(e.g., V-blender), adding the preweighed BH4 or a BH4-related
compound to the blender, adding the preweighed flavor enhancer to
the blender, and adding the remaining sweetener to the blender. The
dry mixture was blended until the it was adequately mixed. A
portion of the first mixture was then mixed with a preweighed
amount of acesulfame potassium or sucralose, a flavoring agent, and
ascorbic acid in a separate blender. The second mixture was passed
through a suitable sieve (e.g., #20 mesh sieve) and then added to
the remainder of the first mixture in the first blender and mixed
until the blend was homogonous. The desired amount of the final
powder blend was filled into sachets (e.g., single or double
chamber sachets).
[0249] The sachets can be flushed with inert gas. The sachets can
be hermetically sealed. The sachets can include a desiccant. The
sachets may be further packaged in a Mylar pouch. The Mylar pouch
may contain a desiccant.
Example 8
Sachet Dosage Forms
[0250] Certain embodiments of the sachet dosage forms of the
present disclosure are illustrated in Tables 14, 16, and 17. The
sapropterin dihydrochloride in all seven sachet examples in
comparison Table 12 was in the form of polymorph B. Table 12 gives
examples of formulations that comprise an amount of BH4
dihydrochloride of about 15% and between 75-80% mannitol, about
0-1% sucralose, about 1.5% flavoring agent, between 4.5-7%
potassium citrate or potassium sodium tartrate, and about 1%
ascorbic acid fine powder. In a specific embodiment, the flavoring
agent is strawberry, orange on a sucrose substrate, orange on a
mannitol substrate, or grape. In another specific embodiment, the
blend also consists of about 5% potassium citrate.
[0251] Certain embodiments of the stability of the dosage forms
from Table 12 are provided in Table 15. Table 15 presents stability
data on compositions F, C1, and C2 from Table 12. Stability under
different storage conditions were assessed and the potency of the
active BH4 dihydrochloride is presented.
[0252] In an additional embodiment, the pharmaceutical formulation
in the stable sachet dosage forms comprise an amount of BH4
dihydrochloride of about 15.1% BH4 dihydrochloride, 75.3% mannitol,
1.5% orange flavor on a sucrose base, 0.8% sucralose, 4.8%
potassium citrate, and 0.8% ascorbic acid fine powder (Table
16).
TABLE-US-00015 TABLE 14 Examples of BH4 Dihydrochloride Dry blend
Powder Formulations Percent (weight/weight) Ingredient A B C1 C2 D
E F Sapropterin 15.6 15.1 15.3 15.3 15.1 15.1 15.1 dihydrochloride
Mannitol 77.9 35.0 76.7 76.7 75.2 -- 75.2 Sorbitol -- -- -- -- --
75.2 -- Xylitol -- 40.8 -- -- -- -- -- Acesulfame -- 0.2 -- --
potassium Sucralose 0.8 -- 0.8 0.8 0.8 0.8 0.8 Strawberry flavor --
1.5 -- -- -- 1.5 Orange flavor on -- -- 1.5 -- -- -- -- sucrose
substrate Orange flavor on -- -- -- 1.5 -- -- -- mannitol substrate
Grape flavor -- 1.5 1.5 -- Potassium Citrate 4.9 -- 4.9 4.9 -- --
Potassium sodium -- 6.6 -- -- 6.6 6.6 6.6 tartrate Ascorbic Acid
0.8 0.8 0.8 0.8 0.8 0.8 0.8 Fine powder -- -- -- -- -- -- -- Total
(g) 100.0 100.0 100.0 100.0 100.0 100.0 100.0
[0253] In an additional embodiment, the pharmaceutical formulation
in the stable sachet dosage forms comprise an amount of BH4
dihydrochloride of about 15.3% BH4 dihydrochloride, 76.7% mannitol,
1.5% orange flavor on a mannitol base, 0.8% sucralose, 4.8%
potassium citrate, and 0.8% ascorbic acid fine powder (Table
16).
[0254] In another embodiment, the pharmaceutical formulation in the
stable sachet dosage forms comprise a total amount of 0.835 g dry
powder blend with the amount of BH4 dihydrochloride about 23.9% of
the weight or 0.2 g (Table 17).
TABLE-US-00016 TABLE 16 Examples of BH4 Dihydrochloride Dry blend
Powder Formulations Example 1 Example 2 Ingredient Function % w/w
BH4 Active 15.1 15.3 Mannitol Sweetener 75.3 76.7 Orange Flavor
(Sucrose base) Flavor 1.5 -- Orange Flavor (Mannitol base) Flavor
-- 1.5 Sucralose Sweetener 0.8 0.8 Potassium Citrate Flavor 4.8 4.8
Enhancer Ascorbic Acid Fine Flavor 0.8 0.8 Enhancer Total 100%
100%
TABLE-US-00017 TABLE 17 Examples of Sachet Dosage Formulations of
BH4 Dihydrochloride Formulation C Formulation D Formulation E
Ingredient g/sachet % g/sachet % g/sachet % Sapropterin HCl 0.2000
23.95 0.2000 23.95 0.2000 23.95 Mannitol 0.3400 40.72 0.3381 40.49
0.3369 40.34 Sucralose 0.0100 1.20 0.0119 1.42 0.0131 1.57
Potassium Citrate 0.0650 7.78 0.0650 7.78 0.0650 7.78 Ascorbic Acid
0.0100 1.20 0.0100 1.20 0.0100 1.20 Citric acid anhydrous 0.1500
17.96 0.1500 17.96 0.1500 17.96 Sodium citrate dihydrate 0.0600
7.19 0.0600 7.19 0.0600 7.19 Total 0.8350 100.00 0.8350 100.00
0.8350 100.00
Example 9
Stability of Various Sachet Dosage Forms
[0255] Certain embodiments of the sachet dosage forms of the
present disclosure are illustrated in Table 18, with a comparison
of the stability of different BH4 or BH4-related compounds packaged
in foil pouches.
TABLE-US-00018 TABLE 18 Stability of BH4 Dihydrochloride Sachet
Packaged in Foil Pouches T = 1 Month T = 3 Month Lot 11434-50 Lot
11434-51 Lot 11434-50 Lot 11434-51 Orange Orange Orange Orange
40.degree. C./75% RH (Sucrose (Mannitol (Sucrose (Mannitol Sample
base) base) base) base) Biopterin (RRT = .5) % 0.029 0.026 0.106
0.138 BH2 (RRT = .6) % 0.132 0.123 0.162 0.304 R-THBL (RRT = .79) %
0.038 0.082 0.093 0.154 S-THBL (RRT = .88) % ND ND ND 0.057 BH4 %
91.75 97.74 48.48 96.37 S-BH4 (RRT = 1.2) % ND ND 0.009 0.010 THP
(RRT = 1.4) % ND ND 0.057 0.105 Unknown Impurity (RRT = 1.4) % ND
ND 0.012 0.036 Unknown Impurity (RRT = .54) % ND ND 0.030 0.068
Unknown Impurity (RRT = .58) % ND ND 0.018 0.013 Unknown Impurity
(RRT = .72) % 0.062 ND 0.079 0.018 Unknown Impurity (RRT = .81) %
ND ND 0.064 ND Total Unknown Impurity 0.062 ND 0.203 0.135 Total
Impurity 0.261 0.231 0.629 0.903 ND = Not Detected
Example 10
Sachet Dosage Form Data without Flavoring
[0256] Certain embodiments of the sachet dosage forms of the
present disclosure are illustrated in Table 19, wherein the sachet
formulation may consist of a BH4 or BH4-related compound, a
sweetener, and flavor enhancers without a flavoring agent.
[0257] It is understood that every embodiment described herein can
optionally be combined with any one or more of the other
embodiments described herein.
[0258] Every patent literature and every non-patent literature
cited herein are incorporated herein by reference in their
entirety.
TABLE-US-00019 TABLE 19 Sachet dosage formulation without flavoring
agents Ingredient g/sachet % Sapropterin HCl 0.2 32 Mannitol 0.35
56 Potassium 0.065 10.4 Citrate Ascorbic Acid 0.01 1.6 TOTAL 0.625
100
[0259] Numerous modifications and variations to the disclosure, as
set forth in the embodiments and illustrative examples described
herein, are expected to occur to those skilled in the art.
Consequently, only such limitations as appear in the accompanying
claims should be placed on the disclosure.
Example 11
Sachet Dosage Form Containing 200 mg BH4 Dihydrochloride
[0260] Table 20 describes the formulation of a stable sachet dosage
form comprising 200 mg (6R)-L-erythro-tetrahydrobiopterin
dihydrochloride in polymorphic form B. This sachet dosage form was
prepared in a manner as provided in the Detailed Description.
TABLE-US-00020 TABLE 20 Sachet dosage formulation containing 200 mg
BH4 Dihydrochloride Ingredient mg/sachet % Sapropterin 200 32 2HCl
Sucralose 11.9 1.9 micronized Potassium citrate 65 10.4 monohydrate
Ascorbic acid 10 1.6 fine powder TOTAL 625 100
[0261] The examples set forth above are provided to give those of
ordinary skill in the art with a complete disclosure and
description of how to make and use the claimed embodiments, and are
not intended to limit the scope of what is disclosed herein.
Modifications that are obvious to persons of skill in the art are
intended to be within the scope of the following claims. All
publications, patents, and patent applications cited in this
specification are incorporated herein by reference as if each such
publication, patent or patent application were specifically and
individually indicated to be incorporated herein by reference.
* * * * *