U.S. patent application number 14/442413 was filed with the patent office on 2016-03-10 for production of salts of 4-hydroxybutyrate using biobased raw materials.
The applicant listed for this patent is METABOLIX, INC.. Invention is credited to Joseph Gredder, Christopher Mirley, Sung Min Park, Oliver Peoples, Derek Samuelson, Max Senechal.
Application Number | 20160068463 14/442413 |
Document ID | / |
Family ID | 49725330 |
Filed Date | 2016-03-10 |
United States Patent
Application |
20160068463 |
Kind Code |
A1 |
Peoples; Oliver ; et
al. |
March 10, 2016 |
PRODUCTION OF SALTS OF 4-HYDROXYBUTYRATE USING BIOBASED RAW
MATERIALS
Abstract
Gamma-butyrolactone ("GBL") and Gamma-hydroxybutyrate ("GHB")
having a unique carbon footprint as defined by the percent modern
carbon (pmc) are described herein. The percent modern carbon can be
controlled by varying the amounts of biobased, renewable starting
materials and petroleum-based starting materials to prepare GBL or
GHB having a defined pmc or by preparing mixtures of GBL or GHB
prepared from biobased renewable starting materials and GBL or GHB
prepared from petroleum-based starting materials.
Inventors: |
Peoples; Oliver; (Arlington,
MA) ; Samuelson; Derek; (Somerville, MA) ;
Senechal; Max; (Arlington, MA) ; Park; Sung Min;
(Arlington, MA) ; Gredder; Joseph; (Cambridge,
MA) ; Mirley; Christopher; (Winthrop, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
METABOLIX, INC. |
Cambridge |
MA |
US |
|
|
Family ID: |
49725330 |
Appl. No.: |
14/442413 |
Filed: |
October 21, 2013 |
PCT Filed: |
October 21, 2013 |
PCT NO: |
PCT/US2013/065916 |
371 Date: |
May 13, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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61834974 |
Jun 14, 2013 |
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61823518 |
May 15, 2013 |
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61772602 |
Mar 5, 2013 |
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61726294 |
Nov 14, 2012 |
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Current U.S.
Class: |
424/474 ;
435/146; 514/557; 514/772.3; 528/361; 560/187; 562/579 |
Current CPC
Class: |
A61K 9/28 20130101; C08G
63/06 20130101; C07D 307/06 20130101; A61L 17/105 20130101; C07D
307/33 20130101; C07C 59/01 20130101; A61K 47/34 20130101; C07C
51/41 20130101 |
International
Class: |
C07C 59/01 20060101
C07C059/01; A61L 17/10 20060101 A61L017/10; C07C 51/41 20060101
C07C051/41; A61K 47/34 20060101 A61K047/34; C08G 63/06 20060101
C08G063/06; A61K 9/28 20060101 A61K009/28 |
Claims
1. Gamma-hydroxybutyrate, deuterated gamma-hydroxybutyrate, or a
pharmaceutically acceptable salt thereof, wherein a percentage of
the carbon in the gamma-hydroxybutyrate, deuterated
gamma-hydroxybutyrate, or salt thereof is modern carbon and the
remaining percentage of carbon is fossil-carbon, wherein the ratio
of modern carbon to fossil-carbon provides a unique carbon
footprint which identifies the source of the
gamma-hydroxybutyrate.
2. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 1, wherein the percent modern carbon is about 0.1, 5, 10, 15,
20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or
95%.
3. (canceled)
4. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 1, wherein the gamma-hydroxybutyrate is in the form of an
oligomer or polymer of gamma-hydroxybutyrate.
5. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 1, wherein the gamma-hydroxybutyrate is in the form of an
alkali metal salt.
6. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 5, wherein the salt is a salt of a Group I metal, such as
sodium or potassium.
7. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 5, wherein the salt is a salt of a Group II metal, such as
calcium or magnesium.
8. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 1, wherein the gamma-hydroxybutyrate is partially or wholly
deuterated.
9. The gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of
claim 1, wherein the gamma-hydroxybutyrate is partially or wholly
fluorinated.
10. A pharmaceutical composition comprising the
gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate of claim
1 and one or more pharmaceutically acceptable carriers.
11. The composition of claim 10, wherein the composition is
formulated for enteral administration.
12. The composition of claim 11 comprising a solid dosage form
which releases 90% by weight of the gamma-hydroxybutyrate or
deuterated gamma-hydroxybutyrate within one hour as measured in
de-ionized water using USP Apparatus 2 at 37.degree.
C..+-.2.degree. C. with paddles at 50 rpm.
13. The composition of claim 12, wherein the dosage form is a
tablet.
14. The composition of claim 11 comprising a solid dosage form
which releases 99% by weight or more of the gamma-hydroxybutyrate
or deuterated gamma-hydroxybutyrate over a time period of six to
eight hours as measured in de-ionized water using USP Apparatus 2
at 37.degree. C..+-.2.degree. C. with paddles at 50 rpm.
15. The composition of claim 14, wherein the dosage form is a
tablet.
16. The composition of claim 13 further comprising an outer coating
on the solid tablet which releases 90% by weight of the
gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate in the
outer coating within one hour.
17. The composition of claim 10, wherein the composition is
formulated for parenteral administration.
18. The composition of claim 17, wherein the gamma-hydroxybutyrate
or deuterated gamma-hydroxybutyrate is formulated as a solution
having a pH from about 3 to about 10.5, preferably from about 6 to
about 8.5, more preferably from about 6 to about 7.5.
19. The composition of claim 18, wherein the concentration of the
gamma-hydroxybutyrate or deuterated gamma-hydroxybutyrate in the
solution is from about 150 mg/ml to about 550 mg/ml.
20.-27. (canceled)
28. A method of tracing gamma-hydroxybutyrate or deuterated
gamma-hydroxy butyrate, the method comprising preparing
gamma-hydroxybutyrate or deuterated gamma-hydroxy butyrate having a
defined ratio of modern carbon to fossil carbon, wherein the ratio
of modern carbon to fossil carbon provides a unique carbon
footprint which identifies the source of the gamma-hydroxybutyrate
or deuterated gamma-hydroxy butyrate.
29. A method of treating cataplexy and/or excessive daytime
sleepiness narcolepsy, the method comprising administering an
effective amount of the gamma-hydroxybutyrate or deuterated
gamma-hydroxy butyrate of claim 1.
30. (canceled)
31. A composition comprising deuterated oligomers of
gamma-butyrolactone in combination with deuterated
poly(4-hydroxybutyrate) and deuterated gamma-butyrolactone monomer,
wherein a percentage of the carbon in the compound or compounds is
modern carbon and the remaining percentage of carbon is
fossil-carbon, wherein the ratio of modern carbon to fossil-carbon
provides a unique carbon footprint which identifies the source of
the compound or compounds.
32.-34. (canceled)
35. A deuterated poly(4-hydroxybutyrate), wherein a percentage of
the carbon in the deuterated poly(4-hydroxybutyrate) is modern
carbon and the remaining percentage of carbon is fossil-carbon,
wherein the ratio of modern carbon to fossil-carbon provides a
unique carbon footprint which identifies the source of the
deuterated poly(4-hydroxybutyrate).
36. A method of production of a deuterated poly(4-hydroxybutyrate)
(P4HB), comprising: providing a genetically modified organism
designed to produce P4HB; and growing the genetically modified
organism on a growth media comprising one or more of deuterated
water and deuterated glucose under the conditions and for the
duration sufficient to produce P4HB, wherein P4HB is enriched for
deuterium.
37. A fiber comprising a deuterated poly(4-hydroxybutyrate).
38. A mesh comprising the fiber of claim 37.
39. A method of manufacturing a deuterated fiber, comprising:
providing a genetically modified organism designed to produce P4H;
growing the genetically modified organism on a growth media
comprising one or more of deuterated water and deuterated glucose
under the conditions and for the duration sufficient to produce
homo- or copolymer of 4-hydroxybutyrate (P4HB), wherein P4HB is
enriched for deuterium (deuterated P4HB); and producing a fiber
comprising the deuterated P4HB.
40. A suture comprising the fiber of claim 37.
41. A deuterated poly(4-hydroxybutyrate).
42. A method of production of a deuterated poly(4-hydroxybutyrate)
(P4HB), comprising: providing a genetically modified organism
designed to produce P4HB; and growing the genetically modified
organism on a growth media comprising one or more sources of
deuterium under the conditions and for the duration sufficient to
produce P4HB, wherein P4HB is enriched for deuterium.
43. A method of manufacturing a deuterated fiber, comprising:
providing a genetically modified organism designed to produce
poly(4-hydroxybutyrate) P4HB; growing the genetically modified
organism on a growth media comprising one or more of sources of
deuterium under the conditions and for the duration sufficient to
produce P4HB, wherein P4HB is enriched for deuterium (deuterated
P4HB); and producing a fiber comprising the deuterated P4HB.
Description
FIELD OF THE INVENTION
[0001] This invention is in the field of gamma-hydroxybutyrate
having a carbon footprint which can be used to identify the source
of the gamma-hydroxybutyrate, pharmaceutical compositions
containing the traceable gamma-hydroxybutyrate, and methods of use
thereof.
BACKGROUND OF THE INVENTION
[0002] .gamma.-Hydroxybutyric acid (OHB), also known as
4-hydroxybutanoic acid and sodium oxybate (INN), is a naturally
occurring substance found in the human central nervous system, as
well as in wine, beef, small citrus fruits, and almost all animals
in small amounts. GHB is naturally produced in the human body's
cells and is structurally related to the ketone body
beta-hydroxybutyrate.
[0003] HB has been used in medical settings as a general
anesthetic, to treat conditions such as insomnia, clinical
depression, narcolepsy, and alcoholism. GHB as the sodium salt,
known as sodium oxybate, is sold by Jazz Pharmaceuticals under the
name Xyrem to treat cataplexy and excessive daytime sleepiness in
patients with narcolepsy.
[0004] However, GHB is most well known for it abuse potential. GHB
is used illegally as an intoxicant or as a date rape drug. Its
effects have been described anecdotally as comparable with alcohol
and ecstasy use, such as euphoria, disinhibition, enhanced
sensuality and empathogenesis. At higher doses, GHB may induce
nausea, dizziness, drowsiness, agitation, visual disturbances,
depressed breathing, amnesia, unconsciousness, and death. The
effects of GHB can last from 1.5 to 3 hours, or even longer if
large doses have been consumed. Consuming GHB with alcohol is
dangerous as it can lead to vomiting in combination with
unrouseable sleep, a potentially lethal combination. When used as a
recreational drug, GHB may be found as the sodium or potassium
salt, which is a white crystalline powder, or as GHB salt dissolved
in water to form a clear solution. The sodium salt of GHB has a
salty taste. Other salt forms such as calcium GHB and magnesium GHB
have also been reported, but the sodium salt is by far the most
common. Like alcohol and potent benzodiazepines such as Rohypnol
(the trade name of a potent hypnotic benzodiazepine,
flunitrazepam), GHB has been labeled as a date rape drug. The
sodium form of GHB has an extremely salty taste but, as it is
colourless and odorless, it has been described as "very easy to add
to drinks" that mask the flavor. GHB has allegedly been used in
cases of drug-related sexual assault, usually when the victim is
vulnerable due to intoxication with a sedative, generally alcohol.
It is difficult to establish how often GHB is used to facilitate
rape as it is difficult to detect in a urine sample after a day,
and many victims may not recall the rape until some time after
this, although GHB can be detected in hair.
[0005] There have been several high profile cases of GHB as a date
rape drug that received national attention in the United States. In
early 1999 a 15 year old girl, Samantha Reid of Rockwood, Mich.,
died from GHB poisoning. Reid's death inspired the legislation
titled the "Hillory J. Farias and Samantha Reid Date-Rape Drug
Prohibition Act of 2000." This is the law that made GHB a schedule
1 controlled substance.
[0006] GHB has also been used illegally to boost or enhance
athletic performance. GHB has been shown to elevate human growth
hormone in vivo. The growth hormone elevating effects of GHB are
mediated through muscarinic acetylcholine receptors and can be
prevented by prior administration of pirenzepine, a muscarinic
acetylcholine receptor blocking agent.
[0007] GHB can be easily manufactured at home with very little
knowledge of chemistry, as it only involves the mixing of its two
precursors, GBL and an alkali hydroxide (such as sodium hydroxide)
to form the resulting GHB salt. Due to the ease of manufacture and
the availability of its precursors, its production is not done in
relatively few illicit laboratories like most other synthetic
drugs, but in private homes by low level producers instead.
[0008] In view of the high abuse potential and ease of manufacture
described above, GHB is categorized as an illegal drug in many
countries. It is currently regulated in Australia and New Zealand,
Canada, most of Europe and in the United States. Therefore, there
exists a need to trace the origin or source of GHB so that local,
state, and/or federal law enforcement agencies and/or health
departments can determine whether the GHB that is used illegally is
being produced by a legitimate, approved source or an illegal
manufacturer. The ability to produce GHB having a unique
fingerprint may allow law enforcement to readily determine the
source of a particular sample of GHB.
[0009] Therefore, it is an object of the invention to provide
traceable gamma-hydroxybutyrate, compositions containing the same,
and methods of making and using thereof.
SUMMARY OF THE INVENTION
[0010] Gamma-butyrolactone ("GBL") and Gamma-hydroxybutyrate
("GHB") having a unique carbon footprint as defined by the percent
modern carbon (pmc) are described herein. The percent modern carbon
can be controlled by varying the amounts of biobased, renewable
starting materials and petroleum-based starting materials to
prepare GBL or GHB having a defined pmc or by preparing mixtures of
GBL or GHB prepared from biobased renewable starting materials and
GBL or GHB prepared from petroleum-based starting materials.
[0011] In one embodiment, gamma-hydroxybutyrate has a pmc of at
least about 1% to at least about 99%, for example about 5, 10, 15,
20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95%.
In particular embodiments, gamma-hydroxybutyrate has a pmc of at
least about 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93,
94, 95, 95, 97, 98, or 99. In particular embodiments,
gamma-hydroxybutyrate has a pmc of at least about 99%. In other
embodiments, gamma-hydroxybutyrate can be in the form of a mixture
of gamma-hydroxybutyrate prepared from biobased, renewable raw
materials and gamma-hydroxybutyrate prepared from petroleum-based
materials, wherein the ratio of the two is controlled to provide a
unique carbon footprint. The pmc of the mixture can be as described
above.
[0012] Gamma-hydroxybutyrate can be formulated as the free
carboxylic acid, one or more pharmaceutically acceptable
base-addition salts, oligomers of gamma-hydroxybutyrate, and
pharmaceutically salts of the oligomers. Gamma-hydroxybutyrate and
its oligomers, polymers or their salts (e.g. sodium oxybate) can
also be modified by substitution of all or some of their hydrogen
atoms with deuterium or fluorine atoms. Deuterated
gamma-hydroxybutyrate is referred to as DGHB and deuterated
gamma-butyrolactone is referred to DGBL. Drug molecules modified in
this way reportedly improve either the metabolism of a drug (as is
the case with deuterium isotopologues) or the binding affinity of
the drug to target receptors (as is the case with fluorine-modified
drugs).
[0013] Gamma-butyrolactone or deuterated gamma-butryolactone can be
converted to gamma-hydroxybutyrate or deuterated
gamma-hydrobutyrate by saponification (e.g., base-catalyzed ring
opening) of the lactone ring including continuous methods for
effecting the ring opening of gamma-butyrolactone or deuterated
gammo-butyrolactone to form gamma-hydroxybutyrate or deuterated
gamma-hydrobutyrate. Other procedures for producing
gamma-hydroxybutyrate or deuterated gamma-hydrobutyrate include the
partial hydrogenation of succinic acid or deuterated forms thereof
having a unique carbon footprint and partial oxidation of
butanediol or deuterated forms thereof have a unique carbon
footprint.
[0014] In one embodiment, biobased gamma-butyrolactone or
deuterated gamma-butyrolactone having a unique carbon footprint is
produced from the conversion to biobased GHB or DGHB having a
unique carbon footprint by pyrolysis of poly(4-hydroxybutyrate) or
deuterated poly(4-hydroxybutyrate).
[0015] P4HB or deuterated forms thereof ("DP4HB") can be produced
from a variety of biobased, renewable raw materials, such as
glucose or deuterated glucose syrup using fermentation methods.
P4HB or DP4HB can also be prepared from a mixture of biobased,
renewable raw materials and petroleum-based raw materials using the
same fermentation procedures. In some embodiments, deuterated
glucose and/or deuterated water can be used as the deuterium
source.
[0016] P4HB or DP4HB can be pyrolyzed in the presence of
Ca(OH).sub.2 to produce GBL or DGBL, which can be saponified to
form GHB or DGHB. P4HB or DP4HB can also be converted to GHB or
DGHB by dissolving purified P4HB or DP4HB in an organic solvent,
such as tetrahydrofiran (THF), and reacted with a base, such as
sodium methoxide, to convert P4HB or DP4HB directly to GHB or DGHB.
The same procedure can also be used to prepare 4HB or D4HB
oligomers of a desired molecular weight. Biobased GBL or DGBL or a
mixture of biobased GBL or DGBL and petroleum-based GBL or DGBL can
be converted to GHB or DGHB by reacting GBL or DGBL with a base,
such as sodium hydroxide, to form the sodium salt of
gamma-hydroxybutyric acid, sodium gamma-hydroxybutyrate or
deuterated gamma-hydrobutyrate.
[0017] GBL or GBH or deuterated forms thereof having a unique
carbon footprint can be prepared from succinic acid or deuterated
forms thereof. Succinic acid having a particular carbon footprint
can be prepared by fermentation of microbial biomass, isolation of
the succinic acid, and catalytic hydrogenation of succinic acid to
form GHB.
[0018] GHB having a unique footprint can also be prepared from
1,4-butanediol or deuterated forms thereof having the unique carbon
footprint. 1,4-butanediol having a particular carbon footprint can
be prepared by fermentation of microbial biomass, isolation of the
1,4-butanediol, and catalytic oxidation of 1,4-butane diol to form
GHB.
[0019] The compounds described herein can be formulated for
enteral, parenteral, topical, or pulmonary administration. The
compounds can be combined with one or more pharmaceutically
acceptable carriers and/or excipients that are considered safe and
effective and may be administered to an individual without causing
undesirable biological side effects or unwanted interactions. The
carrier is all components present in the pharmaceutical formulation
other than the active ingredient or ingredients.
[0020] By producing GBL or GHB or deuterated forms thereof having a
unique carbon footprint as defined by the pmc, law enforcement
agencies can identify the source of GBL or GHB as well as track
shipments of the materials from site of manufacture to end user.
The footprint can be used to confirm whether a sample was prepared
by a legitimate manufacturer or an illegal drug lab.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a flow chart showing the steps for the synthesis
of deuterated P4HB using D.sub.2O or deuterated glucose as the
deuterium source.
DETAILED DESCRIPTION OF THE INVENTION
I. Definitions
[0022] "Biobased content", as used herein, refers to the amount of
biomass-derived carbon in a sample of gamma-hydroxybutyrate
("GHB"). The biobased content can be determined using techniques
known in the art, such as ASTM-D6888. The biobased content can be
determined by deriving the ratio of the amount of .sup.14C in an
unknown sample to that of a modern reference standard. This ratio
is calculated as a percentage with the units "pmc" (percent modern
carbon). If the material being analyzed is a mixture of present day
radiocarbon and fossil carbon (containing no radio carbon), then
the pmc value correlates directly to the amount of biomass derived
carbon in the sample.
[0023] The modern reference standard used in radiocarbon dating is
a NIST (National Institute of Standards and Technology) standard
with a known radiocarbon content equivalent approximately to the
year AD 1950. AD 1950 was chosen since it represented a time prior
to thermo-nuclear weapons testing which introduced large amounts of
excess radiocarbon into the atmosphere with each explosion (termed
"bomb carbon"). For an archaeologist or geologist using radiocarbon
dates, AD 1950 equals "zero years old". It also represents 100
pMC.
[0024] "Bomb carbon" in the atmosphere reached almost twice normal
levels in 1963 at the peak of testing and prior to the treaty
halting testing. Its distribution within the atmosphere has been
approximated since its appearance, showing values that are greater
than 100 pMC for plants and animals living since AD 1950. It has
gradually decreased over time with today's value being near 105
pMC. This means that a fresh biomass material such as corn, sugar
cane or soybeans would give a radiocarbon signature near 105 pMC.
Combining fossil carbon with present day carbon into a material
will result in a dilution of the present day pMC content. By
presuming .about.105 pMC represents present day biomass materials
and 0 pMC represents petroleum derivatives, the measured
pMC value for that material will reflect the proportions of the two
component types. For example, a material derived 100% from present
day soybeans would give a radiocarbon signature near 105 pMC. But
if it was diluted with 50% petroleum carbon, it would give a
radiocarbon signature near 53 pMC.
[0025] The "biobased content" of a material is reported as a
percent value relating total renewable organic carbon to total
organic carbon. The final result is calculated by multiplying the
pMC value measured for the material by 0.95 (to adjust for bomb
carbon effect). The final value is cited as the MEAN BIOBASED
RESULT and assumes all the components within the analyzed material
were either present day living (within the last decade) or fossil
in origin.
[0026] "Effective amount" as generally used herein refers to an
amount, or dose, within the range normally given or prescribed to
demonstrate an effect, e.g., in vitro or in vivo. The range of an
effective amount may vary from individual to individual; however,
the optimal dose is readily determinable by those of skill in the
art depending upon the use. Such ranges are well established in
routine clinical practice and will thus be readily determinable to
those of skill in the art. Doses may be measured by total amount
given (e.g. per dose or per day) or by concentration. Doses of
0.01, 0.05, 0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25,
30, 40, 50, 100, 500 and 1000 mg/kg/day may be appropriate for
treatment.
[0027] "Pharmaceutically acceptable" as generally used herein
refers to those compounds, materials, compositions, and/or dosage
forms which are, within the scope of sound medical judgment,
suitable for use in contact with the tissues of human beings and
animals without excessive toxicity, irritation, allergic response,
or other problems or complications commensurate with a reasonable
benefit/risk ratio.
II. Gamma-Hydroxybutyrate
[0028] Gamma-hydroxybutyrate has the following chemical
structure:
##STR00001##
[0029] Gamma-hydroxybutyrate or deuterated forms thereof produced
from biobased raw materials, alone or in combination with
fossil-fuel derived or petroleum-based raw materials are described
herein. By varying the amounts of biobased raw material and
fossil-fuel derived material, one can produce gamma-hydroxybutyrate
have a unique carbon footprint or signature which can be used as a
means for identifying the source of the gamma-hydroxybutyrate
(i.e., the manufacturer) as well as tracking its shipping and
usage. This footprint is derived from the ratio of modern carbon,
which is incorporated from the biobased raw materials to fossil
carbon, which is derived from petroleum-based raw materials and is
express as the percent modern carbon or pmc.
[0030] In one embodiment, gamma-hydroxybutyrate has a pmc of at
least about 1% to at least about 99%, for example about 5, 10, 15,
20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95%.
In particular embodiments, gamma-hydroxybutyrate has a pmc of at
least about 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 93,
94, 95, 95, 97, 98, or 99. In particular embodiments,
gamma-hydroxybutyrate has a pmc of at least about 99%. In other
embodiments, gamma-hydroxybutyrate can be in the form of a mixture
of gamma-hydroxybutyrate prepared from biobased, renewable raw
materials and gamma-hydroxybutyrate prepared from petroleum-based
materials, wherein the ratio of the two is controlled to provide a
unique carbon footprint. The pmc of the mixture can be as described
above.
[0031] Gamma-hydroxybutyrate can be formulated as the free
carboxylic acid, one or more pharmaceutically acceptable
base-addition salts, oligomers of gamma-hydroxybutyrate, and
pharmaceutically salts of the oligomers.
[0032] "Pharmaceutically acceptable salts" as generally used herein
refer to derivatives of the disclosed compounds wherein the parent
compound is modified by making the base salt thereof. Examples of
pharmaceutically acceptable salts include, but are not limited to,
alkali or organic salts of acidic residues such as carboxylic
acids. Suitable salts include, but are not limited to, Group I
metals, such as sodium and potassium, and Group II metals, such as
magnesium and calcium.
[0033] The gamma-hydroxybutyrate can also be formulated an oligomer
or polymer of gamma-hydroxybutyrate. "Oligomer", as used herein,
generally refers to polymers having 2-10 repeat units, while
"polymer" as used herein, generally refers to polymers having at
more than 10 repeat units. The preferred compositions may contain
GHB alone, as in a homopolymer (or oligomer) of
gamma-hydroxybutyrate, or may comprise GHB in a polymer or oligomer
together with other monomers. For example, GHB may be copolymerized
with .beta.-hydroxybutyrate, as in
poly-.beta.-hydroxybutyrate-co-.gamma.-hydroxybutyrate, or
copolymerized with two or more different monomers, including other
hydroxyalkanoates or hydroxyacids. Examples of monomers which can
be incorporated into GHB polymers and oligomers are identified in
Williams, et. al., Int. J. Biol. Macromol., 25:111-21 (1999).
[0034] In addition to linear oligomers comprising GHB, cyclic
oligomers comprising GHB may be especially useful for delivery of
OHB in vivo. These may be prepared, for example, according to
procedures described in Muller & Seebach, Angew. Chem. Int. Ed
Engl. 32:477-502 (1993).
[0035] In a further embodiment, polymers and oligomers may be
prepared that do not contain GHB, but break down in vivo to GHB. An
example of such a polymer is the bioerodible polyorthoester
described in Sendelbeck & Girdis, Drug Metabolism &
Disposition, 1:291-95 (1985).
[0036] The oligomers and polymers can be formulated as a salt of
the oligomer or polymer or can be virtually or completely salt
free. The oligomers and/or polymers can deliver GHB with a range of
different and desirable pharmacokinetics. This includes prolonged
release, steady state release, and controlled dosages, both low and
high.
[0037] Gamma-hydroxybutyrate and/or oligomers and/or polymers
thereof and/or deuterated forms thereof can be formulated for
controlled release, such as immediate release, extended release,
delayed release, pulsatile release, or combinations thereof. In
some embodiments, the molecular weight range of the oligomer or
polymer is from about 500 Daltons to about 50,000 Dalton,
preferably from about 500 Dalton to about 25,000 Daltons, more
preferably from about 500 Daltons to about 15,000 Dalton, most
preferably from about 500 Daltons to about 10,000 Daltons. In some
embodiments, the composition can contain two or more oligomers of
polymers having different weight average molecular weights. For
example, in one embodiment, the composition contains a first
oligomer/polymer having a weight average molecular weight of from
about 500 to about 2,000 Daltons and a second oligomer/polymer
having a weight average molecular weight from about 2,000 to about
10,000 Daltons.
[0038] In other embodiments, the composition can contain oligomers
saturated with a salt of 4HB or GBL such that the dosing of 4HB is
biphasic with a first rapid release followed by a slow release from
the oligomers to achieve a single does when administered at night
(e.g., before bed).
[0039] The use of oligomers and polymer can overcome some
limitations sometimes associated with use of the monomer. For
example, the development of hypernatremia and metabolic alkalosis
has been reported as a result of delivering large doses of GHB when
administered as the sodium salt rather than a free acid, especially
over prolonged periods. It has been reported that these conditions
developed in patients undergoing hemodialysis. The use of oligomers
or polymers of GHB can reduce the amount of sodium ion administered
and therefore avoid the side effects associated with high
concentrations of sodium ion.
[0040] In addition to problems associated with the delivery of the
sodium salt form of GHB, the half-life of GHB is relatively short
(35 minutes, with peak plasma concentration occurring 20-60 minutes
after oral administration), requiring more frequent administration
of GHB to maintain its therapeutic effects. For example, it has
been reported that increasing the dosing of GHB from three times a
day to six times a day was beneficial in the treatment of
alcoholism, particularly for a patient population which did not
respond well to less frequent dosages. Furthermore, in the
treatment of narcoleptic patients, patients were found to benefit
from two, or even three, doses of GHB during the night instead of a
single dose which left patients wide awake before their planned
awakening time (Scharf, Sleep, 21:507-14 (1998)). Also,
oligomers/polymers are not readily dissolved in drinks such as
soda, fruit juices or alcoholic beverages which should reduce abuse
potential.
[0041] In another embodiment, GHB and its oligomers, polymers and
salt forms can be modified by substituting some or all of its
hydrogen atoms with deuterium or fluorine. Complete or partial
substitution of the hydrogen atoms with deuterium in drug molecules
has been shown to positively affect the medicinal properties of
drugs. In particular, the metabolism rates of drug molecules have
been shown to change since C--H bonds are weaker than C-D (the
deuterium atom is twice as heavy), metabolic reactions that rely on
breaking such bonds in their rate-limiting step are slowed, even
though in other chemical and pharmacological aspects there are no
significant differences observed. Several companies are pursuing
this area of research and include Concert Pharmaceuticals, Protia
and Auspex.
[0042] Methods for creating deuterated analogs of organic compounds
are described in the following patents: U.S. Pat. No. 5,221,768
describes how to deuterate hydroxyacids using heavy water
(D.sub.2O) with a rhodium chloride (III) catalyst. The mixture is
then moderately heated under pressure to initiate the
hydrogen-deuterium exchange. U.S. Pat. No. 4,421,865 describes the
use of ion exchange columns to deuterate organic molecules. Patent
Appl. No. US2012/122,952 describes how to produce a deuterated
analog of GHB by first starting with the t-butyl ester of
4-hydroxybutyrate (prepared from succinic acid) and then reacting
it in deuterated methanol in the presence of potassium carbonate.
After hydrogen-deuterium exchange is complete, the compound is
saponified with sodium hydroxide to form deuterated sodium oxybate.
A final method to produce biobased, deuterated GHB is to feed
deuterated glucose (d-glucose) to engineered microbes which produce
P4HB polymer or to carry out the fermentation in D.sub.2O with or
without D-glucose as the feed. The polymer so produced would have
deuterium replacing most if not all of the hydrogen atoms.
Deuterated-GBL (d-GBL) could then be prepared from the polymer as
described previously (through pyrolysis) and the d-GBL converted to
d-sodium oxybate by saponification. Methods for creating
fluorinated analogs of organic compounds are described in
International Patent No. WO2012/214162.
[0043] A. Other Compounds Derived from GBL or Deuterated GBL
[0044] Other compounds having a unique carbon footprint can be
prepared from GBL or deuterated GBL. Compounds having a unique
footprint which can be prepared from GBL or deuterated GBL include,
but are not limited to, poly(4-hydroxybutyrate) or deuterated
poly(4-hydroxybutyrate), 2-pyrrolidone or deuterated 2-pyrrolidone,
1,4-butanediol or deuterated 1,4-butanediol, tetrahydrofuran (THF)
or deuterated THF, n-methylpyrrolidone (NMP) or deuterated NMP,
n-ethylpyrrolidone (NEP) or deuterated NEP, n-vinylpyrrolidone
(NVP) or deuterated (NVP) and polyvinylpyrrolidone (PVP) or
deuterated PVP. These compounds can be used as active agents,
excipients, and/or solvents in pharmaceutical formulations as
described below. In other embodiments, one or more of these
compounds are precursors for one or more active agents. For
example, 2-pyrrolidone is a precursor to the active agents
Cotinine, Doxapram, Piracetam, Povidone, and Ethosuximide.
[0045] B. Derivatives of 4-hydroxybutyrate (4HB)
[0046] Derivatives of 4HB having a unique carbon footprint can also
be prepared. Exemplary derivatives are described, for example, in
U.S. Pat. No. 8,461,197 to Tung, which is incorporated herein by
reference and includes compounds represented by Formulae B, B-II,
B-III, I, II, S-II, and III. Compounds having a unique carbon
footprint may contain no deuterium, one deuterium or more than one
deuterium.
[0047] Deuterated P4HB polymers can also be produced using the
methods described herein and are useful in a range of biomedical
applications including fibers used for sutures and meshes as
described in U.S. Pat. Nos. 6,245,537; 6,610,764; 6,548,569;
6,623,730; 8,034,270; as well as other patents assigned to Tepha,
Inc, all of which are incorporated herein by reference.
III. Formulations
[0048] The compounds described herein can be formulated for
enteral, parenteral, topical, or pulmonary administration. The
compounds can be combined with one or more pharmaceutically
acceptable carriers and/or excipients that are considered safe and
effective and may be administered to an individual without causing
undesirable biological side effects or unwanted interactions. The
carrier is all components present in the pharmaceutical formulation
other than the active ingredient or ingredients.
[0049] A. Parenteral Formulations
[0050] The compounds described herein can be formulated for
parenteral administration. "Parenteral administration", as used
herein, means administration by any method other than through the
digestive tract or non-invasive topical or regional routes. For
example, parenteral administration may include administration to a
patient intravenously, intradermally, intraarterially,
intraperitoneally, intralesionally, intracranially,
intraarticularly, intraprostatically, intrapleurally,
intratracheally, intravitreally, intratumorally, intramuscularly,
subcutaneously, subconjunctivally, intravesicularly,
intrapericardially, intraumbilically, by injection, and by
infusion.
[0051] Parenteral formulations can be prepared as aqueous
compositions using techniques is known in the art. Typically, such
compositions can be prepared as injectable formulations, for
example, solutions or suspensions; solid forms suitable for using
to prepare solutions or suspensions upon the addition of a
reconstitution medium prior to injection; emulsions, such as
water-in-oil (w/o) emulsions, oil-in-water (o/w) emulsions, and
microemulsions thereof, liposomes, or emulsomes.
[0052] The carrier can be a solvent or dispersion medium
containing, for example, water, ethanol, one or more polyols (e.g.,
glycerol, propylene glycol, and liquid polyethylene glycol), oils,
such as vegetable oils (e.g., peanut oil, corn oil, sesame oil,
etc.), and combinations thereof. The proper fluidity can be
maintained, for example, by the use of a coating, such as lecithin,
by the maintenance of the required particle size in the case of
dispersion and/or by the use of surfactants. In many cases, it will
be preferable to include isotonic agents, for example, sugars or
sodium chloride.
[0053] Solutions and dispersions of the active compounds as the
free acid or base or pharmacologically acceptable salts thereof can
be prepared in water or another solvent or dispersing medium
suitably mixed with one or more pharmaceutically acceptable
excipients including, but not limited to, surfactants, dispersants,
emulsifiers, pH modifying agents, viscosity modifying agents, and
combination thereof.
[0054] Suitable surfactants may be anionic, cationic, amphoteric or
nonionic surface active agents. Suitable anionic surfactants
include, but are not limited to, those containing carboxylate,
sulfonate and sulfate ions. Examples of anionic surfactants include
sodium, potassium, ammonium of long chain alkyl sulfonates and
alkyl aryl sulfonates such as sodium dodecylbenzene sulfonate;
dialkyl sodium sulfosuccinates, such as sodium dodecylbenzene
sulfonate; dialkyl sodium sulfosuccinates, such as sodium
bis-(2-ethylthioxyl)-sulfosuccinate; and alkyl sulfates such as
sodium lauryl sulfate. Cationic surfactants include, but are not
limited to, quaternary ammonium compounds such as benzalkonium
chloride, benzethonium chloride, cetrimonium bromide, stearyl
dimethylbenzyl ammonium chloride, polyoxyethylene and coconut
amine. Examples of nonionic surfactants include ethylene glycol
monostearate, propylene glycol myristate, glyceryl monostearate,
glyceryl stearate, polyglyceryl-4-oleate, sorbitan acylate, sucrose
acylate, PEG-150 laurate, PEG-400 monolaurate, polyoxyethylene
monolaurate, polysorbates, polyoxyethylene octylphenylether,
PEG-1000 cetyl ether, polyoxyethylene tridecyl ether, polypropylene
glycol butyl ether, Poloxamer.RTM. 401, stearoyl
monoisopropanolamide, and polyoxyethylene hydrogenated tallow
amide. Examples of amphoteric surfactants include sodium
N-dodecyl-.beta.-alanine, sodium N-lauryl-.beta.-iminodipropionate,
myristoamphoacetate, lauryl betaine and lauryl sulfobetaine.
[0055] The formulation can contain a preservative to prevent the
growth of microorganisms. Suitable preservatives include, but are
not limited to, parabens, chlorobutanol, phenol, sorbic acid, and
thimerosal. The formulation may also contain an antioxidant to
prevent degradation of the active agent(s).
[0056] The formulation is typically buffered to a pH of 3-8 for
parenteral administration upon reconstitution. Suitable buffers
include, but are not limited to, phosphate buffers, acetate
buffers, and citrate buffers.
[0057] Water soluble polymers are often used in formulations for
parenteral administration. Suitable water-soluble polymers include,
but are not limited to, polyvinylpyrrolidone, dextran,
carboxymethylcellulose, and polyethylene glycol.
[0058] Sterile injectable solutions can be prepared by
incorporating the active compounds in the required amount in the
appropriate solvent or dispersion medium with one or more of the
excipients listed above, as required, followed by filtered
sterilization. Generally, dispersions are prepared by incorporating
the various sterilized active ingredients into a sterile vehicle
which contains the basic dispersion medium and the required other
ingredients from those listed above. In the case of sterile powders
for the preparation of sterile injectable solutions, the preferred
methods of preparation are vacuum-drying and freeze-drying
techniques which yield a powder of the active ingredient plus any
additional desired ingredient from a previously sterile-filtered
solution thereof. The powders can be prepared in such a manner that
the particles are porous in nature, which can increase dissolution
of the particles. Methods for making porous particles are well
known in the art.
[0059] Xyrem.RTM., marketed by Jazz Pharmaceuticals, is a solution
of GHB for oral administration. The pH of the solution is carefully
controlled to resist microbial growth and prevent degradation of
GHB into GBL or other substances.
[0060] The pH may be from about 3.0 to about 10.3, or about 3.0,
about 3.1, about 3.2, about 3.3, about 3.4, about 3.5, about 3.6,
about 3.7, about 3.8, about 3.9, about 4.0, about 4.1, about 4.2,
about 4.3, about 4.4, about 4.5, about 4.6, about 4.7, about 4.8,
about 4.9, about 5.0, about 5.1, about 5.2, about 5.3, about 5.4,
about 5.5, about 5.6, about 5.7, about 5.8, about 5.9, about 6.0,
about 6.1, about 6.2, about 6.3, about 6.4, about 6.5, about 6.6,
about 6.7, about 6.8, about 6.9, about 7.0, about 7.1, about 7.2,
about 7.3, about 7.4, about 7.5, about 7.6, about 7.7, about 7.8,
about 7.9, about 8.0, about 8.1, about 8.2, about 8.3, about 8.4,
about 8.5, about 8.6, about 8.7, about 8.8, about 8.9, about 9.0,
about 9.1, about 9.2, about 9.3, about 9.4, about 9.5, about 9.6,
about 9.7, about 9.8, about 9.9, about 10.0, about 10.1, about
10.2, or about 10.3, and all pH values between each of the listed
pH values, of the aqueous media. In some embodiments, the pH is
between about 6 and 8.5, for example, 7.5 to 8.5. This will produce
a GHB composition that is resistant to microbial growth as defined
by the test described herein.
[0061] These pH values will produce compositions resistant to
microbial growth in an aqueous medium if the amount of GHB added,
admixed, or dissolved is from above about 150 mg/ml to about 450
mg/ml, namely, above about 150 mg/ml, about 160 mg/ml, about 170
mg/ml, about 180 mg/ml, about 190 mg/ml, about 200 mg/ml, about 210
mg/ml, about 220 mg/ml, about 230 mg/ml, about 240 mg/ml, about 250
mg/ml, about 260 mg/ml, about 270 mg/ml, about 280 mg/ml, about 290
mg/ml, about 300 mg/ml, about 310 mg/ml, about 320 mg/ml, about 330
mg/ml, about 340 mg/ml, about 350 mg/ml, about 360 mg/ml, about 370
mg/ml, about 380 mg/ml, about 390 mg/ml, about 400 mg/ml, about 410
mg/ml, about 420 mg/ml, about 430 mg/ml, about 440 mg/ml, to about
450 mg/ml, and all amounts of GHB between the values listed.
[0062] The composition may also contain a pH adjusting or buffering
agent. Such agents may be acids, bases, or combinations thereof. In
certain embodiments, the acid may be an organic acid, preferably a
carboxylic acid or alphahydroxy carboxylic acid. In certain other
embodiments, the acid is selected from the group including, but not
limited to, acetic, acetylsalicylic, barbital, barbituric, benzoic,
benzyl penicillin, boric, caffeine, carbonic, citric,
dichloroacetic, ethylenediaminetetra-acetic acid (EDTA), formic,
glycerophosphoric, glycine, lactic, malic, mandelic,
monochloroacetic, oxalic, phenobarbital, phenol, picric, propionic,
saccharin, salicylic, sodium dihydrogen phosphate, succinic,
sulfadiazine, sulfamerazine, sulfapyridine, sulfathiazole,
tartaric, trichloroacetic, and the like, or inorganic acids such as
hydrochloric, nitric, phosphoric or sulfuric, and the like. In a
preferred embodiment, the acid is malic or hydrochloric acid. In
certain other embodiments, the pH adjusting agent may be a base
selected from the group including, but not limited to, acetanilide,
ammonia, apomorphine, atropine, benzocaine, caffeine, calcium
hydroxide, cocaine, codeine, ephedrine, morphine, papaverine,
physostigmine, pilocarpine, potassium bicarbonate, potassium
hydroxide, procaine, quinine, reserpine, sodium bicarbonate, sodium
dihydrogen phosphate, sodium citrate, sodium taitrate, sodium
carbonate, sodium hydroxide, theobromine, thiourea or urea. In
certain other embodiments, the pH adjusting agent may be a mixture
of more than one acid and/or more than one base. In other preferred
embodiments, a weak acid and its conjugate base are used to form a
buffering agent to help stabilize the composition's pH.
[0063] In certain embodiments, the composition may contain one or
more salts. A "salt" is understood herein to mean certain
embodiments to mean a compound formed by the interaction of an acid
and a base, the hydrogen atoms of the acid being replaced by the
positive ion of the base. Various salts, including salts of GHB,
are contemplated, particularly as pH adjusting or buffering agents.
Pharmaceutically acceptable salts, include inorganic acids such as,
for example, hydrochloric or phosphoric acids, or such organic
acids as malic, acetic, oxalic, tartaric, mandelic, and the like.
Salts formed can also be derived from inorganic bases such as, for
example, sodium, potassium, silicates, ammonium, calcium, or ferric
hydroxides, and such organic bases as isopropylamine,
trimethylamine, histidine, procaine and the like. Alkali metal
salts such as lithium, potassium, sodium, and the like may be used,
preferably with an acid to form a pH adjusting agent. Other salts
include ammonium, calcium, magnesium and the like. In one
embodiment, a salt of GHB containing an alkali metal may be
combined with an acid to create a composition that achieves the
desired pH when admixed with an aqueous medium. In another
embodiment, a weak base may be combined with GHB to create a
composition that achieves the desired pH when admixed with an
aqueous solution. Of course, other salts can be formed from
compounds disclosed herein, or as would be known to one of ordinary
skill in the art, and all such salts are contemplated.
[0064] In certain embodiments, excipients may be added to the
composition. An "excipient" as used herein shall mean certain
embodiments which are more or less inert substances added as
diluents or vehicles or to give form or consistency when the remedy
is in a solid form, though they may be contained in liquid form
preparations, e.g. syrups, aromatic powders, honey, and various
elixirs. Excipients may also enhance resistance to microbial
growth, and thus act as a preservative. Such excipients include,
but are not limited to, xylitol, mannitol, lactose, starch,
magnesium stearate, sodium saccharine, cellulose, cellulose
derivatives, magnesium carbonate and the like.
[0065] In certain embodiments, the pharmaceutical composition may
contain a preservative. A "preservative" is understood herein to
mean certain embodiments which are substances added to inhibit
chemical change or microbial action. Such preservatives may
include, but are not limited to, xylitol, sodium benzoate,
methylparaben, propyl gallate BP, sorbic acid, chlorobutanol,
dihydroacetic acid, monothioglycerol, potassium benzoate,
propylparaben, benzoic acid, benzalkonium chloride, alcohol,
benzoic acid, benzalkonium chloride, benzethonium chloride, benzyl
alcohol, butylparaben, cetylpyridinium chloride, ethylenediamine,
ethylparaben, ethyl vanillin, glycerin, hypophosphorus acid,
methylparaben, phenol, phenylethyl alcohol, phenylmercuric nitrate,
propylparaben, sassafras oil, sodium benzoate, sodium propionate,
thimerosal and potassium sorbate. Preferred preservatives may be
selected from the group comprising, but not limited to, xylitol,
sodium benzoate, methylparaben, propylparaben and potassium
sorbate. Xylitol is particularly preferred in certain compositions
of the invention, because it acts as a preservative and a
sweetener, is a caries preventative, is less laxative than other
sweeteners, and is recommended for diabetics.
[0066] In certain embodiments, the pharmaceutical composition may
also contain an antioxidant. An "antioxidant" is understood herein
to mean certain embodiments which are substances that inhibit
oxidation. Such antioxidants include, but are not limited to,
ascorbyl palmitate, butylated hydroxyanisole, butylated
hydroxytoluene, potassium metabisulfite, sodium metabisulfite,
anoxomer and maleic acid BP.
[0067] In certain embodiments, the pharmaceutical composition may
also contain a flavoring agent. A "flavoring agent" is understood
herein to mean certain embodiments which are substances that alters
the flavor of the composition during oral consumption. A type of
"flavoring agent" would be a sweetener. Preferred sweeteners or
flavoring agents would be microbially non-metabolizable. Especially
preferred sweeteners or flavoring agents would be carbohydrates
such as xylitol and sorbitol. Such flavoring agents include, but
are not limited to, acacia syrup, anethole, anise oil, aromatic
elixir, benzaldehyde, benzaldehyde elixir-compound, caraway,
caraway oil, cardamom oil, cardamom seed, cardamom spirit, cardamom
tincture-compound, cherry juice, cherry syrup, cinnamon, cinnamon
oil, cinnamon water, citric acid, citric acid syrup, clove oil,
coca, coca syrup, coriander oil, dextrose, eriodictyon, eriodictyon
fluidextract, eriodictyon syrup aromatic, ethyl acetate, ethyl,
vanillin, fennel oil, ginger, ginger fluidextract, ginger
oleoresin, glucose, glycerin, glycyrrhiza, glycyrrhiza elixir,
glycyrrhiza extract, glycyrrhiza extract-pure, glycyrrhiza
fluidextract, glycyrrhiza syrup, honey, non-alcoholic elixir,
lavender oil, citrus extract or oil, lemon oil, lemon tincture,
mannitol, methyl salicylate, nutmeg oil, orange-bitter-elixir,
orange-bitter-oil, orange flower oil, orange flower water, orange
oil, orange peel-bitter, orange-peel-sweet-tincture, orange
spirit-compound, compound, orange syrup, peppermint, peppermint
oil, peppermint spirit, peppermint water, phenylethyl alcohol,
raspberry juice, raspberry syrup, rosemary oil, rose oil, rose
water, saccharin, saccharin calcium, saccharin sodium, sarsaparilla
syrup, sorbitol solution, spearmint, spearmint oil, sucrose, syrup,
thyme oil, tolu balsam, tolu balsam syrup, vanilla, vanilla
tincture, vanillin or wild cherry syrup.
[0068] Specific formulations are described in U.S. Pat. Nos.
6,780,889; 7,262,219; 7,851,506; and 8,263,650 to Cook et al., the
contents of which are incorporated herein by reference.
[0069] 1. Controlled Release Formulations
[0070] The parenteral formulations described herein can be
formulated for controlled release including immediate release,
delayed release, extended release, pulsatile release, and
combinations thereof.
[0071] i. Nano- and Microparticles
[0072] For parenteral administration, the gamma-hydroxybutyrate,
and optional one or more additional active agents, can be
incorporated into microparticles, nanoparticles, or combinations
thereof that provide controlled release of the
gamma-hydroxybutyrate and/or one or more additional active agents.
In embodiments wherein the formulations contains two or more drugs,
the drugs can be formulated for the same type of controlled release
(e.g., delayed, extended, immediate, or pulsatile) or the drugs can
be independently formulated for different types of release (e.g.,
immediate and delayed, immediate and extended, delayed and
extended, delayed and pulsatile, etc.).
[0073] For example, the gamma-hydroxybutyrate and/or one or more
additional active agents can be incorporated into polymeric
microparticles which provide controlled release of the drug(s).
Release of the drug(s) is controlled by diffusion of the drug(s)
out of the microparticles and/or degradation of the polymeric
particles by hydrolysis and/or enzymatic degradation. Suitable
polymers include ethylcellulose and other natural or synthetic
cellulose derivatives.
[0074] Polymers which are slowly soluble and form a gel in an
aqueous environment, such as hydroxypropyl methylcellulose or
polyethylene oxide may also be suitable as materials for drug
containing microparticles. Other polymers include, but are not
limited to, polyanhydrides, poly(ester anhydrides), polyhydroxy
acids, such as polylactide (PLA), polyglycolide (PGA),
poly(lactide-co-glycolide) (PLGA), poly-3-hydroxybutyrate (PHB) and
copolymers thereof, poly-4-hydroxybutyrate (P4HB) and copolymers
thereof, polycaprolactone and copolymers thereof, and combinations
thereof. Alternatively, the drug(s) can be incorporated into
microparticles prepared from materials which are insoluble in
aqueous solution or slowly soluble in aqueous solution, but are
capable of degrading within the GI tract by means including
enzymatic degradation, surfactant action of bile acids, and/or
mechanical erosion. As used herein, the term "slowly soluble in
water" refers to materials that are not dissolved in water within a
period of 30 minutes. Preferred examples include fats, fatty
substances, waxes, wax-like substances and mixtures thereof.
Suitable fats and fatty substances include fatty alcohols (such as
lauryl, myristyl stearyl, cetyl or cetostearyl alcohol), fatty
acids and derivatives, including but not limited to fatty acid
esters, fatty acid glycerides (mono-, di- and tri-glycerides), and
hydrogenated fats. Specific examples include, but are not limited
to hydrogenated vegetable oil, hydrogenated cottonseed oil,
hydrogenated castor oil, hydrogenated oils available under the
trade name Sterotex.RTM., stearic acid, cocoa butter, and stearyl
alcohol. Suitable waxes and wax-like materials include natural or
synthetic waxes, hydrocarbons, and normal waxes. Specific examples
of waxes include beeswax, glycowax, castor wax, carnauba wax,
paraffins and candelilla wax. As used herein, a wax-like material
is defined as any material which is normally solid at room
temperature and has a melting point of from about 30 to 300.degree.
C.
[0075] In some cases, it may be desirable to alter the rate of
water penetration into the microparticles. To this end,
rate-controlling (wicking) agents may be formulated along with the
fats or waxes listed above. Examples of rate-controlling materials
include certain starch derivatives (e.g., waxy maltodextrin and
drum dried corn starch), cellulose derivatives (e.g.,
hydroxypropylmethyl-cellulose, hydroxypropylcellulose,
methylcellulose, and carboxymethyl-cellulose), alginic acid,
lactose and talc. Additionally, a pharmaceutically acceptable
surfactant (for example, lecithin) may be added to facilitate the
degradation of such microparticles.
[0076] Proteins which are water insoluble, such as zein, can also
be used as materials for the formation of drug containing
microparticles. Additionally, proteins, polysaccharides and
combinations thereof which are water soluble can be formulated with
drug into microparticles and subsequently cross-linked to form an
insoluble network. For example, cyclodextrins can be complexed with
individual drug molecules and subsequently cross-linked.
[0077] Encapsulation or incorporation of drug into carrier
materials to produce drug containing microparticles can be achieved
through known pharmaceutical formulation techniques. In the case of
formulation in fats, waxes or wax-like materials, the carrier
material is typically heated above its melting temperature and the
drug is added to form a mixture comprising drug particles suspended
in the carrier material, drug dissolved in the carrier material, or
a mixture thereof. Microparticles can be subsequently formulated
through several methods including, but not limited to, the
processes of congealing, extrusion, spray chilling or aqueous
dispersion. In a preferred process, wax is heated above its melting
temperature, drug is added, and the molten wax-drug mixture is
congealed under constant stirring as the mixture cools.
Alternatively, the molten wax-drug mixture can be extruded and
spheronized to form pellets or beads. These processes are known in
the art.
[0078] For some carrier materials it may be desirable to use a
solvent evaporation technique to produce drug containing
microparticles. In this case drug and carrier material are
co-dissolved in a mutual solvent and microparticles can
subsequently be produced by several techniques including, but not
limited to, forming an emulsion in water or other appropriate
media, spray drying or by evaporating off the solvent from the bulk
solution and milling the resulting material.
[0079] In some embodiments, drug in a particulate form is
homogeneously dispersed in a water-insoluble or slowly water
soluble material. To minimize the size of the drug particles within
the composition, the drug powder itself may be milled to generate
fine particles prior to formulation. The process of jet milling,
known in the pharmaceutical art, can be used for this purpose. In
some embodiments drug in a particulate form is homogeneously
dispersed in a wax or wax like substance by heating the wax or wax
like substance above its melting point and adding the drug
particles while stirring the mixture. In this case a
pharmaceutically acceptable surfactant may be added to the mixture
to facilitate the dispersion of the drug particles.
[0080] The particles can also be coated with one or more modified
release coatings. Solid esters of fatty acids, which are hydrolyzed
by lipases, can be spray coated onto microparticles or drug
particles. Zein is an example of a naturally water-insoluble
protein. It can be coated onto drug containing microparticles or
drug particles by spray coating or by wet granulation techniques.
In addition to naturally water-insoluble materials, some substrates
of digestive enzymes can be treated with cross-linking procedures,
resulting in the formation of non-soluble networks. Many methods of
cross-linking proteins, initiated by both chemical and physical
means, have been reported. One of the most common methods to obtain
cross-linking is the use of chemical cross-linking agents. Examples
of chemical cross-linking agents include aldehydes (gluteraldehyde
and formaldehyde), epoxy compounds, carbodiimides, and genipin. In
addition to these cross-linking agents, oxidized and native sugars
have been used to cross-link gelatin. Cross-linking can also be
accomplished using enzymatic means; for example, transglutaminase
has been approved as a GRAS substance for cross-linking seafood
products. Finally, cross-linking can be initiated by physical means
such as thermal treatment, UV irradiation and gamma
irradiation.
[0081] To produce a coating layer of cross-linked protein
surrounding drug containing microparticles or drug particles, a
water soluble protein can be spray coated onto the microparticles
and subsequently cross-linked by the one of the methods described
above. Alternatively, drug containing microparticles can be
microencapsulated within protein by coacervation-phase separation
(for example, by the addition of salts) and subsequently
cross-linked. Some suitable proteins for this purpose include
gelatin, albumin, casein, and gluten.
[0082] Polysaccharides can also be cross-linked to form a
water-insoluble network. For many polysaccharides, this can be
accomplished by reaction with calcium salts or multivalent cations
which cross-link the main polymer chains. Pectin, alginate,
dextran, amylose and guar gum are subject to cross-linking in the
presence of multivalent cations. Complexes between oppositely
charged polysaccharides can also be formed; pectin and chitosan,
for example, can be complexed via electrostatic interactions.
[0083] In certain embodiments, it may be desirable to provide
continuous delivery of the gamma-hydroxybutyrate to a patient in
need thereof. For intravenous or intraarterial routes, this can be
accomplished using drip systems, such as by intravenous
administration. For topical applications, repeated application can
be done or a patch can be used to provide continuous administration
of the gamma-hydroxybutyrate over an extended period of time.
[0084] 2. Injectable/Implantable Solid Implants
[0085] The gamma-hydroxybutyrate described herein can be
incorporated into injectable/implantable solid or semi-solid
implants, such as polymeric implants. In one embodiment, the
gamma-hydroxybutyrate are incorporated into a polymer that is a
liquid or paste at room temperature, but upon contact with aqueous
medium, such as physiological fluids, exhibits an increase in
viscosity to form a semi-solid or solid material. Exemplary
polymers include, but are not limited to, hydroxyalkanoic acid
polyesters derived from the copolymerization of at least one
unsaturated hydroxy fatty acid copolymerized with hydroxyalkanoic
acids. The polymer can be melted, mixed with the active substance
and cast or injection molded into a device. Such melt fabrication
require polymers having a melting point that is below the
temperature at which the substance to be delivered and polymer
degrade or become reactive. The device can also be prepared by
solvent casting where the polymer is dissolved in a solvent and the
drug dissolved or dispersed in the polymer solution and the solvent
is then evaporated. Solvent processes require that the polymer be
soluble in organic solvents. Another method is compression molding
of a mixed powder of the polymer and the drug or polymer particles
loaded with the active agent.
[0086] Alternatively, the gamma-hydroxybutyrate can be incorporated
into a polymer matrix and molded, compressed, or extruded into a
device that is a solid at room temperature. For example, the
gamma-hydroxybutyrate can be incorporated into a biodegradable
polymer, such as polyanhydrides, polyhydroalkanoic acids (PHAs),
PLA, PGA, PLGA, polycaprolactone, polyesters, polyamides,
polyorthoesters, polyphosphazenes, proteins and polysaccharides
such as collagen, hyaluronic acid, albumin and gelatin, and
combinations thereof and compressed into solid device, such as
disks, or extruded into a device, such as rods.
[0087] The release of the one or more gamma-hydroxybutyrate from
the implant can be varied by selection of the polymer, the
molecular weight of the polymer, and/or modification of the polymer
to increase degradation, such as the formation of pores and/or
incorporation of hydrolyzable linkages. Methods for modifying the
properties of biodegradable polymers to vary the release profile of
the gamma-hydroxybutyrate from the implant are well known in the
art.
[0088] B. Enteral Formulations
[0089] Suitable oral dosage forms include tablets, capsules,
solutions, suspensions, syrups, and lozenges. Tablets can be made
using compression or molding techniques well known in the art.
Gelatin or non-gelatin capsules can prepared as hard or soft
capsule shells, which can encapsulate liquid, solid, and semi-solid
fill materials, using techniques well known in the art.
Formulations may be prepared using a pharmaceutically acceptable
carrier. As generally used herein "carrier" includes, but is not
limited to, diluents, preservatives, binders, lubricants,
disintegrators, swelling agents, fillers, stabilizers, and
combinations thereof.
[0090] Carrier also includes all components of the coating
composition which may include plasticizers, pigments, colorants,
stabilizing agents, and glidants. Delayed release dosage
formulations may be prepared as described in standard references.
These references provide information on carriers, materials,
equipment and process for preparing tablets and capsules and
delayed release dosage forms of tablets, capsules, and
granules.
[0091] Examples of suitable coating materials include, but are not
limited to, cellulose polymers such as cellulose acetate phthalate,
hydroxypropyl cellulose, hydroxypropyl methylcellulose,
hydroxypropyl methylcellulose phthalate and hydroxypropyl
methylcellulose acetate succinate; polyvinyl acetate phthalate,
acrylic acid polymers and copolymers, and methacrylic resins that
are commercially available under the trade name EUDRAGIT.RTM. (Roth
Pharma, Westerstadt, Germany), zein, shellac, and
polysaccharides.
[0092] Additionally, the coating material may contain conventional
carriers such as plasticizers, pigments, colorants, glidants,
stabilization agents, pore formers and surfactants.
[0093] Optional pharmaceutically acceptable excipients include, but
are not limited to, diluents, binders, lubricants, disintegrants,
colorants, stabilizers, and surfactants. Diluents, also referred to
as "fillers," are typically necessary to increase the bulk of a
solid dosage form so that a practical size is provided for
compression of tablets or formation of beads and granules. Suitable
diluents include, but are not limited to, dicalcium phosphate
dihydrate, calcium sulfate, lactose, sucrose, mannitol, sorbitol,
cellulose, microcrystalline cellulose, kaolin, sodium chloride, dry
starch, hydrolyzed starches, pregelatinized starch, silicone
dioxide, titanium oxide, magnesium aluminum silicate and powdered
sugar.
[0094] Binders are used to impart cohesive qualities to a solid
dosage formulation, and thus ensure that a tablet or bead or
granule remains intact after the formation of the dosage forms.
Suitable binder materials include, but are not limited to, starch,
pregelatinized starch, gelatin, sugars (including sucrose, glucose,
dextrose, lactose and sorbitol), polyethylene glycol, waxes,
natural and synthetic gums such as acacia, tragacanth, sodium
alginate, cellulose, including hydroxypropylmethylcellulose,
hydroxypropylcellulose, ethylcellulose, and veegum, and synthetic
polymers such as acrylic acid and methacrylic acid copolymers,
methacrylic acid copolymers, methyl methacrylate copolymers,
aminoalkyl methacrylate copolymers, polyacrylic
acid/polymethacrylic acid and polyvinylpyrrolidone.
[0095] Lubricants are used to facilitate tablet manufacture.
Examples of suitable lubricants include, but are not limited to,
magnesium stearate, calcium stearate, stearic acid, glycerol
behenate, polyethylene glycol, talc, and mineral oil.
[0096] Disintegrants are used to facilitate dosage form
disintegration or "breakup" after administration, and generally
include, but are not limited to, starch, sodium starch glycolate,
sodium carboxymethyl starch, sodium carboxymethylcellulose,
hydroxypropyl cellulose, pregelatinized starch, clays, cellulose,
alginine, gums or cross linked polymers, such as cross-linked PVP
(Polyplasdone.RTM. XL from OAF Chemical Corp).
[0097] Stabilizers are used to inhibit or retard drug decomposition
reactions which include, by way of example, oxidative reactions.
Suitable stabilizers include, but are not limited to, antioxidants,
butylated hydroxytoluene (BHT); ascorbic acid, its salts and
esters; Vitamin E, tocopherol and its salts; sulfites such as
sodium metabisulphite; cysteine and its derivatives; citric acid;
propyl gallate, and butylated hydroxyanisole (BHA).
[0098] In some embodiments, the formulation is in the form of a
solid dosage form, such as a capsule or tablet, wherein the
formulation is an immediate release dosage form releasing at least
85, 86, 87, 88, 89, 90, 91, 92, 93, 94, or 95% of the gamma
hydroxybutyrate in less than an hour as measured in de-ionized
water using USP Apparatus 2 at 37.degree. C..+-.2.degree. C. with
paddles at 50 rpm.
[0099] 1. Controlled Release Formulations
[0100] Oral dosage forms, such as capsules, tablets, solutions, and
suspensions, can for formulated for controlled release. For
example, the gamma-hydroxybutyrate and optional one or more
additional active agents can be formulated into nanoparticles,
microparticles, and combinations thereof, and encapsulated in a
soft or hard gelatin or non-gelatin capsule or dispersed in a
dispersing medium to form an oral suspension or syrup. The
particles can be formed of the drug and a controlled release
polymer or matrix. Alternatively, the drug particles can be coated
with one or more controlled release coatings prior to incorporation
in to the finished dosage form.
[0101] In another embodiment, the gamma-hydroxybutyrate and
optional one or more additional active agents are dispersed in a
matrix material, which gels or emulsifies upon contact with an
aqueous medium, such as physiological fluids. In the case of gels,
the matrix swells entrapping the active agents, which are released
slowly over time by diffusion and/or degradation of the matrix
material. Such matrices can be formulated as tablets or as fill
materials for hard and soft capsules.
[0102] In still another embodiment, the gamma-hydroxybutyrate, and
optional one or more additional active agents are formulated into a
sold oral dosage form, such as a tablet or capsule, and the solid
dosage form is coated with one or more controlled release coatings,
such as a delayed release coatings or extended release coatings.
The coating or coatings may also contain the gamma-hydroxybutyrate
and/or additional active agents.
[0103] i. Extended Release Dosage Forms
[0104] The extended release formulations are generally prepared as
diffusion or osmotic systems, which are known in the art. A
diffusion system typically consists of two types of devices, a
reservoir and a matrix, and is well known and described in the art.
The matrix devices are generally prepared by compressing the drug
with a slowly dissolving polymer carrier into a tablet form. The
three major types of materials used in the preparation of matrix
devices are insoluble plastics, hydrophilic polymers, and fatty
compounds. Plastic matrices include, but are not limited to, methyl
acrylate-methyl methacrylate, polyvinyl chloride, and polyethylene.
Hydrophilic polymers include, but are not limited to, cellulosic
polymers such as methyl and ethyl cellulose, hydroxyalkylcelluloses
such as hydroxypropyl-cellulose, hydroxypropylmethylcellulose,
sodium carboxymethylcellulose, and Carbopol.RTM. 934, polyethylene
oxides and mixtures thereof. Fatty compounds include, but are not
limited to, various waxes such as carnauba wax and glyceryl
tristearate and wax-type substances including hydrogenated castor
oil or hydrogenated vegetable oil, or mixtures thereof.
[0105] In certain preferred embodiments, the plastic material is a
pharmaceutically acceptable acrylic polymer, including but not
limited to, acrylic acid and methacrylic acid copolymers, methyl
methacrylate, methyl methacrylate copolymers, ethoxyethyl
methacrylates, cyanoethyl methacrylate, aminoalkyl methacrylate
copolymer, poly(acrylic acid), poly(methacrylic acid), methacrylic
acid alkylamine copolymer poly(methyl methacrylate),
poly(methacrylic acid)(anhydride), polymethacrylate,
polyacrylamide, poly(methacrylic acid anhydride), and glycidyl
methacrylate copolymers.
[0106] In certain preferred embodiments, the acrylic polymer is
comprised of one or more ammonio methacrylate copolymers. Ammonio
methacrylate copolymers are well known in the art, and are
described in NF XVII as fully polymerized copolymers of acrylic and
methacrylic acid esters with a low content of quaternary ammonium
groups.
[0107] In one preferred embodiment, the acrylic polymer is an
acrylic resin lacquer such as that which is commercially available
from Rohm Pharma under the tradename Eudragit.RTM.. In further
preferred embodiments, the acrylic polymer comprises a mixture of
two acrylic resin lacquers commercially available from Rohm Pharma
under the tradenames Eudragit.RTM. RL30D and Eudragit.RTM. RS30D,
respectively. Eudragit.RTM. RL30D and Eudragit.RTM. RS30D are
copolymers of acrylic and methacrylic esters with a low content of
quaternary ammonium groups, the molar ratio of ammonium groups to
the remaining neutral (meth)acrylic esters being 1:20 in
Eudragit.RTM. RL30D and 1:40 in Eudragit.RTM. RS30D. The mean
molecular weight is about 150,000. Edragit.RTM. S-100 and
Eudragit.RTM. L-100 are also preferred. The code designations RL
(high permeability) and RS (low permeability) refer to the
permeability properties of these agents. Eudragit.RTM. RL/RS
mixtures are insoluble in water and in digestive fluids. However,
multiparticulate systems formed to include the same are swellable
and permeable in aqueous solutions and digestive fluids.
[0108] The polymers described above such as Eudragit.RTM. RL/RS may
be mixed together in any desired ratio in order to ultimately
obtain a sustained-release formulation having a desirable
dissolution profile. Desirable sustained-release multiparticulate
systems may be obtained, for instance, from 100% Eudragit.RTM. RL,
50% Eudragit.RTM. RL and 50% Eudragit.RTM. RS, and 10%
Eudragit.RTM. RL and 90% Eudragit.RTM. RS. One skilled in the art
will recognize that other acrylic polymers may also be used, such
as, for example, Eudragit.RTM. L.
[0109] Alternatively, extended release formulations can be prepared
using osmotic systems or by applying a semi-permeable coating to
the dosage form. In the latter case, the desired drug release
profile can be achieved by combining low permeable and high
permeable coating materials in suitable proportion.
[0110] The devices with different drug release mechanisms described
above can be combined in a final dosage form comprising single or
multiple units. Examples of multiple units include, but are not
limited to, multilayer tablets and capsules containing tablets,
beads, or granules. An immediate release portion can be added to
the extended release system by means of either applying an
immediate release layer on top of the extended release core using a
coating or compression process or in a multiple unit system such as
a capsule containing extended and immediate release beads.
[0111] Extended release tablets containing hydrophilic polymers are
prepared by techniques commonly known in the art such as direct
compression, wet granulation, or dry granulation. Their
formulations usually incorporate polymers, diluents, binders, and
lubricants as well as the active pharmaceutical ingredient. The
usual diluents include inert powdered substances such as starches,
powdered cellulose, especially crystalline and microcrystalline
cellulose, sugars such as fructose, mannitol and sucrose, grain
flours and similar edible powders. Typical diluents include, for
example, various types of starch, lactose, mannitol, kaolin,
calcium phosphate or sulfate, inorganic salts such as sodium
chloride and powdered sugar. Powdered cellulose derivatives are
also useful. Typical tablet binders include substances such as
starch, gelatin and sugars such as lactose, fructose, and glucose.
Natural and synthetic gums, including acacia, alginates,
methylcellulose, and polyvinylpyrrolidone can also be used.
Polyethylene glycol, hydrophilic polymers, ethylcellulose and waxes
can also serve as binders. A lubricant is necessary in a tablet
formulation to prevent the tablet and punches from sticking in the
die. The lubricant is chosen from such slippery solids as talc,
magnesium and calcium stearate, stearic acid and hydrogenated
vegetable oils.
[0112] Extended release tablets containing wax materials are
generally prepared using methods known in the art such as a direct
blend method, a congealing method, and an aqueous dispersion
method. In the congealing method, the drug is mixed with a wax
material and either spray-congealed or congealed and screened and
processed.
[0113] In some embodiments, the formulation is a controlled release
formulation in the form of a solid dosage form, such as a capsule
or tablet. The formulation can contain a core containing gamma
hydroxybutyrate or a salt thereof and one or more materials, such
as polymeric materials, which provide controlled release of the
gamma hydroxybutyrate. The core can release the release the gamma
hydroxybutyrate over an extended period of time, e.g., greater than
2, 3, 4, 6, 7, or 8 hours, preferably 6-8 hours. The formulation
can also contain an immediate release coating containing gamma
hydroxybutyrate which releases a substantial portion (greater than
85, 86, 87, 88, 89, 90, 91, 92, 93, 94, or 95%) of the gamma
hydroxybutyrate in less than an hour as measured in de-ionized
water using USP Apparatus 2 at 37.degree. C..+-.2.degree. C. with
paddles at 50 rpm.
[0114] ii. Delayed Release Dosage Forms
[0115] Delayed release formulations can be created by coating a
solid dosage form with a polymer film, which is insoluble in the
acidic environment of the stomach, and soluble in the neutral
environment of the small intestine.
[0116] The delayed release dosage units can be prepared, for
example, by coating a drug or a drug-containing composition with a
selected coating material. The drug-containing composition may be,
e.g., a tablet for incorporation into a capsule, a tablet for use
as an inner core in a "coated core" dosage form, or a plurality of
drug-containing beads, particles or granules, for incorporation
into either a tablet or capsule. Preferred coating materials
include bioerodible, gradually hydrolyzable, gradually
water-soluble, and/or enzymatically degradable polymers, and may be
conventional "enteric" polymers. Enteric polymers, as will be
appreciated by those skilled in the art, become soluble in the
higher pH environment of the lower gastrointestinal tract or slowly
erode as the dosage form passes through the gastrointestinal tract,
while enzymatically degradable polymers are degraded by bacterial
enzymes present in the lower gastrointestinal tract, particularly
in the colon. Suitable coating materials for effecting delayed
release include, but are not limited to, cellulosic polymers such
as hydroxypropyl cellulose, hydroxyethyl cellulose, hydroxymethyl
cellulose, hydroxypropyl methyl cellulose, hydroxypropyl methyl
cellulose acetate succinate, hydroxypropylmethyl cellulose
phthalate, methylcellulose, ethyl cellulose, cellulose acetate,
cellulose acetate phthalate, cellulose acetate trimellitate and
carboxymethylcellulose sodium; acrylic acid polymers and
copolymers, preferably formed from acrylic acid, methacrylic acid,
methyl acrylate, ethyl acrylate, methyl methacrylate and/or ethyl
methacrylate, and other methacrylic resins that are commercially
available under the tradename Eudragit.RTM. (Rohm Pharma;
Westerstadt, Germany), including Eudragit.RTM. L30D-55 and L100-55
(soluble at pH 5.5 and above), Eudragit.RTM. L-100 (soluble at pH
6.0 and above), Eudragit.RTM. S (soluble at pH 7.0 and above, as a
result of a higher degree of esterification), and Eudragits.RTM.
NE, RL and RS (water-insoluble polymers having different degrees of
permeability and expandability); vinyl polymers and copolymers such
as polyvinyl pyrrolidone, vinyl acetate, vinylacetate phthalate,
vinylacetate crotonic acid copolymer, and ethylene-vinyl acetate
copolymer; enzymatically degradable polymers such as azo polymers,
pectin, chitosan, amylose and guar gum; zein and shellac.
Combinations of different coating materials may also be used.
Multi-layer coatings using different polymers may also be
applied.
[0117] The preferred coating weights for particular coating
materials may be readily determined by those skilled in the art by
evaluating individual release profiles for tablets, beads and
granules prepared with different quantities of various coating
materials. It is the combination of materials, method and form of
application that produce the desired release characteristics, which
one can determine only from the clinical studies.
[0118] The P4HB polymer, deuterated P4HB polymer, 4HB oligomers or
deuterated 4HB oligomers may be used as the coating material with
the added benefit that they are also a source of the 4-HB. For
example, a coating containing one or more of the above can be
applied to a solid dosage form such as a tablet or capsule to
provide immediate release and/or controlled release of 4HB.
[0119] The coating composition may include conventional additives,
such as plasticizers, pigments, colorants, stabilizing agents,
glidants, etc. A plasticizer is normally present to reduce the
fragility of the coating, and will generally represent about 10 wt.
% to 50 wt. % relative to the dry weight of the polymer. Examples
of typical plasticizers include polyethylene glycol, propylene
glycol, triacetin, dimethyl phthalate, diethyl phthalate, dibutyl
phthalate, dibutyl sebacate, triethyl citrate, tributyl citrate,
triethyl acetyl citrate, castor oil and acetylated monoglycerides.
A stabilizing agent is preferably used to stabilize particles in
the dispersion. Typical stabilizing agents are nonionic emulsifiers
such as sorbitan esters, polysorbates and polyvinylpyrrolidone.
Glidants are recommended to reduce sticking effects during film
formation and drying, and will generally represent approximately 25
wt. % to 100 wt. % of the polymer weight in the coating solution.
One effective glidant is talc. Other glidants such as magnesium
stearate and glycerol monostearates may also be used. Pigments such
as titanium dioxide may also be used. Small quantities of an
anti-foaming agent, such as a silicone (e.g., simethicone), may
also be added to the coating composition.
[0120] C. Topical Formulations
[0121] Suitable dosage forms for topical administration include
creams, ointments, salves, sprays, gels, lotions, emulsions, and
transdermal patches. The formulation may be formulated for
transmucosal, transepithelial, transendothelial, or transdermal
administration. The compounds can also be formulated for intranasal
delivery, pulmonary delivery, or inhalation. The compositions may
further contain one or more chemical penetration enhancers,
membrane permeability agents, membrane transport agents,
emollients, surfactants, stabilizers, and combination thereof
"Emollients" are an externally applied agent that softens or
soothes skin and are generally known in the art and listed in
compendia, such as the "Handbook of Pharmaceutical Excipients",
4.sup.th Ed., Pharmaceutical Press, 2003. These include, without
limitation, almond oil, castor oil, ceratonia extract, cetostearoyl
alcohol, cetyl alcohol, cetyl esters wax, cholesterol, cottonseed
oil, cyclomethicone, ethylene glycol palmitostearate, glycerin,
glycerin monostearate, glyceryl monooleate, isopropyl myristate,
isopropyl palmitate, lanolin, lecithin, light mineral oil,
medium-chain triglycerides, mineral oil and lanolin alcohols,
petrolatum, petrolatum and lanolin alcohols, soybean oil, starch,
stearyl alcohol, sunflower oil, xylitol and combinations thereof.
In one embodiment, the emollients are ethylhexylstearate and
ethylhexyl palmitate.
[0122] "Surfactants" are surface-active agents that lower surface
tension and thereby increase the emulsifying, foaming, dispersing,
spreading and wetting properties of a product. Suitable non-ionic
surfactants include emulsifying wax, glyceryl monooleate,
polyoxyethylene alkyl ethers, polyoxyethylene castor oil
derivatives, polysorbate, sorbitan esters, benzyl alcohol, benzyl
benzoate, cyclodextrins, glycerin monostearate, poloxamer, povidone
and combinations thereof. In one embodiment, the non-ionic
surfactant is stearyl alcohol.
[0123] "Emulsifiers" are surface active substances which promote
the suspension of one liquid in another and promote the formation
of a stable mixture, or emulsion, of oil and water. Common
emulsifiers are: metallic soaps, certain animal and vegetable oils,
and various polar compounds. Suitable emulsifiers include acacia,
anionic emulsifying wax, calcium stearate, carbomers, cetostearyl
alcohol, cetyl alcohol, cholesterol, diethanolamine, ethylene
glycol palmitostearate, glycerin monostearate, glyceryl monooleate,
hydroxypropyl cellulose, hypromellose, lanolin, hydrous, lanolin
alcohols, lecithin, medium-chain triglycerides, methylcellulose,
mineral oil and lanolin alcohols, monobasic sodium phosphate,
monoethanolamine, nonionic emulsifying wax, oleic acid, poloxamer,
poloxamers, polyoxyethylene alkyl ethers, polyoxyethylene castor
oil derivatives, polyoxyethylene sorbitan fatty acid esters,
polyoxyethylene stearates, propylene glycol alginate,
self-emulsifying glyceryl monostearate, sodium citrate dehydrate,
sodium lauryl sulfate, sorbitan esters, stearic acid, sunflower
oil, tragacanth, triethanolamine, xanthan gum and combinations
thereof. In one embodiment, the emulsifier is glycerol
stearate.
[0124] Suitable classes of penetration enhancers are known in the
art and include, but are not limited to, fatty alcohols, fatty acid
esters, fatty acids, fatty alcohol ethers, amino acids,
phospholipids, lecithins, cholate salts, enzymes, amines and
amides, complexing agents (liposomes, cyclodextrins, modified
celluloses, and diimides), macrocyclics, such as macrocylic
lactones, ketones, and anhydrides and cyclic ureas, surfactants,
N-methyl pyrrolidones and derivatives thereof, DMSO and related
compounds, ionic compounds, azone and related compounds, and
solvents, such as alcohols, ketones, amides, polyols (e.g.,
glycols). Examples of these classes are known in the art.
[0125] i. Lotions, Creams, Gels, Ointments, Emulsions, and
Foams
[0126] "Hydrophilic" as used herein refers to substances that have
strongly polar groups that readily interact with water.
[0127] "Lipophilic" refers to compounds having an affinity for
lipids.
[0128] "Amphiphilic" refers to a molecule combining hydrophilic and
lipophilic (hydrophobic) properties
[0129] "Hydrophobic" as used herein refers to substances that lack
an affinity for water; tending to repel and not absorb water as
well as not dissolve in or mix with water.
[0130] A "gel" is a colloid in which the dispersed phase has
combined with the continuous phase to produce a semisolid material,
such as jelly.
[0131] An "oil" is a composition containing at least 95% wt of a
lipophilic substance. Examples of lipophilic substances include but
are not limited to naturally occurring and synthetic oils, fats,
fatty acids, lecithins, triglycerides and combinations thereof.
[0132] A "continuous phase" refers to the liquid in which solids
are suspended or droplets of another liquid are dispersed, and is
sometimes called the external phase. This also refers to the fluid
phase of a colloid within which solid or fluid particles are
distributed. If the continuous phase is water (or another
hydrophilic solvent), water-soluble or hydrophilic drugs will
dissolve in the continuous phase (as opposed to being dispersed).
In a multiphase formulation (e.g., an emulsion), the discreet phase
is suspended or dispersed in the continuous phase.
[0133] An "emulsion" is a composition containing a mixture of
non-miscible components homogenously blended together. In
particular embodiments, the non-miscible components include a
lipophilic component and an aqueous component. An emulsion is a
preparation of one liquid distributed in small globules throughout
the body of a second liquid. The dispersed liquid is the
discontinuous phase, and the dispersion medium is the continuous
phase. When oil is the dispersed liquid and an aqueous solution is
the continuous phase, it is known as an oil-in-water emulsion,
whereas when water or aqueous solution is the dispersed phase and
oil or oleaginous substance is the continuous phase, it is known as
a water-in-oil emulsion. Either or both of the oil phase and the
aqueous phase may contain one or more surfactants, emulsifiers,
emulsion stabilizers, buffers, and other excipients. Preferred
excipients include surfactants, especially non-ionic surfactants;
emulsifying agents, especially emulsifying waxes; and liquid
non-volatile non-aqueous materials, particularly glycols such as
propylene glycol. The oil phase may contain other oily
pharmaceutically approved excipients. For example, materials such
as hydroxylated castor oil or sesame oil may be used in the oil
phase as surfactants or emulsifiers.
[0134] An emulsion is a preparation of one liquid distributed in
small globules throughout the body of a second liquid. The
dispersed liquid is the discontinuous phase, and the dispersion
medium is the continuous phase. When oil is the dispersed liquid
and an aqueous solution is the continuous phase, it is known as an
oil-in-water emulsion, whereas when water or aqueous solution is
the dispersed phase and oil or oleaginous substance is the
continuous phase, it is known as a water-in-oil emulsion. The oil
phase may consist at least in part of a propellant, such as an HFA
propellant. Either or both of the oil phase and the aqueous phase
may contain one or more surfactants, emulsifiers, emulsion
stabilizers, buffers, and other excipients. Preferred excipients
include surfactants, especially non-ionic surfactants; emulsifying
agents, especially emulsifying waxes; and liquid non-volatile
non-aqueous materials, particularly glycols such as propylene
glycol. The oil phase may contain other oily pharmaceutically
approved excipients. For example, materials such as hydroxylated
castor oil or sesame oil may be used in the oil phase as
surfactants or emulsifiers.
[0135] A sub-set of emulsions are the self-emulsifying systems.
These drug delivery systems are typically capsules (hard shell or
soft shell) comprised of the drug dispersed or dissolved in a
mixture of surfactant(s) and lipophilic liquids such as oils or
other water immiscible liquids. When the capsule is exposed to an
aqueous environment and the outer gelatin shell dissolves, contact
between the aqueous medium and the capsule contents instantly
generates very small emulsion droplets. These typically are in the
size range of micelles or nanoparticles. No mixing force is
required to generate the emulsion as is typically the case in
emulsion formulation processes.
[0136] A "lotion" is a low- to medium-viscosity liquid formulation.
A lotion can contain finely powdered substances that are in soluble
in the dispersion medium through the use of suspending agents and
dispersing agents. Alternatively, lotions can have as the dispersed
phase liquid substances that are immiscible wit the vehicle and are
usually dispersed by means of emulsifying agents or other suitable
stabilizers. In one embodiment, the lotion is in the form of an
emulsion having a viscosity of between 100 and 1000 centistokes.
The fluidity of lotions permits rapid and uniform application over
a wide surface area. Lotions are typically intended to dry on the
skin leaving a thin coat of their medicinal components on the
skin's surface.
[0137] A "cream" is a viscous liquid or semi-solid emulsion of
either the "oil-in-water" or "water-in-oil type". Creams may
contain emulsifying agents and/or other stabilizing agents. In one
embodiment, the formulation is in the form of a cream having a
viscosity of greater than 1000 centistokes, typically in the range
of 20,000-50,000 centistokes. Creams are often time preferred over
ointments as they are generally easier to spread and easier to
remove.
[0138] The difference between a cream and a lotion is the
viscosity, which is dependent on the amount/use of various oils and
the percentage of water used to prepare the formulations. Creams
are typically thicker than lotions, may have various uses and often
one uses more varied oils/butters, depending upon the desired
effect upon the skin. In a cream formulation, the water-base
percentage is about 60-75% and the oil-base is about 20-30% of the
total, with the other percentages being the emulsifier agent,
preservatives and additives for a total of 100%.
[0139] An "ointment" is a semisolid preparation containing an
ointment base and optionally one or more active agents. Examples of
suitable ointment bases include hydrocarbon bases (e.g.,
petrolatum, white petrolatum, yellow ointment, and mineral oil);
absorption bases (hydrophilic petrolatum, anhydrous lanolin,
lanolin, and cold cream); water-removable bases (e.g., hydrophilic
ointment), and water-soluble bases (e.g., polyethylene glycol
ointments). Pastes typically differ from ointments in that they
contain a larger percentage of solids. Pastes are typically more
absorptive and less greasy that ointments prepared with the same
components.
[0140] A "gel" is a semisolid system containing dispersions of
small or large molecules in a liquid vehicle that is rendered
semisolid by the action of a thickening agent or polymeric material
dissolved or suspended in the liquid vehicle. The liquid may
include a lipophilic component, an aqueous component or both. Some
emulsions may be gels or otherwise include a gel component. Some
gels, however, are not emulsions because they do not contain a
homogenized blend of immiscible components. Suitable gelling agents
include, but are not limited to, modified celluloses, such as
hydroxypropyl cellulose and hydroxyethyl cellulose; Carbopol
homopolymers and copolymers; and combinations thereof. Suitable
solvents in the liquid vehicle include, but are not limited to,
diglycol monoethyl ether, alkylene glycols, such as propylene
glycol; dimethyl isosorbide; alcohols, such as isopropyl alcohol
and ethanol. The solvents are typically selected for their ability
to dissolve the drug. Other additives, which improve the skin feel
and/or emolliency of the formulation, may also be incorporated.
Examples of such additives include, but are not limited, isopropyl
myristate, ethyl acetate, C.sub.12-C.sub.15 alkyl benzoates,
mineral oil, squalane, cyclomethicone, capric/caprylic
triglycerides, and combinations thereof.
[0141] Foams consist of an emulsion in combination with a gaseous
propellant. The gaseous propellant consists primarily of
hydrofluoroalkanes (HFAs). Suitable propellants include HFAs such
as 1,1,1,2-tetrafluoroethane (HFA 134a) and
1,1,1,2,3,3,3-heptafluoropropane (HFA 227), but mixtures and
admixtures of these and other HFAs that are currently approved or
may become approved for medical use are suitable. The propellants
preferably are not hydrocarbon propellant gases which can produce
flammable or explosive vapors during spraying. Furthermore, the
compositions preferably contain no volatile alcohols, which can
produce flammable or explosive vapors during use.
[0142] Buffers are used to control pH of a composition. Preferably,
the buffers buffer the composition from a pH of about 4 to a pH of
about 7.5, more preferably from a pH of about 4 to a pH of about 7,
and most preferably from a pH of about 5 to a pH of about 7. In a
preferred embodiment, the buffer is triethanolamine.
[0143] Preservatives can be used to prevent the growth of fungi and
microorganisms. Suitable antifungal and antimicrobial agents
include, but are not limited to, benzoic acid, butylparaben, ethyl
paraben, methyl paraben, propylparaben, sodium benzoate, sodium
propionate, benzalkonium chloride, benzethonium chloride, benzyl
alcohol, cetylpyridinium chloride, chlorobutanol, phenol,
phenylethyl alcohol, and thimerosal.
[0144] In certain embodiments, it may be desirable to provide
continuous delivery of gamma-hydroxybutyrate to a patient in need
thereof. For topical applications, repeated application can be done
or a patch can be used to provide continuous administration of the
gamma-hydroxybutyrate over an extended period of time.
[0145] D. Pulmonary Formulations
[0146] In one embodiment, the gamma-hydroxybutyrate are formulated
for pulmonary delivery, such as intranasal administration or oral
inhalation. The respiratory tract is the structure involved in the
exchange of gases between the atmosphere and the blood stream. The
lungs are branching structures ultimately ending with the alveoli
where the exchange of gases occurs. The alveolar surface area is
the largest in the respiratory system and is where drug absorption
occurs. The alveoli are covered by a thin epithelium without cilia
or a mucus blanket and secrete surfactant phospholipids.
[0147] The respiratory tract encompasses the upper airways,
including the oropharynx and larynx, followed by the lower airways,
which include the trachea followed by bifurcations into the bronchi
and bronchioli. The upper and lower airways are called the
conducting airways. The terminal bronchioli then divide into
respiratory bronchioli which then lead to the ultimate respiratory
zone, the alveoli, or deep lung. The deep lung, or alveoli, are the
primary target of inhaled therapeutic aerosols for systemic drug
delivery.
[0148] Pulmonary administration of therapeutic compositions
comprised of low molecular weight drugs has been observed, for
example, beta-androgenic antagonists to treat asthma. Other
therapeutic agents that are active in the lungs have been
administered systemically and targeted via pulmonary absorption.
Nasal delivery is considered to be a promising technique for
administration of therapeutics for the following reasons: the nose
has a large surface area available for drug absorption due to the
coverage of the epithelial surface by numerous microvilli, the
subepithelial layer is highly vascularized, the venous blood from
the nose passes directly into the systemic circulation and
therefore avoids the loss of drug by first-pass metabolism in the
liver, it offers lower doses, more rapid attainment of therapeutic
blood levels, quicker onset of pharmacological activity, fewer side
effects, high total blood flow per cm3, porous endothelial basement
membrane, and it is easily accessible.
[0149] The term aerosol as used herein refers to any preparation of
a fine mist of particles, which can be in solution or a suspension,
whether or not it is produced using a propellant. Aerosols can be
produced using standard techniques, such as ultrasonication or high
pressure treatment.
[0150] Carriers for pulmonary formulations can be divided into
those for dry powder formulations and for administration as
solutions. Aerosols for the delivery of therapeutic agents to the
respiratory tract are known in the art. For administration via the
upper respiratory tract, the formulation can be formulated into a
solution, e.g., water or isotonic saline, buffered or unbuffered,
or as a suspension, for intranasal administration as drops or as a
spray. Preferably, such solutions or suspensions are isotonic
relative to nasal secretions and of about the same pH, ranging
e.g., from about pH 4.0 to about pH 7.4 or, from pH 6.0 to pH 7.0.
Buffers should be physiologically compatible and include, simply by
way of example, phosphate buffers. For example, a representative
nasal decongestant is described as being buffered to a pH of about
6.2. One skilled in the art can readily determine a suitable saline
content and pH for an innocuous aqueous solution for nasal and/or
upper respiratory administration.
[0151] Preferably, the aqueous solutions is water, physiologically
acceptable aqueous solutions containing salts and/or buffers, such
as phosphate buffered saline (PBS), or any other aqueous solution
acceptable for administration to a animal or human. Such solutions
are well known to a person skilled in the art and include, but are
not limited to, distilled water, de-ionized water, pure or
ultrapure water, saline, phosphate-buffered saline (PBS). Other
suitable aqueous vehicles include, but are not limited to, Ringer's
solution and isotonic sodium chloride. Aqueous suspensions may
include suspending agents such as cellulose derivatives, sodium
alginate, polyvinyl-pyrrolidone and gum tragacanth, and a wetting
agent such as lecithin. Suitable preservatives for aqueous
suspensions include ethyl and n-propyl p-hydroxybenzoate.
[0152] In another embodiment, solvents that are low toxicity
organic (i.e. nonaqueous) class 3 residual solvents, such as
ethanol, acetone, ethyl acetate, tetrahydofuran, ethyl ether, and
propanol may be used for the formulations. The solvent is selected
based on its ability to readily aerosolize the formulation. The
solvent should not detrimentally react with the
gamma-hydroxybutyrate hydroxybutyrate or oligomers of
gamma-hydroxybutyrate. An appropriate solvent should be used that
dissolves the gamma-hydroxybutyrate hydroxybutyrate or oligomers of
gamma-hydroxybutyrate or forms a suspension of the
gamma-hydroxybutyrate. The solvent should be sufficiently volatile
to enable formation of an aerosol of the solution or suspension.
Additional solvents or aerosolizing agents, such as freons, can be
added as desired to increase the volatility of the solution or
suspension.
[0153] In one embodiment, compositions may contain minor amounts of
polymers, surfactants, or other excipients well known to those of
the art. In this context, "minor amounts" means no excipients are
present that might affect or mediate uptake of the
gamma-hydroxybutyrate in the lungs and that the excipients that are
present are present in amount that do not adversely affect uptake
of gamma-hydroxybutyrate in the lungs.
[0154] Dry lipid powders can be directly dispersed in ethanol
because of their hydrophobic character. For lipids stored in
organic solvents such as chloroform, the desired quantity of
solution is placed in a vial, and the chloroform is evaporated
under a stream of nitrogen to form a dry thin film on the surface
of a glass vial. The film swells easily when reconstituted with
ethanol. To fully disperse the lipid molecules in the organic
solvent, the suspension is sonicated. Nonaqueous suspensions of
lipids can also be prepared in absolute ethanol using a reusable
PARI LC Jet+ nebulizer (PARI Respiratory Equipment, Monterey,
Calif.).
[0155] Dry powder formulations ("DPFs") with large particle size
have improved flowability characteristics, such as less
aggregation, easier aerosolization, and potentially less
phagocytosis. Dry powder aerosols for inhalation therapy are
generally produced with mean diameters primarily in the range of
less than 5 microns, although a preferred range is between one and
ten microns in aerodynamic diameter. Large "carrier" particles
(containing no drug) have been co-delivered with therapeutic
aerosols to aid in achieving efficient aerosolization among other
possible benefits.
[0156] Polymeric particles may be prepared using single and double
emulsion solvent evaporation, spray drying, solvent extraction,
solvent evaporation, phase separation, simple and complex
coacervation, interfacial polymerization, and other methods well
known to those of ordinary skill in the art. Particles may be made
using methods for making microspheres or microcapsules known in the
art. The preferred methods of manufacture are by spray drying and
freeze drying, which entails using a solution containing the
surfactant, spraying to form droplets of the desired size, and
removing the solvent.
[0157] The particles may be fabricated with the appropriate
material, surface roughness, diameter and tap density for localized
delivery to selected regions of the respiratory tract such as the
deep lung or upper airways. For example, higher density or larger
particles may be used for upper airway delivery. Similarly, a
mixture of different sized particles, provided with the same or
different EGS may be administered to target different regions of
the lung in one administration.
[0158] Formulations for pulmonary delivery include unilamellar
phospholipid vesicles, liposomes, or lipoprotein particles.
Formulations and methods of making such formulations containing
nucleic acid are well known to one of ordinary skill in the art.
Liposomes are formed from commercially available phospholipids
supplied by a variety of vendors including Avanti Polar Lipids,
Inc. (Birmingham, Ala.). In one embodiment, the liposome can
include a ligand molecule specific for a receptor on the surface of
the target cell to direct the liposome to the target cell.
IV. Methods of Making Gamma-Hydroxybutyrate
[0159] Gamma-hydroxybutyrate or deuterated gamma-hydrobutyrate
having a unique carbon footprint can be prepared by a variety of
techniques. In one embodiment, gamma-butyrolactone or deuterated
gamma-hydrobutyrate is prepared having a particular percentage of
modern carbon. This can be done through a variety of procedures,
including fermentation. By using biobased renewable raw materials
and petroleum-based raw materials in defined ratios, one can
prepare gamma-butyrolactone or deuterated gamma-hydrobutyrate
having a unique carbon footprint and therefore can be traced.
Gamma-butyrolactone or deuterated gamma-butyrolactone can be
converted to gamma-hydroxybutyrate or deuterated
gamma-hydrobutyrate by saponification (e.g., base-catalyzed ring
opening) of the lactone ring. U.S. Patent Application Publication
No. 2011/0028551, the contents of which are incorporated herein,
describes continuous methods for effecting the ring opening of
gamma-butyrolactone to form gamma-hydroxybutyrate. Other procedures
for producing gamma-hydroxybutyrate or deuterated
gamma-hydrobutyrate include the partial hydrogenation of succinic
acid or deuterated forms thereof having a unique carbon footprint
and partial oxidation of butanediol or deuterated forms thereof
have a unique carbon footprint.
[0160] In one embodiment, biobased gamma-butyrolactone is produced
from the conversion to biobased GHB or deuterated
gamma-hydrobutyrate by pyrolysis of poly(4-hydroxybutyrate) or
DP4HB as described in WO 2011/100601 P4HB or DP4HB can be produced
from a variety of biobased, renewable raw materials, such as
glucose or deuterated glucose syrup or D.sub.2O using fermentation
methods. P4HB or DP4Hb can also be prepared from a mixture of
biobased, renewable raw materials and petroleum-based raw materials
using the same fermentation procedures. P4HB or DP4HB can be
pyrolyzed in the presence of Ca(OH).sub.2 to produce GBL or DGBL,
which can be saponified to form GHB or DGHB. P4HB or DP4HB can also
be converted to GHB or DGHB by dissolving purified P4HB or DP4HB in
an organic solvent, such as tetrahydrofuran (THF), and reacted with
a base, such as sodium methoxide, to convert P4HB or DP4Hb directly
to GHB or DGHB. The same procedure can also be used to prepare 4HB
or D4HB oligomers of a desired molecular weight. Biobased GBL or
DGBL or a mixture of biobased GBL or DGBL and petroleum-based GBL
or DGBL can be converted to GHB or DGHB by reacting GBL or DGBL
with a base, such as sodium hydroxide, to form the sodium salt of
gamma-hydroxybutyric acid or deuterated gamma-hydrobutyrate, sodium
gamma-hydroxybutyrate or deuterated sodium gamma-hydrobutyrate.
[0161] GBL or GBH or deuterated forms thereof having a unique
carbon footprint can be prepared from succinic acid or deuterated
forms thereof. Succinic acid having a particular carbon footprint
can be prepared by fermentation of microbial biomass, isolation of
the succinic acid, and catalytic hydrogenation of succinic acid to
form GHB.
[0162] GHB or DGHB having a unique footprint can also be prepared
from 1,4-butanediol or deuterated forms thereof having the unique
carbon footprint. 1,4-butanediol having a particular carbon
footprint can be prepared by fermentation of microbial biomass,
isolation of the 1,4-butanediol, and catalytic oxidation of
1,4-butane diol to form GHB.
[0163] GBL or GHB or deuterated forms thereof can be produced in
very high purity, for example, greater than 95%, 96%, 97%, 98%,
99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.5%, 99.6%, 99.7%, 99.8%,
or 99.9% on a mass basis which requires less purification to
prepare a product for pharmaceutical compositions.
[0164] Methods for making a variety of deuterated compounds via
growth of bacteria in deuterated media is described in WO
1997/007216, which is incorporated herein by reference. Compounds
having a unique carbon footprint can be prepared using the
techniques described therein.
V. Methods of Use of Gamma-Hydroxybutyrate
[0165] Gamma-hydroxybutyrate ("GHB") is a naturally occurring
substance that is widely distributed in the mammalian body, being
present, for example, in the brain, kidney, heart, liver, lung and
muscle. When administered exogenously, GHB readily crosses the
blood-brain barrier and penetrates the brain, producing a number of
neuropharmacological effects. GHB has been used as an intravenous
agent for the induction of anesthesia and for long-term sedation,
without serious side-effects on circulation or respiration, and
without an accompanying seizure-inducing activity in humans. It has
also been suggested that GHB may be a suitable agent for total
intravenous anesthesia in patients with coronary artery disease, as
well as for sedation during spinal anesthesia. Patients with
chronic schizophrenia characterized by autism, inactivity, and
apathy; catatonic schizophrenia; chronic schizophrenia with
hallucination and delusion; atypical psychoses; and chronic brain
syndrome due to trauma, as well as neurotic patients have all been
treated using GHB.
[0166] In addition to these uses, GHB also is used to treat
narcolepsy, a chronic sleep disorder that usually begins in
adolescence or early adulthood and lasts throughout life.
Narcolepsy is characterized by sudden sleep attacks lasting usually
from a few to thirty minutes, paralysis upon lying down or waking,
visual or auditory hallucinations at the onset of sleep, and
temporary loss of muscle tone while awake (cataplexy) or asleep.
Treatment with GHB substantially reduces these signs and symptoms
of narcolepsy in humans. GHB as the sodium salt, known as sodium
oxybate, is sold by Jazz Pharmaceuticals under the name Xyrem to
treat cataplexy and excessive daytime sleepiness in patients with
narcolepsy.
[0167] Other uses of OHB include its application in the
pharmacotherapy of alcoholism, where it has been found to reduce
alcohol craving and consumption, and to ameliorate symptoms of
alcohol withdrawal syndrome in alcoholics. GHB also reportedly aids
patients undergoing withdrawal from opiates and relieves anxiety,
tremor, and muscle rigidity in patients with Parkinson's
disease.
[0168] Administration of GHB also has been reported to protect
neurons and intestinal epithelium against cell death resulting from
experimental ischemia, to drop blood pressure in hypertensive
patients, to increase plasma levels of growth hormone after
injection in healthy subjects, and to stimulate growth hormone and
prolactin production. Administration of GHB also is purported to be
an effective anorectic, heighten sexual desire, produce pleasurable
effects such as euphoria and smooth muscle relaxation, promote
muscle mass, and be able to induce rapid eye movement sleep. PCT WO
99/09972 and U.S. Pat. No. 5,990,162 to Scharf discloses the use of
GHB in the treatment of fibromyalgia and chronic fatigue syndrome.
Administration of GHB also has been shown to increase gastric
emptying, and could be used as a prokinetic drug for treatment of a
number of conditions where improvement in gastrointestinal motility
and gastric emptying is desired. Such conditions include treatment
of malabsorption disorders, and increased uptake of poorly absorbed
drugs. Gamma-butyrolactone which is metabolized to GHB has been
shown to potentiate the effect of gamma-aminobutyric acid on
gastric secretions. GHB has shown anti-ulcer activity against
ulcers induced by indomethacin, restraint stress or pyloric
ligation.
[0169] In animals, GHB produces electroencephalographic (EEG) and
behavioral changes, resembling generalized absence seizures. The
treated animals show arrest of activity which can be aborted by
anti-absence drugs. For this reason, GHB has been used to provide a
reproducible, consistent, pharmacologically specific model for the
study of generalized absence seizures, which is analogous to other
models of absence in the rat. GHB administration also has been used
in animals to normalize cardiovascular function of hemorrhage and
as an anti-ischemic. In mice, GHB was found to exert a
radioprotective effect.
[0170] Infusion of GHB also has been found to possess an
angiogenesis inhibitory effect, making GHB potentially useful in
the treatment of cancer as an anti-angiogenesis agent. GHB also has
been used prophylactically in rats as an antihypoxant, antioxidant,
or actoprotector, increasing survival rates of rats with myocardial
infarction. GHB reportedly prevents heart damage after acute blood
loss.
[0171] GHB may also be administered prophylactically to reduce
inflammation or ischemic or reperfusion injury during surgery.
Prophylactic administration of GHB prevented liver damage to
tetrachloromethane poisoning. The lithium salt of GHB depressed
carrageenan inflammation in a hamster cheek pouch assay.
Prophylactic administration of lithium salt of GHB prevented
inflammation in acute paw edema assay. GHB has been shown to
improve blood flow to ischemic heart tissue. GHB also has been used
to protect frozen liver tissue for transplantation.
[0172] Sodium 4-hydroxybutyrate has been shown to affect
metabolism, as its administration reduced nucleotide catabolism,
glycolysis, lipolysis, and lipid peroxidation. Sodium
hydroxybutyrate also has been shown to stimulate the
pentosophosphate cycle and interfere with metabolic acidosis. Thus
GHB may be used to improve metabolism and to offset the damaging
effects of injury, surgery, ischemia and shock.
[0173] GHB has been shown to prevent the proliferation of cancer
and functions as an antineoplastic agent (Basaki, et al., Gan To
Kagaku Ryoho, 27:93-98 2000)). GHB and gamma-butyrolactone have
been shown to reduce angiogenesis induced by certain types of
cancer cells (Yonekura, et al., Clinical Cancer Research, 5:2185-91
(1999)). GHB also has been shown to be beneficial for the treatment
of lung cancer patients during and after surgery (Leonenkov, et
al., Vopr. Onkol., 39:75-79 (1993)) and this benefit was attributed
to the antihypoxic effects of GHB. Accordingly, GHB can be used to
prevent the spread or proliferation of a cancer.
[0174] The compositions described herein can contain a single
active component, a plurality of active components, and/or one or
more components which can be converted to an active component. For
example, the compositions described herein can contain GHB or DGHB
alone or in combination with GBL, DGBL, P4HB, DP4HB, or
combinations thereof. In other embodiments, the composition
contains GBL or DGBL in combination with P4HB or DP4HB. In still
other embodiments, the composition contains oligomers of GBL or
DGBL in combination with P4HB or DP4HB and monomeric GBL or DGBL.
The compositions can be formulated for controlled release, such as
immediate release, extended release, delayed release, pulsatile
release, and combinations thereof. For example, the composition can
be in the form of a tablet or capsule with a coating containing the
active agent for immediate release and a core (tablet) or fill
(capsule) which provides extended release or delayed release.
EXAMPLES
Example 1
Production of Biobased Gamma-Butyrolactone (GBL) from the Pyrolysis
of a Genetically Engineered Microbe Producing
poly-4-hydroxybutyrate (P4HB)
[0175] In this example biobased GBL is produced for the conversion
to Biobased GHB for use in pharmaceutical applications with
improved monitoring and safety. Biomass containing
poly-4-hydroxybutyrate (poly-4HB) was produced in a 20 L New
Brunswick Scientific fermentor (BioFlo 4500) using a genetically
modified E. coli strain specifically designed for high yield
production of poly-4HB from glucose syrup as the sole carbon feed
source. The use of a renewable resource based feedstock such as
glucose syrup as the sole carbon source enables the production of a
biobased P4HB and hence the production of biobased GBL and
derivatives including biobased gamma-hydroxybutyric acid (GHB).
Examples of the E. coli strains, fermentation conditions, media and
feed conditions are described in U.S. Pat. Nos. 6,316,262;
6,689,589; 7,081,357; and 7,229,804. The E. coli strain generated a
fermentation broth which had a P4HB titer of approximately 100-120
g of P4HB/kg of broth. After fermentation, the broth was washed
with DI water by adding an equal volume of water, mixing for 2
minutes, centrifuging and decanting the water. Next, the washed
broth was mixed with lime (Ca(OH).sub.2 standard hydrated lime 98%,
Mississippi Lime) targeting 4% by wt dry solids. The mixture was
then dried in a rotating drum dryer at 125-130.degree. C. to a
constant weight. Moisture levels in the dried biomass were
approximately 1-2% by weight. The final wt % calcium ion in the
dried broth+P4HB was measured by Ion Chromatography to be 1.9%
(3.5% by wt. Ca(OH).sub.2).
[0176] Pyrolysis of the dried broth+P4HB+Ca(OH).sub.2 was carried
out using a rotating, four inch diameter quartz glass kiln
suspended within a clamshell tube furnace. At the start of the
process, a weighed sample of dried broth+P4HB+Ca(OH).sub.2 was
placed inside of the glass kiln and a nitrogen purge flow
established. The furnace rotation and heat up would then be
started. As the temperature of the furnace reached its set point
value, gases generated by the broth+P4HB+Ca(OH).sub.2 sample would
be swept out of the kiln by the nitrogen purge and enter a series
of glass condensers or chilled traps. The condensers consisted of a
vertical, cooled glass condenser tower with a condensate collection
bulb located at the base. A glycol/water mixture held at 0.degree.
C. was circulated through all of the glass condensers. The cooled
gases that exited the top of the first condenser were directed
downward through a second condenser and through a second condensate
collection bulb before being bubbled through a glass impinger
filled with deionized water.
[0177] For the larger scale pyrolysis experiment, 292 g of dried
broth+P4HB+Ca(OH).sub.2 was first loaded into the quartz kiln at
room temperature. The total weight of P4HB biomass was estimated to
be 281.4 g based on Ca(OH).sub.2 loading. The wt % P4HB in the
mixture was also measured to be 66.7% based on the dry solids which
made the mass of P4HB in the kiln equal to 195 g. The system was
then sealed up and a nitrogen purge of approximately 1500 ml/min
was established. Power was applied to the furnace and the dried
broth+P4HB+Ca(OH).sub.2 was heated up to the target pyrolysis
temperature of 250.degree. C.
[0178] During pyrolysis, the products of the thermal degradation of
biomass+P4HB, GBL, were collected in the condensate traps below the
cooled condensers. Water could be seen to collect initially in each
of the collection bulbs. The majority of the liquified product
(>95%) was collected in the first glass collection bulb. Total
pyrolysis run time was approximately 60 minutes. The weight of the
remaining biomass after pyrolysis was measured to be 11.9 g.
[0179] After the completion of the pyrolysis run, the condensates
from the condensers were collected and weighed. The results showed
that the combined condensate weight was 181 g. Analysis of the
condensate by Karl Fisher moisture analysis and GC-MS showed that
the condensate contained 6.1% water, 0.06% fatty acids with the
balance of the material being GBL products. The GBL product yield
((g of GBL product/g of starting P4HB).times.100%) therefore was
calculated to be approximately 87%. The GC-MS results also showed
that the major impurity in the GBL product was GBL dimer where the
peak area ratio of GBL/GBL dimer was calculated to be 2777. This
was in agreement with the results from the experiment in Example 10
showing that the optimum process conditions for highest GBL purity
were at the 250.degree. C. pyrolysis temperature with the
Ca(OH).sub.2 catalyst. Other impurities such as organosulfur and
amide compounds were also detected as being present in the
condensate by GC-MS. The conversion of the P4HB biomass solid to
liquid ((g of dry Biomass-g Residual biomass/g of dry
biomass).times.100%) was calculated to be 96%. GBL produced was
tested for biobased content according to the standard ASTM-D6866-11
testing protocol and shown to have a biobased content of 99%.
Example 2
Post Purification of Biobased GBL by Distillation, Steam Stripping
and Peroxide Treatment
[0180] This example outlines a procedure for the purification of
biobased GBL liquid prepared from pyrolysis of a genetically
engineered microbe producing poly-4-hydroxybutyrate polymer mixed
with a catalyst as outlined previously in Example 1.
[0181] The GBL purification is a batch process whereby the "crude"
GBL liquid recovered after pyrolysis is first filtered to remove
any solid particulates (typically <1% of the total crude GBL
weight) and then distilled twice to remove compounds contributing
to odor and color.
[0182] Filtration of the crude GBL liquid was carried out on a lab
scale using a Buchner fritted-glass funnel coupled to an Erlenmeyer
receiving flask. Approximately 1 liter of crude GBL was filtered
which resulted in approximately 0.99 liters of recovered GBL
liquid.
[0183] The distillation of the filtered GBL liquid was carried out
using a high vacuum 20 stage glass distillation column. The stage
section of the column was contained inside a silver-coated,
evacuated, glass insulating sleeve in order to minimize any heat
losses from the column during the distillation process. The
distillation was performed under vacuum conditions using a vacuum
pump equipped with a liquid nitrogen cold trap. Typical column
operating pressures during distillation were in the 25 in. Hg
range. Cooling water, maintained at 10.degree. C., was run through
the condenser at the top of the column to assist in the
fractionation of the vapor. The column was also fitted with two
thermocouples: one at the top of the column to monitor vapor
temperature and one at the bottom of the column to monitor the
liquid feed temperature. At the start of the distillation,
approximately 1 liter of filtered GBL liquid was charged into the
bottom of the column, the condenser cooling water and the vacuum
were then turned on. Once the pressure had stabilized, the filtered
GBL liquid was slowly heated using a heating mantle to the boiling
point of GBL (204.degree. C.).
[0184] During the initial stages of the distillation, water
contained in the filtered GBL was removed first and discarded along
with lower boiling impurities. When the water and lower boiling
impurities were completely removed, the GBL liquid feed temperature
increased to the boiling point of GBL. At this stage, the vapor
generated at the top of the column was mostly GBL which was
condensed, collected and reserved for further distillation. When it
was observed that the temperature of the liquid feed increased
quickly above 204.degree. C., the distillation was stopped. The
total amount of GBL liquid recovered in the first distillation was
0.9 liters with a purity of 97%.
[0185] After the remaining feed liquid from the first distillation
was cooled, it was removed from the column and the 0.9 liters of
distilled GBL liquid was added. Along with the distilled GBL
liquid, 203 g (or 20% by weight GBL) of distilled/deionized water
(MILLI-Q.RTM. Water System, Millipore) was added to the bottom of
the column. The addition of the water was found to enhance removal
of many impurities via steam stripping. After addition of the
water, the second distillation was carried out under vacuum as
described previously. The resulting GBL liquid recovered was shown
to be 98% pure.
[0186] Another variation for the second distillation was tried
whereby 1-3% (by weight GBL) of a 30% hydrogen peroxide solution
was added along with the DI water to the previously distilled GBL
liquid. The peroxide acts to oxidize the impurities in the GBL
liquid making them less volatile and thereby easier to separate. To
carry out this distillation, 0.9 liters of previously distilled GBL
liquid were added to the bottom of the distillation column along
with 203 g of DI water and 10.2 g of 30-32% hydrogen peroxide
(Sigma Aldrich). The condenser cooling water and vacuum were
started and the GBL liquid feed heated. The distillation generated
a water fraction first and second transitional fraction prior to
the pure GBL vapor. Both the first and second fractions were
discarded and the pure GBL liquid collected. Analysis of the GBL
liquid by GC-MS showed that is was >99.5% pure with very low
odor and color. To remove additional water, the purified GBL liquid
can be stored over dry molecular sieves (3-4 .ANG. pore size, Sigma
Aldrich) until used.
[0187] Another variation on the above purification steps is to add
DI water and/or 30% hydrogen peroxide solution during the first
distillation stage. Additional purification steps could include
treatment with ozone, ion exchange resin or activated carbon.
Example 3
Production of Biobased-GBL from Purified P4HB Coupled with
Thermolysis
[0188] In this example biomass containing P4HB is produced in a
fermentation process using glucose as the sole carbon feed source
as described above. Following the fermentation, the P4HB is
extracted from the biomass and purified. Suitable methods for
purifying P4HB from biomass are described in for example U.S. Pat.
No. 6,610,764 to Tepha and Metabolix and U.S. Pat. Nos. 7,981,642
and 7,576,173 to Metabolix Inc. Purified P4HB is subjected to a
thermolysis procedure essentially under the same conditions as in
Example 1 and GBL is produced. GBL produced using this approach
should have a biobased content of around 99% when tested according
to the standard ASTM-D6866-11 testing protocol.
Example 4
Production of Biobased-GHB from Purified P4HB Coupled with
Catalyzed Depolymerization
[0189] In this example, GHB is produced directly from purified
biobased P4HB polymer by depolymerizing P4HB in an appropriate
solvent. P4HB polymer is produced and purified as described in
Example 3. The purified polymer is then dissolved in a solvent such
as tetrahydrofuran (THF) and treated with 0.1.M sodium methoxide in
methanol Sufficient sodium methoxide is used to result in
essentially complete degradation of the P4HB to the monomer GHB.
The mixture is stirred at room temperature until the reaction is
complete at which time the reaction mixture is quenched with acid
essentially as described in U.S. Pat. No. 6,623,730. GHB produced
using this approach should have a biobased content of around 99%
when tested according to the standard ASTM-D6866-11 testing
protocol.
Example 5
Production of Biobased P4HB Oligomers from Purified P4HB
[0190] In this example, GHB oligomers with different molecular
weights, from 1,000 Daltons to 50,000 Daltons are produced directly
from purified biobased P4HB polymer. Biobased P4HB polymer is first
produced and purified as described in Example 3. The purified
polymer is then dissolved in a solvent such as Tetrahydrofuran
(THF) and treated with 0.1.M sodium methoxide in methanol.
Sufficient sodium methoxide is used to result in degradation of the
biobased P4Hb polymer to oligomers of the desired molecular weight.
The mixture is stirred at room temperature until the reaction is
complete at which time the reaction mixture is quenched with acid
essentially as described in U.S. Pat. No. 6,623,730. P4HB oligomers
produced using this approach should have a biobased content of
around 99% when tested according to the standard ASTM-D6866-11
testing protocol.
Example 6
Production of Biobased GBL or GHB from Biobased Succinic Acid
[0191] The following example describes the production of GBL from
biobased succinic acid via fermentation of microbial biomass,
isolation of the succinic acid followed by catalytic hydrogenation.
Several methods for producing succinic acid from renewable starting
materials are described in the patent literature (U.S. Pat. Nos.
8,203,021 and 8,246,792; EP application 2,360,137; PCT application
WO2010/092304). All of the patents describe the fermentation of a
genetically modified microbial biomass (such as E coli) to produce
a salt of succinic acid which is then isolated and purified to
succinic acid using techniques well known in the art. The biobased
content as measured by ASTM D6866 of the succinic acid produced by
any of the methods should be at least 98%. To carry out the
hydrogenation of the succinic acid, one can use the liquid phase
procedure as described in U.S. Pat. No. 4,048,196 where a 50 mL
autoclave is charged with 0.3 g of a Cu/Al/Zn oxide catalyst. The
autoclave is then flushed with a 98%/2% nitrogen/hydrogen gas
mixture and heated to 150.degree. C. to reduce the catalyst. A 7%
by weight solution of recovered biobased succinic acid product in
DI water is then introduced into the reactor to a total weight of
10 g. The reactor is further pressurized to 250 bar with pure
H.sub.2 gas and the hydrogenation reaction is allowed to proceed
for 1-2 hours. Upon completion of the reaction, the reactor is
cooled and de-pressurized followed by flushing with nitrogen. The
autoclave contents are discharged and the catalyst separated by
decantation. The catalyst is washed with additional DI water and
the wash is added to the supernatant. An aliquot of supernatant is
filtered and analyzed by HPLC to determine the percent conversion
of succinic acid and the percent yield of GBL on a molar basis.
Alternatively, one could use a vapor phase, catalytic hydrogenation
procedure as described in EP 1,047,687 to convert the succinic acid
to GHB or GBL.
Example 7
Production of Biobased GBL or GHB from Biobased 1,4-butanediol
[0192] The following example describes the production of GBL from
biobased 1,4-butanediol (BDO) via fermentation of microbial
biomass, isolation of the BDO followed by catalytic oxygenation.
Several methods for producing 1,4-butanediol from renewable
starting materials are described in the patent literature (US
patent applications 2009/0075351 and 2010/00304453). The patents
describe the use of a genetically-modified biomass (such as E.
coli, yeast etc.) to produce BDO from starting materials such as
glucose, methanol, syngas (a CO, CO.sub.2, H.sub.2 mixture),
ca-ketoglutarate or succinate. The BDO produced by culturing the
genetically-modified microorganisms is then isolated and purified
using techniques well known in the art. The biobased content as
measured by ASTM D6866 of the purified BDO produced by the above
method should be at least 98%. In order to convert the biobased
1,4-butanediol to GBL a catalytic oxidation is carried out. The BDO
is first heated to 25.degree. C. and is then fed with a pump
through a liquid rotameter to the top of an electrically heated
vaporizer where it is contacted with air fed through a separate
rotameter to the bottom of the vaporizer. The vaporizer is operated
at 150.degree. C. to 200.degree. C. and filled with stainless steel
wool to ensure good heat transfer and efficient vaporization and
mixing of crotonic acid and air. The mixture is then sent to an
electrically heated preheater, also filled with stainless steel
wool, and heated to 250.degree. C. to 300.degree. C. The vapor
stream is sent to a fixed catalyst bed consisting of 1/8 alumina
granules impregnated with vanadium pentoxide (as described in more
detail in Church, J. M. and Bitha, P., "Catalytic air oxidation of
crotonaldehyde to maleic anhydride", I&EC Product Research and
Development, Vol. 2 (1), 1963, p 61-66) contained within a jacketed
reactor vessel. The reactor is heated electrically for start-up and
cooled using circulating heat transfer oil to maintain reactor
conditions. The exit gases are fed to a water cooled cyclone
separator to allow the maleic anhydride and crotonic acid to
condense. Any uncondensed product and still present in the light
gases are then absorbed in a packed tower with circulating cold
water used as direct contact scrubbing liquid. At the end of the
run the liquid product from the cyclone separator and scrubbing
liquid are collected and analyzed to calculate GBL yield (as
percentage of theoretical) and conversion of BDO.
Example 8
Production of Biobased Sodium-GHB from Biobased GBL
[0193] In this example, any of the biobased GBL produced in the
preceding examples are used as the starting material to produce the
sodium salt of gamma-hydroxybutyrate which is a pharmaceutical
compound currently used to treat such medical conditions as
narcolepsy and cataplexy. Biobased GBL (24.4 mol) is slowly added
to a solution of NaOH (25 mol in 2 L of water and 400 ml of
ethanol) with mechanical stirring and the reaction allowed to warm
to reflux for 1 hour. Ethanol is removed by distillation resulting
an aqueous solution containing 70% sodium GHB by weight. GHB
produced using this approach should have a biobased content of
around 99% when tested according to the standard ASTM-D6866-11
testing protocol. By combining biobased GBL with petroleum based
GBL in a ratio of 5:95 GHB having from approximately 5-95% biobased
content can be produced using the procedure described in this
example.
Example 9
Production of a Pharmaceutical Composition Containing Biobased
Sodium-Gamma-Hydroxybutyrate (Na-GHB)
[0194] In this example, a method for preparing a microbially
stable, biobased Na-GHB (as produced in Ex. 8) pharmaceutical
formulation is described (see U.S. Pat. No. 8,263,650). To prepare
a microbially stable pharmaceutical formulation, Na-GHB is
dissolved in DI water to a concentration of about 500 mg/ml. The pH
is adjusted with malic acid, HCl, citric acid or other acids to a
value from 7.3-8.5. These acids also act as buffers to maintain the
pH within the optimum range to prevent conversion of the GHB to GBL
and to prevent microbial growth during storage.
Example 10
Continuous Production of a Pharmaceutical Composition Containing
Biobased GHB
[0195] Biobased GBL produced as described in the above examples can
be used in a continuous process to produce GHB for pharmaceutical
applications as described in PCT WO2012051473 to Norac Pharma.
Example 11
Compositions Containing Biobased GHB Moieties for Enhancing
Treatment of Patients
[0196] Biobased GBL or GHB is used for making enhanced compositions
comprising GHB moieties for treating patients essentially as
described in U.S. Pat. No. 7,572,605B2.
Example 12
Compositions Containing Biobased Deuterated Na-GHB
[0197] Biobased Na-GHB having one or more hydrogen atoms replaced
with deuterium atoms can be prepared by starting with biobased GBL
as prepared in Examples 1-7 and following the procedure described
in Patent Application No. US2012/0122952 assigned to Concert
Pharmaceuticals. Biobased GBL is first converted to the butyl ester
by reaction with butanol using an acid catalyst. The t-butyl ester
of GBL is then reacted in deuterated methanol in the presence of
potassium carbonate to effect a hydrogen-deuterium atom exchange.
After the hydrogen-deuterium exchange is complete, the compound is
saponified with sodium hydroxide to form a biobased deuterated
sodium oxybate. Alternatively, one could use deuterated feedstocks
(sugar, acetic acid or D.sub.2O) to make the starting succinic
acid, 1,4-butanediol or GBL materials which are then converted to
Na-GHB as described in the previous examples.
Example 13
Compositions Containing Biobased Fluorinated Na-GHB
[0198] International Patent Application No. WO2102/142162 outlines
a method and materials for fluorinating hydroxyl organic compounds
such as pharmaceutical intermediates or precursors. The method can
be applied to biobased sodium oxybate as prepared in Example 8.
Example 14
Generation of Immediate Release, Biobased Sodium Oxybate Solid
Dosage Formulation
[0199] U.S. Patent Application Publication No. US20110111027
assigned to Jazz Pharmaceuticals describes a solid dosage form
containing sodium oxybate which when taken orally is capable of
quickly releasing 90% of the gamma-hydroxybutyrate active
pharmaceutical in less than 1 hour similar to the effect when
administering liquid sodium oxybate. The formulation contains
Na-GHB (70-90% by weight), a binder e.g. hydroxypropyl cellulose
(1-10% by weight), a lubricant e.g. magnesium stearate (0.5-5% by
weight) and a surfactant e.g. sodium lauryl sulfate (0.5-3% by
weight). The ingredients can be combined either in a dry or wet
granulation procedure and then pressed into a tablet. In the wet
procedure ethanol was used to first dissolve the hydroxypropyl
cellulose binder. Similar formulations could also be made by
substituting biobased sodium oxybate as prepared in Example 8 into
the immediate release formulation as described above to form a
biobased, immediate release, sodium oxybate solid dosage
tablet.
Example 15
Controlled Release Solid Dosage Forms of Biobased Ultra High Purity
Sodium Oxybate
[0200] U.S. Patent Application Publication No. US20120076865
assigned to Jazz Pharmaceuticals describes controlled release
dosage forms for water soluble and hygroscopic drugs such as sodium
oxybate. The formulation as describes includes both an immediate
release coating of sodium oxybate and a controlled released solid
core of sodium oxybate. The core is composed of Na-GHB (90-100% by
weight) and a polymer binder such as hydroxypropylene cellulose or
ethyl cellulose (1-10% by weight) that are used for preparing the
solid tablets. Other components may be added to the controlled
release core such as lubricants, surfactants, plasticizers,
excipients, compression aids or other fillers.
[0201] The core is formed by wet granulation, roller compaction or
direct compression. Once the core is formed, it is then coated to
facilitate the controlled release of the sodium oxybate in the GI
tract as well as to retain the integrity of the unit dosage form.
The coating is a blend of a polymer e.g. cellulose polymers (50-80%
by weight), a pore former which modifies the permeability of the
coating e.g. hydroxypropyl cellulose, sugars or organic acids and
other fillers or additives. It is applied to the core at about
2.5-7.5% by weight of the total tablet weight. The thickness of the
coating also imparts control of the rate of release of the sodium
oxybate from the core and can be varied to modulate the delivery of
the pharmaceutical. The release profile sodium oxybate from the
coated tablet was shown to be in the range of 6-8 hours or
more.
[0202] Prior to administering the coated tablet, it can also be
coated with an immediate release film containing sodium oxybate as
described in Example 14. In this way the tablet delivers a
predetermined concentration of sodium oxybate within the first hour
then maintains a sustained release profile over the next 6-8 hours.
Similar controlled release formulations could be made by
substituting the ultra high purity, biobased sodium oxybate
prepared in Example 8 into the formulation as described above.
Thereby making a biobased, controlled release, sodium oxybate solid
dosage tablet.
Example 16
Synthesis of Deuterated P4HB Using D.sub.2O or Deuterated Glucose
as the Deuterium Source
[0203] Deuterium oxide (D.sub.2O) and glucose-1,2,3,4,5,6, 6-d7
were purchased from Sigma Aldrich. Two solutions of minimal salts
media (MSM) were prepared. One solution used D.sub.2O as the source
for all water components, except for a small addition of trace
salts solution which added a 1:1000 H.sub.2O component to the
deuterated solution. The second solution contained only H.sub.2O.
In addition, a deuterated LB medium and 500 g/L glucose solution in
D.sub.2O were used.
[0204] The homopolymer P4HB strain MBX4743 was chosen for this
experiment. MBX4743 was inoculated into LB H.sub.2O medium from a
glycerol stock, and incubated overnight at 250 RPM and 37.degree.
C. One mL of the overnight culture was subcultured into 2 mL of
both LB-D.sub.2O and LB-H.sub.2O, and incubated in the shaker for 2
hours at 37.degree. C. The LB-D.sub.2O overnight culture was used
to subculture into D.sub.2O minimal salts media, while the
LB-H.sub.2O culture was used to sub-culture into H.sub.2O minimal
salts media. All subcultures were incubated in the shaker for 3
hours at 37.degree. C. (FIG. 1). The H.sub.2O-MSM culture was used
to inoculate the control (Table 1, condition 1), while the
D.sub.2O-MSM culture was used to inoculate all other conditions
(Table 1).
TABLE-US-00001 TABLE 1 Fermentation medium conditions Condition
Number Medium Glucose Fed (mg) 1 100% H.sub.2O, MSM 756 unlabeled
glucose 2 50% D.sub.2O + 50% H.sub.2O, MSM 689 unlabeled glucose 3
75% D.sub.2O + 25% H.sub.2O, MSM 376 unlabeled glucose 4 100%
D.sub.2O, MSM 220 unlabeled glucose 5 25% D.sub.2O + 75% H.sub.2O,
MSM 49 heavy glucose + 69 unlabeled glucose 6 50% D.sub.2O + 50%
H.sub.2O, MSM 378 heavy glucose 7 100% D.sub.2O, MSM 200 heavy
glucose
[0205] Seven fermentation medium conditions with different amounts
of D.sub.2O and labeled glucose were prepared (Table 1). Four
hundred .mu.L of MSM cultures were used to inoculate 24 wells in
the MICRO24 reactor (Table 2). The pH was kept at 6.9 via an
NH.sub.4OH bubbler and the dissolved oxygen (DO) was maintained at
20% via a pure oxygen feed. The fermentation was allowed to proceed
for 42 hours. Glucose feeding occurred at the discretion of the
operator with an attempt to maintain the glucose concentration at
30 g/L. Unlabeled 500 g/L glucose in H.sub.2O was used to feed the
control (condition 1). Unlabeled 500 g/L glucose in D.sub.2O was
used to feed conditions 2, 3, 4, and 7. Different amounts of
labeled 500 g/L glucose-1, 2, 3, 4, 5, 6, 6-d7 ("heavy glucose") in
D.sub.2O were used in the conditions 5 through 7.
TABLE-US-00002 TABLE 2 The conditions of each well in the 24 wells
of the MICRO24 cassette. The numbers in each cell correspond to the
fermentation medium conditions in Table 1 (1 through 7). Column Row
C-1 C-2 C-3 C-4 C-5 C-6 A 1 1 4 4 4 5 B 1 1 4 4 7 6 C 1 1 3 3 3 3 D
1 1 2 2 2 2
[0206] Wells containing the same condition were pooled together. A
sample of broth from each condition was centrifuged down, washed
with H.sub.2O, freeze dried, and converted to the butyl-ester form
through butanolysis. The remaining broth from each condition was
used for polymer extraction and purification for .sup.1H-NMR
analysis.
[0207] Results
[0208] After 42 hours of fermentation in the MICRO24, all
conditions with the exception of condition 7 reached high cell
density with greater than 50% P4HB accumulation (Table 3).
TABLE-US-00003 TABLE 3 Cell growth in the MICRO24 Final Condition
Biomass Number Medium Glucose Fed (mg) Titer (g/L) 1 100% H.sub.2O,
MSM 756 unlabeled glucose 32.6 2 50% D.sub.2O + 50% H.sub.2O, 689
unlabeled glucose 26.9 MSM 3 75% D.sub.2O + 25% H.sub.2O, 376
unlabeled glucose 23.8 MSM 4 100% D.sub.2O, MSM 220 unlabeled
glucose 3.5 5 25% D.sub.2O + 75% H.sub.2O, 49 heavy glucose + 69
13.1 MSM unlabeled glucose 6 50% D.sub.2O + 50% H.sub.2O, 378 heavy
glucose 13.6 MSM 7 100% D.sub.2O, MSM 200 heavy glucose No
growth
[0209] The fermentation samples were analyzed via GC-MS for
isotopomer distribution. A typical GC chromatogram of P4HB shows
two dominant peaks due to P4HB: butyl-4-chlorobutyrate at 7.68 min
and butyl-4-butoxybutyrate at 10.18 min. Either of the two peaks
could be used to determine the molecular weight distribution of
4HB, the monomer repeat unit of P4HB. The peak that correlated with
butyl-4-butoxybutyrate was chosen for further analysis. A typical
fragmentation pattern of butyl-4-butoxybutyrate shows the base ion
at m/z 87 and the parent ion at m/z 159. Both patterns can be used
to determine the isotopomer distribution but the parent pattern at
m/z 159 was chosen for further analysis for simplicity.
[0210] Results of GC-MS at m/z 159 for the six conditions are
summarized in Table 4.
TABLE-US-00004 TABLE 4 GC-MS results. The m/z of 159 corresponds to
the parent ion without any deuterium. The m/z of 165 corresponds to
the ion with six deuteriums. The data were corrected for the
presence of naturally occurring .sup.13C (1.07%) from the glucose
in the fermentation medium and the butanol in the butanolysis
reaction. The contribution due to the natural abundance of
deuterium (0.0115%) is small and thus neglected. m/z Number of
Percent of Condition 159 160 161 162 163 164 165 deuterium
deuteration Number (0 D) (1 D) (2 D) (3 D) (4 D) (5 D) (6 D) 166
at4HB at 4HB 1 97% 0% 3% 2 4% 18% 30% 28% 15% 4% 1% 2.47 41% 3 1%
4% 16% 30% 30% 16% 4% 3.46 58% 4 2% 0% 1% 7% 24% 41% 24% 1% 4.79
80% 5 19% 28% 31% 16% 5% 1% 1.63 27% 6 2% 2% 9% 23% 32% 24% 8% 1%
3.90 65%
[0211] Since 4HB in the polymer form has six hydrogen atoms, seven
molecular weight species are theoretically possible depending on
the number of hydrogen atoms that are substituted with deuterium
(from zero (m/z of 159) to six deuteriums (m/z of 165)).
[0212] The GC-MS results indicated that the extent of deuterium
incorporation into P4HB varied, depending on the fermentation
conditions that were used. The results of conditions 2 through 5,
in which D.sub.2O was the only source of deuterium, demonstrated
that deuterium can be incorporated into P4HB using D.sub.2O as the
deuteration source. In addition, the extent of incorporation varied
with the amount of D.sub.2O that was added to the medium. The use
of deuterated glucose also increased the degree of deuteration
(conditions 6 and 7).
[0213] When 100% D.sub.2O was used (condition 5), the most abundant
4HB species obtained was the five-deuterium (5D) species with 41%
abundance. 4HB labeled with six deuterium atoms (6D) could also be
obtained (24% abundance). The average number of deuterium atoms
that could be incorporated using 100%/o D.sub.2O was 4.79
substitutions per 4HB monomer unit, resulting in 80%
deuteration.
[0214] The samples of conditions 1 and 5 were analyzed via
.sup.1H-NMR to independently confirm the deuteration results of
GC-MS. The multiplet patterns of the peaks at the C-2, C-3, and C-4
positions of P4HB confirmed the incorporation of deuterium into
P4HB. The C-4 peak at 4.109 ppm shows a triplet with the intensity
of 1:2:1, the C-3 peak at 1.955 ppm shows a quintet with the
intensity of 1:4:6:4:1, and the C-2 peak at 2.383 ppm shows a
triplet with the intensity of 1:2:1.
[0215] The .sup.1H-NMR spectrum of condition 5 shows a different
pattern because the incorporation of deuterium changes the
multiplet pattern: the C-4 peak shows a doublet indicating that at
least one of the hydrogen atoms at the C-3 position are replaced
with deuterium. The C-3 peak is a doublet indicating that most of
the hydrogen atoms at the C-2 and C-4 positions are replaced with
deuterium (three of the four coupled atoms at the C-2 and C-4
positions are substituted). The C-2 peak is also a doublet
indicating that at least one of the hydrogen atoms at C-3 are
replaced with deuterium.
[0216] The .sup.1H-NMR spectrum of condition 5 is qualitatively
consistent with the distribution of the molecular weight species as
determined by GC-MS: the D5 species and D6 species would not
produce any peaks in .sup.1H-NMR. The most abundant species with
the abundance of 41% was D4 species which contains only two
hydrogen atoms. There are six isotopomers of the D4 species. Each
of the six isotopomers has a different proton splitting pattern.
The peak at each carbon position is a superposition of the peaks
from the six isotopomers.
[0217] Since there exist only a doublet and a singlet due to the D4
species, the peak at each position can be a three-peak multiplet,
as opposed to a triplet which differs in intensity pattern and
chemical shift. Alternatively, a singlet or a doublet will dominate
at each position if any of the isotopomers is the most dominant.
The doublet pattern was dominant at all the three carbon positions
indicating that isotopomers 1 and 4 were probably the most
dominant.
* * * * *