U.S. patent application number 11/062054 was filed with the patent office on 2005-09-22 for botulinum toxin pharmaceutical composition with enhanced potency.
This patent application is currently assigned to ALLERGAN, INC.. Invention is credited to Hunt, Terrence J..
Application Number | 20050208076 11/062054 |
Document ID | / |
Family ID | 46281488 |
Filed Date | 2005-09-22 |
United States Patent
Application |
20050208076 |
Kind Code |
A1 |
Hunt, Terrence J. |
September 22, 2005 |
Botulinum toxin pharmaceutical composition with enhanced
potency
Abstract
A botulinum toxin pharmaceutical formulation free of animal
derived proteins, comprising a botulinum toxin and a recombinant
albumin, suitable for therapeutic administration to a human
patient, and methods for treating patients with various diseases
and afflictions with the formulation.
Inventors: |
Hunt, Terrence J.; (Corona,
CA) |
Correspondence
Address: |
STEPHEN DONOVAN
ALLERGAN, INC.
2525 Dupont Drive
Irvine
CA
92612
US
|
Assignee: |
ALLERGAN, INC.
Irvine
CA
|
Family ID: |
46281488 |
Appl. No.: |
11/062054 |
Filed: |
February 17, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11062054 |
Feb 17, 2005 |
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10288738 |
Nov 5, 2002 |
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10288738 |
Nov 5, 2002 |
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10047058 |
Jan 14, 2002 |
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10047058 |
Jan 14, 2002 |
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09500147 |
Feb 8, 2000 |
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Current U.S.
Class: |
424/239.1 ;
514/15.2; 514/17.7; 514/2.8 |
Current CPC
Class: |
A61K 47/36 20130101;
A61K 9/0019 20130101; A61K 47/183 20130101; Y02A 50/30 20180101;
Y02A 50/469 20180101; A61K 9/19 20130101; A61K 38/4893 20130101;
A61P 21/00 20180101 |
Class at
Publication: |
424/239.1 ;
514/006 |
International
Class: |
A61K 039/08; A61K
038/16 |
Claims
I claim:
1-19. (canceled)
20. A process for making a botulinum toxin pharmaceutical
composition with an enhanced potency, the process comprising the
step of combining a botulinum toxin and a recombinant human serum
albumin, thereby obtaining a botulinum toxin pharmaceutical
composition with an enhanced potency.
21. The process of claim 20 further comprising the step, before the
combining step, of obtaining a botulinum toxin.
22. The process of claim 21 further comprising the step, before the
combining step, of obtaining a recombinant albumin.
23. the process of claim 20, wherein the botulinum toxin
pharmaceutical composition has an enhanced potency with regard to a
reference botulinum toxin pharmaceutical composition.
24. the process of claim 23, wherein the reference botulinum toxin
pharmaceutical composition contains a botulinum toxin, sodium
chloride and human serum albumin.
25. the process of claim 23, wherein the botulinum toxin
pharmaceutical composition has a potency which is from at least 5%
and up to 40% greater than the potency of the reference botulinum
toxin pharmaceutical composition.
26. A process for making a botulinum toxin pharmaceutical
composition, with an enhanced potency the process comprising the
steps of: (a) obtaining a botulinum toxin; (b) obtaining a
recombinant albumin and; (c) combining the botulinum toxin and the
recombinant human serum albumin to thereby obtain a botulinum toxin
pharmaceutical composition with an enhanced potency.
27. A botulinum toxin pharmaceutical composition made by the
process of claim 20.
28. A botulinum toxin pharmaceutical composition made by the
process of claim 26.
Description
CROSS REFERENCE
[0001] This application is a continuation in part of application
Ser. No. 10/047,058, filed Jan. 14, 2002, which is a continuation
in part of application Ser. No. 09/500,147, filed Feb. 8, 2000. The
entire contents of these prior patent applications are incorporated
herein by reference.
BACKGROUND
[0002] The present invention relates to Clostridial toxin
pharmaceutical compositions. In particular, the present invention
relates to botulinum toxin pharmaceutical compositions and uses
thereof.
[0003] A pharmaceutical composition is a formulation which contains
at least one active ingredient (such as a Clostridial toxin) as
well as, for example, one or more excipients, buffers, carriers,
stabilizers, preservatives and/or bulking agents, and is suitable
for administration to a patient to achieve a desired diagnostic
result or therapeutic effect. The pharmaceutical compositions
disclosed herein have diagnostic, therapeutic and/or research
utility in patients such as humans, as well in, for example,
canine, equine, bovine and porcine mammalian species patients, and
in non-mammalian avian species patients.
[0004] For storage stability and convenience of handling, a
pharmaceutical composition can be formulated as a lyophilized (i.e.
freeze dried) or vacuum dried powder which can be reconstituted
with a suitable fluid, such as saline or water, prior to
administration to a patient. Alternately, the pharmaceutical
composition can be formulated as an aqueous solution or suspension.
A pharmaceutical composition can contain a proteinaceous active
ingredient. Unfortunately, a protein active ingredient can be very
difficult to stabilize (i.e. maintained in a state where loss of
biological activity is minimized), resulting therefore in a loss of
protein and/or loss of protein activity during the formulation,
reconstitution (if required) and during the period of storage prior
to use of a protein containing pharmaceutical composition.
Stability problems can occur because of protein denaturation,
degradation, dimerization, and/or polymerization. Various
excipients, such as albumin and gelatin have been used with
differing degrees of success to try and stabilize a protein active
ingredient present in a pharmaceutical composition. Additionally,
cryoprotectants such as alcohols have been used to reduce protein
denaturation under the freezing conditions of lyophilization.
[0005] Albumin
[0006] Albumins are small, abundant plasma proteins. Human serum
albumin has a molecular weight of about 69 kiloDaltons (kD) and has
been used as a non-active ingredient in a pharmaceutical
composition where it can serve as a bulk carrier and stabilizer of
certain protein active ingredients present in a pharmaceutical
composition.
[0007] The stabilization function of albumin in a pharmaceutical
composition can be present both during the multi-step formulation
of the pharmaceutical composition and upon the later reconstitution
of the formulated pharmaceutical composition. Thus, stability can
be imparted by albumin to a proteinaceous active ingredient in a
pharmaceutical composition by, for example, (1) reducing adhesion
(commonly referred to as "stickiness") of the protein active
ingredient to surfaces, such as the surfaces of laboratory
glassware, vessels, to the vial in which the pharmaceutical
composition is reconstituted and to the inside surface of a syringe
used to inject the pharmaceutical composition. Adhesion of a
protein active ingredient to surfaces can lead to loss of active
ingredient and to denaturation of the remaining retained protein
active ingredient, both of which reduce the total activity of the
active ingredient present in the pharmaceutical composition, and;
(2) reducing denaturation of the active ingredient which can occur
upon preparation of a low dilution solution of the active
ingredient.
[0008] As well as being able to stabilize a protein active
ingredient in a pharmaceutical composition, human serum albumin
also has the advantage of generally negligible immunogenicity when
injected into a human patient. A compound with an appreciable
immunogenicity can cause the production of antibodies against it
which can lead to an anaphylactic reaction and/or to the
development of drug resistance, with the disease or disorder to be
treated thereby becoming potentially refractory to the
pharmaceutical composition which has an immunogenic component.
[0009] Unfortunately, despite its known stabilizing effect,
significant drawbacks exist to the use of human serum albumin in a
pharmaceutical composition. For example human serum albumins are
expensive and increasingly difficult to obtain. Furthermore, blood
products such as albumin, when administered to a patient can
subject the patient to a potential risk of receiving blood borne
pathogens or infectious agents. Thus, it is known that the
possibility exists that the presence of albumin in a pharmaceutical
composition can result in inadvertent incorporation of infectious
elements into the pharmaceutical composition. For example, it has
been reported that use of human serum albumin may transmit prions
into a pharmaceutical composition. A prion is a proteinaceous
infectious particle which is hypothesized to arise as an abnormal
conformational isoform from the same nucleic acid sequence which
makes the normal protein. It has been further hypothesized that
infectivity resides in a "recruitment reaction" of the normal
isoform protein to the prion protein isoform at a post
translational level. Apparently the normal endogenous cellular
protein is induced to misfold into a pathogenic prion conformation.
Significantly, several lots of human serum albumin have been
withdrawn from distribution upon a determination that a blood donor
to a pool from which the albumin was prepared was diagnosed with
Creutzfeldt-Jacob disease.
[0010] Creutzfeldt-Jacob disease (sometimes characterized as
Alzheimer's disease on fast forward) is a rare neurodegenerative
disorder of human transmissible spongiform encephalopathy where the
transmissible agent is apparently an abnormal isoform of a prion
protein. An individual with Creutzfeldt-Jacob disease can
deteriorate from apparent perfect health to akinetic mutism within
six months. Possible iatrogenic transmission of Creutzfeldt-Jacob
disease by human serum albumin transfusion has been reported and it
has been speculated that sufficient protection against
Creutzfeldt-Jacob disease transmission is not provided by the usual
methods of human serum albumin preparation which methods include
disposal of blood cellular elements and heating to 60 degrees C.
for 10 hours. Thus, a potential risk may exist of acquiring a prion
mediated disease, such as Creutzfeldt-Jacob disease, from the
administration of a pharmaceutical composition which contains human
plasma protein concentrates, such as serum albumin.
[0011] Gelatin has been used in some protein active ingredient
pharmaceutical compositions as an albumin substitute. Notably,
gelatin is a animal derived protein and therefore carries the same
risk of potential infectivity which may be possessed by human serum
albumin. Hence, it is desirable to find a substitute for human
serum albumin which is not a blood fraction, and preferably, the
albumin substitute is not gelatin and is not derived from any
animal (i.e. mammalian) source.
[0012] Botulinum Toxin
[0013] The anaerobic, gram positive bacterium Clostridium botulinum
produces a potent polypeptide neurotoxin, botulinum toxin, which
causes a neuroparalytic illness in humans and animals referred to
as botulism. Clostridium botulinum and its spores are commonly
found in soil and the bacterium can grow in improperly sterilized
and sealed food containers of home based canneries, which are the
cause of many of the cases of botulism. The effects of botulism
typically appear 18 to 36 hours after eating the foodstuffs
infected with a Clostridium botulinum culture or spores. The
botulinum toxin can apparently pass unattenuated through the lining
of the gut and attack peripheral motor neurons. Symptoms of
botulinum toxin intoxication can progress from difficulty walking,
swallowing, and speaking to paralysis of the respiratory muscles
and death.
[0014] Botulinum toxin type A is the most lethal natural biological
agent known to man. About 50 picograms of botulinum toxin (purified
neurotoxin complex) type A is a LD.sub.50 in mice. Interestingly,
on a molar basis, botulinum toxin type A is 1.8 billion times more
lethal than diphtheria, 600 million times more lethal than sodium
cyanide, 30 million times more lethal than cobrotoxin and 12
million times more lethal than cholera. Singh, Critical Aspects of
Bacterial Protein Toxins, pages 63-84 (chapter 4) of Natural Toxins
II, edited by B. R. Singh et al., Plenum Press, New York (1976)
(where the stated LD.sub.50 of botulinum toxin type A of 0.3 ng
equals 1 U is corrected for the fact that about 0.05 ng of
BOTOX.RTM. equals 1 unit). One unit (U) of botulinum toxin is
defined as the LD.sub.50 upon intraperitoneal injection into female
Swiss Webster mice weighing 18-20 grams each. In other words, one
unit of botulinum toxin is the amount of botulinum toxin that kills
50% of a group of female Swiss Webster mice. Seven generally
immunologically distinct botulinum neurotoxins have been
characterized, these being respectively botulinum neurotoxin
serotypes A, B, C.sub.1, D, E, F, and G, each of which is
distinguished by neutralization with type-specific antibodies. The
different serotypes of botulinum toxin vary in the animal species
that they affect and in the severity and duration of the paralysis
they evoke. For example, it has been determined that botulinum
toxin type A is 500 times more potent, as measured by the rate of
paralysis produced in the rat, than is botulinum toxin type B.
Additionally, botulinum toxin type B has been determined to be
non-toxic in primates at a dose of 480 U/kg which is about 12 times
the primate LD.sub.50 for botulinum toxin type A. The botulinum
toxins apparently bind with high affinity to cholinergic motor
neurons, are translocated into the neuron and block the presynaptic
release of acetylcholine.
[0015] Botulinum toxins have been used in clinical settings for the
treatment of neuromuscular disorders characterized by hyperactive
skeletal muscles. Botulinum toxin type A was approved by the U.S.
Food and Drug Administration in 1989 for the treatment of essential
blepharospasm, strabismus and hemifacial spasm in patients over the
age of twelve. Clinical effects of peripheral injection (i.e.
intramuscular or subcutaneous) botulinum toxin type A are usually
seen within one week of injection, and often within a few hours
after injection. The typical duration of symptomatic relief (i.e.
flaccid muscle paralysis) from a single intramuscular injection of
botulinum toxin type A can be about three months to about six
months.
[0016] Although all the botulinum toxins serotypes apparently
inhibit release of the neurotransmitter acetylcholine at the
neuromuscular junction, they do so by affecting different
neurosecretory proteins and/or cleaving these proteins at different
sites. Botulinum toxin A is a zinc endopeptidase which can
specifically hydrolyze a peptide linkage of the intracellular,
vesicle associated protein SNAP-25. Botulinum type E also cleaves
the 25 kiloDalton (kD) synaptosomal associated protein (SNAP-25),
but targets different amino acid sequences within this protein, as
compared to botulinum toxin type A. Botulinum toxin types B, D, F
and G act on vesicle-associated protein (VAMP, also called
synaptobrevin), with each serotype cleaving the protein at a
different site. Finally, botulinum toxin type C.sub.1 has been
shown to cleave both syntaxin and SNAP-25. These differences in
mechanism of action may affect the relative potency and/or duration
of action of the various botulinum toxin serotypes.
[0017] Regardless of serotype, the molecular mechanism of toxin
intoxication appears to be similar and to involve at least three
steps or stages. In the first step of the process, the toxin binds
to the presynaptic membrane of the target neuron through a specific
interaction between the heavy chain (H chain) and a cell surface
receptor; the receptor is thought to be different for each serotype
of botulinum toxin and for tetanus toxin. The carboxyl end segment
of the H chain, H.sub.C, appears to be important for targeting of
the toxin to the cell surface.
[0018] In the second step, the toxin crosses the plasma membrane of
the poisoned cell. The toxin is first engulfed by the cell through
receptor-mediated endocytosis, and an endosome containing the toxin
is formed. The toxin then escapes the endosome into the cytoplasm
of the cell. This last step is thought to be mediated by the amino
end segment of the H chain, H.sub.N, which triggers a
conformational change of the toxin in response to a pH of about 5.5
or lower. Endosomes are known to possess a proton pump which
decreases intra endosomal pH. The conformational shift exposes
hydrophobic residues in the toxin, which permits the toxin to embed
itself in the endosomal membrane. The toxin then translocates
through the endosomal membrane into the cytosol.
[0019] The last step of the mechanism of botulinum toxin activity
appears to involve reduction of the disulfide bond joining the H
and L chain. The entire toxic activity of botulinum and tetanus
toxins is contained in the L chain of the holotoxin; the L chain is
a zinc (Zn++) endopeptidase which selectively cleaves proteins
essential for recognition and docking of
neurotransmitter-containing vesicles with the cytoplasmic surface
of the plasma membrane, and fusion of the vesicles with the plasma
membrane. Tetanus neurotoxin, botulinum toxin B, D, F, and G cause
degradation of synaptobrevin (also called vesicle-associated
membrane protein (VAMP)), a synaptosomal membrane protein. Most of
the VAMP present at the cytosolic surface of the synaptic vesicle
is removed as a result of any one of these cleavage events. Each
toxin specifically cleaves a different bond.
[0020] The molecular weight of the botulinum toxin protein
molecule, for all seven of the known botulinum toxin serotypes, is
about 150 kD. Interestingly, the botulinum toxins are released by
Clostridial bacterium as complexes comprising the 150 kD botulinum
toxin protein molecule along with associated non-toxin proteins.
Thus, the botulinum toxin type A complex can be produced by
Clostridial bacterium as 900 kD, 500 kD and 300 kD forms. Botulinum
toxin types B and C.sub.1 are apparently produced as only a 500 kD
complex. Botulinum toxin type D is produced as both 300 kD and 500
kD complexes. Finally, botulinum toxin types E and F are produced
as only approximately 300 kD complexes. The complexes (i.e.
molecular weight greater than about 150 kD) are believed to contain
a non-toxin hemagglutinin protein and a non-toxin and non-toxic
nonhemagglutinin protein. These two non-toxin proteins (which along
with the botulinum toxin molecule can comprise the relevant
neurotoxin complex) may act to provide stability against
denaturation to the botulinum toxin molecule and protection against
digestive acids when toxin is ingested. Additionally, it is
possible that the larger (greater than about 150 kD molecular
weight) botulinum toxin complexes may result in a slower rate of
diffusion of the botulinum toxin away from a site of intramuscular
injection of a botulinum toxin complex. The toxin complexes can be
dissociated into toxin protein and hemagglutinin proteins by
treating the complex with red blood cells at pH 7.3. The toxin
protein has a marked instability upon removal of the hemagglutinin
protein.
[0021] All the botulinum toxin serotypes are made by Clostridium
botulinum bactena as inactive single chain proteins which must be
cleaved or nicked by proteases to become neuroactive. The bacterial
strains that make botulinum toxin serotypes A and G possess
endogenous proteases and serotypes A and G can therefore be
recovered from bacterial cultures in predominantly their active
form. In contrast, botulinum toxin serotypes C.sub.1, D, and E are
synthesized by nonproteolytic strains and are therefore typically
unactivated when recovered from culture. Serotypes B and F are
produced by both proteolytic and nonproteolytic strains and
therefore can be recovered in either the active or inactive form.
However, even the proteolytic strains that produce, for example,
the botulinum toxin type B serotype only cleave a portion of the
toxin produced. The exact proportion of nicked to unnicked
molecules depends on the length of incubation and the temperature
of the culture. Therefore, a certain percentage of any preparation
of, for example, the botulinum toxin type B toxin is likely to be
inactive, possibly accounting for the known significantly lower
potency of botulinum toxin type B as compared to botulinum toxin
type A. The presence of inactive botulinum toxin molecules in a
clinical preparation will contribute to the overall protein load of
the preparation, which has been linked to increased antigenicity,
without contributing to its clinical efficacy. Additionally, it is
known that botulinum toxin type B has, upon intramuscular
injection, a shorter duration of activity and is also less potent
than botulinum toxin type A at the same dose level.
[0022] In vitro studies have indicated that botulinum toxin
inhibits potassium cation induced release of both acetylcholine and
norepinephrine from primary cell cultures of brainstem tissue.
Additionally, it has been reported that botulinum toxin inhibits
the evoked release of both glycine and glutamate in primary
cultures of spinal cord neurons and that in brain synaptosome
preparations botulinum toxin inhibits the release of each of the
neurotransmitters acetylcholine, dopamine, norepinephrine, CGRP and
glutamate.
[0023] High quality crystalline botulinum toxin type A can be
produced from the Hall A strain of Clostridium botulinum with
characteristics of .gtoreq.3.times.10.sup.7 U/mg, an
A.sub.260/A.sub.278 of less than 0.60 and a distinct pattern of
banding on gel electrophoresis. The known Schantz process can be
used to obtain crystalline botulinum toxin type A, as set forth in
Schantz, E. J., et al, Properties and use of Botulinum toxin and
Other Microbial Neurotoxins in Medicine, Microbiol Rev. 56: 80-99.
(1992). Generally, the botulinum toxin type A complex can be
isolated and purified from an anaerobic fermentation by cultivating
Clostridium botulinum type A in a suitable medium. Raw toxin can be
harvested by precipitation with sulfuric acid and concentrated by
ultramicrofiltration. Purification can be carried out by dissolving
the acid precipitate in calcium chloride. The toxin can then be
precipitated with cold ethanol. The precipitate can be dissolved in
sodium phosphate buffer and centrifuged. Upon drying there can then
be obtained approximately 900 kD crystalline botulinum toxin type A
complex with a specific potency of 3.times.10.sup.7 LD.sub.50 U/mg
or greater. This known process can also be used, upon separation
out of the non-toxin proteins, to obtain pure botulinum toxins,
such as for example: purified botulinum toxin type A with an
approximately 150 kD molecular weight with a specific potency of
1-2.times.10.sup.8 LD.sub.50 U/mg or greater; purified botulinum
toxin type B with an approximately 156 kD molecular weight with a
specific potency of 1-2.times.10.sup.8 LD.sub.50 U/mg or greater,
and; purified botulinum toxin type F with an approximately 155 kD
molecular weight with a specific potency of 1-2.times.10.sup.7
LD.sub.50 U/mg or greater.
[0024] Already prepared and purified botulinum toxins and toxin
complexes suitable for preparing pharmaceutical formulations can be
obtained from List Biological Laboratories, Inc., Campbell, Calif.;
the Centre for Applied Microbiology and Research, Porton Down,
U.K.; Wako (Osaka, Japan), as well as from Sigma Chemicals of St
Louis, Mo.
[0025] It has been reported that BoNt/A has been used in clinical
settings as follows:
[0026] (1) about 75-125 units of BOTOX.RTM..sup.1 per intramuscular
injection (multiple muscles) to treat cervical dystonia; 1
Available from Allergan, Inc., of Irvine, Calif. under the
tradename BOTOX.RTM..
[0027] (2) 5-10 units of BOTOX.RTM. per intramuscular injection to
treat glabellar lines (brow furrows) (5 units injected
intramuscularly into the procerus muscle and 10 units injected
intramuscularly into each corrugator supercilii muscle);
[0028] (3) about 30-80 units of BOTOX.RTM. to treat constipation by
intrasphincter injection of the puborectalis muscle;
[0029] (4) about 1-5 units per muscle of intramuscularly injected
BOTOX.RTM. to treat blepharospasm by injecting the lateral
pre-tarsal orbicularis oculi muscle of the upper lid and the
lateral pre-tarsal orbicularis oculi of the lower lid.
[0030] (5) to treat strabismus, extraocular muscles have been
injected intramuscularly with between about 1-5 units of
BOTOX.RTM., the amount injected varying based upon both the size of
the muscle to be injected-and the extent of muscle paralysis
desired (i.e. amount of diopter correction desired).
[0031] (6) to treat upper limb spasticity following stroke by
intramuscular injections of BOTOX.RTM. into five different upper
limb flexor muscles, as follows:
[0032] (a) flexor digitorum profundus: 7.5 U to 30 U
[0033] (b) flexor digitorum sublimus: 7.5 U to 30 U
[0034] (c) flexor carpi ulnaris: 10 U to 40 U
[0035] (d) flexor carpi radialis: 15 U to 60 U
[0036] (e) biceps brachii: 50 U to 200 U. Each of the five
indicated muscles has been injected at the same treatment session,
so that the patient receives from 90 U to 360 U of upper limb
flexor muscle BOTOX.RTM. by intramuscular injection at each
treatment session.
[0037] (7) to treat migraine, pericranial injected (injected
symmetrically into glabellar, frontalis and temporalis muscles)
injection of 25 U of BOTOX.RTM. has showed significant benefit as a
prophylactic treatment of migraine compared to vehicle as measured
by decreased measures of migraine frequency, maximal severity,
associated vomiting and acute medication use over the three month
period following the 25 U injection.
[0038] Additionally, intramuscular botulinum toxin has been used in
the treatment of tremor in patients with Parkinson's disease,
although it has been reported that results have not been
impressive. Marjama-Lyons, J., et al., Tremor-Predominant
Parkinson's Disease, Drugs & Aging 16(4);273-278:2000.
[0039] It is known that botulinum toxin type A can have an efficacy
for up to 12 months (European J. Neurology 6 (Supp 4):
S111-S1150:1999), and in some circumstances for as long as 27
months. The Laryngoscope 109:1344-1346:1999. However, the usual
duration of an intramuscular injection of Botox.RTM. is typically
about 3 to 4 months.
[0040] The success of botulinum toxin type A to treat a variety of
clinical conditions has led to interest in other botulinum toxin
serotypes. Additionally, pure botulinum toxin has been used in
humans. see e.g. Kohl A., et al., Comparison of the effect of
botulinum toxin A (Botox (R)) with the highly-purified neurotoxin
(NT 201) in the extensor digitorum brevis muscle test, Mov Disord
2000; 15(Suppl 3):165 Hence, a pharmaceutical composition can be
prepared using a pure botulinum toxin.
[0041] The botulinum toxin molecule (about 150 kDa), as well as the
botulinum toxin complexes (about 300-900 kDa), such as the toxin
type A complex are also extremely susceptible to denaturation due
to surface denaturation, heat, and alkaline conditions. Inactivated
toxin forms toxoid proteins which may be immunogenic. The resulting
antibodies can render a patient refractory to toxin injection.
[0042] As with enzymes generally, the biological activities of the
botulinum toxins (which are intracellular peptidases) are
dependant, at least in part, upon their three dimensional
conformation. Thus, botulinum toxin type A is detoxified by heat,
various chemicals surface stretching and surface, drying.
Additionally, it is known that dilution of the toxin complex
obtained by the known culturing, fermentation and purification to
the much, much lower toxin concentrations used for pharmaceutical
composition formulation results in rapid detoxification of the
toxin unless a suitable stabilizing agent is present. Dilution of
the toxin from milligram quantities to a solution containing
nanograms per milliliter presents significant difficulties because
of the rapid loss of specific toxicity upon such great dilution.
Since the toxin may be used months or years after the toxin
containing pharmaceutical composition is formulated, the toxin must
be stabilized with a stabilizing agent. To date, the only
successful stabilizing agent for this purpose has been the animal
derived proteins human serum albumin and gelatin. And as indicated,
the presence of animal derived proteins in the final formulation
presents potential problems in that certain stable viruses, prions,
or-other infectious or pathogenic compounds carried through from
donors can contaminate the toxin.
[0043] Furthermore, any one of the harsh pH, temperature and
concentration range conditions required to lyophilize (freeze-dry)
or vacuum dry a botulinum toxin containing pharmaceutical
composition into a toxin shipping and storage format (ready for use
or reconstitution by a physician) can detoxify the toxin. Thus,
animal derived or donor pool proteins such as gelatin and serum
albumin have been used with some success to stabilize botulinum
toxin.
[0044] A commercially available botulinum toxin containing
pharmaceutical composition is sold under the trademark BOTOX.RTM.
(available from Allergan, Inc., of Irvine, Calif.). BOTOX.RTM.
consists of a purified botulinum toxin type A-complex, human serum
albumin, and sodium chloride packaged in sterile, vacuum-dried
form. The botulinum toxin type A is made from a culture of the Hall
strain of Clostridium botulinum grown in a medium containing N-Z
amine and yeast extract. The botulinum toxin type A complex is
purified from the culture solution by a series of acid
precipitations to a crystalline-complex consisting of the active
high molecular weight toxin protein and an associated hemagglutinin
protein. The crystalline complex is re-dissolved in a solution
containing saline and albumin and sterile filtered (0.2 microns)
prior to vacuum-drying. BOTOX.RTM. can be reconstituted with
sterile, non-preserved saline prior to intramuscular injection.
Each vial of BOTOX.RTM. contains about 100 units (U) of Clostridium
botulinum toxin type A complex, 0.5 milligrams of human serum
albumin and 0.9 milligrams of sodium chloride in a sterile,
vacuum-dried form without a preservative.
[0045] To reconstitute vacuum-dried BOTOX.RTM. sterile normal
saline without a preservative (0.9% Sodium Chloride injection) is
used bydrawing up the proper amount of diluent in the appropriate
size syringe. Since BOTOX.RTM. is denatured by bubbling or similar
violent agitation, the diluent is gently injected into the vial.
For sterility reasons, BOTOX.RTM. should be administered within
four hours after reconstitution. During this time period,
reconstituted BOTOX.RTM. is stored in a refrigerator (2.degree. to
8.degree. C.). Reconstituted BOTOX.RTM. is clear, colorless and
free of particulate matter. The vacuum-dried product is stored in a
freezer at or below -5.degree. C.
[0046] Other commercially available botulinum toxin containing
pharmaceutical compositions include Dysport.RTM. (Clostridium
botulinum type A toxin hemagglutinin complex with human serum
albumin and lactose in the formulation, available from Ipsen
Limited, Berkshire, U.K. as a powder to be reconstituted with 0.9%
sodium chloride before use), and MyoBloc.TM. (an injectable
solution comprising botulinum toxin type B, human serum albumin,
sodium succinate, and sodium chloride at about pH 5.6, available
from Elan Corporation, Dublin, Ireland).
[0047] It has been reported that a suitable alternative to human
serum albumin as a botulinum toxin stabilizer may be another
protein or alternatively a low molecular weight (non-protein)
compound. Carpender et al., Interactions of Stabilizing Additives
with Proteins During Freeze-Thawing and Freeze-Drying,
International Symposium on Biological Product Freeze-Drying and
Formulation, Oct. 24-26, 1990; Karger (1992), 225-239.
[0048] Many substances commonly used as carriers and bulking agents
in pharmaceutical compositions have proven to be unsuitable as
albumin replacements in a Clostridial toxin containing
pharmaceutical composition. For example, the disaccharide
cellobiose has been found to be unsuitable as a botulinum toxin
stabilizer. Thus, it is known that the use of cellobiose as an
excipient in conjunction with albumin and sodium chloride results
in a much:lower level of toxicity (10% recovery) after
lyophilization of crystalline botulinum toxin type A with these
excipients, as compared to the toxicity after lyophilization with
only human serum albumin (>75% to >90% recovery). Goodnough
et al., Stabilization of Botulinum Toxin Type A During
Lyophilization, App & Envir. Micro. 58 (10) 3426-3428
(1992).
[0049] Furthermore, saccharides, including polysaccharides, are in
general poor candidates to serve as protein stabilizers. Thus, it
is known that a pharmaceutical composition containing a protein
active ingredient is inherently unstable if the protein formulation
comprises a saccharide (such as glucose or a polymer of glucose) or
carbohydrates because proteins and glucose are known to interact
together and to undergo the well-described Maillard reaction, due
to the reducing nature of glucose and-glucose polymers. Much work
has been dedicated to mostly unsuccessful attempts at preventing
this protein.-saccharide reaction by, for example, reduction of
moisture or use of non-reducing sugars. Significantly, the
degradative pathway of the Maillard reaction can result in a
therapeutic insufficiency of the protein active ingredient. A
pharmaceutical formulation comprising protein and a reducing
saccharide, carbohydrate or sugar, such as a glucose polymer, is
therefore inherently-unstable and cannot be stored for a long
period of time without significant loss of the active ingredient
protein's desired biological activity.
[0050] Notably, one of the reasons human serum albumin can function
effectively as a stabilizer of a protein active ingredient in a
pharmaceutical composition is because, albumin, being a protein,
does not undergo the Maillard reaction with the protein active
ingredient in a pharmaceutical composition. Hence, one would expect
to find and to look for a substitute for human serum albumin
amongst other proteins.
[0051] Finding an appropriate substitute for human serum albumin as
a stabilizer of the botulinum toxin present in a pharmaceutical
composition is difficult and problematic because human serum
albumin is believed to function in a pharmaceutical composition as
more than a mere bulking agent. Thus, albumin apparently can
interact with botulinum toxin so as to increase the potency of the
neurotoxin. For example, it is known that bovine serum albumin can
act as more than a mere stabilizing excipient for botulinum toxin
type A, since bovine serum albumin apparently also accelerates the
rate of catalysis of synthetic peptide substrates, which substrates
resemble the SNAP-25 intraneuronal substrate for botulinum toxin
type A Schmidt, et al., Endoproteinase Activity of Type A Botulinum
Neurotoxin Substrate Requirements and Activation by Serum Albumin,
J. of Protein Chemistry, 16 (1), 19-26 (1997). Thus, albumin may
have a potentiating effect, apparently by affecting rate kinetics,
upon the intracellular proteolytic action of a botulinum toxin upon
the toxin's substrate. This potentiating effect may be due to
albumin which has accompanied the botulinum toxin upon endocytosis
of the toxin into a target neuron or the potentiating effect may be
due to the pre-existing presence cytoplasmic albumin within the
neuron protein prior to endocytosis of the botulinum toxin.
[0052] The discovery of the presence of a kinetic rate stimulatory
effect by bovine serum albumin upon the proteolytic activity of
botulinum toxin type A renders the search for a suitable substitute
for albumin in a botulinum toxin containing pharmaceutical
formulation especially problematic. Thus, an albumin substitute
with desirable toxin stabilization characteristics may have an
unknown and possibly deleterious effect upon the rate of substrate
catalysis by the toxin, since at least with regard to bovine serum
albumin the two characteristics (toxin stabilization and toxin
substrate catalysis potentiation) are apparently inherent to the
same albumin excipient. This potentiating effect of albumin shows
that albumin does not act as a mere excipient in the formulation
and therefore renders the search for a suitable substitute for
albumin more difficult.
[0053] Additionally there are many unique characteristics of
botulinum toxin and its formulation into a suitable pharmaceutical
composition which constrain and hinder and render the search for a
replacement for the albumin used in current botulinum toxin
containing pharmaceutical formulations very problematic. Examples
of four of these unique characteristics follow.
[0054] First, botulinum toxin is a relatively large protein for
incorporation into a pharmaceutical formulation (the molecular
weight of the botulinum toxin type A complex is 900 kD) and is
therefore is inherently fragile and labile. The size of the toxin
complex-makes it much more friable and labile than smaller, less
complex proteins, thereby compounding the formulation and handling
difficulties if toxin stability is to be maintained. Hence, an
albumin replacement must be able to interact with the toxin in a
manner which does not denature, fragment or otherwise detoxify the
toxin molecule or cause disassociation of the non-toxin proteins
present in the toxin complex.
[0055] Second, as the most lethal known biological product,
exceptional safety, precision, and accuracy is called for at all
steps of the formulation of a botulinum toxin containing
pharmaceutical composition. Thus, a preferred potential albumin
replacer should not itself be toxic or difficult to handle so as to
not exacerbate the already extremely stringent botulinum toxin
containing pharmaceutical composition formulation requirements.
[0056] Third, since botulinum toxin was the first microbial toxin
to be approved (by the FDA in 1989) for injection for the treatment
of human disease, specific protocols had to be developed and
approved for the culturing, bulk production, formulation into a
pharmaceutical and use of botulinum toxin. Important considerations
are toxin purity and dose for injection. The production by
culturing and the purification must be carried out so that the
toxin is not exposed to any substance that might contaminate the
final product in even trace amounts and cause undue reactions in
the patient. These restrictions require culturing in simplified
medium without the use of animal meat products and purification by
procedures not involving synthetic solvents or resins. Preparation
of toxin using enzymes, various exchangers, such as those present
in chromatography columns and synthetic solvents can introduce
contaminants and are therefore excluded from preferred formulation
steps. Furthermore, botulinum toxin type A is readily denatured at
temperatures above 40 degrees C., loses toxicity when bubbles form
at the air/liquid interface, and denatures in the presence of
nitrogen or carbon dioxide.
[0057] Fourth, particular difficulties exist to stabilize botulinum
toxin type A, because type A consists of a toxin molecule of about
150 kD in noncovalent association with nontoxin proteins weighing
about 750 kD. The nontoxin proteins are believed to preserve or
help stabilize the secondary and tertiary structures upon which
toxicity is dependant. Procedures or protocols applicable to the
stabilization of nonproteins or to relatively smaller proteins are
not applicable to the problems inherent with stabilization of the
botulinum toxin complexes, such as the 900 kD botulinum toxin type
A complex. Thus while from pH 3.5 to 6.8 the type A toxin and non
toxin proteins are bound together noncovalently, under slightly
alkaline conditions (pH >7.1) the very labile toxin is released
from the toxin complex. As set forth previously, pure botulinum
toxin (i.e the 150 kD molecule) has been proposed as the active
ingredient in a pharmaceutical composition.
[0058] In light of the unique nature of botulinum toxin and the
requirements set forth above, the probability of finding a suitable
albumin replacement for the human serum albumin used in current
botulinum toxin containing pharmaceutical compositions must
realistically be seen to approach zero. Prior to the present
invention, only the animal derived proteins, human serum albumin
and gelatin, had been known to have utility as suitable stabilizers
of the botulinum toxin present in a pharmaceutical formulation.
Thus, albumin, by itself or with one or more additional substances
such as sodium phosphate or sodium citrate, is known to permit high
recovery of toxicity of botulinum toxin type A after
lyophilization. Unfortunately, as already set forth, human serum
albumin, as a pooled blood product, can, at least potentially,
carry infectious or disease causing elements when present in a
pharmaceutical composition. Indeed, any animal product or protein
such as human serum albumin or gelatin can also potentially contain
pyrogens or other substances that can cause adverse reactions upon
injection into a patient.
[0059] Chinese patent application CN 1215084A discusses an albumin
free botulinum toxin type A formulated with gelatin, an animal
derived protein. U.S. Pat. No. 6,087,327 also discloses a
composition of botulinum toxin types A and B formulated with
gelatin. These formulations therefore do not eliminate the risk of
transmitting an animal protein derived or accompanying infectious
element.
[0060] Acetylcholine
[0061] Typically only a single type of small molecule
neurotransmitter is released by each type of neuron in the
mammalian nervous system. The neurotransmitter acetylcholine is
secreted by neurons in many areas of the brain, but specifically by
the large pyramidal cells of the motor cortex, by several different
neurons in the basal ganglia, by the motor neurons that innervate
the skeletal muscles, by the preganglionic neurons of the autonomic
nervous system (both sympathetic and parasympathetic), by the
postganglionic neurons of the parasympathetic nervous system, and
by some of the postganglionic neurons of the sympathetic nervous
system. Essentially, only the postganglionic sympathetic nerve
fibers to the sweat glands, the piloerector muscles and a few blood
vessels are cholinergic as most of the postganglionic neurons of
the sympathetic nervous system secret the neurotransmitter
norepinephrine. In most instances acetylcholine has an excitatory
effect. However, acetylcholine is known to have inhibitory effects
at some of the peripheral parasympathetic nerve endings, such as
inhibition of heart rate by the vagal nerve.
[0062] The efferent signals of the autonomic nervous system are
transmitted to the body through either the sympathetic nervous
system or the parasympathetic nervous system. The preganglionic
neurons of the sympathetic nervous system extend from preganglionic
sympathetic neuron cell bodies located in the intermediolateral
horn of the spinal cord. The preganglionic sympathetic nerve
fibers, extending from the cell body, synapse with postganglionic
neurons located in either a paravertebral sympathetic ganglion or
in a prevertebral ganglion. Since, the preganglionic neurons of
both the sympathetic and parasympathetic nervous system are
cholinergic, application of acetylcholine to the ganglia will
excite both sympathetic and parasympathetic postganglionic
neurons.
[0063] Acetylcholine activates two types of receptors, muscarinic
and nicotinic receptors. The muscarinic receptors are found in all
effector cells stimulated by the postganglionic, neurons of the
parasympathetic nervous system as well as in those stimulated by
the postganglionic cholinergic neurons of the sympathetic nervous
system. The nicotinic receptors are found in the adrenal medulla,
as well as within the autonomic ganglia, that is on the cell
surface of the postganglionic neuron at the synapse between the
preganglionic and postganglionic neurons of both the sympathetic
and parasympathetic systems. Nicotinic receptors are also found in
many nonautonomic nerve endings, for example in the membranes of
skeletal muscle fibers at the neuromuscular junction.
[0064] Acetylcholine is released from cholinergic neurons when
small, clear, intracellular vesicles fuse with the presynaptic
neuronal cell membrane. A wide variety of non-neuronal secretory
cells, such as, adrenal medulla (as well as the PC12 cell line) and
pancreatic islet cells release catecholamines and parathyroid
hormone, respectively, from large dense-core vesicles. The PC12
cell line is a clone of rat pheochromocytoma cells extensively used
as a tissue culture model for studies of sympathoadrenal
development. Botulinum toxin inhibits the release of both types of
compounds from both types of cells in vitro, permeabilized (as by
electroporation) or by direct injection of the toxin into the
denervated cell. Botulinum toxin is also known to block release of
the neurotransmitter glutamate from cortical synaptosomes cell
cultures.
[0065] A neuromuscular junction is formed in skeletal muscle by the
proximity of axons to muscle cells. A signal transmitted through
the nervous system results in an action potential at the terminal
axon, with activation of ion channels and resulting release of the
neurotransmitter acetylcholine from intraneuronal synaptic
vesicles, for example at the motor endplate of the neuromuscular
junction. The acetylcholine crosses the extracellular space to bind
with acetylcholine receptor proteins on the surface of the muscle
end plate. Once sufficient binding has occurred, an action
potential of the muscle cell causes specific membrane ion channel
changes, resulting in muscle cell contraction. The acetylcholine is
then released from the muscle cells and metabolized by
cholinesterases in the extracellular space. The metabolites are
recycled back into the terminal axon for reprocessing into further
acetylcholine.
[0066] Hydroxyethyl Starch
[0067] A polysaccharide can be made up of hundreds or even
thousands of monosaccharide units held together by glycoside
(ether) linkages. Two important polysaccharides are cellulose and
starch. Cellulose is the chief structural material in plants,
giving plants their rigidity and form. Starch makes up the reserve
food supply of plants and is found mainly in various seeds and
tubers.
[0068] Starch occurs as granules whose size and shape are
characteristic of the plant from which the starch is obtained. In
general about 80% of starch is a water insoluble fraction called
amylopectin. Amylopectin is made up of chains of D-glucose (as
glucopyranose) units, each unit being joined by an alpha glycoside
linkage to C-4 of the next glucose unit. Like starch, cellulose is
also made up of chains of D-glucose units, where each unit is
joined by a glucoside linkage to the C-4 of the next unit. Unlike
starch though, the glycoside linkages in cellulose are beta
linkages. Treatment of cellulose with sulfuric acid and acetic
anhydride yields the disaccharide cellobiose. As previously set
forth, attempts to stabilize botulinum toxin using cellobiose have
been unsuccessful.
[0069] A particular starch derivative which can be obtained by
treating starch with pyridine and ethylene chlorohydrin, is
2-hydroxyethyl starch, also called hetastarch. U.S. Pat. No.
4,457,916 discloses a combination of a nonionic surfactant and
hydroxyethyl starch to stabilize aqueous solutions of tumor
necrosis factor (TNF).
[0070] Additionally, a 6% aqueous solution of 2-hydroxyethyl starch
(hetastarch) (available from Du Pont Pharma, Wilmington, Del. under
the trade name HESPAN.RTM., 6% hetastarch in 0.9% sodium chloride
injection) is. known. Albumin is known to act as a plasma volume
expander upon intravenous administration to a patient. HESPAN.RTM.
has also been administrated to patients to achieve a plasma volume
expansion effect and in that sense intravenous HESPAN.RTM. can be
considered a replacement for intravenous albumin.
[0071] Hetastarch is an artificial colloid derived from a waxy
starch composed almost entirely of amylopectin. Hetastarch can be
obtained by introducing hydroxyethyl ether groups onto glucose
units of the, starch, and the resultant material can then be
hydrolyzed to yield a product with a molecular weight suitable for
use as a plasma volume expander. Hetastarch is characterized by its
molar substitution and also by its molecular weight. The molar
substitution can be approximately 0.75, meaning that hetastarch is
etherified to the extent that for every 100 glucose units of
hetastarch there are, on average, approximately 75 hydroxyethyl
substituent groups. The average molecular weight of hetastarch is
approximately 670 kD with a range of 450 kD to 800 kD and with at
least 80% of the polymer units falling within the range of 20 kD to
2,500 kD. Hydroxyethyl groups are attached by ether linkages
primarily at C-2 of the glucose unit and to a lesser extent at C-3
and C-6. The polymer resembles glycogen, and the polymerized
D-glucose units are joined primarily by .alpha.-1,4 linkages with
occasional .alpha.-1,6 branching linkages. The degree of branching
is approximately 1:20, meaning that there is an average of
approximately one .alpha.-1,6 branch for every 20 glucose monomer
units. Hetastarch is comprised of more than. 90% amylopectin.
[0072] The plasma volume expansion produced by HESPAN.RTM. can
approximate that obtained with albumin. Hetastarch molecules below
50 kD molecular weight are rapidly eliminated by renal excretion
and a single dose of approximately 500 mL of HESPAN.RTM.
(approximately 30 g) results in elimination in the urine of
approximately 33% of the administered HESPAN.RTM. within about 24
hours. The hydroxyethyl group of hydroxyethyl starch is not cleaved
in vivo, but remains intact and attached to glucose units when
excreted. Significant quantities of glucose are not produced as
hydroxyethylation prevents complete metabolism of the smaller
hydroxyethyl starch polymers
[0073] Cellulose can likewise be converted to a hydroxyethyl
cellulose. The average molecular weight of 2-hydroxyethyl cellulose
(a 2-hydroxyethyl ether of cellulose) is about 90 kD.
Unfortunately, hydroxyethyl cellulose, unlike hydroxyethyl starch,
is highly reactive and therefore unsuited for use as a stabilizer
of a protein active ingredient in a pharmaceutical formulation.
[0074] Pharmaceutical Compositions for Veterinary Use
[0075] Non human animals (or "animals" in this section) can suffer
from maladies and injuries that are painful and difficult to treat.
For example, some canine breeds, such as German Shepherds, commonly
suffer from hip dysplasia, and may require corrective surgery, such
as hip replacement. Horses may suffer from gastrointestinal
disorders, such as colic, that may result in significant pain.
Similarly, race horses frequently suffer from fractured or broken
bones. Horses may also suffer flexor tendon and suspensory ligament
injury. Ponies are particularly susceptible to founder, a painful
crippling disorder specific to horses. Additionally, juvenile
birds, such as parrots can be afflicted with scoliosis
[0076] Additionally, non human animals may be subjected to painful
and irreversible procedures, such as denervation, to modify
involuntary natural behaviors, for example ear and tail twitching,
in show horses for example. Such drastic procedures are performed
for cosmetic reasons. No other humane remedy currently exists to
correct such undesirable traits. These procedures permanently
damage the animals.
[0077] Animals may also cause severe injury to themselves due to
what would be a mild condition in humans. Wounds are often
exacerbated by stall rubbing in horses resulting in insufficient
healing and chronic sores. Sores and skin irritation can result in
serious infection in this manner. Other maladies not seen in human
patients exist in animals. For example, flies and parasites cause
discomfort and act as vectors for disease. Dogs often require
hospitalization and or restraint due to biting and scratching
related to fleas and mange. Collars are often placed around the
animal's neck to prevent the animal from scratching ears affected
by mites or surgical procedures. These maladies, if mediated for a
time sufficient for the affected area to heal or the parasite to be
removed, can be avoided, relieving the animal of suffering and
symptoms.
[0078] A significant barrier in treating animals and promoting
their recovery from injury or surgery is due to an inability to
instruct the animal about proper rest and rehabilitation
procedures. The difficulty of immobilizing an animal may result in
re-injury, self-injury, and/or improper healing. Minor injuries
often become catastrophic due to the difficulty of immobilizing
animals during and after treatment. Many times the animal must be
destroyed. In addition, wild animals (e.g., non-domestic animals)
that pose a danger to others or themselves may need to be
immobilized to safely return the animal to its native environment.
Typically, these animals are tranquilized and moved, or are
killed.
[0079] Another problem when treating animals arises from the
difficulty in administering proper dosages. Animals do not readily
swallow oral dosage forms of medicine and often offer violent
resistance to injections. Frequent application of short-acting
drugs may therefore not be possible. Accordingly, as opposed to
humans, animals may require long-acting, single injection
pharmaceuticals to receive adequate benefit from the drug.
[0080] While pharmaceutical compositions containing human protein
may not present problems from a single administration, except in
certain individuals or species, repeated dosing may initiate immune
responses in animals, including anaphylactic shock. As discussed
above, current formulations of botulinum toxin include human serum
albumin (HSA) as a stabilizing excipient. These formulations may
present serious problems for veterinary use because the presence of
a human protein may induce immunogenic responses in other animal
species, limiting the efficacy, utility, and safety of the drug.
Formulations which do not contain HSA as an excipient; however,
should not produce these antibodies. The lack of suitable
formulations of botulinum toxin for use in treating non-human
animals has impeded the development of methods of using botulinum
toxin in veterinary medicine.
[0081] Indeed, the majority, if not all, of research regarding the
therapeutic aspects of botulinum toxin has focused on the use of
botulinum toxin for treating human diseases or ailments. As a
necessary precursor, botulinum toxin has experimentally been
administered to animals to examine its safety and efficacy in
animal models of human diseases. For example, botulinum toxin type
B has been administered to mice to treat thermal hyperalgesia
(Tsuda et al., (1999) "In, vivo pathway of thermal hyperalgesia by
intrathecal administration of .beta.-methylene ATP in mouse spinal
cord: Involvement of the glutamate-NMDA receptor system", Br. J.
Pharmacol., 127(2):449-456). In addition, botulinum toxin type A
has been:
[0082] administered to piglets to relieve lower esophageal
sphincter (LES) pressure (U.S. Pat. No. 5,437,291, entitled "Method
for treating gastrointestinal muscle disorders and other smooth
muscle dysfunction");
[0083] injected into gastric wall of rats to treat obesity (Gui et
al., (2000) "Botulinum toxin injected in the gastric wall reduces
body weight and food intake in rats", Aliment Pharmacol Ther.,
14(6):829-834);
[0084] used to assess the efficacy of the neurotoxin to produce
better scar formation from facial cosmetic surgery in non-human
primates (Gassner et al., (2000) Plast. Reconst. Surg.,
105(6):1948-1953);
[0085] administered to rats to examine its ability to reduce pain
(Aoki et al., (2000) "Methods for treating pain", U.S. Pat. No.
6,113,915;
[0086] administered to rats and dogs to alter vocal cord dynamics
for treating spasmodic dysphonia and vocal cord paralysis in humans
(Inagi et al., (1998) "Physiologic assessment of botulinum toxin
effects-in the rat larynx", Laryngoscope, 108(7):1048-1054; and
Cohen and Thompson (1987) "Use of botulinum toxin to lateralize
true vocal cords: a biochemical method to relieve bilateral
abductor vocal cord paralysis", Ann. Otol. Rhinol. Laryngol.,
96(5):534-41); and
[0087] administered to the obicularis oculi muscle of the guinea
pig to examine the efficacy of the toxin to treat eye lid spasms
(Hom et al., (1993) "Botulinum toxin paralysis of the orbicularis
oculi muscle. Types and time course of alterations in muscle
structure, physiology and lid kinematics", Exp. Brain Res.,
96(1):39-53).
[0088] In addition, a botulinum toxin has been administered to
rabbits to assess the immunogenicity of the toxin when conjugated
with human serum albumin (HSA).
[0089] Because the administration of botulinum toxin to animals has
only been examined experimentally as a model for treating humans
with botulinum toxin, researchers have not been concerned with
long-term effects of the neurotoxin on animals. In particular, the
art has not addressed the immunogenicity of the botulinum toxin
compositions in the non-human animals receiving the neurotoxin.
Thus, it would be beneficial to have a neurotoxin composition with
reduced immunogenicity for use in veterinary care, and convenient
and effective methods for immobilizing or treating non-human
animals.
[0090] What is needed therefore is a botulinum toxin containing
pharmaceutical composition which is free of animal derived proteins
such as a blood pooled or blood fraction derived serum albumin or
gelatin.
DRAWINGS
[0091] FIG. 1 is a graph (a chromatogram) which shows the molecular
weight distribution (higher molecular weight moieties are to the
left) of a commercially available human serum albumin (top graph A)
and of a commercially available recombinant albumin (bottom graph
B). The x axis represents elution time in minutes using size
exclusion HPLC (high performance liquid chromatography) in TSK-3000
buffer. The y axis represents the UV response at the detection
wavelength of 280 nm.
[0092] FIG. 2 is a graph (a chromatogram) which shows the molecular
weight distribution (higher molecular weight moieties are to the
left) of Formulation A (an HSA botulinum toxin formulation, see
Table 1) (top graph C) and of Formulation B (a rHSA botulinum toxin
formulation, see Table 1) (bottom graph D). The x and y axes are as
in FIG. 1.
[0093] FIG. 3 is a bar graph which shows the potency in mouse
LD.sub.50 units (the y axis) of six different botulinum toxin
formulations (A-F) (along the x axis) upon the making of the
formulations (i.e. at T.sub.0) and after six months storage at -5
degrees C. (i.e. at T.sub.6).
SUMMARY
[0094] The present invention meets this need and provides a
botulinum toxin pharmaceutical composition which is free of animal
derived proteins such as a blood pooled or blood fraction derived
human serum albumin or gelatin. One embodiment of the present
invention is a botulinum toxin pharmaceutical composition wherein
the primary stabilizer present in the formulation is a
recombinantly made albumin.
[0095] The present invention encompasses new pharmaceutical
compositions, embodiments of which can provide a superior
replacement (i.e. by use of a recombinant albumin, with or without
additional stabilizers) for the serum or native albumin present as
a primary stabilizer in a pharmaceutical composition. Thus, my
invention encompasses new, stabilized botulinum toxin
pharmaceutical compositions, which can have the additional and
desirable characteristics of enhanced potency and/or an enhanced
antimicrobial activity. The serum or native albumin replacement
compound used has the characteristic of low, and preferably
negligible, immunogenicity when injected into a patient.
Additionally, the preferred human serum albumin replacer has a
rapid rate of clearance from the body after injection of the
pharmaceutical composition.
[0096] The present invention also provides a pharmaceutical
composition which is specific to non human animals.
[0097] Definitions
[0098] As used herein, the words or terms set forth below have the
following definitions.
[0099] "About" means that the item, parameter or term so qualified
encompasses a range of plus or minus ten percent above and below
the value of the stated item, parameter or term.
[0100] "Administration", or "to administer" means the step of
giving (i.e. administering) a pharmaceutical composition to a
subject. The pharmaceutical compositions disclosed herein are
"locally administered". Systemic (i.e. intravenous or oral) routes
of administration are excluded from the scope of the present
invention, to the extent that a systemic administration would
result in systemic effects of a systemically administered active
ingredient. Systemic administration of a targeted active ingredient
which does not result in systemic effects is not excluded from the
scope of the present invention. Local administration includes, but
is not limited to, intramuscular (i.m.) administration, intradermal
administration, subcutaneous administration, intrathecal
administration, intraperitoneal (i.p.) administration, topical
contact, and implantation of a slow-release device such as
polymeric implant or miniosmotic pump.
[0101] "Amino acid" includes polyamino acids.
[0102] "Animal protein free" means the absence of blood derived,
blood pooled and other animal derived products or compounds.
"Animal" means a mammal (such as a human), bird, reptile, fish,
insect, spider or other animal species. "Animal" excludes
microorganisms, such as bacteria. Thus, an animal protein free
pharmaceutical composition can include a Clostridial neurotoxin.
For example, an animal protein free pharmaceutical composition
means a pharmaceutical composition which is either substantially
free or essentially free or entirely free of a serum derived
albumin, gelatin and other animal derived proteins, such as
immunoglobulins. An example of an animal protein free
pharmaceutical composition is a pharmaceutical composition which
comprises or which consists of a botulinum toxin (as the active
ingredient) and a recombinantly made albumin or other recombinantly
made stabilizer or excipient.
[0103] "Botulinum toxin" means a neurotoxin produced by Clostridium
botulinum , as well as a botulinum toxin (or the light chain or the
heavy chain thereof) made recombinantly by a non-Clostridial
species. The phrase "botulinum toxin", as used herein, encompasses
the botulinum toxin serotypes A, B, C, D, E, F and G. Botulinum
toxin, as used herein, also encompasses both a botulinum toxin
complex (i.e. the 300, 600 and 900 kDa complexes) as well as the
purified botulinum toxin (i.e. about 150 kDa). "Purified botulinum
toxin" is defined as a botulinum toxin that is isolated, or
substantially isolated, from other proteins, including proteins
that form a botulinum toxin complex. A purified botulinum toxin may
be greater than 95% pure, and preferably is greater than 99%
pure.
[0104] "Clostridial neurotoxin" means a neurotoxin produced from,
or native to, a Clostridial bacterium, such as Clostridium
botulinum, Clostridium butyricum or Clostridium beratti, as well as
a Clostridial neurotoxin made recombinantly by a non-Clostridial
species.
[0105] "Domesticated animal" means an animal that has adapted to
human habitats.
[0106] Domesticated animals, as defined herein, are tame animals.
Accordingly, animals that live with humans, such as pets, are
domesticated animals. Farm animals are also domesticated animals as
disclosed herein. Laboratory animals are not domesticated animals
in reference to the disclosure herein. Humans are not domesticated
animals.
[0107] "Enhanced antimicrobial activity" with regard to a botulinum
toxin containing pharmaceutical composition means that the
composition (i.e. a zinc containing botulinum toxin pharmaceutical
composition with either HSA or rHSA as the primary stabilizer) does
not support or supports to a lesser extent the growth of a
particular microorganism, as compared to a reference (i.e. lacking
zinc) botulinum toxin pharmaceutical composition.
[0108] "Enhanced potency" with regard to a botulinum toxin
containing pharmaceutical composition means that the composition
has a potency (as determined, for example, by the mouse LD.sub.50
assay) which is from at least 5% and up to 40%, or more, greater
than the potency of a reference botulinum toxin pharmaceutical
composition. A reference botulinum toxin pharmaceutical composition
can contain a botulinum toxin, sodium chloride, HSA And no
zinc.
[0109] "Entirely free (i.e. "consisting of" terminology) means that
within the detection range of the instrument or process being used,
the substance cannot be detected or its presence cannot be
confirmed.
[0110] "Essentially free" (or "consisting essentially of") means
that only trace amounts of the substance can be detected.
[0111] "Immobilizing" means a step that prevents a subject from
moving one or more body parts. If a sufficient number of body parts
are immobilized, the subject will accordingly be immobilized. Thus,
"immobilizing" encompasses the immobilization of a body part, such
as a limb, and/or the complete immobilization of a subject.
[0112] "Modified botulinum toxin" means a botulinum toxin that has
had at least one of its amino acids deleted, modified, or replaced,
as compared to a native botulinum toxin. Additionally, the modified
botulinum toxin can be a recombinantly produced neurotoxin, or a
derivative or fragment of a recombinantly made neurotoxin. A
modified botulinum toxin retains at least one biological activity
of the native botulinum toxin, such as, the ability to bind to a
botulinum toxin receptor, or the ability to inhibit
neurotransmitter release from a neuron. One example of a modified
botulinum toxin is a botulinum toxin that has a light chain from
one botulinum toxin serotype (such as serotype A), and a heavy
chain from a different botulinum toxin serotype (such as serotype
B). Another example of a modified botulinum toxin is a botulinum
toxin coupled to a neurotransmitter, such as substance P.
[0113] "Patient" means a human or non-human subject receiving
medical or veterinary care. Accordingly, as disclosed herein, the
compositions may be used in treating any animal, such as
mammals.
[0114] "Pharmaceutical composition" means a formulation in which an
active ingredient can be a neurotoxin, such as a Clostridial
neurotoxin. The word "formulation" means that there is at least one
additional ingredient in the pharmaceutical composition besides a
neurotoxin active ingredient. A pharmaceutical composition is
therefore a formulation which is suitable for diagnostic or
therapeutic administration (i.e. by intramuscular or subcutaneous
injection or by insertion of a depot or implant) to a subject, such
as a human patient. The pharmaceutical composition can be: in a
lyophilized or vacuum dried condition; a solution formed after
reconstitution of the lyophilized or vacuum dried pharmaceutical
composition with saline or water, or; as a solution which does not
require reconstitution. The neurotoxin active ingredient can be one
of the botulinum toxin serotypes A, B, C.sub.1, D, E, F or G or a
tetanus toxin, all of which can be made natively by Clostridial
bacteria. As stated, a pharmaceutical composition can be liquid or
solid, for example vacuum-dried. The constituent ingredients of a
pharmaceutical composition can be included in a single composition
(that is all the constituent ingredients, except for any required
reconstitution fluid, are present at the time of initial
compounding of the pharmaceutical composition) or as a
two-component system, for example a vacuum-dried composition
reconstituted with a diluent such as saline which diluent contains
an ingredient not present in the initial compounding of the
pharmaceutical composition. A two-component system provides the
benefit of allowing incorporation of ingredients which are not
sufficiently compatible for long-term shelf storage with the first
component of the two component system. For example, the
reconstitution vehicle or diluent may include a preservative which
provides sufficient protection against microbial growth for the use
period, for example one-week of refrigerated storage, but is not
present during the two-year freezer storage period during which
time it might degrade the toxin. Other ingredients, which may not
be compatible with a Clostridial toxin or other ingredients for
long periods of time, may be incorporated in this manner; that is,
added in a second vehicle (i.e. in the reconstitution fluid) at the
approximate time of use.
[0115] "Polysacchadde" means a polymer of more than two saccharide
molecule monomers, which monomers can be identical or
different.
[0116] "Protein stabilizer" (or "primary stabilizer") is a chemical
agent that assists to preserve or maintain the biological structure
(i.e. the three dimensional conformation) and/or biological
activity of a protein (such as a Clostridial neurotoxin, such as a
botulinum toxin). Stabilizers can be proteins or polysaccharides.
Examples of protein stabilizers include hydroxyethyl starch
(hetastarch), serum albumin, gelatin, collagen, as well as a
recombinant albumin, gelatin or collagen. As disclosed herein, the
primary stabilizer can be a synthetic agent that would not produce
an immunogenic response (or produces an attenuated immune response)
in a subject receiving a composition containing the primary
stabilizer. In other embodiments of the invention, the protein
stabilizers may be proteins from the same species of animal that is
being administered the protein. Additional stabilizers may also be
included in a pharmaceutical composition. These additional or
secondary stabilizers may be used alone or in combination with
primary stabilizers, such as proteins and polysaccharides.
Exemplary secondary stabilizers include, but are not limited to
non-oxidizing amino acid derivatives (such as a tryptophan
derivate, such as N-acetyl-tryptophan ("NAT")), caprylate (i.e.
sodium caprylate), a polysorbate (i.e. P80), amino acids, and
divalent metal cations such as zinc. A pharmaceutical composition
can also include preservative agents such as benzyl alcohol,
benzoic acid, phenol, parabens and sorbic acid. A "recombinant
stabilizer" is a "primary stabilizer" made by recombinant means,
such as for example, a recombinantly made albumin (such as a
recombinantly made human serum albumin), collagen, gelatin or a
cresol, such as an M-cresol.
[0117] "Stabilizing", "stabilizes", or "stabilization" mean that a
pharmaceutical active ingredient ("PAI") retains at least 20% and
up to 100% of its biological activity (which can be assessed as
potency or as toxicity by an in vivo LD.sub.50 or Eb.sub.50
measure) in the presence of a compound which is stabilizing,
stabilizes or which provides stabilization to the PAI. For example,
upon (1) preparation of serial dilutions from a bulk or stock
solution, or (2) upon reconstitution with saline or water of a
lyophilized, or vacuum dried botulinum toxin containing
pharmaceutical composition which has been stored at or below about
-2 degrees C. for between six months and four years, or (3) for an
aqueous solution botulinum toxin containing pharmaceutical
composition which has been stored at between about 2 degrees and
about 8 degrees C. for from six months to four years, the botulinum
toxin present in the reconstituted or aqueous solution
pharmaceutical composition has (in the presence of a compound which
is stabilizing, stabilizes or which provides stabilization to the
PAI) greater than about 20% and up to about 100% of the potency or
toxicity that the biologically active botulinum toxin had prior to
being incorporated into the pharmaceutical composition.
[0118] "Substantially free" means present at a level of less than
one percent by weight of the pharmaceutical composition.
[0119] "Therapeutic formulation" means a formulation can be used to
treat and thereby alleviate a disorder or a disease, such as a
disorder or a disease characterized by hyperactivity (i.e.
spasticity) of a peripheral muscle.
[0120] A pharmaceutical composition within the scope of my
invention can comprise a Clostridial toxin, such as a botulinum
toxin, and a recombinant stabilizer. A pharmaceutical composition
within the scope of my invention can also consist essentially of a
botulinum toxin, and a recombinant stabilizer. Additionally,
pharmaceutical composition within the scope of my invention can
consist of a botulinum toxin, and a recombinant stabilizer.
[0121] The botulinum toxin can be present as a botulinum toxin
complex (i.e. as an approximately 300 to about 900 kiloDalton
complex depending upon the particular botulinum toxin serotype) or
the botulinum toxin can be is present as a pure or purified
botulinum toxin (i.e. as the botulinum toxin molecule of about 150
kiloDaltons). Additionally, the recombinant stabilizer can be a
recombinant albumin, a recombinant collagen, a recombinant gelatin
or other recombinant primary stabilizer. The pharmaceutical
composition can also comprise a secondary stabilizer, such as a
metal (i.e. zinc) or NAT.
[0122] Significantly, a pharmaceutical composition within the scope
of my invention can have an enhanced potency or stability. By
enhanced potency it is meant that the potency of a first botulinum
toxin pharmaceutical composition is greater than the potency of a
second botulinum toxin pharmaceutical composition. For example a
first botulinum toxin pharmaceutical composition can comprise a
recombinant primary stabilizer (such as a r-HSA) and a second
botulinum toxin pharmaceutical composition can comprise a
non-recombinant primary stabilizer (such as HSA). Alternately, a
first botulinum toxin pharmaceutical composition can comprise one
or more secondary stabilizers (such as zinc and/or NAT) whereas a
second botulinum toxin pharmaceutical composition lacks one or more
of the secondary stabilizers present in the first pharmaceutical
composition. Potency and relative potencies can be determined by a
method used to determine a biological activity of a botulinum
toxin, such as a mouse LD.sub.50 assay. Generally, greater potency
means that a lesser amount (i.e. fewer units) of a botulinum toxin
pharmaceutical composition is required to paralyze a muscle.
Preferably, a first botulinum toxin pharmaceutical composition has
at least a 5% greater potency (and as much as a 40% greater
potency) than does a second botulinum toxin pharmaceutical
composition.
[0123] Furthermore, a pharmaceutical composition within the scope
of my invention can have an enhanced anti-microbial activity. By
enhanced anti-microbial activity it is meant that the ability of a
first botulinum toxin pharmaceutical composition with a particular
component to inhibit the growth in a liquid solution of a
particular microorganism is greater than the ability of a liquid
solution of a second botulinum toxin pharmaceutical composition
without the particular component present in the first botulinum
toxin pharmaceutical composition to inhibit the growth of the same
microorganism under the same conditions.
[0124] A preferred embodiment of my invention comprises a botulinum
toxin (such as botulinum toxin type A) and a recombinant albumin.
An alternate preferred embodiment of my invention comprises a
botulinum toxin, NAT, and zinc.
[0125] Another preferred embodiment of my invention is a
pharmaceutical composition which can comprise (or which can consist
essentially of or which can consist of) a botulinum toxin, a
primary stabilizer, and a secondary stabilizer. The, primary
stabilizer can be a recombinant stabilizer (such as r-HSA) and the
secondary stabilizer can be a metal, such as zinc. Other suitable
secondary stabilizers can include caprylate (octanoate) and
NAT.
[0126] A pharmaceutical composition within the scope of the present
invention can also include a neurotoxin, and a polysaccharide. The
polysaccharide stabilizes the neurotoxin. The pharmaceutical
compositions disclosed herein can have a pH of between about 5 and
7.3 when reconstituted or upon injection. The average molecular
weight of a disaccharide unit of the polysaccharide is preferably
between about 345 D and about 2,000 D. In a more preferred
embodiment, the average molecular weight of a disaccharide unit of
the polysaccharide is between about 350 kD and about 1,000 kD and
in a most preferred embodiment between about 375 D and about 700 D.
Additionally, the polysaccharide can comprise at least about 70%
amylopectin. Furthermore, the weight average molecular weight of
the polysaccharide itself is between about 20 kD and about 2,500
kD.
[0127] Preferably, substantially all of the disaccharide units of
the polysaccharide comprise ether linked glucopyranose molecules.
An average of about 4 to about 10 of the hydroxyl groups present on
each 10 of the glucopyranoses present in the polysaccharide are
substituted, through an ether linkage, with a compound of the
formula (CH.sub.2).sub.n--OH, where n can be an integer from 1 to
10. More preferably, n is an integer between 1 and 3.
[0128] In a particularly preferred embodiment, an average of about
6 to about 9 of the hydroxyl groups present on each 10 of the
glucopyranoses present in the polysaccharide are substituted,
through an ether linkage, with a compound of the formula
(CH.sub.2).sub.n--OH, where n can be an integer from 1 to 10. And
in a most preferred embodiment, an average of about 7 to about 8 of
the hydroxyl groups present on each 10 of the glucopyranoses
present in the polysaccharide are substituted, through an ether
linkage, with a compound of the formula (CH.sub.2).sub.n--OH, where
n can be an integer from 1 to 10.
[0129] A detailed embodiment of the present invention can be a
pharmaceutical composition suitable for injection into a human
patient, which includes a botulinum toxin, and a polysaccharide.
The polysaccharide can comprise a plurality of linked glucopyranose
units, each glucopyranose unit having: a plurality of hydroxyl
groups, wherein an average of about 6 to about 9 of the hydroxyl
groups present on each 10 of the glucopyranoses present in the
polysaccharide are substituted, through an ether linkage, with a
compound of the formula (CH.sub.2).sub.n--OH, where n can be an
integer from 1 to 4. The polysaccharide can be an ethyl ether
substituted polysaccharide.
[0130] The pharmaceutical composition is suitable for
administration to a human patent to achieve a therapeutic effect,
and the neurotoxin can be one of the botulinum toxin serotypes A,
B, C.sub.1, D, E , F and G. In a preferred embodiment of the
present invention, the pharmaceutical composition comprises a
botulinum toxin, and a hydroxyethyl starch.
[0131] Another embodiment of the present invention can encompass a
pharmaceutical composition which includes a botulinum toxin, a
polysaccharide, and an amino acid or a polyamino acid.
[0132] Whether the pharmaceutical composition comprises, beside the
neurotoxin active ingredient, only a polysaccharide stabilizer,
only an amino acid stabilizer or both polysaccharide and amino acid
stabilizers, the pharmaceutical composition retains its potency
substantially unchanged for six month, one year, two year, three
year and/or four year periods when stored at a temperature between
about -1.degree. C. and about -15.degree. C. Additionally, the
indicated pharmaceutical compositions can have a potency or %
recovery of between about 20% and about 100% upon reconstitution.
Alternately or in addition, the pharmaceutical composition can have
a potency of between about 10 U/mg and about 30 U/mg upon
reconstitution, such as a potency of about 20 U/mg upon
reconstitution. Significantly, the pharmaceutical composition is
devoid of any albumin. Thus, the pharmaceutical composition can be
substantially free of any non-toxin complex proteins. Notably, the
amino acid can be present in an amount of between about 0.5 mg and
about 1.5 mg of amino acid per 100 units of botulinum toxin.
[0133] The polysaccharide can be a starch such as a hydroxyethyl
starch, which, when the pharmaceutical composition comprises about
100 units of the botulinum toxin, there can be between about 500
.mu.g and about 700 .mu.g of the hydroxyethyl starch present.
Preferably, the botulinum toxin is botulinum toxin type A, and the
amino acid, when present, is selected from the group consisting of
lysine, glycine, histidine and arginine.
[0134] A further detailed embodiment of the present invention can
be a stable, high potency, non-pyrogenic, vacuum dried botulinum
toxin type A pharmaceutical composition, comprising a botulinum
toxin type A complex, a polysaccharide, and, an amino acid or a
polyamino acid. The pharmaceutical composition can be albumin free,
have a 1 year shelf life at -5 C. with about 90% potency
immediately upon reconstitution with saline or water and about 80%
potency 72 hours after reconstitution and storage at 2 C.
Additionally, the pharmaceutical composition can have a specific
toxicity of at least about 10.sup.7 U/mg upon reconstitution.
[0135] My invention also encompasses a botulinum toxin formulation
which comprises a botulinum toxin hydroxyethyl starch (HES) glycine
and providine.
[0136] The present invention also encompasses a lyophilized or
vacuum dried pharmaceutical composition consisting essentially of a
high molecular weight polysaccharide and a botulinum toxin, wherein
the botulinum toxin is stabilized by the high molecular weight
polysaccharide. The high molecule weight polysaccharide can be
selected from the group consisting of hydroxymethyl starch,
hydroxyethyl starch, hydroxypropyl starch, hydroxybutyl starch, and
hydroxypentyl starch and The botulinum toxin can be selected from
the group consisting of botulinum toxin types A, B, C.sub.1, D, E,
F and G.
[0137] The polysaccharide can be present in the pharmaceutical
composition in an amount of between about 1.times.10.sup.-9 moles
of the polysaccharide per unit of a botulinum toxin to about
2.times.10.sup.-12 moles of the polysaccharide per unit of the
botulinum toxin.
[0138] The present invention also includes (a) a method for making
a pharmaceutical composition, comprising the step of preparing a
mixture of a botulinum toxin and a polysaccharide comprised of
covalently linked repeating monomers, wherein the average monomer
molecular weight is between about 350 D and about 1,000 D, and (b)
a method for stabilizing a clostridial neurotoxin against
denaturation or aggregation, the method comprising the step of
contacting a clostridial neurotoxin with a stabilizing composition
comprising a polysaccharide. The contacting step in this later
method can comprise the step of adding to an aqueous solution or to
a lyophilized or vacuum dried powder containing a clostridial
neurotoxin an effective amount of the polysaccharide.
[0139] A further aspect of the present invention is a
pharmaceutical composition, comprising a botulinum toxin, and a
recombinantly made albumin. This composition preferably also
includes an acetyltryptophanate and salts and derivatives
thereof.
[0140] An additional embodiment of the present invention is a
device for injecting a pharmaceutical composition comprising a dual
chamber prefilled syringe, one chamber of which syringe contains a
botulinum toxin and the second chamber of which syringe contains a
diluent or buffer.
[0141] A further embodiment of the present invention is a method
for using a pharmaceutical composition, the method comprising the
step of local administration of the pharmaceutical composition to a
patient to achieve a therapeutic effect, wherein the pharmaceutical
composition comprises a botulinum toxin, a polysaccharide and an
amino acid.
[0142] Significantly, my invention also includes a pharmaceutical
composition, comprising a botulinum toxin, and an amino acid. My
invention also includes a stable pharmaceutical composition,
consisting essentially of a botulinum toxin, and an amino acid.
These pharmaceutical compositions can be albumin free,
polysaccharide free, has a 1 year shelf life at -5 C. with at least
about 90% potency upon reconstitution with saline or water and
about 80% potency 72 hours after reconstitution and storage at 2
C.
[0143] In one aspect of the invention, a method for immobilizing a
mammal comprises the step of administering a composition, which
comprises at least one botulinum toxin serotype and a
polysaccharide that stabilizes the botulinum toxin and is
nonimmunogenic to the mammal. In one embodiment, the foregoing
method may be practiced by administering a composition comprising a
hetastarch. In another embodiment of the invention, a method for
immobilizing a mammal, comprises the step of administering a
composition to the mammal, wherein the composition comprises (i) at
least one botulinum toxin serotype, and (ii) a polysaccharide,
which comprises a plurality of linked glucopyranose units that each
have a plurality of hydroxyl groups present on each of the
glucopyranoses present in the polysaccharide are substituted,
through an ether linkage, with a compound of the formula
(CH.sub.2).sub.n--OH, where n can be an integer from 1 to 4.
[0144] In another embodiment of the invention, a method for
immobilizing a mammal comprises the step of administering a
composition to the mammal, wherein the composition comprises a
botulinum toxin, and a hydroxyethyl starch, thereby immobilizing
the mammal.
[0145] In practicing the foregoing methods, the mammal may be a
non-human animal.
[0146] In another embodiment of the invention, a method for
treating a domesticated animal comprises the step of administering
botulinum toxin to the animal. The botulinum toxin may be
administered in a pharmaceutical composition. Preferably, the
botulinum toxin is administered to the animal in a composition that
has a low immunogenicity thereby reducing, and preferably
preventing, the development of immunity by the animal to the
botulinum toxin. The botulinum toxin may be any one of the seven
serotypes of botulinum toxin, or a recombinantly synthesized
botulinum toxin. The botulinum toxin may be administered as an
acute treatment, or it may be administered chronically.
[0147] In another embodiment of the invention, a method for
treating a domesticated animal comprises the step of administering
at least one botulinum toxin serotype and a polysaccharide that
stabilizes the botulinum toxin, to the domesticated animal. In one
embodiment, the polysaccharide is a hydroxyethyl starch.
[0148] In certain embodiments of the invention, the administration
of the neurotoxin composition may reduce pain experienced by the
animal. In additional embodiments, the animal receiving the
neurotoxin may be injured, and the foregoing method promotes the
animal's recovery from the injury. One example of an injury that
benefits from the invention is a leg injury, such as a broken bone.
In practicing the foregoing methods, the compositions disclosed
herein may be administered to the injured body part.
[0149] The foregoing methods may also be useful in helping a mammal
recover from surgery. One example of a surgical procedure is hip
dysplasia surgery. Another example is surgery for a broken
bone.
[0150] The foregoing methods may be practiced utilizing a
composition that comprises a botulinum toxin type A. In other
embodiments of the invention, the foregoing methods may be
practiced with a composition that comprises botulinum toxin type B.
In further embodiments of the invention, the methods may be
practiced with a composition that comprises a plurality of
botulinum toxin serotypes, such as botulinum toxin serotypes
selected from the group consisting of botulinum toxin serotypes A,
B, C.sub.1, D, E, F and G. In certain embodiments of the invention,
purified botulinum toxins may be used. In other embodiments,
modified botulinum toxins may be used. The compositions used in the
foregoing methods may also include one or more amino acids in
addition-to the botulinum toxin and the polysaccharide.
[0151] In yet additional embodiments of the invention, the
compositions used in the foregoing methods may be administered
intramuscularly to the patient. In other embodiments, the
compositions may be administered subcutaneously and/or
intrathecally.
DESCRIPTION
[0152] The present invention is based upon the discovery that a
stable botulinum toxin with enhanced potency and enhanced
antimicrobial activity as well as being free of animal derived
proteins, such as a blood pooled or blood fraction derived human
serum albumin or gelatin, can be made with a recombinant
albumin.
[0153] The present invention also encompasses a stable Clostridial
toxin containing pharmaceutical composition formulated free of any
animal derived protein or donor pool albumin by incorporating a
polysaccharide, an amino acid and/or a recombinant albumin into the
pharmaceutical composition. In particular, the present invention
encompasses a stable botulinum toxin containing pharmaceutical
composition suitable for administration to a patient for
therapeutic effects made by replacing the donor pool albumin
present in known botulinum toxin containing pharmaceutical
compositions with a high molecular weight polysaccharide derived
from starch and/or with certain reactive amino acids.
Recombinant Albumin Botulinum Toxin Pharmaceutical Compositions and
Zinc Containing Botulinum Toxin Pharmaceutical Compositions
[0154] An embodiment of my invention is a botulinum toxin active
ingredient pharmaceutical composition wherein, instead of human
serum albumin, the primary protein stabilizer is a recombinantly
made albumin. I have surprising found that a botulinum toxin
pharmaceutical composition comprising a recombinant albumin has a
greater potency than does a botulinum toxin pharmaceutical
composition comprising the same amount (on a weight for weight
basis) of a human serum albumin.
[0155] A further embodiment of my invention is a pharmaceutical
composition comprising a botulinum toxin as the active ingredient,
an albumin (either a serum albumin or a recombinantly made albumin)
primary protein stabilizer and a metal cation, such as zinc, as a
secondary stabilizer.
[0156] Human serum albumin (plasma derived) is available
commercially from various sources, including, for example, from
Bayer Corporation, pharmaceutical division, Elkhart, Ill., under
the trade name Plasbumin.RTM.. Plasbumin.RTM. is known to contain
albumin obtained from pooled human venous plasma as well as sodium
caprylate (a fatty acid, also known as octanoate) and
acetyltryptophan ("NAT"). See e.g. the Bayer Plasbumin.RTM.-20
product insert (directions for use) supplied with the product and
as published at http://actsysmedical.com/PDF/plasbumin20.pdf. The
caprylate and acetyltryptophan in commercially available human
serum albumin are apparently added by FDA requirement to stabilize
the albumin during pasteurization at 60 degrees C. for 10 hours
prior to commercial sale. See e.g. Peters, T., Jr., All About
Albumin Biochemistry, Genetics and Medical Applications, Academic
Press (1996), pages 295 and 298. Recombinant human albumin is
available from various sources, including for example, from Bipha
Corporation of Chitose, Hokkaido, Japan, Welfide Corporation of
Osaka, Japan, and from Delta Biotechnology, Nottingham, U.K., as a
yeast fermentation product, under the trade name
Recombumin.RTM..
[0157] It is known to express recombinant human serum albumin
(rHSA) in the yeast species Pichia pastoris. See e.g. Kobayashi K.,
et al., The development of recombinant human serum albumin, Ther
Apher November 1998; 2(4):257-62, and; Ohtani W., et al.,
Physicochemical and immunochemical properties of recombinant human
serum albumin from Pichia pastoris, Anal Biochem Feburary 1, 1998;
256(1):56-62. See also U.S. Pat. No. 6,034,221 and European patents
330 451 and 361 991. A clear advantage of a rHSA is that it is free
of blood derived pathogens.
[0158] As set forth herein, I have discovered that a botulinum
toxin containing pharmaceutical formulation can be made with a
recombinant albumin ("rA") as a primary protein stabilizer. The rA
can be a recbmbinantly made human serum albumin ("rHSA"). As set
forth above, it is known that a rHSA can be expressed by
genetically altered yeast host cells. Unexpectedly, I discovered
that a pharmaceutical composition comprising a botulinum toxin (as
the active ingredient) and a recombinant albumin (as the primary
protein stabilizer) has a greater potency than does a
pharmaceutical composition comprising a botulinum toxin (as the
active ingredient) and a human serum albumin (as the primary
protein stabilizer). It was surprising to discover that a rA, such
as a rHSA, can be used to stabilize a botulinum toxin, particularly
in light of the known kinetic rate effect of HSA upon botulinum
toxin. While it is generally believed that the amino acid sequences
of HSA and rHSA are identical, there are a number of distinctions
between HSA and rHSA which, without wishing to be bound by theory,
may be responsible for the observed surprising and unexpected
greater potency of a botulinum toxin pharmaceutical composition
formulated with an rHSA, as compared to a botulinum toxin
pharmaceutical composition formulated with a HSA.
[0159] For example:
[0160] (1) While eukaryotic, yeast lack many intracellular
processes found in mammals. Thus HSA is made in non-glycosylated
form and (unlike rHSA) undergoes extracellular, non-enzymatic
addition of glucose. Hence, the carbohydrate moieties
(substituents) HSA and rHSA differ. The presence of, and differing,
substituents can cause cbnformational, and hence activity
differences.
[0161] (2) As a blood derived product, HSA contains significant
amounts of fatty acid impurities, such as palmitic acid and stearic
acid, which fatty acids are present not at all, or in much lower
amounts, with rHSA. The fatty acids which accompany the HSA from
blood as an impurity can mask albumin binding sites, and this
binding site masking is not present with rHSA, since little or no
fatty acid impurity is present with a r-HSA.
[0162] (3) HSA is prepared by centrifugation (to accomplish blood
fractionation) or other separation processes, while no such
processing/separation steps are required for rHSA. Hence, the 3D
albumin molecular confirmation can differ between HSA and rHSA.
[0163] (4) the molecular weight distribution of HSA differs
significantly from the molecular weight distribution of rHSA, as
determined by an experiment I carried out to determine the
molecular weight distributions of HSA v rHSA. Thus, FIG. 1 shows
that commercially available HSA "A" (the upper graph A in FIG. 1)
has a significant amount of aggregate present (labeled as "a" in
FIG. 1. Aggregate is an aggregation of trimer and higher molecular
weight albumin) whereas a commercially available rHSA "B" (the
lower graph B in FIG. 1) has no detectable aggregate albumin. In
FIG. 1 "b" represents detected dimer, "c" represents detected
monomer and "d" represents detected NAT. As shown by FIG. 1 no
albumin aggregate ("a") (nor any NAT) was present in the rHSA
examined.
[0164] Additionally, I determined by experiment (see FIG. 2) that
only about 90% of the human serum albumin present in a final
botulinum toxin pharmaceutical composition (i.e Formulation A) was
present as albumin monomers (see graph C in FIG. 2), at the time of
preparation of the pharmaceutical composition. But I also
determined by experiment that about 95% (i.e. more than 90%) of the
recombinant serum albumin present in a botulinum toxin
pharmaceutical composition was present as albumin monomers, at the
time of preparation of this pharmaceutical composition (see graph D
in FIG. 2). These results therefore show that not only in
commercial rHSA preparations (i.e. in the raw material of this
primary stabilizer), but also in the final rHSA botulinum toxin
pharmaceutical composition there is significantly less albumin
aggregate present, as compared to both the corresponding a HSA raw
material and the final HSA botulinum toxin pharmaceutical
composition.
[0165] (5) The isoelectric point (pl) for HSA is 5.2, but is 5.1
for rHSA.
[0166] (6) HSA can contain a number of impurities: low molecular
weight impurities can include citrate (as a residue of the sodium
citrate anticoagulant used in plasma collection), fatty acids and
lipids (as an associated blood fraction component) and various
metals present due to the filters (i.e diatomaceous earth) and
blood fraction processing and separation technologies used. High
molecular substances can be present with the HSA because commercial
HSA preparations can legally contain as much as 4% of non-albumin
globulins, such as orosomucoid. Thus, FDA requirements are that
commercially available HSA need be only at least 96% HSA, so up to
4% of non-HSA impurities can be present with HSA. Additionally,
polymeric forms of albumin (dimers, trimers) are known to be
present in commercially available lots of HSA. See e.g. Peters, T.
Jr., Chapter 7, Practical Aspects: Albumin in the Laboratory, of
All About Albumin, Biochemistry, genetics, and medical
applications, pages 298-305, Academic Press (1996).
[0167] These six differences can be expected to result in
significant differences in, inter alia, ligand binding,
conformational stability and molecular charge between HSA and rHSA,
thereby resulting in significant differences between an HSA
botulinum toxin pharmaceutical composition as compared to a rHSA
botulinum toxin pharmaceutical composition, the later being as
aspect of my invention. Thus, even though the amino acid sequences
of HSA and rHSA may be identical I discovered that a botulinum
toxin pharmaceutical composition formulated with an rHSA can have
an enhanced potency as compared to a botulinum toxin pharmaceutical
composition formulated with HSA.
[0168] Thus, as set forth an aspect of my invention encompasses
replacement of the blood derived serum albumin in a pharmaceutical
composition with a recombinant albumin (rA), such as a recombinant
human serum albumin (rHSA). As explained below, preferably, the
recombinant serum albumin can be present in the botulinum toxin
containing pharmaceutical formulation with acetyltryptophanate
("NAT"), as well as with P80 and caprylate.
[0169] Commercially available human serum albumin is heated at
60.degree. C. for ten hours as a requirement to eliminate
potentially infectious agents derived from the human blood pool. In
order to prevent serious denaturation during this process two
stabilizers are added: sodium acetyltryptophanate ("NAT") and
sodium caprylate. With a rHSA (or other recombinant albumin) there
is no need to add these ingredients because no disease risk exists
and hence no heating step is required.
[0170] I have discovered that addition of sodium
acetyltryptophanate (NAT) to rHSA enhances the thermal stability
beyond that obtained by use of sodium caprylate alone, even when
the concentration of sodium caprylate is almost doubled (from 20 mM
for a HSA to 35.2 mM for a rHSA). Without wishing to be bound by
theory, I believe that may be due to the caprylate binding to only
one site on the albumin molecule whereas sodium acetyltryptophanate
binds to two sites on the albumin molecule. Binding this second
site appears to enhance the resistance the albumin molecule to
thermal perturbation. I can further postulate that the addition of
sodium acetyltryptophanate may in some way enhance the stability of
botulinum toxin formulations, possibly by maintaining a
thermodynamically favorable conformation in the toxin molecule,
binding the toxin, or by preventing denaturation of the human serum
albumin itself. Therefore a preferred embodiment of my invention is
a pharmaceutical composition which comprises a botulinum toxin (as
the active ingredient), a rA (such as a rHSA) as a primary protein
stabilizer and a secondary stabilizer such as: N-Acetyl-tryptophan
(sodium tryptophanate or NAT); sodium caprylate; another fatty
acids; and divalent cations such as zinc (for example as zinc
chloride). A more preferred botulinum toxin pharmaceutical
composition within the scope of my invention comprises a botulinum
toxin, a rHSA and NAT. A very preferred botulinum toxin
pharmaceutical composition within the scope of my invention
comprises a botulinum toxin, a rHSA, NAT, a caprylate, zinc and P80
(i.e. Formulation E) because of its high potency. A most preferred
formulation is Formulation B because this formulation has a higher
potency than the HSA formulation (i.e. Formulation A) (see FIG. 3),
and is more similar in composition to the already. FDA approved
Formulation A (BOTOX) than is the even more potent Formulation
E.
[0171] An embodiment of my invention can consist essentially of a
botulinum toxin, a rHSA and NAT, so that other excipients which do
not materially effect the basic characteristics of the composition,
such as sodium caprylate, Zinc and. P80, can also be present as
further stabilizers of the botulinum toxin active ingredient, and
certain trace process buffers and sodium chloride can also be
present. A most preferred embodiment of my invention can consist of
a botulinum toxin, a recombinant albumin (human or other species)
and a tryptophanate, such as NAT, because I have discovered that
such a composition provides a stabilized botulinum toxin. A most
preferred botulinum toxin pharmaceutical composition within the
'scope of my invention can consist of a botulinum toxin, a rHSA,
NAT, a caprylate and P80.
[0172] Importantly, as set forth below, I have made the surprising
and unexpected discovery that a stable pharmaceutical composition
consisting essentially of a botulinum toxin, an albumin, and zinc
(with or without NAT) exhibits significant and dramatic
anti-microbial activity against a wide variety of microbial
species. This is an unexpected discovery because most preservatives
have been shown to be incompatible with protein drugs, including
with botulinum toxin.
[0173] A most preferred pharmaceutical composition within the scope
of my invention comprises, consists essentially of or consists of a
botulinum toxin (i.e. 100 units, about 4.8-5 ng), sodium chloride
(about 900 .mu.g), a rHSA (about 500 .mu.g), sodium caprylate
(about 13 .mu.g), NAT (about 10 .mu.g), Zinc chloride (about 4
.mu.g) and P80 (about 0.04 .mu.g)
[0174] As stated, sodium caprylate and/or sodium
acetyltryptophanate ((NAT) can be added to commercially available
HSA to protect the HSA from denaturation while the HSA (required by
FDA rules) is heated to 60 degrees C. for 10-11 hours before the
HSA can be sold.
[0175] My invention also encompasses addition of a zinc ion source
to a botulinum toxin containing pharmaceutical formulation. It has
been determined that zinc does not provide cryoprotection to a
botulinum toxin during the freeze drying step in the preparation of
a freeze dried botulinum toxin pharmaceutical composition. Prior to
my invention it was not known that zinc can have a stabilizing
function on a botulinum toxin. It can be postulated that metals,
such as divalent metal cations, may be able to enhance the
stability of a freeze-dried formulation due to various
cryo-properties including the lattice structures of formed ices.
Extraneous metals such as copper and iron species lend themselves
to radical oxidations and are generally to be avoided. It is known
that botulinum toxin type A toxin is dependent upon bound zinc for
its intracellular enzymatic activity. Many of the art known
excipients or reaction products of these excipients, including
albumin, can chelate metals. This could lead to formation of
unstable ices and/or inactivated toxin. By supplying ample zinc in
the formulation the presence of desirable divalent cations is
assured, the likelihood of zinc loss by the toxin is reduced, and
stability enhanced. This can be accomplished by the addition of
ZnSO.sub.4 or ZnCl.sub.2 to a botulinum toxin pharmaceutical
composition.
Polysaccharide Containing Pharmaceutical Composition
[0176] In another embodiment of my invention, I have surprisingly
found that a suitable replacement for albumin can be a compound
which is neither another protein, nor a low molecular weight,
non-protein compound. Thus, I have discovered that particular high
molecular weight polysaccharides can function as neurotoxin
stabilizers in a pharmaceutical composition. As set forth below, an
amino acid can also, or in the alternative, be added to the
pharmaceutical composition to increase the stability and useful
storage life of the pharmaceutical composition.
[0177] The polysaccharide used in the present invention can impart
stability to a neurotoxin active ingredient, such as a botulinum
toxin, present in the pharmaceutical composition by: (1) reducing
adhesion (commonly referred to as "stickiness") of the botulinum
toxin to surfaces, such as the surfaces of laboratory glassware,
vessels, the vial in which the pharmaceutical composition is
reconstituted and the inside surface of the syringe used to inject
the pharmaceutical composition. Adhesion of the botulinum toxin to
surfaces can lead to loss of botulinum toxin and to denaturation of
retained botulinum toxin, both of which reduce the toxicity of the
botulinum toxin present in the pharmaceutical composition. (2)
reducing the denaturation of the botulinum toxin and/or
dissociation of the botulinum toxin from other non-toxin proteins
present in the botulinum toxin complex, which denaturation and/or
dissociation activities can occur because of the low dilution of
the botulinum toxin present in the pharmaceutical composition (i.e.
prior to lyophilization or vacuum drying) and in the reconstituted
pharmaceutical composition. (3) reducing loss of botulinum toxin
(i.e. due to denaturation or dissociation from non-toxin proteins
in the complex) during the considerable pH and concentration
changes which take place during preparation, processing and
reconstitution of the pharmaceutical composition.
[0178] The three types of botulinum toxin stabilizations provided
by the polysaccharide conserve and preserve the botulinum toxin
with it native toxicity prior to injection of the pharmaceutical
composition.
[0179] In addition, I have discovered that the protein stabilizers
disclosed herein reduce the immunogenicity of the pharmaceutical
compositions, and thereby are useful in treating conditions that
might benefit from neurotoxin treatments in human and non-human
subjects. Surprisingly, I have discovered a composition that
permits administration of a neurotoxin, such as botulinum toxin, to
both human and non-human subjects without resulting in a
significant immune response. As discussed above, the presence of
HSA in the currently available products of botulinum toxin may
preclude the ability for veterinarians to administer botulinum
toxin as a treatment for animals.
[0180] In certain embodiments of the invention, the pharmaceutical
compositions of the invention may comprise a plurality of botulinum
toxin serotypes. In other words, the composition may include two or
more different botulinum toxin serotypes. For example, a
composition may include botulinum toxin serotypes A and B. In
another embodiment, a composition may include botulinum toxin
serotypes A and E. Using a combination of botulinum toxin serotypes
will permit caregivers to customize the composition to achieve a
desired effect based on the condition being treated. In an
additional embodiment of the invention, the composition may
comprise a modified botulinum toxin. The modified botulinum toxin
will preferably inhibit the release of neurotransmitter from a
neuron, but may have a greater or lower potency than the native
botulinum toxin, or may have a greater or lower biological effect
than the native botulinum toxin. Because the compositions of the
invention may be used for relatively long-term treatment of
animals, the compositions may be provided in a relatively pure
form. In one embodiment, the compositions are of a pharmaceutical
grade. In certain embodiments, the clostridial neurotoxin has a
greater than 95% purity. In additional embodiments, the clostridial
neurotoxin has a purity greater than 99%.
[0181] A preferred polysaccharide for use in the present
composition comprises a plurality of glucose monomers (mol wt 180)
with one or more substituents on a majority of the glucose
monomers, so that the preferred polysaccharide has a molecular
weight range of between about 20 kD and about 800 kD. Surprisingly,
such-a polysaccharide can stabilize a neurotoxin component present
in a pharmaceutical composition. The present invention excludes
from its scope disaccharide oligosaccharides with a weight average
molecular weight of less than about 20 kD. The present invention
also excludes from its scope cyclic polymers such as the
cyclodextrins. The latter two classes of compounds are excluded
from the scope of the present invention because the desired
stabilization characteristics of the preferred polysaccharide while
requiring a relatively high molecular compound (i.e. molecular
weight in excess of 20 kD) do not require and indeed can make no
use of the small lipophilic cavity characteristic of the
cyclodextrins, because the cyclodextrin lipophilic cavity is much
smaller in size than the size of the neurotoxins stabilized by the
preferred polysaccharides of the present invention. Additionally,
the cyclodextrins are low molecular weight compounds comprising
only about 6 to 8 glucose monomers.
[0182] The present invention also encompasses a method for
stabilizing pharmaceutical compositions which contain a clostridial
toxin with a polysaccharide. The stabilizing effect is achieved by
bringing a clostridial toxin in contact with the polysaccharide.
Examples of suitable polysaccharides within the scope of my
invention include certain starch and starch derivatives. As noted,
the polysaccharide exhibits a stabilizing effect on the clostridial
toxin. Furthermore, the effect of the polysaccharide to stabilize a
clostridial toxin can be enhanced by the addition of an amino
acid.
[0183] Unexpectedly, I have discovered that 2-hydroxyethyl starch
demonstrates a unique ability to stabilize the botulinum toxin
present in a botulinum toxin containing pharmaceutical composition,
thereby providing a pharmaceutical composition which is devoid of
the potential for harboring a transmissible disease derived from
human blood or blood fraction donor pools or animal derived
proteins like gelatin.
[0184] Thus, I have discovered that the particular high molecular
weight polysaccharide, hydroxyethyl starch, can stabilize the toxin
during formulation, drying, storage and reconstitution. Preferably,
to further stabilize the protein active ingredient, an amino acid
is also included in the polysaccharide containing formulation.
[0185] The polysaccharide in the pharmaceutical composition is
preferably admixed with the clostridial neurotoxin in an amount of
about 1 .mu.g of polysaccharide per unit of botulinum toxin to
about 10 .mu.g of polysaccharide per unit of botulinum toxin. More
preferably the polysaccharide in the pharmaceutical composition is
admixed with the clostridial neurotoxin in an amount of about 4
.mu.g of polysaccharide per unit of botulinum toxin to about 8
.mu.g of polysaccharide per unit of botulinum toxin. In a most
preferred embodiment, where the polysaccharide is a hydroxyethyl
starch, the hydroxyethyl starch in the pharmaceutical composition
is preferably admixed with a botulinum toxin type A complex in an
amount of about 5 .mu.g of hydroxyethyl starch per unit of
botulinum toxin to about 7 .mu.g of hydroxyethyl starch per unit of
botulinum toxin. Most preferably, the hydroxyethyl starch in the
pharmaceutical composition is admixed with a botulinum toxin type A
complex in an amount of about 6 .mu.g of hydroxyethyl starch per
unit of botulinum toxin. Since BOTOX.RTM. contains about 100 units
of botulinum toxin type A complex per vial and the average
molecular weight of hydroxyethyl starch is generally regarded as
being between about 20 kD and about 2,500 kD, the most preferred
concentration of hydroxyethyl starch is between about
1.times.10.sup.-9 moles per unit of botulinum toxin (M/U) to about
2.times.10.sup.-12 moles per unit of botulinum toxin. In another
preferred embodiment, for a 100 U botulinum toxin type A complex
pharmaceutical composition, about 600 .mu.g of the hydroxyethyl
starch and about 1 mg of an amino acid, such as lysine, glycine,
histidine or arginine is included in the formulation. Thus, my
invention encompasses use of both a polysaccharide and an amino
acid, or a polyamino acid to stabilize the neurotoxin active
ingredient in the pharmaceutical composition.
[0186] Additionally, my invention also encompasses use of a
suitable amino acid in a sufficient amount to stabilize the protein
active ingredient in a pharmaceutical composition, either in the
presence of or to the exclusion of any polysaccharide being present
in the formulation. Thus, I have surprisingly discovered that the
inclusion of certain amino acids into a neurotoxin containing,
pharmaceutical composition formulation can extend the useful shelf
life of such a pharmaceutical composition. Thus, my invention
encompasses a neurotoxin containing pharmaceutical composition
which includes an amino acid and the use of such a pharmaceutical
composition. Without wishing to be bound by theory, I can postulate
that since a neurotoxin, such as a botulinum toxin, is susceptible
to oxidation, due to the presence of disulfide linkages in the
toxin complex, the inclusion of an oxidizable amino acid may act to
reduce the probability that oxidizers, such as peroxides and free
radicals, will react with the neurotoxin. Thus, the likelihood that
the oxidizable neurotoxin disulfide linkage will be oxidized by an
oxidizer, such as peroxides and free radicals, can be reduced upon
inclusion of an amino acid which can act as an oxidative sink, that
is as a scavenger for oxidizing compounds. A suitable amino acid is
an amino acid which is subject to oxidation. Examples of preferred
amino acids are methionine, cysteine, tryptophan and tyrosine. A
particularly preferred amino acid is methionine.
[0187] A preferred embodiment of my invention can also include the
use of two or more amino acids either alone or in combination with
a polysaccharide to stabilize the protein active ingredient in a
pharmaceutical composition. Thus, for a 100 U botulinum toxin type
A containing pharmaceutical composition, about 0.5 mg of lysine and
about 0.5 mg of glycine can be used, either with or without between
about 500 .mu.g and about 700 .mu.g of hetastarch.
[0188] Thus, as set forth above, my invention encompasses a protein
containing, pharmaceutical composition which includes a
polysaccharide. The polysaccharide acts to stabilize the protein
active ingredient in the pharmaceutical composition. Additionally,
my invention also includes a protein containing, pharmaceutical
composition which includes a polysaccharide and an amino acid.
Surprisingly, I have discovered that the inclusion of certain amino
acids into a neurotoxin containing, pharmaceutical composition
formulation which includes a carbohydrate can extend the useful
shelf life of such a pharmaceutical composition. Thus, my invention
encompasses a neurotoxin containing pharmaceutical composition
which includes both a polysaccharide and an amino acid and the use
of such a pharmaceutical composition. Furthermore, my invention
also encompasses use of an amino acid without any polysaccharide
being present in the protein active ingredient pharmaceutical
composition.
[0189] It is known that protein containing pharmaceutical
compositions which also contain sugars, polysaccharides and/or
carbohydrates (referred to hereafter as `reactive compounds") are
inherently unstable due to the fact that a protein and one of the
three indicated reactive compounds can undergo the well-described
Maillard reaction. Extensive, largely fruitless, research has been
carried out to try and reduce the incidence or prevalence of this
(for example) protein-polysaccharide Maillard reaction, by
reduction of moisture or by the use of non-reducing sugars in the
formulation. My discovery is based upon the observation that
inclusion of a high concentration of a highly reactive amino acid
encourages the Maillard reaction to take place between the
stabilizing polysaccharide and the added amino acid. By providing
an abundant amine source for the carbohydrate to react with, the
probability of the protein drug (i.e. botulinum toxin active
ingredient) becoming involved in the Maillard is reduced, thereby
reducing this degradation pathway of the protein active ingredient
and in this manner thereby stabilizing the protein active
ingredient in the pharmaceutical composition.
[0190] Preferably, any compound containing a primary or secondary
amine can be used for this purpose. Most preferred are amino acids,
such as lysine, glycine, arginine. Polyamino acids, such as
polylysine are also'suitable. Cationic amino acids such as lysine
may undergo ionic attraction, binding acidic proteins (e.g.,
botulinum toxins) and shield the active protein from contact with
sugars. Polylysine, in addition to being larger and therefore more
likely to act as a shield, provides the additional advantage of
being antibacterial.
[0191] Another aspect of my invention is to pre-react the sugar and
amino acid components to exhaust Maillard reaction potential before
adding the active protein component (botulinum toxin) to the sugar
and amino acid formulation ingredients, thereby substantially
limiting the active protein's exposure to Maillard reactions.
[0192] Thus, my invention encompasses a pharmaceutical composition
containing and the use of an amino acids and polyamino acids as
Maillard reaction inhibitors in protein (i.e. botulinum toxin) drug
formulations which contain starches, sugars and/or
polysaccharides.
[0193] The invention embodies formulations of active proteins
(e.g., botulinum toxin) in combination with a stabilizing starch,
sugar, or polysaccharide or combination of these, and an amino acid
such as lysine.
[0194] Significantly, I have discovered that hydroxypthyl starch
does not undergo or undergoes a much attenuated rate or level of
Maillard reactions with a protein, such as a botulinum toxin, when
hydroxyethyl starch is compared to other polysaccharides or
carbohydrates. Additionally, I have discovered that inclusion of an
amino acid enhances the preservation effect of hydroxyethyl starch,
possibly by acting as a competitive inhibitor, that is by competing
with the toxin for Maillard reaction reactive sugars. For this
purpose, amino acids such as lysine, glycine, arginine and
histidine are preferred amino acids. Polyamino acids, such as
polylysine, which exhibit the desired competitive inhibition
behavior can also be used. Notably, the specified amino and poly
amino acids can also exhibit antimicrobial properties, providing
therefore the added benefit of reducing bacterial contamination in
the pharmaceutical composition.
[0195] Reducing sugars, such as glucose and glucose polymers,
undergo Maillard reaction with proteins. Even sugar alcohols like
mannitol can react, albeit sometimes through contaminants or
degradation products. Therefore a polysaccharide can stabilize the
toxin for a period-of time only to chemically react later, thereby
causing reduced storage stability. It-is obvious that the choice of
polysaccharide is critical. I have discovered that the rate of
hydroxyethyl starch participation in the Maillard reaction is very
low. Additionally, I have found that hydroxyethyl cellulose,
although structurally very similar to hydroxyethyl starch, is
unsuitable to use as a stabilizer, since I have found that
hydroxyethyl cellulose can rapidly react in a model system with
lysine. This not only means that hydroxyethyl starch has an obvious
advantage over other sugar (i.e. polysaccharide) stabilizers, but
that even excipients similar to hydroxyethyl starch, such as
hydroxyethyl cellulose, can be unsuitable to use as stabilizers of
a protein active ingredient in a pharmaceutical formulation.
[0196] As noted, hydroxyethyl starch, can participate to at least
some extent, in Maillard reactions. Thus, and as set forth above, a
polysaccharide alone may not be sufficient to provide optimal
stabilization of the toxin. Thus, I discovered the advantages of
inclusion of an amino acid to act as a competitive inhibitor.
Without wishing to be bound by theory, the hypothesis is that by
providing another amine source, in high concentrations compared to
the toxin, the probability of the Maillard reaction occurring with
the toxin is reduced, thereby stabilizing the toxin. Any amino acid
can be used however lysine being highly reactive and is a preferred
amino acid.
[0197] Although recombinant serum albumin is preferred over
animal-derived serum albumin, it is a further aspect of my
invention to provide a composition that may comprise a serum
albumin obtained from the species of animal intended to be treated.
For example, if a horse were to receive an injection of a
clostridial neurotoxin, such as botulinum toxin, it may be
desirable to utilize a composition comprising the neurotoxin and an
equine serum albumin as a stabilizer. Similarly, if a cow were to
receive an injection of a clostridial neurotoxin, the composition
containing the neurotoxin may include bovine serum albumin as a
stabilizer. This reasoning will similarly apply to other animal
species, including primate serum albumin for non-human primates,
porcine serum albumin for pigs, canine serum albumin for dogs,
feline serum albumin for cats, and murine serum albumin for
rodents. Other species-specific serum albumins are provided in the
compositions of the invention.
[0198] One composition of the invention may comprise botulinum
toxin type A, and serum albumin from horses, dogs, cats, rabbits,
pigs or rodents.
[0199] Another composition of the invention may comprise botulinum
toxin type B, C.sub.1, D, E, F, or G; and serum albumin from
non-human primates, cows, horses, pigs, dogs, cats or rodents.
[0200] As persons skilled in the art will readily appreciate,
although the serum derived albumins may have some of the
shortcoming discussed herein, they may still find some use in
veterinary care.
[0201] My invention also encompasses addition of a preservative,
either in the diluent or formulation itself, to allow extended
storage. A preferred preservative is preserved saline containing
benzyl alcohol.
[0202] A liquid formulation can be advantageous. A single-step
presentation (e.g., pre-filled syringe) or a product configuration
that the user perceives as a single-step presentation (e.g.,
dual-chambered syringe) would provide convenience by eliminating
the reconstitution step. Freeze-drying is a complicated, expensive
and difficult process. Liquid formulations are often easier and
cheaper to produce. On the other hand liquid formulations are
dynamic systems and therefore more susceptible to excipient
interaction, fast reactions, bacterial growth, and oxidation than
freeze-dried formulations. A compatible preservative might be
needed. Anti-oxidants such as methionine might also be useful as
scavengers especially if surfactants are used to reduce adsorption
as many of these compounds contain or produce peroxides. Any of the
stabilizing excipients which can be used in a freeze-dried
formulation (e.g., hydroxyethyl starch or an amino acid such,
lysine) might be adapted to use in a liquid formulation to assist
in reducing adsorption and stabilize the toxin. Suspensions similar
to those developed for insulin are also good candidates.
Additionally, stabilizing botulinum toxin in a liquid vehicle might
require a low pH vehicle as the toxin is reported to be labile
above pH 7. This acidity could produce burning and stinging upon
injection. A binary syringe could be employed. Inclusion of a
co-dispensed buffer, sufficient to raise the pH to physiologic
levels, would alleviate injection discomfort of a low pH while
maintaining the toxin at a low pH during storage. Another
dual-chambered syringe option would include diluent and lyophilized
material segregated in separate chamber, only mixing upon use. This
option provides the advantages of a liquid formulation without the
additional resources and time.
[0203] Thus, the botulinum toxin can be prepared at low pH to be
co-dispensed with a buffer which raises the pH to at or near
physiological pH at the time of administration. The two chamber or
binary syringe can have in the first chamber (next to the plunger)
a liquid formulation of a botulinum toxin with a pH between 3 to 6
(i.e. at pH 4.0). The second chamber (next to the needle tip) can
contain a suitable buffer, such as phosphate buffered saline at a
higher pH (i.e. pH 7.0). Alternately, the first chamber can contain
a saline diluent and the second chamber can contain a freeze dried
or lyophilized neurotoxin formulation. The two chambers can be
joined in such a way and the buffering components selected in such
a way that the solutions mix at or near the needle, thereby
delivering the final solution at a physiological pH. Suitable two
chamber syringes to use as pre-filled syringes for the purposes set
forth herein can be obtained from Vetter Pharma-Fertigung of
Yardley, Pa.
[0204] There are distinct advantages to formulating botulinum toxin
at a low pH. The toxin has a low isoelectric point (pl) and
formulating proteins near their pi is a known way to stabilize a
protein. Additionally, the toxin is used at a very low
concentration making surface adsorption a problem. Use of a low pH
solution can suppress ionization of toxin sites likely to interact
with surfaces. The syringe and plunger materials are materials
which reduce surface adsorption by the toxin. Suitable such
materials are polypropylene.
[0205] As discussed herein, the neurotoxin may be prepared and
purified using techniques well-known in the art. The purified toxin
may subsequently be diluted in a stabilizer such as a
polysaccharide (e.g., hetastarch), or a recombinant serum albumin,
or a serum albumin of the species of animal receiving the
neurotoxin. It is preferred that the stabilizer prevents or reduces
denaturation of the toxin, and produces no, or minimal, immunogenic
responses in the animal that will receive the toxin. Aliquots of
the diluted toxin are then lyophilized using conventional
procedures.
[0206] The lyophilized neurotoxin may be reconstituted before
administering the neurotoxin to a subject by adding water, saline,
or any buffer solution to the lyophilized neurotoxin. In certain
embodiments, sodium free buffers may be preferred to help reduce
denaturation of the neurotoxin.
[0207] The pharmaceutical compositions-of the invention can be
administered using conventional modes of administration. In
preferred embodiments of the invention, the compositions are
administered intramuscularly or subcutaneously to the subject. In
other embodiments, the compositions of the invention may be
administered intrathecally. In addition, the compositions of the
invention may be administered with one or more analgesic or
anesthetic agents.
[0208] The most effective mode of administration and dosage regimen
for the compositions of this invention depends upon the type,
severity, and course of the condition being treated, the animal's
health and response to treatment, and the judgment of the treating
doctor. Accordingly, the methods and dosages of the compositions
should be tailored to the individual subject.
[0209] By way of example, and not by way of limitation, it may be
preferred to administer the composition of the invention
intramuscularly to reduce muscle spasms associated with a specific
condition. Spasms in veterinary animals can be caused by congenital
defects (Hickford et al., J Small Anim Pract 1998 39(6):281-5), hip
dysplasia (Bowen, Am J Vet Res 1974 35(5):661-8), inflammation
(Anderson and Harvey, J Vet Dent 1993 10(1):6-8) multiple
sclerosis, stroke, tumors, traumas, or neurologic degenerative
diseases. Administering the compositions disclosed herein to
animals may be particularly effective in treating specific
conditions such as "teary eyes" or "tail flick" in animals.
Injecting botulinum toxin periodically (e.g., every three to six
months) in the same areas may allow for long term, indefinite
relief of spastic symptoms in these animals without the unwanted
development of resistance to the toxin.
[0210] Similarly, the compositions of the invention may be
administered intramuscularly to immobilize an injured animal.
Injuries that result in fractures and tendon rupture require-the
limb associated with the site of injury to be completely
immobilized so as to prevent reinjury. Although the site is placed
in a cast, often the animals will reinjure themselves with ongoing
activity. The only way to completely immobilize the animal is
general anesthesia, which cannot be employed for long term uses. In
addition, immobilization of the injured body part with a cast, for
example, may cause bone malformation and with improper functional
recovery (Hawthorne et al., J Am Anim Hosp Assoc 1999
35(2):135-146).
[0211] Intramuscular injection of the compositions of the invention
can result in selective and reversible immobilization of the
animal, or body parts thereof. For example, the compositions of the
invention may be administered locally to one or more muscle groups
of an injured body part. In other cases, it may be necessary to
perform whole body immobilization of the musculature involved in
whole body movements (limb muscles and abdominal muscles) without
impinging the respiratory system or muscles involved in food
intake. In such a scenario, the animal will not be able to
willfully move any parts of the body involved in ambulatory
movements, so physical restraints may not be necessary. Other
functions required to maintain the overall health of the animal
would preferably be still intact, so therefore a normal functioning
animal is kept at a "temporary paralytic" state. Furthermore,
depending on the type of neurotoxin in the composition administered
to the animal, the rate of recovery may be controlled. For example,
a composition containing botulinum toxin type E may be administered
if the caregiver decides that a relatively shorter time of
paralysis is needed to promote recovery. In addition, because the
effects of the neurotoxin wear off gradually, the activity of the
immobilized body parts can be regained at a rate which is most
desirable to achieve proper healing and recovery.
[0212] The compositions of the invention may also be injected into
smooth muscles (as compared to striated muscles) to treat colonic,
bladder, esophageal, or gastrointestinal dysfunction, including,
but not limited to achalasia, anal fissure, hyperactive sphincter
of oddi. The administration of the compositions may reduce or
prevent unfavorable systemic consequences from treatment with drugs
that do not specifically act on the organ of interest.
[0213] Compositions containing botulinum toxin may be administered
intramuscularly, intrathecally, or subcutaneously to relieve pain
experienced by the animal. These treatments are also restricted to
the site of injection and have minimal side effects compared to
current systemic approaches of treating these pain syndromes with
pain relieving drugs.
[0214] Pain may be difficult to determine in an animal; however,
animals may exhibit one or more behaviors indicative of the animal
experiencing pain. For example, the animal may cease its normal
activities, or it may favor a potentially injured limb. The animal
may stop eating, may whine, may have an increased respiration rate,
or heart rate, may have an abnormal temperature, or may appear
restless. In addition, animals experience intestinal discomfort,
such as colic, and may experience one or more of the following
symptoms in addition to the symptoms identified above, paw the
ground, may sweat, may be restless, may appear bloated, and
experience muscle tremors.
[0215] Relief from pain by practicing the methods of the invention
may be determined by observing the reduction in the number of
symptoms that the animal is exhibiting. One or more of the symptoms
may be reduced.
[0216] Injection of botulinum toxin to multiple muscles, such as
leg muscles, may be effective to cause a potent, prolonged, yet
reversible immobilization of wild, non-domesticated animals. This
procedure can be used for medical evaluation of the patient,
various local or minor medical or dental procedures, or for
transport. In practicing these methods, it may be desirable to also
inject either before, or at the same time, a tranquilizer to
provide immediate effects of immobilization.
[0217] As indicated above, dosages of the neurotoxin, such as
botulinum toxin, in the compositions may vary. In one embodiment,
the compositions contain a therapeutically effective amount of
neurotoxin, for example, between about 1 U and about 500 U of
botulinum toxin type A. Preferably the amounts are between about 10
U and about 300 U. More preferably the amount is between about 20 U
and 250 U, such about 50 U to 200 U, or 70 U. Alternatively,
botulinum toxin, such as botulinum toxin type A, can be
administered in amounts between about 10.sup.-3 U/kg and about 60
U/kg to alleviate pain experienced by a mammal. Preferably, the
botulinum toxin used is administered in an amount of between about
10.sup.-2 U/kg and about 50 U/kg. More preferably, the botulinum
toxin is administered in an amount of between about 10.sup.-1 U/kg
and about 40 U/kg. Most preferably, the botulinum toxin is
administered in an amount of between about 1 U/kg and about 30
U/kg. In a particularly preferred embodiment of the present
disclosed methods, the botulinum toxin is administered in an amount
of between about 1 U/kg and about 20 U/kg.
[0218] Compositions containing other serotypes of botulinum toxin
may contain different dosages of the botulinum toxin. For example,
botulinum toxin type B may be provided in a composition at a
greater dose than a composition containing botulinum toxin type A.
In one embodiment of the invention, botulinum toxin type B may be
administered in an amount between about 1 U/kg and 150 U/kg.
Botulinum toxin type B may also be administered in amounts of up to
20,000 U (mouse units, as described above). In another embodiment
of the invention, botulinum toxin types E or F may be administered
at concentrations between about 0.1 U/kg and 150 U/kg. In addition,
in compositions containing more than one type of botulinum toxin,
each type of botulinum toxin can be provided in a relatively
smaller dose than the dose typically used for a single botulinum
toxin serotype. The combination of botulinum toxin serotypes may
then provide a suitable degree and duration of paralysis without an
increase in diffusion of the neurotoxins (e.g. see U.S. Pat. No.
6,087,327).
EXAMPLES
[0219] The following examples set forth specific embodiments of the
present invention and are not intended to limit the scope of the
invention.
Example 1
Human Serum Albumin Botulinum Toxin Pharmaceutical Composition
(Formulation A)
[0220] A botulinum toxin type A complex can be obtained from a
culture of the Hall strain of Clostridium botulinum grown in a
medium containing N-Z amine and yeast extract. The botulinum toxin
type A complex is purified from the culture solution by a series of
acid precipitations to a crystalline complex consisting of the
active high molecular weight toxin protein and an associated
hemagglutinin protein. The crystalline complex is then re-dissolved
in, a solution containing saline and albumin and sterile filtered
(0.2 microns) prior to vacuum-drying. The vacuum dried composition
can be reconstituted with sterile, non-preserved saline prior to
injection. Each vial of vacuum dried composition can contain about
100 units (U) of Clostridium botulinum toxin type A complex, 0.5
milligrams of human serum albumin and 0.9 milligrams of sodium
chloride in a sterile, vacuum-dried form without a preservative
(Formulation A).
Example 2
Recombinant Human Serum Albumin Botulinum Toxin Pharmaceutical
Composition
(Formulation B)
[0221] A botulinum toxin type A complex was obtained as set forth
in Example 1 and the same pharmaceutical composition made, except
that instead of HSA, an rHSA was used in the formulation.
Example 3
Potency Differences Between Human Serum Albumin Botulinum Toxin
Pharmaceutical Compositions and Recombinant Human Serum Albumin
Botulinum Toxin Pharmaceutical Compositions
[0222] Upon lyophilization and after less than one week of storage
at -5 degrees C. (i.e. at T.sub.0) the vacuum dried pharmaceutical
compositions of Examples 1 and 2 (i.e. Formulations A and B) were
reconstituted with sterile normal saline without a preservative
(0.9% sodium chloride injection) and their respective potencies
determined by the known mouse LD50 assay. Other samples of the
lyophilized botulinum toxin type A complex Formulations A and B (as
well as samples of the Formulations C-F described below) were
stored at -5 degrees C. for six months and then reconstituted with
the sterile normal saline without a preservative (0.9% sodium
chloride injection) and their respective potencies were again
determined (i.e. at T.sub.6) using the mouse LD50 assay.
[0223] Table 1 sets forth the constituents of the six different
botulinum toxin pharmaceutical compositions made. Formulations B,
C, E and F in Table 1 contain a rHSA. Formulations A and D in Table
1 contain an HSA. As shown by FIG. 3, it was found that:
[0224] (a) the potency of Formulation A was 85 at T.sub.0 and 72 at
T.sub.6.
[0225] (b) the potency of Formulation B was 96 at T.sub.0 and 95 at
T.sub.6. This experiment therefore showed that Formulation B was
13% more potent at T.sub.0 and 32% more potent at T.sub.6 than was
Formulation A. Thus, it was found that surprisingly the rHSA
formulation (B) was more potent than was the HSA formulation
(A).
[0226] (c) the potency of a Formulation B to which 10 micrograms of
NAT were added per 100 units of toxin (to thereby make a
Formulation C) was 100 at T.sub.0 and 97 at T.sub.6. This
experiment therefore showed that Formulation C was 18% more potent
at T.sub.0 and 35% more potent at T.sub.6 than was Formulation A.
Thus, it was found that surprisingly, the addition of NAT to the
rHSA formulation (B) further increased the potency of Formulation B
as compared to the HSA formulation, Formulation A. This was a
surprising discovery since Formulation A already contained the same
amount of NAT which was used to make Formulation C. Hence, it was
surprisingly discovered that NAT provided an increase to the
potency of the toxin with rHSA which was not provided by NAT to the
HSA toxin formulation.
[0227] (d) the potency of Formulation A (HSA toxin) to which 4
micrograms of zinc chloride was added (to thereby make a
Formulation D) increased to 107 at T.sub.0 and 94 at T.sub.6. This
experiment therefore showed that surprisingly the addition of zinc
increased the potency of Formulation D as compared to Formulation
A. Formulation D was 26% more potent at T.sub.0 than was
Formulation A and Formulation D was 31% more potent at T.sub.6 than
was Formulation A. Thus, the addition of zinc significantly
increased the potency of the HSA toxin formulation.
[0228] (e) the potency of Formulation C to which of 4 micrograms of
zinc chloride was added (to thereby make a Formulation E) increased
the potencies to 116 T.sub.0 and to 99 at T.sub.6. This experiment
therefore showed that the addition of zinc increased the potency of
Formulation E as compared to Formulation C (16% increase at T.sub.0
and 2% increase at T.sub.6). Thus, surprisingly the addition of
zinc by itself increased the potency of the r-HSA formulation.
[0229] Notably, the increase in potency of Formulation E as
compared to Formulation A was 36% at T.sub.0 and 38% at T.sub.6.
Thus, it was surprisingly discovered that the addition of zinc to
the rHSA formulation provided a toxin which was substantially more
potent than was the HSA toxin without zinc formulation (A). Hence,
Formulation E is a most preferred pharmaceutical composition.
[0230] A further Formulation F was made by adding 4 micrograms of
zinc chloride to Formulation B.
1TABLE 1 Botulinum Toxin (Type A Complex) Pharmaceutical
Compositions Formu- Toxin NaCl Albumin Octanoate NAT ZnCl.sub.2 P80
lation (units) (ug) (ug) (ug) (ug) (ug) (ug) A 100 900 500 7 10 0 0
HSA B 100 900 500 13 0 0 0.04 r-HSA C 100 900 500 13 10 0 0.04
r-HSA D 100 900 500 7 10 4 0 HSA E 100 900 500 13 10 4 0.04 r-HSA F
100 900 500 13 0 4 0.04 r-HSA
[0231] The increased potencies of certain botulinum toxin
formulations, as set forth by the experiment above, can be directly
linked to an enhanced stability. In other words, a greater relative
potency of one formulation with regard to another formulation can
mean that one formulation has more botulinum toxin molecules which
retain their biological activity (i.e. are stabilized).
[0232] Thus, my invention encompasses addition of a zinc ion source
to a.botulinum toxin containing pharmaceutical (HSA or rHSA)
formulation to thereby obtain a more potent toxin formulation. As
shown by Formulations D, E and F (vacuum dried before
reconstitution) in FIG. 3, the presence of zinc in the formulations
provided an enhanced potency, at T.sub.0, as compared to the
non-zinc containing formulations (A, B and C) at T.sub.0.
[0233] A further experiment was carried out whereby the potencies
of two versions of Formulation E were determined at T.sub.0. It was
found that vacuum dried and liquid versions (the later not vacuum
or freeze dried)) of Formulation E had statistically identical
potencies (116 vs 115) at T.sub.0. This later experiment showed
therefore that the zinc was not providing a cryo-protectant effect
to the botulinum toxin but that the zinc present was providing a
enhanced potency at T.sub.0 to the zinc containing formulations.
Hence, it was determined that zinc does not provide cryoprotection
to a botulinum toxin during the freeze drying step in the
preparation of a freeze dried botulinum toxin pharmaceutical
composition. Prior to my invention it was not known that zinc can
have a stabilizing function on a botulinum toxin. It can be
postulated that metals, such as divalent metal cations, may be able
to enhance the stability of a freeze-dried formulation due to
various cryo-properties including the lattice structures of formed
ices. Extraneous metals such as copper and iron species lend
themselves to radical oxidations and are generally to be avoided.
It is known that botulinum toxin type A toxin is dependent upon
bound zinc for it's intracellular enzymatic activity. Many of the
art known excipients or reaction products of these excipients,
including albumin, can chelate metals. This could lead to formation
of unstable ices and/or inactivated toxin. By supplying ample zinc
in the formulation the presence of desirable divalent cations is
assured, the likelihood of zinc loss by the toxin is reduced, and
stability enhanced. This can be accomplished by the addition of
ZnSO.sub.4 or ZnCl.sub.2 to a botulinum toxin pharmaceutical
composition.
Example 4
Zinc Containing Botulinum Toxin Pharmaceutical Compositions with
Enhanced Anti-Microbial Activity
[0234] It was determined that the zinc containing formulations D-F
showed anti-microbial activity, as compared to the non-zinc
containing formulations A-C, against the two microorganisms
Escherichia coli and Pseudomonas aeruginosa. Formulations A to F
were assessed by reconstituting samples of each of the six
lyophilized formulations with non-preserved saline (0.9% NaCl for
injection) (1-mL/100 unit vial) followed by storage at room
temperature. Separate 100 unit vials of each of the six
reconstituted formulations were then inoculated to contain
approximately 110-140 one hundred colony-forming units (CFU) per
milliliter of the microorganisms Escherichia coli (ATCC 8739) and
Pseudomonas aeruginosa (ATCC 9027). Solutions were vortexed and
were stored at room temperature (22.5.+-.2.5.degree. C.) for 5
days. At 24 hours, 48 hours, and 5 days after inoculation the
samples were assayed to determine the numbers of viable CFU per
milliliter. Data is presented in logarithmic reductions (-) or
logarithmic increases (+) in Table 2. NR=No Recovery (<10
CFU/mL)
2TABLE 2 Antimicrobial Activity of Six Different Botulinum Toxin
Pharmaceutical Compositions Formu- P. aeruginosa E. coli lation
Time 140 CFU/mL 110 CFU/mL A 24 hrs +1.08 +1.99 48 hrs +2.80 +3.28
5 days +4.17 +4.21 B 24 hrs +0.86 +0.68 48 hrs +2.54 +2.06 5 days
+3.97 +3.98 C 24 hrs +0.56 +0.75 48 hrs +1.48 +1.64 5 days +3.95
+3.76 D 24 hrs -0.10 -0.34 48 hrs 0.00 -0.56 5 days +1.36 NR E 24
hrs -0.30 -0.34 48 hrs +0.08 NR 5 days +2.54 NR F 24 hrs +0.59
+0.26 48 hrs -0.10 NR 5 days +1.69 NR
[0235] The results of this experiment showed that the zinc
containing Formulations D, E, F had-significantly less microbial
growth as compared the non-zinc containing formulations A, B, C,
against the two indicated microorganisms. Prior to my invention it
was unknown that zinc can provide an enhanced antimicrobial
activity to a pharmaceutical active ingredient which is an enzyme,
such as a botulinum toxin. Typically, proteins, and especially
enzymes, do not retain biological activity in the presence of an
anti-microbial agent.
Example 5
Botulinum Toxin Pharmaceutical Composition Containing
2-Hydroxyethyl Starch
[0236] Botulinum toxin type A purified neurotoxin complex
pharmaceutical formulations were prepared in the same manner set
forth in Example 1 above, except that the 0.5 milligrams of albumin
was replaced by either 500 .mu.g or 600 .mu.g of hetastarch. It was
determined that full potency was maintained upon preparation of the
hetastarch containing formulations. Thus, with both hetastarch
containing formulations, the potency of the albumin-free,
hetastarch containing composition, as measured at the time of
reconstitution of the lyophilized, 100 U (.+-.20 U) botulinum toxin
type A complex, was from 96 to 128 units. Three separate
hetastarch, botulinum toxin type A complex pharmaceutical
compositions had potency measurements, at the time of
reconstitution, of, respectively, 105, 111 and 128 units. Potency
was measured using the standard administration to mice toxin
potency assay.
Example 6
Botulinum Toxin Pharmaceutical Composition Containing Glycine
[0237] Botulinum toxin type A purified neurotoxin complex
pharmaceutical formulations was prepared in the same manner set
forth in Example 1 above, except that the 0.5 milligrams of albumin
was replaced by either 500 .mu.g or 600 .mu.g of hetastarch. In
addition 1 mg of glycine was added to the formulation. A
lyophilized, hetastarch plus glycine, albumin-free, 100 U botulinum
toxin type A complex, pharmaceutical composition was then stored
for seven months at -5.degree. C. At the end of this seven month
period the potency of this hetastarch plus glycine toxin
formulation was determined, using the mouse administration assay,
to be essentially unchanged (i.e. potency differed by less than 5%
from the original potency).
Example 7
Botulinum Toxin Pharmaceutical Composition Containing Lysine
[0238] 100 U botulinum toxin type A purified neurotoxin complex
pharmaceutical formulations are prepared in the same manner set
forth in Example 1 above, except that the 0.5 milligrams of albumin
was replaced by 600 .mu.g of hetastarch. In addition 1 mg of lysine
is added to the formulation. A lyophilized, hetastarch plus lysine,
albumin-free, 100 U botulinum toxin type A complex, pharmaceutical
composition is then stored for one year at -5.degree. C. At the end
of this one year period the potency of this hetastarch plus lysine,
toxin formulation is determined, using the mouse administration
assay, to be essentially unchanged (i.e. potency differs by less
than 5% from the original potency).
Example 8
Botulinum Toxin Pharmaceutical Composition Containing Histidine
[0239] 100 U botulinum toxin type A purified neurotoxin complex
pharmaceutical formulations are prepared in the same manner set
forth in Example 1 above, except that the 0.5 milligrams of albumin
was replaced by 600 .mu.g of hetastarch. In addition 1 mg of
histidine is added to the formulation. A lyophilized, hetastarch
plus histidine, albumin-free, 100 U botulinum toxin type A complex,
pharmaceutical composition is then stored for one year at
-5.degree. C. At the end of this one year period the potency of
this hetastarch plus histidine, toxin formulation is determined,
using the mouse administration assay, to be essentially unchanged
(i.e. potency differs by less than 5% from the original
potency).
Example 9
Botulinum Toxin Pharmaceutical Composition Containing Arginine
[0240] 100 U botulinum toxin type A purified neurotoxin complex
pharmaceutical formulations are prepared in the same manner set
forth in Example 1 above, except that the 0.5 milligrams of albumin
was replaced by 600 .mu.g of hetastarch. In addition 1 mg of
arginine is added to the formulation. A lyophilized, hetastarch
plus arginine, albumin-free, 100 U botulinum toxin type A complex,
pharmaceutical composition is then stored for one year at
-5.degree. C. At the end of this one year period the potency of
this hetastarch plus arginine, toxin formulation is determined,
using the mouse administration assay, to be essentially unchanged
(i.e. potency-differs by less than 5% from the original
potency).
Example 10
Botulinum Toxin Pharmaceutical Composition Containing An Amino
Acid
[0241] Botulinum toxin type A purified neurotoxin complex
pharmaceutical formulations can be prepared in the same manner set
forth in Example 1 above, except that the 0.5 milligrams of albumin
can be replaced by about 1 mg of an amino acid such as lysine,
glycine, histidine or arginine. Thus a lyophilized, polysaccharide
free, albumin free, glycine containing, botulinum toxin type A
complex, pharmaceutical composition can be prepared and stored for
at least one year -5.degree. C., and at the end of this period can
have a potency of which is essentially unchanged (i.e. potency can
differ by less than 5% from the original potency).
Example 11
Use of a Botulinum Toxin Pharmaceutical Composition
[0242] A 48 year old male is diagnosed with a spastic muscle
condition, such as cervical dystonia. Between about 10.sup.-3 U/kg
and about 35 U/kg of a botulinum toxin type A pharmaceutical
composition containing 600 .mu.g of hetastarch and 1 mg of an amino
acid, such as lysine, is injected intramuscularly into the patient.
Within 1-7 days the symptoms of the spastic muscle condition are
alleviated and alleviation of the symptoms persists for at least
from about 2 months to about 6 months.
Example 12
Use of a Botulinum Toxin Pharmaceutical Composition to Treat Equine
Colic
[0243] A two year old thoroughbred is brought into a veterinary
clinic for evaluation of a recent onset of poor feeding, fussiness,
and being rider-unfriendly. Blood chemistry indicates that the
horse has metabolic disturbances of low glucose, hyperkalemia, and
low blood count. Urinary excretion indicative of dehydration is
noticed. The horse is diagnosed with colic. A composition
containing between about 10.sup.-3 U/kg and about 35 U/kg of
botulinum toxin A and 600 .mu.g of hetastarch is intrathecally and
transabdominally injected at several sites on three separate office
visits. After three months, all signs of colic disappear and the
horse is reintroduced into the racing circuit.
Example 13
Use of a Botulinum Toxin Pharmaceutical Composition to Treat a
Canine
[0244] An owner of a 3 year-old German shepherd comes to a clinic
concerned about a week history of limping and general lethargy of
her dog. An x-ray is performed and a diagnosis of hip dysplasia is
made. The animal undergoes hip replacement surgery. The dog's hips
are cast, and botulinum toxin A injection is suggested to provide
further immobilization of the rear legs and hips. Multiple
injections of a composition comprising about 20 U/kg of botulinum
toxin type A and 600 .mu.g of hetastarch are given to the animal.
The dog recuperates for about 4 weeks before removal of the cast.
After removal of the cast, the dog continues to rest. A little
after 8 weeks, the dog begins to regain some function of his legs.
After 4 months, the dog has regained enough function to begin
regular walking. By 6 months, the dog resumes normal
activities.
[0245] A year after the hip replacement, the dog is lethargic, does
not eat, and appears to be in distress. The dog is brought to a
veterinarian for diagnosis. Except for low blood glucose, all other
blood chemistry values appear normal. A barium scan of the upper GI
finds narrowing of the lower esophageal sphincter, resulting in a
megaesophagus. Diagnosis of achalasia is made, and botulinum toxin
injection is suggested. An injection of a composition containing
botulinum toxin type. A and hetastarch into the lower esophageal
sphincter muscles is performed using fiberoptic guidance.
Importantly, one week later, a second barium scan is performed,
revealing a complete opening of the sphincter, and indicating that
the dog has not developed immunity to the toxin from his earlier
surgery. The owner notices cessation of vomiting and normal feeding
habits.
Example 14
Use of a Botulinum Toxin Pharmaceutical Composition to Immobilize
an Animal
[0246] A 4 year old angus bull is transported under general
anesthesia to a large animal veterinary clinic facility for an
evaluation of a fractured tibia resulting from a fight with another
bull. X-ray evaluation reveals 3 fracture points restricted to the
right, rear tibia without fractures to the fibula. The shin is
plaster-casted, and it is recommended that the bull be completely
immobilized to allow the leg to heal properly. A composition
containing about 40 U/kg of botulinum toxin A and 600 .mu.g of
hetastarch is injected in several large muscle groups, including
all the limb front and rear limb muscles. No injection is made to
the abdominal rectus, cervical spinal, or facial muscles. The bull
is completely immobilized but retains full functional control over
food intake. After six months and two complete panels of
injections, the limb heals enough to allow weight-bearing, but
restricted movements within its own bull pen. After three more
months the bull is allowed to be with other bulls to resume more
physical activities.
Example 15
Use of a Botulinum Toxin Composition to Treat Canine Muscle
Spasms
[0247] A 10 year old Yorkshire terrier is brought into a clinic for
an evaluation of muscle spasms confined to the right half of the
body. A CAT scan of the head reveals a large, intraparenchymal mass
in the left brain, and biopsy reveals a grade II astrocytoma.
Euthanasia is proposed by the veterinarian.
[0248] However, the owner still wants to spend the last few weeks
of quality time with her dog and does not want the animal to suffer
any pain that may result from the muscle spasms. Botulinum toxin
injection is suggested. Injections are made in spastic musculature
on the right side. The injections successfully abolish all spastic
activities. The dog lives the remaining two weeks without spasms
and according to the owner, happy and "appeared to be rather
healthy".
Example 16
Use of a Botulinum Toxin Pharmaceutical Composition to Treat
Founder
[0249] A four-year-old Welsh mare has been habitually overfed a
rich diet of alfalfa hay. The owner finds the pony hobbling in
obvious pain and unable to walk normally. Upon examination the
veterinarian diagnoses the problem as founder and recommends a
strict diet and regular exercise until the animal's symptoms
subside. However, neither the owner nor the veterinarian can
convince the pony to walk more than a few steps at a time. If
normal exercise is not quickly resumed the animal will be
permanently crippled. A composition containing approximately of 100
U botulinum toxin type A and 500 .mu.g HSA is injected into the
hooves enabling the pony to apply pressure to the previously
painful area. Within two weeks the pony regains its normal gait and
resumes pulling a small cart containing the owner's children.
Example 17
Multiple Component Botulinum Toxin Formulations
[0250] As set forth briefly in the Definitions sections supra under
the definition of "Pharmaceutical Composition" a multiple (i.e. two
or more) component system for the making of a final formulation can
provide the benefit of allowing incorporation of ingredients which
are not sufficiently compatible for long-term shelf storage with
the first component of the two component system or which for other
reasons it is not desirable to include with the first component of
the pharmaceutical composition. In this manner what I refer to as
adaptive neurotoxin (i.e botulinum toxin) formulations can be
prepared.
[0251] rHSA and HSA can require secondary stabilizers such as
N-Acetyltryptophan, sodium caprylate, fatty acids, surfactants and
divalent cations for optimum long-term stability. Studies utilizing
probe formulations indicate that some of these secondary
stabilizers may induce enhanced potency or stability on neurotoxin
(i.e botulinum toxin) formulations. This example sets forth a way
to add the appropriate concentration of these ingredients to obtain
the desired effect. One way to accomplish this is to include the
ingredient in the base formulation. Another is to add it to a base
formulation prior to use. As set forth herein, Zinc, for example,
may enhance the potency or liquid stability when added to an
existing neurotoxin (i.e botulinum toxin) formulation not
containing zinc. Other beneficial stabilizing ingredients can
likewise be added in this manner.
[0252] A limitation of the current Botox.RTM. formulation is
related to the useful length of the product. Currently the
recommended (for sterility reasons) life after reconstitution of
Botox.RTM. is about four hours. This is due to the fact that the
product contains no preservative. The diluent, saline, also
contains no preservative. Studies indicate that incorporation of
some preservatives can degrade the toxin over a long storage time
(i.e. up to 2 years) of the vacuum dried product. However,
utilization of a diluent containing a preservative would expose the
toxin to degradation processes for a much shorter time while still
providing preservative efficacy, that is the time of use, and
thereby allow incorporation of a preservative.
[0253] A problem related to removal of protein stabilizers is
clinical performance.
[0254] Studies with hetastarch stabilized formulations indicate
differences in performance (safety profile) possibly related to
diffusion characteristics of the HES when compared to HSA. Other
stabilizers (such as povidone) which perform similarly to HSA have
thus far proven incompatible during storage, thereby limiting their
usefulness. Incorporating them into a diluent or reconstitution
vehicle would eliminate long-term exposure of the toxin to the
incompatible species during which such degradation could occur.
Therefore a HES or saline vacuum-dried formulation could be
reconstituted in a vehicle containing a carrier, such as povidone,
providing a shelf-stable product with the desired clinical
performance.
[0255] Buffer salts or physiological pH conditions also may cause
degradation during long-term storage. Enhanced storage stability
may only be achievable by providing a suitable pH environment not
suitable for injection (burning/stinging), such as low pH. A
two-part system would overcome these limitations. A low pH
shelf-stable formulation could be diluted or reconstituted using a
buffer to overwhelm the capacity of the first composition, thereby
providing a comfortable physiologic pH for injection.
[0256] Other advantages allow for changing the vehicle depending on
use; i.e., the carrier could be selected according to the desired
clinical diffusion characteristics. For example, toxin vacuum-dried
in SWI, reconstituted with HES for one indication (cosmetic) and
HSA for another (therapeutic). Stabilizing the toxin in SWFI, then
reconstituting with saline (to obtain isotonicity) is another
formulation option.
[0257] The final formulation might also be adapted to provide for
patients allergic to a particular ingredient (a collagen vehicle
substituted for a patient allergic to gelatin, for example).
Otherwise, the base toxin formulation could be reconstituted with
different albumins derived from a particular species for use in
veterinary applications (equine serum albumin for use in horses,
bovine serum albumin for use in cattle, as examples).
[0258] The basis of the invention is a formulation combined with
adaptive, specialized vehicles/diluents to obtain the desired
characteristics. The product can consist of three (or more)
components; e.g., a vial containing a stable solid toxin and two
pre-filled syringes containing differently formulated
reconstitution vehicles.
[0259] Examples of Three-Component Systems:
[0260] Version I (Solid/Liquid):
[0261] 1. Toxin vacuum dried in NaCl
[0262] 2. Reconstitution vehicle containing HSA or rHA
[0263] 3. Second reconstitution vehicle containing HES
[0264] (recon with rHA to obtain Botox safety profile/HES to obtain
modulated safety profile)
[0265] Version II (Solid/Liquid):
[0266] 1. Toxin vacuum dried in NaCl
[0267] 2. Reconstitution vehicle containing Povidone
[0268] 3. Second reconstitution vehicle containing HES
[0269] (reconstitute with Povidone to obtain Botox safety
profile/HES to obtain modulated safety profile)
[0270] Version III (Solid/Liquid):
[0271] 1. Toxin vacuum dried in SWFI (sterile water for
injection)
[0272] 2. Reconstitution vehicle containing Povidone
[0273] 3. Second reconstitution vehicle containing HES
[0274] (reconstitute with Povidone to obtain Botox safety
profile/HES to obtain modulated safety profile)
[0275] Version IV (liquid/liquid):
[0276] 1. Toxin liquid stabilized with a buffer at pH 4
[0277] 2. Diluent liquid buffered to pH 7 containing HSA
[0278] 3. Second diluent liquid buffered to pH 7 containing HES
[0279] (dilute with HSA diluent to obtain Botox safety profile/HES
to obtain modulated safety profile)
[0280] Version VI (Solid/Liquid):
[0281] 1. Toxin vacuum dried in SWFI (sterile water for
injection)
[0282] 2. Reconstitution vehicle containing HSA or rHA and
preservative
[0283] 3. Second reconstitution vehicle containing HES and
preservative
[0284] (reconstitute with HSA/rHA to obtain Botox safety
profile/HES to obtain modulated safety profile; preservative is
compatible with toxin to retain potency during specified time of
use (e.g., 48 hours))
[0285] A pharmaceutical composition according to the invention
disclosed herein has many advantages, including the following:
[0286] 1. the pharmaceutical composition can be prepared free of
any blood product, such as albumin and therefore free of any blood
product infectious element such as a prion.
[0287] 2. the pharmaceutical composition has stability and high %
recovery of toxin potency comparable to or superior to that
achieved with currently available pharmaceutical compositions.
[0288] Accordingly, the pharmaceutical compositions disclosed
herein have reduced immunogenicity and therefore enable medical
caregivers to treat animals with a reduced risk that the animal
will develop an immune response to the administered
composition.
[0289] Various publications and/or references have been cited
herein, the contents of which, in their entireties, are
incorporated herein by reference.
[0290] Although the present invention has been described in detail
with regard to certain preferred methods, other embodiments,
versions, and modifications within the scope of the present
invention are possible. For example, a wide variety of stabilizing
polysaccharides and amino acids are within the scope of the present
invention.
[0291] Accordingly, the spirit and scope of the following claims
should not be limited to the descriptions of the preferred
embodiments set forth above.
* * * * *
References