Patent Publication Number: US-2022211649-A1

Title: Stable aqueous capsaicin injectable formulations and medical uses thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 17/018,148, filed Sep. 11, 2020, which is a continuation of U.S. patent application Ser. No. 16/695,824, filed Nov. 26, 2019, now U.S. Pat. No. 10,772,853, which is a continuation of U.S. patent application Ser. No. 16/400,278, filed May 1, 2019, now U.S. Pat. No. 10,493,047, which is a continuation of International (PCT) Patent Application Serial No. PCT/US2017/059628, filed Nov. 2, 2017, which claims the benefit of and priority to U.S. Provisional Patent Application Ser. No. 62/416,345, filed Nov. 2, 2016; the entire contents of these applications are incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     The invention provides stable, aqueous capsaicin injectable formulations, a unit dose containing such injectable formulations, medical kits, and methods for using such injectable formulations and unit doses to treat patients suffering from pain, such as osteoarthritic knee pain. 
     BACKGROUND 
     Pain can function as a protective mechanism that allows healthy human beings and animals to avoid tissue damage and/or prevent further damage to injured tissue. However, there are many instances in which pain persists beyond its usefulness. Such unnecessary suffering from pain can impair a subject&#39;s physical mobility, mental performance, and even contribute to depression. 
     Substantial resources have been devoted over the years to researching the causes of various types of pain and to the development of medicine to attenuate pain experienced by a patient. Exemplary classes of common pain-relief medications include opioids, non-steroidal anti-inflammatory agents, corticosteroids, and centrally acting agents such as anti-depressants, anti-epileptics, pregabalin, and gabapentin. Capsaicin has been described for use in treating pain. See, for example, U.S. Pat. Nos. 5,962,532; 8,420,600; 8,367,733; and 8,158,682. Certain commercial products containing capsaicin for pain relief formulate the capsaicin as a cream (e.g., Capzasin) or in a patch (e.g., a capsaicin-containing transdermal patch marketed under the trade name QUTENZA®) for topical application to the skin of a patient. 
     Because capsaicin is soluble in organic solvents, but poorly soluble in water, new formulations are needed for achieving a desirable amount of capsaicin dissolved in an aqueous formulation that is suitable for injection into a patient, and which has suitable stability for use in typical distribution routes for delivering pharmaceutical agents to medical facilities which typically involve storage of the formulation for certain lengths of time. The present invention addresses the foregoing need and provides other related advantages. 
     SUMMARY 
     The invention provides stable, aqueous capsaicin injectable formulations, a unit dose containing such injectable formulations, medical kits, and methods for using such injectable formulations and unit doses to treat patients suffering from pain, such as osteoarthritic knee pain. The invention is based in part on the discovery that a solubilizing agent containing a polyethylene glycol ester of a long-chain hydroxyalkanoic acid or a polyethylene glycol ester of a long-chain hydroxyalkenoic acid (such as a mixture containing a polyethylene glycol ester of 12-hydroxystearic acid, a polyethylene glycol ester of 12-((12-hydroxyoctadecanoyl)oxy)octadecanoic acid, and polyethylene glycol sold by BASF under the trade name KOLLIPHOR® HS 15) was able to solubilize greater amounts of capsaicin than other tested solubilizing agents in the aqueous medium at the desired pH range, and yet produced a formulation suitable for injection to a patient and that is sufficiently stable to storage that it may be used in the typical distribution routes for pharmaceutical agents. Further illustrative benefits of the injectable formulations of the invention are the multiple benefits provided by the above-cited solubilizing agent relative to use of a polysorbate to create a stable, aqueous capsaicin injectable formulation suitable for administration to a patient. The solubilizing agent used in the invention formulations is superiorly compatible with capsaicin, which improves the stability of the formulation to storage. By contrast, polysorbates, such as Polysorbate 80, can have a greater propensity to form peroxides. Such peroxides can cause undesired oxidation of capsaicin, resulting in loss of capsaicin during storage of the formulation and increase in the amount and identity of impurities. The solubilizing agent specified above in the formulations of the invention overcomes this deficiency of polysorbate. Accordingly, the formulations provide the benefit that they achieve elevated levels of dissolved capsaicin in an aqueous medium suitable for injection directly into a patient, and the formulations are stable to storage. 
     The stable, aqueous capsaicin injectable formulations described above for capsaicin may be used more generally to solubilize a vanilloid receptor agonist for administration by to a patient by injection or other route. Accordingly, another aspect of the invention provides a stable, aqueous injectable formulation containing a vanilloid receptor agonist, such as resiniferatoxin. Such formulations may be used in a unit dose form, in medical kits, and in methods for treating patients suffering from pain, such as osteoarthritic knee pain. 
     Various aspects and embodiments of the invention are described in further detail below. For example, one aspect of the invention provides an aqueous, capsaicin injectable formulation, comprising:
         a. about 0.03% (w/w) to about 0.3% (w/w) of capsaicin;   b. about 0.1% (w/w) to about 3% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, (ii) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkenoic acid, or (iii) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group;   c. about 0.001% (w/w) to about 2% (w/w) of an antioxidant; and   d. at least 92% (w/w) water.       

     More specific embodiments include, for example, formulations where the solubilizing agent comprises a (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H, (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H, and polyethylene glycol. In certain embodiments, the formulation may be further characterized according to, for example, its stability to storage, such as where less than 1% of the capsaicin degrades upon storage of the formulation at 40° C. for 24 weeks. Additional description of injectable formulations is provided in the detailed description, along with specific illustrative injectable formulations. 
     Another aspect of the invention provides a unit dosage form comprising a formulation described herein, such as a formulation in any one of Tables 1-5. The unit dosage form may be further characterized according to, for example, the volume of the unit dosage form, such as where the unit dosage form has a volume in the range of about 0.5 mL to about 3 mL, or more preferably about 2 mL. 
     Another aspect of the invention provides a method of treating pain in a patient, where the method comprises administering to a patient in need thereof a therapeutically effective amount of a formulation described herein, such as a formulation in any one of Tables 1-5, to a site at or near the location of pain, in order to treat the pain. The pain may be joint pain, such as where the joint is a knee joint, hip joint, shoulder joint, elbow joint, carpal joint, tarsal joint, or metatarsal joint. In certain embodiments, the joint is affected by osteoarthritis. In a preferred embodiment, the pain is pain in a knee joint affected by osteoarthritis. In other embodiments, the pain is pain in or around soft tissue. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention provides stable, aqueous capsaicin injectable formulations, a unit dose containing such injectable formulations, medical kits, and methods for using such injectable formulations and unit doses to treat patients suffering from pain, such as osteoarthritic knee-joint pain. The invention is based in part on the discovery that a solubilizing agent containing a polyethylene glycol ester of a long-chain hydroxyalkanoic acid or a polyethylene glycol ester of a long-chain hydroxyalkenoic acid (such as a mixture containing a polyethylene glycol ester of 12-hydroxystearic acid, a polyethylene glycol ester of 12-((12-hydroxyoctadecanoyl)oxy)octadecanoic acid, and polyethylene glycol sold by BASF under the tradename KOLLIPHOR® HS 15) was able to solubilize greater amounts of capsaicin than other tested solubilizing agents in the aqueous medium at the desired pH range, and yet produced a formulation suitable for injection to a patient and that is sufficiently stable to storage that it may be used in the typical distribution routes for pharmaceutical agents. Further illustrative benefits of the injectable formulations of the invention are the multiple benefits provided by the above-cited solubilizing agent relative to use of a polysorbate to create a stable, aqueous capsaicin injectable formulation suitable for administration to a patient. The solubilizing agent used in the invention formulations is superiorly compatible with capsaicin, which improves the stability of the formulation to storage. By contrast, polysorbates, such as Polysorbate 80, can have a greater propensity to form peroxides. Such peroxides can cause undesired oxidation of capsaicin, resulting in loss of capsaicin during storage of the formulation and increase in the amount and identity of impurities. The solubilizing agent specified above in the formulations of the invention overcomes this deficiency of polysorbate. Accordingly, the formulations provide the benefit that they achieve elevated levels of dissolved capsaicin in an aqueous medium suitable for injection directly into a patient, and the formulations are stable to storage. 
     The stable, aqueous capsaicin injectable formulations described above for capsaicin may be used more generally to solubilize a vanilloid receptor agonist for administration by injection or other route. Accordingly, another aspect of the invention provides a stable, aqueous injectable formulation containing a vanilloid receptor agonist, such as resiniferatoxin. Such formulations may be used in a unit dose form, in medical kits, and in methods for treating patients suffering from pain, such as osteoarthritic knee pain. 
     Various aspects of the invention are set forth below in sections; however, aspects of the invention described in one particular section are not to be limited to any particular section. 
     I. Definitions 
     To facilitate an understanding of the present invention, a number of terms and phrases are defined below. 
     The terms “a” and “an” as used herein mean “one or more” and include the plural unless the context is inappropriate. 
     The term “about” means within 10% of the stated value. In certain embodiments, the value may be within 8%, 6%, 4%, 2%, or 1% of the stated value. 
     The term “alkyl” as used herein refers to a saturated straight or branched hydrocarbon, such as a straight or branched group of 1-12, 1-10, or 1-6 carbon atoms, referred to herein as C 1 -C 12 alkyl, C 1 -C 10 alkyl, and C 1 -C 6 alkyl, respectively. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, propyl, isopropyl, 2-methyl-1-propyl, 2-methyl-2-propyl, 2-methyl-1-butyl, 3-methyl-1-butyl, 2-methyl-3-butyl, 2,2-dimethyl-1-propyl, 2-methyl-1-pentyl, 3-methyl-1-pentyl, 4-methyl-1-pentyl, 2-methyl-2-pentyl, 3-methyl-2-pentyl, 4-methyl-2-pentyl, 2,2-dimethyl-1-butyl, 3,3-dimethyl-1-butyl, 2-ethyl-1-butyl, butyl, isobutyl, t-butyl, pentyl, isopentyl, neopentyl, hexyl, heptyl, octyl, etc. 
     The term “hydroxyalkyl” refers to an alkyl group substituted by 1 or 2 hydroxyl groups. In certain embodiments, the hydroxyalkyl is an alkyl group substituted by only 1 hydroxyl group. 
     The term “hydroxyalkanoic acid” refers to saturated straight or branched hydrocarbon that is substituted by (i) one —CO 2 H group, and (ii) one or two hydroxyl groups. 
     The term “alkenyl” as used herein refers to an unsaturated straight or branched hydrocarbon having at least one carbon-carbon double bond, such as a straight or branched group of 2-12, 2-10, or 2-6 carbon atoms, referred to herein as C 2 -C 12 alkenyl, C 2 -C 10 alkenyl, and C 2 -C 6 alkenyl, respectively. Exemplary alkenyl groups include vinyl, allyl, butenyl, pentenyl, hexenyl, butadienyl, pentadienyl, hexadienyl, 2-ethylhexenyl, 2-propyl-2-butenyl, 4-(2-methyl-3-butene)-pentenyl, and the like. 
     The term “hydroxyalkenyl” refers to an alkenyl group substituted by 1 or 2 hydroxyl groups. In certain embodiments, the hydroxyalkenyl is an alkenyl group substituted by only 1 hydroxyl group. 
     The term “hydroxyalkenoic acid” refers to an unsaturated straight or branched hydrocarbon having one carbon-carbon double bond, wherein the hydrocarbon is substituted by (i) one —CO 2 H group, and (ii) one or two hydroxyl groups. 
     The term “polyethylene glycolyl” refers to a radical of polyethylene glycol. The polyethylene glycolyl is a chemical fragment that is part of a larger molecule. When the polyethylene glycolyl is bonded at one location to the remainder of the molecule, then the polyethylene glycolyl is a mono-radical, such as “—(CH 2 CH 2 O)x-H” where x is an integer greater than 1. When the polyethylene glycolyl is used as a component within a molecule connecting two fragments of the molecule, the polyethylene glycolyl is a diradical, having a point of attachment at each terminus of the polyethylene glycolyl, which may be illustrated as “—(CH 2 CH 2 O)x-” where x is an integer greater than 1. In certain embodiments, x is an integer in the range of about 5 to about 100, about 5 to about 50, about 5 to about 25, about 5 to about 15, about 10 to about 50, about 10 to about 30, or about 10 to about 20. In certain embodiments, x is about 10, 11, 12, 13, 14, 15, 16, 17, 18, or 19. In certain preferred embodiments, x is about 15. 
     Macrogol 15 hydroxystearate has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15. 
     The compounds of the disclosure may contain one or more chiral centers and/or double bonds and, therefore, exist as stereoisomers, such as geometric isomers, enantiomers or diastereomers. The term “stereoisomers” when used herein consist of all geometric isomers, enantiomers or diastereomers. These compounds may be designated by the symbols “R” or “S,” depending on the configuration of substituents around the stereogenic carbon atom. The present invention encompasses various stereoisomers of these compounds and mixtures thereof. Stereoisomers include enantiomers and diastereomers. Mixtures of enantiomers or diastereomers may be designated “(±)” in nomenclature, but the skilled artisan will recognize that a structure may denote a chiral center implicitly. It is understood that graphical depictions of chemical structures, e.g., generic chemical structures, encompass all stereoisomeric forms of the specified compounds, unless indicated otherwise. 
     Individual stereoisomers of compounds of the present invention can be prepared synthetically from commercially available starting materials that contain asymmetric or stereogenic centers, or by preparation of racemic mixtures followed by resolution methods well known to those of ordinary skill in the art. These methods of resolution are exemplified by (1) attachment of a mixture of enantiomers to a chiral auxiliary, separation of the resulting mixture of diastereomers by recrystallization or chromatography and liberation of the optically pure product from the auxiliary, (2) salt formation employing an optically active resolving agent, or (3) direct separation of the mixture of optical enantiomers on chiral chromatographic columns. Stereoisomeric mixtures can also be resolved into their component stereoisomers by well-known methods, such as chiral-phase gas chromatography, chiral-phase high performance liquid chromatography, crystallizing the compound as a chiral salt complex, or crystallizing the compound in a chiral solvent. Specific stereoisomers can also be obtained selectively using stereomerically pure intermediates, reagents, and catalysts by well-known asymmetric synthetic methods. 
     Geometric isomers can also exist in the compounds of the present invention. The symbol   denotes a bond that may be a single, double or triple bond as described herein. The present invention encompasses the various geometric isomers and mixtures thereof resulting from the arrangement of substituents around a carbon-carbon double bond or arrangement of substituents around a carbocyclic ring. Substituents around a carbon-carbon double bond are designated as being in the “Z” or “E” configuration wherein the terms “Z” and “E” are used in accordance with IUPAC standards. Unless otherwise specified, structures depicting double bonds encompass both the “E” and “Z” isomers. 
     Substituents around a carbon-carbon double bond alternatively can be referred to as “cis” or “trans,” where “cis” represents substituents on the same side of the double bond and “trans” represents substituents on opposite sides of the double bond. The arrangement of substituents around a carbocyclic ring are designated as “cis” or “trans.” The term “cis” represents substituents on the same side of the plane of the ring and the term “trans” represents substituents on opposite sides of the plane of the ring. Mixtures of compounds wherein the substituents are disposed on both the same and opposite sides of plane of the ring are designated “cis/trans.” 
     As used herein, the terms “subject” and “patient” refer to organisms to be treated by the methods of the present invention. Such organisms are preferably mammals (e.g., murines, simians, equines, bovines, porcines, canines, felines, and the like), and more preferably humans. 
     As used herein, the term “effective amount” refers to the amount of a compound (e.g., a compound of the present invention) sufficient to effect beneficial or desired results. An effective amount can be administered in one or more administrations, applications or dosages and is not intended to be limited to a particular formulation or administration route. As used herein, the term “treating” includes any effect, e.g., lessening, reducing, modulating, ameliorating or eliminating, that results in the improvement of the condition, disease, disorder, and the like, or ameliorating a symptom thereof. 
     As used herein, the term “pharmaceutically acceptable salt” refers to any pharmaceutically acceptable salt (e.g., acid or base) of a compound of the present invention which, upon administration to a subject, is capable of providing a compound of this invention or an active metabolite or residue thereof. As is known to those of skill in the art, “salts” of the compounds of the present invention may be derived from inorganic or organic acids and bases. Examples of acids include, but are not limited to, hydrochloric, hydrobromic, sulfuric, nitric, perchloric, fumaric, maleic, phosphoric, glycolic, lactic, salicylic, succinic, toluene-p-sulfonic, tartaric, acetic, citric, methanesulfonic, ethanesulfonic, formic, benzoic, malonic, naphthalene-2-sulfonic, benzenesulfonic acid, and the like. Other acids, such as oxalic, while not in themselves pharmaceutically acceptable, may be employed in the preparation of salts useful as intermediates in obtaining the compounds of the invention and their pharmaceutically acceptable acid addition salts. 
     Examples of bases include, but are not limited to, alkali metal (e.g., sodium) hydroxides, alkaline earth metal (e.g., magnesium) hydroxides, ammonia, and compounds of formula NW 3 , wherein W is C 1-4  alkyl, and the like. 
     Examples of salts include, but are not limited to: acetate, adipate, alginate, aspartate, benzoate, benzenesulfonate, bisulfate, butyrate, citrate, camphorate, camphorsulfonate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, flucoheptanoate, glycerophosphate, hemisulfate, heptanoate, hexanoate, hydrochloride, hydrobromide, hydroiodide, 2-hydroxyethanesulfonate, lactate, maleate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, oxalate, palmoate, pectinate, persulfate, phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, tosylate, undecanoate, and the like. Other examples of salts include anions of the compounds of the present invention compounded with a suitable cation such as Na + , NH 4   + , and NW 4   +  (wherein W is a C 1-4  alkyl group), and the like. 
     For therapeutic use, salts of the compounds of the present invention are contemplated as being pharmaceutically acceptable. However, salts of acids and bases that are non-pharmaceutically acceptable may also find use, for example, in the preparation or purification of a pharmaceutically acceptable compound. 
     Throughout the description, where compositions and kits are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are compositions and kits of the present invention that consist essentially of, or consist of, the recited components, and that there are processes and methods according to the present invention that consist essentially of, or consist of, the recited processing steps. 
     As a general matter, compositions specifying a percentage are by weight unless otherwise specified. Further, if a variable is not accompanied by a definition, then the previous definition of the variable controls. 
     II. Aqueous Injectable Formulations 
     One aspect of the invention provides aqueous, injectable formulations. The formulations provide the benefits that they are stable to storage and can be administered directly to a patient via injection. The formulations contain a solubilizing agent to achieve the desired higher concentration of vanilloid receptor agonist in the aqueous medium. The formulations are particularly useful for administering capsaicin by injection to a patient. 
     As indicated above, the invention is based in part on the discovery that a solubilizing agent containing a polyethylene glycol ester of a long-chain hydroxyalkanoic acid or a polyethylene glycol ester of a long-chain hydroxyalkenoic acid (such as a mixture containing a polyethylene glycol ester of 12-hydroxystearic acid, a polyethylene glycol ester of 12-((12-hydroxyoctadecanoyl)oxy)octadecanoic acid, and polyethylene glycol sold by BASF under the trade name KOLLIPHOR® HS 15) was able to solubilize greater amounts of capsaicin than other tested solubilizing agents in the aqueous medium at the desired pH range, and yet produced a formulation suitable for injection to a patient and that is sufficiently stable to storage that it may be used in the typical distribution routes for pharmaceutical agents. Further illustrative benefits of the injectable formulations of the invention are the multiple benefits provided by the above-cited solubilizing agent relative to use of a polysorbate to create a stable, aqueous capsaicin injectable formulation suitable for administration to a patient. The solubilizing agent used in the invention formulations is superiorly compatible with capsaicin, which improves the stability of the formulation to storage. By contrast, polysorbates, such as Polysorbate 80, can have a greater propensity to form peroxides. Such peroxides can cause undesired oxidation of capsaicin, resulting in loss of capsaicin during storage of the formulation and increase in the amount and identity of impurities. The solubilizing agent specified above in the formulations of the invention overcomes this deficiency of polysorbate. Additionally, the solubilizing agent used in the invention formulations overcomes the adverse side effect of polysorbates, such as Polysorbate 80, of triggering release of histamine when administered to a patient. Accordingly, the specific solubilizing agent described herein for use in the invention formulations imparts multiple benefits. 
     Additional features of the aqueous injectable formulations are described below. 
     One aspect of the invention provides an aqueous, capsaicin injectable formulation, wherein the formulation comprises
         a. about 0.03% (w/w) to about 0.3% (w/w) of capsaicin;   b. about 0.1% (w/w) to about 3% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, (ii) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkenoic acid, or (iii) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group;   c. about 0.001% (w/w) to about 2% (w/w) of an antioxidant; and   d. at least 92% (w/w) water.       

     Another aspect of the invention provides an aqueous, capsaicin injectable formulation, wherein the formulation comprises
         a. about 0.01% (w/w) to about 0.5% (w/w) of capsaicin;   b. about 0.01% (w/w) to about 5% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, (ii) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkenoic acid, or (iii) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group; and   c. water.       

     Another aspect of the invention provides an aqueous, vanilloid receptor agonist injectable formulation, wherein the formulation comprises
         a. a vanilloid receptor agonist (e.g., about 0.001% (w/w) to about 5% (w/w) of the vanilloid receptor agonist);   b. about 0.01% (w/w) to about 5% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, (ii) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkenoic acid, or (iii) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group; and   c. water.       

     Another aspect of the invention provides an aqueous, capsaicin injectable formulation, wherein the formulation comprises
         a. about 0.03% (w/w) to about 0.3% (w/w) of capsaicin;   b. about 0.1% (w/w) to about 3% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, (ii) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkenoic acid, or (iii) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group; and   c. at least 92% (w/w) water.       

     Another aspect of the invention provides an aqueous, capsaicin injectable formulation, wherein the formulation comprises
         a. about 0.03% (w/w) to about 0.1% (w/w) of capsaicin;   b. about 0.5% (w/w) to about 1.5% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, or (ii) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group; and   c. at least 92% (w/w) water.       

     Exemplary components and features of the aqueous injectable formulations are described in more detail below. 
     Amount of Solubilizing Agent 
     The formulation can be further characterized according to the amount of solubilizing agent in the formulation. For example, in certain embodiments, the formulation comprises about 0.5% (w/w) to about 1.5% (w/w) of the solubilizing agent. In certain other embodiments, the formulation comprises about 0.8% (w/w) to about 1.2% (w/w) of the solubilizing agent. In certain other embodiments, the formulation comprises about 1% (w/w) of the solubilizing agent. In certain other embodiments, the formulation comprises about 1.5% (w/w) to about 2.5% (w/w) of the solubilizing agent. In certain other embodiments, the formulation comprises about 2% (w/w) of the solubilizing agent. 
     Identity of Solubilizing Agent 
     The formulation can be further characterized according to the identity of the solubilizing agent in the formulation. For example, in certain embodiments, the solubilizing agent comprises (i) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid, or (ii) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkenoic acid. In certain embodiments, the solubilizing agent comprises a (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H. In certain embodiments, the solubilizing gent comprises a (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H, (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H, and polyethylene glycol. In certain embodiments, the solubilizing agent comprises (a) from about 60% (w/w) to about 80% (w/w) of a mixture of (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) from about 20% (w/w) to about 40% (w/w) polyethylene glycol. In certain embodiments, the solubilizing agent comprises (a) about 70% (w/w) of a mixture of (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) about 30% (w/w) polyethylene glycol. In certain embodiments, the solubilizing agent is a mixture of (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H, (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H, and polyethylene glycol. In certain embodiments, the solubilizing agent is a mixture of (a) from about 60% (w/w) to about 80% (w/w) of a mixture of (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) from about 20% (w/w) to about 40% (w/w) polyethylene glycol. In certain embodiments, the solubilizing agent is a mixture of (a) about 70% (w/w) of a mixture of (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) about 30% (w/w) polyethylene glycol. 
     In certain embodiments, the solubilizing agent comprises (a) a polyethylene glycol ester of a (C 15 -C 25 ) hydroxyalkanoic acid and (b) a polyethylene glycol ester of a (C 15 -C 25 ) alkanoic acid substituted by a —OC(O)(C 14 -C 24 ) hydroxyalkyl group, wherein the mole ratio of (a) to (b) is in the range of 10:1 to 1:10, 5:1 to 1:5, 2:1 to 1:2, 10:1 to 5:1, 5:1 to 2:1, 2:1 to 1:1, 1:1 to 1:2, 1:2 to 1:5, 1:5 to 1:10, or is greater than 10:1, or less than 1:1. 
     In a more specific embodiment, the solubilizing agent comprises a (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H. In certain embodiments, the solubilizing agent comprises a (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H, (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H, and polyethylene glycol. In certain embodiments, the solubilizing agent comprises (a) from about 60% (w/w) to about 80% (w/w) of a mixture of (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) from about 20% (w/w) to about 40% (w/w) polyethylene glycol. In certain embodiments, the solubilizing agent comprises (a) about 70% (w/w) of a mixture of (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) about 30% (w/w) polyethylene glycol. In certain embodiments, the solubilizing agent is a mixture of (a) from about 60% (w/w) to about 80% (w/w) of a mixture of (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) from about 20% (w/w) to about 40% (w/w) polyethylene glycol. In certain embodiments, the solubilizing agent is a mixture of (a) about 70% (w/w) of a mixture of (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H and (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H, and (b) about 30% (w/w) polyethylene glycol. 
     In certain embodiments, the mole ratio of (a) (C 14 -C 24 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H to (b) (C 14 -C 24 )hydroxyalkyl-CO 2 —(C 14 -C 24 )alkylene-CO 2 -(polyethylene glycolyl)-H in the formulation is in the range of 10:1 to 1:10, 5:1 to 1:5, 2:1 to 1:2, 10:1 to 5:1, 5:1 to 2:1, 2:1 to 1:1, 1:1 to 1:2, 1:2 to 1:5, 1:5 to 1:10, or is greater than 10:1, or less than 1:1. In certain embodiments, the mole ratio of (a) (C 17 )hydroxyalkyl-CO 2 -(polyethylene glycolyl)-H to (b) (C 17 )hydroxyalkyl-CO 2 —(C 17 )alkylene-CO 2 -(polyethylene glycolyl)-H in the formulation is in the range of 10:1 to 1:10, 5:1 to 1:5, 2:1 to 1:2, 10:1 to 5:1, 5:1 to 2:1, 2:1 to 1:1, 1:1 to 1:2, 1:2 to 1:5, 1:5 to 1:10, or is greater than 10:1, or less than 1:1. 
     In a more specific embodiment, the solubilizing agent comprises 
     
       
         
         
             
             
         
       
     
     In another more specific embodiment, the solubilizing agent is a mixture of 
     
       
         
         
             
             
         
       
     
     and polyethylene glycol. In certain other embodiments, the solubilizing agent comprises (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol. In certain other embodiments, the solubilizing agent is a mixture of (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol. In certain other embodiments, the solubilizing agent comprises (a) from 68% (w/w) to 72% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) from 28% (w/w) to 32% (w/w) polyethylene glycol. 
     In certain embodiments, the mole ratio of (a) 
     
       
         
         
             
             
         
       
     
     in the formulation is in the range of 10:1 to 1:10, 5:1 to 1:5, 2:1 to 1:2, 10:1 to 5:1, 5:1 to 2:1, 2:1 to 1:1, 1:1 to 1:2, 1:2 to 1:5, 1:5 to 1:10, or is greater than 10:1, or less than 1:1. 
     The above solubilizing agent can be further characterized according to the weight-average molecular weight of any polyethylene glycolyl component. For example, in certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 100 g/mol to about 3000 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 200 g/mol to about 1500 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 200 g/mol to about 1000 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 300 g/mol to about 900 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 500 g/mol to about 800 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 600 g/mol to about 750 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 600 g/mol to about 700 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 100 g/mol to about 300 g/mol, about 300 g/mol to about 500 g/mol, about 500 g/mol to about 1000 g/mol, about 1000 g/mol to about 1500 g/mol, about 1500 g/mol to about 2000 g/mol, or about 2000 g/mol to about 2500 g/mol. 
     The above solubilizing agent can be further characterized according to the weight-average molecular weight of any polyethylene glycol component. For example, in certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 100 g/mol to about 3000 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 200 g/mol to about 1500 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 200 g/mol to about 1000 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 300 g/mol to about 900 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 500 g/mol to about 800 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 600 g/mol to about 750 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 600 g/mol to about 700 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight of about 660 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 100 g/mol to about 300 g/mol, about 300 g/mol to about 500 g/mol, about 500 g/mol to about 1000 g/mol, about 1000 g/mol to about 1500 g/mol, about 1500 g/mol to about 2000 g/mol, or about 2000 g/mol to about 2500 g/mol. 
     In yet other embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 100 g/mol to about 3000 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 200 g/mol to about 1500 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 200 g/mol to about 1000 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 300 g/mol to about 900 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 500 g/mol to about 800 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 600 g/mol to about 750 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 600 g/mol to about 700 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight of about 660 g/mol. In certain embodiments, any polyethylene glycol or polyethylene glycolyl each independently have a weight-average molecular weight in the range of about 100 g/mol to about 300 g/mol, about 300 g/mol to about 500 g/mol, about 500 g/mol to about 1000 g/mol, about 1000 g/mol to about 1500 g/mol, about 1500 g/mol to about 2000 g/mol, or about 2000 g/mol to about 2500 g/mol. 
     Antioxidant 
     The formulation can be further characterized according to the antioxidant in the formulation. For example, in certain embodiments, the formulation comprises about 0.005% (w/w) to about 0.1% (w/w) of an antioxidant. In certain embodiments, the formulation comprises about 0.01% (w/w) of an antioxidant. In certain embodiments, the antioxidant is an organic compound. In certain embodiments, the antioxidant is a substituted phenol. In certain embodiments, the antioxidant is a phenolic antioxidant. In certain embodiments, the antioxidant is dibutylhydroxytoluene. 
     Chelating Agent 
     The formulation may optionally further comprise a chelating agent. Accordingly, in certain embodiments, the formulation further comprises a chelating agent. In certain embodiments, the formulation comprises about 0.001% (w/w) to about 0.5% (w/w) of a chelating agent. In certain embodiments, the formulation comprises about 0.01% (w/w) to about 0.05% (w/w) of a chelating agent. In certain embodiments, the formulation comprises about 0.025% (w/w) of a chelating agent. 
     Exemplary chelating agents include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), citric acid, sorbitol, tartaric acid, phosphoric acid, salts of the foregoing, and the like. In certain embodiments, the chelating agent is an aliphatic amine compound containing at least two carboxylic acid groups. In certain embodiments, the chelating agent is ethylenediaminetetraacetic acid or a salt thereof. 
     In certain embodiments, the chelating agent is a metal ion chelating agent. 
     In certain embodiments, the combination of an antioxidant and a chelating agent (e.g., ethylenediaminetetraacetic acid or salt thereof) can increase the stability of an aqueous capsaicin formulation. 
     Buffer 
     The formulation may optionally further comprise a buffer. The buffer helps reduce changes in pH of the formulation over time and may provide improved drug stability. Exemplary buffers include, but are not limited to, sodium bicarbonate, sodium citrate, citric acid, sodium phosphate, pharmaceutically acceptable salts thereof, and combinations thereof. In certain embodiments, the buffer is an acetate salt, phosphate salt, citrate salt; corresponding acids of the foregoing; and combinations or mixtures thereof. 
     Accordingly, in certain embodiments, the formulation further comprises a buffer. In certain embodiments, the buffer comprises a carboxylic acid compound having a molecular weight less than 500 g/mol, a salt thereof, or a mixture thereof. In certain embodiments, the buffer comprises a C 1 -C 6  alkanoic acid, a salt thereof, or a mixture thereof. In certain embodiments, the buffer comprises acetic acid, a salt of acetic acid, or a mixture thereof. In certain embodiments, the buffer is a mixture of alkali metal acetate and acetic acid. In certain embodiments, the buffer is a mixture of sodium acetate and acetic acid. 
     In certain embodiments, the formulation comprises about 0.1% (w/w) to about 1.0% (w/w) of a buffer. In certain embodiments, the formulation comprises about 0.5% (w/w) to about 0.8% (w/w) of a buffer. In certain embodiments, the formulation comprises about 0.7% (w/w) of a buffer. The amount of buffer may be alternatively characterized according to the molarity of the buffer in the formulation. Accordingly, in certain embodiments, the formulation comprises about 10 mM to about 100 mM of a buffer. In certain embodiments, the formulation comprises about 25 mM to about 75 mM of a buffer. In certain embodiments, the formulation comprises about 50 mM of a buffer (which preferably is a mixture of an alkali metal acetate and acetic acid, such as a mixture of sodium acetate and acetic acid). 
     Osmolality 
     The formulation may be further characterized according to the osmolality of the formulation. Formulations having an osmolality at or near the osmolality of a typical bodily fluid are referred to as isotonic. Formulations having an osmolality greater than the osmolality of a typical bodily fluid are referred to as hypertonic. Formulations having an osmolality less than the osmolality of a typical bodily fluid are referred to as hypotonic. 
     The osmolality of the formulation may be optionally adjusted by including a tonicity modifier. Accordingly, in certain embodiments, the formulation further comprises a tonicity modifier. In certain embodiments, the formulation comprises about 0.01% (w/w) to about 5% (w/w) of a tonicity modifier. In certain embodiments, the formulation comprises about 0.1% (w/w) to about 2% (w/w) of a tonicity modifier. In certain embodiments, the formulation comprises about 0.3% (w/w) to about 0.9% (w/w) of a tonicity modifier. In certain embodiments, the formulation comprises about 0.6% (w/w) of a tonicity modifier (which preferably is an alkali metal halide, such as sodium chloride). 
     In certain embodiments, the tonicity modifier is an alkali metal salt. In certain embodiments, the tonicity modifier is sodium chloride. In certain embodiments, the tonicity modifier is a monosaccharide. In certain embodiments, the tonicity modifier is dextrose. 
     Formulations may be characterized according to an osmolality threshold or range. For example, in certain embodiments, the formulation may have an osmolality of at least 200 mOsm/kg, 220 mOsm/kg, 240 mOsm/kg, 260 mOsm/kg, 280 mOsm/kg, 300 mOsm/kg, 325 mOsm/kg, 350 mOsm/kg, 375 mOsm/kg, 400 mOsm/kg, 425 mOsm/kg, 450 mOsm/kg, 500 mOsm/kg, 600 mOsm/kg, 700 mOsm/kg, 800 mOsm/kg, 900 mOsm/kg, or 1000 mOsm/kg. In certain embodiments, the formulation has an osmolality of at least 240 mOsm/kg. In certain embodiments, the formulation has an osmolality of at least 270 mOsm/kg. 
     In certain embodiments, the formulation has an osmolality in the range of from about 200 mOsm/kg to about 400 mOsm/kg, from about 240 mOsm/kg to about 350 mOsm/kg, from about 240 mOsm/kg to about 340 mOsm/kg, from about 270 mOsm/kg to about 340 mOsm/kg, from about 270 mOsm/kg to about 330 mOsm/kg, from about 270 mOsm/kg to about 310 mOsm/kg, from about 290 mOsm/kg to about 330 mOsm/kg, from about 280 mOsm/kg to about 300 mOsm/kg, or from about 300 mOsm/kg to about 320 mOsm/kg. In certain embodiments, the formulation has an osmolality in the range of from about 240 mOsm/kg to about 340 mOsm/kg. In certain other embodiments, the formulation has an osmolality in the range from about 270 mOsm/kg to about 330 mOsm/kg. 
     In certain embodiments, the formulation has osmolality of about 200 mOsm/kg, about 220 mOsm/kg, about 240 mOsm/kg, about 250 mOsm/kg, about 260 mOsm/kg, about 270 mOsm/kg, about 280 mOsm/kg, about 290 mOsm/kg, about 300 mOsm/kg, about 310 mOsm/kg, about 320 mOsm/kg, about 330 mOsm/kg, about 340 mOsm/kg, about 350 mOsm/kg, about 360 mOsm/kg, about 370 mOsm/kg, or about 380 mOsm/kg. In a preferred embodiment, the formulation has osmolality of about 290 mOsm/kg. In another preferred embodiment, the formulation has osmolality of about 310 mOsm/kg. 
     Amount of Water 
     The formulation may be further characterized according to the amount of water in the formulation. For example, in certain embodiments, the formulation comprises at least 95% (w/w) water. In certain embodiments, the formulation comprises at least 97% (w/w) water. In certain embodiments, the formulation comprises from about 95% (w/w) to about 99% (w/w) water. In certain embodiments, the formulation comprises from about 97% (w/w) to about 98% (w/w) water. In certain embodiments, the formulation comprises from about 93% (w/w) to about 96% (w/w) water. 
     pH of the Formulation 
     The formulation may be further characterized according to the pH of the formulation. For example, in certain embodiments, the formulation has a pH in the range of about 4 to about 7. In certain embodiments, the formulation has a pH in the range of about 5 to about 6. In certain embodiments, the formulation has a pH in the range of about 5.0 to about 5.2, about 5.2 to about 5.4, about 5.4 to about 5.6, or about 5.6 to about 5.8. In certain embodiments, the formulation has a pH of about 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, or 5.9. In certain embodiments, the formulation has a pH of about 5.5. 
     Vanilloid Receptor Agonist 
     For a formulation containing a vanilloid receptor agonist, the formulation may be further characterized according to the amount and identity of the vanilloid receptor agonist. For example, in certain embodiments, the formulation comprises from about 0.001% (w/w) to about 5% (w/w), from about 0.001% (w/w) to about 1% (w/w), or from about 0.01% (w/w) to about 0.1% (w/w) of vanilloid receptor agonist. Exemplary vanilloid receptor agonists include, for example, capsaicin, resiniferatoxin, N-vanillylnonanamides, N-vanillylsulfonamides, N-vanillylureas, N-vanillylcarbamates, N-[(substituted phenyl)methyl]alkylamides, methylene substituted N-[(substituted phenyl)methyl]alkanamides, N-[(substituted phenyl)methyl]-cis-monosaturated alkenamides, N-[(substituted phenyl)methyl]diunsaturated amides, 3-hydroxyacetanilide, hydroxyphenylacetamides, pseudocapsaicin, dihydrocapsaicin, nordihydrocapsaicin anandamide, piperine, zingerone, warburganal, polygodial, aframodial, cinnamodial, cinnamosmolide, cinnamolide, isovelleral, scalaradial, ancistrodial, beta-acaridial, merulidial, and scutigeral. 
     Capsaicin 
     Capsaicin has the chemical name N-[(4-hydroxy-3-methoxyphenyl)methyl]-8-methylnon-6-enamide, and due to the presence of a carbon-carbon double bond can exist as a mixture of cis and trans isomers. The formulations may be characterized according to the isomeric purity of the capsaicin administered to the patient. For example, in certain embodiments, the capsaicin is a mixture of cis-capsaicin and trans-capsaicin that contains at least 95% by weight trans-capsaicin. In certain embodiments, the capsaicin is a mixture of cis-capsaicin and trans-capsaicin that contains at least 97% by weight trans-capsaicin. In certain embodiments, the capsaicin is a mixture of cis-capsaicin and trans-capsaicin that contains at least 98% by weight trans-capsaicin. In certain embodiments, the capsaicin is a mixture of cis-capsaicin and trans-capsaicin that contains at least 99% by weight trans-capsaicin. In certain other embodiments, the capsaicin is a mixture of cis-capsaicin and trans-capsaicin that contains at least 95% by weight cis-capsaicin. Accordingly, formulations described herein containing capsaicin can be characterized according to the isomeric purity of the capsaicin. 
     The isomeric purity of capsaicin may also be expressed according to the molar ratio of trans vs. cis isomer. Accordingly, in certain embodiments, the capsaicin is present as a mixture of trans and cis isomers, wherein the ratio of trans:cis isomers is at least 10:1. In certain embodiments, the ratio of trans:cis isomers is at least 15:1. In certain embodiments, the capsaicin consists essentially of the trans isomer. 
     The formulation may be further characterized according to the amount of capsaicin in the formulation. For example, in certain embodiments, the formulation comprises from about 0.03% (w/w) to about 0.15% (w/w) of capsaicin. In certain embodiments, the formulation comprises from about 0.03% (w/w) to about 0.07% (w/w) of capsaicin. In certain embodiments, the formulation comprises from about 0.01% (w/w) to about 0.03% (w/w) of capsaicin, 0.03% (w/w) to about 0.05% (w/w) of capsaicin, 0.05% (w/w) to about 0.07% (w/w) of capsaicin, 0.07% (w/w) to about 0.09% (w/w) of capsaicin, 0.09% (w/w) to about 0.11% (w/w) of capsaicin, or 0.11% (w/w) to about 0.13% (w/w) of capsaicin. In certain embodiments, the formulation comprises from about 0.04% (w/w) to about 0.06% (w/w) of capsaicin. In certain embodiments, the formulation comprises about 0.05% (w/w) of capsaicin. In certain embodiments, the formulation comprises from about 0.08% (w/w) to about 0.12% (w/w) of capsaicin. In certain embodiments, the formulation comprises from about 0.12% (w/w) to about 0.15% (w/w) of capsaicin, from about 0.15% (w/w) to about 0.18% (w/w) of capsaicin, from about 0.18% (w/w) to about 0.21% (w/w) of capsaicin, from about 0.21% (w/w) to about 0.25% (w/w) of capsaicin, or from about 0.25% (w/w) to about 0.3% (w/w) of capsaicin. In certain embodiments, the formulation comprises about 0.1% (w/w) of capsaicin. 
     Additional Pain-Relief Agent 
     The formulation may optionally contain a further pain-relief agent. For example, in certain embodiments, the formulation may further comprise a caine alkaloid. Exemplary caine alkaloids include lidocaine, dibucaine, bupivacaine, ropivacaine, etidocaine, tetracaine, procaine, chlorocaine, prilocaine, mepivacaine, xylocaine, 2-chloroprocaine, and pharmaceutically acceptable salts thereof. In certain embodiments, the formulation further comprises lidocaine, such as where the lidocaine is present in an amount of about 0.5% (w/w), 1.0% (w/w), 2.0% (w/w), 3.0% (w/w) or 4.0% (w/w) of the formulation, or in an amount ranging from about 0.5% (w/w) to about 2.0% (w/w), or about 2.0% (w/w) to about 4.0% (w/w) of the formulation. 
     Sterility of the Formulation 
     The formulation may be further characterized according to the sterility of the formulation and procedures used to sterilize the formulation. Accordingly, in certain embodiments, the formulation has a sterility assurance level of from about 10 −1  to 10 −3 , about 10 −3  to about 10 −4 , about 10 −4  to about 10 −5 , about 10 −5  to about 10 −6 , or about 10 −6  to about 10 −7 , or a sterility assurance level that is more sterile than 10 −7 . In certain embodiments, the sterility assurance level that is more sterile than about 10 −3 , about 10 −4 , about 10 −5 , or about 10 −6 . 
     One method for improving the sterility of the formulation is to pass the formulation through a sterile filter. Such filter may be a 0.2 micron sterilizing filter. 
     Alternatively, the formulation may be subjected to sterilization by heating to above ambient temperature. Accordingly, in certain embodiments, the formulation may be characterized by the feature that the formulation has been subjected to sterilization by heating to above ambient temperature. In certain embodiments, the formulation may be characterized by the feature that the formulation has been subjected to sterilization by heating to a temperature in the range of from about 100° C. to about 135° C. In certain embodiments, the formulation has been subjected to sterilization by heating to a temperature in the range of from about 120° C. to about 125° C. In certain embodiments, the formulation has been subjected to sterilization conditions that achieve a F 0 -value in the range of from about 6 to about 10. In certain embodiments, the formulation has been subjected to sterilization conditions that achieve a F 0 -value of about 8. In certain embodiments, the formulation has been subjected to sterilization conditions that achieve a F 0 -value in the range of from about 20 to about 30. In certain embodiments, the formulation has been subjected to sterilization conditions that achieve a F 0 -value of about 25. 
     Exemplary Formulations 
     In certain embodiments, the formulation is one of the formulations in Table 1 below. 
     
       
         
           
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                 No. 
                 Formulation 
               
               
                   
               
             
            
               
                 1 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                 a. about 0.03% (w/w) to about 0.3% (w/w) of capsaicin; 
               
               
                   
                 b. about 0.1% (w/w) to about 3% (w/w) of a solubilizing agent,  
               
               
                   
                 wherein the solubilizing agent comprises (i) a polyethylene  
               
               
                   
                 glycol ester of a (C 15 —C 25 ) hydroxyalkanoic acid, (ii) a  
               
               
                   
                 polyethylene glycol ester of a (C 15 —C 25 ) hydroxyalkenoic  
               
               
                   
                 acid, or (iii) a polyethylene glycol ester of a (C 15 —C 25 )  
               
               
                   
                 alkanoic acid substituted by a —OC(O)(C 14 —C 24 )  
               
               
                   
                 hydroxyalkyl group; 
               
               
                   
                 c. about 0.001% (w/w) to about 2% (w/w) of an antioxidant; and 
               
               
                   
                 d. at least 92% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 3 to about 8. 
               
               
                 2 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                 a. about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; 
               
               
                   
                 b. about 0.7% (w/w) to about 1.3% (w/w) of a solubilizing agent,  
               
               
                   
                 wherein the solubilizing agent comprises (i) a polyethylene  
               
               
                   
                 glycol ester of a (C 15 —C 25 ) hydroxyalkanoic acid, or (ii) a  
               
               
                   
                 polyethylene glycol ester of a (C 15 —C 25 ) hydroxyalkenoic acid; 
               
               
                   
                 c. about 0.001% (w/w) to about 0.1% (w/w) of an antioxidant; and 
               
               
                   
                 d. at least 92% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 4 to about 7. 
               
               
                 3 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                 a. about 0.04% (w/w) to about 0.06% (w/w) of trans-capsaicin; 
               
               
                   
                 b. about 0.7% (w/w) to about 1.3% (w/w) of a solubilizing agent,  
               
               
                   
                 wherein the solubilizing agent comprises (a) from about 60%  
               
               
                   
                 (w/w) to about 80% (w/w) of a mixture of  
               
               
                   
                 (C 17 )hydroxyalkyl—CO 2 —(polyethylene glycolyl)—H and  
               
               
                   
                 (C 17 )hydroxyalkyl—CO 2 —(C 17 )alkylene—CO 2 —(polyethylene  
               
               
                   
                 glycolyl)—H, and (b) from about 20% (w/w) to about 40% (w/w)  
               
               
                   
                 polyethylene glycol; 
               
               
                   
                 c. about 0.001% (w/w) to about 0.1% (w/w) of an antioxidant; and 
               
               
                   
                 d. at least 95% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 4 to about 7. 
               
               
                 4 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                 a. about 0.08% (w/w) to about 0.12% (w/w) of capsaicin; 
               
               
                   
                 b. about 1.8% (w/w) to about 2.2% (w/w) of a solubilizing agent,  
               
               
                   
                 wherein the solubilizing agent comprises (i) a polyethylene glycol  
               
               
                   
                 ester of a (C 15 —C 25 ) hydroxyalkanoic acid, or (ii) a polyethylene  
               
               
                   
                 glycol ester of a (C 15 —C 25 ) hydroxyalkenoic acid; 
               
               
                   
                 c. about 0.001% (w/w) to about 0.1% (w/w) of an antioxidant; and 
               
               
                   
                 d. at least 93% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 4 to about 7. 
               
               
                 5 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                 a. about 0.08% (w/w) to about 0.12% (w/w) of capsaicin; 
               
               
                   
                 b. about 1.8% (w/w) to about 2.2% (w/w) of a solubilizing agent,  
               
               
                   
                 wherein the solubilizing agent comprises (a) from about 60%  
               
               
                   
                 (w/w) to about 80% (w/w) of a mixture of  
               
               
                   
                 (C 17 )hydroxyalkyl—CO 2 —(polyethylene glycolyl)—H  
               
               
                   
                 and (C 17 )hydroxyalkyl—CO 2 —(C 17 )alkylene—CO 2 — 
               
               
                   
                 (polyethylene glycolyl)—H, and (b) from about 20% (w/w) to  
               
               
                   
                 about 40% (w/w) polyethylene glycol; 
               
               
                   
                 c. about 0.001% (w/w) to about 0.1% (w/w) of an antioxidant; and 
               
               
                   
                 d. at least 93% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 4 to about 7. 
               
               
                   
               
            
           
         
       
     
     Exemplary more specific formulations are provided in Tables 2 and 3 below. 
     
       
         
           
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                 No. 
                 Formulation 
               
               
                   
               
             
            
               
                 1 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; 
               
               
                   
                  b. about 0.5% (w/w) to about 1.5% (w/w) of a solubilizing agent, wherein 
               
               
                   
                   the solubilizing agent comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.005% (w/w) to about 0.015% (w/w) of an antioxidant; 
               
               
                   
                  d. about 0.3% (w/w) to about 1% (w/w) of an alkali metal acetate; 
               
               
                   
                  e. about 0.01% (w/w) to about 0.05% (w/w) of a chelating agent; 
               
               
                   
                  f. about 0.3% (w/w) to about 0.9% (w/w) of a tonicity modifier; 
               
               
                   
                  g. at least 95% (w/w) water; and 
               
               
                   
                   having a pH in the range of about 5 to about 6. 
               
               
                 2 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; 
               
               
                   
                  b. about 0.8% (w/w) to about 1.2% (w/w) of a solubilizing agent, wherein 
               
               
                   
                   the solubilizing agent comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.3% (w/w) to about 1% (w/w) of sodium acetate; 
               
               
                   
                  e. about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic 
               
               
                   
                   acid or a salt thereof; 
               
               
                   
                  f. about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 95% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 5 to about 6. 
               
               
                 3 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. about 1% (w/w) of a solubilizing agent, wherein the solubilizing 
               
               
                   
                   agent comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.5% (w/w) to about 0.8% (w/w) of sodium acetate; 
               
               
                   
                  e. about 0.01% (w/w) to about 0.05% (w/w) of 
               
               
                   
                   ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                  f. about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 95% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 5 to about 6. 
               
               
                 4 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.08% (w/w) to about 0.12% (w/w) of capsaicin; 
               
               
                   
                  b. about 1.5% (w/w) to about 2.5% (w/w) of a solubilizing agent, wherein 
               
               
                   
                   the solubilizing agent comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   polyethylene glycol; 
               
               
                   
                  c. about 0.005% (w/w) to about 0.015% (w/w) of an antioxidant; 
               
               
                   
                  d. about 0.1% (w/w) to about 1% (w/w) of an alkali metal carboxylate 
               
               
                   
                   compound; 
               
               
                   
                  e. about 0.01% (w/w) to about 0.5% (w/w) of a chelating agent; 
               
               
                   
                  f. about 2% (w/w) to about 4% (w/w) of a tonicity modifier; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                   having a pH in the range of about 5 to about 6. 
               
               
                 5 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.08% (w/w) to about 0.12% (w/w) of capsaicin; 
               
               
                   
                  b. about 1.8% (w/w) to about 2.2% (w/w) of a solubilizing agent, wherein 
               
               
                   
                   the solubilizing agent comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.005% (w/w) to about 0.015% (w/w) of an antioxidant; 
               
               
                   
                  d. about 0.1% (w/w) to about 1% (w/w) of an alkali metal carboxylate 
               
               
                   
                   compound; 
               
               
                   
                  e. about 0.01% (w/w) to about 0.5% (w/w) of a chelating agent; 
               
               
                   
                  f. about 2% (w/w) to about 4% (w/w) of a tonicity modifier; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 5 to about 6. 
               
               
                 6 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.1% (w/w) of capsaicin; 
               
               
                   
                  b. about 2% (w/w) of a solubilizing agent, wherein the solubilizing agent 
               
               
                   
                   comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   polyethylene glycol; 
               
               
                   
                  c. about 0.005% (w/w) to about 0.015% (w/w) of an antioxidant; 
               
               
                   
                  d. about 0.1% (w/w) to about 1% (w/w) of an alkali metal carboxylate 
               
               
                   
                   compound; 
               
               
                   
                  e. about 0.01% (w/w) to about 0.5% (w/w) of a chelating agent; 
               
               
                   
                  f. about 2.5% (w/w) to about 3.5% (w/w) of a tonicity modifier; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                 having a pH in the range of about 5 to about 6. 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                 TABLE 3 
               
               
                   
               
               
                 No. 
                 Formulation 
               
               
                   
               
             
            
               
                 1 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.1% (w/w) of capsaicin; 
               
               
                   
                  b. about 2% (w/w) of a solubilizing agent, wherein the solubilizing agent 
               
               
                   
                   comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.01% (w/w) of an antioxidant; 
               
               
                   
                  d. about 0.1% (w/w) to about 1% (w/w) of an alkali metal citrate salt; 
               
               
                   
                  e. about 0.1% (w/w) of a chelating agent; 
               
               
                   
                  f. about 3% (w/w) of a tonicity modifier; and 
               
               
                   
                  g. at least 93% (w/w) water. 
               
               
                 2  
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.1% (w/w) of capsaicin; 
               
               
                   
                  b. about 2% (w/w) of a solubilizing agent, wherein the solubilizing agent 
               
               
                   
                   comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.01% (w/w) of dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.1% (w/w) to about 1% (w/w) of a disodium citrate salt; 
               
               
                   
                  e. about 0.1% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                  f. about 3% (w/w) of dextrose; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                   having a pH in the range of about 5 to about 6. 
               
               
                 3 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.1% (w/w) of trans-capsaicin; 
               
               
                   
                  b. about 2% (w/w) of a solubilizing agent, wherein the solubilizing agent 
               
               
                   
                   that comprises 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; 
               
               
                   
                  c. about 0.01% (w/w) of dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.1% (w/w) to about 1% (w/w) of a disodium citrate salt; 
               
               
                   
                  e. about 0.1% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                  f. about 3% (w/w) of dextrose; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                   having a pH in the range of about 5 to about 6. 
               
               
                   
               
            
           
         
       
     
     In yet other embodiments, the aqueous, capsaicin injectable formulation comprises (a) about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; (b) about 0.5% (w/w) to about 1.5% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises 
     
       
         
         
             
             
         
       
     
     and polyethylene glycol; (c) about 0.005% (w/w) to about 0.015% (w/w) of an antioxidant; (d) about 0.2% (w/w) to about 1% (w/w) of an alkali metal acetate; (e) about 0.01% (w/w) to about 0.05% (w/w) of a chelating agent; (f) about 0.3% (w/w) to about 0.9% (w/w) of a tonicity modifier; and (g) at least 96% (w/w) water; and having a pH in the range of about 5 to about 6. 
     In other embodiments, the aqueous, capsaicin injectable formulation comprises (a) about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; (b) about 0.8% (w/w) to about 1.2% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises 
     
       
         
         
             
             
         
       
     
     and polyethylene glycol; (c) about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene; (d) about 0.2% (w/w) to about 1% (w/w) of sodium acetate; (e) about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; (f) about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; (g) at least 96% (w/w) water; and has a pH in the range of about 5 to about 6. 
     In other embodiments, the aqueous, capsaicin injectable formulation comprises
         a. about 0.04% (w/w) to about 0.06% (w/w) of capsaicin;   b. about 0.8% (w/w) to about 1.2% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises (a) about 70% (w/w) of a mixture of       

     
       
         
         
             
             
         
       
         
         
           
              and (b) about 30% (w/w) polyethylene glycol; 
             c. about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene; 
             d. about 0.2% (w/w) to about 1% (w/w) of sodium acetate; 
             e. about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
             f. about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; 
             g. at least 96% (w/w) water; and 
           
         
       
    
     having a pH in the range of about 5 to about 6. 
     In other embodiments, the aqueous, capsaicin injectable formulation comprises
         a. about 0.04% (w/w) to about 0.06% (w/w) of capsaicin;   b. about 0.8% (w/w) to about 1.2% (w/w) of a solubilizing agent, wherein the solubilizing agent is a mixture of (a) about 70% (w/w) of a mixture of       

     
       
         
         
             
             
         
       
         
         
           
              and (b) about 30% (w/w) polyethylene glycol; 
             c. about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene; 
             d. about 0.2% (w/w) to about 1% (w/w) of sodium acetate; 
             e. about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
             f. about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; 
             g. at least 96% (w/w) water; and 
           
         
       
    
     having a pH in the range of about 5 to about 6. 
     In other embodiments, the aqueous, capsaicin injectable formulation comprises
         a. about 0.05% (w/w) of capsaicin;   b. about 1% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises       

     
       
         
         
             
             
         
       
     
     and polyethylene glycol;
         c. about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene;   d. about 0.2% (w/w) to about 1% (w/w) of sodium acetate;   e. about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof;   f. about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride;   g. at least 96% (w/w) water; and       

     having a pH of about 5.5. 
     In other embodiments, the aqueous, capsaicin injectable formulation comprises
         a. about 0.05% (w/w) of capsaicin;   b. about 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is a mixture of       

     
       
         
         
             
             
         
       
     
     and polyethylene glycol;
         c. about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene;   d. about 0.2% (w/w) to about 1% (w/w) of sodium acetate;   e. about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof;   f. about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride;   g. at least 96% (w/w) water; and       

     having a pH of about 5.5. 
     Each of the foregoing formulations may be further characterized according to the weight-average molecular weight of the polyethylene glycol component(s). Accordingly, in certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 200 g/mol to about 1500 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 200 g/mol to about 1000 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 300 g/mol to about 900 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 500 g/mol to about 800 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 600 g/mol to about 700 g/mol. In certain embodiments, the polyethylene glycol has a weight-average molecular weight in the range of about 100 g/mol to about 300 g/mol, about 300 g/mol to about 500 g/mol, about 500 g/mol to about 1000 g/mol, about 1000 g/mol to about 1500 g/mol, about 1500 g/mol to about 2000 g/mol, or about 2000 g/mol to about 2500 g/mol. 
     Additionally, each of the foregoing formulations may be further characterized according to the weight-average molecular weight of any polyethylene glycolyl component. For example, in certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 100 g/mol to about 3000 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 200 g/mol to about 1500 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 200 g/mol to about 1000 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 300 g/mol to about 900 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 500 g/mol to about 800 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 600 g/mol to about 750 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 600 g/mol to about 700 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol. In certain embodiments, the polyethylene glycolyl has a weight-average molecular weight in the range of about 100 g/mol to about 300 g/mol, about 300 g/mol to about 500 g/mol, about 500 g/mol to about 1000 g/mol, about 1000 g/mol to about 1500 g/mol, about 1500 g/mol to about 2000 g/mol, or about 2000 g/mol to about 2500 g/mol. 
     In yet other embodiments, the aqueous, capsaicin injectable formulation comprises (a) about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; (b) about 0.5% (w/w) to about 1.5% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises macrogol 15 hydroxystearate; (c) about 0.005% (w/w) to about 0.015% (w/w) of an antioxidant; (d) about 0.2% (w/w) to about 1% (w/w) of an alkali metal acetate; (e) about 0.01% (w/w) to about 0.05% (w/w) of a chelating agent; (f) about 0.3% (w/w) to about 0.9% (w/w) of a tonicity modifier; and (g) at least 96% (w/w) water; and having a pH in the range of about 5 to about 6. In other embodiments, the aqueous, capsaicin injectable formulation comprises (a) about 0.04% (w/w) to about 0.06% (w/w) of capsaicin; (b) about 0.8% (w/w) to about 1.2% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises macrogol 15 hydroxystearate; (c) about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene; (d) about 0.2% (w/w) to about 1% (w/w) of sodium acetate; (e) about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; (f) about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; (g) at least 96% (w/w) water; and has a pH in the range of about 5 to about 6; wherein the formulation has been subjected to sterilization procedures (e.g., sterilization by heating to above ambient temperature (e.g., autoclave sterilization)). In other embodiments, the aqueous, capsaicin injectable formulation comprises (a) about 0.05% (w/w) of capsaicin; (b) about 1% (w/w) of a solubilizing agent, wherein the solubilizing agent comprises macrogol 15 hydroxystearate; (c) about 0.005% (w/w) to about 0.015% (w/w) of dibutylhydroxytoluene; (d) about 0.2% (w/w) to about 1% (w/w) of sodium acetate; (e) about 0.01% (w/w) to about 0.05% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; (f) about 0.3% (w/w) to about 0.9% (w/w) of sodium chloride; (g) at least 96% (w/w) water; and having a pH of about 5.5; wherein optionally the formulation has been subjected to sterilization procedures (e.g., sterilization by heating to above ambient temperature (e.g., autoclave sterilization)). 
     Exemplary more specific formulations are provided in Tables 4 and 5 below. 
     
       
         
           
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                 No. 
                 Formulation 
               
               
                   
               
             
            
               
                 1 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. about 1% (w/w) of a solubilizing agent, wherein the solubilizing 
               
               
                   
                   agent is a mixture of 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. about 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.68% (w/w) of sodium acetate or a mixture of sodium 
               
               
                   
                   acetate and acetic acid; 
               
               
                   
                  e. about 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt 
               
               
                   
                   thereof; 
               
               
                   
                  f. about 0.6% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 97% (w/w) water; and 
               
               
                   
                 having a pH of about 5.5. 
               
               
                 2 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   
                   a mixture of 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. 0.68% (w/w) of sodium acetate or a mixture of sodium acetate and 
               
               
                   
                   acetic acid; 
               
               
                   
                  e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                  f. 0.6% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 97% (w/w) water; and 
               
               
                   
                 having a pH of 5.5. 
               
               
                 3 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. about 1% (w/w) of a solubilizing agent, wherein the solubilizing 
               
               
                   
                   agent is a mixture of 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. about 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.34% (w/w) of sodium acetate or a mixture of sodium 
               
               
                   
                   acetate and acetic acid; 
               
               
                   
                  e. about 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt 
               
               
                   
                   thereof; 
               
               
                   
                  f. about 0.75% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 97% (w/w) water; and 
               
               
                   
                 having a pH of about 5.5.  
               
               
                 4  
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   
                   a mixture of 
               
               
                   
               
               
                   
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                   
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. 0.34% (w/w) of sodium acetate or a mixture of sodium acetate and 
               
               
                   
                   acetic acid; 
               
               
                   
                  e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                  f. 0.75% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 97% (w/w) water; and 
               
               
                   
                 having a pH of 5.5. 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 No. 
                 Formulation 
               
               
                   
               
             
            
               
                 1 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. about 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. about 1% (w/w) of a solubilizing agent, wherein the solubilizing 
               
               
                   
                   agent is a mixture of 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                                    
 
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. about 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. about 0.22% (w/w) of sodium citrate or a mixture of sodium citrate 
               
               
                   
                   and citric acid; 
               
               
                   
                  e. about 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt 
               
               
                   
                   thereof; 
               
               
                   
                  f. about 0.8% (w/w) of sodium chloride; 
               
               
                   
                  g. at least 97% (w/w) water; and 
               
            
           
           
               
            
               
                 having a pH of about 5.5. 
               
            
           
           
               
               
            
               
                 2 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                  b. 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   
                   a mixture of 
               
               
                   
               
            
           
           
               
               
               
            
               
                   
                                    
 
                   
               
               
                   
               
               
                   
                                    
 
                   
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
                   
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
                   
               
               
                   
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
                   
               
               
                   
                  d. 0.22% (w/w) of sodium citrate or a mixture of sodium citrate and 
                   
               
               
                   
                   citric acid; 
                   
               
               
                   
                  e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
                   
               
               
                   
                  f. 0.8% (w/w) of sodium chloride; 
                   
               
               
                   
                  g. at least 97% (w/w) water; and 
                   
               
               
                   
                 having a pH of 5.5. 
                   
               
               
                 3 
                 An aqueous, capsaicin injectable formulation, comprising: 
                   
               
               
                   
                  a. about 1% (w/w) of trans-capsaicin; 
                   
               
               
                   
                  b. about 2% (w/w) of a solubilizing agent, wherein the solubilizing 
                   
               
               
                   
                   agent is a mixture of 
                   
               
               
                   
               
               
                   
                                    
 
                   
               
               
                   
               
               
                   
                                    
 
                   
               
               
                   
               
            
           
           
               
               
            
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. about 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. about 20 mM of sodium citrate or a mixture of sodium citrate and 
               
               
                   
                   citric acid; 
               
               
                   
                  e. about 0.1% (w/w) of ethylenediaminetetraacetic acid or a salt 
               
               
                   
                   thereof; 
               
               
                   
                  f. about 3.15% (w/w) of dextrose; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                 having a pH of about 5 to about 6. 
               
               
                 4 
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                   
                  a. 1% (w/w) of trans-capsaicin; 
               
               
                   
                  b. 2% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   
                   a mixture of 
               
               
                   
               
            
           
           
               
               
               
            
               
                   
                                    
 
                   
               
               
                   
               
            
           
           
               
               
            
               
                   
                 
                   
                     
                     
                         
                         
                     
                   
                 
               
               
                   
               
               
                   
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   
                   weight average molecular weight of about 660 g/mol; 
               
               
                   
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                   
                  d. 20 mM of sodium citrate or a mixture of sodium citrate and citric 
               
               
                   
                   acid; 
               
               
                   
                  e. 0.1% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                  f. 3.15% (w/w) of dextrose; 
               
               
                   
                  g. at least 93% (w/w) water; and 
               
               
                   
                 having a pH of about 5 to about 6. 
               
               
                   
               
            
           
         
       
     
     In certain embodiments, the formulation is one of the formulations described in Tables 1-5 above, wherein the formulation has an osmolality in the range of from about 240 mOsm/kg to about 340 mOsm/kg. In certain embodiments, the formulation is one of the formulations described in Tables 1-5 above, wherein the formulation has an osmolality in the range from about 270 mOsm/kg to about 330 mOsm/kg. 
     Stability of the Aqueous Capsaicin Injectable Formulations 
     A formulation containing capsaicin can be further characterized according to the stability of the formulation upon storage. For example, in certain embodiments, the formulation is characterized by the feature that less than 1% of the capsaicin degrades upon storage at 25° C. for 24 weeks. In certain other embodiments, less than 0.5% of the capsaicin degrades upon storage at 25° C. for 24 weeks. In certain other embodiments, less than 0.1% of the capsaicin degrades upon storage at 25° C. for 24 weeks. In certain other embodiments, less than 1% of the capsaicin degrades upon storage at 40° C. for 24 weeks. In certain other embodiments, less than 0.5% of the capsaicin degrades upon storage at 40° C. for 24 weeks. 
     Amount of Capsaicin-Dimer in an Aqueous Capsaicin Injectable Formulation 
     A formulation containing capsaicin can be further characterized according to the amount of any impurities in the formulation, such as the amount of capsaicin-dimer having the following formula: 
     
       
         
         
             
             
         
       
     
     Accordingly, in certain embodiments, the formulation is characterized by the feature that it contains less than 3% (w/w) of capsaicin-dimer having the following structure: 
     
       
         
         
             
             
         
       
     
     In certain other embodiments, the formulation contains less than 2% (w/w) of the capsaicin-dimer. In certain other embodiments, the formulation contains less than 1% (w/w) of the capsaicin-dimer. In certain other embodiments, the formulation contains less than 0.6% (w/w) of the capsaicin-dimer. 
     In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 3% (w/w) of capsaicin-dimer having the following structure: 
     
       
         
         
             
             
         
       
     
     In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 2% (w/w) of capsaicin-dimer. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 1% (w/w) of the capsaicin-dimer. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.6% (w/w) of the capsaicin-dimer. 
     Amount of Substituted 1,1′-Biphenyl Compound in an Aqueous Capsaicin Injectable Formulation 
     A formulation containing capsaicin can be further characterized according to the amount of substituted 1,1′-biphenyl compound having the following structure: 
     
       
         
         
             
             
         
       
     
     In certain embodiments, the formulation contains less than 2% (w/w) of the substituted 1,1′-biphenyl compound. In certain embodiments, the formulation contains less than 1% (w/w) of the substituted 1,1′-biphenyl compound. 
     In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 3% (w/w) of the aforementioned substituted 1,1′-biphenyl compound. In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 2% (w/w) of the substituted 1,1′-biphenyl compound. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 1% (w/w) of the substituted 1,1′-biphenyl compound. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.6% (w/w) of substituted 1,1′-biphenyl compound. 
     Amount of Substituted 1,1′-Bibenzyl Compound in an Aqueous Capsaicin Injectable Formulation 
     A formulation containing capsaicin can be further characterized according to the amount of substituted 1,1′-bibenzyl compound having the following structure: 
     
       
         
         
             
             
         
       
     
     In certain embodiments, the formulation contains less than 2% (w/w) of the substituted 1,1′-bibenzyl compound. In certain embodiments, the formulation contains less than 1% (w/w) of the substituted 1,1′-bibenzyl compound. In certain embodiments, the formulation contains less than 0.5% (w/w) of the substituted 1,1′-bibenzyl compound. In certain embodiments, the formulation contains less than 0.1% (w/w) of the substituted 1,1′-bibenzyl compound. In certain embodiments, the formulation contains less than 0.05% (w/w) of the substituted 1,1′-bibenzyl compound. 
     In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 2% (w/w) of the aforementioned substituted 1,1′-bibenzyl compound. In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 1% (w/w) of the substituted 1,1′-bibenzyl compound. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.5% (w/w) of the substituted 1,1′-bibenzyl compound. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.1% (w/w) of substituted 1,1′-bibenzyl compound. 
     Amount of Substituted 1,2′-Bibenzyl Compound in an Aqueous Capsaicin Injectable Formulation 
     A formulation containing capsaicin can be further characterized according to the amount of substituted 1,2′-bibenzyl compound having the following structure: 
     
       
         
         
             
             
         
       
     
     In certain embodiments, the formulation contains less than 2% (w/w) of the substituted 1,2′-bibenzyl compound. In certain embodiments, the formulation contains less than 1% (w/w) of the substituted 1,2′-bibenzyl compound. In certain embodiments, the formulation contains less than 0.5% (w/w) of the substituted 1,2′-bibenzyl compound. In certain embodiments, the formulation contains less than 0.1% (w/w) of the substituted 1,2′-bibenzyl compound. In certain embodiments, the formulation contains less than 0.05% (w/w) of the substituted 1,1′-bibenzyl compound. 
     In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 2% (w/w) of the aforementioned substituted 1,2′-bibenzyl compound. In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 1% (w/w) of the substituted 1,2′-bibenzyl compound. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.5% (w/w) of the substituted 1,2′-bibenzyl compound. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.1% (w/w) of substituted 1,2′-bibenzyl compound. 
     Amount of 5-Oxo-Capsaicin in an Aqueous Capsaicin Injectable Formulation 
     A formulation containing capsaicin can be further characterized according to the amount of 5-oxo-capsaicin having the following structure: 
     
       
         
         
             
             
         
       
     
     In certain embodiments, the formulation contains less than 2% (w/w) of 5-oxo-capsaicin. In certain embodiments, the formulation contains less than 1% (w/w) of 5-oxo-capsaicin. In certain embodiments, the formulation contains less than 0.5% (w/w) of 5-oxo-capsaicin. In certain embodiments, the formulation contains less than 0.1% (w/w) of 5-oxo-capsaicin. In certain embodiments, the formulation contains less than 0.05% (w/w) of 5-oxo-capsaicin. 
     In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 2% (w/w) of 5-oxo-capsaicin. In certain other embodiments, upon storage at 25° C. for 12 weeks, the formulation contains less than 1% (w/w) of 5-oxo-capsaicin. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.5% (w/w) of 5-oxo-capsaicin. In certain other embodiments, upon storage at 25° C. for 24 weeks, the formulation contains less than 0.1% (w/w) of 5-oxo-capsaicin. 
     Amount of Particulate Matter in an Aqueous Capsaicin Injectable Formulation 
     Formulations herein can be further characterized according to the amount of particulate matter present in the formulation. Accordingly, in certain embodiments, a 2 mL aliquot of the formulation contains less than 6000 particles having an average diameter of ≥10 μm. In certain embodiments, a 2 mL aliquot of the formulation contains less than 3000, 2000, 1000, 750, 500, 400, 300, 200, or 100 particles having an average diameter of ≥10 μm. In certain embodiments, a 2 mL aliquot of the formulation contains less than 1500 particles having an average diameter of ≥10 μm. In certain embodiments, a 2 mL aliquot of the formulation contains less than 1000 particles having an average diameter of ≥10 μm. 
     Further, in certain embodiments, a 2 mL aliquot of the formulation contains less than 1000 particles having an average diameter of ≥25 μm. In certain embodiments, a 2 mL aliquot of the formulation contains less than 750, 700, 600, 500, 400, 300, 200, 100, 75, 50, 40, 30, 25, 20, 15, or 10 particles having an average diameter of ≥25 μm. In certain embodiments, a 2 mL aliquot of the formulation contains less than 600 particles having an average diameter of ≥25 μm. In certain embodiments, a 2 mL aliquot of the formulation contains less than 15 particles having an average diameter of ≥25 μm. 
     Further, in certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 6000 particles having an average diameter of ≥10 μm. In certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 3000, 2000, 1000, 750, 500, 400, 300, 200, or 100 particles having an average diameter of ≥10 μm. In certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 1500 particles having an average diameter of ≥10 μm. In certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 1000 particles having an average diameter of ≥10 μm. 
     Further, in certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 1000 particles having an average diameter of ≥25 μm. In certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 750, 700, 600, 500, 400, 300, 200, 100, 75, 50, 40, 30, 25, 20, 15, or 10 particles having an average diameter of ≥25 μm. In certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 600 particles having an average diameter of ≥25 μm. In certain embodiments, a 2 mL aliquot of the formulation that has been stored at 25° C. and 60% Relative Humidity for a duration of 3 months contains less than 15 particles having an average diameter of ≥25 μm. 
     Amount of Optional Other Components in the Injectable Formulations 
     Formulations herein can be further characterized according to the amount of optional other components. For example, in certain embodiments, the formulation contains less than 0.1% (w/w) of any polysorbate (e.g., polysorable 20 or polysorbate 80). In certain embodiments, the formulation does not contain any polysorbate. In certain embodiments, the formulation contains less than 0.1% (w/w) of any polysorbate, cyclodextrin, or alcohol. In certain embodiments, the formulation does not contain any polysorbate, cyclodextrin, or alcohol. 
     In yet other embodiments, other than said solubilizing agent, the formulation contains less than 0.1% (w/w) of any polymer, oligomer-containing agent, or agent that improves the solubility of capsaicin. In yet other embodiments, other than said solubilizing agent, the formulation does not contain any polymer, oligomer-containing agent, or agent that improves the solubility of capsaicin. In yet other embodiments, the formulation contains less than 0.1% (w/w) of any cyclodextrin, cellulose, alcohol (e.g., menthol), or hyaluronic acid. In yet other embodiments, the formulation does not contain any cyclodextrin, cellulose, alcohol (e.g., menthol), or hyaluronic acid. 
     In certain embodiments, the formulation contains less than 0.1% (w/w) of any phospholipid, polysaccharide, protein polymer, cellulose, sorbitan ester, or histidine. In certain embodiments, the formulation does not contain of any phospholipid, polysaccharide, protein polymer, cellulose, sorbitan ester, or histidine. In certain embodiments, the formulation contains less than 0.1% (w/w) of any polyvinylpyrrolidone polymer. In certain embodiments, the formulation does not contain any polyvinylpyrrolidone polymer. 
     In certain embodiments, the formulation contains less than 0.5% (w/w) of any polyalkylene glycol (e.g., polyethylene glycol) polymer. In certain embodiments, the formulation contains less than 0.3% (w/w), 0.25% (w/w), 0.2% (w/w), 0.15% (w/w), 0.1% (w/w), 0.05% (w/w) 0.01% (w/w) of any polyalkylene glycol (e.g., polyethylene glycol) polymer. 
     In certain embodiments, the formulation contains less than 0.5% (w/w) of any surfactant. In certain embodiments, the formulation contains less than 0.3% (w/w), 0.25% (w/w), 0.2% (w/w), 0.15% (w/w), 0.1% (w/w), 0.05% (w/w) 0.01% (w/w) of any surfactant. In certain embodiments, but for any component of the formulation named in the description of the formulation that would qualify as a surfactant, the formulation does not contain any other agent that is a surfactant. 
     III. Unit Dosage Forms 
     The invention provides a unit dosage form comprising a formulation described herein, such as in any one of Tables 1-5. The unit dosage form can be characterized by, for example, the volume of the unit dosage form, such as where the unit dosage form has a volume in the range of about 0.5 mL to about 3 mL. In certain embodiments, the unit dosage form has a volume in the range of about 1.8 mL to about 2.2 mL. In certain other embodiments, the unit dosage form has a volume of about 2 mL. 
     In certain embodiments, the unit dosage form is characterized by the feature that the formulation is sealed in a container containing an inert gas (such as nitrogen gas). 
     In certain embodiments, the unit dosage form is characterized by the identity of the container housing the unit dosage form, such as where the unit dosage form is in a syringe. 
     IV. Therapeutic Applications 
     The invention provides a method of treating pain in a patient. The method comprises administering to a patient in need thereof a therapeutically effective amount of a formulation described herein, such as a formulation in any one of Tables 1-5, to a site at or near the location of pain, in order to treat the pain. 
     The invention provides a method of treating pain in a patient, wherein the method comprises administering to a patient in need thereof a therapeutically effective amount of a formulation described herein, such as a formulation in any one of Tables 1-5, in order to treat the pain. 
     Another aspect of the invention provides for the use of a formulation described herein (such as a formulation in any one of Tables 1-5) in the manufacture of a medicament. The medicament may be for treating pain in a patient. 
     Types of Pain 
     Various types of pain are contemplated to be treated using formulations described herein. Exemplary types of pain for treatment include pain due to nerve injury (e.g., a neuroma or a neuroma in continuity), pain due to a tumor (e.g., a tumor in soft tissue), pain associated with a painful trigger point, pain due to inflammation, and pain due to injury to tissue. In certain embodiments, the pain is due to a neuropathy, tumor, or inflammation. In other embodiments, the pain is due to inflammation of soft tissue. In other embodiments, the pain is due to inflammation of a joint, tendon, nerve, or muscle. In other embodiments, the pain is associated with a painful trigger point or tissue injury. In other embodiments, the pain is visceral pain. In yet other embodiments, the pain is due to a metabolic disease (e.g., diabetes, hemochromatosis, or Wilson&#39;s Disease), a hematologic disease (e.g., sickle cell disease), a coagulopathy (e.g., hemophilia A/B or factor VII deficiency), an abnormal deposition of substances into tissues (e.g., amyloid or lipodystrophy). In yet other embodiments, the pain is due to a change in local tissue structure, such as scarring, abnormal healing, lack of healing, or pressure in or on tissue. 
     More specific description of types of pain for treatment are provided below. 
     In certain embodiments, the pain is due to tendonitis, a myalgia (i.e., pain originating from disease and/or inflammation of muscle), bone or joint pain associated with inflammation, bone or joint pain due to an injury, or bone or joint pain due to arthritis associated with a degenerative disease, rheumatoid arthritis, osteoarthritis, or other arthritic condition. In yet other embodiments, the pain is due to bursitis, a sprain, a fracture, surgery, ligament inflammation, or ligament damage. 
     In certain embodiments, the pain is due to a tumor. The pain due to a tumor may be pain due to a metastatic tumor. In certain embodiments, the tumor may occur in the breast, kidney, brain, colon, colorectal tissue, prostate, cervix, uterus, lung, or bone. In certain other embodiments, the tumor may occur in the breast, kidney, brain, colon, colorectal tissue, prostate, cervix, uterus, or lung. In yet other embodiments, the tumor may occur in the skin, muscle, ovary, stomach, a blood vessel, cartilage, sinus, esophagus, eye, pancreas, liver, gall bladder, testes, lymph node, bladder, or a nerve. In yet other embodiments, the pain is due to a liquid tumor. The tumor may be further characterized by, for example, whether it is malignant or benign. 
     In certain embodiments, the pain to be treated is visceral pain. In certain other embodiments, the pain to be treated is nociceptive pain (i.e., pain transmitted across intact neuronal pathways), neuropathic pain (i.e., pain caused by damage to neural structures), pain from nerve injury (i.e., a neuroma or neuroma in continuity), pain from a neuralgia (i.e., pain originating from disease and/or inflammation of nerves), pain associated with a neurotransmitter-dysregulation syndrome (i.e., a disruption in quantity/quality of neurotransmitter molecules associated with signal transmission in normal nerves), or pain associated with an orthopedic disorder such as a condition of the foot, knee, hip, spine, shoulder, elbow, hand, head, or neck. In yet other embodiments, the pain to be treated is pain from a therapeutic intervention (e.g., chemotherapy, radiation, a toxin) or pain associated with tissue deposition of a material (e.g., an amyloid, a lipodystrophy, or crystal deposition disease). 
     Exemplary types of nociceptive pain include, for example, post-operative pain, a cluster headache, dental pain, surgical pain, pain resulting from a severe burn, post-partum pain, angina, genito-urinary tract pain, pain associated with a sports injury (e.g., tendonitis or bursitis), pain due to joint degeneration, and pain due to prostatitis or cystitis. In certain embodiments, the pain is bladder pain. Additional types of nociceptive pain include, for example, chronic headache (e.g., cluster headache), pain from scarring in any location, pain associated with a traumatic injury, pain due to prostatitis, gall bladder pain, and pain due to one or more of the following: a strain, sprain, fracture, dislocation, myalgia, or tissue damage. 
     Exemplary neuropathies include, for example, syndromes of acute ascending motor paralysis with variable disturbance of sensory function; syndromes of subacute sensorimotor paralysis; syndromes of acquired forms of chronic sensorimotor polyneuropathy; syndromes of determined forms of genetic chronic polyneuropathy; syndromes of recurrent or relapsing polyneuropathy; and syndromes of mononeuropathy or multiple neuropathies. Exemplary syndromes of acute ascending motor paralysis include acute idiopathic polyneuritis, Landry-Guillain-Barre Syndrome, acute immune-mediated polyneuritis, infectious mononucleosis polyneuritis, hepatitis polyneuritis, diptheric polyneuropathy, porphyric polyneuropathy, toxic polyneuropathy (e.g., thallium), acute axonal polyneuropathy, acute panautonomic neuropathy, vaccinogenic, serogenic, paraneoplastic, metabolic, toxic, chemotherapeutic, radiation, an infiltrative neuropathy, and polyarteretic and lupus polyneuropathy. 
     Exemplary syndromes of subacute sensorimotor paralysis include deficiency states (e.g., beriberi, pellagra, and vitamin B12); heavy metal/industrial solvent poisonings (e.g., arsenic or lead); drug use or overdose (e.g., isoniazid, disulfuram, platinum-based chemotherapy (e.g., cisplatin), vincristine, taxol, or chloramphenicol overdose); uremic polyneuropathy; metabolic (e.g., diabetes); infiltrative (e.g., amyloid, crystal, metal, or lipodystrophies); sarcoidosis; ischemic neuropathy and peripheral vascular disease; AIDS; and radiation (radiotherapy). 
     Exemplary syndromes of chronic sensorimotor include a carcinoma, myeloma and other malignancies; paraproteinemias; uremia; beriberi (usually subacute), diabetes, hypo/hyperthyroidism; rheumatic and connective tissue disease; amyloidosis; leprosy; Lyme disease, and sepsis. 
     Exemplary genetic chronic polyneuropathies include dominant mutilating sensory neuropathy (adult); recessive mutilating sensory neuropathy (childhood); congenital insensitivity to pain; spinocerebellar degenerations; Riley Day Syndrome; Universal Anesthesia Syndrome; polyneuropathies with metabolic disorder; and mixed sensorimotor-autonomic type polyneuropathies. 
     Exemplary recurrent/relapsing polyneuropathies include idiopathic polyneuritis; porphyria; chronic inflammatory polyradiculoneuropathy; mononeuritis multiplex; beriberi/drug overdose; refsum disease and tangier disease. 
     Exemplary mono/multiple neuropathies include pressure palsies; traumatic neuropathies (e.g., irradiation or electrical injury); serum; vaccinogenic (e.g., rabies, smallpox); herpes zoster; neoplastic infiltration; leprosy; diptheretic wound infections; migrant sensory neuropathy; shingles; and post-herpetic neuralgia. 
     Neurotransmitter-dysregulation pain syndromes include, for example, generalized syndromes, localized syndromes, craniofascial pain, vascular disease, rectal pain, perineum pain, external genitalia pain, chronic regional pain syndrome, and local syndromes of the leg/foot. 
     Exemplary generalized syndromes include stump pain, causalgia, reflex sympathetic dystrophy, fibromyalgia or local and/or diffuse myofascial pain and burns. Exemplary localized syndromes include trigeminal neuralgia; acute herpes zoster; panautonomic neuralgia; geniculate neuralgia (Romsay Hunt Syndrome); glossopharyngeal neuralgia; vagus nerve neuralgia and occipital neuralgia. Craniofacial pain includes temporomandibular pain. Suboccipital and cervical musculoskeletal disorders include myofascial syndrome, which includes cervical, sprain cervical hyperextension (whiplash); sternocleidomastoid muscle; trapezius muscle; and stylohyoid process syndrome (Eagle&#39;s syndrome). Vascular disease includes Raynaud&#39;s disease; Raynaud&#39;s phenomenon; frostbite; erythema pernio (chilblains); acrocyanosis and livedo reticularis. Rectal, perineum and external genitalia pain include iliohypogastric neuralgia; iliolinguinal nerve; genotifemoral nerve and testicular pain. Local syndromes of the leg/foot include lateral cutaneous neuropathy (neuralgia paresthetica); obturator neuralgia; femoral neuralgia; sciatica neuralgia; interdigital neuralgia of the foot (Morton&#39;s metatarsalgia or neuroma); injection neuropathy and painful legs and moving toes. 
     In certain embodiments, the pain is due to chronic post-herniorrhaphy, Morton&#39;s neuroma, a mastectomy, a median sternotomy, an orthopedic disorder, bursitis, tendonitis, ligamentous injury, meniscal injury, back/neck pain, a heel spur, or open or laparoscopic cholecystectomy. 
     Exemplary orthopedic disorders that may cause pain contemplated for treatment using formulations described herein include, for example, disorders of the knee, shoulders, back, hip, spine, elbows, foot, hand and other disorders, which involve pain at a specific site or body space. Orthopedic disorders affecting these locations include, for example, bursitis, tendonitis, ligamentous pain, chostochondritis, osteoarthritis, and rheumatoid arthritis (or other inflammatory or autoimmune diseases). Bursitis often occurs in multiple different locations including, for example, the shoulder (subacromial or subdeltoid bursitis). Other sites include the olecranon (miners&#39; elbow), prepatellar (housemaid&#39;s knee) or suprapatellar, retrocalcaneal (Achilles), iliopectineal (iliopsoas) of the hip, anserine (medial inferior, tibial plateau, ischial (tailor&#39;s or weaver&#39;s bottom)) of the pelvis, greater trochanteric of the femur, and first metatarsal head (bunion). Bursitis may be caused by trauma, chronic overuse, inflammatory arthritis (e.g., gout, pseudogout, and rheumatoid arthritis, other inflammatory diseases [immune/genetic]), or acute or chronic infection (e.g., pyogenic organisms, particularly  Staphylococcus aureus ; tuberculosis organisms), as well as post-infectious rheumatic diseases (e.g., chronic Lyme Disease and post-infectious arthritis). Orthopedic disorders of the foot include, for example, heel spurs, corns, bunions, a neuroma (e.g., Morton&#39;s neuroma), arthritis of the foot (e.g., osteoarthritis), hammertoes, ankle sprain, fractures of the ankle or metatarsals or sesamoid bone or toes, plantar fasciitis and injuries to the Achilles tendon. In certain embodiments, the pain is due to a bunion. 
     Orthopedic disorders of the hand include, for example, arthritis, carpal tunnel syndrome, ganglion cysts, tendon problems such as lateral epicondylitis, medial epicondylitis, rotator cuff tendonitis, De Quervian&#39;s tenosynovitis, and trigger finger/trigger thumb. Other orthopedic disorders include, for example, Paget&#39;s disease, scoliosis, soft-tissue injuries such as contusions, sprains and strains, long bone fractures, short bone fractures, small bone fractures, and various other sports or traumatic injuries, some of which include patellar tendonitis, lumbar strain, and cervical strain. 
     In certain embodiments, the pain is chronic pain. In certain embodiments, the pain is acute pain. 
     In certain embodiments, the pain arises from the capsule of a joint, a degenerative disc, or a lesion (e.g., a cyst). 
     In yet other embodiments, the pain is one or more of the types of pain described in U.S. Pat. Nos. 5,962,532 and 8,420,600, which are hereby incorporated by reference. 
     Joint Pain 
     The pain for treatment may be pain emanating from a joint, such as a joint selected from the group consisting of knee, elbow, hip, sternoclavicular, temporomandibular, shoulder, spine, wrist, ankle, a joint in the hand, and a joint in the foot. Accordingly, in certain embodiments, the pain is joint pain. In certain embodiments, the pain is pain in a knee joint, hip joint, shoulder joint, a sterno-manubrial joint, an acromioclavicular joint, a tempo mandibular joint, elbow joint, a carpal joint, a tarsal joint, a facet joint, or a metatarsal joint. In certain embodiments, the pain is pain in a knee joint, hip joint, shoulder joint, elbow joint, carpal joint, tarsal joint, or metatarsal joint. In certain embodiments, the joint pain is pain in a knee joint. In certain other embodiments, the joint pain is pain in a carpal joint or a tarsal joint. 
     In certain embodiments, the patient suffers from an inflammatory, traumatic, post-traumatic, post-surgical, autoimmune, genetic or congenital defect of the joint. In certain embodiments, the patient suffers from an inflammatory, autoimmune, genetic or congenital defect of the joint. In certain embodiments, the patient suffers from osteoarthritis of the joint. In certain other embodiments, the patient suffers from rheumatoid arthritis of the joint. 
     In certain embodiments, the joint is an osteoarthritic joint selected from a knee, hip, carpal-metacarpal joint, metatarsal joint, ankle, acromioclavicular joint, wrist, elbow, finger joint, vertebral joint, or temporal mandibrial joint. In certain embodiments, the joint is an osteoarthritic knee joint. 
     In a preferred embodiment, the pain to be treated is joint pain in a knee joint affected by osteoarthritis. 
     In certain other embodiments, the joint is a degenerative disc joint. Exemplary disc joints include a lumbar joint, thoracic joint, or cervical joint. 
     Route of Administration 
     The formulations are optimal for administration by injection, though the formulations may be administered by any of the medically accepted routes of administration that a physician of ordinary skill deems safe and appropriate. Exemplary routes of administration include injection into a joint, injection into a nerve or into tissue in proximity to a nerve, and injection into the spinal canal. In certain embodiments, the administering comprises injecting the formulation at or near the site of pain in the patient. In certain embodiments, the administering is intra-articular injection or intrathecal injection. In certain embodiments, the administering is intra-articular injection. In certain embodiments, the administering is intrathecal injection. In certain embodiments, the administering is epidural injection. In certain embodiments, the administering is injection to the spine, such as into a spinal disc. 
     In yet other embodiments of the therapeutic methods, the administering comprises injecting the formulation into a joint to treat joint pain. In yet other embodiments, the administering comprises injecting the formulation into the intra-articular space of a joint. In yet other embodiments, the administering comprises injecting the formulation into the intra-articular space of a knee joint to treat knee joint pain. In yet other embodiments, the method comprises cooling said joint before, and optionally after, injecting said formulation. 
     In yet other embodiments, the administering comprises intrathecal injection of the formulation to the patient. 
     In certain preferred embodiments, the administering comprises injecting the formulation into a joint to treat joint pain. In other preferred embodiments, the formulation is administered to the joint by intra-articular injection. In still other preferred embodiments, the administering comprises injecting the formulation into the intra-articular space of a knee joint to treat knee joint pain, such as osteoarthritic knee joint pain in a human. 
     In yet other embodiments, the formulation is administered by subcutaneous delivery, intrathecal delivery, intramuscular delivery, pulmonary delivery, topical delivery (e.g., a gel, ointment, lotion, or transdermal), oral delivery (e.g., delayed release formulation), or intra-vesicular delivery (e.g., for delivery to a bladder). 
     Attenuation of Initial Hyperalgesic Effect of Capsaicin 
     An anesthetic agent can be administered to the patient in order to attenuate any initial hyperalgesic effect caused by administration of the capsaicin in the formulation. The anesthetic agent can be administered directly to the site in which the capsaicin will be administered, or at a remote site that causes anesthesia at the site where the capsaicin will be administered. For example, epidural regional anesthesia can be provided to patients to which the capsaicin will be administered at a site located from the waist down. 
     In certain embodiments, the anesthetic agent is a caine alkaloid. Exemplary caine alkaloids include lidocaine, dibucaine, bupivacaine, ropivacaine, etidocaine, tetracaine, procaine, chlorocaine, prilocaine, mepivacaine, xylocaine, 2-chloroprocaine, and pharmaceutically acceptable salts thereof. 
     The dose of local anesthetic will depend on the anesthetic being administered as well as the site where the local anesthetic is administered. For example, in embodiments where the local anesthetic is administered via a regional block (e.g., an ankle block), the dose of anesthetic may range from about 1 mL up to about 30 mL of a 0.5% solution of anesthetic agent (e.g., bupivacaine). In other embodiments, a dose of up to 5 mg/kg of a solution containing 0.25% to 5% of anesthetic agent (e.g., lidocaine) may be administered as a nerve block, such as by administration to the site of pain or an area proximal to the site of pain. In yet other embodiments, the dose of local anesthetic may range from about 0.5 mL to about 60 mL of a 0.25% to 5% solution of anesthetic agent. 
     In certain embodiments, the anesthetic agent is administered as a proximal, regional, somatic, or neuraxial block. Alternatively, a general anesthetic (or other agent that causes sedation) may be used to attenuate any initial hyperalgesic effect caused by administration of capsaicin. 
     In certain other embodiments, any initial pain due to the caspaicin injection may be attenuated by use of an opioid administered orally, or by an alternative systemic route (e.g., intravenously or subcutaneously). 
     Accordingly, in one aspect, the therapeutic methods for treating pain further comprise administering an anesthetic, concurrently or prior to the aqueous capsaicin injectable formulation, in an amount and location effective to attenuate any initial hyperalgesic effect of the capsaicin. In certain embodiments, the anesthetic is a general anesthetic. In certain embodiments, the anesthetic is a local anesthetic. In certain embodiments, the local anesthetic is a caine alkaloid. In certain embodiments, the local anesthetic is lidocaine or a pharmaceutically acceptable salt thereof. 
     Additional description of procedures and agents that may be used to attenuate any initial hyperalgesic effect caused by administration of the capsaicin-containing formulation are described in U.S. Pat. No. 5,962,532, which is hereby incorporated by reference. 
     Patients for Treatment 
     The method may be further characterized according to the patient to be treated. 
     Accordingly, in certain embodiments, the patient is an adult human. In other embodiments, the patient is a canine. 
     Duration of Pain Relief 
     The method may be further characterized according to the duration of pain relief provided. For example, in certain embodiments, the method provides relief from said pain for a duration of at least 3 months. In other embodiments, the method provides relief from said pain for a duration of at least 6 months. In other embodiments, the method provides relief from said pain for a duration of from about 1 month to about 9 months, from about 3 months to about 9 months, from about 3 months to about 7 months, or about 3 months to about 6 months. 
     Dose of Capsaicin Administered to the Patient 
     The dose of capsaicin administered to the patient may depend on, for example, the type of pain to be treated and may be selected according to dose-selection procedures known to those skilled in the art. In certain embodiments, the dose of capsaicin administered to a patient as a single administration is from about 1 μg to about 5000 μg, from about 250 μg to about 2000 μg, or 500 μg to about 1000 μg. In certain embodiments, the administering is injecting at or near the site of pain a single dose of the capsaicin in an amount of from about 1 μg to about 5000 μg. In certain embodiments, the administering is injecting at or near the site of pain a single dose of the capsaicin in an amount of from about 250 μg to about 2000 μg. In certain embodiments, the administering is injecting at or near the site of pain a single dose of the capsaicin in an amount of from about 500 μg to about 1000 μg. In certain embodiments, the administering is injecting at or near the site of pain a single dose of the capsaicin in an amount of about 1000 μg. 
     V. Kits for Use in Medical Applications 
     Another aspect of the invention provides a kit for treating a disorder. The kit comprises: i) instructions for treating pain, such as osteoarthritic knee joint pain; and ii) an aqueous capsaicin injectable formulation described herein, such as one of the formulations described in Tables 1-5. 
     The description above describes multiple aspects and embodiments of the invention. The patent application specifically contemplates all combinations and permutations of the aspects and embodiments. 
     EXAMPLES 
     The invention now being generally described, will be more readily understood by reference to the following examples, which are included merely for purposes of illustration of certain aspects and embodiments of the present invention, and are not intended to limit the invention. 
     Example 1—Analysis of Capsaicin Solubility of Multiple Aqueous Formulations Containing a Solubilizing Agent 
     Multiple aqueous formulations were prepared and analyzed to determine the amount of dissolved capsaicin. The formulations contained different solubilizing agents to increase the amount of capsaicin dissolved in the aqueous medium. The experimental procedures and results are described below. 
     Part I—Analysis of Capsaicin Solubility in Multiple Aqueous Formulations 
     Aqueous formulations were prepared containing capsaicin and a solubilizing agent selected from Tween 20, Tween 80, Kolliphor ELP, Kolliphor HS 15, Kollidon 12 PF, and Kollidon 17 PF as further defined below. Experimental procedures and results are described below. 
     Experimental Procedures 
     The equilibrium solubility of capsaicin was determined in a series of aqueous solutions. Six different types of vehicles were prepared at three different concentrations each. Tween 20 solutions were prepared at a range of 0.2% to 10% (w/v). Tween 80 solutions were prepared at a range of 0.2% to 1.0% (w/v). Kolliphor ELP and Kolliphor HS 15 solutions were both prepared at a range of 5% to 20% (w/v). Kollidon 12 PF solutions were prepared at a range of 2.5% to 10% (w/v). Kollidon 17 PF solutions were prepared at a range of 0.5% to 2.0% (w/v). 
     For each test solution, quantities of 20-30 mg of capsaicin were added to a micro centrifuge tubes. A volume of 1.5 mL of the appropriate test vehicle was added to each to create a suspension. The capped tubes were mixed on a laboratory rotator at ambient temperature. At approximately 48 hours after sample preparation, the tubes were removed from the rotator and centrifuged to separate the solid phase from the solution. An aliquot of the supernatant was withdrawn from each sample and diluted as necessary for HPLC analysis to determine the solution concentration of the capsaicin. The pH of the supernatant was measured 48 hours after preparation and the appearance of solid and supernatant were noted. 
     As reported in the literature, Tween 20 is also known as Polysorbate 20, which has the chemical name polyoxyethylene (20) sorbitan monolaurate. Tween 80 is also known as Polysorbate 80, which has the chemical name polyoxyethylene (20) sorbitan monooleate. Kolliphor ELP has CAS Registry No. 61791-12-6, and is a composition sold by BASF under the chemical name polyoxyl-35-castor oil and marketed by BASF as Kolliphor™ ELP; the composition is made by reacting castor oil with ethylene oxide in a molar ratio of 1:35. The Kolliphor HS 15 has CAS Registry No. 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15. Kollidon 12 PF is a polyvinylpyrrolidone having a weight-average molecular weight in the range of 2,000 to 3,000 g/mol, sold by BASF under the name KOLLIDON® 12 PF. Kollidon 17 PF is a polyvinylpyrrolidone having a weight-average molecular weight in the range of 7,000 to 11,000 g/mol, sold by BASF under the name KOLLIDON® 17 PF. 
     Results 
     Results from the above analysis are presented in Table 6. For all test solutions except those containing Kollidon12 PF or Kollidon17 PF, the observed concentration of capsaicin increased concordant with increasing surfactant concentration. With the exception of Kollidon 12 PF and Kollidon 17 PF, at least one test solution from each of different solubilizing agents reached the minimum target concentration of capsaicin of 1 mg/mL capsaicin. Both Kollidon 12 PF and Kollidon 17 PF solutions, at all strengths, failed to reach the minimum target concentration of 1 mg/mL capsaicin. The highest concentrations of capsaicin were observed in the 20% strength Kolliphor ELP {c(Capsaicin)=13.0 mg/mL} and 20% Kolliphor HS 15 {c(Capsaicin)=12.2 mg/mL} solutions. 
     The observed pH-values in the supernatants of the test solutions ranged from pH=3.88 to pH=7.27. Appearances of both the liquid supernatant and the remaining solid were observed to be clear and as at initial solution preparation. For all samples that had remaining solid, the solid appeared white and had no notable difference from its starting consistency. 
     After centrifugation of the sample containing 20% Kolliphor ELP no solid residue could be detected, which signifies that the equilibrium solubility for Capsaicin in this vehicle was not reached and is greater than the observed c(Capsaicin)=13.0 mg/mL. For the 20% Kolliphor HS vehicle, the amount of pelleted solid from centrifugation was at the limit of detection. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 6 
               
               
                   
               
               
                 Sample 
                 Observed 
                   
                   
                   
               
               
                 (amount in weight 
                 [Capsaicin] 
                 pH 
                 appearance 
                 appearance 
               
               
                 percent) 
                 mg/(mL) 
                 (at 48 hr) 
                 pellet 
                 supernatant 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Tween 20 (0.2%) 
                 0.146 
                 6.78 
                 white 
                 clear 
               
               
                 Tween 20 (2%) 
                 1.11 
                 6.16 
                 white 
                 clear 
               
               
                 Tween 20 (10%) 
                 5.39 
                 6.03 
                 white 
                 clear 
               
               
                 Tween 80 (0.2%) 
                 0.233 
                 6.45 
                 white 
                 clear 
               
               
                 Tween 80 (0.5%) 
                 0.245 
                 7.27 
                 white 
                 clear 
               
               
                 Tween 80 (1.0%) 
                 1.00 
                 7.03 
                 white 
                 clear 
               
               
                 Kolliphor ELP (5%) 
                 4.20 
                 5.61 
                 white 
                 clear 
               
               
                 Kolliphor ELP (10%) 
                 8.14 
                 5.21 
                 white 
                 clear 
               
               
                 Kolliphor ELP (20%) 
                 13.0 
                 4.70 
                 none 
                 clear 
               
               
                 Kolliphor HS 15 (5%) 
                 3.81 
                 6.65 
                 white 
                 clear 
               
               
                 Kolliphor HS 15 (10%) 
                 7.18 
                 6.97 
                 white 
                 clear 
               
               
                 Kolliphor HS 15 (20%) 
                 12.2 
                 7.01 
                 white 
                 clear 
               
               
                 Kollidon 12 (2.5%) 
                 0.276 
                 4.22 
                 white 
                 clear 
               
               
                 Kollidon 12 (5%) 
                 0.624 
                 4.00 
                 white 
                 clear 
               
               
                 Kollidon 12 (10%) 
                 0.378 
                 3.88 
                 white 
                 clear 
               
               
                 Kollidon 17 (0.5%) 
                 0.150 
                 5.75 
                 white 
                 clear 
               
               
                 Kollidon 17 (1.0%) 
                 0.247 
                 4.66 
                 white 
                 clear 
               
               
                 Kollidon 17 (2.0%) 
                 0.199 
                 4.20 
                 white 
                 clear 
               
               
                   
               
            
           
         
       
     
     Part II—Capsaicin Solubility in Cyclodextrin Solutions 
     Aqueous formulations were prepared containing capsaicin and a solubilizing agent selected from hydroxypropyl-β-cyclodextrin and captisol (i.e., sodium sulfobutyl ethers β-cyclodextrin). Experimental procedures and results are described below. 
     Experimental Procedures 
     For each cyclodextrin solution, quantities of about 20-30 mg of capsaicin were suspended in 1.5 mL of the respective cyclodextrin solution. The capped tubes were mixed on a laboratory rotator at ambient temperature. At approximately 48 hours after sample preparation, the tubes were removed from the rotator and centrifuged to separate the solid phase from the solution. An aliquot of the supernatant was withdrawn from each sample and diluted as necessary for HPLC analysis to determine the solution concentration of the capsaicin, which was quantitated relative to the reference standard. The pH of the supernatant was measured and the appearance of both the supernatant and the solid were noted at 48 hours. 
     Results 
     Results from the above analysis are presented in Table 7. For both cyclodextrins tested, at all solution strengths, at least 2 mg/mL capsaicin was observed. Hydroxypropyl-3-cyclodextrin had slightly higher concentrations of capsaicin than captisol for all solution strengths. The pH of the solutions ranged from 7.00 to 7.94. The liquid portion of each sample was clear and appeared unchanged from its original state. The solid portion of each sample was white, granular, and appeared as it did prior to the addition of the cyclodextrin solution. The 25% solutions of both cyclodextrins had very little remaining solid. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 7 
               
               
                   
               
               
                   
                 Peak  
                 Observed 
                 appear- 
                 appear- 
                 pH 
               
               
                   
                 area 
                 [Capsaicin], 
                 ance 
                 ance 
                 (at  
               
               
                 Sample 
                 (mAU) 
                 mg/mL 
                 pellet 
                 supernatant 
                 48 hr) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                  5%  
                 4247905 
                 2.39 
                 White 
                 clear 
                 7.32 
               
               
                 Hydroxypropyl- 
                   
                   
                   
                   
                   
               
               
                 β-cyclodextrin 
                   
                   
                   
                   
                   
               
               
                 10%  
                 7891725 
                 4.45 
                 White 
                 clear 
                 7.44 
               
               
                 Hydroxypropyl- 
                   
                   
                   
                   
                   
               
               
                 β-cyclodextrin 
                   
                   
                   
                   
                   
               
               
                 25%  
                 20541037 
                 11.6 
                 White 
                 clear 
                 7.00 
               
               
                 Hydroxypropyl- 
                   
                   
                   
                   
                   
               
               
                 β-cyclodextrin 
                   
                   
                   
                   
                   
               
               
                  5% Captisol 
                 3734548 
                 2.10 
                 White 
                 clear 
                 7.94 
               
               
                 10% Captisol 
                 6561988 
                 3.70 
                 White 
                 clear 
                 7.65 
               
               
                 25% Captisol 
                 14660216 
                 8.26 
                 White 
                 clear 
                 7.23 
               
               
                   
               
            
           
         
       
     
     Part III—Capsaicin Solubility in Additional Aqueous Solutions 
     Aqueous formulations were prepared containing capsaicin and an additive. The solubility of capsaicin was also analyzed in deionized water. Experimental procedures and results are described below. 
     Experimental Procedures 
     For each of the six solutions, quantities of about 20-30 mg of capsaicin were added to each of six micro centrifuge tubes. A volume of 1.5 mL of the appropriate solution was added to each to create a suspension. The capped tubes were mixed on a laboratory rotator at ambient temperature. At approximately 7 days after sample preparation, the tubes were removed from the rotator and centrifuged to separate the solid phase from the solution. An aliquot of the supernatant was withdrawn from each sample and diluted as necessary for HPLC analysis to determine the solution concentration of the capsaicin, which was quantitated relative to the reference standard. The pH-values of the supernatant were measured and the appearance of both the supernatant and the pelleted solid were noted. 
     Results 
     Results from the above analysis are presented in Table 8. The lowest concentration of the capsaicin was observed in deionized water with c(Capsaicin)=7.6 μg/mL while solubilization of capsaicin in aqueous 2.5% glycerol resulted in the highest observed concentration of capsaicin with c(Capsaicin)=38 μg/mL. 
     
       
         
           
               
               
               
               
               
               
             
               
                 TABLE 8 
               
               
                   
               
               
                   
                 Peak 
                 Observed 
                   
                   
                 pH 
               
               
                   
                 area 
                 [Capsaicin], 
                 appearance 
                 appearance 
                 (at 7  
               
               
                 Sample 
                 (mAU) 
                 mg/mL 
                 pellet 
                 supernatant 
                 days) 
               
               
                   
               
             
            
               
                 Water 
                 135565 
                 0.008 
                 White 
                 clear 
                 4.53 
               
               
                 5% mannitol 
                 381253 
                 0.021 
                 White 
                 clear 
                 5.53 
               
               
                 5% mannitol, 0.1M 
                 513817 
                 0.020 
                 White 
                 clear 
                 4.73 
               
               
                 pH 5 Citrate 
                   
                   
                   
                   
                   
               
               
                 5% mannitol, 0.1M 
                 378148 
                 0.021 
                 White 
                 clear 
                 5.86 
               
               
                 pH 6 Citrate 
                   
                   
                   
                   
                   
               
               
                 5% mannitol, 0.1M 
                 484164 
                 0.027 
                 White 
                 clear 
                 5.25 
               
               
                 pH 5 Acetate 
                   
                   
                   
                   
                   
               
               
                 2.5% glycerol in 
                 682320 
                 0.038 
                 White 
                 clear 
                 6.47 
               
               
                 water 
               
               
                   
               
            
           
         
       
     
     Example 2—Stability Analysis of Exemplary Formulations 
     The aqueous formulations in Table 9 below were subjected to stability analysis by storage at 5° C., 25° C., 40° C., and/or 60° C., followed by analytical analysis to determine the amount of capsaicin and/or impurities in the formulation. Results are provided below. The abbreviation BHT refers to dibutylhydroxytoluene. The abbreviation “EDTA” refers to ethylenediaminetetraacetic acid. The Kolliphor HS-15 has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15. The phrase “Average Particles Per Container” refers to the average number of particles observed in a container, where the container held approximately 1.5 mL of aqueous formulation to be analyzed. 
     
       
         
           
               
               
               
             
               
                   
                 TABLE 9 
               
               
                   
                   
               
             
            
               
                   
                 Solution 1A: 
                 Solution 1P: 
               
               
                   
                   
               
               
                   
                 1 mg/ml Capsaicin 
                 2% Kolliphor HS-15 
               
               
                   
                 2% Kolliphor HS-15 
                 20 mM citrate buffer 
               
               
                   
                 20 mM citrate buffer 
                 0.1% disodium EDTA 
               
               
                   
                 0.1% disodium EDTA 
                 0.01% BHT 
               
               
                   
                 0.01% BHT 
                 0.625% NaCl 
               
               
                   
                 0.625% NaCl 
                 q.s. water 
               
               
                   
                 q.s. water 
               
               
                   
                   
               
               
                   
                 Solution 2A: 
                 Solution 3A: 
               
               
                   
                   
               
               
                   
                 2 mg/ml Capsaicin 
                 1 mg/ml Capsaicin 
               
               
                   
                 4% Kolliphor HS-15 
                 2% Kolliphor HS-15 
               
               
                   
                 20 mM citrate buffer 
                 0.1% disodium EDTA 
               
               
                   
                 0.1% disodium EDTA 
                 0.01% BHT 
               
               
                   
                 0.01% BHT 
                 3.15% Dextrose 
               
               
                   
                 0.625% NaCl 
                 q.s. water 
               
               
                   
                 q.s. water 
               
               
                   
                   
               
               
                   
                 Solution 3P: 
                 Solution 4A: 
               
               
                   
                   
               
               
                   
                 2% Kolliphor HS-15 
                 2 mg/ml Capsaicin 
               
               
                   
                 20 mM citrate buffer 
                 4% Kolliphor HS-15 
               
               
                   
                 0.1% disodium EDTA 
                 20 mM citrate buffer 
               
               
                   
                 0.01% BHT 
                 0.1% disodium EDTA 
               
               
                   
                 3.15% Dextrose 
                 0.01% BHT 
               
               
                   
                 q.s. water 
                 3.15% Dextrose 
               
               
                   
                   
                 q.s. water 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 1A 
               
               
                   
               
               
                 (A) Summary of results for the Solution 1A formulation at 5° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                   
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 Testing time, 
                 Solution 1A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 1.0 
                 873 
                 1856 
                 1842 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.005%) 
                 (0.005%)  
               
               
                 1 1   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 2   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 1   
                 Clear and 
                 5.5 
                   
                   
                 1.0 
                 N/A 
                 N/A 
                 1864 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                 (0.005%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time,  
                   
                   
                   
                   
                   
                   
               
               
                   
                 5° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 1031 
                 1751 
                 5490 
                 30126 
                 34429382 
                 28100  
               
               
                   
                   
                 (0.003%) 
                 (0.005%) 
                 (0.016%) 
                 (0.087%) 
                 (99.794%) 
                 (0.081%) 
               
               
                   
                 1 1   
                   
                   
                   
                   
                   
                   
               
               
                   
                 3 2   
                   
                   
                   
                   
                   
                   
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 33913917 
                 8866 
               
               
                   
                   
                   
                   
                   
                   
                 (99.870%) 
                 (0.026%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2A 
               
               
                   
               
               
                 (B) Summary of results for the Solution 1A formulation at 25° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 25° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 19.40 
                 1.10 
                 1.0 
                 N/A 
                 1858 
                 1834 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.005%) 
                 (0.005%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 1.0 
                 678 
                 1881 
                 1844 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.005%) 
                 (0.006%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 N/A 
                 2151 
                 4995 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.007%) 
                 (0.016%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 40.60 
                 1.30 
                 1.0 
                 N/A 
                 1759 
                 1914 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.005%) 
                 (0.006%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 25° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 886 
                 2919 
                 7432 
                 32759 
                 34570267 
                 23242  
               
               
                   
                   
                 (0.003%) 
                 (0.008%) 
                 (0.021%) 
                 (0.095%) 
                 (99.795%) 
                 (0.067%) 
               
               
                   
                 1 1   
                 1073  
                 1538 
                 5778 
                 30665 
                 34565985 
                 7828 
               
               
                   
                   
                 (0.003%) 
                 (0.004%) 
                 (0.017%) 
                 (0.089%) 
                 (99.852%) 
                 (0.023%) 
               
               
                   
                 3 2   
                 1642  
                 2491 
                 4649 
                 35711 
                 31442165 
                 21338  
               
               
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.015%) 
                 (0.113%) 
                 (99.631%) 
                 (0.068%) 
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 33979632 
                 6676 
               
               
                   
                   
                   
                   
                   
                   
                 (99.871%) 
                 (0.020%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2A-1 
               
             
            
               
                   
               
               
                 (C) 
               
               
                 Additional peaks for Solution 1A formulation at 25° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                   
                 T = 3 m extra 
                   
               
               
                 HPLC Purity, 
                 peaks 
                   
               
               
                 Area % 
                 Peak @ 15.3 
                 Peak @ 34.4 
               
               
                 Peak @ 7.9 min 
                 min 
                 min 
               
               
                   
               
               
                 14113 
                 6702 (0.021%) 
                 4917 (0.014%) 
               
               
                 (0.045%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3A 
               
               
                   
               
               
                 (D) Summary of results for the Solution 1A formulation at 40° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 45.80 
                 2.00 
                 1.0 
                 N/A 
                 1923 
                 1856 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.006%) 
                 (0.005%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 1.0 
                 677 
                 2146 
                 1898 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.006%) 
                 (0.005%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 1591 
                 3347 
                 4381 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.005%) 
                 (0.011%) 
                 (0.016%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 66.70 
                 1.70 
                 1.0 
                 N/A 
                 10294  
                 1654 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.030%) 
                 (0.005%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 40° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 985 
                 2006 
                 6269 
                 30643 
                 34576418 
                 7561 
               
               
                   
                   
                 (0.003%) 
                 (0.006%) 
                 (0.018%) 
                 (0.088%) 
                 (99.852%) 
                 (0.022%) 
               
               
                   
                 1 1   
                 928 
                 1871 
                 5730 
                 30312 
                 34727820 
                 11056  
               
               
                   
                   
                 (0.003%) 
                 (0.005%) 
                 (0.016%) 
                 (0.087%) 
                 (99.843%) 
                 (0.032%) 
               
               
                   
                 3 2   
                 1668  
                 2218 
                 4523 
                 32761 
                 30846401 
                 17222  
               
               
                   
                   
                 (0.005%) 
                 (0.007%) 
                 (0.015%) 
                 (0.106%) 
                 (99.642%) 
                 (0.056%) 
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 29082 
                 33990190 
                 5366 
               
               
                   
                   
                   
                   
                   
                 (0.085%) 
                 (99.841%) 
                 (0.016%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3A-1 
               
             
            
               
                   
               
               
                 (E) 
               
               
                 Additional peaks for Solution 1A formulation 
               
               
                 at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                   
                   
                 T = 3 m extra 
               
               
                   
                 HPLC Purity, 
                 peaks 
               
               
                   
                 Area % 
                 Peak @ 15.3 
               
               
                   
                 Peak @ 7.9 min 
                 min 
               
               
                   
                   
               
               
                   
                 13886 
                 5885 (0.019%) 
               
               
                   
                 (0.045%) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3A-2 
               
             
            
               
                   
               
               
                 (F) 
               
               
                 Additional peaks for Solution 1A formulation at  
               
               
                 40° C. at t = 6 months. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 6 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 7.9 min 
                 — 
               
               
                   
                 3717 (0.011%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4A 
               
               
                   
               
               
                 (G) Summary of results for the Solution 1A formulation at 60° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 60° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                     0 1   
                 Clear and 
                 5.5 
                   
                   
                 1.0 
                 656 
                 2174 
                 2035  
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.006%) 
                 (0.006%) 
               
               
                     1 1   
                 Cloudy, then  
                 5.5 
                   
                   
                 1.0 
                 892 
                 3336 
                 627 
               
               
                   
                 clears up after  
                   
                   
                   
                   
                 (0.003%) 
                 (0.01%) 
                 (0.002%) 
               
               
                   
                 5 min 
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 60° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                     0 1   
                 1391  
                 2705 
                 6913 
                 29898 
                 34348643 
                 6216 
               
               
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.020%) 
                 (0.087%) 
                 (99.849%) 
                 (0.018%) 
               
               
                   
                     1 1   
                 853 
                 1705 
                 4910 
                 30368 
                 34698973 
                 11505  
               
               
                   
                   
                 (0.002%) 
                 (0.005%) 
                 (0.014%) 
                 (0.087%) 
                 (99.829%) 
                 (0.033%) 
               
               
                   
                 3 
                   
                   
                   
                   
                   
                   
               
               
                   
                 6 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5A 
               
               
                   
               
               
                 (H) Summary of results for the Solution 1P formulation at 5° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                     0 1   
                 Clear and 
                 5.2 
                   
                   
                 0 
                 527 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (100%) 
                   
                   
               
               
                 1 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                     6 1   
                 Clear and 
                 5.2 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 5° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                     0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 3 
                   
                   
                   
                   
                   
                   
               
               
                   
                     6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 5A-1 
               
             
            
               
                   
               
               
                 (I) 
               
               
                 Additional peaks for Solution 1P formulation 
               
               
                 at 5° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 1 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 39.8 
                 — 
               
               
                   
                 min 
                   
               
               
                   
                 7691 (91.462%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6A 
               
               
                   
               
               
                 (J) Summary of results for the Solution 1P formulation at 25° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 25° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.3 
                 15.70 
                 0.60 
                 0 
                 693 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (100%) 
                   
                   
               
               
                 1 1   
                 Clear and 
                 5.3 
                   
                   
                 0 
                 697 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (100%) 
                   
                   
               
               
                 3 2   
                 Clear and 
                 5.3 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 1   
                 Clear and 
                 5.3 
                 33.70 
                 1.10 
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 25° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 1 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 3 2   
                 N/A 
                 N/A 
                 N/A 
                 22037 
                 N/A 
                 21266 
               
               
                   
                   
                   
                   
                   
                 (34.748%) 
                   
                 (33.532%) 
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 6A-1 
               
             
            
               
                   
               
               
                 (K) 
               
               
                 Additional peaks for Solution 1P formulation 
               
               
                 at 25° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                   
                   
                 T = 3 m extra 
               
               
                   
                 HPLC Purity, 
                 peaks 
               
               
                   
                 Area % 
                 Peak @ 15.3 
               
               
                   
                 Peak @ 7.9 min 
                 min 
               
               
                   
                   
               
               
                   
                 11261 
                 8856 (13.964%) 
               
               
                   
                 17.756%) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7A 
               
               
                   
               
               
                 (L) Summary of results for the Solution 1P formulation at 40° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.3 
                 26.00 
                 1.20 
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
               
               
                 1 1   
                 Clear and 
                 5.3 
                   
                   
                 0 
                 570 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (100%) 
                   
                   
               
               
                 3 2   
                 Clear and 
                 5.3 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 1   
                 Clear and 
                 5.3 
                 64.60 
                 3.20 
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 40° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 1 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 3 2   
                 N/A 
                 N/A 
                 N/A 
                 20712 
                 N/A 
                 18573 
               
               
                   
                   
                   
                   
                   
                 (40.96%) 
                   
                 (36.729%) 
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 7A-1 
               
             
            
               
                   
               
               
                 (M) 
               
               
                 Additional peaks for Solution 1P formulation 
               
               
                 at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                   
                   
                 T = 3 m extra 
               
               
                   
                 HPLC Purity, 
                 peaks 
               
               
                   
                 Area % 
                 Peak @ 34.4 
               
               
                   
                 Peak @ 7.9 min 
                 min 
               
               
                   
                   
               
               
                   
                 9574 (18.933%) 
                 1708 (0.061%) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 8A 
               
               
                   
               
               
                 (N) Summary of results for the Solution 1P formulation at 60° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 1P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 60° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                     0 1   
                 Clear and 
                 5.2 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
               
               
                     1 1   
                 Cloudy, then  
                 5.3 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 clears up  
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 after 5 min 
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
               
               
                   
               
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 60° C. 
                   
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                   
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                     0 1   
                   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                     1 1   
                   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 6 
               
               
                   
               
               
                 1Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 9A 
               
               
                   
               
               
                 (O) Summary of results for the Solution 2A formulation at 5° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 2A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                     0 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 2079 
                 4943 
                 4018 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.008%) 
                 (0.006%) 
               
               
                 1 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                     6 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 N/A 
                 5008 
                 6050 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.009%) 
                 (0.010%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 5° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                     0 1   
                 2496 
                 4587 
                 13424 
                 60045 
                 62109784 
                 26991 
               
               
                   
                   
                 (0.004%) 
                 (0.007%) 
                 (0.022%) 
                 (0.096%) 
                 (99.808%) 
                 (0.043%) 
               
               
                   
                 1 
                   
                   
                   
                   
                   
                   
               
               
                   
                 3 
                   
                   
                   
                   
                   
                   
               
               
                   
                     6 1   
                 2337 
                 4423 
                 N/A 
                 52022 
                 59537951 
                 11323 
               
               
                   
                   
                 (0.004%) 
                 (0.007%) 
                   
                 (0.087%) 
                 (99.897%) 
                 (0.019%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10A 
               
               
                   
               
               
                 (P) Summary of results for the Solution 2A formulation at 25° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 2A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 mm 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.6 
                 16.60 
                 0.40 
                 1.7 
                 1857 
                 4780 
                 4327 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.008%) 
                 (0.007%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 2868 
                 6146 
                 6318 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.005%) 
                 (0.010%) 
                 (0.010%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 1.6 
                 2901 
                 6621 
                 12531 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.005%) 
                 (0.012%) 
                 (0.023%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 38.00 
                 1.00 
                 1.7 
                 N/A 
                 6247 
                 6786 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.010%) 
                 (0.011%) 
               
               
                   
               
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 5° C. 
                   
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                   
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 mm 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                   
                 2490 
                 5098 
                 13402 
                 60901 
                 62158307 
                 6972 
               
               
                   
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.021%) 
                 (0.098%) 
                 (99.819%) 
                 (0.003%) 
               
               
                   
                 1 1   
                   
                 2434 
                 4829 
                 12911 
                 60510 
                 62234585 
                 6741 
               
               
                   
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.021%) 
                 (0.097%) 
                 (99.804%) 
                 (0.011%) 
               
               
                   
                 3 2   
                   
                 3404 
                 5277 
                 10081 
                 56265 
                 54007764 
                 24506 
               
               
                   
                   
                   
                 (0.005%) 
                 (0.010%) 
                 (0.019%) 
                 (0.104%) 
                 (99.608%) 
                 (0.043%) 
               
               
                   
                 6 1   
                   
                 1771 
                 N/A 
                 N/A 
                 N/A 
                 59784009 
                 5665 
               
               
                   
                   
                   
                 (0.003%) 
                   
                   
                   
                 (99.828%) 
                 (0.009%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10A-1 
               
             
            
               
                   
               
               
                 (Q) 
               
               
                 Additional peaks for Solution 2A formulation 
               
               
                 at 25° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 1 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                 Peak @ 18.8 
                 Peak @ 36.6 
               
               
                   
                 min 
                 min 
               
               
                   
                   
               
               
                   
                 6874 (0.0117%) 
                 1581 (0.003%) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 10A-2 
               
             
            
               
                   
               
               
                 (R) 
               
               
                 Additional peaks for Solution 2A formulation 
               
               
                 at 25° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m extra 
                   
               
               
                 Area % 
                 peaks 
                 Peak @ 15.3 
               
               
                 Peak @ 7.2 min 
                 Peak @ 7.9 min 
                 min 
               
               
                   
               
               
                 3084 (0.005%) 
                 15264 
                 13630 
               
               
                   
                 (0.028%) 
                 (0.025%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11A 
               
               
                   
               
               
                 (S) Summary of results for the Solution 2A formulation at 40° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 2A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.6 
                 10.90 
                 0.80 
                 1.7 
                 2010 
                 5711 
                 4450 
                 2426 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.009%) 
                 (0.007%) 
                 (0.004%) 
               
               
                 1 1   
                 Clear and 
                 5.6 
                   
                   
                 1.7 
                 2747 
                 6962 
                 5969 
                 2691 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.004%) 
                 (0.011%) 
                 (0.010%) 
                 (0.004%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 1.6 
                 3635 
                 8560 
                 10898  
                 2844 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.006%) 
                 (0.016%) 
                 (0.020%) 
                 (0.004%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 46.00 
                 1.80 
                 1.7 
                 2453 
                 13974  
                 6867 
                 1818 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.004%) 
                 (0.023%) 
                 (0.011%) 
                 (0.003%) 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 40° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 5381 
                 15241 
                 60560 
                 62197853 
                  6605 
                   
                   
               
               
                   
                   
                   
                 (0.009%) 
                 (0.024%) 
                 (0.097%) 
                 (99.834%) 
                 (0.011%) 
                   
                   
               
               
                   
                   
                 1 1   
                 4826 
                 12928 
                 60894 
                 62203800 
                 12505 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.021%) 
                 (0.098%) 
                 (99.815%) 
                 (0.02%) 
                   
                   
               
               
                   
                   
                 3 2   
                 4836 
                 13765 
                 60708 
                 53818012 
                 31825 
                   
                   
               
               
                   
                   
                   
                 (0.009%) 
                 (0.025%) 
                 (0.112%) 
                 (99.639%) 
                 (0.059%) 
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 50941 
                 59771249 
                  4219 
                   
                   
               
               
                   
                   
                   
                   
                   
                 (0.085%) 
                 (99.816%) 
                 (0.007%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11A-1 
               
             
            
               
                   
               
               
                 (T) 
               
               
                 Additional peaks for Solution 2A formulation 
               
               
                 at 40° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                 HPLC Purity, 
                 T = 1 m extra 
                   
               
               
                 Area % 
                 peaks 
                 Peak @ 36.6 
               
               
                 Peak @ 5.0 min 
                 Peak @ 5.9 min 
                 min 
               
               
                   
               
               
                 2084 (0.003%) 
                 1503 (0.002%) 
                 940 (0.002%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11A-2 
               
             
            
               
                   
               
               
                 (U) 
               
               
                 Additional peaks for Solution 2A formulation 
               
               
                 at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m extra 
                   
                   
                   
               
               
                 Area % 
                 peaks 
                 Peak @ 
                 Peak @  
                 Peak @  
               
               
                 Peak @ 5.7 min 
                 Peak @ 7.2 min 
                 7.9 min 
                 16.7 min 
                 38.3 min 
               
               
                   
               
               
                 3988 (0.007%) 
                 3616 (0.004%) 
                 13288 
                 9899  
                 3566  
               
               
                   
                   
                 (0.025%) 
                 (0.018%) 
                 (0.004%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 11A-3 
               
             
            
               
                   
               
               
                 (V) 
               
               
                 Additional peaks for Solution 2A formulation at 
               
               
                 40° C. at t = 6 months. 
               
            
           
           
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m  
                   
                 Peak @ 
                 Peak @ 
               
               
                 Area % 
                 extra peaks 
                 Peak @  
                 16.7 
                 38.3 
               
               
                 Peak @ 5.7 min 
                 Peak @ 7.2 min 
                 7.9 min 
                 min 
                 min 
               
               
                   
               
               
                 6021 (0.010%) 
                 N/A 
                 N/A 
                 N/A 
                 3566 (0.004%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12A 
               
               
                   
               
               
                 (W) Summary of results for the Solution 2A formulation at 60° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 2A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 60° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 1667 
                 6124 
                 4951 
                 2328 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.010%) 
                 (0.008%) 
                 (0.004%) 
               
               
                 1 1   
                 Cloudy, 
                 5.6 
                   
                   
                 1.7 
                 2898 
                 3180 
                 3313 
                 2788 
               
               
                   
                 then clears 
                   
                   
                   
                   
                 (0.005%) 
                 (0.005%) 
                 (0.005%) 
                 (0.004%) 
               
               
                   
                 up after 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 5 mins 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 60° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 5116 
                 13236 
                 59443 
                 61667456 
                 7725 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.021%) 
                 (0.096%) 
                 (99.837%) 
                 (0.013%) 
                   
                   
               
               
                   
                   
                 1 1   
                 4.565 
                 12218 
                 61038 
                 62306234 
                 8570 
                   
                   
               
               
                   
                   
                   
                 (0.007%) 
                 (0.020%) 
                 (0.098%) 
                 (99.768%) 
                 (0.014%) 
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12A-1 
               
             
            
               
                   
               
               
                 (X) Additional peaks for Solution 2A formulation at 60° C. at t = 1 month. 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 1 m extra 
                   
                   
                   
                   
                   
               
               
                 Area % 
                 peaks 
                   
                   
                   
                   
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 5.0 min 
                 5.1 min 
                 5.56 min 
                 5.9 min 
                 6.9 min 
                 7.4 min 
                 9.0 min 
               
               
                   
               
               
                 3173 (0.005%) 
                 1574 (0.003%) 
                 9340 (0.015%) 
                 8799 (0.014%) 
                 2986 (0.005%) 
                 4115 (0.007%) 
                 732 (0.001%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 13A 
               
               
                   
               
               
                 (Y) Summary of results for the Solution 3A formulation at 5° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.6 
                   
                   
                 0.9 
                 N/A 
                 2228 
                 1921 
                 879 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 N/A 
                 (0.007%) 
                 (0.006%) 
                 (0.003%) 
               
               
                 1 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 1   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 N/A 
                 2341 
                 2163 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.007%) 
                 (0.006%) 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 5° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 2539 
                 5549 
                 27041 
                 33868383 
                 27763 
                   
                   
               
               
                   
                   
                   
                 (0.007%) 
                 (0.016%) 
                 (0.080%) 
                 (99.800%) 
                 (0.082%) 
                   
                   
               
               
                   
                   
                 1 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 33243404 
                  8292 
                   
                   
               
               
                   
                   
                   
                   
                   
                   
                 (99.865%) 
                 (0.025%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14A 
               
               
                   
               
               
                 (Z) Summary of results for the Solution 3A formulation at 25° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 25° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 24.10 
                 0.60 
                 1.0 
                 978 
                 2398 
                 1865 
                 1091 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.007%) 
                 (0.005%) 
                 (0.003%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 987 
                 2880 
                 2776 
                 1286 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.008%) 
                 (0.008%) 
                 (0.004%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 N/A 
                 3139 
                 5626 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.010%) 
                 (0.018%) 
                   
               
               
                 6 1   
                 Clear and 
                 5.5 
                 36.50 
                 1.00 
                 0.9 
                 N/A 
                 2917 
                 2113 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.009%) 
                 (0.006%) 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 25° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 1958 
                 5624 
                 28586 
                 34141239 
                 13128 
                   
                   
               
               
                   
                   
                   
                 (0.006%) 
                 (0.016%) 
                 (0.094%) 
                 (99.837%) 
                 (0.038%) 
                   
                   
               
               
                   
                   
                 1 1   
                 2786 
                 7128 
                 29003 
                 33940156 
                  7013 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.021%) 
                 (0.085%) 
                 (99.829%) 
                 (0.021%) 
                   
                   
               
               
                   
                   
                 3 2   
                 2484 
                 4551 
                 32787 
                 30862935 
                 21336 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.015%) 
                 (0.106%) 
                 (99.646%) 
                 (0.069%) 
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 33384663 
                  3199 
                   
                   
               
               
                   
                   
                   
                   
                   
                   
                 (99.881%) 
                 (0.010%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14A-1 
               
             
            
               
                   
               
               
                 (AA) 
               
               
                 Additional peaks for Solution 3A formulation 
               
               
                 at 25° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                 HPLC Purity, 
                 T = 1 m extra 
                   
               
               
                 Area % 
                 peaks 
                 Peak @ 39.8 
               
               
                 Peak @ 4.4 min 
                 Peak @ 5.0 min 
                 min 
               
               
                   
               
               
                 987 (0.003%) 
                 3934 (0.012%) 
                 244 (0.001%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14A-2 
               
             
            
               
                   
               
               
                 (BB) Additional peaks for Solution 3A  
               
               
                 formulation at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m extra 
                   
               
               
                 Area % 
                 peaks 
               
               
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 7.9 min 
                 15.3 min 
                 36.8 min 
               
               
                 14151 
                 6463 
                 6734 
               
               
                 (0.046%) 
                 (0.021%) 
                 (0.022%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15A 
               
               
                   
               
               
                 (CC) Summary of results for the Solution 3A formulation at 40° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 22.00 
                 1.00 
                 0.9 
                 855 
                 2876 
                 2098 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.008%) 
                 (0.006%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 730 
                 2941 
                 1604 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.009%) 
                 (0.005%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                 6789  
                 5125 
                 13881 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.023%) 
                 (0.017%) 
                 (0.045%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 57.90 
                 1.50 
                 0.9 
                 N/A 
                 8800 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.026%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 40° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 1006  
                 2701 
                 7437 
                 29878 
                 34007216 
                 7294 
               
               
                   
                   
                 (0.003%) 
                 (0.008%) 
                 (0.022%) 
                 (0.088%) 
                 (99.841%) 
                 (0.080%) 
               
               
                   
                 1 1   
                 931 
                 1592 
                 5306 
                 29304 
                 33926903 
                 10987  
               
               
                   
                   
                 (0.003%) 
                 (0.005%) 
                 (0.016%) 
                 (0.086%) 
                 (99.839%) 
                 (0.032%) 
               
               
                   
                 3 2   
                 N/A 
                 2261 
                 5441 
                 31138 
                 30598360 
                 21509  
               
               
                   
                   
                   
                 (0.007%) 
                 (0.018%) 
                 (0.101%) 
                 (99.561%) 
                 (0.058%) 
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 26116 
                 33379272 
                 6201 
               
               
                   
                   
                   
                   
                   
                 (0.078%) 
                 (99.791%) 
                 (0.019%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15A-1 
               
             
            
               
                   
               
               
                 (DD) Additional peaks for Solution 3A  
               
               
                 formulation at 40° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 1 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 3.1 min 
                 — 
               
               
                   
                 1365 (0.004%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15A-2 
               
             
            
               
                   
               
               
                 (EE) Additional peaks for Solution 3A formulation at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m extra 
                   
                   
                   
                   
               
               
                 Area % 
                 peaks 
               
               
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 4.8 min 
                 5.7 min 
                 7.2 min 
                 8.1 min 
                 16.7 min 
                 36.8 min 
               
               
                 7856 (0.023%) 
                 2711 (0.008%) 
                 2788 (0.008%) 
                 3786 (0.012%) 
                 4299 (0.014%) 
                 6734 (0.022%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15A-3 
               
             
            
               
                   
               
               
                 (FF) Additional peaks for Solution 3A  
               
               
                 formulation at 40° C. at t = 6 months. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 6 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 5.7 min 
                 — 
               
               
                   
                 4261 (0.013%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 16A 
               
               
                   
               
               
                 (GG) Summary of results for the Solution 3A formulation at 60° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 60° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 0.9 
                  960 
                 3048 
                 2309 
                 1379 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.009%) 
                 (0.007%) 
                 (0.004%) 
               
               
                 1 1   
                 Clear, 
                 5.6 
                   
                   
                 0.9 
                 2403 
                 3683 
                 N/A 
                 1961 
               
               
                   
                 then clears 
                   
                   
                   
                   
                 (0.007%) 
                 (0.011%) 
                   
                 (0.006%) 
               
               
                   
                 up after 5 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 min 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 60° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 1731 
                 5375 
                 29049 
                 33529633 
                  7715 
                   
                   
               
               
                   
                   
                   
                 (0.005%) 
                 (0.016%) 
                 (0.087%) 
                 (99.846%) 
                 (0.023%) 
                   
                   
               
               
                   
                   
                 1 1   
                 1447 
                 3041 
                 29174 
                 33932823 
                 10919 
                   
                   
               
               
                   
                   
                   
                 (0.004%) 
                 (0.009%) 
                 (0.085%) 
                 (99.249%) 
                 (0.032%) 
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 16A-1 
               
             
            
               
                   
               
               
                 (HH) Additional peaks for Solution 3A formulation at 60° C. at t = 1 month. 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 1 m extra 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Area % 
                 peaks 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 3.1 min 
                 3.9 min 
                 5.1 min 
                 5.56 min 
                 5.9 min 
                 6.9 min 
                 7.4 min 
                 9.0 min 
                 25.7 min 
               
               
                   
               
               
                 163418  
                 2403 
                 1016 
                 7846 
                 5022 
                 2962 
                 3107 
                 3314 
                 14985 
               
               
                 (0.478%) 
                 (0.007%) 
                 (0.003%) 
                 (0.023%) 
                 (0.015%) 
                 (0.009%) 
                 (0.009%) 
                 (0.010%) 
                 (0.044%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 17A 
               
               
                   
               
               
                 (II) Summary of results for the Solution 3P formulation at 5° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 609 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (100%) 
                   
                   
                   
               
               
                 1 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 1   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 5° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                   
                   
               
               
                   
                   
                 1 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                   
                   
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 18A 
               
               
                   
               
               
                 (JJ) Summary of results for the Solution 3P formulation at 25° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 3P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 18.90 
                 1.20 
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 636 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (100%) 
                   
                   
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 N/A 
                 N/A 
                 11254 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                 (22.927%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 42.90 
                 2.20 
                 0 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 40° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 1 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 3 2   
                 N/A 
                 N/A 
                 N/A 
                 20892 
                 N/A 
                 16940 
               
               
                   
                   
                   
                   
                   
                 (42.562%) 
                   
                 (34.511%) 
               
               
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 19A 
               
               
                   
               
               
                 (KK) Summary of results for the Solution 3P formulation at 40° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 17.10 
                 0.80 
                 0 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 1594 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (51.041%) 
                   
                   
                   
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 N/A 
                 N/A 
                 9421 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                 (12.884%) 
                   
               
               
                 6 1   
                 Clear and 
                 5.5 
                 49.50 
                 1.7 
                 0 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 40° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                   
                   
               
               
                   
                   
                 1 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                   
                   
               
               
                   
                   
                 3 2   
                 N/A 
                 N/A 
                 22140 
                 N/A 
                 25435 
                   
                   
               
               
                   
                   
                   
                   
                   
                 (30.279%) 
                   
                 (34.785%) 
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                  4955 
                   
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 (11.855%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 19A-1 
               
             
            
               
                   
               
               
                 (LL) Additional peaks for Solution 3P 
               
               
                 formulation at 40° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 1 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 3.1 min 
                 — 
               
               
                   
                 1529 (48.959%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 19A-2 
               
             
            
               
                   
               
               
                 (MM) Additional peaks for Solution 3P  
               
               
                 formulation at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 3 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 22.8 min 
                 — 
               
               
                   
                 14492 (19.819%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 19A-3 
               
             
            
               
                   
               
               
                 (NN) Additional peaks for Solution 3P  
               
               
                 formulation at 40° C. at t = 6 months. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 6 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 33.8 mm 
                 — 
               
               
                   
                 3722 (8.905%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 20A 
               
               
                   
               
               
                 (OO) Summary of results for the Solution 3P formulation at 60° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3P 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 60° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 1 1   
                 Cloudy, 
                 5.5 
                   
                   
                 0 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
               
               
                   
                 then clears 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 up after 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                 5 min 
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 60° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                   
                   
               
               
                   
                   
                 1 1   
                 N/A 
                 N/A 
                 N/A 
                 N/A 
                 10919 
                   
                   
               
               
                   
                   
                   
                   
                   
                   
                   
                 (0.032%) 
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 20A-1 
               
             
            
               
                   
               
               
                 (PP) Additional peaks for Solution 3P  
               
               
                 formulation at 60° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 6 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 3.1 min 
                 — 
               
               
                   
                 190906 
                 — 
               
               
                   
                 (93.021%) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 21A 
               
               
                   
               
               
                 (QQ) Summary of results for the Solution 4A formulation at 5° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 5° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 1436 
                 4012 
                 4102 
                 2436 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.006%) 
                 (0.007%) 
                 (0.004%) 
               
               
                 1 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 N/A 
                 4220 
                 5189 
                 1915 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.007%) 
                 (0.009%) 
                 (0.003%) 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 5° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 5104 
                 13313 
                 61130 
                 61955043 
                 25823 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.021%) 
                 (0.098%) 
                 (99.811%) 
                 (0.042%) 
                   
                   
               
               
                   
                   
                 1 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 59398 
                 59297216 
                  7233 
                   
                   
               
               
                   
                   
                   
                   
                   
                 (0.100%) 
                 (99.829%) 
                 (0.012%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 22A 
               
               
                   
               
               
                 (RR) Summary of results for the Solution 4A formulation at 25° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 25° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                 19.60 
                 0.80 
                 1.7 
                 1609 
                 4274 
                 4316 
                 2568 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.003%) 
                 (0.007%) 
                 (0.007%) 
                 (0.004%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 2691 
                 4756 
                 5615 
                 2490 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.009%) 
                 (0.004%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 1.6 
                 2867 
                 5164 
                 11833  
                 3338 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.004%) 
                 (0.010%) 
                 (0.025%) 
                 (0.005%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 31.80 
                 2.90 
                 1.7 
                 N/A 
                 4892 
                 6113 
                 2011 
               
               
                   
                 colorless 
                   
                   
                   
                   
                   
                 (0.008%) 
                 (0.010%) 
                 (0.003%) 
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 25° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 4916 
                 13545 
                 62372 
                 62035143 
                  8603 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.022%) 
                 (0.100%) 
                 (99.836%) 
                 (0.014%) 
                   
                   
               
               
                   
                   
                 1 1   
                 4918 
                 12873 
                 61607 
                 61851541 
                 18960 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.021%) 
                 (0.099%) 
                 (99.813%) 
                 (0.031%) 
                   
                   
               
               
                   
                   
                 3 2   
                 5333 
                  9917 
                 62318 
                 5339537 
                 24904 
                   
                   
               
               
                   
                   
                   
                 (0.010%) 
                 (0.019%) 
                 (0.116%) 
                 (99.667%) 
                 (0.046%) 
                   
                   
               
               
                   
                   
                 6 1   
                 N/A 
                 N/A 
                 54274 
                 59415139 
                  5796 
                   
                   
               
               
                   
                   
                   
                   
                   
                 (0.091%) 
                 (99.836%) 
                 (0.010%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 22A-1 
               
             
            
               
                   
               
               
                 (SS) Additional peaks for Solution 4A 
               
               
                 formulation at 25° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 1 m extra 
               
               
                   
                 Area @ 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 36.6 min 
                 — 
               
               
                   
                 880 (0.001%) 
                 — 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 22A-2 
               
             
            
               
                   
               
               
                 (TT) Additional peaks for Solution 4A formulation 
               
               
                 at 25° C. at t = 3 months. 
               
            
           
           
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m extra 
                   
                   
                   
               
               
                 Area % 
                 peaks 
               
               
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 7.2 min 
                 7.9 min  
                 8.8 min 
                 15.3 min 
                 36.8 min 
               
               
                 2566  
                 13469  
                 3338  
                 13647  
                 11556  
               
               
                 (0.004%) 
                 (0.025%) 
                 (0.005%) 
                 (0.025%) 
                 (0.022%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23A 
               
               
                   
               
               
                 (UU) Summary of results for the Solution 4A formulation at 40° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
               
               
                 40° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm 
                 25.000 μm 
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.6 
                 73.00 
                 14.00 
                 1.7 
                 1396 
                 4399 
                 4249 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.007%) 
                 (0.007%) 
               
               
                 1 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 1444 
                 6005 
                 5383 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.010%) 
                 (0.009%) 
               
               
                 3 2   
                 Clear and 
                 5.5 
                   
                   
                 1.6 
                 9735 
                 8725 
                 12070  
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.018%) 
                 (0.016%) 
                 (0.023%) 
               
               
                 6 1   
                 Clear and 
                 5.5 
                 64.10 
                 3.40 
                 1.7 
                 2344 
                 16305  
                 3594 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.004%) 
                 (0.027%) 
                 (0.006%) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
            
               
                   
                 Testing time, 
                   
                   
                   
                   
                   
                   
               
               
                   
                 40° C. 
                 Peak 4, 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
               
               
                   
                 (months) 
                 9.1 min 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                 0 1   
                 2491 
                 5032 
                 13525 
                 60955 
                 61808714 
                 4932 
               
               
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.022%) 
                 (0.098%) 
                 (99.843%) 
                 (0.008%) 
               
               
                   
                 1 1   
                 2371 
                 4766 
                 14950 
                 64181 
                 61911629 
                 12508  
               
               
                   
                   
                 (0.004%) 
                 (0.008%) 
                 (0.024%) 
                 (0.103%) 
                 (99.814%) 
                 (0.020%) 
               
               
                   
                 3 2   
                 3279 
                 5247 
                 13313 
                 60741 
                 53343311 
                 30494  
               
               
                   
                   
                 (0.005%) 
                 (0.010%) 
                 (0.025%) 
                 (0.113%) 
                 (99.557%) 
                 (0.057%) 
               
               
                   
                 6 1   
                 3534 
                 N/A 
                 N/A 
                 26386 
                 59466240 
                 5071 
               
               
                   
                   
                 (0.006%) 
                   
                   
                 (0.044%) 
                 (99.792%) 
                 (0.009%) 
               
               
                   
               
               
                   1 Performed on HPLC10 
               
               
                   2 Performed on HPLC12 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23A-1 
               
             
            
               
                   
               
               
                 (VV) Additional peaks for Solution 4A  
               
               
                 formulation at 40° C. at t = 1 month. 
               
            
           
           
               
               
               
            
               
                   
                 HPLC Purity, 
                 T = 1 m extra 
               
               
                   
                 Area % 
                 peaks 
               
               
                   
                   
               
               
                   
                 Peak @ 5.9 min 
                 Peak @ 36.6 min 
               
               
                   
                 1982 (0.003%) 
                 1001 (0.002%) 
               
               
                   
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23A-2 
               
             
            
               
                   
               
               
                 (WW) Additional peaks for Solution 4A formulation at 40° C. at t = 3 months. 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 3 m extra 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Area % 
                 peaks 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 4.8 min 
                 4.9 min 
                 5.5 min 
                 5.7 min 
                 6.7 min 
                 7.2 min 
                 7.9 min 
                 16.7 min 
                 38.3 min 
               
               
                   
               
               
                 5243  
                 2166 
                 2835 
                 5989 
                 3727 
                 10449 
                 18748 
                 9702 
                 7206 
               
               
                 (0.009%) 
                 (0.004%) 
                 (0.005%) 
                 (0.011%) 
                 (0.007%) 
                 (0.019%) 
                 (0.035%) 
                 (0.018%) 
                 (0.014%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 23A-3 
               
             
            
               
                   
               
               
                 (XX) Additional peaks for Solution 4A  
               
               
                 formulation at 40° C. at t = 6 months. 
               
            
           
           
               
               
               
            
               
                 HPLC Purity, 
                 T = 6 m extra 
                   
               
               
                 Area % 
                 peaks 
               
               
                   
               
               
                 Peak @ 5.7 min 
                 Peak @ 33.9 min 
                 Peak @ 39.8 min 
               
               
                 9446 (0.016%) 
                 2487 (0.004%) 
                 2507 (0.004%) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 24A 
               
               
                   
               
               
                 (YY) Summary of results for the Solution 4A formulation at 60° C. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                 Average 
                 Average 
                   
                 HPLC 
                   
                   
                   
               
               
                 Testing 
                   
                   
                 Particles 
                 Particles 
                   
                 Purity, 
                   
                   
                   
               
               
                 time, 
                 Solution 3A 
                   
                 Per 
                 Per 
                 Conc., 
                 Area % 
                   
                   
                   
               
               
                 60° C. 
                 Attribute 
                   
                 Container 
                 Container 
                 HPLC 
                 Peak 1, 
                 Peak 2, 
                 Peak 3, 
                 Peak 4, 
               
               
                 (months) 
                 Appearance 
                 pH 
                 10.000 μm  
                 25.000 μm  
                 (mg/ml) 
                 4.4 min 
                 5.6 min 
                 8.4 min 
                 9.1 min 
               
               
                   
               
               
                 0 1   
                 Clear and 
                 5.5 
                   
                   
                 1.7 
                 1381 
                 4731 
                 4848 
                 2488 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.002%) 
                 (0.008%) 
                 (0.008%) 
                 (0.004%) 
               
               
                 1 1   
                 Clear and 
                 5.6 
                   
                   
                 1.7 
                 6290 
                 9546 
                 1982 
                 4376 
               
               
                   
                 colorless 
                   
                   
                   
                   
                 (0.010%) 
                 (0.015%) 
                 (0.003%) 
                 (0.007%) 
               
               
                 3 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                 6 
                   
                   
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   
                   
                 Testing 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 time, 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 60° C. 
                 Peak 5, 
                 Peak 6, 
                 Peak 7, 
                 Capsaicin 
                 Peak 8, 
                   
                   
               
               
                   
                   
                 (months) 
                 13.6 min 
                 16.8 min 
                 20.5 min 
                 20.9 min 
                 37.7 min 
               
               
                   
               
               
                   
                   
                 0 1   
                 5365 
                 12924 
                 60663 
                 61567424 
                  8644 
                   
                   
               
               
                   
                   
                   
                 (0.009%) 
                 (0.021%) 
                 (0.098%) 
                 (99.828%) 
                 (0.014%) 
                   
                   
               
               
                   
                   
                 1 1   
                 4675 
                  9876 
                 61931 
                 61706951 
                 11857 
                   
                   
               
               
                   
                   
                   
                 (0.008%) 
                 (0.016%) 
                 (0.100%) 
                 (99.391%) 
                 (0.019%) 
                   
                   
               
               
                   
                   
                 3 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
                   
                 6 
                   
                   
                   
                   
                   
                   
                   
               
               
                   
               
               
                   1 Performed on HPLC10 
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 24A-1 
               
               
                   
               
               
                 (ZZ) Additional peaks for Solution 4A formulation at 60° C. at t = 1 month. 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 HPLC Purity, 
                 T = 1 m  
                   
                   
                   
                   
                   
                   
                   
               
               
                 Area % 
                 extra peaks 
                   
                   
                   
                   
                   
                   
                   
               
               
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
               
               
                 3.1 min 
                 3.9 min 
                 5.0 min 
                 5.1 min 
                 5.56 min 
                 5.9 min 
                 6.9 min 
                 7.4 min 
                 9.0 min 
               
               
                   
               
               
                 158505  
                 5348 
                 6645 
                 5154 
                 15935 
                 11537 
                 7720 
                 8282 
                 6672 
               
               
                 (0.255%) 
                 (0.009%) 
                 (0.011%) 
                 (0.008%) 
                 (0.026%) 
                 (0.019%) 
                 (0.012%) 
                 (0.013%) 
                 (0.011%) 
               
               
                   
               
               
                   
                   
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                 Peak @  
                   
                   
               
               
                   
                   
                 18.8 min 
                 25.7 min 
                 34.3 min 
                 36.6 min 
                 39.8 min 
               
               
                   
               
               
                   
                   
                 9415 
                 21701 
                 3589 
                 808 
                 5264 
                   
                   
               
               
                   
                   
                 (0.015%) 
                 (0.035%) 
                 (0.006%) 
                 (0.001%) 
                 (0.008%) 
               
               
                   
               
            
           
         
       
     
     Example 3—Preparation of Additional Exemplary Capsaicin Aqueous Formulations 
     Three additional exemplary stable aqueous capsaicin injectable formulations were prepared. Experimental procedures and results are provided below. 
     Part I—Preparation of First Exemplary Additional Formulation 
     The formulation listed in the table below was prepared by the following procedure:
         (a) Place 900 mL of water in a vessel;   (b) Add 6.80 grams of sodium acetate to the vessel containing water;   (c) Adjust solution pH to 5.5 by adding 1N HCl;   (d) Add 10.0 grams of Kolliphor HS 15 to the solution [the Kolliphor HS 15 has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of       

     
       
         
         
             
             
         
       
         
         
           
              and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15]; 
             (e) Add 0.10 grams of dibutylhydroxytoluene to the solution, and let the solution age for at least 2 hours; 
             (f) Add 0.25 grams of ethylenediaminetetraacetic acid tetrasodium salt to the solution; 
             (g) Add 0.50 grams of trans-capsaicin to the solution, and age the solution until the trans-capsaicin dissolves; 
             (h) Add 6.0 grams of NaCl to the solution; 
             (i) Adjust pH of the solution to pH=5.5 by adding 1N HCl or 1N NaOH as needed; 
             (j) q.s. with water so the volume of the solution reaches 1 liter; and 
             (k) Sterile filter the solution. 
           
         
       
    
     
       
         
           
               
             
               
                   
               
               
                 Formulation 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                  a. 0.05% (w/w) of trans-capsaicin; 
               
               
                  b. 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   a mixture of 
               
               
                                    
 
               
               
                   
               
               
                                    
 
               
               
                   
               
               
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   weight average molecular weight of about 660 g/mol; 
               
               
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                  d. 0.68% (w/w) of sodium acetate or a mixture of sodium acetate and 
               
               
                   acetic acid; 
               
               
                  e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                  f. 0.6% (w/w) of sodium chloride; 
               
               
                  g. q.s. with water (i.e., least 97.6% (w/w)); and 
               
               
                 having a pH of 5.5. 
               
               
                   
               
            
           
         
       
     
     Part II—Preparation of Second Exemplary Additional Formulation 
     The formulation listed in the table below was prepared by the following procedure:
         (a) Place 900 mL of water in a vessel;   (b) Add 3.40 grams of sodium acetate to the vessel containing water;   (c) Adjust solution pH to 5.5 by adding 1N HCl;   (d) Add 10.0 grams of Kolliphor HS 15 to the solution [the Kolliphor HS 15 has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of       

     
       
         
         
             
             
         
       
         
         
           
              and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15]; 
             (e) Add 0.10 grams of dibutylhydroxytoluene to the solution, and let the solution age for at least 2 hours; 
             (f) Add 0.25 grams of ethylenediaminetetraacetic acid tetrasodium salt to the solution; 
             (g) Add 0.50 grams of trans-capsaicin to the solution, and age the solution until the trans-capsaicin dissolves; 
             (h) Add 7.5 grams of NaCl to the solution; 
             (i) Adjust pH of the solution to pH=5.5 by adding 1N HCl or 1N NaOH as needed; 
             (j) q.s. with water so the volume of the solution reaches 1 liter; and 
             (k) Sterile filter the solution. 
           
         
       
    
     
       
         
           
               
             
               
                   
               
               
                 Formulation 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                  a. 0.05% (w/w) of trans-capsaicin; 
               
               
                  b. 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   a mixture of 
               
               
                   
               
               
                                    
 
               
               
                   
               
               
                                    
 
               
               
                   
               
               
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   weight average molecular weight of about 660 g/mol; 
               
               
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                  d. 0.34% (w/w) of sodium acetate or a mixture of sodium acetate and 
               
               
                   acetic acid; 
               
               
                  e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                  f. 0.75% (w/w) of sodium chloride; 
               
               
                  g. q.s. with water (i.e., least 97.8% (w/w)); and 
               
               
                 having a pH of 5.5. 
               
               
                   
               
            
           
         
       
     
     Part III—Preparation of Third Exemplary Additional Formulation 
     The formulation listed in the table below was prepared by the following procedure:
         (a) Place 900 mL of water in a vessel;   (b) Add 2.2 grams of trisodium citrate dihydrate to the vessel containing water;   (c) Adjust solution pH to 5.5 by adding 1N HCl;   (d) Add 10.0 grams of Kolliphor HS 15 to the solution [the Kolliphor HS 15 has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of       

     
       
         
         
             
             
         
       
         
         
           
              and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15]; 
             (e) Add 0.10 grams of dibutylhydroxytoluene to the solution, and let the solution age for at least 2 hours; 
             (f) Add 0.25 grams of ethylenediaminetetraacetic acid tetrasodium salt to the solution; 
             (g) Add 0.50 grams of trans-capsaicin to the solution, and age the solution until the trans-capsaicin dissolves; 
             (h) Add 8.0 grams of NaCl to the solution; 
             (i) Adjust pH of the solution to pH=5.5 by adding 1N HCl or 1N NaOH as needed; 
             (j) q.s. with water so the volume of the solution reaches 1 liter; and 
             (k) Sterile filter the solution. 
           
         
       
    
     
       
         
           
               
             
               
                   
               
               
                 Formulation 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 An aqueous, capsaicin injectable formulation, comprising: 
               
               
                  a. 0.05% (w/w) of trans-capsaicin; 
               
               
                  b. 1% (w/w) of a solubilizing agent, wherein the solubilizing agent is 
               
               
                   a mixture of 
               
               
                   
               
               
                                    
 
               
               
                   
               
               
                                    
 
               
               
                   
               
               
                   and polyethylene glycol; wherein the polyethylene glycolyl has a 
               
               
                   weight average molecular weight of about 660 g/mol; 
               
               
                  c. 0.01% (w/w) dibutylhydroxytoluene; 
               
               
                  d. 0.22% (w/w) of sodium citrate or a mixture of sodium citrate and 
               
               
                   citric acid; 
               
               
                  e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                  f. 0.8% (w/w) of sodium chloride; 
               
               
                  g. q.s. with water (i.e., 97.9% (w/w) water); and 
               
               
                 having a pH of 5.5. 
               
               
                   
               
            
           
         
       
     
     Example 4—Analysis of Capsaicin Solubility in Multiple Aqueous Formulations Containing a Solubilizing Agent 
     Multiple aqueous formulations were prepared and analyzed to determine the amount of dissolved capsaicin. The formulations contained differing amounts of the solubilizing agent Kolliphor HS 15 to increase the amount of capsaicin dissolved in the aqueous medium. The experimental procedures and results are described below. 
     Experimental Procedures 
     The equilibrium solubility of capsaicin was determined in a series of aqueous solutions. Eight different solutions were prepared, as described in Table 10 below, and the amount of dissolved capsaicin was determined. All eight solutions had a pH of 5.5. Kolliphor HS 15 has CAS Registry No. 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 10 
               
               
                   
               
               
                   
                 Amount of 
                 Observed  
                   
               
               
                   
                 Kolliphor 
                 Dissolved 
                   
               
               
                   
                 HS 15 
                 Capsaicin 
                   
               
               
                 No. 
                 (w/v) 
                 (mg/mL) 
                 Other Components (w/v) 
               
               
                   
               
             
            
               
                 1 
                 1% 
                 0.958 
                 0.9% NaCl, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 2 
                 2% 
                 1.68 
                 0.9% NaCl, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 3 
                 4% 
                 2.47 
                 0.9% NaCl, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 4 
                 5% 
                 3.76 
                 0.9% NaCl, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 5 
                 1% 
                 1.05 
                 5% Dextrose, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 6 
                 2% 
                 1.70 
                 5% Dextrose, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 7 
                 4% 
                 2.67 
                 5% Dextrose, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                 8 
                 5% 
                 3.78 
                 5% Dextrose, 0.1% EDTA, 0.01% 
               
               
                   
                   
                   
                 butylated hydroxytoluene, and 20 
               
               
                   
                   
                   
                 mM Citrate Buffer. 
               
               
                   
               
            
           
         
       
     
     Example 5—Twenty-Six Month Stability Analysis for Exemplary Formulations 
     The formulations in Table 11 below were subjected to stability analysis by storage for twenty-six (26) months at the conditions specified below (i.e., 25° C. at 60% relative humidity, or 40° C. at 75% relative humidity), followed by analytical analysis to determine the amount of trans-capsaicin and any detectable impurities in the formulation. Results are presented in Tables 12-15 below. 
     The abbreviation BHT refers to dibutylhydroxytoluene. The abbreviation “EDTA” refers to ethylenediaminetetraacetic acid. The abbreviation “ND” refers to not detected. The Kolliphor HS-15 has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15. The phrase “Average Particles Per Container” refers to the average number of particles observed in a container, where the container held approximately 1.5 mL of aqueous formulation to be analyzed.
 
Dimer 1 Impurity has the following chemical structure:
 
     
       
         
         
             
             
         
       
     
     Dimer 2 Impurity is believed to have one of the following chemical structures: 
     
       
         
         
             
             
         
       
     
     5-Oxo-capsaicin has the following chemical structure: 
     
       
         
         
             
             
         
       
     
     
       
         
           
               
               
             
               
                 TABLE 11 
               
               
                   
               
               
                 Formulation 1A 
                 Formulation 2A 
               
               
                   
               
             
            
               
                 1 mg/mL trans-capsaicin 
                 2 mg/mL trans-capsaicin 
               
               
                 2% (wt/wt) Kolliphor HS-15 
                 4% (wt/wt) Kolliphor HS-15 
               
               
                 20 mM citrate buffer 
                 20 mM citrate buffer 
               
               
                 0.1% (wt/wt) disodium EDTA 
                 0.1% (wt/wt) disodium EDTA 
               
               
                 0.01% (wt/wt) BHT 
                 0.01% (wt/wt) BHT 
               
               
                 0.625% (wt/wt) NaCl 
                 0.625% (wt/wt) NaCl 
               
               
                 q.s. water 
                 q.s. water 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 12 
               
               
                   
               
               
                 Summary of Results from Storage of Formulation 1A for 26 
               
               
                 Months at 25° C./60% Relative Humidity 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Observed Result 
                 Observed Result 
               
               
                   
                 at Time = 
                 at Time = 
               
               
                 Analytical Feature 
                 0 Months 
                 26 Months 
               
               
                   
               
               
                 Appearance 
                 clear and  
                 clear and  
               
               
                   
                 colorless 
                 colorless 
               
               
                 pH of the solution 
                 5.5 
                 5.35 
               
               
                 Average Number of Particles 
                 19.4 
                 583 
               
               
                 Having Size ≥10 μM Per Container 
                   
                   
               
               
                 Average Number of Particles 
                 1.1 
                 235 
               
               
                 Having Size ≥25 μM Per Container 
                   
                   
               
               
                 Concentration of trans-capsaicin 
                 1.0 
                 0.99 
               
               
                 (mg/mL) as determined by HPLC 
                   
                   
               
               
                 analysis 
                   
                   
               
               
                 Concentration of BHT (mg/mL) 
                 Not tested 
                 0.0108 
               
               
                   
               
            
           
           
               
            
               
                 Purity Analysis by HPLC 
               
            
           
           
               
               
            
               
                   
                 Detected Amount According to  
               
               
                 Analyte 
                 Percent Area of HPLC Plot (area %) 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Impurity at RRT 0.27 in HPLC 
                 0.01 
                 ND 
               
               
                 Plot 
                   
                   
               
               
                 5-oxo-capsaicin 
                 0.01 
                 0.06 
               
               
                 Impurity at RRT 0.80 in HPLC 
                 0.02 
                 0.06 
               
               
                 Plot 
                   
                   
               
               
                 cis-capsaicin 
                 0.01 
                 0.08 
               
               
                 trans-capsaicin 
                 99.80 
                 99.8 
               
               
                 Dimer 1 Impurity 
                 0.02 
                 ND 
               
               
                 Dimer 2 Impurity 
                 ND 
                 ND 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 13 
               
               
                   
               
               
                 Summary of Results from Storage of Formulation 1A for 26 
               
               
                 Months at 40° C./75% Relative Humidity 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Observed Result at 
                 Observed Result at 
               
               
                 Analytical Feature 
                 Time = 0 Months 
                 Time = 26 Months 
               
               
                   
               
               
                 Appearance 
                 clear and  
                 slightly opaque, no 
               
               
                   
                 colorless 
                 visible particles 
               
               
                 pH of the solution 
                 5.5 
                 5.40 
               
               
                 Average Number of Particles 
                 45.8 
                 583 
               
               
                 Having Size ≥ 10 μM Per Container 
                   
                   
               
               
                 Average Number of Particles 
                 2.0 
                 235 
               
               
                 Having Size ≥ 25 μM Per Container 
                   
                   
               
               
                 Concentration of trans-capsaicin 
                 1.0 
                 1.0 
               
               
                 (mg/mL) as determined by HPLC 
                   
                   
               
               
                 analysis 
                   
                   
               
               
                 Concentration of BHT (mg/mL) 
                 Not tested 
                 0.0108 
               
               
                   
               
            
           
           
               
            
               
                 Purity Analysis by HPLC 
               
            
           
           
               
               
            
               
                   
                 Detected Amount According to Percent 
               
               
                 Analyte 
                 Area of HPLC Plot (area %) 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Impurity at RRT 0.27 in HPLC Plot 
                 0.01 
                 ND 
               
               
                 5-oxo-capsaicin 
                 0.01 
                 0.06 
               
               
                 Impurity at RRT 0.80 in HPLC Plot 
                 0.02 
                 0.06 
               
               
                 cis-capsaicin 
                 0.01 
                 0.09 
               
               
                 trans-capsaicin 
                 99.80 
                 99.75 
               
               
                 Dimer 1 Impurity 
                 0.02 
                 0.02 
               
               
                 Dimer 2 Impurity 
                 ND 
                 0.01 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 14 
               
               
                   
               
               
                 Summary of Results from Storage of Formulation 2A for 26 
               
               
                 Months at 25° C./60% Relative Humidity 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Observed Result 
                 Observed Result 
               
               
                   
                 at Time = 
                 at Time = 
               
               
                 Analytical Feature 
                 0 Months 
                 26 Months 
               
               
                   
               
               
                 Appearance 
                 clear and 
                 clear and 
               
               
                   
                 colorless 
                 colorless 
               
               
                 pH of the solution 
                 5.6 
                 5.41 
               
               
                 Average Number of Particles 
                 16.6 
                 759 
               
               
                 Having Size ≥10 μM Per Container 
                   
                   
               
               
                 Average Number of Particles 
                 0.4 
                 611 
               
               
                 Having Size ≥25 μM Per Container 
                   
                   
               
               
                 Concentration of trans-capsaicin 
                 1.7 
                 1.7 
               
               
                 (mg/mL) as determined by HPLC 
                   
                   
               
               
                 analysis 
                   
                   
               
               
                 Concentration of BHT (mg/mL) 
                 Not tested 
                 0.010 
               
               
                   
               
            
           
           
               
            
               
                 Purity Analysis by HPLC 
               
            
           
           
               
               
            
               
                   
                 Detected Amount According to 
               
               
                 Analyte 
                 Percent Area of HPLC Plot (area %) 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Impurity at RRT 0.27 in HPLC 
                 0.01 
                 ND 
               
               
                 Plot 
                   
                   
               
               
                 5-oxo-capsaicin 
                 0.01 
                 0.04 
               
               
                 Impurity at RRT 0.80 in HPLC 
                 0.02 
                 0.07 
               
               
                 Plot 
                   
                   
               
               
                 cis-capsaicin 
                 0.10 
                 0.09 
               
               
                 trans-capsaicin 
                 99.82 
                 99.79 
               
               
                 Dimer 1 Impurity 
                 0.003 
                 0.01 
               
               
                 Dimer 2 Impurity 
                 ND 
                 ND 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 15 
               
               
                   
               
               
                 Summary of Results from Storage of Formulation 2A for 26 
               
               
                 Months at 40° C./75% Relative Humidity 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                   
                 Observed Result at 
                 Observed Result at 
               
               
                 Analytical Feature 
                 Time = 0 Months 
                 Time = 26 Months 
               
               
                   
               
               
                 Appearance 
                 clear and colorless 
                 Slightly opaque, no 
               
               
                 visible particles 
                   
                   
               
               
                 pH of the solution 
                 5.6 
                 5.40 
               
               
                 Average Number of Particles 
                 10.9 
                 3471 
               
               
                 Having Size ≥10 μM Per Container 
                   
                   
               
               
                 Average Number of Particles 
                 0.8 
                 458 
               
               
                 Having Size ≥25 μM Per Container 
                   
                   
               
               
                 Concentration of trans-capsaicin 
                 1.7 
                 1.7 
               
               
                 (mg/mL) as determined by HPLC 
                   
                   
               
               
                 analysis 
                   
                   
               
               
                 Concentration of BHT (mg/mL) 
                 Not tested 
                 0.010 
               
               
                   
               
            
           
           
               
            
               
                 Purity Analysis by HPLC 
               
            
           
           
               
               
            
               
                   
                 Detected Amount According to  
               
               
                 Analyte 
                 Percent Area of HPLC Plot (area %) 
               
               
                   
               
            
           
           
               
               
               
            
               
                 Impurity at RRT 0.27 in HPLC Plot 
                 0.006 
                 ND 
               
               
                 5-oxo-capsaicin 
                 0.005 
                 0.03 
               
               
                 Impurity at RRT 0.80 in HPLC Plot 
                 0.018 
                 0.07 
               
               
                 cis-capsaicin 
                 0.088 
                 0.09 
               
               
                 trans-capsaicin 
                 99.83 
                 99.71 
               
               
                 Dimer 1 Impurity 
                 0.01 
                 0.08 
               
               
                 Dimer 2 Impurity 
                 ND 
                 0.02 
               
               
                   
               
            
           
         
       
     
     Example 6—Preparation of Additional Exemplary Capsaicin Aqueous Formulation 
     The aqueous capsaicin injectable formulation labeled as Capsaicin Formulation 1 in the following table was prepared. Experimental procedures are provided below. 
     
       
         
           
               
             
               
                   
               
               
                 Capsaicin Formulation 1 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
            
               
                 An aqueous, capsaicin injectable formulation containing: 
               
               
                 a. 0.05% (w/w) of trans-capsaicin; 
               
               
                 b. 1% (w/w) of macrogol 15 hydroxystearate; 
               
               
                 c. 0.01% (w/w) dibutylated hydroxytoluene; 
               
               
                 d. 50 mM of buffer that is a mixture of sodium acetate and acetic acid; 
               
               
                 e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                 f. 0.6% (w/w) of sodium chloride; 
               
               
                 g. q.s. with water (i.e., about 97.6% (w/w)); and having a pH of 5.5. 
               
               
                   
               
            
           
         
       
     
     Experimental Procedures 
     Butylated hydroxytoluene (BHT) and macrogol 15 hydroxystearate are added and slightly warmed (to facilitate melting) and then mixed until dissolved to provide a BHT/Macrogol solution. 
     In a separate container, ethylenediaminetetraacetic acid (EDTA) is dissolved in water for injection (WFI). The resulting EDTA/WFI solution is added to the BHT/Macrogol solution while mixing. To the resulting solution is added trans-capsaicin and the resulting mixture is mixed for a minimum of 4 hours until a uniform solution is achieved (hereinafter “Capsaicin Solution”). 
     In a separate container, sodium acetate trihydrate and sodium chloride are dissolved in WFI and the pH of the solution is adjusted to a pH of about 5.5. To this solution is added the necessary amount of Capsaicin Solution and the resulting solution is adjusted to weight with WFI. The pH is measured and adjusted with hydrochloric acid as necessary to achieve a pH of 5.5±0.05. The resulting solution is mixed to assure homogeneity. Then, the solution is aseptically filtered through two 0.2 micron sterilizing filters that are tested both before use and after use for integrity, to thereby provide Capsaicin Formulation 1. 
     Macrogol 15 hydroxystearate has CAS Registry No 70142-34-6, and is a mixture containing (a) about 70% (w/w) of a mixture of 
     
       
         
         
             
             
         
       
     
     and (b) about 30% (w/w) polyethylene glycol; where the polyethylene glycolyl has a weight-average molecular weight of about 660 g/mol; which is sold and marketed by BASF as KOLLIPHOR® HS 15. 
     Example 7—Assessment of Toxicity for Exemplary Capsaicin Formulation Upon Administration to Rabbits 
     An aliquot of Capsaicin Formulation A was subjected to toxicity evaluation in rabbits. Experimental Procedures and results are provided below. 
     Part I—Experimental Procedures for Toxicity Analysis in Rabbits 
     An aliquot of Capsaicin Formulation A was administered as a single dose via intraarticular injection to rabbits, and analysis was performed to check for evidence of toxicity. Capsaicin Formulation A was prepared based on procedures described above for Capsaicin Formulation 1, and a description of Capsaicin Formulation A is provided in the following table. 
                                     Capsaicin Formulation A                                            An aqueous, capsaicin injectable formulation containing:           a. 0.05% (w/w) of trans-capsaicin;           b. 1% (w/w) of macrogol 15 hydroxystearate;           c. 0.01% (w/w) dibutylated hydroxytoluene;           d. 50 mM of buffer that is a mixture sodium acetate and acetic acid;           e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof;           f. 0.6% (w/w) of sodium chloride;           g. q.s. with water (i.e., about 97.6% (w/w)); and           having a pH of 5.5.                    
Procedurally, thirteen male and fourteen female New Zealand White rabbits were received from Covance Research Products, Inc. (Denver, Pa.). Animals were acclimated to the test facility for 14 days prior to initiation. At initiation of dosing, animals were 6 to 7 months old, and body weights ranged from 3060 g to 3587 g for males and 2923 to 3527 g for females. Animals not used in the study were removed from the study room. Males were individually housed in stainless steel cages without plastic bottoms. When possible, females were pair-housed in stainless steel cages, with plastic bottoms. Animals were individually housed during the pre-dose phase (females pair-housed upon arrival), and for behavior reasons. Water was provided ad libitum. Upon receipt, animals were presented with increasing amounts of Certified Rabbit Diet #5325 (PMI NUTRITION INTERNATIONAL CERTIFIED LABDIET®) once daily during the first week following arrival until acclimated to approximately 150 g/day. Animals were maintained on approximately 150 g/day of Certified Rabbit Diet #5325 until study termination.
 
     The male and female New Zealand White rabbits were assigned to three groups, and doses of Capsaicin Formulation A were administered as indicated in the following table. 
     
       
         
           
               
               
               
               
               
               
            
               
                   
               
               
                   
                   
                   
                 Dose of trans- 
                 Dose 
                 Concentration of 
               
            
           
           
               
               
               
               
               
            
               
                   
                 No. of Animals 
                 Capsaicin 
                 Volume 
                 Capsaicin in the 
               
            
           
           
               
               
               
               
               
               
            
               
                 Group 
                 Male 
                 Female 
                 (mg) 
                 (mL) 
                 Dose (mg/mL) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 1 (control) 
                 4 
                 4 
                 0 
                 0.6 
                 0 
               
               
                 2 
                 4 
                 4 
                 0.1 
                 0.2 
                 0.5 
               
               
                 3 
                 4 
                 4 
                 0.3 
                 0.6 
                 0.5 
               
               
                   
               
            
           
         
       
     
     Animals were administered a single dose of test article (i.e., Capsaicin Formulation A, or placebo) on Day 1 via intra-articular injection into the right stifle joint. Dosing was followed by an observation period of 4 weeks. The vehicle control article (i.e., placebo) was the same as Capsaicin Formulation A except that it did not contain capsaicin. Prior to injection of test article, animals were sedated via gas anesthesia with sevoflurane. The gas was administered by designated technicians using a nose cone. Following anesthesia but prior to intra-articular injection, the injection site was prepared aseptically with three or more chlorhexidine scrubs, wiping with sterile water between each scrub. Animals were administered 1 mg/kg of midazolam and 0.6 mg/kg of meloxicam SR subcutaneously prior to gas anesthesia. A bland ophthalmic ointment was applied to both eyes, and the right stifle joint area was clipped free of hair. Animals were positioned in dorsal recumbency, with the leg held up to allow for surgical scrub. The arthrocentesis site was prepared aseptically with three chlorhexidine scrubs, wiping with sterile water between each scrub. The right stifle joint was flexed prior to positioning the joint at an approximate 90° angle with one hand. The patella was located, and the appropriate site for arthrocentesis was palpated with a sterile, gloved hand. A 25 G x ⅝ inch needle (25 G to 23 G depending on the test article) was used to enter the joint midway between the proximal aspect of the patella and the tibial tuberosity on the lateral side of the stifle joint. The needle was directed toward the intercondylar space to a depth of approximately 7 to 10 mm and the appropriate volume (up to 0.6 mL) of test article were delivered. The stifle joint was then flexed several times. Then, the animal was placed on a warm water circulating blanket, and a bland ophthalmic ointment was applied during recovery. Buprenorphine SR (0.2 mg/kg) was administered via subcutaneous (SQ) injection between the shoulder blades during recovery. The animal was monitored for pain and discomfort during recovery and was returned to its home cage after complete recovery. An Elizabethan collar was positioned on animals chewing at dose sites, when needed. Additional pain management of animals was monitored by veterinary staff. 
     Assessment of toxicity was based on mortality, clinical observations (including qualitative food consumption), body weights, physical examinations, and clinical and anatomic pathology. Blood samples were collected for toxicokinetic evaluation. In particular, blood samples (approximately 0.5 mL) were collected via a jugular vein or medial auricular ear artery of the animals on Day 1 of the dosing phase. Samples were generally collected pre-dose and approximately 15 and 30 minutes and 1, 2, 4, 8, and 24 hours post-dose. Animals were not fasted for sample collections. Blood was collected into tubes containing potassium (K2) EDTA as the anticoagulant. Samples were maintained on chilled cryoracks prior to and after centrifugation. Samples were generally centrifuged within 1 hour of collection. Plasma was harvested and placed on dry ice until stored in a freezer, set to maintain at temperature in the range of −60° C. to −80° C. Samples remained stored until shipped on dry ice to a laboratory for analysis. Plasma samples were analyzed for capsaicin content. Toxicokinetic analysis was performed, which included analysis of Cmax, dose normalized maximum concentration (DN Cmax), Tmax, area under the curve from time 0 to the time of the last measurable concentration (calculated using the linear trapezoidal rule), area under the curve from time 0 to 24 hours (calculated using the linear trapezoidal rule), and elimination half-life. On the day of dosing, cageside observations were conducted for each animal at approximately 1, 4, and 8 hours post-dose. Post-dose observation start times were based on the dosing completion time for each animal. Abnormal findings or an indication of normal were recorded. Body weights were recorded twice during the pre-dose phase and on Days 1, 8, 15, and 22 of the dosing phase. Qualitative food consumption was recorded once daily (except on day of animal arrival) during the pre-dose and dosing phases; abnormal findings were recorded. Physical examinations were conducted once during the pre-dose phase and once Week 1 of the dosing phase; animals were examined by a Veterinarian/technical staff. 
     On Day 29 of the dosing phase, all animals were anesthetized with sodium pentobarbital, exsanguinated, and necropsied. Animals were not fasted prior to terminal procedures. Terminal body weights were recorded. A macroscopic examination of the external features of the carcass; external body orifices; abdominal, thoracic, and cranial cavities; organs; and tissues was performed. Organ weights were recorded at the scheduled sacrifice. Bone marrow smears (two slides) were prepared from the femur of each animal at scheduled sacrifices. All animals survived to the scheduled necropsy 
     Synovial fluid from the knee of each animal was collected at scheduled sacrifices for cytological examination. A study-specific procedure was followed during collection of synovial fluid and was as follows. The animal was anesthetized with sodium pentobarbital and placed in dorsal recumbency. Hair was clipped if needed. The knee was wiped with isopropyl alcohol, and skin was cut away to expose the joint. The knee was positioned by a second restrainer at an approximate 90° angle, keeping the femur and tibia aligned and the knee straight. A 23 G×¾ inch×7 inch (0.6×19 mm×178 mm) needle was attached to a syringe. The synovial fluid was collected from the right femorotibial joint. The patella was located and palpated as the joint was entered midway between the proximal aspect of the patella and the tibial tuberosity on the lateral side. The needle was advanced with a slight angle in toward the intercondylar space. The syringe was pulled to approximately 2 mL when entering the capsule joint. The needle was advanced until entering into the membrane containing synovial fluid, which allowed the synovial fluid to enter the tubing. The pressure was released from the syringe to prevent pulling the sample into the syringe prior to the removal of the needle. The sample was then placed in a vial, and the tubing was cleared of the sample by using a pistol of a 50 μL pipette tip and pushing through the tubing. Samples were placed on wet ice until two synovial fluid smears were made, and the weight was then recorded. The remaining fluid was stored in a freezer, set to maintain at a temperature in the range of −60° C. to −80° C. Samples were subjected to cytological examination. 
     Part II—Results of Toxicity Analysis in Rabbits 
     No significant local or systemic adverse effects were observed attributable to administration of up to a 0.3 mg dose of trans-capsaicin by administration of Capsaicin Formulation A once on Day 1 of the dosing phase via intra-articular injection to the stifle joint of rabbits. The observed effects of administering Capsaicin Formulation A were limited to (i) mildly increased numbers of neutrophils (heterophils) and mononuclear cells in the synovial fluid of most animals administered trans-capsaicin at a dose of 0.1 mg or 0.3 mg, and (ii) minimally decreased total protein concentration, due to minimally decreased albumin concentration, in males administered trans-capsaicin at a dose of 0.3 mg, and (iii) minimally increased myxoid material in the synovium of the stifle joint, though this finding was considered nonadverse. No effects on hematology or coagulation were identified due to administration of Capsaicin Formulation A. No difference in macroscopic findings or organ weights was observed due to administration of Capsaicin Formulation A. No alteration in body weight or body weight gain was observed due to administration of Capsaicin Formulation A. No abnormalities were observed during physical examination due to administration of Capsaicin Formulation A. 
     Based on results from this experiment, the high-dose level of 0.3 mg trans-capsaicin is the no observed adverse effect level (NOAEL). At a trans-capsaicin dose level of 0.3 mg administered in the form of Capsaicin Formulation A, the Day 1 combined (males and females) mean Cmax and AUC 0-24  values for trans-capsaicin were 37.9 ng/mL and 27.8 ng·h/mL, respectively. 
     Example 8—Assessment of Toxicity for Exemplary Capsaicin Formulation Upon Administration to Dogs 
     An aliquot of Capsaicin Formulation A was subjected to toxicity evaluation in purebred beagle dogs. Experimental Procedures and results are provided below. 
     Part I—Experimental Procedures for Toxicity Analysis in Purebred Beagle Dogs 
     An aliquot of test article (i.e., placebo (control) or Capsaicin Formulation A) was administered as a single dose via intraarticular injection to dogs, and analysis was performed to check for evidence of toxicity. Capsaicin Formulation A was prepared based on procedures described above for Capsaicin Formulation 1, and a description of Capsaicin Formulation A is provided in the following table. 
                                     Capsaicin Formulation A                                            An aqueous, capsaicin injectable formulation containing:           a. 0.05% (w/w) of trans-capsaicin;           b. 1% (w/w) of macrogol 15 hydroxystearate;           c. 0.01% (w/w) dibutylated hydroxytoluene;           d. 50 mM of buffer that is a mixture of sodium acetate and acetic acid;           e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof;           f. 0.6% (w/w) of sodium chloride;           g. q.s. with water (i.e., about 97.6% (w/w)); and           having a pH of 5.5.                    
Procedurally, male and female purebred beagle dogs were received from Covance Research Products, Inc. in Cumberland, Va. Animals were acclimated to the test facility for 20 days (males) and 24 days (females) prior to initiation. At initiation of dosing, animals were 7 to 8 months old, and body weights ranged from 7.4 to 11.8 kg for males and 6.5 to 9.2 kg for females. Animals not used on study were placed in the stock colony. Animals were housed in stainless steel cages with Tenderfoot® flooring. Animals were socially housed by sex, unless individually housed during parts of the pre-dose phase, for study-related procedures, or for individual assessment of food consumption. Water was provided ad libitum. Animals were offered Certified Canine Diet #5007 (PMI NUTRITION INTERNATIONAL CERTIFIED LABDIET®); it was provided for 4 to 5 hours each day, unless otherwise specified. Feed was offered following the completion of dosing for each room on the day of dosing or at approximately the same time as the expected start of dosing (±2 hours) on days without dosing. For acclimation purposes, animals had access to feed for longer than 4 to 5 hours on the day of and the day after arrival. Beginning on Day 16 of the dosing phase for females, one animal (Group 3 female) was given canned food once daily.
 
     The male and female dogs were assigned to groups and doses of test articled (i.e., placebo (control) or Capsaicin Formulation A) were administered as indicated in the following table. 
                                                            Dose of   Dose   Concentration of                                     No. of Animals   Capsaicin   Volume   Capsaicin in the                                     Group   Male   Female   (mg)   (mL)   Dose (mg/mL)                                             1 (control)   4   4   0   2   0       2   4   4   0.1   0.2   0.5       3   4   4   0.3   0.6   0.5       4   4   4   1   2   0.5                    
Animals were administered a single dose of test article (i.e., placebo (control) or Capsaicin Formulation A) on Day 1 via intra-articular injection into the stifle joint. Dosing was followed by an observation period of 4 weeks. The vehicle control article (i.e., placebo) was the same as Capsaicin Formulation A except that it did not contain capsaicin. Prior to injection of test article, animals were fasted for the overnight period prior to dosing. Additionally, animals were pre-treated with an intra-articular injection of lidocaine into the right stifle joint on Day 1 of the dosing phase, prior to dose initiation. Animals were anesthetized for administration of lidocaine, which was administered as follows for each group:
 
                                                     Lidocaine                   Volume   Lidocaine           Group   (mL)   Concentration                          1 (control)   0.5   4%           2   2.0   1%           3   1.5   1%           4   0.5   4%                        
Feed was returned following the completion of dosing.
 
     Assessment of toxicity was based on mortality, clinical observations, body weights, food consumption, electrocardiography (ECG), synovial fluid collection, and clinical and anatomic pathology. Blood samples (approximately 2.0 mL) were collected via the jugular or cephalic vein on Day 1 of the dosing phase (see Protocol Deviations). Samples were collected pre-dose and approximately 15 and 30 minutes and 1, 2, 4, 8, and 24 hours post-dose. Animals were not fasted for sample collections, unless fasted for other study procedures. Blood was collected into tubes containing potassium (K2) EDTA as the anticoagulant. Samples were maintained on chilled cryoracks prior and were centrifuged within 1 hour of collection. Plasma was harvested and divided into two approximately aliquots and placed on dry ice, then stored in a freezer set to maintain at a temperature in the range of −60° C. to −80° C., until shipped. Aliquot 1 was shipped on dry ice to the testing laboratory for analysis and Aliquot 2 was retained as backup at the testing facility. Plasma samples were analyzed for capsaicin. Toxicokinetic analysis was performed, which included analysis of Cmax, dose normalized maximum concentration (DN Cmax), Tmax, area under the curve from time 0 to the time of the last measurable concentration (calculated using the linear trapezoidal rule), area under the curve from time 0 to 24 hours (calculated using the linear trapezoidal rule), and elimination half-life. Cageside observations were conducted for each animal once daily during the pre-dose and dosing phases, except on days when detailed observations were conducted. Abnormal findings were recorded. Detailed observations were conducted for each animal three times for males and four times for females during the pre-dose phase and on Days 1, 8, 15, 22, and 28 of the dosing phase. Detailed observations were also collected for each animal on the day of scheduled sacrifice (all surviving animals). Abnormal findings or an indication of normal was recorded. Unscheduled observations were recorded. On the day of dosing, cage-side observations were conducted for each animal at approximately 1, 4, and 8 hours post-dose. Post-dose observation start times for each animal were based on the dosing completion time for each animal. Abnormal findings or an indication of normal was recorded. Body weights were recorded three times for males and four times for females during the pre-dose phase and on Days 1, 8, 15, 22, 28 (females only), and 29 (males only) of the dosing phase. Quantitative food consumption was recorded weekly (unless fasted for other study procedures) to Week 4 and from Days 22 to 28 of the dosing phase. Electrocardiograms (ECGs) were recorded once during the pre-dose phase and once during Week 4 of the dosing phase. Electrocardiograms were recorded using eight leads. Blood samples for hematology, coagulation, and clinical chemistry were collected from fasted animals via a jugular or cephalic vein. Blood samples were collected twice during the pre-dose phase, on Day 2 of the dosing phase, and on the day of scheduled sacrifice. Urine samples for urinalysis were collected chilled during the overnight period before blood collection from animals fasted overnight. Urine samples were collected once during the pre-dose phase, on Day 2 of the dosing phase, and on the day of scheduled sacrifice. Synovial fluid was collected from the knee of all animals on the day of scheduled sacrifice. 
     On Day 29 of the dosing phase, all animals, having been fasted overnight, were anesthetized with sodium pentobarbital, exsanguinated, and necropsied. Terminal body weights were recorded for sacrificed animals. A macroscopic examination of the external features of the carcass; external body orifices; abdominal, thoracic, and cranial cavities; organs; and tissues was performed. Organ weights were recorded at the scheduled sacrifice. Paired organs were weighed together. Bone marrow smears (two slides) were prepared from the sternum of each animal at scheduled sacrifices. 
     Part II—Results of Toxicity Analysis in Dogs 
     No significant local or systemic adverse effects were observed attributable to administration of up to 1 mg dose of trans-capsaicin using Capsaicin Formulation A once on Day 1 of the dosing phase via intra-articular injection to the stifle joint of dogs. The observed effects of administering Capsaicin Formulation A were limited to (i) a minimally to mildly increased number of reactive mononuclear cells in the synovial fluid of the injected stifle, (ii) minimal to slight hypertrophy/hyperplasia and erosion/ulceration and minimal hemorrhage and degeneration of the synovium, and (iii) minimal pigment in the synovium of one female administered a 1 mg dose of trans-capsaicin using Capsaicin Formulation A. No alteration in body weight or body weight gain was observed attributable to administration of Capsaicin Formulation A. No effect on food consumption was observed attributable to administration of Capsaicin Formulation A. No test article-related change in PR interval, QRS duration, QT interval, corrected QT (QTc) interval, or heart rate was observed on Day 23 (males) or 25 (females) of the dosing phase in animals administered 0.1, 0.3, or 1 mg of trans-capsaicin via Capsaicin Formulation A. No abnormal ECG waveforms or arrhythmias attributed to Capsaicin Formulation A were observed during qualitative assessment of the ECGs. No effects on hematology, clinical chemistry, coagulation, or urinalysis tests were identified attributable to administration of Capsaicin Formulation A. Minimally to mildly increased total white blood cell count, due to increased absolute neutrophil and/or monocyte counts, and minimally increased fibrinogen concentration were noted on Day 2 in most animals of all groups, including controls, and were considered secondary to study procedures. No effect on organ weight parameters attributable to Capsaicin Formulation A was observed. 
     Based on these results, the high-dose level of 1 mg of trans-capsaicin administered via Capsaicin Formulation A is the no observed adverse effect level (NOAEL). At a dose level of 1 mg trans-capsaicin administered in the form of Capsaicin Formulation A, the Day 1 combined (males and females) mean C max  and AUC 0-24  values for trans-capsaicin were 9.21 ng/mL and 21.7 ng·h/mL, respectively. 
     Example 9—Autoclave Steam Sterilization of an Exemplary Capsaicin Formulation 
     An aliquot of Capsaicin Formulation A was placed into a container and subjected to autoclave steam sterilization. Capsaicin Formulation A was prepared based on procedures described above for Capsaicin Formulation 1, and a description of Capsaicin Formulation A is provided in the following table. 
     
       
         
           
               
               
             
               
                   
               
               
                   
                 Capsaicin Formulation A 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
            
               
                   
                 An aqueous, capsaicin injectable formulation containing: 
               
               
                   
                 a. 0.05% (w/w) of trans-capsaicin; 
               
               
                   
                 b. 1% (w/w) of macrogol 15 hydroxystearate; 
               
               
                   
                 c. 0.01% (w/w) dibutylated hydroxytoluene; 
               
               
                   
                 d. 50 mM of buffer that is a mixture of sodium acetate and acetic acid; 
               
               
                   
                 e. 0.025% (w/w) of ethylenediaminetetraacetic acid or a salt thereof; 
               
               
                   
                 f. 0.6% (w/w) of sodium chloride; 
               
               
                   
                 g. q.s. with water (i.e., about 97.6% (w/w)); and 
               
               
                   
                 having a pH of 5.5. 
               
               
                   
               
            
           
         
       
     
     Experimental Procedures and results are provided below. 
     Part I—Experimental Procedure for Sterilization Process Providing a F 0 -Value in the Range of 8.8 to 8.9 
     An aliquot of Capsaicin Formulation A was placed into a sealed container. The sealed container containing Capsaicin Formulation A was then placed into an autoclave and subjected to sterilization conditions to achieve an F 0 -value in the range of 8.8 to 8.9. The sterilization conditions involving heating the sterilization chamber of the autoclave to a temperature in the range of 121.7° C. to 122.0° C. and a pressure of about 3.4 barr, holding at the aforementioned conditions for a duration of about 7 minutes, and then returning the autoclave chamber to ambient temperature and pressure. Thereafter, an aliquot of the sterilized Capsaicin Formulation A was analyzed by HPLC, and the HPLC chromatogram compared to the HPLC chromatogram of an aliquot of Capsaicin Formulation A that had not undergone the sterilization procedure. 
     Part II—Results 
     HPLC analysis of the aliquot of Capsaicin Formulation A subjected to the above sterilization revealed that there was no significant loss of capsaicin due to the sterilization procedure. The Capsaicin Formulation A was found to be stable to the sterilization conditions. 
     Part III—Experimental Procedure for Sterilization Process Providing a F 0 -Value in the Range of 25.7 to 26.1 
     An aliquot of Capsaicin Formulation A was placed into a sealed container. The sealed container containing Capsaicin Formulation A was then placed into an autoclave and subjected to sterilization conditions to achieve an F 0 -value in the range of 25.7 to 26.1. The sterilization conditions involving heating the sterilization chamber of the autoclave to a temperature in the range of 121.0° C. to 123.0° C. and pressure of about 3.4 barr, holding at the aforementioned conditions for a duration of about 22 minutes, and then returning the autoclave chamber to ambient temperature and pressure. Thereafter, an aliquot of the sterilized Capsaicin Formulation A was analyzed by HPLC. 
     Part IV—Results 
     HPLC analysis of the aliquot of Capsaicin Formulation A subjected to the above sterilization revealed that there was no significant loss of capsaicin due to the sterilization procedure. The Capsaicin Formulation A was found to be stable to the sterilization conditions. 
     INCORPORATION BY REFERENCE 
     The entire disclosure of each of the patent documents and scientific articles referred to herein is incorporated by reference for all purposes. 
     EQUIVALENTS 
     The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting the invention described herein. Scope of the invention is thus indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.