CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application No.

63/023,320, filed on May 12, 2020. The entire disclosure of the applications identified in this paragraph is incorporated herein by reference.

FIELD

[0002] The present disclosure relates to compositions for oral administration comprising temozolomide, formic acid, polyethylene glycol (PEG), and glycerol and methods for using the same for treating cancer in a subject.

BACKGROUND

[0003] Temozolomide (8-carbamoyl-3-methyl-[3FI]-imidazo-[5, 1 -d]-1 ,2,3,5- tetrazin -4-one) is an alkylating agent used as an oral chemotherapeutic drug. Temozolomide is indicated for treatment of glioblastoma multiforme (GBM) and refractory anaplastic astrocytoma. Temozolomide is unstable in aqueous solutions, which leads to the generation of impurities and/or temozolomide degradation products following storage. The instability renders ready-to-use liquid dosage forms difficult to store.

[0004] Temozolomide is currently administered as 5-250 mg capsules or reconstituted from 10 mg powder for IV infusion. Although temozolomide is not indicated for pediatric use, it is administered to children in off-label use.

[0005] US 5,260,291 first reported temozolomide, polymorphs thereof, and compositions thereof. The reported compositions further comprise dimethyl sulphoxide and arachis oil.

[0006] US 6,251 ,886 reports methods for treating neoplastic meningitis cancer with a microcrystalline suspension of temozolomide, DLPC, DMPC, mannitol, and sodium acetate.

[0007] US 6,987,108 and US 7,786,118 disclose temozolomide compositions and at least one aqueous diluent. The diluent may be urea, L-histidine, L-threonine, L- asparagine, L-serine, and L-glutamine. Additional excipients include PEG.

[0008] US 8,623,868 reports lyophilized temozolomide powder further comprising L-threonine. [0009] Trissel, et al. ( Int . J. Pharm. Compd. Sep-Oct 2006; 10(5): 396-9) describes oral temozolomide suspensions comprising ORA-Sweet® or ORA Sweet SF®, both of which comprise glycol.

SUMMARY

[0010] This section provides a general summary of disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0011] The present disclosure relates to compositions comprising temozolomide, formic acid, and one or more additional excipients. In an embodiment, the excipient may be polyethylene glycol (PEG), and glycerol. The disclosed compositions are stable and for oral administration. In an embodiment, the temozolomide formulation can be administered to children, dysphasic patients, and/or patients having difficulty swallowing oral solid dosage forms.

[0012] In an embodiment, the composition comprises PEG400, and the PEG400:glycerol ratio is between about 75:25 and about 40:60.

[0013] In an embodiment, the composition further comprises metabisulfite, or salt thereof, a taste-masking or taste-enhancing agent, or a combination thereof. [0014] In an embodiment, there is provided a method for treating cancer in a subject, for example a child, the method comprising oral administration of a composition comprising temozolomide, formic acid, PEG, and glycerol. In a further embodiment, the PEG is PEG200 to PEG 600. In a particular embodiment, the PEG is PEG400.

BRIEF DESCRIPTION OF THE DRAWINGS [0015] The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

[0016] FIG. 1 shows temozolomide solubility as a function of dilution of formic acid in water.

DETAILED DESCRIPTION

[0017] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. [0018] The term “temozolomide” refers to the chemical compound 8-carbamoyl- 3-methyl-[3H]-imidazo-[5,1-d]-1 ,2,3,5-tetrazin-4-one, and is also known by the trade names of Temodal®, Temodar®, and Temcad. Unless otherwise noted, temozolomide includes the compound itself and pharmaceutically acceptable salts thereof.

[0019] The term “non-aqueous” refers to compositions (e.g. solutions, liquids, or suspensions) which are free of or essentially free of water.

[0020] The terms “taste-enhancing agent” and “taste-masking agent” refer to compounds or compositions that enhance the palatability of particular compositions, such as temozolomide compositions.

[0021] The term “subject” refers to an animal that can receive administration of the temozolomide composition. In some embodiment, the subject is human. In particular embodiments, the subject is a child, including newborns, infants, toddlers, adolescents, and teenagers. In another embodiment, the subject suffers from dysphagia and/or has difficulty swallowing.

[0022] The term “excipient” refers to compounds or substances that are not pharmaceutically and/or therapeutically active. Excipients are well known in the art and include, but are not limited to, antioxidants, preservatives, solvents, surfactants, dispersing agents, solubilizers, wetting agents, suspension agents, and combinations thereof.

[0023] As used herein, “metabisulfite” (also known as metabisulphite) is not particularly limited with respect to the cation associated with the bisulfite moiety. In some embodiments, the cation is selected from the group consisting of sodium, potassium, rubidium, magnesium, calcium, and ammonium. In a particular embodiment, the metabisulfite is sodium bisulfite. Compositions

[0024] The present disclosure provides a composition comprising temozolomide or its derivative, such as a metabolite, and one or more excipients. Such compositions include pharmaceutical compositions comprising temozolomide, formic acid, PEG, and glycerol. Temozolomide is the active ingredient of the formulation and its amount can be adjusted. Generally, all known/approved amounts of temozolomide can be used with the formulation. In an embodiment, the temozolomide is present in an amount of about 10 to about 500 mg. In a further embodiment, the temozolomide is present in an amount of about 50 to about 250 mg. In a particular embodiment, the temozolomide is present at a concentration of about 10 mg/ml_.

[0025] In an embodiment, the formic acid is present at in an amount of about 0.05% to about 10% (w/v). In another embodiment, the formic acid is present in an amount of about 2% to about 6% (w/v). In a particular embodiment, the formic acid is present in an amount of about 6% (w/v), about 5% (w/v), about 4% (w/v), about 3% (w/v), or about 2.5% (w/v).

[0026] In an embodiment, the combination of the PEG and glycerol is present in an amount of between about 90% to about 99% (w/v) of the composition. In an embodiment, the PEG is PEG400. Controlling the ratio of PEG:glycerol may be useful to improve stability of the formulations. In one embodiment the PEG:glycerol ratio is between 100:0 and 0:100. In a further embodiment, the PEG and glycerol are present in a ratio of between about 75:25 and about 40:60, by volume. In a particular embodiment, the PEG:glycerol ratio is about 60:40. In another particular embodiment, the PEG:glycerol ratio is about 50:50. In another embodiment, the PEG may be super refined.

[0027] In an embodiment, the temozolomide composition is free of, or essentially free of water. In a particular embodiment, the temozolomide composition comprises up to 2% (v/v) water. In another embodiment, the temozolomide composition does not comprise water.

[0028] The temozolomide composition can further comprise additional excipients and non-limiting examples of such excipients include metabisulfite, antioxidants, preservatives, solvents, surfactants, dispersing agents solubilizers, wetting agents, suspension agents, taste-enhancing or taste-masking agent, and combinations thereof. In a particular embodiment, the metabisulfite is sodium metabisulfite. [0029] In an embodiment, the excipient includes an antioxidant. The antioxidant may be one or more of ascorbic acid, ascorbyl palmitate, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), propyl gallate, alpha-tocopherol, mono-f-butyl hydroquinone (TBHQ), and tartaric acid.

[0030] In an embodiment, the excipient includes a preservative. The preservative may be one or more of beta-phenylethyl alcohol, benzalkonium chloride, benzyl alcohol, benzoic acid and salts thereof, boric acid and salts thereof, cetyltrimethyl ammonium bromide, chlorhexidine gluconate, chlorhexidine acetate, ethanol, parabens, alkyl parabens (e.g., methyl paraben, propyl paraben), sodium benzoate, and sorbic acid and salts thereof.

[0031] In an embodiment, the excipient includes a solvent. The solvent may be one or more of a polyethylene glycol (e.g., PEG300), propylene glycol, N,N dimethylacetamide (DMA), and dimethyl isosorbide.

[0032] In an embodiment, the excipient includes a surfactant, solubilizer, or wetting agent. The surfactant, solubilizer, or wetting agent may be one or more of polyoxyl 15 Hydroxystearate (Kolliphor ^® HS-15), polyoxyl castor oil (Kolliphor ^® RH40), poloxamer 407 (Kolliphor ^® P407), poloxamer 188 (Kolliphor ^® P188), lauryl polyoxyl-32 glycerides (Gelucire ^® 44/14), polyethylene glycol sorbitan monolaurate (Tween 20 ^® or polysorbate 20), sorbitan trioleate (Span ^® 85), and sodium dioctyl sulfosuccinate. [0033] In an embodiment, the excipient includes a suspending agent. The suspending agent may be one or more of synthetic suspending agents (e.g. carbomers, colloidal silica, polyvinyl pyrollidone, polyvinyl alcohol, and the like), semi synthetic suspending agents (e.g., cellulosic polymers, such as hydroxypropylmethylcellulose and the like), natural suspending agents (e.g., polysaccharides, starch, alginates, and the like), and inorganic suspending agents (e.g., clay, bentonite, and the like).

[0034] In another embodiment, the temozolomide composition further comprises metabisulfite. In a specific embodiment, the metabisulfite is sodium metabisulfite. In a particular embodiment, the metabisulfite, including sodium metabisulfite, is present in an amount between about 0.01 % and about 2.0% (w/v). In still further embodiments, the metabisulfite is present in an amount of about 0.05% (w/v) or about 0.1 % (w/v).

[0035] In another embodiment, the temozolomide composition further comprises a taste-enhancing or taste-masking agent. In an embodiment, the taste- enhancing agent or taste-masking agent is selected from the group consisting of citric acid, sorbitol, cherry, raspberry, mint, spearmint, peppermint orange, caramel, acesulfame K, tutti frutti, dextrose, fructose, glucose, mannitol, sucrose, grape, citrus, lemon, blackcurrant, tropical fruit punch, lime, bubblegum, lime, strawberry, butterscotch, berry and a combination thereof. In a particular embodiment, the taste enhancing agent or taste-masking agent is present in an amount of between about 0.01 % and about 0.2% (w/v). In a still further embodiment, the taste-enhancing agent or taste-masking agent is present in an amount of about 0.05% (w/v) or about 0.1 % (w/v). In a particular embodiment, the taste-enhancing agent or taste-masking agent is tutti frutti in an amount of about 0.05% (w/v). In another particular embodiment, the taste-enhancing agent or taste-masking agent is a combination of sorbitol and mint in a ratio of 75:25 in an amount of about 0.1 % (w/v).

[0036] In a particular embodiment, the composition comprises about 50 about 250 mg temozolomide; about 2% to about 6% (w/v) formic acid, and about 90% to about 99% (v/v) PEG400 and glycerol, wherein the ratio of PEG400:glycerol by volume is between about 75:25 and about 40:60. The composition may further comprises a taste-enhancing or taste-masking agent and/or metabisulfite as described above. In specific embodiments, the temozolomide composition may comprise the following ingredients:

[0037] In another embodiment, the temozolomide composition is in the form of a solution, suspension, or liquid. In a further embodiment, the temozolomide composition is a non-aqueous solution. [0038] The composition of the present disclosure is to address, among other things, stability issues of temozolomide in an aqueous solution. The stable temozolomide composition of the present disclosure is suitable for a ready-to-use liquid dosage drug product. In an embodiment, the temozolomide composition is stable under refrigeration (e.g. 4-5°C) for one month, two months, three months, or longer. In another embodiment, the temozolomide is stable for up to six months under refrigeration. In an alternative embodiment, the temozolomide composition is stable at room temperature (e.g. about 21-25°C) for one week, two weeks, three weeks, four weeks, one month or longer.

Methods of treatment

[0039] The present disclosure provides various methods of using the temozolomide composition for the treatment of disease(s) such as cancer. In an embodiment, the temozolomide composition is administered to a subject to treat cancer, wherein the subject is in need of such treatment. Various cancers can be treated by the composition and in some embodiments, the cancer is selected from the group consisting of brain cancer, breast cancer, neuroblastoma, and hematological malignancy. In a specific embodiment, the hematological malignancy is lymphoma or leukemia.

[0040] The temozolomide composition therapy can be combined with various cancer treatments known in the art. In an embodiment, the temozolomide composition is administered to the subject in conjunction with radiotherapy. In still another embodiment, the temozolomide composition is administered before, after, or concurrently with an additional chemotherapeutic agent. Non-limiting examples of such additional therapeutic agent include.

[0041] The temozolomide composition therapy is contemplated for pediatric use. In a particular embodiment, the subject is a child.

[0042] The temozolomide composition therapy is also contemplated for subjects suffering from dysphagia and for non-dysphagic patients.

EXAMPLES

[0043] Example 1 : Solubility of temozolomide in formic acid [0044] Solubility of temozolomide in various solvents was measured. Briefly, an initial solubility screen was performed according to a miniature “shaking flask” procedure. 100 mg temozolomide was placed in an Eppendorf vial and 1 .0 mL of the solvent to be tested was added. The mixture was vortexed for 5 minutes and shaken for 24 hours at room temperature. The vial was then centrifuged for 10 minutes at 20,000 rpm. Temozolomide concentration was determined via high pressure liquid chromatography (HPLC). Table 1 below reports the solubility of temozolomide in various solvents.

[0045] Table 1

The significant solubility in DMSO is consistent with what is known in the art. Since 100% DMSO has limited applicability for pharmaceutical formulation, the Inventors considered an alternative approach to form temozolomide co-crystals to improve solubility. 100 mg temozolomide was granulated with 3 ml_ of each of formic acid, acetic acid, salicylic acid, saccharin, tartaric acid succinic acid, sucralose, fumaric acid, and acetonitrile. Briefly, the temozolomide powder was mortared for 15 minutes or ball milled for 5 minutes at 30 Hz as the solvent was added dropwise. The mixture was transferred to a 20 mL glass vial an allowed to dry.

[0046] Surprisingly, all temozolomide dissolved completely in formic acid, indicating a minimum solubility of temozolomide in formic acid of at least 30 mg/mL. Inventors subsequently determined that temozolomide has a maximum solubility in formic acid of over 200 mg/mL. For comparison, the temozolomide achieved only a 6.5 mg/mL solubility in acetic acid, the closest carboxylic acid to formic acid.

[0047] Temozolomide 10 mg in a mixture of 400 pL glacial acetic acid and 600 pL PEG/glycerol mixture, but no formic acid (final temozolomide concentration of 10 mg/mL), could only be dissolved after multiple cycles of vortexing, sonication, and heating to 65°C. However, 40% acetic acid can be toxic. Temozolomide was insoluble or not fully soluble in compositions comprising 0%, 5%, and 10% glacial acetic acid. Addition of up to 1 % formic acid in glacial acetic acid was not capable of dissolving 10 mg temozolomide. Combining the 10% glacial acetic acid with glycerol and one of PEG400, PEG300, or PEG200 did not dissolve temozolomide at the desired 10 mg/mL concentration, despite vortexing, sonicating, and warming the solutions to 40°C. The solutions turned a pink color prior to refrigeration at 5°C and showed precipitation. [0048] Addition of water to the temozolomide-formic acid composition reduced temozolomide solubility. When the 200 mg/mL temozolomide solution in formic acid was diluted with water to a 5% formic acid solution, temozolomide solubility dropped to about 5 mg/mL. Figure 1 shows temozolomide solubility as a function of dilution of formic acid in water.

[0049] Solubility trials to dissolve 250-400 mg of succinic acid, citric acid, or tartaric acid in 5 mL PEG400, followed by vortexing and heating to 60°C, did not result in clear solutions.

[0050] Additional trials were conducted to compare temozolomide solubility in formic acid with temozolomide solubility in acetic acid, succinic acid, citric acid, and tartaric acid.

[0051] Example 2: Addition of PEG400 and glycerol to a temozolomide-formic acid solution.

[0052] The inventors investigated additional excipients to reduce the amount of formic acid while maintaining temozolomide solubility and stability. Temozolomide was dissolved in formic acid to about 200 mg/mL and diluted with various combinations of water, glycerol, and PEG400 to a final temozolomide concentration of about 10 mg/mL. The formulations were monitored for 1 week in a dark at room temperature. After seven days, the temozolomide concentration in the PEG400/glycerol combination remained stable at about 10 mg/mL. For all aqueous combinations (i.e. PEG400/water, glycerol/water, and PEG400/glycerol/water), temozolomide concentrations dropped by at least 40% after one week. [0053] Based on this test, a second stability study explored the stability of temozolomide in various PEG400:glycerol ratios. Temozolomide was dissolved in formic acid to 200 mg/mL and diluted to about 10 mg/mL with the following combinations of PEG400 and glycerol: 100:0, 90:10, 75:25, 50:50, 25:75, 10:90, and 0: 100. The samples were stored in the dark at room temperature (21 °C) or 5°C for up to 63 days. As shown in Table 2, below, temozolomide remained stable and soluble (e.g. it did not precipitate) after 63 days when formulated with 75:25 and 50:50 PEG400:glycerol combinations. For all other formulations, precipitation was observed after only 49 days. 2-azahypoxanthine (also known as Ph. EUR impurity E) is a major degradation product of temozolomide. The presence of PEG400 appears to negatively influence temozolomide stability in addition to its bitter taste.

[0054] Table 2

[0055] Example 3: Addition of metabisulfite [0056] The inventors then investigated the effect of sodium metabisulfite on

PEG400-containing temozolomide formulations. 200 mg/mL temozolomide dissolved in formic acid was diluted in 50:50 PEG400:glycerol to a final concentration of 10 mg/mL temozolomide in the presence or absence of 0.1 % (w/v) sodium metabisulfite. After 14 days at room temperature, no 2-azahypoxanthine (Ph EUR impurity E) was detected in the sodium metabisulfite-containing formulation and the color of the solution did not change. In contrast, 2-azayhypoxanthine was detected at 0.5% after 14 days, and the solution turned pink.

[0057] Example 4: Formic acid concentrations

[0058] Temozolomide formulations were prepared to investigate the lower limit of formic acid. Temozolomide formulations comprising 50:50 PEG400:glycerol and 5%, 4%, 3%, and 2.5% formic acid were prepared. Precipitation was observed at formic acid concentrations of 3% and lower.

[0059] Example 5: Flavoring selection

[0060] Twenty seven artificial flavors and sweeteners were selected for their potential to enhance the palatability of temozolomide formulations, particularly for pediatric use or administration to dysphagic patients. Formulations comprising 10 mg/mL temozolomide in formic acid with a PEG400:glycerol ratios of 75:25 and 50:50 were prepared with about 0.1 % citric acid, sorbitol, cherry, raspberry, mint, orange, caramel, acesulfame K, or tutti-frutti. Flavored compositions comprising 50:50 PEG400:glycerol were preferred over the 75:25 PEG400:glycerol combination by a taste panel. Additional taste tests identified temozolomide preparations comprising 0.05% tutti-frutti or 0.1 % mixture of a 25:75 mintsorbitol ratio as palatable.

[0061] Additional taste panels found preparations of 6% formic acid comprising 60:40 or 50:50 PEG400:glycerol ratio without an additive to be acceptable.

[0062] Example 6: Long term stability of temozolomide formulations [0063] Temozolomide was dissolved in 6% formic acid and diluted to 10 mg/mL in a 60:40 PEG400:glycerol combination alone or in the presence of 0.1 % sorbitol/mint (75:25 v/v ratio) or 0.05% tutti-frutti flavoring or stored under a nitrogen atmosphere. Sodium metabisulfite was added to some compositions at 0.05% or 0.1 %. The compositions were tested for impurities at months one, two, three, and six. Tables 3 and 5 below show the stability of 10 mg/mL temozolomide compositions in 6% formic acid with a 60:40 ratio of PEG:400:glycerol combination after one month, two months, three months, and six months at 5°C and 25°C, respectively. Tables 4 and 6 show the level of 2-azahypoxanthine and total impurities at the same time points and conditions. [0064] Table 3: Long term stability at 5°C — relative amount of temozolomide

[0065] Table 4: Long term stability at 5°C — presence of impurities.

* There were no detectable 2-azahypoxanthine upon preparation of the composition.

[0066] Table 5: Long term stability at 25°C — relative amount of temozolomide

[0067] Table 6: Long term stability at 25°C — presence of impurities

^* There were no detectable 2-azahypoxanthine upon preparation of the composition. [0068] Additional data is collected at the end of months 9, 12, 24, and 36 to fully disclose temozolomide stability.

[0069] Example 7: Second long term stability of temozolomide formulations [0070] Temozolomide was dissolved in 6% formic acid and diluted to 10 mg/mL in a 60:40 PEG400:glycerol combination and stored under a normal atmosphere or a nitrogen atmosphere. The compositions were tested for impurities at months one, two three, and six. Tables 7 and 9 below show the stability of 10 mg/mL temozolomide compositions in 6% formic acid with a 60:40 ratio of PEG:400:glycerol combination after one month at 5°C and 25°C, respectively. Tables 8 and 10 below show the level of 2-azahypoxanthine and total impurities at the same time points and conditions.

[0071] Table 7: Long term stability at 5°C — relative amount of temozolomide

[0072] Table 8: Long term stability at 5°C — presence of impurities

^* There were no detectable 2-azahypoxanthine upon preparation of the composition. [0073] Table 9: Long term stability at 25°C — relative amount of temozolomide

[0074] Table 10: Long term stability at 25°C — presence of impurities

^† 2-azahypoxanthine was initially present at 0.09% upon formulation of the composition.

[0075] Additional data is collected at the end of months 9, 12, 24, and 36 to fully disclose temozolomide stability.

[0076] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.