Crystalline (+)-Tetrabenazine

Abstract

This application relates to crystalline forms of (+)-tetrabenazine. This application also relates to pharmaceutical compositions comprising crystalline forms of (+)-tetrabenazine, as well as methods of using the crystalline forms of (+)-tetrabenazine in the treatment of hyperkinetic disorders, and methods of obtaining said crystalline forms.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 268,017, filed February 15, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] Technical Field This application relates to crystalline forms of (+)-tetrabenazine. This application also relates to pharmaceutical compositions comprising crystalline forms of (+)-tetrabenazine, as well as methods of using the crystalline forms of (+)-tetrabenazine in the treatment of hyperkinetic movement disorder, and methods of obtaining said crystalline forms. [Background technology]

[0003] background Tetrabenazine (TBZ), also known as Ro 1-9569, is a benzoquinolizine derivative with the chemical name 1,3,4,6,7,11b-hexahydro-9,10-dimethoxy-3-(2-methylpropyl)-2H-benzo[a]quinolizin-2-one (GB 789,789 and US 2,830,993). TBZ exerts its dopamine-depleting effect by reversibly binding to vesicular monoamine transporter 2 (VMAT2) and inhibiting monoamine uptake into granule vesicles of presynaptic neurons, thereby increasing their degradation by monoamine oxidase in the cytoplasm (Scherman, D., Jaudon, P., Henry, J., Characterization of the monoamine carrier of chromaffin granule membrane by binding of [2-3H]dihydrotetrabenazine, Proc. Natl. Acad. Sci. USA, 1983, 80:584-588; Thiriot, DS, Ruoho, EA, Mutagenesis and Derivatization of Human Vesicular Monoamine Transporter 2 (VMAT2) Cysteines Identifies Transporter Domains Involved in Tetrabenazine Binding and Substrate Transport (Mutagenesis and Derivatization of Human Vesicle Monoamine Transporter 2 (VMAT2) Cysteines Identifies Transporter Domains Involved in Tetrabenazine Binding and Substrate Transport), J. Biol. Chem., 2001, 276:27304-27315).TBZ was approved in the UK in 1971 and more recently (August 15, 2008) by the FDA in the US as the first drug to treat chorea associated with Huntington's disease (Mestre, T.. Ferreira, J., Coelho, MM, Rosa, M., Sampaio, C., Therapeutic interventions for symptomatic treatment in Huntington's disease, Cochrane Database Syst. Rev., 2009, 3, CD006456). TBZ is sold under the trade names Nitoman™ and Xenazine™, among others.

[0004] Xenazine has been approved by the FDA to treat chorea associated with Huntington's disease, but the safety and efficacy of this treatment are subject to dose-limiting side effects. In particular, the dose must be determined for each individual patient through a lengthy process of dose titration. Titration to the most effective dose is limited by the onset of side effects [e.g., drowsiness (36.5%), parkinsonism (28.5%), depression (15.0%), insomnia (11.0%), irritability or anxiety (10.3%), and akathisia (9.5%) (J. Jankovic and J. Beach, Long-term effects of tetrabenazine in hyperkinetic movement disorders, Neurology, 1997 Feb, 48(2):358-62). This process raises safety concerns for each patient as side effects are induced and limits the efficacy of the treatment in that the optimal dose may not be reached before the onset of side effects. Evidence indicates that side effects associated with tetrabenazine are related to elevated peak plasma concentrations of the active metabolite.

[0005] TBZ has two chiral centers at carbon atoms 3 and 11b and can theoretically have four isomeric forms. However, due to the thermodynamic instability of the cis-isomer of TBZ, the marketed drugs Nitoman™ or Xenazine™ are only available in the racemic form of (+)-(3R,11bR)-TBZ and (-)-(3S,11bS)-TBZ (trans-isomer of TBZ) as shown in Scheme 1 (Johannes M., Altmann KH, A ring-closing metathesis-based approach to the synthesis of (+)-tetrabenazine, Org. Lett., 2012 Jul 20, 14(14):3752-5, 2012 Jun 28;Yao Z, Wei X, Wu X, et al., Preparation and evaluation of tetrabenazine enantiomers and all eight stereoisomers of dihydrotetrabenazine as VMAT2 inhibitors. all eight stereoisomers of dihydrotetrabenazine as inhibitors), Eur. J. Med. Chem., 2011, 46(5):1841-1848).

[0006] [ka] Scheme 1. Structures of trans-tetrabenazine and its enantiomers, (+)-TBZ and (-)-TBZ.

[0007] TBZ has low and variable bioavailability. In vivo, TBZ undergoes rapid and extensive hepatic metabolism to its corresponding 2-hydroxy derivative (dihydrotetrabenazine (DHTBZs), Scheme 2) as the pharmacologically active species. Importantly, the binding of DHTBZs to VMAT2 is highly stereospecific, with Ki values ​​of 3.96 nM and 13.4 nM for the (+)-α-dihydro and (+)-β-dihydro derivatives derived from (+)-TBZ, (2R,3R,11bR)-DHTBZ and (2S,3R,11bR)-DHTBZ, respectively. In contrast, the binding affinities for the corresponding reduction products derived from (-)-TBZ are only at the micromolar level (23.7 μM and 2.5 μM for (-)-α-DHTBZ and (-)-β-DHTBZ, respectively) [Yao, Z., Wei, X., Wu, X., Katz, JL, Kopajtic, T., Greig, NH, Sun, H., Eur. J. Med. Chem., 2011, 46;1841; Kilbourn, MR, Lee, LC, Heeg, MJ, Jewett, DM, Chirality, 1997, 9;59. Kilbourn, M., Lee, L., Vander Borght, T., Jewett, D., Frey, K., Eur. J. Pharmacol., 1995, 278:249].

[0008] [ka] Scheme 2. Structure of the TBZ metabolite (DHTBZ) with a trans configuration at C-3 versus C-11b.

[0009] Furthermore, the (2R,3R,11bR)-DHTBZ ((+)-α-DHTBZ) and (2S,3R,11bR)-DHTBZ ((+)-β-DHTBZ) isomers show negligible binding to dopamine receptors, suggesting that these isomers are unlikely to encounter dopamine receptors and cause dopaminergic side effects (Clarke I., Turtle R., Johnston G., International Patent Application Publication No. WO2005077946). Furthermore, they lack the undesirable sedative effects associated with TBZ. The stereospecific binding profile of DHTBZ indicates that TBZ enantiomers and DHTBZ stereoisomers may have different pharmacological and / or toxicological profiles that are not yet clear. It is therefore highly desirable to develop practical access to optically pure TBZ enantiomers and DHTBZ stereoisomers to aid in the development of more potent and safer drugs for the treatment of hyperkinetic disorders such as chorea associated with Huntington's disease.

[0010] TBZ racemate or deuterated TBZ racemate can be either crystalline or amorphous. Crystalline forms of racemic TBZ have been reported in WO2012081031A1 and WO2015175505A1, and crystalline forms of deutetrabenazine racemate have been reported in WO2014047167A1 and US9550780B2. Jayachandra and coworkers have disclosed methods for the preparation of amorphous deutetrabenazine, such as a process for making amorphous deutetrabenazine by techniques such as spray drying or distillation (WO2019130252A2). Amorphous tetrabenazine is also commercially available from Biorbyt Ltd (Cambridge, Cambridgeshire, CB4 0WY, United Kingdom). Different crystalline forms of a drug compound may have different properties, such as crystal packing, thermodynamic, spectroscopic, kinetic, surface and mechanical properties. A particular crystalline form of a drug compound may be less sensitive to heat, relative humidity (RH) and / or light, resulting in desirable stability and shelf life. A particular crystalline form of a drug compound may also confer more favorable flowability, compressibility and / or density properties, thereby resulting in more desirable properties for formulation and / or pharmaceutical manufacturing. A particular crystalline form of a drug compound may also have an optimal solubility that allows for the achievement of a desirable dissolution profile and / or a unique pharmacokinetic profile.

[0011] It is well established that it is impossible to predict whether any given compound will exhibit crystalline polymorphism or amorphous form. Therefore, it is impossible to know the number and type of crystalline forms that may exist for (+)-TBZ, or the suitable method for preparing any given crystalline form. Moreover, it remains elusive to predict the properties of any unknown crystalline form and how they differ from other crystalline forms of the same compound (Joel Bernstein, Polymorphism in Molecular Crystals, Oxford University Press, New York, 2002). Therefore, there remains a need for new crystalline forms of (+)-TBZ for use in the preparation of pharmaceuticals with improved properties. Summary of the Invention

[0012] summary The objective of the present application is not only to provide crystalline forms of (+)-TBZ, but also to provide new approaches to improve the properties of (+)-TBZ for the treatment of hyperkinetic disorders. The present application provides crystalline forms of (+)-TBZ, processes for preparing the crystalline forms of (+)-TBZ, pharmaceutical compositions containing the crystalline forms of (+)-TBZ and uses of the crystalline forms of (+)-TBZ for the treatment of hyperkinetic disorders. In some embodiments, the application provides a crystalline form of (+)-tetrabenazine, wherein the crystalline form has an X-ray diffraction spectrum comprising peaks at diffraction 2θ angles of 8.6±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 22.6±0.2°, and 23.1±0.2°.

[0013] In some embodiments, the crystalline form of (+)-tetrabenazine is Form 1. In certain embodiments, the X-ray diffraction spectrum of Form 1 includes peaks at 2θ angles of 6.5±0.2°, 8.6±0.2°, 12.1±0.2°, 14.1±0.2°, 15.0±0.2°, 16.5±0.2°, 17.3±0.2°, 17.9±0.2°, 22.6±0.2°, and 23.1±0.2°. In certain embodiments, the X-ray diffraction spectrum of Form 1 comprises the peaks shown in Table 2 of the present application. In certain embodiments, Form 1 has an X-ray powder diffraction spectrum represented by diffraction angles 2θ angles substantially as shown in FIG. 1A or FIG. 1B. In some embodiments, the crystalline form of (+)-tetrabenazine is Form 2. In certain embodiments, the X-ray diffraction spectrum of Form 2 contains peaks at 2θ angles of 8.6±0.2°, 12.1±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 17.9±0.2°, 22.6±0.2°, and 23.1±0.2°. In certain embodiments, the X-ray diffraction spectrum of Form 1 comprises the peaks shown in Table 3 of the present application. In certain embodiments, Form 2 has an X-ray powder diffraction spectrum represented by diffraction angles 2θ angles substantially as shown in FIG. 2A or FIG. 2B. In certain embodiments, Form 2 has a differential scanning calorimetry scan spectrum comprising an endothermic peak at 115±5° C. In certain embodiments, Form 2 has a differential scanning calorimetry scan spectrum substantially as shown in Figure 12A or Figure 12B or Figure 12C. In certain embodiments, Form 2 has a thermogravimetric profile substantially as shown in FIG. 13A or FIG. 13B or FIG. 13C. The present disclosure provides methods for preparing crystalline forms of (+)-tetrabenazine, including Form 1 and Form 2.

[0014] In some embodiments, the crystalline form is Form 1 and the method comprises: a) obtaining a salt of (+)-TBZ from racemic TBZ using a resolving agent, preferably the resolving agent is (1S)-(+)-10-camphorsulfonic acid ((+)-CSA); b) dissolving a salt of (+)-TBZ in a solvent to obtain a solution; c) adjusting the pH of the solution to a basic condition, preferably to pH 7.5 to 8.5, with a pH adjuster; d) obtaining Form 1 by filtration; Includes. In a particular embodiment, the solvent in step (b) is any liquid substance capable of dissolving (+)-TBZ. Preferably, the solvent is selected from the group consisting of methanol, ethanol, and N-methyl-2-pyrrolidone. In certain embodiments, the pH adjusting agent in step (c) is any agent capable of adjusting the solution to basic conditions. Preferably, the pH adjusting agent is ammonium hydroxide, sodium hydroxide, or sodium carbonate, more preferably ammonium hydroxide.

[0015] In some embodiments, the crystalline form is Form 2 and the method comprises: a) obtaining a salt of (+)-TBZ from racemic TBZ using a resolving agent, preferably the resolving agent is (1S)-(+)-10-camphorsulfonic acid ((+)-CSA); b) dissolving a salt of (+)-TBZ in a solvent to obtain a solution; c) optionally adjusting the pH of the solution to basic conditions, preferably pH 7.5 to 8.5, with a pH adjuster; d) adding an antisolvent to the solution of step (b); e) obtaining Form 2 by filtration; Includes. In a particular embodiment, the solvent in step (b) is any liquid substance capable of dissolving (+)-TBZ. Preferably, the solvent is selected from the group consisting of methanol, ethanol, and N-methyl-2-pyrrolidone. In certain embodiments, the pH adjusting agent in step (c) is any agent capable of adjusting the solution to basic conditions. Preferably, the pH adjusting agent is ammonium hydroxide, sodium hydroxide, or sodium carbonate, more preferably ammonium hydroxide. In a particular embodiment, the antisolvent in step (d) is any liquid substance in which (+)-TBZ is poorly soluble. Preferably, the antisolvent is selected from the group consisting of water and polyvinylpyrrolidone.

[0016] The present application further provides a pharmaceutical composition comprising a crystalline form of (+)-TBZ of the present application and at least one pharma- ceutically acceptable excipient. In some embodiments, the crystalline forms or pharmaceutical formulations of (+)-TBZ of the present disclosure may be formulated into tablets, capsules, pills, granules, liquids, suspensions, syrups, injections (e.g., injection solutions, sterile powders for injection, and concentrated solutions for injection), suppositories, inhalants, or sprays. Furthermore, the crystalline form or pharmaceutical composition of (+)-TBZ of the present disclosure may be administered to a patient or subject in need of the treatment by any suitable mode of administration, such as oral, parenteral, rectal, pulmonary or topical administration. For oral administration, the pharmaceutical composition may be formulated into an oral preparation, such as an oral solid preparation, such as a tablet, capsule, pill, granule, etc.; or an oral liquid preparation, such as an oral liquid, oral suspension, syrup, etc. When formulated into an oral preparation, the pharmaceutical preparation may further include suitable fillers, binders, disintegrants, lubricants, etc. For parenteral administration, the pharmaceutical preparation may be formulated into an injection preparation, such as an injection solution, a sterile powder for injection, and a concentrated solution for injection. When formulated into an injection preparation, the pharmaceutical composition may be manufactured by a method conventional in the pharmaceutical industry. When an injection is formulated, no additional drug may be added to the pharmaceutical preparation, or a suitable additional drug may be added depending on the nature of the drug. For rectal administration, the pharmaceutical preparation may be formulated into a suppository, etc. For pulmonary administration, pharmaceutical preparations may be formulated into an inhalant or nebulizer, etc. In certain preferred embodiments, the crystalline forms of the present disclosure are present in a pharmaceutical composition or medicament in a therapeutically and / or prophylactically effective amount. In certain preferred embodiments, the crystalline forms of the present disclosure are present in a pharmaceutical composition or medicament in a unit dose.

[0017] The present application also provides a method for treating a hyperkinetic disorder, the method comprising administering to a person suffering from a hyperkinetic disorder (e.g., Huntington's disease and tardive dyskinesia, TD) a therapeutically effective amount of a crystalline form of (+)-TBZ or a pharmaceutical composition of the present application. Other features and advantages of the present invention will be apparent from the additional description provided herein, including various examples. The examples provided demonstrate various components and methodologies useful in practicing the invention. The examples do not limit the claimed invention. Based on this disclosure, one of ordinary skill in the art will be able to identify and utilize other components and methodologies useful in practicing the invention. The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. It is not to be understood that the invention is limited to the precise embodiments shown in the drawings. [Brief description of the drawings]

[0018] [Figure 1A] FIG. 1 is an original diagram showing XRD analysis of crystalline (+)-TBZ (free base) Form 1 prepared by chiral resolution. [Figure 1B] FIG. 1B is an enlarged view of FIG. 1A. [Figure 2A] FIG. 13 Original XRD analysis of crystalline (+)-TBZ (free base) Form 2 prepared by chiral resolution followed by addition of an antisolvent. [Figure 2B] FIG. 2B is an enlarged view of FIG. 2A. [Figure 3A] The morphology of crystalline (+)-TBZ is shown using deionized (DI) water as the anti-solvent (Crystallization of (+)-TBZ: 1.5 g / 50 mL of ethanol, anti-solvent: 50 mL of deionized (DI) water, 1 mL / min). [Figure 3B] The morphology of crystalline (+)-TBZ is shown using deionized (DI) water as the anti-solvent (Crystallization of (+)-TBZ: 1.5 g / 50 mL of ethanol, anti-solvent: 100 mL of deionized (DI) water, 1 mL / min). [Figure 4] The morphology of crystalline (+)-TBZ using 1% aqueous PVP solution as an antisolvent is shown. [Figure 5A] Shown are the morphologies of crystalline (+)-TBZ prepared at different temperatures (Crystallization of (+)-TBZ at 30 °C: Seeding: 1 g (+)-TBZ / 50 mL ethanol; Crystal growth: 10 g (+)-TBZ / 50 mL NMP, 1 mL / min & Antisolvent: 50 mL deionized (DI) water, 1 mL / min). [Figure 5B] Shown are the morphologies of crystalline (+)-TBZ prepared at different temperatures (Crystallization of (+)-TBZ at 5 °C: Seeding: 300 mg (+)-TBZ / 50 mL ethanol; Crystal growth: 10 g (+)-TBZ / 50 mL NMP, 1 mL / min & Antisolvent: 55 mL deionized (DI) water, 1 mL / min). [Figure 5C]Shown are the morphologies of crystalline (+)-TBZ prepared at different temperatures (Crystallization of (+)-TBZ at -5 °C: Seeding: 400 mg (+)-TBZ / 50 mL ethanol; Crystal growth: 10 g (+)-TBZ / 50 mL NMP, 1 mL / min & Antisolvent: 55 mL deionized (DI) water, 1 mL / min). [Figure 6] 1 shows particle size distribution (PSD) of crystalline (+)-TBZ under different temperature control. [Figure 7A] FIG. 1 shows the morphology and particle size distribution (PSD) of crystalline (+)-TBZ produced in a scale-up process (10 gram batch of crystalline (+)-TBZ (D10 / D50 / D90: 50.7 / 87.9 / 140.0 μm)). [Figure 7B] FIG. 1 shows the morphology and particle size distribution (PSD) of crystalline (+)-TBZ produced in a scale-up process (20 gram batch of crystalline (+)-TBZ (D10 / D50 / D90: 50.3 / 83.1 / 130.0 μm)). [Figure 7C] 1 shows the PSD of crystalline (+)-TBZ produced under a scale-up process. [Figure 8] The configuration of the cooling chamber is shown. [Figure 9] FIG. 1 shows a microscopic image of crystalline (+)-TBZ obtained by the cooling process with stirring at 200 rpm on a 3 gram scale. [Figure 10] FIG. 1 shows a microscopic image of crystalline (+)-TBZ obtained by the cooling process with stirring at 200 rpm on a 12 gram scale. [Figure 11] FIG. 1 shows a microscopic image of crystalline (+)-TBZ obtained by the cooling process with stirring at 500 rpm on a 12 gram scale. [Figure 12A] FIG. 1 shows a differential scanning calorimetry (DSC) analysis of crystalline (+)-TBZ (Crystalline (+)-TBZ, D50 approx. 35 μm). [Figure 12B] FIG. 1 shows a differential scanning calorimetry (DSC) analysis of crystalline (+)-TBZ (Crystalline (+)-TBZ, D50 approx. 50 μm). [Figure 12C]1 shows a differential scanning calorimetry (DSC) analysis of crystalline (+)-TBZ (Crystalline (+)-TBZ, rods). [Figure 13A] 1 shows the thermogravimetric analysis (TGA) of crystalline (+)-TBZ (Crystalline (+)-TBZ, D50 approx. 35 μm). [Figure 13B] 1 shows the thermogravimetric analysis (TGA) of crystalline (+)-TBZ (crystalline (+)-TBZ, D50 approx. 50 μm). [Figure 13C] 1 shows the thermogravimetric analysis (TGA) of crystalline (+)-TBZ (crystalline (+)-TBZ, rod-shaped). [Figure 14] FIG. 1 shows the sustained release of (+)-TBZ from various polymer formulations containing crystalline (+)-TBZ. [Figure 15] 1 shows the sustained release of (+)-TBZ from various SAIB-based formulations containing crystalline (+)-TBZ. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Detailed Description Various publications, articles and patents are cited in the background and throughout the specification; each of these references is hereby incorporated by reference in its entirety. The discussion of documents, acts, materials, devices, articles and the like which has been included in the specification is for the purpose of providing a suitable context for the present invention. Such discussion is not an admission that any or all of these items form part of the prior art with respect to any invention disclosed or claimed. Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Unless otherwise specified, certain terms used in this application have the meaning as set forth herein. All patents, published patent applications, and publications cited herein are incorporated herein by reference as if set forth herein in their entirety.

[0020] Thus, the present application provides a method for preparing crystalline forms of (+)-TBZ. The crystalline (+)-TBZ may be in the form of a free base, a salt, a hydrate, or an anhydrate that has one or more desirable properties, such as chemical purity, solubility, dissolution rate, crystalline morphology, polymorphic stability, thermal stability, mechanical stability, storage stability, low content of residual solvents, low hygroscopicity, etc., as well as advantageous processing and handling properties, such as flowability, hydration, compressibility, and bulk density. Preferably, the crystalline (+)-TBZ is in the form of a free base in which the nitrogen atoms are not protonated. Various aspects of the present invention will be described in further detail below by means of embodiments, but are not limited thereto. Each aspect of the present invention may be described by one embodiment or by combining two or more embodiments.

[0021] definition It should be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. As used herein, the term "about" preceding a number or series of numbers means ±10% of the number unless otherwise indicated. For example, "about 100 mg" means 90 to 110 mg. Unless otherwise indicated, the term "at least" preceding a series of elements should be understood to refer to every element in the series. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein which equivalents are intended to be encompassed by the present invention. Throughout this specification and the claims that follow, unless the context requires otherwise, the word "comprise" and variations such as "comprises" and "comprising" are understood to mean the inclusion of a stated integer or step or group of integers or steps, but not the exclusion of any other integer or step or group of integers or steps. As used herein, the term "comprising" can be replaced with the terms "containing" or "including," or, when used herein, with "having."

[0022] As used herein, "consisting of" excludes any element, step, or ingredient not recited in the claim element. As used herein, "consisting essentially of" does not exclude materials or steps that do not materially affect the basic and novel characteristics of the claim. Any of the above terms "comprise," "contain," "include," and "have," whenever used herein in the context of an aspect or embodiment of the invention, can be interchanged with the terms "comprise" or "consist essentially of" to modify the scope of the disclosure. As used herein, the term "and / or" between multiple listed elements is understood to include both individual and combined options. For example, when two elements are joined by "and / or", the first option means that the first element applies without the second element. The second option means that the second element applies without the first element. The third option means that the first and second elements apply together. Any of these options are understood to fall within the meaning and thus meet the requirements of the term "and / or" as used herein. The simultaneous application of multiple options is also understood to fall within the meaning and thus meet the requirements of the term "and / or".

[0023] As used herein, the term "(+)-tetrabenazine or (+)-TBZ free base" refers to the solid form of "(+)-tetrabenazine or (+)-TBZ free base" whose molecule has a chemical structure that is not associated with any acid molecules. As used herein, the term "(-)-tetrabenazine or (-)-TBZ free base" refers to the solid form of "(-)-tetrabenazine or (-)-TBZ free base" whose molecule has a chemical structure that is not associated with any acid molecules. As used herein, the term "racemic mixture, racemic TBZ, racemate, TBZ racemate or racemic TBZ" refers to a mixture of (+)-TBZ and (-)-TBZ in about a 1:1 ratio. As used herein, the term "crystalline (+)-TBZ" is used interchangeably with the terms "(+)-TBZ crystals" and "crystallized (+)-TBZ" and "crystalline form of (+)-TBZ" throughout this specification and the claims that follow, unless the context requires otherwise. As used herein, the term "hydrate" refers to a crystalline solid in which water is incorporated or accommodated in the crystal structure (e.g., water is part of the crystal structure or is encapsulated in the crystal (water inclusion)). Thus, water may be present in stoichiometric or non-stoichiometric amounts. The terms "physical form" and "solid form" are used interchangeably herein and refer to any crystalline and / or amorphous phase of a compound.

[0024] As used herein, X-ray diffraction (also known as powder X-ray diffraction (PXRD), X-ray powder diffraction (XRPD), or X-ray diffraction (XRD)) is an experimental technique that reveals structural information such as chemical composition, crystal structure, crystal size, distortion, preferred orientation, and layer thickness. XRD can be used to analyze a wide range of materials from powders to solids, such as films and nanomaterials. Peaks in an X-ray diffractogram arise at specific diffraction angles (Bragg angles) due to constructive interference from X-rays scattered in parallel planes of atoms in a solid material, and are distributed in an ordered, repeating pattern with long-range positional order. Such solid materials are classified as crystalline materials. Compounds in solid forms that are not crystalline are defined as amorphous materials. Amorphous compounds do not have long-range order and do not show a distinct X-ray pattern (see "Fundamentals of Powder Diffraction and Structural Characterization of Materials" by Vitalij et al., Kluwer Academic Publishers, 2003, page 3). A good X-ray diffractogram should be obtained, with clear, sharp peaks with little background noise, to enable analysis and interpretation of the data. The term "2θ" or "2θ angle" or "2-theta" as used in this application refers to the diffraction angle, where θ is the Bragg angle, and its units are ° or degrees. The error range of 2θ is between ±0.1 and ±0.5, preferably between ±0.1 and ±0.3, and is -0.30, -0.29, -0.28, -0.27, -0.26, -0.25, -0.24, -0.23, -0.22, -0.21, -0.20, -0.19, -0.18, -0.17, -0.16, -0.15, -0.14, -0.13, -0.12, -0.11, -0.10, -0.09, -0.08, -0.07, -0.06, -0.05, It may be -0.04, -0.03, -0.02, -0.01, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, or more preferably ±0.2.

[0025] As used herein, the term "substantially as shown" in reference to XRD means that variability in peak positions and relative intensities of peaks should be taken into account. For example, typical accuracy of 2-theta values ​​is within ±0.2° 2-theta, preferably ±0.1° 2-theta. Furthermore, one skilled in the art will appreciate that relative peak intensities exhibit instrumental variability as well as variability due to crystallinity, preferred orientation, sample preparation, and other factors well known in the art. As used herein, the term "consisting essentially of" with respect to the amount of crystalline (+)-TBZ in a composition means that slight variability in the amount should be taken into consideration. This term should also be understood herein in that the composition comprises at least 96% by weight, preferably 98% by weight, more preferably 99% by weight, and most preferably 99.9% by weight of said crystalline (+)-TBZ, based on the total weight of the composition.

[0026] The crystalline solid forms of (+)-TBZ are sometimes referred to herein as being characterized by graphical data "shown" in the figures. Such data includes, for example, XRD, differential scanning calorimetry, and thermogravimetry. Those skilled in the art will appreciate that factors such as differences in instrument type and response, as well as differences in sample directionality, sample concentration, sample purity, sample history, and sample preparation, may result in differences in the data when presented in graphical form, such as differences in exact peak positions and intensities. However, it is well within the knowledge of those skilled in the art to compare the graphical data in the figures of the present application with graphical data generated for an unknown physical form to confirm that the two sets of graphical data are for the same crystalline form. Multiple polymorphs of a sample can also be determined by XRD. (See U.S. Patent Application No. 20190315744). All powder X-ray diffraction patterns were obtained using methods known in the art using a Bruker D2 Phaser XPRD analyzer A26-X1-A2B0B2A0 (serial number: 209872, Germany) equipped with a Cu anode.

[0027] Thermal analysis measurements are performed with the aim of assessing possible physical and chemical changes in heated samples. Thermal reactions can be endothermic in nature (e.g., melting, boiling, sublimation, evaporation, desolvation, solid-solid phase transition, chemical decomposition, etc.) or exothermic (e.g., crystallization, oxidative decomposition, etc.). The methodology has become popular in the pharmaceutical industry for characterizing polymorphism. Thermal measurements have proven useful for characterizing polymorphic systems. The most commonly applied techniques are thermogravimetric analysis (TGA), differential thermal analysis (DTA), and differential scanning calorimetry (DSC). DSC is a thermodynamic tool for directly assessing the thermal energy uptake that occurs in a sample during a controlled ramp temperature process. Calorimetry is performed throughout the process to monitor the changes in the phase transitions of the sample. The DSC curves presented herein were obtained using a Waters Q200 by methods known in the art. Sample masses ranged from about 1 to about 5 mg. Samples were scanned from 25° C. to 200° C. at 5° C. / min increments.

[0028] TGA is the measurement of the thermally induced mass loss of a material as a function of applied temperature. TGA is limited to transitions that are accompanied by either an increase or a decrease in mass, and is most commonly used to study desolvation processes and the decomposition of compounds. The TGA curves presented herein were obtained using methods well known in the art on a Waters TGA 550. Sample masses ranged from about 5 to about 10 mg. Samples were scanned from 25° C. to 650° C. at 10° C. / min increments. Samples were purged with nitrogen gas at a flow rate of 25 mL / min. Samples were held in standard platinum pans with lids. As used herein, the term "substantially shown" with respect to DSC or TGA means that variability in peak position, peak shape, heat absorbed or released, percent mass loss, and / or curve shape should be taken into account.

[0029] As used herein, a solvent is any liquid substance capable of dissolving (+)-TBZ. As used herein, the term "antisolvent" refers to a liquid in which a compound is poorly soluble. Adding an antisolvent to a solvent reduces the solubility of the compound. As used herein, a mixture of solvents refers to a composition that includes multiple solvents. The starting material used in the process for preparing the crystalline forms of the present disclosure can be (+)-TBZ or racemic TBZ in any form, including but not limited to amorphous form, any crystalline form, and the like. According to an embodiment of the present application, (+)-TBZ can be prepared by chemical resolution of racemic TBZ using a resolving agent, including, but not limited to, (1S)-(+)-10-camphorsulfonic acid ((+)-CSA) as a resolving agent.

[0030] In some embodiments, crystalline (+)-TBZ is prepared by antisolvent precipitation, solvent evaporation or temperature change. Various crystallization methods can be selected depending on the desired physicochemical properties of (+)-TBZ or the subsequent preparation process of the pharmaceutical composition. The present application enables a practical and reproducible method for the preparation of crystalline (+)-TBZ. The method can be easily scaled up under various temperature controls, including room temperature. The process is rapid, requires only a small amount of solvent, and the yield can be more than 80%. More preferably, the yield can be more than 90%. Moreover, the present application shows good crystal size control over different batch sizes. Since the particle size of active pharmaceutical ingredient (API) plays a crucial role in drug release, the API crystallization process invented in this application with simple adjustable API particle size control will bring great advantages to formulation development to control the release profile by API particle size selection. Such adjustable size control can be achieved by, but not limited to, temperature control, API stock solution / antisolvent feed rate and solvent / antisolvent ratio.

[0031] In one embodiment, (+)-TBZ provides greater or comparable amounts of therapeutically active VMAT2 inhibitors [(+)-TBZ and (+)-DHTBZ] in rat liver microsomes than TBZ racemate, while avoiding the generation of any undesired metabolites [e.g., isoforms of (-)-DHTBZs] that may lead to significant side effects due to off-target binding to serotonin (5-HT1A, 5-HT2A, 5-HT2B) or dopamine (D1 or D2) receptors [Harriott et al. "VMAT2 Inhibitors and the Path to Ingrezza(Valbenazine)", Progress in Medicinal Chemistry, Volume 57, pages 87-111 (2018)]. In some embodiments, the methods of the present application are used to tailor the shape and size of crystalline (+)-TBZ. The corresponding physicochemical properties of crystalline (+)-TBZ with defined morphology (shape and size) can affect the quality of the final pharmaceutical composition (e.g., API flowability improvement). In some embodiments, the present application discloses a method to produce crystalline (+)-TBZ in a reproducible manner with controllable batch size, crystal shape and particle size distribution, all with a yield of more than 80%. In yet another embodiment, the crystalline (+)-TBZ obtained according to the methods provided herein exhibits very good flowability, which is of practical benefit to pharmaceutical development (e.g., ease of filling and handling).

[0032] In one embodiment, the pharmaceutical composition comprises crystalline (+)-TBZ, a biocompatible solvent, and a biodegradable polymer selected from the group consisting of homopolymer polylactide or polylactic acid (PLA), copolymer poly(lactic acid-co-glycolic acid) or poly(lactide-co-glycolide) (PLGA), and combinations thereof. The biodegradable polymer has a weight average molecular weight (Mw) ranging from about 1,000 to about 120,000, preferably from about 5,000 to about 40,000, as determined by gel permeation chromatography (GPC). The biodegradable polymer can have one ester end functional group and one hydroxyl end group, and may be made to have one or two carboxyl end groups. The biodegradable polymer can be dissolved in a biocompatible solvent selected from the group consisting of N-methyl-2-pyrrolidone, 2-pyrrolidone, N,N-dimethylformamide, dimethylsulfoxide, benzyl alcohol, benzyl benzoate, triacetin, and combinations thereof to form a polymer solution as a delivery vehicle for the therapeutically active VMAT2 inhibitor.

[0033] In one embodiment, the pharmaceutical composition comprises crystalline (+)-TBZ, a biocompatible solvent, and a biodegradable hydrophobic non-polymeric material. The biodegradable hydrophobic non-polymeric material is sucrose acetate isobutyrate (SAIB). SAIB is an esterification product of the disaccharide sucrose with two acetic acids and six isobutyric acids. SAIB is extremely viscous, with a viscosity greater than 100,000 cPs, and is essentially insoluble in aqueous media. SAIB can be mixed with a biocompatible solvent selected from the group consisting of ethanol, N-methyl-2-pyrrolidone, 2-pyrrolidone, N,N-dimethylformamide, dimethylsulfoxide, benzyl alcohol, benzyl benzoate, triacetin, and combinations thereof, after heating until its viscosity is significantly reduced, to form a low-viscosity solution as a delivery vehicle for therapeutically active VMAT2 inhibitors. In a further embodiment, the crystallinity of (+)-TBZ allows to distinguish the formation of enantiomers from the racemate which is not even convincing by NMR. In a further embodiment, the crystallinity of (+)-TBZ described in this invention is unique and clearly distinguishable from the crystallinity of TBZ racemate by the skilled artisan (WO2012 / 081031A1). EXAMPLES

[0034] Working Example The following examples of the present application are provided to further illustrate the nature of the present application. It should be understood that the following examples are not intended to limit the present application, and the scope of the present application is determined by the appended claims.

[0035] Abbreviation Unless otherwise indicated, abbreviations for chemical reagents and synthetic conditions have their ordinary meanings as known in the art as follows: "EA" means ethyl acetate; "PE" means petroleum ether; "rt" and "rt" and "RT" mean room temperature; "THF" means tetrahydrofuran; "DCM" means dichloromethane; "Hex" means hexane; "DMF" means dimethylformamide; "NMP" means N-methyl-2-pyrrolidone; "PVP" means polyvinylpyrrolidone; "h" stands for hour; "min" means minutes; "MeOH" means methanol. "EtOH" means ethanol. "i-PrOH" means isopropanol.

[0036] Example 1: Preparation of (+)-TBZ (+)-Tetrabenazine was prepared according to the procedure disclosed in CN110092785A. (±)-Tetrabenazine (3 g, 9.45 mmol, 1 equiv.) and (1S)-(+)-1-camphorsulfonic acid (4.39 g, 18.9 mmol, 2.0 equiv.) were added to 30 mL of ethyl acetate (10 V, v / w) and the mixture was refluxed for 96 h. The solution was cooled to room temperature and stirred at RT before lowering the temperature to 10° C. with stirring for 0.5 h. Surprisingly, the white solid disclosed in CN110092785A did not precipitate. The mixture was further cooled to 0° C. After stirring at 0° C. for 8 h, still no solid precipitated, so the mixture was allowed to warm to room temperature (RT) and stirred for an additional 2 days until the solid precipitated. The precipitated product (+)-tetrabenazine-(+)-CSA salt was filtered and washed with 6 mL of ethyl acetate (2V, v / w). The yield of (+)-tetrabenazine-(+)-CSA salt was 24.9% with a chiral purity of 36.32%, compared to the yield of 79.1% and chiral purity of 99.5% disclosed in CN110092785A. This was completely unexpected since the yield and chiral purity of (+)-tetrabenazine were much lower than those disclosed in CN110092785A. This procedure was repeated to confirm the findings.

[0037] Example 2. Preparation of crystalline (+)-TBZ: Chiral Resolution I 20 g of racemic mixtures of (3R,11bR)- and (3S,11bS)-tetrabenazine or TBZ and at least 0.1 molar equivalents of (1S)-(+)-10-CSA were dissolved in hot acetone and stirred for 1 h. Ethyl acetate was added and stirred at RT for 48 h to obtain (+)-TBZ-(+)-CSA salt. The resulting (+)-TBZ-(+)-CSA salt was dissolved in methanol. Aqueous ammonium hydroxide was then added to adjust the pH to 7.5-8.5 before crystallizing (+)-TBZ (free base). The resulting crystalline (+)-TBZ (free base) was then filtered and washed with water to obtain about 4.5 g of a colorless solid. The resulting (3R,11bR)-tetrabenazine or crystalline (+)-TBZ was then dried at 40° C. The final purity was greater than 99% and the yield was 30%. XRD was obtained using a Bruker D2 Phaser XPRD analyzer A26-X1-A2B0B2A0 (serial number: 209872, Germany) equipped with a Cu anode. The divergence and anti-scatter slits were set as 0.2 mm and 1.0 mm, respectively. Approximately 10 mg of sample was scanned from 3° to 45° with a step size of 0.02° per second. The parameters are summarized in Table 1.

[0038] Table 1. X-ray powder diffraction parameters [Table 1]

[0039] FIG. 1A (original) and FIG. 1B (enlarged) show the XRD pattern of crystalline (+)-TBZ (crystalline (+)-TBZ (free base), Form 1) obtained using the chiral resolution method. The characteristic peaks of crystalline (+)-TBZ Form 1 are summarized in Table 2.

[0040] Table 2. List of characteristic peaks: crystalline (+)-TBZ, Form 1 [Table 2]

[0041] Example 3. Preparation of crystalline (+)-TBZ: Chiral Resolution II 5 g of (3R,11bR)- and (3S,11bS)-tetrabenazine or TBZ racemate and at least 0.1 molar equivalents of (1S)-(+)-10-CSA were dissolved in a co-solvent of acetone and ethyl acetate, followed by stirring at RT for 48 hours to obtain (+)-TBZ-(+)-CSA salt. The resulting (+)-TBZ-(+)-CSA salt was dissolved in methanol. The pH was then adjusted to 7.5-8.5 by adding a pH adjuster, ammonium hydroxide. Other pH adjusters can also be used here, examples of which include, but are not limited to, ammonium hydroxide, sodium hydroxide, and sodium carbonate. Water was introduced to crystallize (+)-TBZ to obtain crystalline (+)-TBZ (free base). The final purity was greater than 99%. XRD analysis results were obtained using a Bruker D2 Phaser XPRD analyzer A26-X1-A2B0B2A0 (serial number: 209872, Germany) equipped with a Cu anode. The divergence and anti-scatter slits were set as 0.2 mm and 1.0 mm, respectively. Approximately 10 mg of sample was scanned from 3° to 45° with a step size of 0.02° per second. The parameters were identical to those summarized in Table 1. Figure 2A (original) and Figure 2B (enlarged) demonstrate the XRD pattern of crystalline (+)-TBZ Form 2 (crystalline (+)-TBZ (free base), Form 2) obtained by Chiral Resolution II. The characteristic peaks of crystalline (+)-TBZ Form 2 are summarized in Table 3. The unexpected absence of at least eleven significant peaks at 2-theta angles of 6.48°, 14.13°, 15.00°, 21.96°, 22.51°, 24.76°, 25.16°, 26.19°, 31.09°, 32.31°, and 39.92° compared to crystalline (+)-TBZ Form 1 disclosed in Example 2. The crystalline (+)-TBZ (free base, Form 2) obtained in Example 3 was used as raw material for subsequent examples of this application.

[0042] Table 3. List of characteristic peaks: crystalline (+)-TBZ, Form 2 [Table 3]

[0043] Example 4. Crystallization Method I: Crystallization by Antisolvent Addition The inventors of the present application have found that crystallization of (+)-TBZ can be achieved by dropwise dosing of an antisolvent into a (+)-TBZ stock solution. The morphology and size of the crystals can be influenced by several factors, including the concentration of the (+)-TBZ stock solution, the type of solvent and antisolvent, the dosing rate, the ratio of solvent to antisolvent, the stirring speed, the temperature, and the use of a seeding procedure. In this example, 1.5 g of (+)-TBZ was dissolved in 50 mL of ethanol to form a clear solution. Then, 50 mL of deionized (DI) water was introduced dropwise into the solution as an antisolvent at 1 mL / min while stirring with an overhead stirrer (IKA, EUROSTAR 40 DIGITAL) at 800 rpm while maintaining the temperature at 30° C. Under this condition, shorter rod-like crystals were produced (FIG. 3A), but by adding the same amount of water twice in succession to the same solution, the crystals transitioned to much longer rods with a larger aspect ratio (FIG. 3B). XRD was obtained using a Bruker D2 Phaser XPRD analyzer A26-X1-A2B0B2A0 (serial number: 209872, Germany) equipped with a Cu anode. The divergence slit and anti-scatter slit were set as 0.2 mm and 1.0 mm, respectively, and XRD confirmed that the crystals obtained in this example were Form 2.

[0044] Example 5. Crystallization Method II: Antisolvent Addition Using Polyvinylpyrrolidone 1.375 g of (+)-TBZ was dissolved in 50 mL of ethanol at 30 °C in a water bath using an overhead stirrer (IKA, EUROSTAR 40 DIGITAL) set at 800 rpm. After making the (+)-TBZ ethanol solution and stabilizing the temperature at 30 °C, 30 mL of 1% polyvinylpyrrolidone (PVP) aqueous solution (antisolvent) was added at a dropwise (by syringe pump) rate of 1 mL / min while stirring at 800 rpm. Each drop of antisolvent created a local supersaturation leading to nucleation, but was instantly resolubilized and clear. After the addition of 30 mL of antisolvent, the solution was kept stirring at 800 rpm for 30 min at 30 °C. During this process, the solution was clear without any visible nuclei. Then, 10 mL of antisolvent was again dosed at a dropwise rate of 1 mL / min while stirring at 800 rpm at 30 °C. During this dosing process, the formed nuclei were resolubilized more slowly, eventually resulting in the formation of stable (+)-TBZ seeds. The seeded (+)-TBZ suspension was allowed to grow for an additional 60 min at 30° C. with stirring. During that time, nucleation and crystal growth became progressively faster. After this crystal growth stage, 90 mL of antisolvent was again added in three portions (30 mL each) at a (drop-wise) rate of 1 mL / min, while stirring at 800 rpm at 30° C. After each portion was introduced, the solution was stirred constantly for 30 min to allow crystal growth before adding another portion of antisolvent. After the final 30 min crystal growth stage, crystallization was complete and the crystals were collected by filtration and dried (37° C.). The yield was about 90%. The crystals produced by this procedure were much easier to disperse (FIG. 4) and were confirmed to be Form 2 by XRD. The process was robust and reproducible with D10 / D50 / D90 of approximately 42.2 / 71.9 / 116 μm (Malvern, Mastersizer 3000E).

[0045] Example 6. Crystallization Method III: Size Control of (+)-TBZ Crystals The present application also enables the production of crystalline (+)-TBZ in various size ranges in a controllable manner. Adjustable parameters for controlling size during crystalline (+)-TBZ production include, but are not limited to, control over process temperature, control over API stock solution / antisolvent feed rate, and control over solvent / antisolvent ratio. For example, this can be achieved by controlling crystallization at a specific temperature. A continuous two-step process was introduced, which includes a first seeding step followed by a second nucleation / crystal growth step.

[0046] In one example, the seeding process was carried out by dissolving 1 g (+)-TBZ in 50 mL of ethanol as the first (+)-TBZ stock solution, and adding 40 mL of deionized (DI) water (as antisolvent) dropwise to this solution at a rate of 1 mL / min with 300 rpm stirring (IKA, EUROSTAR 40 DIGITAL), and the whole process was controlled at 30° C. Meanwhile, a second (+)-TBZ stock solution was prepared by dissolving 10 g (+)-TBZ in 50 mL of N-methyl-2-pyrrolidone (NMP) to continue the process for the nucleation / crystal growth stage. After the seeding process (after the addition of the first API stock solution), further nucleation and crystal growth occurred while simultaneously introducing 50 mL of the second (+)-TBZ stock solution and 50 mL of deionized (DI) water into the seeding solution at a rate of 1 mL / min with 300 rpm stirring (IKA, EUROSTAR 40 DIGITAL). The entire process was controlled at 30 °C. After completion of the crystallization process, the obtained crystals were washed several times with deionized (DI) water and then collected by filtration through a 0.2 μm filter cup and dried in an oven at 37 °C overnight. The yield was about 75-80%. The crystals produced by this method were easy to disperse. The entire process was robust and reproducible and could be performed within 2 h (Figure 5A).

[0047] In another example, the system temperature was lowered to 5°C with some adjustments for the seeding process. 400mg (+)-TBZ was dissolved in 50mL ethanol as the first API stock solution. 30mL deionized (DI) water (as antisolvent) was added dropwise to the first API stock solution at a rate of 1mL / min with 300rpm stirring (IKA, EUROSTAR 40 DIGITAL). The whole process was controlled at 5°C. Meanwhile, the second API stock solution was prepared by dissolving 10g (+)-TBZ in 50mL NMP. After the seeding process, further nucleation and crystal growth occurred after 55mL of the second (+)-TBZ stock solution and additional 55mL of deionized (DI) water were simultaneously dosed into the seeding solution at a rate of 1mL / min with 300rpm stirring (IKA, EUROSTAR 40 DIGITAL). The whole process was controlled at 5°C. After completion of the crystallization process, the resulting crystals were washed several times with deionized (DI) water and then collected by filtration through a 0.2 μm filter cup and subsequently dried in an oven at 37° C. Smaller crystals were produced in approximately 85% yield (FIG. 5B).

[0048] In yet another example, the initial amount of (+)-TBZ for the seeding process was reduced to 300 mg and the temperature throughout the process was further reduced to −5 °C, while the parameters for the subsequent nucleation / crystal growth process were kept the same. Even smaller crystals could be produced with a yield of about 85% (Figure 5C). All crystals obtained in this example were confirmed by XRD to be Form 2. The particle size analysis results of Form 2 (+)-TBZ crystals prepared under different temperature conditions using a Malvern Mastersizer 3000 are summarized in Figure 6 and Table 4.

[0049] Table 4. Summary of PSD of (+)-TBZ crystals of form 2 prepared at different temperatures. [Table 4]

[0050] Example 7. Crystallization Method IV: Scale-up of the antisolvent addition process The present application also enables the scale-up production of (+)-TBZ crystals with uniform particle size distribution in a controllable manner. In one example, a 10 gram batch production was started with the first seeding stage controlled at 20°C with 300 rpm agitation. This was done by dissolving 200 mg (+)-TBZ in 50 mL EtOH as the first API stock solution. Then, 30 mL of deionized (DI) water was filled into a polypropylene syringe (antisolvent) and fed dropwise into the first API stock solution at a rate of 1 mL / min by a syringe pump. In the second stage, nucleation and crystal growth (controlled at 20°C and 300 rpm agitation) proceeded by dissolving 10 g (+)-TBZ in 50 mL NMP as the second API stock solution. Then, about 110 mL of deionized (DI) water was filled into another polypropylene syringe as antisolvent, after which the second API stock solution and the antisolvent were fed simultaneously at a rate of 1 mL / min and 2 mL / min, respectively, by a syringe pump. Upon completion, the crystals were washed with 1 L of deionized (DI) water and collected by filtration (0.45 μm nylon filter) before drying in an oven overnight at 40° C. The crystals were examined using both a Malvern particle sizer and an optical microscope to confirm particle shape / size and size distribution (D10 / D50 / D90: 50 / 85 / 140 μm) (FIGS. 7A and 7C).

[0051] In another example, a 20 gram batch production was started with the first seeding stage controlled at 10°C with 300 rpm agitation. This was done by dissolving 800 mg (+)-TBZ in 100 mL EtOH as the first API stock solution. Then, 60 mL of deionized (DI) water was filled into a polypropylene syringe (antisolvent) and fed dropwise into the first API stock solution at a rate of 2.5 mL / min by a syringe pump. In the second stage nucleation and crystal growth, 20 g (+)-TBZ was dissolved in 100 mL NMP as the second API stock solution after keeping the system temperature the same at 10°C with 300 rpm agitation. Then, about 110 mL of deionized (DI) water was filled into another polypropylene syringe as antisolvent, after which the second API stock solution and the antisolvent were fed simultaneously at a rate of 2.5 mL / min by a syringe pump. Upon completion, the crystals were washed with 1 L of deionized (DI) water and collected by filtration (0.45 μm nylon filter) before drying in an oven overnight at 40° C. The resulting crystalline (+)-TBZ was examined using both a Malvern particle sizer and optical microscope to confirm the particle shape / size (FIG. 7B) and size distribution (D10 / D50 / D90: 50 / 85 / 130 μm, FIG. 7C). All crystals obtained in this example were confirmed to be Form 2 by XRD.

[0052] Example 8. Crystallization Method V: Crystallization by Cooling: 3 Gram Batch Three grams of (+)-TBZ were dissolved in 20 mL of ethanol at about 63 °C in a 120 mL glass vial with moderate mixing. As soon as the solution became clear and free of solid particles, the temperature of the solution was cooled at a rate of about 2 °C / min by connecting a glass double-walled jacket with a water circulation cooler. The solution was kept stirring at 200 rpm. At about 42-45 °C, a white precipitate started to be observed and the suspension was maintained at this temperature for 1 h. After this isothermal section, the temperature of the (+)-TBZ suspension was reduced to 5 °C at a rate of 10 °C / 50 min, followed by a temperature gradient of 4 °C / 10 min. Before collection, the (+)-TBZ suspension was equilibrated at 5 °C for 2 h, then filtered and dried at room temperature. The yield was about 80%. The configuration of the cooling chamber is depicted in Figure 8. The operating parameters summarized in Table 5 and Figure 8 are merely illustrative for the preparation of crystalline (+)-TBZ by the cooling method; one skilled in the art should be able to obtain the desired crystalline (+)-TBZ by following or modifying the setup and parameters accordingly. The morphology of crystalline (+)-TBZ was confirmed under a microscope (Figure 9) and the PSD of crystalline (+)-TBZ was characterized by a Malvern Master Sizer 3000E (Table 6). The crystals obtained in this example were confirmed to be Form 2 by XRD.

[0053] Table 5. Operating parameters for cooling crystallization of 3 g of (+)-TBZ. [Table 5]

[0054] Table 6. PSD of crystalline (+)-TBZ in form 2 obtained by cooling process [Table 6]

[0055] Example 9. Crystallization Method VI: Crystallization by Cooling: 12 Gram Batch Twelve grams of TBZ was dissolved in 80 mL of heated ethanol at about 63 °C in a 120 mL glass vial with moderate mixing. As soon as the solution became clear and free of solid particles, the temperature of the solution was cooled at a rate of about 2 °C / min by connecting a glass double-walled jacket with a water circulation cooler. The solution was kept stirring at 200 rpm. At about 42-45 °C, a white precipitate started to be observed and the suspension was maintained at this temperature for 1 h. After this isothermal section, the temperature of the (+)-TBZ suspension was reduced to 5 °C at a rate of 10 °C / 50 min, followed by a temperature gradient of 4 °C / 10 min. Before collection, the (+)-TBZ suspension was equilibrated at 5 °C for 2 h, then filtered and dried at room temperature. The yield was about 90%. The configuration of the cooling chamber is depicted in Figure 8. The operating parameters are summarized in Table 7. The morphology of crystalline (+)-TBZ was confirmed under a microscope (Figure 10) and the PSD of crystalline (+)-TBZ was characterized by a Malvern Master Sizer 3000E (Table 8). The crystals obtained in this example were confirmed to be Form 2 by XRD.

[0056] Table 7. Operating parameters for cooling crystallization of 12 g of (+)-TBZ stirred at 200 rpm. [Table 7]

[0057] Table 8. PSD of crystalline (+)-TBZ in Form 2 obtained by cooling process with stirring at 200 rpm on a 12 g scale [Table 8]

[0058] Example 10. Crystallization Method VII: Crystallization by Cooling at Different Mixing Rates Twelve grams of (+)-TBZ were dissolved in 80 mL of heated ethanol at about 63° C. in a 120 mL glass vial with moderate mixing. As soon as the solution became clear and free of solid particles, the temperature of the solution was cooled at a rate of about 2° C. / min by connecting a glass double-walled jacket with a water circulation condenser. The solution was kept stirring at 500 rpm. At about 42-45° C., a white precipitate started to be observed and the suspension was maintained at this temperature for 1 h. After this isothermal section, the temperature of the (+)-TBZ suspension was reduced to 5° C. at a rate of 0.2° C. / 50 min, followed by a temperature gradient of 0.4° C. / 10 min. Before collection, the (+)-TBZ suspension was equilibrated at 5° C. for 2 h, then filtered and dried at room temperature. The yield was about 90%. The cooling chamber configuration was identical to that depicted in FIG. 8. The operating parameters are summarized in Table 9. The morphology of crystalline (+)-TBZ was confirmed under a microscope (Figure 11) and the PSD of crystalline (+)-TBZ was characterized by a Malvern Master Sizer 3000E (Table 10). The crystals obtained in this example were confirmed to be Form 2 by XRD.

[0059] Table 9. Operating parameters for crystallization of 12 g of (+)-TBZ: stirring at 500 rpm [Table 9]

[0060] Table 10. PSD of crystalline (+)-TBZ in Form 2 obtained by cooling process with stirring at 500 rpm on a 12 g scale [Table 10]

[0061] Example 11. Crystallization of (+)-TBZ: Improved flowability The present application allows for the production of crystalline (+)-TBZ in a variety of particle size ranges and crystal morphologies (e.g., rod-shaped crystals and more symmetrical crystals). Since flowability of API powders / crystals can be critical in drug product manufacturing, the flow properties of the present application's crystalline (+)-TBZ were investigated. The flowability categories as characterized by the USP are shown in Table 11.

[0062] Table 11. USP 1174 Powder Flow [Table 11]

[0063] Most of the Form 2 crystalline (+)-TBZ produced in this application exhibited good flow properties, while the rod-shaped crystals exhibited poorer flow properties (Table 12). It was unexpected that the crystal morphology would result in a significant difference in powder flowability, despite identical D50 values ​​of about 80 μm (angles of repose were about 35° and about 64° for highly symmetrical and rod-shaped crystalline (+)-TBZ, respectively). The crystallization method developed in this application allows for the production of crystalline (+)-TBZ particles with good flow properties over a wide range of particle sizes.

[0064] Table 12. Flow properties of crystalline (+)-TBZ in Form 2 [Table 12]

[0065] Example 12. Crystallization of (+)-TBZ with size control: Differential Scanning Calorimetry (DSC) analysis The DSC curves presented in this application were obtained using a Waters Q200 as known in the art. Sample masses ranged from about 1 to about 5 mg. Samples were scanned from 25° C. to 200° C. at 5° C. / min increments. This application allows for the production of crystalline (+)-TBZ in various particle size ranges and crystal morphologies (e.g., rod-shaped crystals and highly symmetric crystals). DSC analysis results of various Form 2 crystalline (+)-TBZ are shown in FIGS. 12A-12C. All these DSCs show an endothermic peak at 115±5° C. The sharp endothermic peaks demonstrated that these Form 2 crystalline (+)-TBZ were in good and pure crystalline form.

[0066] Example 13. Crystallization of (+)-TBZ with size control: Thermogravimetric analysis (TGA) The TGA curves presented herein were obtained using a Waters TGA 550 as known in the art. Sample masses ranged from about 5 to about 10 mg. Samples were scanned from 25° C. to 650° C. at 10° C. / min increments. Nitrogen gas was used to purge the samples at a flow rate of 25 mL / min. Samples were held in standard platinum pans with lids. The present application allows for the production of crystalline (+)-TBZ in a variety of particle size ranges and crystal morphologies (e.g., rod-shaped crystals and highly symmetric crystals). The results of the TGA analysis of various Form 2 crystalline (+)-TBZ are summarized in FIGS. 13A-13C.

[0067] Example 14. Solubility of crystalline (+)-TBZ (cooling method) and TBZ racemate 20 mg of crystalline (+)-TBZ Form 2 was dispersed in 1 ml of PBS containing 0.2% (w / v) Tween 20. This supersaturated suspension was then stirred overnight at 37°C. 0.8 ml of the previous suspension was transferred to a 1.5 mL Eppendorf centrifuge tube. Undissolved solids were sedimented using a benchtop centrifuge at 14000 rpm for 5 minutes. Solubility was measured using the assay method described below. -Equipment: Shimadzu Separations Module (LC-30AD) with Shimadzu PDA Detector (SPD-m30A). -Column: Waters Acquity UPLC BEH C18 (150 x 3.0 mm, 1.7 m) Mobile phase A: 0.5 mM ammonium acetate:ACN=1:1 -Mobile phase B: IPA -Run time: 10 minutes -Elution gradient

[0068] [Table 13]

[0069] -Flow rate: 0.3mL / min -Column temperature: 55℃ -Injection volume: 2μL -Detection: 220nm -Run time: 10 minutes -(+)-TBZ retention time: approx. 3.5 min The solubilities of Form 2 crystalline (+)-TBZ (cooling method) and TBZ racemate are summarized in Table 13. TBZ racemate showed approximately 40% lower solubility compared to Form 2 crystalline (+)-TBZ in PBS (containing 0.2% w / v Tween 20).

[0070] Table 13. Solubility of crystalline (+)-TBZ in Form 2 (cooling method) and TBZ racemate [Table 14]

[0071] Example 15. Metabolism of Form 2 (+)-TBZ and racemic TBZ in rat liver microsomes (RLM) A rat liver microsome (RLM) study was conducted to investigate the production of pharmacoactive metabolites of (+)-TBZ in Form 2 and TBZ racemate. As summarized in Table 14, (+)-TBZ in Form 2 produced comparable amounts of therapeutically active VMAT2 inhibitors, (+)-TBZ and (+)-DHTBZ, in RLMs as racemic TBZ. While commercially available treatments for hyperkinetic disorder use TBZ racemate and d6-TBZ racemate (e.g., Xenazine and Austedo), the present application demonstrates that only (+)-TBZ produces active (+)-DHTBZ and its potential to improve treatment for hyperkinetic disorder and minimize side effects by avoiding the production of inactive TBZ isoforms, such as (-)-TBZ and (-)-DHTBZ.

[0072] Table 14. Metabolism of (+)-TBZ and racemic TBZ in RLM [Table 15]

[0073] Example 16. Sustained release polymer pharmaceutical composition containing crystalline (+)-TBZ The polymer can be dissolved in one or more biocompatible solvents to form a liquid delivery vehicle for in situ depot-forming formulations. Upon contact with body fluids after injection, an insoluble implant results, followed by continuous release of the drug, controlled by diffusion and polymer degradation. Example 16 demonstrated that sustained release of (+)-TBZ can be achieved in a pharmaceutical composition comprising PLGA, Resomer RG752H (PLGA with a 75:25 lactide to glycolide ratio and carboxylic acid end groups) and NMP at the desired PLGA / NMP ratio. In one example, the polymer solution medium was first prepared by completely dissolving Resomer RG752H in NMP at a ratio of 65 / 35, 50 / 50, or 40 / 60 (w / w) using a planetary mixer (KURABO, MAZERUSTAR). Form 2 crystalline (+)-TBZ was then mixed in and thoroughly mixed to give the final homogenous formulation at a drug loading of 50% (w / w). Aliquots of the formulation (15±5 mg) were injected into 400 mL of pH 7.4 phosphate buffered saline (containing 0.2% Tween 80) at 37°C. At the designated time points, 0.5 mL of the release medium was removed for HPLC analysis to calculate the drug concentration in the release medium. The in vitro release was performed under sink conditions throughout the study. The cumulative amount of drug released was calculated at each time point. All three formulations containing Resomer RG752H / NMP in ratios of 65 / 35, 50 / 50, and 40 / 60 (w / w) showed sustained release over at least 3 weeks. After an initial burst of more or less 5%, in vitro release of about 10% and less than 25% was observed at 1 week and 3 weeks, respectively (Figure 14). Thus, the in vitro release profile of (+)-TBZ could be tailored by selecting beneficial compositions.

[0074] Example 17. Sustained-release SAIB-based pharmaceutical composition containing crystalline (+)-TBZ Sucrose acetate isobutyrate (SAIB) can be utilized as a delivery matrix for sustained drug delivery. Upon contact with body fluids after injection, SAIB creates an insoluble implant, which then allows for continuous release of the drug, controlled by diffusion. In one example, a pharmaceutical composition was prepared comprising crystalline (+)-TBZ, one or more biocompatible solvents, and SAIB for sustained release of (+)-TBZ. The SAIB-based vehicle was prepared by first heating SAIB at 60° C. for about 20 minutes to reduce its viscosity, and then mixing it with one or more biocompatible solvents, such as ethanol (EtOH) and benzyl benzoate (BB), in a SAIB-EtOH ratio of 70 / 30 (w / w) and a SAIB / EtOH / BB ratio of 70 / 25 / 5 (w / w). Crystalline (+)-TBZ Form 2 was then suspended in the above composition using a planetary mixer (KURABO, MAZERUSTAR) and mixed thoroughly for 5 min to obtain a homogenous formulation with a drug loading of 30% or 50% (w / w). Aliquots of the formulation (15±5 mg) were injected into 400 mL of pH 7.4 phosphate buffered saline (containing 0.2% Tween 80) at 37°C. At pre-determined time points, 0.5 mL of the release medium was removed for HPLC analysis to calculate the drug concentration in the release medium. The in vitro release was performed under sink conditions throughout the study. The cumulative amount of drug released was calculated at each time point. Figure 15 shows the cumulative release of (+)-TBZ in different SAIB solution formulations over time. As shown in Figure 15, an initial burst of less than 5% was observed for selected crystalline (+)-TBZ-SAIB suspensions. The cumulative drug release over one week was between 10-25%, depending on the composition and drug loading of the selected formulation. Thus, the in vitro release profile of (+)-TBZ could be tailored by selecting beneficial compositions.

[0075] It will be apparent to those skilled in the art that modifications may be made to the above-described embodiments without departing from the broad inventive concept thereof. It is understood, therefore, that the invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications which are within the spirit and scope of the invention as defined by this description.

Claims

1. A crystalline form of (+)-tetrabenazine having an X-ray diffraction spectrum containing peaks at diffraction 2θ angles of 8.6±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 22.6±0.2°, and 23.1±0.2°.

2. 2. The crystalline form of (+)-tetrabenazine according to claim 1, which is Form 1 having an X-ray diffraction spectrum comprising peaks at diffraction 2θ angles of 6.5±0.2°, 8.6±0.2°, 12.1±0.2°, 14.1±0.2°, 15.0±0.2°, 16.5±0.2°, 17.3±0.2°, 17.9±0.2°, 22.6±0.2°, and 23.1±0.2°.

3. 3. A crystalline form of (+)-tetrabenazine according to claim 1 or 2, which is Form 1 having an X-ray diffraction spectrum substantially as shown in Figure 1A or Figure 1B.

4. 2. The crystalline form of (+)-tetrabenazine according to claim 1, which is Form 2 having an X-ray diffraction spectrum comprising peaks at diffraction 2θ angles of 8.6±0.2°, 12.1±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 17.9±0.2°, 22.6±0.2°, and 23.1±0.2°.

5. 5. A crystalline form of (+)-tetrabenazine according to claim 1 or 4, which is Form 2 having an X-ray diffraction spectrum substantially as shown in Figure 2A or Figure 2B.

6. 5. A crystalline form of (+)-tetrabenazine according to claim 1 or 4, which is Form 2 having a differential scanning calorimetry scan spectrum comprising an endothermic peak at 115±5°C.

7. 10. The crystalline form of (+)-tetrabenazine according to claim 1 or 4, which is Form 2 having a thermogravimetric analysis profile substantially as shown in Figure 13A or Figure 13B or Figure 13C.

8. 5. The crystalline form of (+)-tetrabenazine according to claim 1 or 4, which is Form 2 having a D50 particle size in the range of 1 μm to 200 μm, more preferably in the range of 5 μm to 150 μm, more preferably in the range of 10 μm to 100 μm.

9. 1. A process for producing a crystalline form of (+)-tetrabenazine having an X-ray diffraction spectrum comprising peaks at diffraction 2θ angles of 8.6±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 22.6±0.2° and 23.1±0.2°, said process comprising the step of crystallizing (+)-tetrabenazine from a solvent selected from the group consisting of isopropyl alcohol (IPA), ethanol, acetone, ethyl acetate (EA), isopropyl acetate (IPAc), methyl tert-butyl ether (MTBE), N-methyl-2-pyrrolidone (NMP), water, mixtures or combinations thereof.

10. 10. The process of claim 9, wherein the crystalline form is Form 2 having an X-ray diffraction spectrum comprising peaks at diffraction 2θ angles of 8.6±0.2°, 12.1±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 17.9±0.2°, 22.6±0.2°, and 23.1±0.2°.

11. 11. The process of claim 9 or 10, wherein the (+)-tetrabenazine is crystallized at a temperature of from -15°C to 40°C.

12. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a crystalline form of (+)-tetrabenazine having an X-ray diffraction spectrum containing peaks at diffraction 2θ angles of 8.6±0.2°, 14.1±0.2°, 15.0±0.2°, 17.3±0.2°, 22.6±0.2° and 23.1±0.

2.

13. 13. The pharmaceutical composition of claim 12, wherein the crystalline form is Form 1 having an X-ray diffraction spectrum comprising peaks at diffraction 2θ angles of 6.5±0.2°, 8.6±0.2°, 12.1±0.2°, 14.1±0.2°, 15.0±0.2°, 16.5±0.2°, 17.3±0.2°, 17.9±0.2°, 22.6±0.2°, and 23.1±0.2°.

14. 14. The pharmaceutical composition of claim 12 or 13, wherein the pharmaceutically acceptable carrier comprises a biodegradable polymer selected from the group consisting of homopolymer polylactide or polylactic acid (PLA), copolymer poly(lactic-co-glycolic acid) or poly(lactide-co-glycolide) (PLGA), and combinations thereof, preferably wherein the PLGA has a lactide:glycolide (or lactic acid:glycolic acid) monomer ratio of between 50:50 and 99:1, inclusive.

15. 15. The pharmaceutical composition of claim 14, wherein the pharmaceutically acceptable carrier further comprises a pharmaceutically acceptable organic solvent selected from the group consisting of N-methyl-2-pyrrolidone, 2-pyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, benzyl alcohol, benzyl benzoate, triacetin, and combinations thereof.

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