DESC:The following specification particularly describes the invention and the manner in which it is to be performed.

INTRODUCTION
Aspects of the present application relates to crystalline forms of salts of Deutetrabenazine, process for the preparation thereof and pharmaceutical composition of crystalline forms of salts.
Deutetrabenazine or d6-tetrabenazine is a deuterated analog of tetrabenazine. The drug compound having the adopted name “Deutetrabenazine” has chemical name: (RR, SS)-1, 3, 4, 6, 7, 11b-hexahydro-9, 10-di(methoxy-d3)-3-(2-methylpropyl)-2H-benzo[a]quinolizin-2-one. Deutetrabenazine is a racemic mixture containing the following structures:

RR-Deutetrabenazine SS-Deutetrabenazine
AUSTEDOTM (Deutetrabenazine) is a vesicular monoamine transporter 2 (VMAT2) inhibitor for oral administration. AUSTEDOTM was approved as oral tablets (6 mg, 9 mg, and 12 mg) by USFDA on 3 April 2017 for the treatment of chorea associated with Huntington’s disease. In August 2017 it was also approved for the treatment of tardive dyskinesia in adults.
US8524733B1 discloses Deutetrabenazine or a pharmaceutically acceptable salt thereof, method for the treatment of chronic hyperkinetic movement disorders and pharmaceutical composition thereof.
US9550780B2 discloses crystalline Form I and crystalline Form II of Deutetrabenazine.
WO2017221169A1 discloses premixes of deutetrabenazine with polyvinylpyrrolidone K-30, copovidone, talc and magnesium stearate.
The occurrence of different crystal forms, i.e., polymorphism, is a property of some compounds. A single molecule may give rise to a variety of polymorphs having distinct crystal structures and physical properties, such as PXRD patterns, IR absorption spectra, melting points (MP), TGA curves, DSC curves, and solubilities. Polymorphs are different solids having the same molecular structure, yet having distinct physical properties when compared to other polymorphs of the same structure.
The discovery of new polymorphs and solvates of a pharmaceutical active compound provides an opportunity to improve the performance of a drug product in terms of its bioavailability or release profile in vivo, or it may have improved stability or advantageous handling properties. Polymorphism is an unpredictable property of any given compound. This subject has been reviewed in recent articles, including A. Goho, “Tricky Business,” Science News, August 21, 2004. In general, one cannot predict whether there will be more than one form for a compound, how many forms will eventually be discovered, or how to prepare any previously unidentified form.
There remains a need to provide the new polymorphic forms of Deutetrabenazine which can be used in the pharmaceutical composition.

SUMMARY OF THE INVENTION
The present application provides crystalline forms of Deutetrabenazine salts and process for preparing said crystalline forms and pharmaceutical composition comprising said crystalline forms.

The present application also provides Succinic acid salt of Deutetrabenazine and process of preparing and pharmaceutical composition comprising said salt.

The present application provides Fumaric acid of Deutetrabenazine and process of preparing and pharmaceutical composition comprising said salt.

The present application also provides process for the preparation of crystalline form SD1 of Deutetrabenazine.

BRIEF DESCRIPTION OF THE DRAWING
Figure 1 illustrates a characteristic PXRD pattern of crystalline Deutetrabenazine form SD4.
Figure 2 illustrates a characteristic PXRD pattern of Succinic acid salt of Deutetrabenazine referred as Form SD5.
Figure 3 illustrates a characteristic PXRD pattern of Fumaric acid of Deutetrabenazine referred as Form SD6a.
Figure 4 illustrates a characteristic PXRD pattern of Fumaric acid of Deutetrabenazine referred as Form SD6b.
Figure 5 illustrates a characteristic PXRD pattern of Fumaric acid of Deutetrabenazine referred as Form SD6c.
Figure 6 illustrates a characteristic PXRD pattern of Fumaric acid of Deutetrabenazine referred as Form SD6d.
Figure 7 illustrates a characteristic PXRD pattern of crystalline Deutetrabenazine form SD1.

DETAILED DESCRIPTION
In one aspect, the application provides a crystalline form of Deutetrabenazine, herein designated as Form SD4, characterized by a PXRD pattern having X-ray powder diffraction peaks selected from the following at about 5.62° and 10.31°± 0.2° 2?. The crystalline Form SD4 may be further characterized by X-ray powder diffraction peaks at about 11.50° and 20.66°± 0.2° 2?. PXRD pattern of crystalline form SD4 of Deutetrabenazine is substantially depicted in FIG.1. The crystalline Form SD4 of Deutetrabenazine may be acetic acid solvate.
Further during studies the inventors found this crystalline form herein designated as Form SD4 as acetic acid salt of Deutetrabenazine in place of acetic acid solvate.
In another aspect, the present application provides a process for the preparation of crystalline form SD4 of Deutetrabenazine, characterized by a PXRD pattern having peaks at about 5.62° and 10.31°± 0.2° 2?.; comprising,
a) providing the solution of Deutetrabenazine in acetic acid;
b) cooling the solution obtained in step (a); and
c) isolating the crystalline form SD4 of Deutetrabenazine
In embodiments, Deutetrabenazine can be dissolved in acetic acid to provide a solution.
In an embodiment, the precipitation of crystalline form SD4 of Deutetrabenazine can be obtained by cooling the solution obtained in step a). In embodiments, the solution obtained in step a) can be cooled to room temperature to -10°C. In embodiments, the slurry comprising precipitated crystalline form SD4 of Deutetrabenazine can be maintained at any suitable temperatures, such as from about room temperature to about 0°C. In embodiments, the slurry comprising precipitated crystalline form SD4 of Deutetrabenazine can be maintained for about 10 minutes to about 10 hours, or longer.
In embodiments, crystalline Form SD4 of Deutetrabenazine can be isolated using any techniques, such as decantation, filtration by gravity or suction, centrifugation, or the solvent can be evaporated from the mass to obtain the desired product, and optionally the solid can be washed with a solvent, such as the solvent used for the crystallization to reduce the amount of entrained impurities in the product. In embodiments, crystalline form SD4 of Deutetrabenazine can be isolated by filtration.
In embodiments, crystalline form SD4 of Deutetrabenazine that is isolated may be dried at suitable temperatures such as room temperature to about 80°C under atmospheric or reduced pressures, for about 10 minutes to about 50 hours, or longer, using any types of drying equipment, such as a tray dryer, vacuum oven, air oven, fluidized bed dryer, spin flash dryer, flash dryer, or the like.
In another aspect, the present application provides a process for the preparation of crystalline form SD4 of Deutetrabenazine, characterized by a PXRD pattern having peaks at about 5.62° and 10.31°± 0.2° 2?.; comprising,
a) providing the solution of Deutetrabenazine in acetic acid;
b) adding the anti-solvent to the solution obtained in step (a); and
c) isolating the crystalline form SD4 of Deutetrabenazine
In embodiments of step a), Deutetrabenazine can be dissolved in acetic acid to provide a solution.
In embodiment of step b), anti-solvent is added to solution obtained in step a). The anti-solvent can be a solvent in which Deutetrabenazine is insoluble or having very poor solubility. In embodiments the anti-solvent can be ether, alkanes, cycloalkanes or mixtures thereof. In embodiments the anti-solvent can be a mixture of Methyl Tert Butyl Ether and n-Heptane. In embodiments both anti-solvents can be added together or simultaneously. In embodiments Methyl Tert Butyl Ether was added first to the solution of step a) followed by addition of n-Heptane. In embodiments the ratio of solvent to anti-solvents can be in the range of 1:5 to 1:100 or preferably 1:5 to 1: 50 or any suitable combination. In embodiments the ratio of anti-solvents Methyl Tert Butyl Ether and n-Heptane can be in the range of 1:1 to1:10 or any suitable combination.
In an embodiment, the precipitation of crystalline form SD4 of Deutetrabenazine can be obtained by cooling the solution or suspension obtained in step b). In embodiments, the solution or suspension obtained in step b) can be cooled to room temperature to -10°C. In embodiments, the slurry comprising precipitated crystalline form SD4 of Deutetrabenazine can be maintained at any suitable temperatures, such as from about room temperature to about 0°C. In embodiments, the slurry comprising precipitated crystalline form SD4 of Deutetrabenazine can be maintained for about 10 minutes to about 10 hours, or longer.
In embodiments, crystalline Form SD4 of Deutetrabenazine can be isolated using any techniques, such as decantation, filtration by gravity or suction, centrifugation, or the solvent can be evaporated from the mass to obtain the desired product, and optionally the solid can be washed with a solvent, such as the solvent used for the crystallization to reduce the amount of entrained impurities in the product. In embodiments, crystalline form SD4 of Deutetrabenazine can be isolated by filtration.
Further during studies the inventors found this crystalline form herein designated as Form SD4 as acetic acid salt of Deutetrabenazine in place of acetic acid solvate.
In another aspect, the present application also provides Succinic acid salt of Deutetrabenazine and process of preparing and pharmaceutical composition comprising said salt.
In another aspect, the Succinic acid salt of Deutetrabenazine herein designated as Form SD5, characterized by a PXRD pattern having X-ray powder diffraction peaks selected from the following at about 7.98° and 11.54°± 0.2° 2?. Form SD5 may be further characterized by X-ray powder diffraction peaks at about 23.15°, 26.00° and 19.25° °± 0.2° 2?.
In another aspect, the application provides Succinic acid salt of Deutetrabenazine, characterized by an X-ray powder diffraction pattern as illustrated in Figure 2.
In another aspect, the present application provides process for the preparation of Succinic acid salt of Deutetrabenazine, comprising the steps of:
a) mixing Deutetrabenazine and Succinic acid in acetone;
b) obtaining the Succinic acid salt by grinding the mixture;
In embodiments, Deutetrabenazine and Succinic acid were added into a clean mortar and mixture was grinded by adding acetone. The Succinic acid salt was obtained as dried powder.
In embodiments of step a), any suitable solvents can also be used other than acetone. The suitable solvents can be selected from ketones, alcohols, esters, ethers, or their mixtures.
Further during studies the inventors found this co-crystal herein designated as Form SD5 as Succinic acid salt of Deutetrabenazine in place of Succinic acid co-crystal of Deutetrabenazine.
In another aspect, the application provides Fumaric acid salt of Deutetrabenazine, process of preparing and pharmaceutical composition comprising said salt.
In another aspect, the Fumaric acid salt of Deutetrabenazine herein designated as Form SD6a, characterized by a PXRD pattern having X-ray powder diffraction peaks selected from the following at about 7.59°, 10.18° and 11.40°± 0.2° 2?. Form SD6a may be further characterized by X-ray powder diffraction peaks at about 18.55° and 22.13° °± 0.2° 2?.
In another aspect, the application provides Fumaric acid salt of Deutetrabenazine and Form SD6a, characterized by an X-ray powder diffraction pattern as illustrated in Figure 3.
In another aspect, the present application provides process for the preparation of Fumaric acid salt of Deutetrabenazine and Form SD6a, comprising the steps of:
a) mixing Deutetrabenazine and Fumaric acid in acetone;
b) obtaining the Fumaric acid salt by grinding the mixture;
In embodiments, Deutetrabenazine and Fumaric acid were added into a clean mortar and mixture was grinded by adding acetone. The Fumaric acid salt was obtained as dried powder.
In embodiments of step a), any suitable solvents can also be used other than acetone. The suitable solvents can be selected from ketones, alcohols, esters, ethers, or their mixtures.
In another aspect, the Fumaric acid salt of Deutetrabenazine herein designated as Form SD6b, characterized by a PXRD pattern having X-ray powder diffraction peaks selected from the following at about 7.78° and 12.52°± 0.2° 2?. Form SD6b may be further characterized by X-ray powder diffraction peaks at about 16.73° and 18.86° °± 0.2° 2?.
In another aspect, the application provides Fumaric acid salt of Deutetrabenazine Form SD6b, characterized by an X-ray powder diffraction pattern as illustrated in Figure 4.
In another aspect, the present application provides process for the preparation of Fumaric acid salt of Deutetrabenazine Form SD6b, comprising the steps of:
a) providing solution of Deutetrabenazine and Fumaric acid in Acetone and methanol;
b) obtaining the Fumaric acid salt by slow solvent evaporation;
In embodiments, Deutetrabenazine and Fumaric acid were dissolved in mixture of acetone and methanol to obtain solution. The solution was filtered to make it particle free solution and the obtained solution is kept for slow evaporation of the solvent for obtaining the Fumaric acid salt of Deutetrabenazine and Fumaric acid Form SD6b.
In embodiments of step a), any suitable solvents can also be used other than acetone and methanol. The suitable solvents can be selected from ketones, alcohols, esters, ethers, or their mixtures.
In another aspect, the Fumaric acid salt of Deutetrabenazine herein designated as Form SD6c, characterized by a PXRD pattern having X-ray powder diffraction peaks selected from the following at about 4.77° and 7.93°± 0.2° 2?. Form SD6c may be further characterized by X-ray powder diffraction peaks at about 12.54° and 15.74° °± 0.2° 2?.
In another aspect, the application provides Fumaric acid salt of Deutetrabenazine Form SD6c, characterized by an X-ray powder diffraction pattern as illustrated in Figure 5.
In another aspect, the present application provides process for the preparation of Fumaric acid salt of Deutetrabenazine Form SD6c, comprising the steps of:
a) providing solution of Deutetrabenazine and Fumaric acid in Acetone and methanol;
b) obtaining the Fumaric acid salt by slow solvent evaporation;
In embodiments, Deutetrabenazine and Fumaric acid were dissolved in mixture of acetone and methanol to obtain solution. The solution was filtered to make it particle free solution and the obtained solution is kept for slow evaporation of the solvent for obtaining the Fumaric acid salt of Deutetrabenazine Form SD6c.
In embodiments of step a), any suitable solvents can also be used other than acetone and methanol. The suitable solvents can be selected from ketones, alcohols, esters, ethers, or their mixtures.
In another aspect, the Fumaric acid salt of Deutetrabenazine and Fumaric acid herein designated as Form SD6d, characterized by a PXRD pattern having X-ray powder diffraction peaks selected from the following at about 7.62°, 10.21° and 11.41°± 0.2° 2?. Form SD6d may be further characterized by X-ray powder diffraction peaks at about 18.61° and 22.14° °± 0.2° 2?.
In another aspect, the application provides Fumaric acid salt of Deutetrabenazine Form SD6d, characterized by an X-ray powder diffraction pattern as illustrated in Figure 6.
In another aspect, the present application provides process for the preparation of Fumaric acid salt of Deutetrabenazine Form SD6d, comprising the steps of:
c) mixing Deutetrabenazine and Fumaric acid in mixture of acetone and methanol;
d) obtaining the Fumaric acid salt by grinding the mixture;
In embodiments, Deutetrabenazine and Fumaric acid were added into a clean mortar and mixture was grinded by adding mixture of acetone and methanol. The co-crystal was obtained as dried powder.
In embodiments of step a), any suitable solvents can also be used other than acetone and methanol. The suitable solvents can be selected from ketones, alcohols, esters, ethers, or their mixtures.
Further during studies the inventors found these co-crystals herein designated as Forms SD6a, SD6b, SD6c and SD6d as Fumaric acid salt of Deutetrabenazine in place of Fumaric acid co-crystal of Deutetrabenazine.
In another aspect, the application provides a process for the preparation of crystalline form SD1 of Deutetrabenazine, characterized by a PXRD pattern having peaks at about 7.93°, 11.44° and 24.33°± 0.2° 2?; comprising,
a) Dissolving Deutetrabenazine in mixture of formic acid and n-Heptane to obtain clear solution;
b) isolating the crystalline form SD1 of Deutetrabenazine by crystallization from the solution of step a).
c) adding Syloid to form SD1 and physically mixing to get stable Form SD1 of Deutetrabenazine.
In embodiments of step a), Deutetrabenazine can be dissolved in mixture of formic acid and n-Heptane to provide a solution.
In embodiments of step a), the other anti-solvents can be a solvent in which Deutetrabenazine is insoluble or having very poor solubility. In embodiments the anti-solvent can be ether, alkanes, cycloalkanes or mixtures thereof.
In an embodiments of step b), the precipitation of crystalline form SD1 of Deutetrabenazine can be obtained by cooling the solution obtained in step a). In embodiments, the solution obtained in step a) can be cooled to room temperature to -10°C. In embodiments, the slurry comprising precipitated crystalline form SD1 of Deutetrabenazine can be maintained at any suitable temperatures, such as from about room temperature to about 0°C. In embodiments, the slurry comprising precipitated crystalline form SD1 of Deutetrabenazine can be maintained for about 10 minutes to about 10 hours, or longer.
In an embodiments of step c), Syloid(R) added to crystalline form SD1 and physically mixed to provide stable form SD1.
In an aspect, the application provides crystalline form SD1 of Deutetrabenazine, characterized by an X-ray powder diffraction pattern as illustrated in Figure 7.
Further during studies the inventors found this crystalline form herein designated as Form SD1 as formic acid salt of Deutetrabenazine in place of formic acid solvate.
In embodiments, the crystalline forms and salts of Deutetrabenazine according to the present application can be milled or micronized by any process known in the art, such as ball milling, jet milling, wet milling etc., to produce desired particle sizes and particle size distributions.
Any physical form of Deutetrabenazine may be utilized for providing the solution of Deutetrabenazine. Deutetrabenazine that may be used as the input for the process of the present invention may be obtained by the processes described in the art. For example Deutetrabenazine may be prepared by the processes described in US8524733B1, US9550780B2, WO2015084622A1, WO2011153157A2 and WO2017182916A1.
In another aspect, the present application provides a pharmaceutical composition comprising the crystalline forms and co-crystals of Deutetrabenazine as described in the present application together with at least one pharmaceutically acceptable excipient.
Further during studies the inventors found that these crystalline forms herein designated Forms SD4, SD1 are salts of corresponding acid and not the solvates and similarly the co-crystals herein designated as Forms SD5, SD6a, SD6b, SD6c and SD6d are salts of corresponding acid in place of co-crystal of Deutetrabenazine.
Pharmaceutically acceptable excipients that are useful in the present application include, but are not limited to, any one or more of: diluents such as starches, pregelatinized starches, powdered cellulose, microcrystalline cellulose, dicalcium phosphate, tricalcium phosphate, mannitol, sorbitol, sugar, or the like; binders such as acacia, guar gum, tragacanth, gelatin, polyvinylpyrrolidones, hydroxypropyl celluloses, hydroxypropyl methylcelluloses, pregelatinized starches, or the like; disintegrants such as starches, sodium starch glycolate, pregelatinized starches, crospovidones, croscarmellose sodium, colloidal silicon dioxide, or the like; lubricants such as stearic acid, magnesium stearate, zinc stearate, or the like; glidants such as colloidal silicon dioxide or the like; solubility or wetting enhancers such as anionic, cationic, and neutral surfactants; complex forming agents such as various grades of cyclodextrins and resins; and release rate controlling agents such as hydroxypropyl celluloses, hydroxymethyl celluloses, hydroxypropyl methylcelluloses, ethylcelluloses, methylcelluloses, various grades of methyl methacrylates, waxes, or the like. Other pharmaceutically acceptable excipients that are useful include, but are not limited to, film-formers, plasticizers, colorants, flavoring agents, sweeteners, viscosity enhancers, preservatives, antioxidants, or the like.
Certain specific aspects and embodiments of the present application will be explained in greater detail with reference to the following examples, which are provided only for purposes of illustration and should not be construed as limiting the scope of the application in any manner. Variations of the described procedures, as will be apparent to those skilled in the art, are intended to be within the scope of the present application.
The term "about" when used in the present application preceding a number and referring to it, is meant to designate any value which lies within the range of ±10%, preferably within a range of ±5%, more preferably within a range of ±2%, still more preferably within a range of ±1 % of its value. For example "about 10" should be construed as meaning within the range of 9 to 11, preferably within the range of 9.5 to 10.5, more preferably within the range of 9.8 to 10.2, and still more preferably within the range of 9.9 to 10.1.

General description of the PXRD equipment
X-ray diffraction was measured using PANalytical X-ray diffractometer, Model: X'Pert PRO. System description: CuK-Alpha 1 wavelength= 1 .54060, voltage 45kV, current 40 mA, divergence slit=0.5°; Sample stage=Reflection-Transmission Spinner. Scan type: Continuous; Detector - X'Celerator; Measurement parameters: Start Position [°2Th.]: 3; End Position [°2Th.]: 40; Step Size [°2Th.]:0.0167; Scan Step Time [s]: 64.770.
Syloid® silica as used in the present application is widely used in pharmaceutical preparations. SYLOID® 244 FP Silica is used in the examples of the present application. Any other grades of SYLOID can also be used.

EXAMPLES
Example-1: Preparation of crystalline form SD4 of Deutetrabenazine
Deutetrabenazine (200 mg) was dissolved in acetic acid (0.5 mL) at 70°C and stirred for 15 minutes to get clear solution. Deutetrabenazine (200 mg) was again added to the above clear solution at 70°C and stirred for 15 minutes to get clear viscous solution. Again Deutetrabenazine (150 mg) to above viscous solution at 70°C and stirred for 15 minutes. The temperature increased to 80°C to obtain clear solution under stirring. The clear solution was kept in ice bath for 1 h and then evaporated the solvent at room temperature. The crystallization of material was observed after 12 h. The product was obtained by filtration of the precipitated material.
The PXRD pattern of the isolated material is represented as Figure-1.

Example-2: Preparation of crystalline form SD4 of Deutetrabenazine
Deutetrabenazine (2 g) was dissolved in acetic acid (2 mL) at 70°C and stirred for 90 minutes to get clear solution. Methyl Tert-Butyl Ether (20 mL) and n-Heptane (80 mL) was added slowly at 25°C to the above clear solution. The solution was cooled to 0°C and stirred for 4 h. The product was obtained by filtration of the precipitated material.

Example-3: Preparation of co-crystal of Deutetrabenazine and succinic acid (SD5)
Deutetrabenazine (323.46 mg) and succinic acid (238 mg) were charged into a clean mortar at room temperature. Acetone (0.5 mL) was added to the mixture and grind for 10 minutes. Acetone (0.5 mL) was again added to the mixture and grind for 10 minutes. Acetone (1 mL) was again added to the mixture and grind for 10 minutes to obtain the co-crystal of Deutetrabenazine and succinic acid (SD5).
The PXRD pattern of the isolated material is represented as Figure-2.

Example-4: Preparation of co-crystal of Deutetrabenazine and Fumaric acid (SD6a)
Deutetrabenazine (200 mg) and Fumaric acid (72 mg) were charged into a clean mortar at room temperature. Acetone (1 mL) was added to the mixture and grind for 10 minutes. Acetone (1 mL) was again added to the mixture and grind for 10 minutes. Acetone (1 mL) was again added to the mixture and grind for 10 minutes to obtain the co-crystal of Deutetrabenazine and Fumaric acid (SD6a).
The PXRD pattern of the isolated material is represented as Figure-3.

Example-5: Preparation of co-crystal of Deutetrabenazine and Fumaric acid (SD6b)
Deutetrabenazine (500 mg) and Fumaric acid (179 mg) were dissolved in acetone (4 mL) and methanol (4 mL) at room temperature. The solution was filtered to obtain clear solution and kept for slow solvent evaporation. The crystal were observed after 3 days.
The PXRD pattern of the isolated material is represented as Figure-4.

Example-6: Preparation of co-crystal of Deutetrabenazine and Fumaric acid (SD6c)
Deutetrabenazine (500 mg) and Fumaric acid (179 mg) were dissolved in acetone (6 mL) and methanol (6 mL) at room temperature. The solution was filtered to obtain clear solution and kept for slow solvent evaporation. The crystal were observed after 3 days.
The PXRD pattern of the isolated material is represented as Figure-5.

Example-6: Preparation of co-crystal of Deutetrabenazine and Fumaric acid (SD6d)
Deutetrabenazine (325 mg) and Fumaric acid (117 mg) were charged into a clean mortar at room temperature. Acetone (1 mL) and methanol (1 mL) was added to the mixture and grind for 10 minutes. Acetone (1 mL) and methanol (1 mL) was again added to the mixture and grind for 10 minutes. Acetone (1 mL) and methanol (1 mL) was again added to the mixture and grind for 10 minutes. Acetone (1 mL) and methanol (1 mL) was again added to the mixture and grind for 10 minutes to obtain the co-crystal of Deutetrabenazine and Fumaric acid (SD6d).
The PXRD pattern of the isolated material is represented as Figure-6.

Example-7: Preparation of crystalline form SD1 of Deutetrabenazine
n-Heptane (60 mL) and Formic acid (0.3 mL) were added to the easymax reactor at room temperature and stirred for 10 minutes. The solution was cooled to 10°C. Deutetrabenazine (1 g) was charged into easymax reactor containing the solvent at 10°C and maintained for 2 h under stirring. The product was obtained by filtration of the precipitated material. Syloid (0.7 g) was added to Form SD1 and physically mixed to obtain stable Form SD1.
The PXRD pattern of the isolated material is represented as Figure-7.
,CLAIMS:We Claim:
1. Crystalline form SD4 of acetic acid salt of Deutetrabenazine characterized by an X-ray powder diffraction pattern comprising the peak at about 5.62° and 10.31°± 0.2° 2?.
2. A process for preparing crystalline Form SD4 acetic acid salt of Deutetrabenazine comprising the steps of;
a) providing the solution of Deutetrabenazine in acetic acid;
b) cooling the solution obtained in step (a); and
c) isolating the crystalline form SD4 of Deutetrabenazine
3. Crystalline form SD5 of succinic acid salt of Deutetrabenazine characterized by an X-ray powder diffraction pattern comprising the peak at about 7.98° and 11.54°± 0.2° 2?.
4. A process for preparing crystalline Form SD5 succinic acid salt of Deutetrabenazine comprising the steps of;
a) mixing Deutetrabenazine and Succinic acid in acetone;
b) obtaining the co-crystal by grinding the mixture;
5. Crystalline Form SD6a of Fumaric acid salt of Deutetrabenazine characterized by an X-ray powder diffraction pattern comprising the peak at about 7.59°, 10.18° and 11.40°± 0.2° 2?.
6. A process for preparing crystalline Form SD6a of Fumaric acid salt of Deutetrabenazine comprising the steps of;
a) mixing Deutetrabenazine and Fumaric acid in acetone;
b) obtaining the co-crystal by grinding the mixture;
7. Crystalline Form SD6b of Fumaric acid salt of Deutetrabenazine characterized by an X-ray powder diffraction pattern comprising the peak at about 7.78° and 12.52°± 0.2° 2?.
8. Crystalline Form SD6c of Fumaric acid salt of Deutetrabenazine characterized by an X-ray powder diffraction pattern comprising the peak at about 4.77° and 7.93°± 0.2° 2?.
9. Crystalline Form SD6d of Fumaric acid salt of Deutetrabenazine characterized by an X-ray powder diffraction pattern comprising the 7.62°, 10.21° and 11.41°± 0.2° 2?.
10. A pharmaceutical composition comprising the crystalline Forms of salts of Deutetrabenazine selected from Form SD4, Form SD5, SD6a, SD6b, SD6c and Form SD6d and pharmaceutically acceptable excipients.