Pharmaceutical compositions
The invention provides (+)-α-dihydrotetrabenazine succinate salt. Also provided are (+)-α-dihydrotetrabenazine succinate salt for use in medicine, pharmaceutical compositions comprising (+)-α-dihydrotetrabenazine succinate salt and a pharmaceutically acceptable excipient and the uses of (+)-α-dihydrotetrabenazine succinate salt as a VMAT2 receptor antagonist and in the treatment of a movement disorder such as Tourette's syndrome. The invention further provides a method for preparing the (+)-α-dihydrotetrabenazine succinate salt.
1. A method of treatment of a movement disorder in a subject in need thereof, which method comprises administering to the subject a therapeutically effective amount of (+)-α-dihydrotetrabenazine succinate.
2. A method according to claim 1 wherein the movement disorder is a hyperkinetic movement disorder.
3. A method according to claim 2 wherein the hyperkinetic movement disorder is selected from Huntington's disease, hemiballismus, senile chorea, tic disorders, tardive dyskinesia, dystonia and Tourette's syndrome.
4. A method according to claim 3 wherein the hyperkinetic movement disorder is Tourette's syndrome.
5. A method according to claim 1 wherein the subject is a mammalian subject.
6. A method according to claim 5 wherein the subject is a human.
7. A method according to claim 1 wherein the treatment comprises administering to the subject an amount of (+)-α-dihydrotetrabenazine succinate between 1 mg and 30 mg per day.
8. A method according to claim 7 wherein the treatment comprises administering to the subject an amount of (+)-α-dihydrotetrabenazine succinate between 2 mg and 20 mg per day.
9. A method according to claim 1 wherein the (+)-α-dihydrotetrabenazine succinate salt is in a crystalline form.
10. A method according to claim 1 wherein the (+)-α-dihydrotetrabenazine succinate salt has a salt ratio of approximately 1:1.
11. A method according to claim 1 wherein the (+)-α-dihydrotetrabenazine succinate salt is in a substantially crystalline form having an X-ray powder diffraction pattern characterized by the presence of major peaks at the diffraction angles of approximately 9.2° and/or 10.0° and/or 18.5° and/or 22.4°.
12. A method according to claim 1 wherein the (+)-α-dihydrotetrabenazine succinate salt is in a substantially crystalline form having an X-ray powder diffraction pattern substantially as shown in any of plots ZEN-E-6-7b, LYO-F-4(3), SUN-AJ-163(2) or SUN-AJ-163(2) AD in FIG. 1 .
13. A method according to claim 1 wherein the (+)-α-dihydrotetrabenazine succinate salt is in a substantially crystalline form having an X-ray powder diffraction pattern substantially as shown in plot SUN-AJ-163(2) in FIG. 1 .
14. A method according to claim 10 wherein the movement disorder is a hyperkinetic movement disorder.
15. A method according to claim 14 wherein the hyperkinetic movement disorder is selected from Huntington's disease, hemiballismus, senile chorea, tic disorders, tardive dyskinesia, dystonia and Tourette's syndrome.
16. A method according to claim 15 wherein the hyperkinetic movement disorder is Tourette's syndrome.