Claims for Patent: 8,686,034

Summary for Patent: 8,686,034

Title:	Crystalline form of .gamma.-aminobutyric acid analog
Abstract:	A crystalline form of a .gamma.-aminobutyric acid analog, and methods of preparing same, are provided.
Inventor(s):	Estrada; Tono (Santa Clara, CA), Raillard; Stephen P. (Mountain View, CA), Frauenfelder; Christine (Glis, CH), Zacher; Uwe (Brig, CH)
Assignee:	XenoPort, Inc. (Santa Clara, CA)
Application Number:	13/164,620
Patent Claims:	1. A method of treating restless legs syndrome or post herpetic neuralgia in a patient in need of such treatment, comprising administering to the patient a therapeutically effective amount of crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 7.0.degree..+-.0.3.degree., 8.2.degree..+-.0.3.degree., 10.5.degree..+-.0.3.degree., 12.8.degree..+-.0.3.degree., 14.9.degree..+-.0.3.degree. and 16.4.degree..+-.0.3.degree. in an X-ray powder diffractogram using Cu K.alpha. radiation. 2. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 17.9.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 3. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 18.1.degree..+-.0.3 in the X-ray powder diffractogram using Cu K.alpha. radiation. 4. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 18.9.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 5. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 20.9.degree.=0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 6. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 23.3.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 7. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 25.3.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 8. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 9. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 17.9.degree..+-.0.30, 18.9.degree..+-.0.3.degree., 20.9.degree..+-.0.3.degree., 23.3.degree..+-.0.3.degree., 25.3.degree..+-.0.3, and 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 10. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 18.1.degree..+-.0.3.degree., 18.9.degree..+-.0.3.degree., 20.9.degree..+-.0.3.degree., 23.3.degree..+-.0.3.degree., 25.3.degree..+-.0.3.degree., and 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 11. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 17.9.degree..+-.0.3.degree., 18.1.degree..+-.0.3.degree., 18.9.degree..+-.0.3.degree., 20.9.degree..+-.0.3.degree., 23.3.degree..+-.0.3.degree., 25.3.degree..+-.0.3.degree., and 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 12. The method of claim 1, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a melting point range of between 63.degree. C. and 64.degree. C. as determined by differential scanning calorimetry at a scan rate of 5.degree. C./minute. 13. The method of claim 1, wherein the method treats post herpetic neuralgia. 14. The method of claim 1, wherein the method treats restless legs syndrome. 15. A method of treating restless legs syndrome or post herpetic neuralgia in a patient in need of such treatment, comprising administering to the patient a pharmaceutical composition comprising a therapeutically effective amount of crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid and a pharmaceutically acceptable vehicle, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 7.0.degree..+-.0.3.degree., 8.2.degree..+-.0.3.degree., 10.5.degree..+-.0.3.degree., 12.8.degree..+-.0.3.degree., 14.9.degree..+-.0.3.degree. and 16.4.degree..+-.0.3.degree. in an X-ray powder diffractogram using Cu K.alpha. radiation. 16. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 7.9.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 17. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 18.1.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 18. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 18.9.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 19. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 20.9.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 20. The method of claim, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 23.3.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 21. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 25.3.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 22. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a characteristic absorption peak at 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 23. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 17.9.degree..+-.0.3.degree., 18.9.degree..+-.0.3.degree., 20.9.degree..+-.0.3.degree., 23.3.degree..+-.0.3.degree., 25.3.degree..+-.0.3.degree., and 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 24. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 18.1.degree..+-.0.3.degree., 18.9.degree..+-.0.3.degree., 20.9.degree..+-.0.3.degree., 23.3.degree..+-.0.3.degree., 25.3.degree..+-.0.3.degree., and 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 25. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has characteristic absorption peaks at 17.9.degree..+-.0.3.degree., 18.1.degree..+-.0.3.degree., 18.9.degree..+-.0.3.degree., 20.9.degree..+-.0.3.degree., 23.3.degree..+-.0.3.degree., 25.3.degree..+-.0.3.degree., and 26.6.degree..+-.0.3.degree. in the X-ray powder diffractogram using Cu K.alpha. radiation. 26. The method of claim 15, wherein the crystalline 1-{[(.alpha.-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid has a melting point range of between 63.degree. C. and 64.degree. C. as determined by differential scanning calorimetry at a scan rate of 5.degree. C./minute. 27. The method of claim 15, wherein the method treats post herpetic neuralgia. 28. The method of claim 27, wherein the pharmaceutical composition is an oral sustained release system. 29. The method of claim 15, wherein the method treats restless legs syndrome. 30. The method of claim 29, wherein the pharmaceutical composition is an oral sustained release system.