CRYSTALLINE FORM OF y-AMINOBUTYRIC ACID ANALOG

Abstract

A crystalline form of a γ-aminobutyric acid analog, and methods of preparing same, are provided.

1 . Unsolvated crystalline 1-{[(α-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid. 
     
     
         2 . The crystal of  claim 1  corresponding to the representative X-ray powder diffraction pattern of  FIG. 1  in an X-ray powder diffractogram using Cu Kα radiation. 
     
     
         3 . The crystal of  claim 1  having an X-ray powder diffraction pattern comprising peaks at 7.0, 16.4 and 17.9±0.3 degrees 2Ξ in an X-ray powder diffractogram using Cu Kα radiation. 
     
     
         4 . The crystal of  claim 3  further comprising peaks at 8.2, 10.5, 18.9, 20.9 and 23.3±0.3 degrees 2θ in an X-ray powder diffractogram using Cu Kα radiation. 
     
     
         5 . The crystal of  claim 1  corresponding to the representative thermogravimetric analysis thermogram of  FIG. 2 . 
     
     
         6 . The crystal of  claim 1  having a differential scanning calorimetry thermogram comprising an exotherm with a maximum at 63±2° C., as determined by a differential scanning calorimetry at a scan rate of 5°C./minute. 
     
     
         7 . A method of treating restless legs syndrome comprising administering unsolvated crystalline 1-{[(α-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid. 
     
     
         8 . A method of treating post herpetic neuralgia comprising administering unsolvated crystalline 1-{[(α-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid. 
     
     
         9 . A pharmaceutical composition comprising the unsolvated crystalline 1-{[(α-isobutanoyloxyethoxy)carbonyl]aminomethyl}-1-cyclohexane acetic acid.