Structural and thermal characterization of zolpidem hemitartrate hemihydrate (Form E) and its decomposition products by laboratory X-ray powder diffraction.

摘要

The crystal structure of zolpidem hemitartrate hemihydrate (I, Form E) has been solved from high-resolution laboratory powder diffraction data. It crystallizes in the orthorhombic P2(1)2(1)2(1) space group with a = 22.4664(6) A, b = 26.0420(7) A, and c = 7.4391(1) A. Protonation of zolpidem molecules could not be unambiguously determined. Thermal stability of Form E has been investigated by TG-DTA and in situ by temperature resolved X-ray powder diffraction. Water loss occurs between 50 degrees C