Patent ID: 8344165
Filing Date: 2013-01-01
Classification: A61P,C07D

Abstract:
1. A method of preparing the crystalline rotigotine base having an X-ray powder diffraction pattern comprising peaks at 14.6, 15.2, 15.6, 16.6, 17.0, 19.7, 20.2, 22.6 and 27.8 degrees 2θ, the method comprising: (a) dissolving or partially dissolving rotigotine hydrochloride in a first organic solvent and water; (b) adding a base to the mixture of (a) to form rotigotine base; (c) removing the water and the first organic solvent of (b) to form a residue; (d) adding water and a second organic solvent to the residue; (e) removing the water and the second organic solvent from the mixture of step (d) to obtain crude rotigotine base; and (f) crystallizing the crude rotigotine base from a third organic solvent selected from n-pentane, n-hexane, cyclohexane, n-heptane, petroleum ether, and mixtures thereof, to form crystalline rotigotine base.