Patent ID: 7511174
Filing Date: 2009-03-31
Classification: A61P,C07F

Abstract:
1. A process for preparing solid ibandronic acid comprising the steps of: a) combining a halo-phosphorous compound and phosphorous acid with N-methyl-N-pentyl propionic acid or a hydrochloride salt of N-methyl-N-pentyl propionic acid in a diluent selected from the group consisting of silicone oil, toluene and a mixture of toluene and phosphoric acid to form a mixture; b) heating the mixture to a temperature of about 80° C. to about 100° C.; c) combining the mixture with water to form a biphasic mixture having aqueous and organic phases; d) separating the aqueous and organic phases; e) heating the aqueous phase at a temperature of about 95° C. to about 110° C.; f) evaporating the aqueous phase to obtain a residue of ibandronic acid; g) combining the residue with a C h) recovering the precipitated solid ibandronic acid from the mixture.