Patent ID: 7368581

Claim:
A process for preparing a crystalline form of fluvastatin sodium characterized by a PXRD pattern with peaks at 3.8, 11.1, 12.9, 17.8 and 21.7±0.2 degrees two-theta comprising: a) combining a C 1 to C 4 alkyl ester of fluvastatin with acetonitrile at a ratio of about 1:4-6 (Kg/L) of the ester to acetonitrile, and with water at a ratio of about 1:1.3-1:2 (Kg/L) of the ester to the water, to obtain a mixture; b) combining sodium hydroxide with the mixture to hydrolyze the ester, thereby obtaining a solution, wherein if aqueous sodium hydroxide is used, the water ratio does not exceed that provided in step (a); c) combining additional acetonitrile with the solution to precipitate crystalline fluvastatin sodium; and d) recovering crystalline fluvastatin sodium.