AN IMPROVED PROCESS FOR THE PREPARATION OF AMORPHOUS [R(R*,R*)-2-(4-FLUORO PHENYL), P S, DIHYDROXY-5-(1-METHYL ETHYL)-3-PHENYL-4-[(PHENYL AMINO)CARBONYL)-1H-PYRROLE-1-HEPTANOIC ACID HEMI EALCIUM SALT (ATORVASTATIN CALCIUM SALT)
The objective of the invention is to provide an efficient and alternative process for the preparation of amorphous atorvastatin calcium salt, which eliminates the problems of prior art and is convenient to operate on a commercial scale, and also involves ecofriendly process over the prior art. The present invention provides the improved process for the preparation of amorphous atorvastatin calcium, which comprises dissolving crystalline or blend of crystalline or mixture thereof including amorphous atorvastatin calcium in ester solvents preferably ethyl acetate followed by removal of solvent by spray drying or Ultrafilm agitated thin film drying- vertical (ATFD-V), further drying under vaccum to get amorphous atorvastatin calcium. The process for the production of amorphous form of Atorvastatin involves one step conversion of [R-(R*, R*)]-2-(4-fluorophenyl)-P, 8-dihydroxy -5- (1-methylethyl) -3-phenyl-4-[(phenyl amino)-carbonyl]-lH-pyrrole-l-heptanoic acid, tertiary butyl ester, (hereinafter referred to as "ester" for convenience) to amorphous form of Atorvastatin calcium via crude Atorvastatin calcium .
