Process for the production of amorphous atorvastatin calcium

Abstract

A process for the preparation of amorphous atorvastatin calcium and hydrates thereof which comprises: (a) dissolving crystalline atorvastatin calcium in a non-hydroxylic solvent; (b) adding a non-polar hydrocarbon anti-solvent or adding the dissolved atorvastatin to the non-polar anti-solvent to precipitate out atorvastatin calcium; and (c) removing the solvent by filtration to afford amorphous atorvastatin calcium.

We claim:  
     
         1 . A process for the preparation of amorphous atorvastatin calcium and hydrates thereof which comprises: 
 (a) dissolving crystalline atorvastatin calcium in a non-hydroxylic solvent;    (b) adding a non-polar hydrocarbon anti-solvent or adding the dissolved atorvastatin to the non-polar anti-solvent to precipitate out atorvastatin calcium; and    (c) removing the solvent by filtration to afford amorphous atorvastatin calcium.    
     
     
         2 . The process of  claim 1 , wherein the non-hydroxylic solvent is tetrahydrofuran and anti-solvent is chosen from a group of non-polar hydrocarbon solvents comprising n-hexane, cyclohexane or n-heptane.  
     
     
         3 . The process of  claim 1 , wherein the non-hydroxylic solvent is tetrahydrofuran and anti-solvent is n-hexane.  
     
     
         4 . The process of  claim 1 , wherein the non-hydroxylic solvent is tetrahydrofuran and anti-solvent is cylcohexane.  
     
     
         5 . The process of  claim 1 , wherein the non-hydroxylic solvent is tetrahydrofuran and anti-solvent is n-heptane.  
     
     
         6 . The process of  claim 1 , wherein said amorphous atorvastatin calcium is isolated by filtration.