Pioglitazone salts, such as pioglitazone sulfate, and pharmaceutical compositions and processes using the same

Abstract

Water-soluble salts of pioglitazone especially pioglitazone sulfate are useful in pharmaceutical applications.

1 . A process, which comprises reacting pioglitazone or a salt thereof, other than a pioglitazone sulfate, with sulfuric acid in a solvent to form pioglitazone sulfate.  
   
   
       2 . The process according to  claim 1 , wherein said solvent comprises methanol.  
   
   
       3 . The process according to  claim 1 , which further comprises precipitating said pioglitazone sulfate.  
   
   
       4 . The process according to  claim 3 , wherein said precipitating comprises contacting said solvent containing pioglitazone sulfate with a contrasolvent.  
   
   
       5 . The process according to  claim 4 , wherein said contrasolvent is an ether, an aliphatic hydrocarbon, or a combination thereof.  
   
   
       6 . A process, which comprises contacting a pioglitazone salt with sufficient water for a sufficient time to precipitate solid pioglitazone base therefrom.  
   
   
       7 . The process according to  claim 6 , wherein said water does not contain a neutralizing agent.  
   
   
       8 . The process according to  claim 6 , wherein said pioglitazone salt is dissolved in a solvent when subjected to said contacting step.