Processes for preparation of crystalline mycophenolate sodium

Abstract

Provided are crystalline mycophenolate sodium forms and processes for their preparation.

1 . A process for preparing anhydrous crystalline mycophenolate sodium (Form M2) characterized by a powder XRD pattern with peaks at 5.3, 8.0, 9.8, 10.7, and 21.9±0.2 degrees 2-theta comprising the steps of: 
 (a) preparing a solution of mycophenolic acid in a C 3 -C 8  ketone;    (b) combining a base and a source of sodium with the solution to precipitate the crystalline form; and    (c) recovering the crystalline form.    
     
     
         2 . The process of  claim 1 , wherein the C 3 -C 7  ketone is acetone.  
     
     
         3 . The process of  claim 1 , wherein sodium methoxide, sodium ethoxide, or sodium hydroxide is used in step (b).  
     
     
         4 . The process of  claim 3 , wherein sodium hydroxide is used in step (b).