POLYMORPHS OF O-DESMETHYL VENLAFAXINE SUCCINATE

摘要

T h e present invention relates to crystalline forms of O-desmethyl venlafaxine ( O D V ) succinate monohydrate, namely Forms I and II, in pure form and to novel processes for their preparation. The present invention provides a process for the preparation of Form II free of Form I and a process for the preparation of Form I free of Form II. The present invention provides direct methods f o r the preparation of ODV succinate Form II from ODV free base a n d for the preparation of ODV succinate Form I from ODV free base.