HIGHLY PURE PALIPERIDONE OR A PHARMACEUTICALLY ACCEPTABLE SALT THEREOF SUBSTANTIALLY FREE OF KETO IMPURITY

摘要

Provided herein is a highly pure paliperidone or a pharmaceutically acceptable salt thereof substantially free of keto impurity, 3-[2-[4-(6-fluoro-1,2-benzisoxazol-3-y1)-1- piperidinyl]ethyl]-2-methyl-7,8-dihydro-6H-pyrido[1,2-a]pyrimidin-4,9-dione, a process for the preparation thereof, and pharmaceutical compositions comprising highly pure paliperidone or a pharmaceutically acceptable salt thereof substantially free of keto impurity.