FESOTERODINE COMPRISING A REDUCED AMOUNT OF DEHYDROXYFESOTERODINE

摘要

Provided herein is an impurity of fesoterodine, fesoterodine dehydroxy impurity, 2-[(lR)-3- [bis(l-methylethyl)amino]-l-phenylpropyl]-4-methylphenyl isobutyrate, and a process for preparing and isolating thereof. Provided further herein is a highly pure fesoterodine or a pharmaceutically acceptable salt thereof substantially free of fesoterodine dehydroxy impurity, process for the preparation thereof, and pharmaceutical compositions comprising highly pure fesoterodine or a pharmaceutically acceptable salt thereof substantially free of dehydroxy impurity. Provided also herein is a pharmaceutical composition comprising solid particles of pure fesoterodine fumarate substantially free of dehydroxy impurity, wherein 90 volume-percent of the particles (D90) have a size of less than about 200 microns.