Optical purification of esomeprazole

摘要

The present invention relates to process for optical purification of esomeprazole or a salt thereof. Thus, esomeprazole sodium having 20 to 1% R-omeprazole by weight of the sum of the contents of esomeprazole and R-omeprazole is precipitated from a solvent selected from an alcohol or a mixture of alcohols and the precipitated solid is collected to obtain optically pure esomeprazole sodium.