METHOD FOR PREPARING HYDROXYPROPYL METHYLCELLULOSE ACETATE SUCCINATE (HPMCAS) GRAINS HAVING CONTROLLED GRAIN SIZE DISTRIBUTION, AND HPMCAS POWDER

摘要

Disclosed are a method for preparing hydroxypropyl methylcellulose acetate succinate (HPMCAS) grains and HPMCAS grains. The disclosed method for preparing HPMCAS grains comprises: a step of esterifying hydroxypropyl methylcellulose (HPMC), acetic anhydride, and succinic anhydride in a reaction medium in the presence of a catalyst so as to obtain a reaction solution containing HPMCAS (esterification step); and a step of continuously or intermittently putting the reaction solution into water so as to form grains (granulating step).