Coated preparation soluble in the lower digestive tract

摘要

A coating dispersion soluble in the lower digestive tract which is prepared by blending a hydroxypropyl methylcellulose acetate succinate (HPMCAS) soluble at around pH 7 with a conventional plasticizer and an anion surfactant and further adding an acid, wherein the HPMCAS has an average particle size of 10 mum or less and is dispersed at a concentration of 2 to 20% by weight, and the acid is used in an amount of 1 to 10 parts by weight per 100 parts by weight of HPMCAS, and a sustained release coated preparation capable of releasing a medicament in the large intestine at the lower digestive tract, which is prepared by coating a medicament-containing solid preparation such as a granular core with the coating dispersion.