Enteric coated stable oral pharmaceutical composition of acid unstable drug and process for preparing the same

摘要

Enteric coated stable oral pharmaceutical composition of acid unstable drug. The enteric coating is a bilayer with a pH gradient across its thickness comprising an inner layer of neutral or near neutral pH 7-7.5 and an outer layer of acidic pH 2-6. Also process for preparng the enteric coated stable oral pharmaceutical composition of acid unstable drug. The enteric coating is first carried out at neutral or near neutral pH of 7-7.5 to form an inner layer of neutral or near neutral pH and then at acidic pH of 2-6 to form an outer layer of acidic pH.