An enteric coating agent is used to protect drugs from degradation by gastric acid or to protect gastric mucosa from
irritating drugs. HPMCP (hypromellose phthalate), since its introduction into the market in 1971 as an alternative cellulose derivative for enteric coating,has been demonstrated to bean effective and safe material by the pharmaceutical industry. HPMCP has been admitted into the U.S. National Formulary (USP/NF), European Pharmacopoeia (EP), and Japanese Pharmacopoeia (JP).