摘要 |
PURPOSE:To obtain an enteric coating film having excellent strength of coating film and acid resistance by blending a hydroxypropylmethyl cellulose phthalate(HPMCP) having specific viscosity with specific amounts of polyethylene glycol(PEG) and shellac. CONSTITUTION:An enteric coating film comprising (A) HPMCP having 18.0-22.0% methoxyl group content, 5.0-9.0% hydroxypropoxyl group content, 27.0-35.0% carboxybenzoyl group content, about 240 average polymerization degree and 136-204 centistokes viscosity in 10% solution at 20 deg.C, (B) 0.1-20wt.%, preferably 2-10wt.% based on the component A of a PEG having 1,200-25,000 average molecular weight solid at normal temperature and (C) 5-40wt.%, preferably 15-35wt.% based on the component A of shellac. A solution of the component A in acetone is mixed with an ethanol solution having dissolved the PEG and shellac to prepare a coating solution, which is sprayed upon preparation to give an enteric preparation. |