PREPARATION OF ENTERIC COATED PHARMACEUTICAL

PURPOSE:To obtain the titled pharmaceutical having improved storage stability related to the enteric properties (solubility in the intestines), by forming an undercoating layer containing a higher fatty acid on a solid drug before forming an enteric coating film layer. CONSTITUTION:An undercoating layer is formed on the surface containing a higher fatty acid, e.g. stearic acid or palmitic acid, is formed on the surface of a solid drug, e.g. a tablet, granule or capsule, and an enteric coating layer consisting of hydroxypropyl methyl cellulose phthalate or cellulose acetate phthalate, etc. is then formed on the undercoating layer. Hydroxypropyl (methyl) cellulose, etc. is used as a film base material for the undercoating layer, and the amount thereof is preferably 0.2-5wt% based on the solid drug for the tablet, and 1-10wt% based on the solid drug for the granule. The pharmaceutical exhibits remarkable effects on soft gelatin capsules and tablets and granules containing an alkaline substance.