PHARMACEUTICAL DOSAGE FORM WITH MULTIPLE COATINGS

The present invention relates to a pharmaceutical composition in a solid unit dosage form for oral administration in a human or lower animal comprising: a. a safe and effective amount of a therapeutically active agent; b. an inner coating layer selected from the group consisting of poly(methacrylic acid, methyl methacrylate) 1:2, poly(methacrylic acid, methyl methacrylate) 1:1, and mixtures thereof; and c. an outer coating layer comprising an enteric polymer or film coating material; wherein the inner coating layer is not the same as the outer coating layer; wherein if the inner coating layer is poly(methacrylic acid, methyl methacrylate) 1:1 then the outer coating layer is not poly(methacrylic acid, methyl methacrylate) 1:2 or is not a mixture of poly(methacrylic acid, methyl methacrylate) 1:1 and poly(methacrylic acid, methyl methacrylate) 1:2; and wherein the inner coating layer and the outer coating layer do not contain any therapeutically active agent. This invention further relates to a method of maintaining the desired site of delivery of a therapeutic agent in the gastrointestinal tract by administering the above compositions to a human or lower animal.