Patent ID: 7871644

Claim:
A method of improving oral absorption in the digestive tract of an oral drug by orally administering a pharmaceutical composition obtained by bringing the drug which is difficult to absorb, which forms an insoluble complex, an aminoalkyl methacrylate copolymer E, an acidic substance together and uniformly mixing at least the polymer and said acidic substance, wherein said pharmaceutical composition is 1 or 2 or more selected from the group consisting of granules, tablets, capsules, and liquid; and wherein the C max and AUC of said drug is increased in the presence of said copolymer E and said acidic substance, and wherein the ratio of said polymer is 0.5˜250 parts by weight per 1 part by weight of the drug and the acidic substance is used in the amount that will neutralize 10% or more of the basic groups of aminoalkyl methacrylate copolymer E and wherein the digestive tract is the small intestine consisting of the duodenum, jejunum, and ileum, and the large intestine consisting of the colon, the ascending colon, transverse colon, descending colon, and sigmoid colon, and the rectum, wherein said pharmaceutical composition has improved absorption in the digestive tract.