ORAL PHARMACEUTICAL PREPARATION FOR COLON-SPECIFIC DELIVERY
An oral pharmaceutical preparation excellent in the ability to deliver a drug to the large intestine, more specifically, an oral pharmaceutical prepa ration for delivering a drug to the large intestine which comprises a core c ontaining a pharmaceutically acceptable filler as the essential component, a drug-containing inside layer covering the core, an intermediate layer which covers the inside layer and contains a cationic polymer soluble or swellabl e at a pH of 6.6 or below, and an outside layer which covers the intermediat e layer and contains an anionic polymer soluble at a pH of 7.0 or above.