Preparations with controlled release

Abstract

A controlled release preparation containing at least one kind of a pharmaceutically active ingredient, a male piece and a female piece, the pieces fitting together to enclose the active substance therein, wherein the male piece is made from a material that gels in the intestinal juice, is disclosed. In a preferable mode, the male piece contains an ethyl acrylate-methyl methacrylate-trimethylammonioethyl methacrylate chloride copolymer and a methacrylic acid-ethyl acrylate copolymer. In a preferable mode, the female piece is made from a water insoluble polymer. In a preferable mode, the dosage form is a tablet or a capsule. The controlled release preparation of the present invention does not at all release a drug in the region having a low pH, such as in the stomach, but only in the region having a pH relatively near the neutral range, such as in the small bowel and the large bowel, the plug gradually gels from the upper surface and, after a given time when a part of the male piece (plug) having the least thickness gels and has become permeable, concurrently releases the drug in a short time in a pulse manner. Consequently, the drug can act effectively at a local site in the lower part of the small bowel, the large bowel and the like, and a drug can be delivered to the lower part of the small bowel or the large bowel without undergoing decomposition of peptides and proteins.