TEMPERATURE AND PH SENSITIVE BLOCK COPOLYMERS EXCELLENT IN GEL STRENGTH AND ITS MANUFACTURING PROCESS, AND DRUG CARRIER USING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide a block copolymer sensitive to temperature and pH, and to provide its manufacturing process and a drug carrier using the same. SOLUTION: A multi-block copolymer comprises (a) a polyethylene-based compound (A) or a copolymer (B) of (A) with a biodegradable polyester-based polymer; and (b) the polyethylene-based compound (A) or the copolymer (B) coupled with a polyurethane oligomer (C). The multi-block copolymer being a hydrogel has both hydrophilic property, which is temperature-sensitive, and hydrophobic property as well as pH-sensitivity characteristic in which ionization property varies with pH of ambient surroundings. The multi-block copolymer can form a polymeric hydrogel structure that can be used as a target directional drug carrier which functions in accordance with the change in pH in the living body. COPYRIGHT: (C)2009,JPO&INPIT