摘要:
Delivery system for bioactive agents on the basis of a polymeric drug carrier formed from compositions comprising an amphiphilic block copolymer of a hydrophilic block and a hydrophobic block having a terminal hydroxyl group substituted with a tocopherol or cholesterol group, and a polylactic acide derivative wherein one end of the polylactic acid is covalently bound to at least one carboxyl group. The carboxyl group of the polylactic acid derivative may be fixed with a di- or trivalent metal ion,which is obtained by adding the di- or trivalent metal ion to the polymeric composition.