Copolimero of dibloco and triblock, system of distribution of drugs of liberacao slow, process to prepare a copolimero block, and,Process for preparing a system of distribution of drugs to slow liberacao

摘要

The invention is an ABA or AB block copolymer as a well as slow release drug delivery system comprising a drug and the ABA or AB block copolymer wherein one block (B) is a poly (alkylene oxide) and the other blocks (A) are comprised of degradable random copolymers of (1) the cyclic ester of an alpha-hydroxy acid and (2) a second cyclic ester monomer with the proviso that the second cyclic ester monomer is not the same as the first cyclic ester.