BLOCK COPOLYMER REDUCED IN IMPURITY CONTENT, POLYMERIC CARRIER, PHARMACEUTICAL PREPARATIONS IN POLYMERIC FORM AND PROCESS FOR THE PREPARATION OF THE SAME
Block copolymer or salt thereof comprises polyethylene glycol and polyacidic amino acid and 10 wt% impurity. Independent claims are also included for: (1) preparation of a copolymer or salt thereof, by refining polyethylene glycol derivative with ion exchange resin, removing protective group if necessary, and treating with absorbing resin； (2) a polymer carrier wherein the polyacidic amino acid is condensed with anthra cycling type caner controlling residual groups； (3) preparation of the carrier； and (4) a polymer medicine comprising a block copolymer-medicine composite wherein anthra cycling cancer controlling agent is wrapped in the core of a polymer micelle.
