COPOLIMEROS TRIBLOQUE DE POLI (LACTIDO-CO-GLYCOLIDE) POLYETHYLENGLYCOL OF LOW MOLECULAR WEIGHT BIODEGRADABLE WITH INVERSE THERMAL GELIFICATION PROPERTIES.

摘要

An aqueous biodegradable polymeric drug distribution composition having thermal reverse gelation properties consisting of an aqueous phase having uniformity contained therein: a) an effective amount of a drug; and b) an ABA or BAB type triblock polymer, said ABA triblock having the formula: PL (G) z-1A - PEG-PL (G) z-1A and said BAB triblock having the formula PEG-PL (G) z- 1A - PEG in which z is an integer of 1 or 2, in which block A is represented by PL (G) z-1A so that when z is 2 block A is a poly (lactide-co-copolymer) - glycolide) or PLGA, and when z is 1 the block a is a poly (lactide) or PLA polymer and in which the block B is represented by PEG which is a hydrophilic polyethylene glycol polymer, said block copolymer having a molecular weight weight average of between about 2000 to 4990 and block A PL (G) z-1A comprises about 51 to 83% by weight of said block polymer and block B of PEG comprises about between 17 and 49% by weight of said block copolymer, and wherein the concentration of said block copolymer is between 3% and 50% by weight and said composition exists as a solution between 5 ° C and 25 ° C but it forms a gel when the temperature rises to body temperatures of a warm-blooded animal.