FIELD: chemistry.
SUBSTANCE: described BAB block copolymer includes: (a) about 60 to 85 wt % of a biodegradable, hydrophobic block A comprising a biodegradable polyester; and (b) about 15 to 40 wt % of a biodegradable, hydrophilic block B comprising polyethylene glycol, wherein the weight-average molecular weight of each block B is between 300 and 1000 Da; The BAB block copolymer has weight-average molecular weight Mw ranging from 5000 to 8000 Da and the ratio of block A to block B is 2.45, 2.50, 2.60 or 2.70. The block copolymer is capable of exhibiting reverse thermal gellation properties when formed in an aqueous solution. Also described is a composition of said block copolymer for administering a medicinal agent, as well as a method of producing same. Described is an aqueous composition of said block copolymer. Also described is a method of administering at least one medicinal agent to a warm blooded animal in a controlled release form, which comprises: (a) providing an aqueous composition of the BAB copolymer, comprising: (i) about 60 to 85 wt % of a biodegradable, hydrophobic block A comprising a biodegradable polyester; and (ii) about 15 to 40 wt % of a biodegradable, hydrophilic block B comprising polyethylene glycol, wherein the weight-average molecular weight of each block B is between 300 and 1000 Da; where the weight-average molecular weight Mw of the BAB block copolymer ranges from 5000 to 8000 Da and the ratio of block A to block B is 2.45, 2.50, 2.60 or 2.70, wherein the BAB block copolymer is exhibits reverse thermal gellation properties; and (b) administering said composition to a warm blooded animal.
EFFECT: obtaining low-molecular weight block copolymers, having reverse thermal gellation properties and improved drug release characteristics.
15 cl, 2 dwg, 2 tbl, 4 ex
