Disclosed is a pharmaceutical composition of a lyophilized formulation including a multiblock copolymer in which two or more ABA-type triblocks are covalently connected through biodegradable dicarboxylic linkage, wherein A represents a polyethylene oxide block and B represents a polypropylene oxide block, a polybutylene oxide block, or a block of copolymer of propylene oxide and butylene oxide, the multiblock copolymer being included in an amount of 1 to 7 wt% based on the total weight of solution prior to the lyophilized formulation. The composition is capable of reducing reconstitution time of a lyophilized sustained-release formulation.
