A controlled-release formulation comprising a flowable delivery system, a water-soluble organic solvent and a bioactive agent. The delivery system comprises a biocompatible, biodegradable, non-hydrolyzed linear poly(lactide-glycolide) (PLG) low-burst copolymer material having a weight average molecular weight of 10 to 50 kDa and a polydispersity index of 1.4 to 2Ø The PLG low-burst copolymer material does not include a linear copolymer fraction that is characterized by a weight average molecular weight of 4 to 10 kDa and a polydispersity index of 1.4 to 2.5. A method for the preparation of the PLG low-burst copolymer material is provided. Uses of the formulation are provided.
