The present invention relates to a novel series of polymers which have been prepared by blending hydrophobic biocompatible, biodegradable polymers or copolymers, such as poly(lactide-co-glycolide), and a biocompatible, amphipathic copolymer having a water absorption ratio of about 2 or less. A process for the preparation of the novel polymer blends and sustained release compositions comprising the novel polymer blends are also part of the invention described herein. Further the sustained release compositions can be used to deliver a biologically active with a desirable release profile and in a sustained fashion to a patient in need thereof.