the presently claimed invention comprises a biopolymer nanoparticle for drug delivery wherein the nanoparticle comprises a homogeneous blend of an aliphatic polyester polymer blended with a polyether , a lipophilic or polypeptide drug and a biocompatible cholesterol interacting agent for preserving the activity of the drug administered to the patient while at the same time controlling the release of the drug . methods for making the homogeneous drug delivery nanoparticles are also disclosed .