The present invention relates to composition of microparticles comprisinga suspension of substantially amorphous protein microparticles, the compositionproviding a concentration of at least about 50 mg of said protein per ml of saidcomposition, and the protein has a molecular weight of at least about 25,000 Daltons.In accordance with the method of production, the active agent is dissolved inan aqueous or aqueous-miscible solvent containing a dissolved phase-separationenhancing agent (PSEA) to form a solution in a single liquid phase. The solutionis subjected to a liquid-solid phase separation to cause the active agent to formsmall spherical that are substantially amorphous or non-crystalline and areinjectable through fine gauge needles at high concentrations. The inventionhas special application for higher molecular weight proteins.
