PRODUCTION OF PHARMACEUTICALLY OR VETERINARICALLY ADMITTABLE, AMPHIPATHIC, UNCROSSLINKED, LINEAR, BRANCHED OR GRAFT BLOCK COPOLYMER

摘要

PURPOSE: To provide a method for producing a pharmaceutically or veterinarily acceptable and amphipathic copolymer having self dispersibility in water. CONSTITUTION: This method for producing a pharmaceutically or veterinarily acceptable amphipathic non-cross-linked linear, branched or graft block copolymer comprises freeze-drying a frozen, stable aqueous dispersion of the pharmaceutically or veterinarily acceptable non-cross-linked linear, branched or graft copolymer, having a minimum weight-average molecular weight of 1,000, containing the hydrophobic component which is biodegradable or hydrolytically unstable under normal physiological conditions and the hydrophilic component which may or may not be biodegradably or hydrolytically unstable under the same conditions. The block copolymer is useful for producing a pharmaceutical preparation of the drug for sustained continuous release injection.