Abstract: A parenteral pharmaceutical preparation comprises a matrix containing a physiologically active peptide or protein and a polyglycerol diester of a saturated fatty acid, and the matrix is in a solid form at room temperature. The molecular weight of the physiologically active peptide or protein is 2,000 dalton or more. The saturated fatty acid includes fatty acids having about 16 to 30 carbon atoms such as palmitic acid, stearic acid, etc. The matrix may be in a pillar or granular form. The parenteral pharmaceutical preparation can be used as an injectable solid administered subcutaneously or intramuscularly (for example, a pellet or tablet for implantation), a suppository or the like, and can release the physiologically active peptide or protein sustainedly for a prolonged period of one week or more.

Abstract: A method of producing a sustained-release preparation which includes permitting a water-soluble polypeptide to permeate into a biodegradable matrix in the aqueous solution. The production method of the present invention makes possible the permeation of a water-soluble polypeptide into a biodegradable matrix without bringing the water-soluble polypeptide into contact with an organic solvent. Hence the water-soluble polypeptide is prepared without affecting the water-soluble polypeptide bioactivity and is thus effective for use as a pharmaceutical.