Abstract: The present invention provides a sustained-release composition by which a sustained-release effect can be obtained for a long time when injecting microparticles of the composition in an amount that can be subcutaneously or intramuscularly injected to a human with ease and without pain. The composition comprises porous hydroxyapatite microparticles having pores embolized by filling the pores in the microparticles with a biologically active drug, a human serum protein, and a mucopolysaccharide, and adding a divalent metal ion. Alternatively, the composition comprises porous hydroxyapatite microparticles having pores embolized in the outer layer by filling the pores in the microparticles with a biologically active drug, a human serum protein, and a water-soluble calcium salt one after another or at one time, and then adding sodium carbonate, sodium hydrogen carbonate, or an aqueous carbonate ion solution.

Abstract: To provide: drug-encapsulating inorganic microparticles in which a method of producing pharmaceutical preparations is simple, which are not stimulative, which are applicable to a great number of potent proteins, potent low-molecular weight compounds and genes, and once applied thereto, enable the potent proteins, potent low-molecular weight compounds and genes to be kept stable, and which give an excellent sustained release effect and a targeting effect to the drugs; a method of manufacturing the same; and pharmaceutical preparations of drug-encapsulating inorganic microparticles.

Abstract: The invention relates to a composition providing sustained release of a drug, the composition including (1) a mucopolysaccharide, a carrier protein, and a drug; or (2) a mucopolysaccharide and a protein drug.