Provided is a pharmaceutical composition, including a drug and a collagen, in which the composition is satisfactory in handleability and has sustained-release property. The sustained-release pharmaceutical composition includes: a drug; a collagen; and at least one kind of sugar selected from monosaccharides, disaccharides, trisaccharides, and tetrasaccharides. The inventors of the present invention have found that the in vivo administration of a collagen solution containing a sugar results in the gelation of a collagen. Based on this finding, the inventors have found that a composition containing a drug, a collagen, and a sugar can control the release rate of the drug, and such composition can be used as a sustained-release pharmaceutical composition.