PROBLEM TO BE SOLVED: To provide a sustained-release composition which contains a physiologically active substance in high content even when gelatin is not included, and suppresses its initial excessive release and, thus, can achieve a stable release rate over about one month.SOLUTION: This sustained-release composition contains a lactic acid-glycolic acid polymer having a ratio of weight-average molecular weight and number-average molecular weight of about 1.90 or lower, a compositional molar ratio of the lactic acid to the glycolic acid of from 100:0 to 40:60, and weight-average molecular weight of from 3,000 to about 100,000, or a salt thereof, and a physiologically active substance.COPYRIGHT: (C)2012,JPO&INPIT【課題】ゼラチンを含有しなくても生理活性物質を高含量で含有し、かつその初期過剰放出を抑制して約1ヶ月にわたる安定な放出速度を実現できる徐放性組成物の提供。【解決手段】重量平均分子量と数平均分子量の比が1.90以下であり、乳酸とグリコール酸の組成モル比が100/0~40/60で重量平均分子量が3,000~100,000である乳酸-グリコール酸重合体またはその塩と、生理活性物質とを含有する徐放性組成物。【選択図】なし
