SUSTAINED-RELEASE COMPOSITION, AND PRODUCTION METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a sustained-release composition which contains a physiologically active substance, particularly leuprorelin in a high content even if it does not contain gelatin, and suppresses excessive initial release thereof to be able to achieve a stable releasing rate over about one month.SOLUTION: A production method of a sustained-release composition comprises: mixing an aqueous solution only containing a physiologically active substance which is leuprorelin or a salt thereof, to an organic solvent solution only containing a lactic acid-glycolic acid polymer having a ratio of a weight average molecular weight to a number average molecular weight of 1.90 or less, or a salt thereof; dispersing; and then removing an organic solvent.