A sustained-release composition comprising a water soluble physiologically active peptide

Abstract

Sustained-release composition wherein a water-soluble physiologically active peptide represented by formula 5- oxo-Pro-His-Trp-Ser-Tyr-Y-Leu-Arg-Pro-Z wherein, Y represents DLeu, DAla, DTrp, DSer (tBu) , D2Nal or DHis (ImBzl) and Z represents NH-C2H5 or Gly-NH2, or a salt thereof is substantially uniformly dispersed in a microcapsule comprised of a lactic acid polymer thereof, and the physiologically active substance is contained in an amount of 15 to 35 wt / wt% to the total microcapsules and weight-average molecular weight (Mw) of the lactic acid polymer is about 11, 000 to about 27 ,000 I which is characterized by having a high content of the physiologically active substance, and suppression of the intial excessive release within one day after the administration and a stable drug sustained-release over a long period of time, and method for producing the same.