Kohei Yamamoto;Tsutomu Tani;Takashi Aoki;Yoshio Hata
发明人:
Kohei Yamamoto,Tsutomu Tani,Takashi Aoki,Yoshio Hata
申请号：
US11822128
公开号：
US08092830B2
申请日:
2007.07.02
申请国别(地区):
US
年份:
2012
代理人:
摘要：
A process for producing a lactic acid polymer of 15,000 to 50,000 in weight-average molecular weight, the content of polymeric materials having not more than about 5,000 in weight-average molecular weight therein being not more than about 5% by weight, characterized by hydrolyzing a high molecular weight lactic acid polymer, placing the resultant solution comprising the hydrolyzed product under a condition capable of precipitating the objective lactic acid polymer, separating the precipitated lactic acid polymer and collecting them. The lactic acid polymer is useful as a matrix for sustained-release preparations. The sustained-release microcapsule preparation encapsulating a physiologically active substance can fully prevent the initial excessive release of the physiologically active substance from the microcapsules and keep a stable release rate over a long period of time.
