In vitro degradation of polylactide and poly(lactide-co-glycolide) microspheres

✍ Scribed by Jia-Huei Zhu; Zheng-Rong Shen; Lan-Ting Wu; Shi-Lin Yang

• Publisher: John Wiley and Sons
• Year: 1991
• Tongue: English
• Weight: 833 KB
• Volume: 43
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1991.070431117

✦ Synopsis

People's Republic of China SYNOPSIS Polylactide (PLA) and poly (lactide-co-glycolide) (PLGA) were prepared by bulk ringopening polymerization of lactide or lactide/glycolide using stannous octoate as initiator. PLA and PLGA microspheres with an average diameter of 65-100 pm were prepared by a solvent evaporation process. An in uitro degradation test of different molecular weight PLA and of different composition PLGA were carried out in p H 7.4 buffer solution at 37°C in the form of microspheres. Quantitatively, the degree of degradation was monitored by gel permeation chromatography ( GPC) , by measurement of mass loss and determination of lactic/glycolic acid in degradation medium, and qualitatively, by observing the morphological changes of microspheres with a scanning electron microscope (SEM) . The decrease in weight average molecular weight (A?,,,) for PLA with higher molecular weight is faster at the first degradation stage; afterward, the tendency of M, to decrease for PLA with different molecular weight is almost the same. PLGA degrades much faster than does PLA, and the degradation rate is significantly enhanced with the increase of glycolic acid (GA) content in copolymers.