Synthesis and in vitro hydrolytic degradation of polyglycolide and its l-lactide copolymer

In this study homo- and copolymers of glycolide and l-lactide were synthesized and subjected to in vitro hydrolytic degradation. Glycolide and l-lactide were prepared from glycolic and l-lactic acid, respectively. Stannous octoate was used as polymerization catalyst. Poly(l-lactide) with M-w=9.4x10(5) and a polydispersity of 1.89 was synthesized and characterized. Also copolymers of l-lactide and glycolide were prepared. Polyglycolide and its lactide copolymers with high proportion of glycolide do not dissolve in organic solvents. Degradation studies were conducted at 37 degreesC and pH=7.35. The concentration of released glycolic acid was determined by chromotropic acid reagent. Purified polyglycolide powder shows a fast degradation profile in the first 10 days, after which it levels off. A copolymer obtained from 10 mol% l-lactide and 90 mol% glycolide shows different degradation pattern as polyglycolide, because of its amorphous nature it exhibits a higher degradation rate.