Preparation and In Vitro Degradation Behavior of Poly(L-lactide-co-glycolide) by Direct-Melt Polycondensation

Poly(L-lactide-co-glycolide)(PLGA)copolymer (85/15) was prepared by direct-melt polycondensation instead of a ring-opening process. The polymer samples were hydrolyzed at 37°C in phosphate-buffered saline (PBS) for periods up to 10 weeks and the degradation behavior was characterized through weight average molecular mass change, mass loss, water uptake, and morphology. The results indicate that mass loss, weight average molecular mass, and water uptake of PLGA increase with increasing time; however, pH value of the PBS solution decreases. The degradation is heterogeneous—degradation in their central parts was faster than in the surface and regions due to the increased concentration of the acidic degradation products inside.