INFLUENCE OF PARTICLE SIZE ON THE DEGRADATION OF POLY(LACTIDE-CO-GLYCOLIDE)-BASED MICROSPHERES

C. BUSATTO; IGNACIO M. HELBLING; DR. JULIO A. LUNA; D.A. ESTENOZ

Santa Fe

Congreso; XI SIMPOSIO ARG. DE POLIMEROS - SAP 2015.-; 2015

Summary. Polymer degradation plays a crucial role in drug delivery from sustained release polyester systems, therefore is essential to characterize the degradation behaviour of these devices. The aim of this study was to investigate the effect of particle size on the in vitro degradation of poly(lactic-co-glycolic acid) (PLGA)-based microspheres. Microspheres were prepared by the oil-in-water emulsion solvent evaporation technique. Differential scanning calorimetry (DSC), scanning electron microscopy (SEM), nuclear magnetic resonance (NMR) and size exclusion chromatography (SEC) were used to study polymer degradation and morphological changes of the microparticles during degradation process. Higher degradation rates were achieved with larger particles. For smaller particles, degradation products formed within the microspheres can readily diffuse to the surface and dissolve into the surrounding medium. On the other hand, for larger particles, diffusion pathways increase and polymer degradation rate undergoes an autocatalytic effect during diffusion of degradation products.