Dexamethasone-releasing PLGA films containing sucrose particles as porogens

Abstract

The objective of this study was to investigate the use of sucrose particles as a porogen for preparing porous poly (lactide-co-glycolide) (PLGA) films containing dexamethasone by solvent casting technique to modulate PLGA degradation and drug release. Increasing the sucrose content up to 30 % decreased PLGA degradation and extended the drug release duration, a further increase to more than 60 % shortened the release duration. Sucrose created cavities and increased the internal pore surface area for the exchange of degraded acidic oligomers and monomers. This process decreased the autocatalysis within the PLGA matrix, resulting in slower drug release at lower sucrose content. At higher sucrose content, the interconnectivity of the PLGA matrix increased, accelerating the drug release of the entrapped drug. Decreasing the particle size of sucrose has a similar impact on PLGA degradation and drug release as increasing sucrose content. Smaller sucrose particles formed more cavities and a larger overall acidic exchange surface areas. Only 20 % nanosized sucrose resulted in a quasi-linear release profile with interconnected sucrose particles, while 60 % micronized or 100 % non-micronized sucrose particles were necessary to achieve the same effect. In conclusion, modifying the content and particle size of sucrose effectively altered PLGA degradation and drug release, with nanosized sucrose being the most effective porogen. The data obtained with PLGA films could be potentially applied to other PLGA drug delivery systems such as microparticles or implants.