(93ad) Preparation and Analysis of a Plga Drug Delivery System for Polyphenols

The purpose of this research was to design a drug delivery system using a biodegradable polymer, poly(DL-lactide-co-glycolide)(PLGA), which is a copolymer of poly(lactic acid)(PLA) and poly(glycolic acid) (PGA). An advantage of biodegradable polymers over other drug carrier systems is that they are absorbed by the body, leaving no trace. PLGA drug delivery systems have been widely studied due to their biocompatibility, biodegradability, mechanical strength, and FDA approval. By combining PLA and PGA in different ratio and using different molecular weights, the delivery system can be tailored to release a drug with different release rates.

Specifically, biodegradable polymer films were prepared by casting acetone-based solutions containing different ratios of PLA to PGA (50/50, 65/35, or 75/25) and different inherent viscosity (e.g. 0.15 to 1.2 dL/g). PLGA and acetone were mixed in various weight percentages to get different film thickness. For drug release studies, extracted polyphenol was added to the PLGA acetone solution. After casting and drying in a vacuum oven, PLGA films were then allowed to degrade in phosphate buffered saline solution with a pH 7.4 at 37 degrees C. The degradation of the system was monitored by using weight loss analysis, and drug release was analyzed by measuring the concentration of the supernatant using UV-Vis absorption (polyphenol absorption peak at 207 nm). The rate of PLGA film degradation and drug release was demonstrated to depend upon the inherent viscosity and the thickness of the film. PLGA films with lower inherent viscosity degraded faster which was shown to result in higher drug release rates.

We would like to acknowledge Dr. Helieh S. Oz, director of animal studies in digestive diseases at the University of Kentucky, for providing assistance on this project.