RECENT ADVANCES ON THE USE OF BIODEGRADABLE MICROPARTICLES AND NANOPARTICLES IN CONTROLLED DRUG-DELIVERY

The possibility of using biodegradable polymers as drug carriers was brought to the attention of many scientists when bioresorbable sutures entered the market two decades ago. Since that time, researchers in pharmacy, chemical engineering, and other disciplines have striven to design biodegradable polymers with desired degradation mechanisms and mechanical properties. Biodegradable polymers have advantages over other carrier systems in that they need not be surgically removed when drug delivery is completed and that they can provide direct drug delivery to the systemic circulation. The drug and polymer may be combined in a number of different ways depending upon the application of interest. Microparticulate formulations have the widest applicability to the widest variety of formulation needs: oral delivery, intramuscular injection, subcutaneous injection, and targeted delivery. This review addresses recent work utilizing biodegradable polymers for controlled drug delivery, focusing on micro- and nanoparticulate delivery systems containing poly(lactic acid), poly(glycolic acid) or their copolymers.