Controlled Release of Antibiotics from Biodegradable Microcapsules for Wound Infection Control

摘要

It is the goal of this study to develop microcapsules that slowly release effective therapeutic doses of antibiotics in a wound over a 14-day period, by which time microcapsules will have been biodegraded. It is the purpose of this paper to report the in vivo results obtained using recently formulated prototype microcapsules. All initial efforts in the development of the controlled antibiotic release system have used ampicillin with lactide/glycolide copolymer as the drug vehicle. This copolymer is ideally suited for in vivo drug release since it elicits a minimal inflammatory response, is biologically compatible, and degrades under physiologic conditions. The degradation products are nontoxic and readily metabolized. All microcapsules currently formulated exist as free-flowing microspheres (<250 microns in diameter) consisting of ampicillin anhydrate coated with a poly (DL-lactide-co-glycolide) excipient having a lactide:glycolide ratio of 68:32. Microcapsules of this size can be adminstered directly to a wound by a shaker-type dispenser or aerosol spray. The rate of biodegradation is controllable because it is related to the molar ratios of the constituent polymers and to the surface area of the microcapsules.