In vitro evaluation of polymeric matrix and porous biodegradable reservoir devices for slow-release drug delivery

. BACKGROUND AND OBJECTIVE: Biodegradable polymeric devices were evaluated in vitro for intravitreal drug delivery. . MATERIALS AND METHODS: The matrix (short-term drug delivery) and the porous (longer-term drug delivery) reservoir devices were made from polycaprolactone of two molecular weights (30,000 and 56,000). Matrix devices were loaded with 5-fluorouracil or ganciclovir. Porous reservoirs were loaded with 5-fluorouracil, ganciclovir, 5-carboxyfluorescein, or foscarnet. The release was monitored in phosphate-buffered solution using ultraviolet spectrophotometry. . RESULTS: Release from the matrix devices was characterized by an initial burst, followed by a nonlinear release. The porous reservoirs demonstrated zero-order linear release of drugs, sustained up to 250 days in this experiment. . CONCLUSIONS: The matrix device is capable of sustained release over several months; the porous reservoir can deliver drugs for over 1 year. Further studies are needed to evaluate in vivo biodegradation behavior and toxicity of drugs used for sustained release.