Paclitaxel release from single and double-layered poly(DL-lactide-co-glycolide)/poly(L-lactide) film for biodegradable coronary stent application.

Abstract

Our laboratory has been developing a completely biodegradable coronary stent which is made of bilayers of biodegradable polyesters. This article presents the preliminary work done to exploit the drug delivery potential of such a polymeric stent. An antiproliferative drug (paclitaxel) was added either only to the top layer or to both layers and the in vitro release profiles were monitored for up to 90 days. Within 90 days, the measured paclitaxel release was almost entirely from the P(DL)LGA layer. In general, the release profiles show three distinct stages: (a) extremely slow diffusional release, (b) accelerated diffusion-degradation release, and (c) saturation. Separate degradation studies (water absorption, molecular weight reduction, weight loss, and surface topography) were also conducted to better understand the observed release behavior.