Localized paclitaxel delivery

While the search for new antineoplastic agents is in progress, optimization of delivery for existing drugs will remarkably improve the current scenari o in the management of cancer. Paclitaxel, a new antineoplastic agent, is o ne such drug deserving attention in the field of regional drug delivery, of fering immense pharmacokinetic as well as therapeutic advantage via localiz ed delivery. The antiangiogenic activity of paclitaxel has been demonstrate d using the chick chorioallantoic membrane model (CAM). This review focuses on the antiangiogenic activity of paclitaxel supported by the evidence tha t angiogenesis inhibitors display potential synergism with cytotoxic agents in the treatment of primary and metastatic cancers. Preclinical trials hav e confirmed that the biological and cytotoxic effects of paclitaxel on seve ral tumor cell lines are enhanced by the increase in both the drug concentr ation and the duration of exposure. Sufficient experimental evidence has ac cumulated to state that localized delivery will exploit the multiple pharma cological effects of paclitaxel in the treatment of refractory and metastat ic cancerous diseases. The drug delivery systems, namely, microspheres, sur gical pastes and implants, fabricated for localized paclitaxel delivery are reviewed explaining the concept of increased tumor burden alleviating body burden as a consequence of such delivery systems. Some of the preclinical trials are very encouraging and speculate a promising future for these devi ces in the battle against solid tumors. Finally, the review briefs on the p ossibilities for better paclitaxel delivery and the future drug delivery sy stems for localized cancer chemotherapy. (C) 1999 published by Elsevier Sci ence B.V. All rights reserved.