Localized paclitaxel delivery

While the search for new antineoplastic agents is in progress, optimization of delivery for existing drugs will remarkably improve the current scenario in the management of cancer. Paclitaxel, a new antineoplastic agent, is one such drug deserving attention in the field of regional drug delivery, offering immense pharmacokinetic as well as therapeutic advantage via localized delivery. The antiangiogenic activity of paclitaxel has been demonstrated using the chick chorioallantoic membrane model (CAM). This review focuses on the antiangiogenic activity of paclitaxel supported by the evidence that angiogenesis inhibitors display potential synergism with cytotoxic agents in the treatment of primary and metastatic cancers. Preclinical trials have confirmed that the biological and cytotoxic effects of paclitaxel on several tumor cell lines are enhanced by the increase in both the drug concentration and the duration of exposure. Sufficient experimental evidence has accumulated to state that localized delivery will exploit the multiple pharmacological effects of paclitaxel in the treatment of refractory and metastatic cancerous diseases. The drug delivery systems, namely, microspheres, surgical 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 devices in the battle against solid tumors. Finally, the review briefs on the possibilities for better paclitaxel delivery and the future drug delivery systems for localized cancer chemotherapy. (C) 1999 published by Elsevier Science B.V. All rights reserved.