Mohammad Sadegh Amini-Fazl - Iran Polymer and Petrochemical Institute, P.O. Box: 14965-115, Tehran, Iran.
Hamid Mobedi - Iran Polymer and Petrochemical Institute, P.O. Box: 14965-115, Tehran, Iran.
Jalal Barzin - Iran Polymer and Petrochemical Institute, P.O. Box: 14965-115, Tehran, Iran.

During past decade, injectable in situ-forming gels have attracted considerable attentions as polymeric drug carriers due to their ability to conform to any shape at specific site andthe fact that they can be introduced using minimally invasive non-surgical procedures [1]. Delivery systems provide theopportunity to localize high concentration of drug within the desired part of body, while reducing adverse effects. Poly(lactic acid-co-glycolic acid), PLGA, as a biodegradableand biocompatible polyester has been employed as candidate injectable in situ-forming gel [2].Paclitaxel is the most important anticancer agent developed inthe last two decades. Since the late of 1970s, it has been used for the treatment of advanced breast, ovarian, lung, head andneck [3]. The major mechanism of its activity is by preventing the cells from dividing by promoting the assembly ofmicrotubules without inhibiting their disassembly [3]. During last two decades, several delivery systems were developed for loading of Paclitaxel, such as liposomes [4], microspheres [5],and in situ forming gels [1, 2]. The purpose of this study was to develop Cremophor® EL free in situ-forming implants loaded with Paclitaxel toimprove the therapeutic index of the drug and devoid of the adverse effects of Cremophor® EL. The in vitro release of Paclitaxel from the gels was studied through high performance liquid chromatography (HPLC) analysis.