Evaluation of surface area of mesoporous silica adsorbents for separation and purification of paclitaxel

Several types of mesoporous silica adsorbents with different surface areas at specific pore sizes (2 nm, 4-5 nm, and 29 nm) were prepared by spray pyrolysis and were used for the separation/purification of the anticancer agent paclitaxel. After adsorbent treatment and hexane precipitation, the purity of paclitaxel was found to be increased with increasing surface area of adsorbent. The highest paclitaxel yields were achieved using an absorbent with a surface area of 953 m(2)/g at a pore size of 2 nm, with a surface area of 575 m(2)/g at a pore size of 4-5 nm, and with a surface area of 131 m(2)/g at a pore size of 29 nm. It was clear that the surface area of the adsorbent affected not only the purity but also the yield of paclitaxel. Also, increasing the surface area of the adsorbent resulted in an increase in the adsorption of paclitaxel and impurities (biomass-derived tar and wax components). Removal of these impurities was confirmed by HPLC analysis of the absorbent after treatment and TGA of the organic substances that were adhered to the adsorbent. (C) 2013 Elsevier Inc. All rights reserved.