In this study, the residual solvent in final purified paclitaxel was effectively removed using microwave-assisted drying.When the sample final purified by silica-HPLC was concentrated using a rotary evaporator, the residual methanol easily met the ICH-specified value (3000 ppm), but methylene chloride did not meet the ICH-specified value (600 ppm). Thus, the efficiency of microwave-assisted drying according to microwave power (100, 200, and 300 W) and drying time was investigated using the sample (methylene chloride conc.: 26,000 ppm, methanol conc.: 50 ppm) concentrated by rotary evaporation. A higher microwave power was effective in removing methylene chloride, and the ICH requirements were met by drying at 300 W for 21 h. In addition, when the sample concentrated by rotary evaporation was vacuum dried (35 degrees C, 24 h), the concentration of methylene chloride could be reduced to 8500 ppm. When the vacuum-dried sample was subjected to microwave-assisted drying, the ICH requirements could be met by drying for 10 h at 200 W and 8 h at 300 W. The lower the initial concentration of the solvent and the higher the microwave power, the greater the improvement in the efficiency of microwave-assisted drying. (C) 2013 Elsevier Ltd. All rights reserved.