The removal of Cremophor® EL from paclitaxel for quantitative analysis by HPLC-UV

A novel method for analysis of hydrophobic drug Molecules ill matrices that contain Cremophor((R)) EL (CrEL) is presented. The method utilized a precipitation technique involving mercuric chloride in a reaction with CrEL to form all insoluble complex in an ethanol matrix. The hydrophobic drug molecule was then analyzed by HPLC-UV without interference from CrEL. Nuclear magnetic resonance and infrared spectroscopy indicated that the mechanism of precipitation involves the reaction of mercuric chloride with the ether bond of CrEL. Analysis by HPLC with UV detection of paclitaxel and related substances was used to verify that the reaction is specific toward CrEL. (c) 2005 Elsevier B.V. All rights reserved.