Enantioselective analysis of albendazole sulfoxide in plasma using the chiral stationary phase.

We present a method for the enantioselective analysis of albendazole sulfoxide (ABZSO) in plasma for application in clinical pharmacokinetic studies. ABZSO enantiomers were separated on a 5-micron Chiralcel OB-H column (4.6 x 150 mm) using hexane:ethanol (93:7, v/v) as the mobile phase and fluorescence detection. ABZSO was extracted with chloroform:isopropanol (8:2, v/v) from 500-microliter aliquots of acidified plasma, with full drug recovery. The proposed method presented quantitation limits of 20 ng/ml for (-)ABZSO and 50 ng/ml for (+)ABZSO and was linear up to a concentration of 5,000 ng/ml of each enantiomer.