DETERMINATION OF CETIRIZINE IN HUMAN URINE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A high-performance liquid chromatographic method for the determination of the histamine H-1-receptor antagonist cetirizine in human urine was developed. Cetirizine and the internal standard are extracted from acidified (pH 5) urine (0.5 ml) into chloroform and the organic layer is evaporated to dryness. The residue is chromatographed on a Spherisorb 5ODS-2 column using Pic A (5 mM aqueous tetrabutylammonium phosphate)-methanol-tetrahydrofuran (33:65:2, v/v) as the mobile phase with ultraviolet detection (230 nm). The calibration graph is linear from 0.1 to 10-mu-g/ml and using 0.5 ml of urine the detection limit is 20 ng/ml. The within-run relative standard deviation is < 6% and the accuracy is within 10% of the theoretical value at concentrations between 0.1 and 10-mu-g/ml in urine. There is a good correlation (r = 0.99606) with a previously described capillary gas chromatographic assay.