DETERMINATION OF CETIRIZINE IN SERUM USING REVERSED-PHASE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ULTRAVIOLET SPECTROPHOTOMETRIC DETECTION

A method using reversed-phase high-performance liquid chromatography with ultraviolet detection for the determination of ceterizine in serum is described. The method is sensitive down to 50 ng/ml (250-mul loop). Sample preparation involves only serum deproteination with perchloric acid and injection of the centrifuged supernatant. Elution is at pH 2.5 with acetonitrile-methanol-0.05 M phosphate buffer (33:9:58, v/v) on a 25 cm x 4.6 mm I.D. Spherisorb S5 ODS2 column. Detection is at 211 nm, its lambda(max). For levels above 300 ng/ml the serum sample size is 100 mul and a 200-mul sample is necessary for concentrations less than 300 ng/ml. At the 2 mug/ml concentration the intra-assay relative standard deviation is better than 2.2%, whilst the inter-assay deviation is 2.6% over eight samples. At 200 ng/ml the intra-assay relative standard deviation is 6% over seven samples. Detector response is linear from 100 ng/ml to 10 mug/ml (100-mul loop).