Development of a voltammetric procedure for assay of the antihistamine drug hydroxyzine at a glassy carbon electrode: Quantification and pharmacokinetic studies

An electrochemical study of hydroxyzine at a glassy carbon electrode was carried out in the Britton-Robinson universal buffer of pH 2-11. Hydroxyzine was oxidized in a single two-electron irreversible process controlled mainly by adsorption. A simple, sensitive and time-saving square-wave adsorptive anodic stripping voltammetric procedure has been developed for determination of hydroxyzine in its commercial tablets and human serum without prior extraction. The optimized procedural conditions were: frequency = 120 Hz, scan increment = 10 mV, pulse-amplitude = 25 mv, accumulation potential = -0.3 V, accumulation time = 90-300 s and a Britton-Robinson universal buffer of pH 4 as a supporting electrolyte. Mean recoveries of 100.5 +/- 0.71 and 98.6 +/- 1.12% (n = 5) were achieved for assay of hydroxyzine in Atarax((R)) 10 and 25 mg dosage forms, respectively. Limit of detection of 1.5 x 10(-8) mol L-1 (5.624 ng mL(-1)) and limit of quantitation of 5.0 x 10(-8) mol L-1 (18.746 ng mL(-1)) were achieved in human serum with a mean recovery of 98.4 +/- 1.22%, without prior extraction of the drug. Moreover, the described procedure was applied for evaluating the pharmacokinetic parameters of hydroxyzine in plasma of two healthy volunteers after administration of a single oral dose (Atarax((R))-25 mg). (C) 2007 Elsevier B.V. All rights reserved.