|| Checking for direct PDF access through Ovid
A GC–MS method was developed and validated for the simultaneous determination of hydroxyzine and its active metabolite, cetirizine, in whole blood.The developed method provided significant advantages regarding sensitivity and linear dynamic range of related, previously published, methods.The method can be used during the investigation of clinical and forensic toxicology cases.The developed method was successfully applied during the investigation of clinical cases where these antihistamines were detected.The method could also be applied to pharmacokinetic studies concerning these antihistamines and the determination of more antihistamines in blood after proper optimization and validation.A simple, rapid, sensitive and accurate gas chromatography–mass spectrometric method was developed and validated for the simultaneous determination of hydroxyzine and cetirizine in whole blood. Solid-phase extraction procedure using Bond Elut LRC Certify II columns was used for the isolation of hydroxyzine and cetirizine from 1 mL whole blood followed by derivatization with a mixture of acetic anhydride:n-propanol (1:1, v/v). Limits of detection and quantification were 1.50 and 5.00 ng/mL, respectively. The assay was linear within the concentration range of 5.00–1000.0 ng/mL and the correlation coefficient was R2 ≥ 0.993 for both analytes. Absolute recovery was determined at three quality control concentration levels and was found to be at least 87.2% for both substances. Intra-day and inter-day accuracy values for both hydroxyzine and cetirizine were ranged from −1.2 to 3.8% and −2.7 to 2.0%, respectively, at the three concentration levels studied, whereas their respective intra-day and inter-day precision values were less than 9.9 and 6.5%, respectively, in terms of relative standard deviation (%RSD). The developed method was successfully applied for the quantification of hydroxyzine and cetirizine concentrations in whole blood, during the investigation of clinical cases where these two antihistamines were detected.