Mohamed D.Hegazy M.A.Elshahed M.S.Toubar S.S.Helmy M.I.Analytical Chemistry DepartmentFaculty of PharmacyHelwan UniversityCairoEgypt; Pharmaceutical Analytical Chemistry DepartmentFaculty of PharmacyOctober University for Modern Sciences and Arts6 October CityEgypt; Analytical Chemistry DepartmentFaculty of PharmacyCairo UniversityCairoEgypt2020-01-092020-01-0920182693879https://doi.org/10.1002/bmc.4232PubMed ID 29505100https://t.ly/2dPbOScopusA facile, fast and specific method based on liquid chromatography�tandem mass spectrometry (LC�MS/MS) for the simultaneous quantitation of paracetamol, chlorzoxazone and aceclofenac in human plasma was developed and validated. Sample preparation was achieved by liquid�liquid extraction. The analysis was performed on a reversed-phase C18 HPLC column (5 ?m, 4.6 � 50 mm) using acetonitrile�10 mM ammonium formate pH 3.0 (65:35, v/v) as the mobile phase where atrovastatin was used as an internal standard. A very small injection volume (3 ?L) was applied and the run time was 2.0 min. The detection was carried out by electrospray positive and negative ionization mass spectrometry in the multiple-reaction monitoring mode. The developed method was capable of determining the analytes over the concentration ranges of 0.03�30.0, 0.015�15.00 and 0.15�15.00 ?g/mL for paracetamol, chlorzoxazone and aceclofenac, respectively. Intraday and interday precisions (as coefficient of variation) were found to be ?12.3% with an accuracy (as relative error) of �5.0%. The method was successfully applied to a pharmacokinetic study of the three analytes after being orally administered to six healthy volunteers. Copyright � 2018 John Wiley & Sons, Ltd.EnglishOctober University for Modern Sciences and Artsجامعة أكتوبر للعلوم الحديثة والآدابUniversity of Modern Sciences and ArtsMSA UniversityaceclofenacchlorzoxazoneHPLC�MS/MShuman plasmaparacetamolpharmacokinetic studyaceclofenacacetonitrileammonium formateatorvastatinchlorzoxazoneparacetamolaceclofenacchlorzoxazonediclofenacparacetamolArticlecontrolled studydrug blood levelhumanhuman experimentliquid chromatography-mass spectrometryliquid liquid extractionnormal humansingle drug doseanalogs and derivativesbloodchemistrylimit of detectionliquid chromatographymaleproceduresreproducibilitystatistical modeltandem mass spectrometryAcetaminophenChlorzoxazoneChromatography, LiquidDiclofenacHumansLimit of DetectionLinear ModelsMaleReproducibility of ResultsTandem Mass SpectrometryArticlehttps://doi.org/10.1002/bmc.4232PubMed ID 29505100