title: Analysis of omeprazole, midazolam and hydroxy-metabolites in plasma using liquid chromatography coupled to tandem mass spectrometry.
abstract: A method has been developed and validated for the quantitation of midazolam, alphahydroxy-midazolam, omeprazole, and hydroxyomeprazole from one 250 microL sample of human plasma using high performance liquid chromatography coupled to tandem mass spectrometry. The method was validated for a daily working range of 0.400-100 ng/mL, with limits of detection between 2 and 15 pg/mL. The inter-assay variation was less than 15% for all analytes at four control concentrations and the samples were stable for three freeze-thaw cycles under the analysis conditions and 24 h in the post-preparative analysis matrix. This method was used to analyze samples in support of clinical studies probing the activity of the cytochrome P-450 enzyme system.
authors: Pharmacotherapy Research Center, Core Analytical Laboratory, Department of Pharmacy Practice, University at Buffalo, The State University of New York, Room 311, Hochstetter Hall, Buffalo, NY 14260, USA. zuccari@buffalo.edu
authors: Valerie A
authors: VA
authors: Frerichs
authors: Colleen
authors: C
authors: Zaranek
authors: Curtis E
authors: CE
authors: Haas
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000284:Administration, Oral; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D065731:Cytochrome P-450 CYP2C19; D006801:Humans; D007275:Injections, Intravenous; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D008874:Midazolam / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics; D006899:Mixed Function Oxygenases / Q000378:metabolism; D009853:Omeprazole / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000097:blood* / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D013997:Time Factors
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; C049963:5-hydroxymethylomeprazole; C040081:1-hydroxymethylmidazolam; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C045793:CYP2C19 protein, human; D065731:Cytochrome P-450 CYP2C19; D009853:Omeprazole; D008874:Midazolam