title: Development and validation of an automated SPE-LC-MS/MS assay for valdecoxib and its hydroxylated metabolite in human plasma.
abstract: A sensitive and specific liquid chromatography-tandem mass spectrometry assay was developed to quantitate valdecoxib (I) and its hydroxylated metabolite (II) in human plasma. The analytes (I and II) and a structurally analogue internal standard (IS) were extracted on a C(18) solid phase extraction (SPE) cartridge using a Zymark RapidTrace automation system. The chromatographic separation was performed on a narrow-bore reverse phase Zorbax XDB-C(8) HPLC column with a mobile phase of acetonitrile:water (50:50, v/v) containing 10 mM ammonium acetate. The analytes were ionized using negative electrospray mass spectrometry, then detected by multiple reaction monitoring (MRM) with a tandem mass spectrometer. The precursor to product ion transitions of m/z 313-->118 and m/z 329-->196 were used to measure I and II, respectively. The assay exhibited a linear dynamic range of 0.5-200 ng/ml of I and II in human plasma with absolute recoveries from plasma at 91 and 86%, respectively. The lower limit of quantitation was 0.5 ng/ml for I and II. Acceptable precision and accuracy were obtained for concentrations over the calibration curve ranges (0.5-200 ng/ml). Sample analysis time for each injection was 5 min, a throughput of 70 human plasma standards and samples per run was achieved. The assay has been successfully used to analyze human plasma samples to support clinical phase I and II studies.
authors.affiliation: Pharmacokinetics, Dynamics and Metabolism, Pfizer Inc., 4901 Searle Parkway, Skokie, IL 60077, USA. ji.y.zhang@pfizer.com
authors.forename: Ji Y
authors.initials: JY
authors.lastname: Zhang
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Fast
authors.forename: Alan P
authors.initials: AP
authors.lastname: Breau
mesh_terms: D001711:Biotransformation; D002138:Calibration; D002853:Chromatography, Liquid; D016861:Cyclooxygenase Inhibitors / Q000097:blood* / Q000493:pharmacokinetics; D005615:Freezing; D006461:Hemolysis; D006801:Humans; D006900:Hydroxylation; D007555:Isoxazoles / Q000097:blood* / Q000493:pharmacokinetics; D016014:Linear Models; D013058:Mass Spectrometry; D011786:Quality Control; D012015:Reference Standards; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D013449:Sulfonamides / Q000097:blood* / Q000493:pharmacokinetics; D000096926:Benzenesulfonamides
chemical_list: D016861:Cyclooxygenase Inhibitors; D007555:Isoxazoles; D013449:Sulfonamides; C406224:valdecoxib; D000096926:Benzenesulfonamides