title: Liquid chromatography-tandem mass spectrometric assay for the mutated BRAF inhibitor dabrafenib in mouse plasma.
abstract: A quantitative bioanalytical liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay for the mutated BRAF inhibitor dabrafenib was developed and validated. Plasma samples were pre-treated using protein precipitation with acetonitrile containing PLX4720 as internal standard. The extract was directly injected into the reversed-phase chromatographic system after dilution with water. The eluate was transferred into the electrospray interface with positive ionization and the analyte was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. The assay was validated in a 2-2000 ng/ml calibration range with r(2)=0.993±0.002 for linear regression with quadratic weighting (n=5). Within day precisions (n=6) were 3.3-5.2%, between day (3 days; n=18) precisions 4.7-8.2%. Accuracies were between 95-104% for the whole calibration range. The drug was sufficiently stable under all relevant analytical conditions. Finally, the assay was successfully used to determine drug pharmacokinetics in mice.
authors.affiliation: Utrecht University, Faculty of Science, Department of Pharmaceutical Sciences, Division of Pharmacoepidemiology & Clinical Pharmacology, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands. R.W.Sparidans@uu.nl
authors.forename: Rolf W
authors.initials: RW
authors.lastname: Sparidans
authors.forename: Selvi
authors.initials: S
authors.lastname: Durmus
authors.forename: Alfred H
authors.initials: AH
authors.lastname: Schinkel
authors.forename: Jan H M
authors.initials: JH
authors.lastname: Schellens
authors.forename: Jos H
authors.initials: JH
authors.lastname: Beijnen
mesh_terms: D000818:Animals; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D007093:Imidazoles / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D016014:Linear Models; D051379:Mice; D010091:Oximes / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D048493:Proto-Oncogene Proteins B-raf / Q000037:antagonists & inhibitors*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D007093:Imidazoles; D010091:Oximes; D048493:Proto-Oncogene Proteins B-raf; C561627:dabrafenib