title: Quantifying vemurafenib in dried blood spots using high-performance LC-MS/MS.
abstract: BACKGROUND
  To further investigate the pharmacokinetics of vemurafenib and to support therapeutic drug monitoring an LC-MS/MS method was developed and validated for the quantification of vemurafenib in dried blood spots.
  
  
  RESULTS
  Vemurafenib was extracted from the dried blood spots by methanol:acetonitrile (50:50, v/v) and separated on a C18 column with gradient elution and analyzed with triple quadrupole mass spectrometry in positive ion mode. The validated calibration range is linear from 1 to 100 µg/ml. Intra- and inter-assay accuracies and precisions were within ±13.6% and ≤6.5%. The applicability of the assay was tested by analyzing dried blood spots samples of melanoma patients receiving vemurafenib.
  
  
  CONCLUSIONS
  This assay met all predefined validation criteria and is considered suitable to quantify vemurafenib in dried blood samples.
authors.affiliation: Department of Pharmacy & Pharmacology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Nijenhuis
authors.forename: Hilde
authors.initials: H
authors.lastname: Rosing
authors.forename: Jan H M
authors.initials: JH
authors.lastname: Schellens
authors.forename: Jos H
authors.initials: JH
authors.lastname: Beijnen
mesh_terms: D053000:Analytic Sample Preparation Methods; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D059788:Dried Blood Spot Testing / Q000379:methods*; D006400:Hematocrit; D006801:Humans; D007211:Indoles / Q000097:blood*; D057230:Limit of Detection; D008545:Melanoma / Q000097:blood; D013449:Sulfonamides / Q000097:blood*; D053719:Tandem Mass Spectrometry; D000077484:Vemurafenib
chemical_list: D007211:Indoles; D013449:Sulfonamides; D000077484:Vemurafenib