title: Simple and selective method for the determination of various tyrosine kinase inhibitors used in the clinical setting by liquid chromatography tandem mass spectrometry.
abstract: A fast, sensitive, universal and accurate method for the determination of four different tyrosine kinase inhibitors from biological material was developed using LC-MS/MS techniques. Utilizing a simple protein precipitation with acetonitrile a 20 microl sample volume of biological matrixes can be extracted at 4 degrees C with minimal effort. After centrifugation the sample extract is introduced directly onto the LC-MS/MS system without further clean-up and assayed across a linear range of 1-4000 ng/ml. Chromatography was performed using a Dionex Ultimate 3000 with a Phenomenex prodigy ODS3 (2.0 mm x 100 mm, 3 microm) column and eluted at 200 microl/min with a tertiary mobile phase consisting of 20mM ammonium acetate:acetonitrile:methanol (2.5:6.7:8.3%). Injection volume varied from 0.1 microl to 1 microl depending on the concentration of the drug observed. Samples were observed to be stable for a maximum of 48 h after extraction when kept at 4 degrees C. Detection was performed using a turbo-spray ionization source and mass spectrometric positive multi-reaction-monitoring-mode (+MRM) for Gefitinib (447.1 m/z; 127.9 m/z), Erlotinib (393.9 m/z; 278.2 m/z), Sunitinib (399.1 m/z; 283.1 m/z) and Sorafenib (465.0 m/z; 251.9 m/z) at an ion voltage of +3500 V. The accuracy, precision and limit-of-quantification (LOQ) from cell culture medium were as follows: Gefitinib: 100.2+/-3.8%, 11.2 nM; Erlotinib: 101.6+/-3.7%, 12.7 nM; Sunitinib: 100.8+/-4.3%, 12.6 nM; Sorafenib: 93.9+/-3.0%, 10.8 nM, respectively. This was reproducible for plasma, whole blood, and serum. The method was observed to be linear between the LOQ and 4000 ng/ml for each analyte. Effectiveness of the method is illustrated with the analysis of samples from a cellular accumulation investigation and from determination of steady state concentrations in clinically treated patients.
authors.affiliation: Department of Medical Oncology, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: R
authors.initials: R
authors.lastname: Honeywell
authors.forename: K
authors.initials: K
authors.lastname: Yarzadah
authors.forename: E
authors.initials: E
authors.lastname: Giovannetti
authors.forename: N
authors.initials: N
authors.lastname: Losekoot
authors.forename: E F
authors.initials: EF
authors.lastname: Smit
authors.forename: M
authors.initials: M
authors.lastname: Walraven
authors.forename: J S W
authors.initials: JS
authors.lastname: Lind
authors.forename: C
authors.initials: C
authors.lastname: Tibaldi
authors.forename: H M
authors.initials: HM
authors.lastname: Verheul
authors.forename: G J
authors.initials: GJ
authors.lastname: Peters
mesh_terms: D000097:Acetonitriles / Q000737:chemistry; D002853:Chromatography, Liquid / Q000379:methods*; D004355:Drug Stability; D006801:Humans; D016014:Linear Models; D009369:Neoplasms / Q000097:blood / Q000188:drug therapy; D047428:Protein Kinase Inhibitors / Q000032:analysis* / Q000097:blood / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000097:Acetonitriles; D047428:Protein Kinase Inhibitors; C032159:acetonitrile