An automated method for the measurement of a range of tyrosine kinase inhibitors in human plasma or serum using turbulent flow liquid chromatography-tandem mass spectrometry.

Tyrosine kinase inhibitors (TKIs) are used to treat a number of cancers, including chronic myeloid leukaemia and hepatocellular carcinoma. Therapeutic drug monitoring (TDM) may be indicated to (1) monitor adherence, (2) guide dosage, and (3) minimise the risk of drug-drug interactions and dose-related toxicity. On-line, automated sample preparation provided by TurboFlow technology (ThermoFisher Scientific) in conjunction with the sensitivity and selectivity of tandem mass spectrometry (MS/MS) detection may be applied to the analysis of single drugs and metabolites. We report the use of TurboFlow LC-MS/MS for the analysis of nine TKIs and metabolites (imatinib, N-desmethylimatinib, dasatinib, nilotinib, erlotinib, gefitinib, lapatinib, sorafenib, sunitinib) in human plasma or serum for TDM purposes. An Aria Transcend TLX-II system coupled with a TSQ Vantage was used. Samples (50 μL) were vortex mixed with internal standard solution (150 μL imatinib-D(8), gefitinib-D(8), sunitinib-D(10), and nilotinib-(13)C (2) (15) N(2) in acetonitrile) and, after centrifugation 100 μL supernatant were injected directly onto a 50 × 0.5-mm Cyclone TurboFlow column. Analytes were focussed onto a 50 × 2.1-mm (3 μm) Hypersil GOLD analytical column and eluted with an acetonitrile/water gradient. Analytes were monitored in selected reaction monitoring mode (positive APCI). Total analysis time was 7 min without multiplexing. Calibration was linear (R(2) > 0.99) for all analytes. Inter- and intra-assay precision (in percent relative standard deviation, RSD) was <11 % and accuracy 89-117 % for all analytes. No matrix effects were observed. This method is suitable for high-throughput TDM in patients undergoing chronic therapy with TKIs and has been utilised in the analysis of clinical samples.