Simultaneous quantitative determination of seven novel tyrosine kinase inhibitors in plasma by a validated UPLC-MS/MS...

A rapid, sensitive and reproducible ultra-high performance liquid chromatography mass spectrometry method was developed and validated for simultaneous determination of seven tyrosine kinase inhibitors (dasatinib, foretinib, osimertinib, gefitinib, ibrutinib, linifanib and motesanib) in human plasma samples using quizartinib as internal standard (IS). The sample preparation was performed by liquid-liquid extraction method, using a mixture of ethyl acetate and tert butyl methyl ether (50:50, v/v) as extracting solvents. Chromatographic separation was achieved using acquity UPLC BEH C₁₈, 1.7 µm 2.1 × 100 mm column and a mobile phase consisting of a mixture of acetonitrile (0.1% formic acid) and 20 mM ammonium acetate (95:5) at a flow rate of 0.25 mL/min. All the analytes and IS were eluted within 2 min, with total run time of 3 min only. The electrospray ionization in positive mode was used and all analytes were monitored using multiple reaction monitoring (MRM) mode. The method was linear and reproducible for all the compounds in the range of 5-1000 ng/mL. Between- and within-run accuracy ranged from 86.7% to 92.5%, and the precision was less than 11.9% for all seven compounds. The developed method was successfully applied to in-vitro human microsomal metabolic stability study. This method could be useful in clinical application for therapeutic drug monitoring (TDM) of these analytes and for individualization of therapeutic regimens.