Development and validation of a novel LC-MS/MS method for simultaneous quantitative determination of tyrosine kinase inhibitors in human plasma

The objective of this study was to develop and validate a simple, rapid, and sensitive liquid chromatography -tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of three tyrosine kinase inhibitors (ceritinib, osimertinib, and crizotinib) in human plasma using a single-step protein precipitation extraction. Chromatographic separation was achieved using a Waters X Bridge C18 (2.1 mm x 100 mm, 3.5 mu m) and gradient elution with 0.2 % formic acid in water and acetonitrile. The total run time was 4.0 min, and the injection volume was 5 mu L. The analytes were detected in the multiple reaction monitoring mode using elec-trospray ionization with positive ion mode. The m/z transitions of ceritinib, osimertinib, crizotinib and nilotinib were 558.0 -> 433.2, 500.0 -> 72.1, 450.0 -> 259.3, and 530.0 -> 289.1, respectively. The method was linear in the range of 2-500 ng/mL with lower limit of quantification of 2 ng/mL. Based on the guidelines on bioanalytical methods by the FDA, the validation studies demonstrated that the three analytes were both precise and accurate at four concentration levels, and the coefficient of variation was < 10.59 % and accuracy was > 88.26 %. We present a simple, rapid, and sensitive method for the simultaneous quantification of ceritinib, osimertinib, and crizotinib in human plasma by LC-MS/MS, which could be used in routine therapeutic drug monitoring.