Development of a validated and sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to simultaneous determination of crizotinib, alectinib and lorlatinib in human plasma.

Crizotinib, alectinib, and lorlatinib are tyrosine kinase inhibitors used sequentially in non-small cell lung cancer (NSCLC) therapy. Therapeutic drug monitoring (TDM) is valuable during sequential treatment, enabling simultaneous quantification. Consequently, an analytical method capable of multiplexing these three compounds into a single assay is highly applicable for routine TDM. A multiplexed UHPLC-MS/MS method quantifying all three drugs was validated for selectivity, matrix effects, linearity (20-1000 ng/mL), accuracy, precision, carryover, and stability. Matrix effects were negligible in both plasma from healthy volunteers and plasma from patients with hyperlipidemia. No significant interfering responses were observed for crizotinib, alectinib, lorlatinib, or their corresponding isotope-labeled internal standards. Sample stability was confirmed under ambient conditions (25 °C) for at least 24 h. Furthermore, the pretreated supernatant remained stable in the auto sampler (15 °C) for 24 h. This validated method is suitable for application in pharmacokinetic studies and exposure-response assessments.