Development and Validation of an Ecofriendly, Rapid, Simple and Sensitive UPLC-MS/MS Method for Entrectinib Quantification in Plasma for Therapeutic Drug Monitoring

Entrectinib is an oral selective inhibitor of the neurotrophic T receptor kinase (NTRK). It is used in the treatment of solid tumors in NTRK gene fusion lung cancer. The study aimed to develop and validate an analytical method for quantifying entrectinib plasma by UPLC-MS/MS using quizartinib as an internal standard. The method involves liquid-liquid extraction of entrectinib from plasma using tert butyl methyl ether. The mass-to-charge transitions were 561.23 & RARR; 435.1 for entrectinib and 561.19 & RARR; 114.1 for quizartinib. The method was successfully validated according to ICH and FDA guidelines. The method has a low quantification limit of 0.5 ng/mL, and the calibration curves constructed over a wide range of 0.5-1000 ng/mL showed good linearity (& GE;0.997). This method exhibits a tenfold increase in sensitivity compared with the previous method. The method is also accurate, precise, and reproducible, as evidenced by the inter-day and intra-day accuracy and precision values of 82.24-93.33% and 3.64-14.78%, respectively. Principles of green analytical chemistry were considered during all analytical steps to ensure safety. The greenness of the methods was evaluated using two assessment tools. These tools are the Analytical Eco-Scale and the analytical greenness metric approach (AGREE). The results were satisfactory and compatible with the criteria of these tools for green assessment. This method is green, accurate, precise, and reproducible. The method can be used to quantitate entrectinib in plasma and its pharmacokinetics in preclinical, and therapeutic drug monitoring.