Estimation of zorifertinib metabolic stability in human liver microsomes using LC–MS/MS

Abstract

Zorifertinib (AZD-3759; ZFB) is a novel, potent, oral, small molecule used to treat non-small cell lung cancer. ZFB is an epidermal growth factor receptor inhibitor that is capable of crossing blood–brain barrier. The in silico metabolic software used for ZFB metabolic stability prediction was the StarDrop software package (WhichP450 module). An LC-MS/MS analytical method (fast and accurate) was established for ZFB quantification in human liver microsomes (HLMs) in order to estimate its metabolic stability. ZFB and encorafenib (ENF) (internal standard; IS) were separated through the use of an isocratic mobile phase system with a C8 stationary phase column. The LC-MS/MS method for ZFB exhibited linearity in the range of 5 ng/mL to 500 ng/mL in HLMs matrix with a linear regression equation: y = 0.2438x - 0.341 (R² = 0.9992). The limit of quantification (LOQ) was 3.78 ng/mL confirming the LC-MS/MS method sensitivity. The inter- and intraday accuracy and precision were less than 9.56% confirming the reproducibility of the LC-MS/MS method. The intrinsic clearance and in vitro half-life of ZFB were 32.5 µL/min/mg and 21.33 min, respectively. ZFB exhibited a moderate extraction ratio that revealed good bioavailability. Literature review demonstrated that the developed analytical method is the first developed LC-MS/MS method for determining ZFB metabolic stability.