Simultaneous Quantitation of Anlotinib and Osimertinib by Isotope-Labeled UHPLC-MS/MS in Human Plasma: Application in NSCLC Patients.

Anlotinib and osimertinib are a class of tyrosine kinase inhibitors for the treatment of malignant tumor. The combination of anlotinib and osimertinib is currently used for treating non-small cell lung cancer (NSCLC) patients. This study aimed to develop a simple and rapid isotope-labeled UHPLC-MS/MS method for the simultaneous determination of anlotinib and osimertinib in human plasma. The analytes were extracted by protein precipitation with acetonitrile and were then separated on a Shim-pack GIST C18 column. The detection was performed on Shimadzu 8050 triple quadruple mass spectrometer in the positive electrospray ionization mode with multiple reaction monitoring. The precursor-to-product ion transitions were m/z 408.10→ 339.75, 500.25→ 72.20 and 413.50 → 344.50 for anlotinib, osimertinib and D5-anlotinib, respectively. Validation is based on US Food and Drug Administration guidelines. The linearity ranges were 0.5-100 ng/mL for anlotinib and were 1-500 ng/mL for osimertinib with the correlation coefficients (r  2) ≥ 0.99. Accuracy and precision, matrix effect, extraction recovery and stability of anlotinib and osimertinib were acceptable after validation. The UHPLC-MS/MS method was successfully validated and was applied to monitor the concentration of anlotinib and osimertinib in NSCLC patients.