Establishment and validation of a LC-MS/MS method for the determination of anlotinib in human plasma: Application to therapeutic drug monitoring

Anlotinib is a novel small molecule multitarget tyrosine kinase inhibitor for the treatment of several cancers. We developed and validated a highly sensitive, rapid and stable high-performance liquid chromatography-mass spectrometrymethod for the determination of anlotinib in human plasma with anlotinib-d(5) as a stable isotopically labeled internal standard (SIL-IS). To explore the feasibility of therapeutic drug monitoring in the treatment of tumors with anlotinib, human plasma samples were prepared by protein precipitation. The mobile phases comprised of (A) 5.0 mm NH(4)AC aqueous solution containing 0.1% formic acid and (B) 100% methanol containing 0.1% formic acid. A gradient mobile phase system was adopted for chromatographic separation using a BEH C18 (2.1 x 50 mm, 1.7 mu m) column. A positive ion pattern was chosen for quantification under multiple reaction monitoring mode. The ion pairs were detected at m/z 408.2 -> 339.1 and m/z 413.4 -> 344.3 for anlotinib and anlotinib-d(5) (SIL-IS), respectively. The total run time was 5.0 min. The calibration curve was found to be linear within a plasma concentration range of 2-400 ng center dot ml(-1). The precision and accuracy, matrix effect, extraction recovery and stability were all validated and met the requirements of international guidelines. The proposed methods were successfully applied to support therapeutic drug monitoring in breast and thyroid cancer patients receiving anlotinib for therapy. Clinical data showed that in the 12 mg dose group, the mean plasma concentrations of anlotinib in breast cancer patients and thyroid cancer patients were 87.1 and 118.8 ng center dot ml(-1), respectively. The data demonstrate that the peak concentration of anlotinib may be related to the different tumor types in patients.

Automated summary

This study developed and validated a highly sensitive, rapid, and stable method for quantifying the concentration of Anlotinib in human plasma. Therapeutic drug monitoring can be used to determine the peak concentration of Anlotinib in the plasma of patients with different types of tumors.