%0 Journal Article
%T Validation of a rapid liquid chromatography tandem mass spectrometric method for the quantitative analysis of vistusertib.
%A Scott SC
%A Anders NM
%A Scardina M
%A Hann CL
%A Rudek MA
%J J Pharm Biomed Anal
%V 208
%N 0
%D Jan 2022 20
%M 34735991
%F 3.571
%R 10.1016/j.jpba.2021.114436
%X Vistusertib is an orally bioavailable mTOR inhibitor that is being studied in clinical trials. A novel reliable method was developed to quantitate vistusertib using LC-MS/MS to explore drug exposure-response relationships. Sample preparation involved protein precipitation using acetonitrile. Separation of vistusertib and the internal standard, AZD8055, was achieved with a Waters Acquity UPLC BEH C18 column utilizing isocratic elution over a 3 min total analytical run time. A SCIEX 4500 triple quadrupole mass spectrometer operated in positive electrospray ionization mode was used for the detection of vistusertib. The assay range was 5-5000 ng/mL and proved to be accurate (98.7-105.7%) and precise (CV ≤ 10.5%). A 40,000 ng/mL sample that was diluted 1:10 (v/v) with plasma was accurately quantitated. Long-term frozen plasma stability for vistusertib at -70 °C has been determined for at least 29 months. The method was applied for the measurement of plasma concentrations of vistusertib in a patient a solid tumor receiving 35 mg twice daily dose orally.