Plasma and brain samples were extracted by protein precipitation using acetonitrile containing an appropriate internal standard. Specific reaction monitoring transitions were identified using automated instrumental optimization procedures for each compound studied, to ensure adequate linearity of response and define the upper and lower limits of quantitation. Samples were injected (SIL-30AC Autosampler, Schimadzu, Kyoto, Japan) onto a reverse phase chromatography system (A: 0.1% formic acid in ultrapure water; B: 0.1% formic acid in acetonitrile, Waters Corporation Acquity® UPLC column HSS T3 1.8μ). Analysis was performed using an API 5000 triple quadrupole mass spectrometer fitted with an electrospray ionisation source (AB Sciex, Ontario, ON, Canada). Pharmacokinetic analysis was performed with IDBS E-WorkBook v10 using mean data, non-compartmental analysis and the nominal dose of test item administered to the study animals.