Determination of fibrauretin concentrations in rat plasma by LC-MS/MS and its pharmacokinetics

Objective To establish a LC-MS/MS method to determine fibrauretin concentrations in rat blood and study the pharmacokinetics of fibrauretin in rat by the method. Methods Separation was performed by an Agilent Zorbax Eclipse XDB-C18 column (2.1 mm × 50 mm, 1.8 μm) and the mobile phase consisted of acetonitrile and 0.1% formic acid aqueous solution (30 : 70). The quantification analysis of fibrauretin was performed using multiple reaction monitoring (MRM) pattern. The plasma was analyzed after a simple protein precipitation procedure with acetonitrile. The blood sample was collected from retinal vein, and the concentration of fibrauretin in rat blood was analyzed by the established method, and the pharmacokinetics parameters were calculated by the DAS2.0 software. Results The linear range of fibrauretin in rat plasma was 0.442 ~ 44.2 ng/ml. The precision, extraction recovery and stability limit of this method met the requirements of pharmacokinetic study. The pharmacokinetics of fibrauretin in rats was fitted with two-compartment model. After oral administration of fibrauretin of 40 mg/kg, the pharmacokinetic parameters including the half time (t1/2) and the peak time and were 6 h and 2.8 h respectively, and the maximum plasma concentration was 19.8 ng/ml. Conclusions Established in this study in vivo determination method of high sensitivity and specificity, can be used for pharmacokinetic studies of fibrauretin in rats, which provides a strong support for its applied research.