A novel LC-MS/MS method for determination of tissue distribution and excretion of timosaponin B-II in rat biological matrices.

Timosaponin B-II (TB-II) is a natural bioactive steroid glycoside extracted from the Chinese medicinal herb Anemarrhena asphodeloides Bge. (Fam. Liliaceae). It has been demonstrated to have a good anti-inflammatory effect and a low bioavailability (1.1%). Clinical research has focused on developing it into a completely new medicine. In this study, a rapid and sensitive analytical method based on LC-MS/MS has been developed for the determination of TB-II in rat biological matrices (tissues, bile, urine and feces samples). The analytes and internal standard were isolated from 100 μL samples by solid-phase extraction and then separated using a DIKMA Inertsil ODS-3 column (5 µm, 2.1 × 150 mm) with an isocratic mobile phase consisting of acetonitrile-0.05% formic acid (35:65) at a flow rate of 0.25 mL/min. Calibration curves (1/χ(2) -weighted) offered satisfactory linearity (r(2) ≥ 0.990) within the test range. The accuracy, precision, recoveries and matrix effects were satisfactory in all the biological matrices examined. The assay was successfully applied to a tissue distribution and excretion study in rats. The preclinical data are useful for the design of clinical trials of TB-II.