Determination of Diosgenin in Rat Plasma by UPLC-MS/MS / 中国药学杂志

ABSTRACT

OBJECTIVE: To develop and validate a sensitive and specific ultra-performance liquid chromatography-tandemmass spectrometric (LC-MS/MS) method for the assay of diosgenin in rat plasma. METHODS: Tanshinone ⅡA was employed as internal standard. Diosgenin was determined after the methanol-mediated plasma protein precipitation. The separation was performed on the Phenomenex kinetex xb C18 column (2.1 mm×50 mm, 2.6 μm) gradiently eluted with the mobile phase consisting of methanol(containing 0.1% formic acid)-0.1% aqueous formic acid. The flow rate was 0.2 mL·min-1, the column temperature was maintained at 40℃, and the injection volume was 5 μL. A triple quadrupole mass spectrometer equipped with electrospray ionization source was used as detector in a positive ion mode. Multiple reaction monitoring (MRM) mode was applied with the transition of m/z 415.2→271.1 and m/z 295.1→249.1 for diosgenin and internal standard, respectively. RESULTS: For diosgenin the standard curve was linear from 10 to 500 ng·mL-1(r=0.998 3), the limit of quantitative limit was 10 ng·mL-1, the intra- and inter-assay variabilities were below 15%, the accuracies were between 96.1% and 102.3%, the average extract recoveries ranged from 73.8% to 75.2%, and the matrix effects was between 85.8% and 91.7%. For the internal standard, the extract recovery and matrix effects were 83.8% and 92.4%, respectively. The rats were administered orally with diosgenin (100 mg·kg-1). The peak concentration of diosgenin was (344.067±34.48) ng·mL-1, the time for peak concentration was (4.167±2.041) h, the half-time was (14.85±10.53) h, and the area under concentration-time curve from zero to 72 h was (4 965.648±1 036.129) μg·h·L-1. CONCLUSION: This assay is specific, simple, sensitive and rapid, which can be applied in the pharmacokinetic study of diosgenin in rats.