Simultaneous Estimation of Vinpocetine and Its Metabolite, Apovincaminic Acid, in Beagle Plasma by LC-MS-MS

A method was developed to determine vinpocetine and its metabolite, apovincaminic acid, in beagle plasma by LC-MS-MS. After protein precipitation with methanol, the supernatant of the sample was concentrated and injected into an Agilent Zorbax XDB-C₁₈ column. The sample was separated by a mobile phase consisting of acetonitrile and 0.2% formic acid solution, and the reading was determined on an Agilent 6410 Triple Quad Tandem mass spectrometer in multiple reaction monitoring mode with the following transitions: m/z 351.5 → 280.2/266.3 for vinpocetine, 323.2 → 236.1/280.2 for apovincaminic acid, and 411.2 → 191.1 for the internal standard. The intra- and inter-day variances were less than 15% (RSD%), and average recoveries were higher than 80%. The linearity ranges (LR) between 0.1 and 20.0 ng mL⁻¹ for vinpocetine (r ² = 0.9980) and between 1.0 and 200.0 ng mL⁻¹ for apovincaminic acid (r ² = 0.9995) were established. In summary, this method is sensitive, specific, and appropriate for in vivo study of various dosage forms of vinpocetine.