Simultaneous analysis of polygala acid, senegenin and 3,6'-disinapoylsucrose in rat plasma by liquid chromatography-tandem mass spectrometry: application to a pharmacokinetic study after oral administration.

A rapid and specific LC-MS/MS method has been developed for the simultaneous analysis of polygala acid, senegenin and 3,6'-disinapoylsucrose (DSS) in rat plasma. The method was applied to the pharmacokinetics studies of polygala acid, senegenin and DSS. The analysis was carried out on an Agilent Eclipse plus C18 reversed-phase column (100 × 4.6 mm, 3.5 µm) by gradient elution with methanol and ammonia (0.01%, v/v). The flow rate was 0.4 mL/min. All analytes including internal standard (IS) were monitored by selected reaction monitoring with an electrospray ionization source. Linear responses were obtained for polygala acid and DSS ranging from 2.5 to 2000 ng/mL, and senegenin ranging from 5 to 2000 ng/mL. The intra- and inter-day precisions (relative standard deviation) were <11.34 and 8.99%. The extraction recovery ranged from 70.89 ± 4.60 to 88.49 ± 3.26%, and that for the IS was 77.23 ± 3.68%. Stability studies showed that polygala acid, senegenin and DSS are stable during the preparation and analytical process. The validated method was successfully used to determine the concentration-time profiles of polygala acid, senegenin and DSS.