Determination of Ecliptasaponin A in Rat Plasma by using UPLC-MS/MS and its Pharmacokinetics Application

Eclipta (Eclipta prostrata L.) is a widely used Chinese medicinal plant that mainly contains saponins. Ultra-high performance liquid chromatography tandem mass spectrometry is a rapid, selective and sensitive method for the determination and pharmacokinetic investigation of ecliptasaponin A in rat plasma with notoginsenoside R1 as the internal standard (IS). Plasma sample preparation was achieved through a one-step liquid-liquid extraction method. Plasma samples were analyzed by using a COSMOSIL 5C18-MS-II packed column (2.0 x 50 mm, 5 mu m) with a line gradient elution using acetonitrile and 0.1 % acetic acid as the mobile phase. All analytes and notoginsenoside R1 were detected in negative ionization mode by using multiple reaction monitoring (MRM) of the transitions at m/z 633.2 -> 587.2 (ecliptasaponin A) and m/z 931.6 -> 637.2 (IS), respectively. The method was linear for all analytes over the investigated ranges, with all correlation coefficients > 0.997. The intra- and inter-day precisions (RSD, %) were < 9.0 %, and accuracy (RE, %) ranged from 5.6 to 11.3 %, which were within the acceptable limits. The mean extraction recoveries of the analytes from rat plasma were within the range of 96.9-104.4 %, and no notable matrix effect was observed. This validated method was successfully utilized in a pharmacokinetic study of an ecliptasaponin A extract via oral and intravenous administration.