Development of a UFLC–MS/MS method for simultaneous determination of six lignans of Schisandra chinensis (Turcz.) Baill. in rat plasma and its application to a comparative pharmacokinetic study in normal and insomnic rats

Schisandra chinensis (Turcz.) Baill., a traditional Chinese medicine, has been used for treating insomnia for centuries. This paper was designed to study on the plasma pharmacokinetic for its absorption process, and to compare the pharmacokinetics of its active ingredients in normal and insomnic rats orally administrated with the prescription. Therefore, an efficient, sensitive and selective ultra fast liquid chromatography/tandem mass spectrometry (UFLC–MS/MS) method for the simultaneous determination of six sedative and hypnotic lignans (schisandrin, schisandrol B, schisantherin A, deoxyshisandrin, γ-schisandrin and gomisin N) of Schisandra chinensis (Turcz.) Baill. in rat plasma has been developed and validated. The analysis was performed on a Shim-pack XR-ODS column (75mm×3.0mm, 2.2μm) using gradient elution with the mobile phase consisting of acetonitrile and 0.1% formic acid waterat a flow rate of 0.4ml/min. The detection of the analytes was performed on 4000Q UFLC–MS/MS system with turbo ion spray source in the positive ion and multiple reaction-monitoring mode. The method was validated in plasma samples, which showed good linearity over a wide concentration range (r²>0.99), and obtained lower limits of quantification were 10, 1.2, 1.2, 1.2, 1.0 and 1.2ngmL⁻¹ for the analytes. The intra- and inter-day assay variability was less than 15% for all analytes. The mean extraction recoveries of analytes and IS from rats plasma were all more than 85.0%. The validated method has been successfully applied to comparing pharmacokinetic profiles of analytes in rat plasma. The results indicated that significant difference in pharmacokinetic parameters of the analytes was observed between two groups, while absorptions of these analytes in insomnic group were all significantly higher than those in normal group.