Simultaneous Determination of Seven Components in Rat Plasma by the UPLC-MS/MS Method and Application of Pharmacokinetic Studies to SimiaoYong'an Decoction.

SimiaoYong'an Decoction (SYD) is a classical traditional Chinese prescription that is used for the treatment of gangrene, heat-clearing, detoxification and pain alleviation. We developed a sensitive ultra-performance liquid chromatography-tandem mass spectrum (UPLC-MS/MS) method for the simultaneous determination of seven major active ingredients of SYD extract (i.e., harpagide, chlorogenic acid, sweroside, loganin, liquiritin, angoroside C and harpagoside) in rat plasma. The preliminary steps in the plasma analysis were the addition of an internal standard such as linarin, followed by protein precipitation with methanol. Separation of the active ingredients was performed on an ACQUITY UPLC® BEH C18 column (100 mm × 2.1 mm, 1.7 μm) at a flow rate of 0.2 mL/min with methanol/water 0.1% formic acid aqueous (V/V) as the mobile phase. Detection was performed on a triple quadrupole tandem MS (QqQ-MS) via negative ion electrospray ionization in multiple reactions monitoring (MRM) mode. All calibration curves showed good linearity (r > 0.99) over the concentration range with a low limit of quantification between 0.029 and 5.813 ng/mL. Precision was evaluated by intra-day and inter-day assays, and the percentages of the RSD were all within 8.1%. The extraction efficiency and matrix effect were 80.6-113.6% and 82.9-99.5%, respectively. The validated method was successfully applied to a pharmacokinetic study in rats after oral administration of SYD extract and the corresponding single and combined traditional Chinese medicines (TCMs). The pharmacokinetic properties of the seven ingredients showed dynamic changes due to counteraction among the different coexisting components. The established approach has proven useful in the study of the active constituents in a traditional Chinese prescription.