Development and Validation of UHPLC-MS/MS for Simultaneous Determination of Scutellarin and Salicylic Acid in Rat Plasma: Application to Herb-Drug Pharmacokinetic Interaction Study

Dengzhanxixin injection (DI) product has been clinically proven to be effective for treating cardio-cerebrovascular disease. Furthermore, herb-drug interactions between the DI product and drugs that are commonly co-administered, such as aspirin, must be explored to ensure safe clinical use. A reliable ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for simultaneous determination of scutellarin and salicylic acid (SA) in rat plasma. The proposed method has been successfully applied to pharmacokinetic studies on analytes in rats after i.g. administration of aspirin alone, i.v. administration of DI alone or a combination of both (i.g.: 10 mg kg(-1) aspirin, i.v.: 4 mL kg(-1) DI). Both SA and scutellarin exhibited a two-compartment model pharmacokinetic profile. Aspirin did not change the concentration-time course for scutellarin, but DI decreased the peak plasma concentration and the area under the SA curve. This study indicates that co-administration of aspirin and DI can cause an apparent herb-drug pharmacokinetic interaction in rats.