Pharmacokinetic Study of the Main Components of Tanreqing Capsules and Tanreqing Injections in beagles by liquid chromatography–tandem mass spectrometry

Abstract

Background Tanreqing capsules (TRQCs) and Tanreqing injections (TRQIs) are traditional Chinese medicine compound preparations that are widely used in the treatment of respiratory diseases. Although the ingredients of the two formulations are the same, differences in the way they are metabolized may affect their relative efficacy. In this study, a simple, rapid, and sensitive liquid chromatography–tandem mass spectrometry (LC-MS/MS) method was developed for simultaneous quantification of the main components of Tanreqing, which include chlorogenic acid, ursodeoxycholic acid, chenodeoxycholic acid, and baicalin, in beagle dog plasma to compare the pharmacokinetic parameters resulting from TRQI and TRQC administration. Method Plasma samples were pretreated with protein precipitation. Chromatographic separation was performed on a Waters Acquity UPLC HSS T3 (2.1 × 100 mm, 1.8 µm) column using a gradient elution with (A) 0.1% (v/v) formic acid aqueous solution and (B) acetonitrile. Six healthy beagles were divided into two groups, and a crossover, comparative pharmacokinetic study of TRQC (0.09g/kg) and TRQI (0.5 mL/kg) after a single-dose administration or daily doses over 7 days was carried out. One group was administrated a single dose of TRQC and followed continuously for 7 days, whereas the other group was treated with TRQI in the same way. Results The major pharmacokinetic parameters of the four compounds were not significantly different between the two formulations (P > 0.05). Conclusions The measured levels of the four major components of TRQCs and TRQIs were consistent in these dogs, providing a reference for the clinical application of TRQCs instead of TRQIs.