In-vitro and In-vivo Identification, Absorbtion and Metabolism Network Analysis of Filifolium sibiricum Flavonoids Dropping Pill by UHPLC-Q-TOF-MS.

BACKGROUND: Filifolium sibiricum flavonoids dropping pill (FSFp), a unique Chinese Filifolii sibirici herba extract preparation, has the potential as an alternative therapy against S. aureus infection (SA) and antiinfection. However, its chemical composition and in vivo metabolism characteristics remain unknown, which limits its clinical application. METHODS: Here, we aimed to understand the in vitro and in vivo material basis of FSFp. Ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) was used to identify chemicals in FSFp as well as its phase I and phase II reaction metabolites in plasma, urine and feces. RESULTS: A total of 38 chemicals were characterized in FSFp, including 22 flavonoids, 10 organic acids, 3 chromones, 1 aromatic ketone, 1 coumarin, and 1 ligan. After analysis of the drugged bio-samples, a total of 21 compounds were found in urine, and 16 of them were found in feces, but only one was found in plasma. In addition, 56 FSFp-related metabolites were characterized, of which 56 were in urine, 4 in feces, and 8 in plasma. CONCLUSION: This is the first comprehensive research of FSFp on chemical constituents and metabolic profiles. It was expected that this study would offer reliable support for further investigation of FSFp.

Simultaneous Determination of Rivaroxaban and Enalapril in Rat Plasma by UPLC-MS/MS and Its Application to A Pharmacokinetic Interaction Study.

BACKGROUND AND OBJECTIVES: There have been no animal experiments and clinical studies on the pharmacokinetic interaction between rivaroxaban and enalapril. To investigate whether a potential pharmacokinetic interaction is present between rivaroxaban and enalapril, a rapid and sensitive Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine the concentration of rivaroxaban and enalapril in rat plasma and was then applied to a pharmacokinetic interaction study. METHODS: The analytes were separated on an Acquity UPLC BEH C18 chromatography column (2.1 × 50 mm, 1.7 µm) with acetonitrile and 0.1% formic acid as the mobile phase with gradient elution. The mass spectrometer was operated in multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of 436.1 → 145.1 m/z for rivaroxaban, 377.3 → 234.2 m/z for enalapril and 285.2 → 193.1 m/z for diazepam (IS). RESULTS: The method was validated over the concentration range of 1.0-200 ng/mL for rivaroxaban and 0.5-100 ng/mL for enalapril. The intra- and inter-day precision and accuracy of the quality control (QC) samples exhibited relative standard deviations (RSD) < 9.4% and the accuracy values ranged from - 8.3 to 9.6%. After co-administration of rivaroxaban and enalapril, the maximum plasma concentration (Cmax) and area under the systemic drug concentration-time curve from time 0 to infinity (AUC0-∞) of rivaroxaban were significantly increased by 19.6% (p < 0.05) and 21.3% (p < 0.05), respectively. On the contrary, the plasma clearance rate (CL/F) of rivaroxaban and enalapril was significantly decreased by 17.8% (p < 0.05) and 23.8% (p < 0.05), respectively. CONCLUSIONS: The UPLC-MS/MS method was successfully applied to simultaneous determination of rivaroxaban and enalapril in rat plasma and applied to study the pharmacokinetic interaction between rivaroxaban and enalapril. The co-administration of rivaroxaban and enalapril resulted in a significant drug interaction in rats.