Establishment of quantitative methodology for sophoridine analysis and determination of its pharmacokinetics and bioavailability in rat

Abstract

Objective

The aim of this study is to develop a rapid and sensitive UPLC–MS/MS approach to determine the sophoridine (SOP) level in rat plasma and the pharmacokinetics of the substance.

Significance

Sophoridine is used as an anti-inflammatory, anti-virus, anti-microbial, and anti-tumor alkaloid. It is essential to explore specific detection methods for the quantitative analysis of SOP in the blood circulation.

Methods

The rat plasma samples were prepared by one-step protein precipitation with acetonitrile. Subsequently, the samples were separated by chromatography using a UPLC BEH C18 reversed-phase with an initial mobile phase of methanol and 0.1% formic acid aqueous solution. The gradient elution was performed at a fixed flow rate of 0.4 mL/min, and multiple reaction monitoring (MRM) mode with an electrospray positive ionization source was employed to detect the transitions of m/z 249.1 → 84.2 for SOP and m/z 264.3 → 69.8 for dendrobine (IS). The entire process required 3.5 min for each sample.

Results

A linear correlation was established over the range of 2–2000 ng/mL (r²≥0.9954) for SOP in rat plasma with a lower limit of quantification (LLOQ) at 2 ng/mL. The range of accuracy was tested between 94.90% and 100.80%, and the relative standard deviations (RSDs) toward both intra- and inter-day precision were <10%. Thus, this method was successfully applied to a pharmacokinetic study, and the subsequent results demonstrated a low absolute bioavailability of 2.32%.

Conclusion

The present study established a reliable method that quantified the SOP concentration in rat plasma after administering a dose of 2 mg/kg intravenously or 20 mg/kg orally.

Keywords:

• Sophoridine
• UPLC–MS/MS
• rat plasma
• pharmacokinetics
• bioavailability

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Special Project for Significant New Drug Research and Development in the Major National Science and Technology Projects of China under Grant [2020ZX09201002]; Medical Scientific Research Foundation of Zhejiang Province under Grant [2020KY641]; Research Fund for Lin He’s Academician Workstation of New Medicine and Clinical Translation under Grant [18331209]; and Zhejiang Provincial Natural Science Foundation under Grant [LY19H040006].