Separation and quantification of Azvudine in plasma of patients with COVID-19 using LC-MS/MS

Zhijun Liu; Fengying Liang; Shouhong Gao; Xiujing Zhu; Xinhua Song; Wansheng Chen; Xia Tao; Zhipeng Wang; Deduo Xu

doi:10.1016/j.jpba.2023.115736

Separation and quantification of Azvudine in plasma of patients with COVID-19 using LC-MS/MS

J Pharm Biomed Anal. 2023 Nov 30:236:115736. doi: 10.1016/j.jpba.2023.115736. Epub 2023 Sep 19.

Authors

Zhijun Liu¹, Fengying Liang², Shouhong Gao¹, Xiujing Zhu¹, Xinhua Song², Wansheng Chen², Xia Tao¹, Zhipeng Wang³, Deduo Xu⁴

Affiliations

¹ Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China; College of Traditional Chinese Medicine, Yunnan University of Traditional Chinese Medicine, Kunming, Yunnan 650500, China.
² Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China.
³ Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China. Electronic address: wangzhipeng@smmu.edu.cn.
⁴ Department of Pharmacy, Second Affiliated Hospital of Naval Medical University, Shanghai 200003, China. Electronic address: hdxudeduo@126.com.

PMID: 37776627
DOI: 10.1016/j.jpba.2023.115736

Abstract

Azvudine (FNC) is a new drug conditionally approved in 2022 for the treatment of coronavirus disease 2019 (COVID-19) in China. However, the exposure level of FNC in COVID-19 patients in clinical practice is still obscure, and there is no liquid chromatography-tandem mass spectrometry (LC-MS/MS) or LC method reported for quantifying the FNC. In this study, a simple, fast, and reliable LC-MS/MS method using L-phenylalanine-D5 (Phe-D5) as the internal standard (IS) was developed for the quantification of FNC in plasma from COVID-19 patients. After simple protein precipitation with methanol, the analyte in the supernatant was separated on Waters Atlantis® T3 (2.1 ×100 mm, 3.0 µm) column with the mobile phase consisting of acetonitrile (ACN) - aqueous solution (containing 0.03% heptafluorobutyric acid and 0.2% formic acid). The mobile phase was delivered at 0.3 mL/min in an isocratic elution program (15:85, V: V). The linear relationship of FNC was good within the calibration range of 2.0 - 2000.0 ng/mL, with the recovery of FNC ranging from 81.37% to 103.31% and the matrix effect was 94.77%- 109.83%. The short-term, long-term, and freeze-thaw stability of the FNC assessed in method was acceptable, and all other items met the requirements of validation of the biological analytical method. Finally, the method was applied to detect the exposure level of FNC in plasma samples from patients diagnosed with COVID-19, and the results, which are within the linear range of the method, showed huge inter-individual variation, supporting the significance of therapeutic drug monitoring of FNC.

Keywords: Azvudine; COVID-19; Exposure; LC/MS-MS; Therapeutic drug monitoring.