A low-volume LC/MS method for highly sensitive monitoring of phenoxymethylpenicillin, benzylpenicillin, and probenecid in human serum.

Riezk, Alaa ORCID: 0000-0002-1829-5770, Wilson, Richard C ORCID: 0000-0002-3275-6932, Cass, Anthony EG ORCID: 0000-0001-8881-4786, Holmes, Alison H ORCID: 0000-0001-5554-5743 and Rawson, Timothy M ORCID: 0000-0002-2630-9722 (2024) A low-volume LC/MS method for highly sensitive monitoring of phenoxymethylpenicillin, benzylpenicillin, and probenecid in human serum. Analytical methods : advancing methods and applications, 16 (4). pp. 558-565. ISSN 1759-9660, 1759-9679

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Official URL: https://doi.org/10.1039/d3ay01816d

Abstract

Background: The optimization of antimicrobial dosing plays a crucial role in improving the likelihood of achieving therapeutic success while reducing the risks associated with toxicity and antimicrobial resistance. Probenecid has shown significant potential in enhancing the serum exposure of phenoxymethylpenicillin, thereby allowing for lower doses of phenoxymethylpenicillin to achieve similar pharmacokinetic/pharmacodynamic (PK/PD) targets. We developed a triple quadrupole liquid chromatography mass spectrometry (TQ LC/MS) analysis of, phenoxymethylpenicillin, benzylpenicillin and probenecid using benzylpenicillin-d7 and probenecid-d14 as IS in single low-volumes of human serum, with improved limit of quantification to support therapeutic drug monitoring. Methods: Sample clean-up was performed by protein precipitation using acetonitrile. Reverse phase chromatography was performed using TQ LC/MS. The mobile phase consisted of 55% methanol in water + 0.1% formic acid, with a flow rate of 0.4 mL min-1. Antibiotic stability was assessed at different temperatures. Results: Chromatographic separation was achieved within 2 minutes, allowing simultaneous measurement of phenoxymethylpenicillin, benzylpenicillin and probenecid in a single 15 μL blood sample. Validation indicated linearity over the range 0.0015-10 mg L-1, with accuracy of 96-102% and a LLOQ of 0.01 mg L-1. All drugs demonstrated good stability under different storage conditions. Conclusion: The developed method is simple, rapid, accurate and clinically applicable for the quantification of phenoxymethylpenicillin, benzylpenicillin and probenecid in tandem.

Item Type:	Article
Uncontrolled Keywords:	Humans, Penicillin G, Penicillin V, Probenecid, Anti-Bacterial Agents, Tandem Mass Spectrometry
Depositing User:	Symplectic Admin
Date Deposited:	19 Aug 2024 14:33
Last Modified:	06 Dec 2024 17:44
DOI:	10.1039/d3ay01816d
Open Access URL:	https://doi.org/10.1039/D3AY01816D
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3183882