Abstract
The stabilities of amoxicillin (16 micrograms/ml) and clavulanate (8 micrograms/ml), alone and in combination in BACTEC medium (Middlebrook 7H12B medium), were determined by high-performance liquid chromatography (HPLC) and bioassay. By HPLC, the half-life of amoxicillin (trihydrate and sodium) in combination with clavulanate in nonradiolabelled 7H12B medium was 6.7 days, whereas the half-life of clavulanate in combination with amoxicillin was 2.0 days. By bioassay, the half-lives of amoxicillin trihydrate and clavulanate in radiolabelled 7H12B medium were comparable (7 and 2 days, respectively) to those determined by HPLC. When clavulanate was tested alone, the half-life was determined to be 1.88 days by HPLC and 1.87 days by bioassay. The relatively short half-life of clavulanate can be adjusted by a procedure of "topping up," or adding one-half the concentration of clavulanate every second day, in order to allow accurate amoxicillin-clavulanate MIC testing with the BACTEC mycobacterial susceptibility system.
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Selected References
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- Foulstone M., Reading C. Assay of amoxicillin and clavulanic acid, the components of Augmentin, in biological fluids with high-performance liquid chromatography. Antimicrob Agents Chemother. 1982 Nov;22(5):753–762. doi: 10.1128/aac.22.5.753. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee C. N., Heifets L. B. Determination of minimal inhibitory concentrations of antituberculosis drugs by radiometric and conventional methods. Am Rev Respir Dis. 1987 Aug;136(2):349–352. doi: 10.1164/ajrccm/136.2.349. [DOI] [PubMed] [Google Scholar]
- Lee T. L., Brooks M. A. High-performance liquid chromatographic determination of amoxicillin in human plasma using a bonded-phase extraction. J Chromatogr. 1984 Mar 9;306:429–435. doi: 10.1016/s0378-4347(00)80911-1. [DOI] [PubMed] [Google Scholar]
- Watt B., Edwards J. R., Rayner A., Grindey A. J., Harris G. In vitro activity of meropenem and imipenem against mycobacteria: development of a daily antibiotic dosing schedule. Tuber Lung Dis. 1992 Jun;73(3):134–136. doi: 10.1016/0962-8479(92)90145-A. [DOI] [PubMed] [Google Scholar]