Development and validation of a measurement procedure based on ultra-high performance liquid chromatography-tandem mass spectrometry for simultaneous measurement of β-lactam antibiotic concentration in human plasma

- An UPLC-MS/MS procedure for measurement of antibiotic concentrations was developed.
- Measurement procedure/system was validated using the EMA validation guideline.
- Verification of the applicability of the procedure was performed.
- The measurement procedure developed is well suited to routine hospital practice.

BackgroundThe administration of β-lactam antibiotics in continuous infusion could let optimize the pharmacokinetic/pharmacodynamic parameters, especially in the treatment of serious bacterial infections. In this context, and also due to variability in their plasmatic concentrations, therapeutic drug monitoring (TDM) may be useful to optimize dosing and, therefore, be useful for the clinicians.Material and methodsWe developed and validated a measurement procedure based on ultra-high performance liquid chromatography-tandem mass spectrometry for simultaneous measurement of amoxicillin, ampicillin, cloxacillin, piperacillin, cefepime, ceftazidime, cefuroxime, aztreonam and meropenem concentrations in plasma. The chromatographic separation was achieved using an Acquity®-UPLC® BEH™ (2.1 × 100 mm id, 1.7 μm) reverse-phase C18 column, with a water/acetonitrile linear gradient containing 0.1% formic acid at a 0.4 mL/min flow rate. β-Lactam antibiotics and their internal standards were detected by electrospray ionization mass spectrometry in multiple reaction monitoring mode.ResultsChromatography run time was 7.0 min and β-lactam antibiotics eluted at retention times ranging between 1.08 and 1.91 min. The lower limits of quantification were between 0.50 and 1.00 mg/L. Coefficients of variation and relative bias absolute values were < 13.3% and 14.7%, respectively. Recovery values ranged from 55.7% to 84.8%. Evaluation of the matrix effect showed ion enhancement for all antibiotics. No interferences or carry-over were observed.ConclusionsOur measurement procedure could be applied to daily clinical laboratory practice to measure the concentration of β-lactam antibiotics in plasma, for instance in patients with bone and joint infections and critically ill patients.

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