Determination of Meropenem, Ceftazidime and Piperacillin Levels in Serum and Meropenem in Cerebrospinal Fluid by Liquid Chromatography for Routine Quantification
Author(s): Stefan Günther, Andreas Reimer, Horst Vogl, Stephan Spenke, Hanns-Christian Dinges, Ann-Kristin Schubert, Leopold HJ Eberhart, Götz Geldner
Objective: Therapeutic drug monitoring (TDM) of β-lactam antibiotics is a commonly used to prevent treatment failures in critically ill patients. A quick and simple high-performance liquid chromatography (HPLC) assay for the determination of meropenem, ceftazidime and piperacillin in human serum and meopenem in cerebrospinal fluid (CSF) was developed in this study.
Methods: The method used an Atlantis? T3 5.0µm stationary phase. The mobile phase A contained water (99.4% m/m) and formic acid (0.6% m/m) (pH 2.30). The mobile phase B contained acetonitrile (93.6% m/m), water (6% m/m) and formic acid (0.4% m/m). The method used gradient elution to determine meropenem, ceftazidime and piperacillin. UV absorbance detection at 309nm, 258nm, 235nm and 260nm respectively was used. For sample preparation, an internal standard was added, and acetonitrile/methanol was added for protein precipitation.
Results: The method was investigated for linearity, specificity, accuracy, and precision. Stability of the antibiotic substances and internal standard was assessed. The retention time of meropenem was 7.222min, the single run time was 23min. Meropenem was quantified from the lower limit of quantification (0.1mg/l in serum and CSF) to the upper limit of quantification (100mg/l in serum and 25mg/l in CSF). In routine analysis of meropenem samples, a high interindividual variability of serum and CSF levels was observed and the mean CSF/serum ratio was 0.129 ± 0.092. An external validation was passed for meropenem, ceftazidime and piperacillin using the presented protocol.
Conclusion: The developed assay enable studying correlations between the applied dosage, serum concentration and CSF concentration of meropenem. Additionally, ceftazidime and piperacillin can be determined in human serum. Further studies with a higher number of samples can be performed to investigate