Determination of cefoperazone and sulbactam in serum by HPLC-MS/MS: An adapted method for therapeutic drug monitoring in children.

A rapid, accurate and specific high-performance liquid chromatography-tandem mass spectrometry method has been validated for the simultaneous determination of cefoperazone and sulbactam in a small volume sample for children. A Shim-pack XR-ODS C18 column with gradient elution of water (0.1% formic acid) and acetonitrile (0.1% formic acid) solution was used for separation at a flow rate of 0.3 mL/min. The calibration curves of two analytes in serum showed excellent linearity over the concentration ranges of 0.03-10 µg/mL for cefoperazone, and 0.01-3 µg/mL for sulbactam, respectively. This method involves simple sample preparation steps and was validated according to standard US Food and Drug Administration and European Medicines Agency guidelines in terms of selectivity, linearity, detection limits, matrix effects, accuracy, precision, recovery and stability. This assay can be easily implemented in clinical practice to determine concentrations of cefoperazone and sulbactam in children.