Real-time therapeutic drug monitoring of cefozopran in plasma using high-performance liquid chromatography with ultraviolet detection.

A simple, rapid, and precise HPLC method using ultrafiltration to remove plasma protein was developed to determine cefozopran concentrations in human plasma for real-time therapeutic drug monitoring. Plasma was separated by centrifugation at 4 degrees C from blood collected in heparinized vacuum tubes. Cefozopran and an internal standard were detected by ultraviolet absorbances at 235 nm with no interfering plasma peak. The calibration curve of cefozopran in human plasma was linear from 0.2 to 200 microg/ml. The limit of detection was 0.05 microg/ml. The assay was applied to febrile neutropenia patients in a clinical setting.