High-performance liquid chromatographic determination of cefepime in humanplasma and in urine and dialysis fluid using a column-switching technique

A high-performance liquid chromatographic method with UV absorbance was dev eloped for the analysis of cefepime in human plasma and urine, and in dialy sis fluid. Detection was performed at 280 nm. The assay procedure for cefep ime in plasma involves the addition of an internal standard (cefpirome) fol lowed by treatment of the samples with trichloracetic acid, acetonitrile an d dichloromethane. To quantify cefepime in diluted urine (1:20) and in the dialysis fluid, samples spiked with the internal standard (cefpirome) were analysed using a column-switching technique. The HPLC column, Nucleosil C-1 8, was equilibrated with an eluent mixture composed of acetonitrile-ammoniu m acetate (pH 4). Linear detector responses were observed for the calibrati on curve standards in the range 0.5 to 100 mug/ml, which spans what is curr ently thought to be the clinically relevant range for cefepime concentratio ns in body fluids. The limit of quantification was 0.5 mug/ml in the three matrices. Extraction recoveries proved to be more than 84%. Precision, expr essed as %RSD, was in the range 1.5 to 9%. Accuracy ranged from 93 to 105%. This method was used to follow the time course of the concentration of cef epime in plasma, urine and dialysate outlet samples after a 10-min infusion period of 2 g of this drug in patients with acute renal failure undergoing hemodiafiltration. (C) 2001 Elsevier Science B.V. All rights reserved.