Simultaneous determination of five β-lactam antibiotics (cefepim, ceftazidim, cefuroxim, meropenem and piperacillin) in human plasma by high-performance liquid chromatography with ultraviolet detection

Monitoring of plasma antibiotic drugs is useful for better clinical management in infected patients, particularly in intensive care units. A simple and sensitive high-performance liquid chromatography (HPLC) method with ultraviolet (UV) detection has been developed and validated for simultaneous quantification of five beta-lactam. antibiotics in human plasma: cefepim, ceftazidim, cefuroxim, meropenem and piperacillin. The plasma sample, after spiked with ceforanid as an internal standard (IS), was submitted to a solid-phase extraction (SPE) prior to HPLC analysis. A chromatographic separation was achieved on a C8 symmetry column with a mobile phase consisting of an acetonitrile and phosphate buffer (pH 7.4) mixture in a gradient mode. Detection was carried out at a wavelength between 200 and 400 run. The method developed was linear over the concentration range of 2.5-60 mu g/ml, for each antibiotic in the plasma samples. Accuracy ranged from 93.2 to 107. 1 % and precision was between 0.9 and 12.2%. The method has been applied to plasma samples obtained from patients treated with beta-lactam antibiotics and is appropriated for easy determination of plasma concentrations for therapeutic monitoring applications.