Simultaneous determination of cefepime and L-arginine in injections by second-derivative spectrophotometry

A simple spectrophotometric assay for the determination of cefepime and L-arginine in injections is described. Since zero-order spectra showed considerable overlap, second-derivative spectrophotometry was used to enhance the spectral details. A linear relationship between second-derivative amplitude and concentration of each compound was found. Beer's law was obeyed up to 50 and 22 micrograms ml-1 of cefepime and arginine, respectively, in the second-derivative mode. Detection limits were 0.31 and 0.58 micrograms ml-1 for cefepime and arginine, respectively. The method, which is rapid, simple and does not require any separation step, has been successfully applied to the assay of commercial injections containing cefepime and arginine.