Voltammetric analysis of cephalexin and cefazolin in pharmaceutical formulations and biological samples

This study presents the use of disposable pencil graphite electrode to investigate the electrochemical behaviors and voltammetric determination of cephalexin and cefazolin in phosphate buffer at different pH values (4.5-6.0). Sample analysis was performed in phosphate buffer at the optimum medium determined for each sample. Validation parameters were studied to show the correctness, sensitivity, and consistency of the method developed for the cephalosporins. It was concluded that disposable pencil graphite electrode could be used effectively in the determination of cephalosporins. The limits of detection (LOD) (S/N=3) were found to be 0.117 mM and 0.293 mM, for cephalexin and cefazolin, respectively. The analysis of these compounds in pharmaceutical formulations and in human blood serum and urine samples was carried out at defined optimum conditions.