Spectrophotometric Determination of Cephadroxil by Coupling with Diazotized p–Nitroaniline – Application to Pharmaceutical preparations


A new spectrophotometric method for the assay of micro amount of cephadroxil in aqueous solution has been worked out. The method is based on the coupling of cephadroxil with diazotized p–nitroaniline in basic medium. The azo dye formed is water–soluble, stable, and shows maximum absorption at 479 nm, Beer’s law is obeyed over the range 10-200 ppm with a molar absorptivity of 2.216104 l.mol-1.cm-1, relative error of –0.761 to +0.256% and a relative standard deviation of 0.250 to % depending on the concentration. The method has been applied to determine cephadroxil in pharmaceutical preparations.