SPECTROPHOTOMETERIC DETERMINATION OF SOME CEPHALOSPORINS IN

Abstract

A simple and sensitive spectrophotometric method is described for the determination of cefadroxil,cefotaxime and ceftriaxone in pure form and pharmaceutical formulations. The method is based onreacting these drugs with iron(lII) nitrate to form iron(II) which reacts with potassiumhexacyanoferrate(lII) forming a blue colored complex measurable spectrophotometrically at 777 nm.Maximum color formation was obtained through heating. Linearity was in the rang 0.6-10.0 µg ml-1, 0.1-8.0 µg ml-1 and 0.1-3.0 µg ml-1 for cefadroxil, cefotaxime and ceftriaxone, respectively with limits ofdetection of 0.1 µg ml-l for cefadroxil and 0.05 µg ml-1 for the other two drugs. Linear response wasobserved over the tested range of each drug with correlation coefficient (r) > 0.999 (n = 8-9). The meanrelative standard deviation (RSD %) of the results of within day precision and accuracy of them were ~ 1.1 % which confirmed the reproducibility of the assay technique. The method results showed insignificantdifference with those of reference methods. The method was successfully applied to the determination ofthese drugs in their dosage forms.