Utility of Derivative Spectrophotometry For the Determination of Certain Cephalosporins and Their Alkali-Induced Degradation Products In Combination

Abstract

First (D₁-) and second (D₂-) derivative spectrophotometric methods have been proposed for the assay of 7 cephalosporins, each with its alkali-induced degradation product in combination. Solutions of these cephalosporins in McIlvaine's citric acid-phosphate buffer pH 7.0 were analyzed by measuring the 1st and 2nd derivative spectral response at certain wavelengths where the respective degradation products exhibit no contribution. the latter could be determined at the selected λ in the vicinity of negligible absorbance of the corresponding intact drug. Kinetic investigation of the alkaline degradation rate of cephalosporins revealed that the proposed methods were stability indicating. the different cephalosporin pharmaceutical preparations were assayed and gave results of equal accuracy (t-test)& reproducibility (F-test) with the corresponding official method of assay.

Key Words:

• First derivative spectrophotometry
• second derivative spectrophotometry
• cephalosporins
• alkali-induced degradation of cephalosporins
• pharmaceutical formulations