A SELECTIVE SPECTROFLUOROMETRIC METHOD FOR THE DETERMINATION OF SOME ALPHA-AMINOCEPHALOSPORINS IN FORMULATIONS AND BIOLOGICAL-FLUIDS

A selective, highly sensitive fluorimetric method is described for the determination of three alpha aminocephalosporins, namely cephalexin, cefaclor and cephradine. Other cephalosporins free from the amino grou p did not interfere with the assay. The proposed method involves acid- hydrolysis of the drugs and subsequent alkalinization before measureme nt. The different experimental parameters affecting the fluorescence i ntensity were carefully studied and incorporated into the procedure. T he method permits the determination of 0.02-0.40, 0.04-0.60 and 0.08-0 .80 ug.ml(-1) for cephalexin, cefaclor and cephradine respectively wit h minimum detectability of 0.2 ng.ml(-I) for all cephalosporins. The p roposed method was successfully applied to the determination of these drugs in formulations and biological fluids. The advantages of the des cribed method over other existing methods were discussed.A route for t he reaction pathway proposed.