Spectrofluorometric Determination of Cephalexin in Pharmaceutical Preparations and Spiked Human Urine Using 2‐Cyanoacetamide

Abstract

A simple, accurate, sensitive, and validated method was developed for the spectrofluorometric determination of cephalexin. The method involves the reaction of cephalexin with 2‐cyanoacetamide in presence of 33% ammonia solution. The formed fluorescent product exhibited maximum fluorescence intensity at λ 439 nm, after excitation at λ 339 nm. Different experimental parameters affecting the derivatization reaction were carefully studied and incorporated in the procedure. Under the described conditions, the proposed method was linear over the concentration range 0.04–0.4 µg/mL. The average percent found was 99.6±0.9%. The LOD was 7.76 ng/mL. The proposed method was applied for determination of cephalexin in pharmaceutical preparations as well as in spiked human urine. A mechanism of the reaction is postulated.