The determination of cefixime 1 has clinical and analytical importance due to its broad
spectrum antimicrobial activity and stability. Cefixime is a significant member of orally active third
generation cephalosporin and has excellent activity against many pathogens. It is for first time that
we have developed a new HPLC–DAD method for analysis of imine derivative 3 of cefixime by using
reflux method at 100 C for 50 min without any buffer solution. 2 Thiophenecarboxaldehyde (2TCA)
2 was used first time as a derivatizing reagent for cefixime drug. Furthermore, separation of three components,
i.e. drug (cefixime), reagent (2TCA) and derivative was carried out using kromasil 100 C-18
(15 mm · 0.46 mm, 5 lm) column with isocratic elution of methanol: 0.1% aqueous formic acid
(70:30 v/v) with flow rate of 1 ml min1 at retention time of 1.8, 2.4 and 3.3 min, respectively; while,
total run time was 5 min. The developed method was repeatable with a relative standard deviation
(RSD) of 0.81–1.88% for imine derivative. The limit of detection and quantification of imine derivative
3 were obtained within the range of 0.132–0.401 lg ml1 and compared with cefixime drug as 0.30–
0.90 lg ml1, respectively. However, the formation of imine derivative 3 was confirmed by comparing
peak height, retention time and spectral changes. The method is rapid, simple, very stable and accurate
for the separation and determination of imine derivative 3 of cefixime 1.