Spectrophotometric determination of cephradine and cefadroxil using 2,3- dichloro-5,6-dicyano-1,4-benzoquinone reagent

Abstract EN

A spectrophotometric method is described for the determination of cephradine and cefadroxil in their pure forms as well as in some pharmaceutical dosage forms.

The method is based on the formation of a charge-transfer complex between 2, 3-dichloro-5, 6-dicyano-1,4-benzoquinone (DDQ) as ?-acceptor and the studied drugs as n-donors in aqueous medium in the presence of borate buffer solution of pH9.

The spectra of the complexes show absorption maxima at 342 and 338 nm with the apparent molar absorptivities of 9.61×103 and 1.52 × 104L.mol-1cm-1 for cephradine and cefadroxil respectively.

Beer’s law is obeyed in the concentration ranges of 1.2-17 and 1.6-20?g / ml.

The mean percent recoveries are 100.2% and 100.5% and the formation constant(K) values of the charge transfer complexes are 5.57 × 105 and 5.40 × 105l.mol-1 for the above drugs respectively.

The results for assay of cephradine and cefadroxil in their pharmaceutical preparations suggested that there is no interference, which are present in commercial dosage forms which is compared favorably with the result of the standard addition procedure.