Indirect Spectrophotometric Methods for the Determination of Cefadroxil in its Pure and Pharmaceutical Preparations

Two spectrophotometric methods were described for the determination of cefadroxil in pure form and in its pharmaceutical preparations. They were based on the oxidation-reduction reaction between iron (III) and cefadroxil, the liberated Fe+2 is then reacted with 1,10-phenathroline (method I) or 2,2`-bipyridyl (method II) in acidic medium, the colored(red) complexes absorbed at 510 and 521 nm, respectively. Applying the optimum working conditions, cefadroxil can be determined over the concentration range of 0.5-5 and 0.5-6 μg.ml-1 with molar absorptivities of 1.141x105 and 6.308×104 l. mol-1 .cm-1 for method I and method II, respectively. The proposed methods were applied successfully to the determination of cefadroxil in various pharmaceutical preparations.