HPLC method of analysis of cephadroxil and its application in bioavailability studies

Abstract

A rapid, simple, sensitive and accurate HPLC method, for the determination of cephadroxil in urine, is presented using paracetamol as an internal standard. The urine samples were suitably diluted and an aliquot of the clear supernatant, after vortex–mixing and centrifugation, was directly injected into the column. The drug and internal standard were eluted from a 10–μm, C–8 reversed–phase column with a mobile phase consisting of phosphate buffer solution (pH 5)/acetonitrile (95:5) at a flow rate of 2 ml/min with ultraviolet detection at 280 run. The analysis of each sample required 6 min. The detection limit for cephadroxil in urine is 12 μg/ml. This method was applied to determine the bioavailability of cephadroxil after administration of an oral, single, dose of two commercially available capsule brands to eight healthy volunteers in a crossover design. Urine samples were collected over a 12–h period.