HPLC METHOD OF ANALYSIS OF CEPHADROXIL AND ITS APPLICATION IN BIOAVAILABILITY STUDIES

A rapid, simple, sensitive and accurate HPLC method, for the determina tion of cephadroxil in urine, is presented using paracetamol as an int ernal 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 wer e eluted from a 10-mum, 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 nm. The anal ysis of each sample required 6 min. The detection limit for cephadroxi l in urine is 1.2 mug/ml. This method was applied to determine the bio availability of cephadroxil after administration of an oral, single, d ose of two commercially available capsule brands to eight healthy volu nteers in a crossover design. Urine samples were collected over a 12-h period.