Spectrophotometric determination of cefadroxil in drug formulations using flow injection analysis

A flow injection analysis method for the determination of cefadroxil is pro posed. The method is based on the hydrolysis of cefadroxil in sodium hydrox ide solution followed by treatment with 1,4-phenylenediamine and Fe(III) in sulphuric acid solution to produce a violet color which has a maximum abso rption at 600 nn. Variables such as acidity, reagent concentrations, flowra te of reagents and other Fl parameters were optimized to produce the most s ensitive and reproducible results. The calibration graph is linear between 80 - 320 mg/l. The detection limit is 40 mg/l with a relative standard devi ation, RSD (n=6) of 1.8%. The proposed method, combining the advantages of speed and accuracy was applied to the determination of cefadroxil in pharma ceutical preparations. The results have been compared with those obtained u sing HPLC method (USP-procedure). Excellent agreement between the results o f the proposed method and the HPLC method was observed.