Quantification of Diclofenac at Trace Levels in Pharmaceutical and Urine Samples Using Kinetic Spectrophotometric Method

Diclofenac, a non-steroidal anti-inflammatory drug, is prescribed to reduce inflammation and as an analgesic reducing pain in certain conditions. In this study, a sensitive reaction system for quantitative determination of diclofenac was introduced. The method is based on the catalytic effect of diclofenac on the Orange G-bromate reaction system. The change in absorbance was followed spectrophotometrically as a criterion of the oxidation reaction progress at 478.5 nm. The effective reaction variables were optimized. Under optimized experimental conditions, calibration curve was linear over the range 0.035 – 2.7 mg/l and the detection limit (3sb/m) was 0.014 mg/l for five replicate determinations of blank signal. The interfering effect of various species was also investigated. The developed procedure was applied for the determination of diclofenac in pharmaceutical and biological samples satisfactorily.