Objective: The aim of this study was to develop a simple, reliable voltammetric method and its validation for determination of nonsteroidal anti-inflammatory drug diclofenac (DFC).
Methods: The proposed method was based on electro-oxidation of DFC at poly (erichrome black T) modified glassy carbon electrode (PEBT/GCE) in 0.2 M phosphate buffer solution of pH 7.0. Cyclic voltammetry and differential pulse voltammetric techniques were employed to study electro-oxidation behavior. Under the optimal conditions, variations of EBT concentration, effect of pH, scan rate on the oxidation of DFC was studied.
Results: A well-defined oxidation peak at about +0.59 V vs. standard calomel electrode was observed for voltammetric detection of DFC. pH effect shows the participation of an equal number of protons and electrons in the mechanism. The relation between a logarithm of peak current with the logarithm of scan rate indicated adsorption controlled behavior of electrode process. Concentration variations show a good linear response in the range 0.05 µM to 40 µM with the detection limit of 5.25 × 10-8 M.
Conclusion: The prepared sensor exhibited good selectivity, sensitivity, and stability for the detection of DFC in the pharmaceutical dosage form and real samples. The developed method could possibly be adopted for pharmacokinetic studies and also in clinical and quality control laboratories where time and economy were important.
Electro-Oxidation of Ciclopirox Olamine at a Glassy Carbon Electrode
