Electrochemical Evaluation of Delayed Release Behaviour of Diclofenac Sodium Tablets

Abstract

Diclofenac Sodium is a commonly used electro active anti-inflammatory drug. There are various analytical techniques to detect Diclofenac Sodium active ingredient including cyclic voltammetry. Cyclic voltammetry was used with different kinds of modified electrodes. In this project, drug release action of Diclofenac Sodium is detected by introducing bare Platinum electrode as the working electrode instead of the modified electrodes. Carbon and silver/silver chloride electrodes are counting and reference electrodes respectively. Platinum electrode is characterized by using 0.5 mM potassium ferrocyanide in a 0.1 M Potassium chloride solution at different scan rates. Diclofenac Sodium dissolution medium is a phosphate buffer solution. The optimum pH value of the phosphate buffer solution for the Diclofenac Sodium dissolution is identified as 6.8. From the resultant cyclic voltammograms of current density at bare platinum electrode Vs. applied potential, the variation of drug concentration with respect to the time is analyzed. The limit of detection (LOD) of Diclofenac Sodium and the limit on quantification (LOQ) on the bare platinum electrode are 0.21 mM and 0.63 mM respectively. The limit of detection is suitable to detect the delayed release behaviour of Diclofenac Sodium. All the three selected brands take around 12 hours to reach a constant concentration. Finally, the characteristic drug release curve of delayed release drugs can be obtained from the resultant graphs of drug concentration Vs. drug dissolution time for the three selected brands. Electrochemical sensors are therefore proposed as an alternative tool for delayed release analysis in medical sciences and pharmaceutical industries.