The Potentialities of Using a Graphite-Silicone Rubber Composite Electrode in the Determination of Propranolol

Abstract

A graphite silicone-rubber composite electrode (GSR) was used for the determination of propranolol in drug formulation. Cyclic voltammetry (CV) at the GSR presented an irreversible oxidation peak at + 0.8 V vs. SCE, in Britton Robinson (B-R) buffer pH 7.4. The quantitative determination was carried out using differential pulse voltammetry (DPV). Under optimized parameters a linear dynamic range from 5.0 to 80.6 µ mol L⁻¹ with a detection limit of 1.1 µ mol L⁻¹ was observed. A repeatability of 4.5 ± 0.1 µA (n = 10) peak current was found after 10 successive DPV voltammograms of propranolol in the same solution after surface renovations. Using the proposed electrode, propranolol was quantified in a pharmaceutical formulation with results that agreed within 95% confidence level (t-test) with those from an official method.

Keywords:

• Composite electrodes
• Propranolol
• Silicone-rubber

Notes

^a Labeled value: 40 mg/tablet.

^b |Relative error| = [(DPV−Spectrophotometric)/Spectrophotometric × 100%].