Determination of Terbinafine at a Boron-Doped Diamond (BDD) Electrode Modified with Polypyrrole and γ-Cyclodextrin by Square Wave Voltammetry (SWV)

This work involved the determination of the antifungal agent, terbinafine (TR) using a boron-doped diamond electrode (BDD) that was modified with polypyrrole in the presence of cyclodextrin. The obtained modified layer was overoxidized and was used to develop a novel, sensitive method for terbinafine. Scan rate measurements confirmed the diffusion character of the recorded currents. Terbinafine was irreversibly oxidized, producing a well-defined peak at +1.05 V (versus the saturated calomel electrode) in Britton-Robinson (B-R) buffer at pH 6.09. Square wave voltammetry was employed to study the relationship between current and terbinafine concentration in the optimized conditions. A linear range for terbinafine determination was obtained between 7.04 x 10(-8) and 9.09 x 10(-7 )mol/L with a limit of detection of 2.11 x 10(-8 )mol/L and good repeatability (2.56%, n = 6 measurements, at 3.7 x 10(-7 )mol/L). The procedure was employed to determine terbinafine in pharmaceutical preparations. The recovery values between 97.37 and 102.16% demonstrate the accuracy of the developed protocol.