Sensitive Voltammetric Determination of Niclosamide at a disposable pencil graphite electrode

Niclosamide (NA), an effective drug against tapeworm infections, was electrochemically studied using a pencil graphite electrode (PGE). A low-cost sensitive and selective procedure was developed for determination of NA by recording differential pulse voltammograms of NA in pH 7.0 Britton-Robinson buffer solution containing 0.1 M KCl and 30% DMF at the PGE. The PGE displayed very good electrochemical behavior with significant enhancement of the peak current compared to a glassy carbon electrode. Moreover, results obtained from the differential pulse voltammograms show that PGE offers a disposable, low cost, selective and sensitive electrochemical sensor for determination of NA. Under experimental conditions, the PGE had a linear response range from 0.05 mu M to 10 mu M NA with a detection limit of 0.015 mu M (based on 3(sb)). A relative standard deviation of 0.57% was obtained for five successive determinations of 5 mu M NA, which indicate acceptable repeatability. This voltammetric method was successfully applied to the direct determination of NA in tablets. No interference from the tablet excipients was encountered. (C) 2014 Elsevier Ltd. All rights reserved.