Voltammetric determination of nitroimidazopyran drug candidate for the treatment of tuberculosis

PA-824 (2-nitro-6-(4-trifluoromethoxy-benzyloxy)-6,7-dihydro-5H-imidazo [2, 1-b][1,3]oxazine) a nitroimidazopyran drug candidate for the treatment of t uberculosis was electrochemically studied with the aims of to propose a new electroanalytical method and to investigate the potential of an electroche mical system to mimic phase I reduction metabolism in PA-824. The electroch emical behavior was studied using tast polarography, differential pulse pol arography. differential pulse voltammetry and cyclic voltammetry. PA-824 wa s electrochemically reducible showing one reduction peak due to the four-el ectron reduction of the nitro group to form the hydroxylamine derivative. A method for the determination of PA-824 by differential pulse polarography and differential pulse voltammetry at pH 7 were proposed. The differential pulse polarography method has adequate accuracy and precise with a mean rec overy of 101.11% and a standard relative deviation of 2.27%. The detection limit was 2.23 x 10(-7) M. Furthermore. for comparative purposes an alterna tive differential pulse voltammetry and UV spectrophotometric methods were developed. On the other hand. from the electrochemical point of view, PA-82 4 shows similar reduction capabilities that metronidazole supporting the hy pothesis that both drugs could share a similar reductive metabolism.