VOLTAMMETRIC DETERMINATION OF NITROIMIDAZOPYRAN DRUG CANDIDATE FOR THE TREATMENT OF TUBERCULOSIS

Abstract

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 tuberculosis was electrochemically studied with the aims of to propose a new electroanalytical method and to investigate the potential of an electrochemical system to mimic phase I reduction metabo lism in PA-824. The electrochemical behavior was studied using tast polarography, differential pulse polarography, differential pulse voltammetry and cyclic voltammetry. PA-824 was electrochemically reducible showing one reduction peak due to the four-electronreduction 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 recovery of 101.11% and a standard relative deviation of 2.27%. The detection limit was 2.23 × 10⁻⁷ M. Furthermore, for comparative purposes an alternative differential pulse voltammetry and UV spectrophotometric methods were developed. On the other hand, from the electrochemical point of view, PA-824 shows similar reduction capabilities that metronidazole supporting the hypothesis that both drugs could share a similar reductive metabolism.

Keywords:

• Nitroimidazopyran
• Voltammetric
• Drug analysis

ACKNOWLEDGMENTS

This work was supported by FONDECYT, Grant No 8000016. C.Y Thanks FONDECYT for a post-doctoral project N°3000043. We also acknowledge PathoGenesis Corporation (Seattle, USA) for providing PA-824 pure.