Determination of ranitidine in drugs using a mercury coated platinum ultramicroelectrode and hanging mercury dropping electrode

Abstract

The voltammetric behavior of ranitidine has been studied in aqueous media with a mercury coated platinum ultramicroelectrode (Hg-UME) and by HMDE. The LSV curves for the electroreduction of ranitidine showed that the compound presents two reduction waves in pH < 4.0 and only one in pH > 4.0, the observed waves being attributed to the reduction of the nitro group to hydroxylamine. A linear relation between the current peak or limiting current and the ranitidine concentration using HMDE or Hg-UME was observed, demonstrating that these ultramicroelectrodes can be used in the analytical determination of ranitidine. An alternative and more sensitive methodology for the analytical determination of ranitidine by SWV was also developed, with a detection limit of 3.5 × 10-8 mol L-1 (or 11 μg L-1). The apparent recovery (AR) studies proved the accuracy and precision of the assay developed. The excipients found in comercial Antak tablets (Glaxo Wellcome) and the generic from EMS® do not interfere in the determination.