CATHODIC STRIPPING VOLTAMMETRIC DETERMINATION OF ORGANIC HALIDES IN DRUG DISSOLUTION STUDIES

A method has been developed to analyze therapeutically active organic hydrochlorides and hydrobromides In drug dissolution studies by cathodic stripping voltammetry. Results on tablets are accurate at concentrations of 10-5 and 5X10-6 M for hydrochlorides and hydrobromides with coefficients of variation of 3.1 and 2.9%, respectively. Problems associated with halide monolayer formation on hanging mercury drop electrodes are discussed, by presaturating the supporting electrolyte with mercurous halide limits of detection of 10-6 and 2X10-7 M for chloride and bromide, respectively, are obtained in 0.05 M nitric acid/potassium nitrate. The effects of 17 common pharmaceutical excipients are studied and the method is shown to be an order of magnitude more sensitive than UV spectrophotometry for drugs with molar extinction coefficients of 2000 m2 M-1. Applications of dc polarography, cyclic voltammetry, a mercury-coated glassy carbon electrode are also discussed. © 1979, American Chemical Society. All rights reserved.