VOLTAMMETRIC BEHAVIOR OF CAPTOPRIL AND ITS POLAROGRAPHIC-DETERMINATION IN PHARMACEUTICAL FORMS

Captopril, a potent antihypertensive agent, produces an anodic polarographic peak due to the reaction of its thiol group with the mercury electrode according to the following well-known general pathway for thiol group: RSH + Hg <-> RSHg + H+ + e-The polarographic response is influenced by strong adsorption of reactant, however, the peak current shows a linear dependence with captopril concentration in a wide range. A d.p. polarographic method in order to quantify captopril in commercial tablets is proposed and its result is compared with an UV spectrophotometric method at 210 nm.