Quim. Nova, Vol. 31, No. 2, 349-352, 2008 DETERMINAÇÃO CONDUTOMÉTRICA DE CAPTOPRIL EM FORMULAÇÕES FARMACÊUTICAS UTILIZANDO SULFATO DE COBRE(II) COMO TITULANTE Bruna Cláudia Lourenção, Luiz Humberto Marcolino-Junior e Orlando Fatibello-Filho* Departamento de Química, Universidade Federal de São Carlos, CP 676, 13560-970 São Carlos - SP, Brasil Recebido em 26/4/07; aceito em 16/7/07; publicado na web em 26/2/08

CONDUCTOMETRIC DETERMINATION OF CAPTOPRIL IN PHARMACEUTICAL FORMULATIONS USING COPPER(II) SULPHATE AS TITRANT. A simple and rapid conductometric method for captopril determination using copper(II) sulphate solution as titrant was developed. The method was based on the chemical reaction between captopril and Cu(II) ions yielding a precipitate. The conductance of the solution was monitored as a function of the added volume of titrant. The method was applied with success for captopril determination in three pharmaceutical formulations. The relative standard deviation for six successive measurements was smaller than 0.5%. Recovery values from three samples, ranging from 97.7 to 103%, were obtained. Keywords: captopril; conductometric titration; copper (II).

INTRODUÇÃO A hipertensão arterial é, atualmente, a doença cardiovascular mais comum, sendo a principal causa de acidente vascular cerebral, podendo conduzir a uma insuficiência cardíaca congestiva, aneurisma dissecante da aorta, infarto do miocárdio e hipertrofia ventricular esquerda1,2. Em função de sua alta