Determinação eletroanalítica de Losartana®, Captopril® e Alisquireno® em fluidos biológicos e em formulações comerciais

Abstract

Blood pressure (BP) change is an important risk factor for cardiovascular and renal complications. The renin-angiotensin-aldosterone system (RAAS) has been the target in the center of phase for all the cardiovascular and cardio-renal complications. In this sense, Losartan®, Captopril® and Aliskiren® are drugs in the class of angiotensin receptor (ARBs). Thus, this thesis aims to present methods of analysis grounded in electrochemical techniques by square wave voltammetry (SWV) in order to facilitate and financially viable analysis of the drugs in question. The electrochemical signals were obtained by electrochemical oxidation of drugs in diamond electrode doped with boron (BDD). Analyses were made of electrolytic means of Britton-Robinson buffer (BR) in different pH's where we fixed the best analysis parameters (frequency, amplitude and scan increment). Since the square wave optimized parameters, the linear region was defined between peak current (Ip) vs. concentration. Oxidation of drugs show well defined and irreversible oxidation peaks. For Aliskiren®, the calibration curve is obtained in the concentration range of 1.81 x 10-5 to 1.63 x 10-4 mol/L (r = 0.997), with limits of detection and quantification of 2.5 x 10-8 and 8.4 x 10-8 mol/L, respectively. The recovery values reaching 98.2% to 100.2%. For Losartan®, the calibration curve is obtained in the concentration range of 9.38 x 10-6 to 8.75 x 10-5 mol/L (r = 0.997), with limits of detection and quantification of 2.64 x 10-8 and 8.82 x 10-8 mol/L, respectively. The recovery values reaching 96.2 % to 113.5 %. And finally for Captopril®, the calibration curve is obtained in the concentration range of 2.70 x 10-5 to 2.30 x 10-4 mol/L ( r = 0.995 ) , with limits of detection and quantification of 6.67 x 10-8 and 2.22 x 10-7 mol/L, respectively. The recovery values reaching 99.7 % to 101.0 %. These results indicate that there is no interference effects of the array of drugs on the analytical determination of the same. In Aliskiren® analysis and Captopril® interferents in human plasma serum is common insignificantly altered the analysis, yielding good average recovery of 95.5 % to 97.8 % for Aliskiren® and 100.6 % for Captopril®. It can also say that the BDD electrode showed a stable response, which is considered selective and sensitive to the drugs studied.