Development of analytical strategies for the determination of the anti-hypertensive furosemide

Author(s)

Felipe Silva Semaan

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT)
• Defense date: 2007-10-19

Examining board members

Eder Tadeu Gomes Cavalheiro; Lazaro Moscardini D\'Assuncao; Fernando Mauro Lancas; Helena Redigolo Pezza; Boaventura Freire dos Reis

• Advisor: Eder Tadeu Gomes Cavalheiro

Abstract

The development and application of different procedures for the quantification of the drug furosemide, exploiting its reactions and physical properties are described. The presented methods were based in static and flow injection procedures. Among the static redox procedures titrimetry was applied, which exploited the hydrolysis and oxidation reactions of this drug; batch spectrophotometric determination was carried out applying the complexation between furosemide and ferric ions and, electroanalytical determinations, by cyclic, differential pulse and square wave voltammetry, were developed exploiting the electrochemical behavior of the analyte. All the static procedures were used as base to the development of flow injection methods, aiming to minimize the manipulation of standards and samples, as well as to reduce the reagent and solutions consumes and the waste generation, and to improve the analytical frequency. Based on the flow injection procedures some experiments were developed using spectrophotometric detectors, applying redox and complexation reactions; fluorimetric detectors, based on the fluorescence emission generated by the analyte when excited and exploiting its improvement by micellar media; and electrochemical detectors, based on the hydrolysis and oxidation under suitable conditions. Lost of sensitivity could be observed in the flow injection procedures, on the other hand, improvement on analytical frequency, reduction on operational costs and minimization on solutions handling could also be noted. The waste generated was reused in the majority of the cases. All the procedures described were applied to commercial samples and/or synthetic biological material, with satisfactory results when statistically compared to those obtained by a reference method to the same samples. Recovery tests also demonstrated the applicability of the developed strategies. Interference from the constituents of the pharmaceutical formulations was not observed. (AU)

• FAPESP's process: 04/08550-0 - Development of strategies for the determination of the anti-hypertensive furosemide
• Grantee: Felipe Silva Semaan
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)