Fast determination of naproxen in pharmaceutical formulations by batch injection analysis with pulsed amperometric detection

Abstract

Um método eletroanalítico original e rápido para a determinação de naproxeno em formulações farmacêuticas usando análise por injeção em batelada (BIA) com detecção amperométrica pulsada é descrito. Eletrodo de carbono vítreo foi usado como eletrodo de trabalho e solução tampão fosfato 0,05 mol L -1 como eletrólito suporte. O método amperométrico envolveu a aplicação contínua de dois pulsos de potencial ao eletrodo de trabalho com intuito de detectar naproxeno pela sua oxidação eletroquímica (+1,5 V por 200 ms) e de limpar a superfície do eletrodo de produtos de adsorção (+1,0 V por 100 ms), evitando contaminação do eletrodo. O método proposto possui várias vantagens para análises de rotina, incluindo: baixo desvio padrão relativo (3,0%, n = 10), elevada frequência analítica (90 h -1 ), exatidão satisfatória (baseado em determinações comparativas por espectrofluorimetria) e baixo limite de detecção (0,3 µmol L -1 ).A novel and fast electroanalytical method for naproxen determination in pharmaceutical formulations using batch injection analysis (BIA) with pulsed amperometric detection is described. Bare glassy carbon electrode was used as working electrode and 0.05 mol L -1 phosphate buffer solution as supporting electrolyte. The amperometric method involved the continuous application of two sequential potential pulses to the working electrode in order to detect naproxen by its electrochemical oxidation (+1.5 V for 200 ms) and to clean the electrode surface from adsorption products (+1.0 V for 100 ms), avoiding electrode contamination. The proposed method has several advantages for routine analysis, including: a low relative standard deviation between injections (3.0%, n = 10), high analytical frequency (90 h -1 ), satisfactory accuracy (based on comparative determinations by spectrofluorimetry) and low limit of detection (0.3 µmol L -1 ).Keywords: batch injection analysis, multiple-pulse amperometry, non-steroidal antiinflammatory drug IntroductionNaproxen, 2-(6-methoxynaphthalen-2-yl) propanoic acid, is a non-steroidal anti-inflammatory drug (NSAID) derived from propionic acid and has been widely used as an over-the-counter analgesic, anti-inflammatory and antipyretic agent. It is also commonly used for the reduction of stiffness caused by conditions including kidney stones, rheumatoid arthritis and other inflammatory rheumatic diseases. 1,2 NSAIDs have been associated with the increasing number of potentially cardiovascular events. However, a recent study classified naproxen as the least harmful NSAID in cardiovascular terms. 3 Different analytical methods have been proposed for the determination of naproxen in pharmaceutical formulations including spectrophotometry (UV region), 4,5 spectrofluorimetry, 6-8 capillary isotachophoresis 9 and high-performance liquid-chromatography (HPLC) coupled with spectrophotometric, 10 amperometric 11 and mass spectrometric detectors. 1 Nevertheless, these analytical methods require expensive equipment and reagents, are time-consuming and often necessitate laborious pre-and pos...

Determinação rápida e simples de citrato de sildenafila (Viagra® e genéricos) empregando eletrodo impresso de carbono em sistemas FIA e BIA com detecção amperométrica

“…37 De modo alternativo, células eletroquímicas hidrodinâ-micas para SPE de custo muito menor podem ser confeccionadas em laboratório com o uso de microrretífica, 38 tornearia 35 ou impressão 3D. 39 Apesar da praticidade e rapidez destes sistemas hidrodinâmicos com SPE, existem poucos trabalhos na literatura para determinação de fármacos em medicamentos por FIA-SPE [40][41][42][43] e BIA-SPE. 43 Dessa forma, este trabalho propõe a determinação de CS empregando SPE em sistemas BIA e FIA com detecção amperométrica, sendo avaliados cinco SPE de diferentes eletrodos de trabalho.…”

Conductometric determination of naproxen in bulk and pharmaceutical dosage form

“…It also inhibits the enzyme thromboxane synthase causing inhibition of the platelet aggregation process [4]. Naproxen is determined in bulk and pharmaceutical dosage forms by UV spectrophotometric techniques [5,6], TLC [7], HPLC with UV detection methods [8], GC-MS [9], ionselective methods [10], phosphorescence and chemiluminescence methods [11], spectrofluorimetric techniques [12][13][14] and capillary electrophoresis with mass detectors [15][16][17]. Bio-analytical methods for detection of naproxen and its metabolites have also been reported [8].…”

Supramolecular Approach to Decorate Multi-Walled Carbon Nanotubes with Negatively Charged Iron(II) Complexes

“…13 To overcome this drawback, some groups explored noncovalent functionalization through van der Waals forces with pyrene derivatives, [14][15][16] surfactants, 17 and also with standard Werner-type complexes. 18 After functionalization (of both kinds), the material can be processed as a dispersion in some common solvent, which allows its application for different purposes, as production of printed electrodes 19 and phenolic resin nanocomposite, 17 for example. The association of CNTs with polymers provides films with enhanced electrical conductivity and superior mechanical performance provided that hydrophobic polymer chains can overcome van der Waals interactions that sustain CNTs together in bundles.…”