Voltammetric Studies and Determination of Levodopa and Carbidopa in Pharmaceutical Products

Quintino, Maria S. M.; Yamashita, Miyuki; Angnes, Lúcio

doi:10.1002/elan.200503445

Cited by 46 publications

(30 citation statements)

References 26 publications

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“…The voltammogram obtained for carbidopa (Figure 1 B) presented two irreversible oxidation waves with maximum currents registered at 677 mV and 1050 mV and a cathodic peak potential at 300 mV. This is an indicative of the presence of coupled chemical reactions as it was well discussed by Quintino et al 21 Zhang et al 17 attributes this second anodic peak to the oxidation of imine group of the carbidopa. L -1 perchloric acid solution using the MCPC with 20 %m/m PbO 2 .…”

Section: Cyclic Voltammetry Studiessupporting

confidence: 62%

“…As can be observed the same anodic and cathodic peaks were obtained, suggesting that the first anodic peak (677 mV) can be used for the determination of both compounds (L-dopa + carbidopa) and the second one at a potential of 1050 mV can be used for the determination of carbidopa. Figure 2 presents 21 using a glassy carbon electrode in the same supporting solution. Nevertheless, as can be seen from this figure, using the MCPE containing 20% m/m PbO 2 (10% m/m PbO 2 + 10% m/m polyester resin) there is an increase of peak current (anodic and/or cathodic).…”

Section: Cyclic Voltammetry Studiesmentioning

confidence: 99%

“…[16][17][18][19][20] To the best of our knowledge, there is only one differential pulse voltammetry (DPV) procedure in the literature using a glassy carbon electrode for the determination of L-dopa and a glassy carbon electrode coated with Nafion film for the determination of carbidopa. 21 DPV has been demonstrated to be a useful technique for the determination of many molecules of biological importance. 22 The high selectivity, sensitivity, accuracy, precision, simplicity and the possibility of analysis without tedious sample pre-treatment are the greatest advantage of this technique.…”

Section: Introductionmentioning

confidence: 99%

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Simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceuticals using a carbon paste electrode modified with lead dioxide immobilized in a polyester resin

Melo¹,

Seleghim²,

Polito³

et al. 2007

J. Braz. Chem. Soc.

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Um eletrodo de pasta de carbono modificado com dióxido de chumbo imobilizado em uma resina de poliéster foi desenvolvido para a determinação voltamétrica de pulso diferencial simultânea de L-dopa e carbidopa em formulações farmacêuticas. As curvas analíticas foram lineares em uma faixa de concentração de 2,6 × 10 -4 a 1,2 × 10 -3 mol L -1 e de 3,2 × 10 -5 a 1,5 × 10 -4 mol L -1 para L-dopa e carbidopa, respectivamente. Os limites de detecção foram 2,5 × 10 -5 mol L -1 e 3,7 × 10 -6 mol L -1 para L-dopa e carbidopa, respectivamente e as recuperações de L-dopa e carbidopa em duas amostras variaram de 98,1 a 103%. Os desvios padrão relativos foram menores que 2,5% para soluções 1,2 × 10 -4 e 1,2 × 10 -3 mol L -1 dessas catecolaminas e os resultados obtidos para L-dopa e carbidopa em formulações farmacêuticas usando o procedimento voltamétrico proposto estão em boa concordância com os valores rotulados ou com aqueles teores determinados empregando-se um procedimento enzimático a um nível de confiança de 95%.A carbon paste electrode modified with lead dioxide immobilized in a polyester resin has been developed for simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceutical formulations. The analytical curves were linear in the concentration ranges from 2.6 × 10 -4 to 1.2 × 10 -3 mol L -1 and from 3.2 × 10 -5 to 1.5 × 10 -4 mol L -1 for L-dopa and carbidopa, respectively. The detection limits were 2.5 × 10 -5 mol L -1 and 3.7 × 10 -6 mol L -1 for L-dopa and carbidopa, respectively and recoveries of L-dopa and carbidopa from two samples ranged from 98.1 to 103% of the added amount. The relative standard deviations were lower than 2.5% for 1.2 × 10 -4 and 1.2 × 10 -3 mol L -1 of these catecholamines solutions and the results obtained for L-dopa and carbidopa in pharmaceutical formulations using the proposed voltammetric procedure are in close agreement with the labeled values and/or those obtained using an enzymatic method at the 95% confidence level.Keywords: L-dopa, carbidopa, differential pulse voltammetry (DPV), carbon paste electrode modified with lead dioxide 3 On the other hand, catecholamines are present in relatively large amounts in pharmaceutical formulations and much effort has been devoted to the development of simple, rapid, accurate and precise analytical methods. Of those, the most employed methods include spectrophotometry, [4][5][6] high performance liquid chromatography (HPLC) with electrochemical detection [7][8][9][10][11][12][13][14][15] and capillary zone electrophoresis (CZE) with electrochemical detection. [16][17][18][19][20] To the best of our knowledge, there is only one differential pulse voltammetry (DPV) procedure in the literature using a glassy carbon electrode for the determination of L-dopa and a glassy carbon electrode coated with Nafion film for the determination of carbidopa. 21DPV has been demonstrated to be a useful technique for the determination of many molecules of biological importance. 22 The high selectivity, sensitivity, accuracy, pr...

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Section: Cyclic Voltammetry Studiessupporting

confidence: 62%

Section: Cyclic Voltammetry Studiesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceuticals using a carbon paste electrode modified with lead dioxide immobilized in a polyester resin

Melo¹,

Seleghim²,

Polito³

et al. 2007

J. Braz. Chem. Soc.

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“…Anodic peak potentials gave a linear dependence on pH with a negative slope of 63.5 mV/pH (correlation coefficient 0.996) and 63.2 mV/pH (correlation coefficient 0.997) for CD and BS, respectively, Figure 4. These slope values are close to the theoretical value of 59 mV/pH, obtained if the numbers of protons and electrons involved in the oxidation process are equal [6,26]. The relationship between pH and peak current of CD and BS was also investigated.…”

Section: Electrochemical Behaviour Of CD and Bs With Modifiedsupporting

confidence: 83%

Electroanalytical Characterisation of Dopa Decarboxylase Inhibitors Carbidopa and Benserazide on Multiwalled Carbon Nanotube and Poly(Nile blue A) Modified Glassy Carbon Electrodes

Kul

Brett

2011

International Journal of Electrochemistry

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Modified glassy carbon electrodes have been made by deposition of functionalised multiwalled carbon nanotubes (MWCNTs) followed by formation of poly(Nile blue) (PNB) films by electropolymerisation, using potential cycling in 0.1 M phosphate buffer solution (PBS) at pH 6.0. The electrochemical oxidation of carbidopa (CD) and benserazide (BS) on these MWCNTs/PNBmodified electrodes was investigated using cyclic and differential pulse voltammetry in 0.1 M PBS at different values of pH between 5.0 and 8.0; both CD and BS gave one diffusion-controlled irreversible oxidation peak in cyclic voltammetry. Analytical characterisation of CD and BS was carried out in 0.1 M PBS, pH 5.0. Peak currents in differential pulse voltammetry were linear over the concentration range of 1 × 10 −5 to 1 × 10 −4 M for CD and 4 × 10 −6 to 4 × 10 −5 M for BS. The repeatability, precision, and accuracy of the method were also investigated. Higher sensitivities and lower detection limits, of 1.17 µM for CD and 0.50 µM for BS, were obtained with this new modified electrode compared with previous studies reported in the literature.

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“…Compared to other choices, electrochemical methods provide useful alternatives that are faster, cheaper and highly sensitive. [6][7][8][9][10] Ascorbic acid (AA) is commonly known as vitamin-C. 11 AA plays an important role in several enzymatic reactions and in the defense against oxidative stress.…”

Section: Introductionmentioning

confidence: 99%

Poly-Dianix Blue/Multi-Walled Carbon Nanotube Modified Electrode for Detection of Levodopa in the Presence of High Concentrations of Ascorbic and Uric Acids

Hatefi-Mehrjardi¹,

Karimi²,

Barani³

et al. 2017

ACSi

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A selective and sensitive electrochemical sensor was studied for determination of levodopa (LD) in the presence of uric acid (UA) and ascorbic acid (AA) using poly-dianix blue and multi-walled carbon nanotubes (PDB/MWCNTs) modified glassy carbon electrode. Cyclic voltammetry, differential pulse voltammetry, and chronoamperometry methods were applied to investigate the electrocatalytic oxidation of LD, UA and AA in aqueous solutions. By DPV technique, LD, UA and AA give oxidation peaks at 0.380, 0.520 and 0.180 V, respectively. Under the optimized experimental conditions LD, UA and AA give a linear response in the range of 0.09-75 μmol L -1 , 0.3-110 μmol L -1 and 10-160 μmol L -1 , respectively. Accordingly, the obtained detection limits were 0.003, 0.002 and 0.023 μmol L -1 . The method provides a simple electrochemical sensor for successful determination of LD in human blood serum samples.

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Voltammetric Studies and Determination of Levodopa and Carbidopa in Pharmaceutical Products

Cited by 46 publications

References 26 publications

Simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceuticals using a carbon paste electrode modified with lead dioxide immobilized in a polyester resin

Simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceuticals using a carbon paste electrode modified with lead dioxide immobilized in a polyester resin

Electroanalytical Characterisation of Dopa Decarboxylase Inhibitors Carbidopa and Benserazide on Multiwalled Carbon Nanotube and Poly(Nile blue A) Modified Glassy Carbon Electrodes

Poly-Dianix Blue/Multi-Walled Carbon Nanotube Modified Electrode for Detection of Levodopa in the Presence of High Concentrations of Ascorbic and Uric Acids

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