Comparison between capillary electrophoresis, liquid chromatography, potentiometric and spectrophotometric techniques for evaluation of pKa values of zwitterionic drugs in acetonitrile–water mixtures

Barbosa, J.; Barrón, D.; Jiménez-Lozano, E; Sanz‐Nebot, Victoria

doi:10.1016/s0003-2670(01)00997-7

Cited by 110 publications

(88 citation statements)

References 46 publications

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“…(3a) that was reported as pKa1 6.09 and pKa 2 8.62 [44]. However the second intersection point of curve could not be observed because of after pH 8.00 the peak was disappeared.…”

Section: Resultsmentioning

confidence: 94%

Anodic Voltammetry of Ciprofloxacin and its Analytical Applications

Uslu

Bozal²,

Kuscu³

2010

TOCBMJ

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Abstract:The electrooxidative behavior and determination of ciprofloxacin at a glassy carbon electrode were investigated using cyclic, linear sweep, differential pulse and square wave voltammetric techniques. The dependence of the peak current and peak potentials on pH, concentration, nature of buffer, and scan rate were examined. The oxidation of ciprofloxacin gave a single and irreversible peak at glassy carbon electrode. The process was diffusion controlled. A linear response was obtained between 1.0 10 -6 and 4.0 10 -5 M in 0.1 M sulphuric acid for both techniques. The recovery studies were also achieved to check selectivity and accuracy of the methods. The proposed methods were applied for the determination of ciprofloxacin from pharmaceutical dosage forms without any time-consuming extraction, separation, adsorption steps. The repeatability, reproducibility, precision and accuracy of the proposed methods were investigated.

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“…(3a) that was reported as pKa1 6.09 and pKa 2 8.62 [44]. However the second intersection point of curve could not be observed because of after pH 8.00 the peak was disappeared.…”

Section: Resultsmentioning

confidence: 94%

Anodic Voltammetry of Ciprofloxacin and its Analytical Applications

Uslu

Bozal²,

Kuscu³

2010

TOCBMJ

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“…The acid content of the SRS DNAPL is higher than others reported for crude oil, creosote or coal tar, possibly indicating that organic or inorganic acids co-disposed at the SRS M-area lagoon partitioned into the DNAPL. The strength of the acid can be estimated based on the electrophoretic mobility of the sample [Barbosa, 2001]. The pK a determination is based on the principle that a solute exhibits a maximum electrophoretic mobility when it is fully ionized, a minimum electrophoretic mobility when it is fully protonated and an intermediate mobility in the regions surrounding its pK a [Perez-Urquiza and Beltran, 2001].…”

Section: Aciditymentioning

confidence: 99%

DOE-EMSP Final Report: Characterization of Changes in Colloid and DNAPL Affecting Surface Chemistry and Remediation

Powers¹,

Grimberg²,

Denham³

2007

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“…It is well-known that pK a values are important for the development of new compounds with biological activity. It can be due to the relationships between the pK a values and those structures, which may help studies in drugs design and also explain the biopharmaceutical properties of substances (Duran, Aydemir, 2012;Barbosa et al, 2001). There are several experimental methods for determining the acidity constants in aqueous solutions for example, conductometry, spectrophotometric, capillary electrophoresis, calorimetric adsorption, potentiometric titration, HPLC, solubility, partition and distribution (Reijenga et al, 2013;Heinze, 1984;Thurlkill et al, 2005;Santos et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Theoretically nanoscale study on ionization of muscimol nano drug in aqueous solution

Kiani

Abbaszadeh

Pousti

et al. 2015

Braz. J. Pharm. Sci.

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In the present work, acid dissociation constant (pK a ) values of muscimol derivatives were calculated using the Density Functional Theory (DFT) method. In this regard, free energy values of neutral, protonated and deprotonated species of muscimol were calculated in water at the B3LYP/6-31G(d) basis sets. The hydrogen bond formation of all species had been analyzed using the Tomasi's method. It was revealed that the theoretically calculated pK a values were in a good agreement with the existing experimental pK a values, which were determined from capillary electrophoresis, potentiometric titration and UV-visible spectrophotometric measurements.Uniterms: Nanodrug. Muscimol. Acid/dissociation constants. Computational chemistry. Density Functional Theory.No presente trabalho, calculou-se a constante de dissociação do ácido (pK a ) dos derivados de muscimol, utilizando-se o método da teoria do funcional de densidade (DFT). Com esse objetivo, calcularam-se os valores das espécies neutra, protonada e desprotonada do muscimol em água em base B3LYP/6-31G(d). A formação da ligação de hidrogênio de todas as espécies foi analisada utilizando o método de Tomasi. Demonstrou-se que os valores de pKa calculados teoricamente estavam em boa concordância com os valores experimentais disponíveis, determinados por eletroforese capilar, titulação potenciométrica e medidas por espectrofotometria UV-visível.Unitermos: Nanofármaco. Muscimol. Ácido/constantes de dissociação. Química computacional. Teoria do funcional de densidade.

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Comparison between capillary electrophoresis, liquid chromatography, potentiometric and spectrophotometric techniques for evaluation of pKa values of zwitterionic drugs in acetonitrile–water mixtures

Cited by 110 publications

References 46 publications

Anodic Voltammetry of Ciprofloxacin and its Analytical Applications

Anodic Voltammetry of Ciprofloxacin and its Analytical Applications

DOE-EMSP Final Report: Characterization of Changes in Colloid and DNAPL Affecting Surface Chemistry and Remediation

Theoretically nanoscale study on ionization of muscimol nano drug in aqueous solution

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