Determination of pKa of felodipine using UV–Visible spectroscopy

Pandey, Murali Monohar; Jaipal, A.; Kumar, Amit; Malik, Rohan; Charde, Shrikant Y.

doi:10.1016/j.saa.2013.07.001

Cited by 40 publications

(18 citation statements)

References 21 publications

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“…It can be clearly seen from the loading plot (the left bottom corner) that the column performances for felodipine are not very much affected by the pH of aqueous mobile phase, since variables at both pH are close to each other, which suggests that the analytes are in a neutral state at both pH3 and 7.4, and the column performance is not affected by pH change of the aqueous mobile phase. The reported p K a value of felodipine is 5.07 , which is close to the value found in the DrugBank. Felodipine should be positively charged at pH 3 accordingly.…”

Section: Resultssupporting

confidence: 83%

“…2A, it was seen that Poroshell EC-C 18 2.7 m columns show the best batch-to-batch reproducibility with all three columns very close to each other, followed by Cortecs C 18 , 1.6 m and Kinetex C 18 2.6 m, Cortecs C 18+ 2.7 m, Cortecs C 18+ 1.6 m, Cortecs C 18 2.7 m and Poroshell HPH C 18 , 2.7 m. It can be clearly seen from the loading plot (the left bottom corner) that the column performances for felodipine are not very much affected by the pH of aqueous mobile phase, since variables at both pH are close to each other, which suggests that the analytes are in a neutral state at both pH3 and 7.4, and the column performance is not affected by pH change of the aqueous mobile phase. The reported pK a value of felodipine is 5.07 [33], which is close to the value found in the DrugBank. Felodipine should be positively charged at pH 3 accordingly.…”

Section: Isocratic Elutionsupporting

confidence: 83%

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Core–shell column Tanaka characterization and additional tests using active pharmaceutical ingredients

Ludvigsson

Kjellberg

2016

J of Separation Science

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In the last decade, core-shell particles have gained more and more attention in fast liquid chromatography separations due to their comparable performance with fully porous sub-2 μm particles and their significantly lower back pressure. Core-shell particles are made of a solid core surrounded by a shell of classic fully porous material. To embrace the developed core-shell column market and use these columns in pharmaceutical analytical applications, 17 core-shell C columns purchased from various vendors with various dimensions (50 mm × 2.1 mm to 100 mm × 3 mm) and particle sizes (1.6-2.7 μm) were characterized using Tanaka test protocols. Furthermore, four selected active pharmaceutical ingredients were chosen as test probes to investigate the batch to batch reproducibility for core-shell columns of particle size 2.6-2.7 μm, with dimension of 100 × 3 mm and columns of particle size 1.6 μm, with dimension 100 × 2.1 mm under isocratic elution. Columns of particle size 2.6-2.7 μm were also tested under gradient elution conditions. To confirm the claimed comparable efficiency of 2.6 μm core-shell particles as sub-2 μm fully porous particles, column performances of the selected core-shell columns were compared with BEH C , 1.7 μm, a fully porous column material as well.

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Section: Resultssupporting

confidence: 83%

Section: Isocratic Elutionsupporting

confidence: 83%

Core–shell column Tanaka characterization and additional tests using active pharmaceutical ingredients

Ludvigsson

Kjellberg

2016

J of Separation Science

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“…We measured p K a values for anilines 1 – 8 in aqueous solutions (with 4% methanol) employing an established UV–vis spectroscopy-based method ( Table 1 ). 11 The observed p K a values were then plotted against the Hammett σ values (2σ para , because there are two flanking aromatic rings adjacent to the pivotal aniline ring, each having one substituent at the para position). As shown in Figure 2 , it is evident that there is a clear linear correlation ( R 2 > 0.92) between the acidity constants of para -substituted 2,6-diarylanilines 1 – 6 and the Hammett σ values.…”

Section: Resultsmentioning

confidence: 99%

Stabilization of 2,6-Diarylanilinum Cation by Through-Space Cation−π Interactions

Padial¹,

Poater

Nguyen³

et al. 2017

J. Org. Chem.

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Energetically favorable cation−π interactions play important roles in numerous molecular recognition processes in chemistry and biology. Herein, we present synergistic experimental and computational physical–organic chemistry studies on 2,6-diarylanilines that contain flanking meta/para-substituted aromatic rings adjacent to the central anilinium ion. A combination of measurements of pKa values, structural analyses of 2,6-diarylanilinium cations, and quantum chemical analyses based on the quantitative molecular orbital theory and a canonical energy decomposition analysis (EDA) scheme reveal that through-space cation−π interactions essentially contribute to observed trends in proton affinities and pKa values of 2,6-diarylanilines.

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“…Using this method, the pKa's of Felodipine: 5.07 at IoStr 0.02M. 12 Resperidone: 8.62, IoStr 0.02M 13 and Brimonidine Tartrate: 7.22, at 25°C IoStr 0.3M 14 were determined using this equation. This method of pKa calculation was compared to linear regression in two different studies, which both resulted in a similar pKa value.…”

Section: Albert and Serjeant Methodsmentioning

confidence: 99%

Recent Advancements in Spectrophotometric pKa Determinations: A Review

Berkhout

2019

IJPER

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The pKa value is a key feature in Absorption, Distribution, Metabolism and Excretion (ADME) of drugs, thus knowing this value is critical in drug development. In this review, pKa values determined in the past decade, using UV-Vis spectrometry, are discussed. To determine the pKa, four methods were applied; Henderson-Hasselbach, Albert-Serjeant, Bates-Schwarzenbach and Spectrometric titrations. This review will show the value of this aged but well-established technique in the past decade, due to its simplicity, accuracy, cost efficiency and reproducibility.

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Determination of pKa of felodipine using UV–Visible spectroscopy

Cited by 40 publications

References 21 publications

Core–shell column Tanaka characterization and additional tests using active pharmaceutical ingredients

Core–shell column Tanaka characterization and additional tests using active pharmaceutical ingredients

Stabilization of 2,6-Diarylanilinum Cation by Through-Space Cation−π Interactions

Recent Advancements in Spectrophotometric pKa Determinations: A Review

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