The acid-base equilibria of rupatadine fumarate were investigated in the absence and the presence of differently charged anionic (sodium dodecyl sulfate), cationic (cetyltrimethylammonium bromide), and nonionic (4-octylphenol polyethoxylate) surfactants. The pK(a) values of rupatadine and fumaric acid were potentiometrically determined at 25 degrees C and at a constant ionic strength (0.1 M NaCl). The obtained potentiometric data were evaluated with use of the computer program Hyperquad. Ionization in the surfactant-free media was defined, and the effects of surfactants on protolytic equilibria of rupatadine were estimated, based on a shift of the apparent ionization constants determined in micellar solutions against the pK(a) values in water. The anionic SDS micelles caused an increase in the pK(a) values of all the rupatadine ionization centers (Delta pK(a) up to +1.44), while the shift of protolytic equilibria in different directions was observed in the case of the cationic CTAB (De...lta pK(a) from -1.99 to +0.14) and the nonionic TX -100 (Delta pK(a) from -0.72 to +0.38) micelles. Distribution diagrams of the equilibrium forms as a function of pH indicate that the change in distribution is most strongly expressed in the pH range 4-8 which includes biopharmaceutically important pH values.
Source:
Journal of Chemical and Engineering Data, 2018, 63, 8, 3150-3156
TY - JOUR
AU - Popović-Nikolić, Marija
AU - Popović, Gordana
AU - Stojilković, Kristina
AU - Dobrosavljević, Maja
AU - Agbaba, Danica
PY - 2018
UR - http://farfar.pharmacy.bg.ac.rs/handle/123456789/3065
AB - The acid-base equilibria of rupatadine fumarate were investigated in the absence and the presence of differently charged anionic (sodium dodecyl sulfate), cationic (cetyltrimethylammonium bromide), and nonionic (4-octylphenol polyethoxylate) surfactants. The pK(a) values of rupatadine and fumaric acid were potentiometrically determined at 25 degrees C and at a constant ionic strength (0.1 M NaCl). The obtained potentiometric data were evaluated with use of the computer program Hyperquad. Ionization in the surfactant-free media was defined, and the effects of surfactants on protolytic equilibria of rupatadine were estimated, based on a shift of the apparent ionization constants determined in micellar solutions against the pK(a) values in water. The anionic SDS micelles caused an increase in the pK(a) values of all the rupatadine ionization centers (Delta pK(a) up to +1.44), while the shift of protolytic equilibria in different directions was observed in the case of the cationic CTAB (Delta pK(a) from -1.99 to +0.14) and the nonionic TX -100 (Delta pK(a) from -0.72 to +0.38) micelles. Distribution diagrams of the equilibrium forms as a function of pH indicate that the change in distribution is most strongly expressed in the pH range 4-8 which includes biopharmaceutically important pH values.
PB - Amer Chemical Soc, Washington
T2 - Journal of Chemical and Engineering Data
T1 - Acid-Base Equilibria of Rupatadine Fumarate in Aqueous Media
VL - 63
IS - 8
SP - 3150
EP - 3156
DO - 10.1021/acs.jced.8b00422
UR - conv_4192
ER -
@article{
author = "Popović-Nikolić, Marija and Popović, Gordana and Stojilković, Kristina and Dobrosavljević, Maja and Agbaba, Danica",
year = "2018",
abstract = "The acid-base equilibria of rupatadine fumarate were investigated in the absence and the presence of differently charged anionic (sodium dodecyl sulfate), cationic (cetyltrimethylammonium bromide), and nonionic (4-octylphenol polyethoxylate) surfactants. The pK(a) values of rupatadine and fumaric acid were potentiometrically determined at 25 degrees C and at a constant ionic strength (0.1 M NaCl). The obtained potentiometric data were evaluated with use of the computer program Hyperquad. Ionization in the surfactant-free media was defined, and the effects of surfactants on protolytic equilibria of rupatadine were estimated, based on a shift of the apparent ionization constants determined in micellar solutions against the pK(a) values in water. The anionic SDS micelles caused an increase in the pK(a) values of all the rupatadine ionization centers (Delta pK(a) up to +1.44), while the shift of protolytic equilibria in different directions was observed in the case of the cationic CTAB (Delta pK(a) from -1.99 to +0.14) and the nonionic TX -100 (Delta pK(a) from -0.72 to +0.38) micelles. Distribution diagrams of the equilibrium forms as a function of pH indicate that the change in distribution is most strongly expressed in the pH range 4-8 which includes biopharmaceutically important pH values.",
publisher = "Amer Chemical Soc, Washington",
journal = "Journal of Chemical and Engineering Data",
title = "Acid-Base Equilibria of Rupatadine Fumarate in Aqueous Media",
volume = "63",
number = "8",
pages = "3150-3156",
doi = "10.1021/acs.jced.8b00422",
url = "conv_4192"
}
Popović-Nikolić, M., Popović, G., Stojilković, K., Dobrosavljević, M.,& Agbaba, D.. (2018). Acid-Base Equilibria of Rupatadine Fumarate in Aqueous Media. in Journal of Chemical and Engineering Data
Amer Chemical Soc, Washington., 63(8), 3150-3156.
https://doi.org/10.1021/acs.jced.8b00422
conv_4192
Popović-Nikolić M, Popović G, Stojilković K, Dobrosavljević M, Agbaba D. Acid-Base Equilibria of Rupatadine Fumarate in Aqueous Media. in Journal of Chemical and Engineering Data. 2018;63(8):3150-3156.
doi:10.1021/acs.jced.8b00422
conv_4192 .
Popović-Nikolić, Marija, Popović, Gordana, Stojilković, Kristina, Dobrosavljević, Maja, Agbaba, Danica, "Acid-Base Equilibria of Rupatadine Fumarate in Aqueous Media" in Journal of Chemical and Engineering Data, 63, no. 8 (2018):3150-3156,
https://doi.org/10.1021/acs.jced.8b00422 .,
conv_4192 .
