Method of UV-Metric and pH-Metric Determination of Dissociation Constants of Ionizable Drugs: Valsartan
The result's identifiers
Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F19%3A39914750" target="_blank" >RIV/00216275:25310/19:39914750 - isvavai.cz</a>
Result on the web
<a href="https://link.springer.com/article/10.1007%2Fs10953-019-00913-y" target="_blank" >https://link.springer.com/article/10.1007%2Fs10953-019-00913-y</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1007/s10953-019-00913-y" target="_blank" >10.1007/s10953-019-00913-y</a>
Alternative languages
Result language
angličtina
Original language name
Method of UV-Metric and pH-Metric Determination of Dissociation Constants of Ionizable Drugs: Valsartan
Original language description
Valsartan is used for treating high blood pressure, congestive heart failure and to increase the chances of living longer after a heart attack and to reduce the mortality rate for people with left ventricular dysfunction following a heart attack. Regression analysis of the pH-spectra with REACTLAB and of the pH-titration curve with ESAB determined two close consecutive dissociation constants. MARVIN and ACD/Percepta predicted two protonation sites. In water a soluble anion L2- forms two sparingly soluble species LH-, LH2. Although adjusted pH less affected the spectral changes in the chromophore, pK(a1)(T) = 3.70 +/- 0.12, pK(a2)(T) = 4.82 +/- 0.08 at 25 degrees C and pK(a1)(T) = 3.44 +/- 0.08, pK(a2)(T) = 4.67 +/- 0.02 at 37 degrees C in an aqueous phosphate buffer were determined. By regression analysis of potentiometric pH-titration curves and pK(a1)(T)= 3.51 +/- 0.01, pK(a2)(T) = 4.63 +/- 0.01, at 25 degrees C and pKT(a1) = 3.44 +/- 0.03, pK(a2)(T) = 4.51 +/- 0.03 at 37 degrees C in an aqueous medium were estimated. Positive enthalpy values Delta H-0(pK(a1)) = 10.33 kJ.mol(-1), Delta H-0(pK(a2)) = 17.70 kJ.mol(-1) showed that the dissociation process was endothermic. The standard state Gibbs energy changes are Delta G(0)(pK(a1)) = 20.03 kJ.mol(-1), Delta G(0)(pK(a2)) = 26.43 kJ.mol(-1) at 25 degrees C and the Delta S-0 at 25 degrees C and 37 degrees C are (Delta S-0(pK(a1)) = - 32.56 J.K-1.mol(-1), Delta S-0(pK(a2)) = - 29.26 J.K-1.mol(-1) at 25 degrees C and Delta S-0(pK(a1)) = - 30.01 J.K-1.mol(-1), Delta S-0(pK(a2)) = - 25.92 J.K-1.mol(-1) at 37 degrees C. [GRAPHICS] .
Czech name
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Czech description
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Classification
Type
J<sub>imp</sub> - Article in a specialist periodical, which is included in the Web of Science database
CEP classification
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OECD FORD branch
10406 - Analytical chemistry
Result continuities
Project
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Continuities
I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace
Others
Publication year
2019
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Data specific for result type
Name of the periodical
Journal of Solution Chemistry
ISSN
0095-9782
e-ISSN
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Volume of the periodical
48
Issue of the periodical within the volume
8-9
Country of publishing house
DE - GERMANY
Number of pages
21
Pages from-to
1266-1286
UT code for WoS article
000489791300006
EID of the result in the Scopus database
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