3. pKa Determination

  1. Alex Avdeef1,2

Published Online: 7 MAY 2012

DOI: 10.1002/9781118286067.ch3

Absorption and Drug Development: Solubility, Permeability, and Charge State, Second Edition

Absorption and Drug Development: Solubility, Permeability, and Charge State, Second Edition

How to Cite

Avdeef, A. (2012) pKa Determination, in Absorption and Drug Development: Solubility, Permeability, and Charge State, Second Edition, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9781118286067.ch3

Author Information

  1. 1

    Cambridge, Massachusetts, USA

  2. 2

    Boston, Massachusetts, USA

Publication History

  1. Published Online: 7 MAY 2012
  2. Published Print: 11 MAY 2012

ISBN Information

Print ISBN: 9781118057452

Online ISBN: 9781118286067

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Keywords:

  • ionization constant pKa determination by potentiometric technique;
  • ionic strength and temperature impact;
  • charge state and the pKa, affecting drug absorption;
  • constant ionic medium activity scale;
  • molality to molarity conversion

Summary

This chapter contains sections titled:

  • Charge State and the pKa

  • Methods of Choice for the Determination of the pKa

  • Titration with a Glass-Membrane pH Electrode

  • Equilibrium Equations and the Ionization Constant

  • “Pure Solvent” Activity Scale

  • Ionic Strength and Debye–Hückel/Davies Equation

  • “Constant Ionic Medium” Activity Scale

  • Temperature Dependence of pKa Values

  • Electrode Calibration and Standardization

  • Bjerrum Plot: Most Useful Graphical Tool in pKa Analysis

  • Cosolvent Methods for pKa Determination of Practically Insoluble Substances

  • Other Methods for pKa Measurement

  • pKa Microconstants

  • pKa Compilations

  • pKa Prediction Programs

  • Database of pKa (25°C and 37°C)

  • Quick Start: Determination of the pKa of Codeine

  • Tutorial for Measurements with Glass-Membrane pH Electrode

  • pH Convention Adopted by IUPAC and Supported by NIST

  • Liquid-Junction Potentials (LJP)

  • pKa Refinement by Weighted Nonlinear Regression

  • Molality to Molarity Conversion

  • References