A series of substituted pyridinecarboxylic acids and their N-oxides has been synthesized, their dissociation constants and electrophoretic mobility have been measured, and their pharmacological action has been studied. The presence of a satisfactory correlation between the pKa of of 4-substituted pyridinecarboxylic acids or their oxides and the σpelectronegativity constants of the substituents has been shown. A linear dependence between dissociation constants and electrophoretic mobility of pyridinecarboxylic acids or their N-oxides has been found in various buffer solutions. The pharmacological action of a number of the synthesized compounds has been studied