Ionization constants and water solubilities of some aminoalkylphenothiazine tranquillizers and related compounds

Abstract

Abstract A simple graphical method is described for deriving the ionization constants of poorly soluble organic bases from the pH dependence of the water solubility. Ionization constants and water solubilities of 13 aminoalkylphenothiazines and related drugs have been determined using this procedure. Potent tranquillizing activity in this group of compounds is shown to be associated with a low water solubility at blood pH.