AbstractThe thermodynamic pKa* values of 3‐substituted 3‐(4‐biphenylyl)‐3‐hydroxypropionic acids1a‐‐swere determined potentiometrically in DMSO/water (80:20). The mixed solvent was selected for chemical and pharmacological reasons. The results are discussed in terms of substituent effects and solute‐solvent interactions. The estimated pKa values in water are in the range of 3‐‐4, in accordance with data reported in the literature for similar nonsteroidal anti