QUANTITATIVE RETENTION-STRUCTURE AND RETENTION-ACTIVITY RELATIONSHIP STUDIES OF LOCAL-ANESTHETICS BY MICELLAR LIQUID-CHROMATOGRAPHY

The retention of compounds in micellar liquid chromatography (MLC) is governed by hydrophobic and electrostatic forces, For ionic compounds, both interactions should be considered. The present report offers a n ovel retention model that includes the hydrophobicity of compounds and the molar fraction of the charged form of compounds and compares it w ith other previously reported models. High correlations between the lo garithm of capacity factors and these structural parameters were obtai ned or local anesthetics with different degrees of ionization using a nonionic surfactant solution as mobile phase, Modeling the retention o f compounds as a function of physicochemical parameters and experiment al variables is established by means of multiple linear regression. In addition, a predictive model for estimating the hydrophobicity of loc al anesthetics is proposed. Finally, quantitative and qualitative rete ntion-activity relationships in MLC are also investigated for these co mpounds. An excellent correlation between the capacity factors in MLC and the anesthetic potency of local anesthetics was obtained.