Micellization of 1-Methoxy-3-(4-methylpiperazin-1-yl)propan-2-yl-4-propyl-oxyphenyl Carbamate in Aqueous Solution

Abstract

Specific conductivities of local anaesthetic 1-methoxy-3-(4-methylpiperazin-1-yl)propan-2-yl-4-propyl-oxyphenyl carbamate (LM₉) in aqueous solution were measured as a function of the concentration and temperature. The critical micelle concentration, CMC, degree of ionization and the counterion binding of the micelle were estimated from the dependence of the specific conductivity measurements at various temperatures. The dependence of CMC on temperature was shown to be U-shaped with a minimum at the temperature T = 298.15 K. Thermodynamic parameters (Gibbs energy ΔG°, enthalpy ΔH°, entropy ΔS°) for the micelle system were estimated by applying the mass action model. Molecule LM₉ exhibited the enthalpy-entropy compensation phenomenon. The compensation temperature T_c of the studied compound was 301.79 K.