[Study of local anaesthetics: Part 206* Micellization of selected of quaternary ammonium salt derived from heptacaine].

Micellization of selected quaternary ammonium compounds derived from heptacaine have been studied by absorption spectroscopy in the UV/VIS spectral region with the use of a pyrene probe. The compounds studied in the aqueous solution have been marked as H22, H26, H27, H29, H34, H + Al and H + B and the derivative marked as H34 was studied in a 3 mol/l ethanol solution at the temperature of 25 °C. In the homologous series of the studied bromides H22, H26, H27 and H29, cmc was observed to be dependent on the number of carbon atoms nc in the hydrophobic chain: ln (cmc) = -3.131-0.421nC. The Free Gibbs energy necessary for the transfer of a methyl group of the alkyl chain from the water phase to the inner part of the micelle at the temperature of 25 °C is (-0.421 ± 0.034)RT.