Thermodynamic Solution Properties of Benzalkonium Chloride in Aqueous and Ethanolic Media and its Interactions with Organized Assemblies of Anionic Surfactant Sodium Dodecyl Sulphate and Amino Acids

Abstract

AbstractThis manuscript reports the physicochemical behaviour of antimicrobial cationic surfactant benzalkonium chloride (BAC) as well as its interaction with the anionic surfactant sodium dodecyl sulfate in term of mixed micelle. Surface activity of pure BAC was studied by measuring the surface parameters i. e. surface pressure (Π), surface excess concentration (Γ), area per molecule and standard Gibbs free energy of adsorption (ΔGads). The electrical conductivity was measured to calculate the thermodynamic parameters like free energy of micellization, ΔGm, enthalpy of micellization, ΔHm and entropy of micellization, ΔSm. The interaction of the drug with sodium dodecyl sulfate was studied, in term of mixed micelle, by electrical conductivity and UV/Visible spectroscopy. Spectroscopic method helps to calculate the partition coefficient (Kx) and free energy of partition, while the conductivity method is helpful to calculate thermodynamic parameters of their interaction. The effect of different amino acids on CMC of BAC has also been studied.