Mixed micellization analysis of tri-substituted SAIL and amphiphilic drug mixture in aqueous/salt media at diverse temperatures

Abstract

Abstract The present work aimed to study the mixed micellar behaviour of a tri-substituted imidazolium based surface-active ionic liquid (SAIL), 1-tetradecyl-2,3-dimethylimidazolium bromide [C14bmim][Br], with a drug Nortriptyline hydrochloride (NOT) in the water/salt (Na2SO4) medium using surface tension measurements (298.15 K) alongwith conductivity measurements (298.15K–313.15K). Lower experimentally obtained cmc values compared to their ideal values suggest that the investigated amphiphiles interact strongly. The values of micellar mole fraction (X 1) based on the several proposed models (Rubingh, Motomura, and Rodenas) and the ideal micellar mole fraction (X id ) were assessed, and the predicted outcomes indicate that NOT has a significant contribution to the formation of mixed micelles, which increases as the [C14bmim][Br] mole fraction is increased. The negative values of micellization’s Gibbs free energy (ΔGm 0) between the examined amphiphiles were an indication of spontaneous mixed micelle formation. Micellar changes in entropy (ΔSm 0) and enthalpy (ΔHm 0) were also computed and discussed. Using surface tension measurements, surface-active parameters like surface tension at cmc (γ cmc ), minimum surface area per IL molecule (A min), maximum surface excess concentration (τ max), effectiveness of surface tension reduction (π cmc ), and cmc of mixed system have been estimated. The results showed an improved adsorption and micellization properties of these mixtures which will surely contribute to the tremendous rise of these mixed systems in drug delivery applications.