Abstract
Mixtures of an antidepressant drug, amitriptyline hydrochloride (AMT), and ionic liquid, 1-hexadecyl-3-methylimidazolium chloride (HMICl), were investigated by tensiometry at a temperature of 298.15 K with diverse mole fraction (a1) of HMICl to determine the association, surface, and thermodynamic properties. Fourier transform infrared (FTIR) and UV-visible spectroscopy were also used to estimate the interactions between AMT and HMICl. AMT can treat depression, anxiety, and other mental illnesses. Imidazolium-based surface-active ionic liquids are ideal for biomedical uses because of their unique physicochemical properties. The interaction between AMT and HMICl was also examined using nonaqueous solvent systems (500 mmol center dot kg(-1) urea and 250 mmol center dot kg(-1) glucose). The ideal cmc (cmcid) measured for the mixed system (AMT + HMICl) tensiometry was notably smaller than the critical micelle concentration (cmc). As a result, AMT and HMICl interact fairly well, and interaction also increased when the a1 of HMICl increased. The cmc values for pure and mixed solutions in urea were higher than those in aqueous, while in glucose, they were lower. Hypothetical models, including those of Clint, Motomura, Rubingh, and Rosen, have been used to determine the association, interfacial, and thermodynamic properties. For each constituent, the activity coefficients were consistently < 1 for micellar along with interface, exhibiting the intermolecular interactions amongst constituents as well as nonideal behavior. The excess free energy was negative in each case, implying that mixed micelles and monolayers have higher stability than micelles and monolayers of single components. The direct interaction of AMT and HMICl was also characterized by FTIR and UV-visible analysis, similar to the tensiometric method. In summary, the ionic liquid HMICl may be an effective drug delivery vehicle. (c) 2023 Elsevier B.V. All rights reserved.