This study presents a detailed investigation of the interaction between the ionic liquid 1-hexyl-3-methylimidazolium chloride (HmimCl) and an antibiotic cloxacillin sodium (CLX). Binding interactions were explored using both equilibrium and dynamic surface tension measurements at temperatures of 298 K, 303 K, and 308 K. The equilibrium surface tension method was utilized to study the interfacial and thermodynamic properties of micellization of pure HmimCl and HmimCl-CLX at the air-water interface. Dynamic surface tension measurements were carried out for both HmimCl and HmimCl-CLX systems over time. These measurements helped assess the influence of the DST values and other related kinetic parameters for both systems. Additionally, dynamic light scattering was used to determine the hydrodynamic diameter (Dh) of HmimCl aggregates and the drug-loaded micelles. The stability of the HmimCl-CLX complex was assessed through zeta (ζ) potential measurements, where a decrease in ζ values indicated that the interaction between HmimCl and CLX is primarily electrostatic in nature. Furthermore, the interaction between CLX and HmimCl was quantitatively examined using steady-state fluorescence and UV-visible spectroscopy. To complement and validate these experimental observations, classical density functional theory (DFT) calculations were also performed. Together, the combined spectroscopic, dynamic, and theoretical analyses provide strong evidence of a stable and energetically favorable interaction between CLX and HmimCl, highlighting their potential for drug delivery or molecular binding applications.
Siddiquee et al. (Wed,) studied this question.