Investigation of the solubility and thermodynamics of ivermectin in aqueous mixtures of polyethylene glycols 200/400

Ivermectin, a poorly water-soluble drug, faces challenges like slow dissolution and variable absorption, affecting its efficacy. While some solubility data exist for ivermectin in mono-solvents and a few binary mixtures, research on its solubility in broader solvent combinations remains limited. This investigation aimed to elucidate the solubility and thermodynamic profiles of ivermectin in binary solvent systems comprising (polyethylene glycol 200 + water) and (polyethylene glycol 400 + water) within a temperature range of 293.2 to 313.2 K. The experimental solubility data were analyzed utilizing various linear and nonlinear models, including van't Hoff, Jouyban-Acree, Jouyban-Acree-van't Hoff, and mixture response surface methods. The efficacy of these models was assessed by evaluating their mean relative deviations from the experimental values. Furthermore, apparent thermodynamic parameters, including Gibbs energy, enthalpy, and entropy, were calculated using the van't Hoff and Gibbs equations.