A Green Innovative Approach for Solubility Enhancement of Poorly Water-Soluble Drugs Using Choline Chloride–Polyol Eutectic Solvents

Eutectic solvents have become a viable choice to create innovative pharmaceutical technologies within the framework of the green chemistry approach. Despite the growing applicative interest, a general gap remains in the pharmaceutical sector regarding thorough and systematic research of their properties and useful applications. In this work, eutectic solvents have been prepared from choline chloride and polyols (sorbitol, xylitol, mannitol, and isomalt) at different molar ratios (1:1, 2:3, and 3:2), characterised, and used for the solubility enhancement of poorly water-soluble drugs (ibuprofen and naproxen) as well as the potential drug candidate apigenin. The interactions between the eutectic solvent components were investigated by DSC, FTIR, and refractive index methods. In all eutectic solvents, the water content detected by Karl Fischer titration and loss on drying was less than 3%. Solubility studies, carried out using the shake-flask method, showed significant solubility enhancement of the following: ibuprofen: ~152-fold increase, naproxen: ~144-fold increase, and apigenin: ~188-fold increase. These findings highlighted the great potential of eutectic solvents as solubility enhancers in the development of novel and more effective drug delivery systems.