Solubility enhancement and intermolecular interactions of salicylic acid in aqueous solutions of choline chloride based deep eutectic solvents

Novel categories of solvents, deep eutectic solvents (DESs) as greener alternative media to hazardous organic solvents, have received great attention in numerous fields of science and technology. The poor aqueous solubility of many drugs with adequate bioavailability is still one of the main challenges in pharmaceutical sciences. In this regard, the aim of the present study is to measure the solubility and investigate the molecular interactions between salicylic acid (SA) and some choline-based DESs containing choline chloride (ChCl) with urea (U), ethylene glycol (EG), and glycerol (G). The experimental solubility of SA was measured in water, and aqueous solutions of DESs at several temperatures, and the computational studies have been used to get a deep insight into the molecular interactions among DESs and SA. The results indicate that the experimenral ant theoretical results are consistent and also the solubility of SA in DESs was increased significantly. The DESs can also alter the pH of the solution and cause the increase of SA solubility. (C) 2022 Elsevier B.V. All rights reserved.