Study of naproxen in some aqueous solutions of choline-based deep eutectic solvents: Solubility measurements, volumetric and compressibility properties.

Naproxen (NAP) is a widely used drug for the treatment of pain and inflammatory conditions. However, there is not the physicochemical information about this drug such as solubility, volumetric and compressibility properties in the presence of deep eutectic solvents (DES) as a new class of green solvents to overcome the low solubility of drugs. In this work, the solubility of NAP is studied in the solutions containing some choline chloride (ChCl) based DES at temperature ranges (298.15-313.15) K. The results indicate that the solubility increases with increasing the concentration of DES and temperature and DES containing malonic acid is the proper co-solvent. The experimental solubility values were correlated by the e-NRTL, Wilson and UNIQUAC models. In addition, the complex interactions between the components in the systems should be elucidated, therefore, the thermodynamic properties including volumetric and compressibility properties have been investigated using density and speed of sound measurements at T = 298.15 K. According to calculated thermodynamic parameters, strong interactions between NAP and DESs are observed which is in agreement with obtained solubility data.