Paracetamol in aqueous solutions of polymeric-based deep eutectic solvents; solubility, partitioning, volumetric and compressibility studies

Highlights: • Determination of paracetamol solubility in aqueous ChCl/PEG300 or 600 solutions. • The efficiency of polymeric-based DESs on the extraction of PCM was investigated. • The interactions of components in the systems were evaluated using volumetric properties. • The ChCl/PEG300 was the better solvent than ChCl/PEG600 for PCM solubility and extraction. Paracetamol (PCM) is a widely used nonprescriptive analgesic and antipyretic agent. However, the low aqueous solubility of this drug is an important issue that mainly affects the extent of oral bioavailability, desirable formulation, and extraction process. Alternatively, deep eutectic solvents (DESs) as new green and sustainable category of solvents can be used to overcome the low solubility of drugs. The purpose of this research was three-fold. First, the solubility of PCM was investigated in the aqueous mixture of DESs containing choline chloride (ChCl) and polyethylene glycol (PEG300 or 600) at 298.15 K, and the partitioning of PCM from aqueous solutions was studied in aqueous two phase system for the second one. Finally, the volumetric and compressibility properties of the PCM in the water + DESs mixtures were studied to evaluate the interactions between the components of the systems. The evaluation results on three different test sets showed that the three measurement processes are very consistent, which demonstrated that the solubility and the partitioning yield of PCM in the presence of ChCl/PEG300 are higher than ChCl/PEG600. Also, according to calculated thermodynamic volumetric and compressibility properties, strong interactions between PCM and DESs are observed and the data is in agreement with measured solubility data.