Significant Increase in the Solubility of Celecoxib in Presence of Some Deep Eutectic Solvents as Novel Sustainable Solvents and the Thermodynamic Analysis of These Systems

Abstract

Background: Deep eutectic solvents (DESs) exist a wide variety of potential and existing applications. Based on the fact that the choline chloride (ChCl) is a complex B vitamin and widely used as food additive, the choline-based DESs are generically regarded as being harmless and non-toxic. In this regard, the low aqueous solubility of celecoxib (CLX) have been increased by use of DESs as neoteric class of solvents at T = (298.15 to 313.15) K. Methods: DESs were prepared by combination of the ChCl/EG, U and G with the molar ratios: 1:2 and ChCl/MA with 1:1. The shake flask method was used to measure the solubility of CLX in the aqueous DESs solutions at different temperatures. Results: The solubility of the CLX increased with increasing the weight fraction of DESs. The observed solubility data was subjected to evaluate the relative performance of a number of models including Apelblat, Yalkowsky and Jouyban–Acree models for their correlation efficacy. Moreover, the apparent dissolution enthalpy, entropy and Gibbs free energy were obtained from the experimental solubility values. Conclusion: It was found that the solubility data was satisfactorily fitted using the mentioned models at different temperatures. The dissolution process of CLX in the studied solvent mixtures within investigated temperature range was endothermic, and the driving mechanism is the positive entropy.

Keywords

• deep eutectic solvent
• solubility
• jouyban–acree model
• dissolution thermodynamics