Chemical M&A rebounded in 2018

Abstract

The solubility values of doxifluridine in three mixed solvents of (±)-2-ethyl-1-hexanol + (methanol, ethanol and acetone) ware determined within 278.15–328.15 K under 0.1 MPa using a laser monitoring technique. It can be seen from the solubility profiles that all the solubility of doxifluridine in the mixed solvents increases with the increasing mass fraction of the co-solvent (methanol, ethanol or acetone) and the experimental temperature. The minimum and maximum mole fraction solubility of doxifluridine was found in ethanol + (±)-2-ethyl-1-hexanol (4.981 × 10−5 at w1 = 0.1003, T = 278.15 K) and methanol + (±)-2-ethyl-1-hexanol (1.109 × 10−1 at w1 = 0.9001, T = 328.15 K), respectively. Through the application of Hansen solubility parameters, the solubility order and miscibility of doxifluridine in the three mixed solvents studied in this work was revealed, and the results showed that the dissolution behavior of doxifluridine was not only determined by a single factor, but also the result of the comprehensive action of various solubility parameters. In addition, three semi-empirical models (λh, Modified Apelblat, and MA) and one activity coefficient model (UNIQUAC) were applied to fit the solubility data of doxifluridine. The minimum average values of ARD (average relative deviation) and 104 RMSD (root-mean square deviation) were acquired from Modified Apelblat model, verifying that Modified Apelblat model provides maximum consistency among the four models. Furthermore, Van't Hoff model was used to calculate the apparent thermodynamic parameters (ΔsolG°, ΔsolH°, ΔsolS°) of the dissolution process of doxifluridine. The results demonstrated that the dissolution process of doxifluridine in all the three mixed solvents studied was an entropy-driven endothermic process.