Abstract
The solubility and dissolution thermodynamics of (2Z)-N-cyclohexyl-2-(3-hydroxybenzylidine) hydrazine carbothioamide (CHBH) in various 2-(2-ethoxyethoxy)ethanol + water mixtures from (298.15 to 338.15) K were studied in the present investigation. The solubilities of CHBH were measured using an isothermal method. The experimental solubilities of CHBH were correlated with Apelblat equation and log-linear model of Yalkowsky. The root mean square deviations (RMSD) were observed in the range of (0.41 to 5.34) % and (0.98 to 3.15) % for Apelblat equation and Yalkowsky model, respectively. The correlation coefficients were found to be 0.996 to 0.999 in co-solvent mixtures investigated. The data of RMSD and correlation coefficients indicated good correlation of experimental solubilities with Apelblat and Yalkowsky models. The mole fraction (93.80 x 10(-3) at 298.15 K) and mass fraction solubility (0.21 kg degrees kg(-1) at 298.15 K) of CHBH were observed highest in pure 2-(2-ethoxyethoxy)ethanol. However, the lowest mole fraction (3.90 x 10(-7) at 298.15 K) and mass fraction solubility (6.00 x 10(-6) kg . kg(-1) at 298.15 K) of CHBH were observed in pure water. Dissolution thermodynamic studies indicated that the dissolution of CHBH was endothermic in all co-solvent mixtures investigated. Based on these results, CHBH has been considered as freely soluble in 2-(2-ethoxyethoxy) ethanol and practically insoluble in water. (C) 2014 Elsevier B.V. All rights reserved.