Equilibrium solubility and thermodynamic study of daminozide in twelve neat solvents from (283.15 to 323.15) K

In the present study, solubility of daminozide was determined in twelve neat solvents (N,N-Dimethylformamide (DMF), 2-methoxyethanol, N-Methyl-2-pyrrolidone (NMP), 2-ethoxyethanol, Acetonitrile (MeCN), 2-propoxyethanol, methanol, ethanol, n -propanol, i -propanol, n -pentanol, 2-butoxyethanol) by using the gravimetrical method under the pressure of 0.1 MPa and temperature from 283.15 to 323.15 K. The maximum solubility value (10 2 x 1 ) of daminozide was found in NMP at 323.15 K (10.04), while the minimum solubility value (10 2 x 1 ) of daminozide was found in n -pentanol at 283.15 K (0.0149). At the temperature of 298.15 K, the order of the experimental solubility values (100 x 1 ) of daminozide in twelve neat solvents was: NMP (5.523) > DMF (3.294) > methanol (1.395) > 2-methoxyethanol (0.7839) > ethanol (0.5515) > 2-ethoxyethanol (0.3816) >  n -propanol (0.2175) >  i -propanol (0.1099) > 2-propoxyethanol (0.1083) > 2-butoxyethanol (0.0632) > MeCN (0.0386) >  n -pentanol (0.0344). Five models including van't Hoff model, Buchowski-Ksiazczak λh model, NRTL model, UNIQUAC model and Jouyban model were employed to correlate and analyze the experimental solubility of daminozide. Based on the principle of similar compatibility, the miscibility of daminozide in the selected solvents was discussed with the help of Hansen solubility parameters ( HSPs ). Finally, the apparent thermodynamic properties were investigated and results indicated that the dissolution mechanism of daminozide in all selected solvents was an entropy-driven and endothermic process.