Thermodynamic properties of metamizol monohydrate in pure and binary solvents at temperatures from (283.15 to 313.15)K

The thermodynamic properties of metamizol monohydrate in pure solvents (methanol, ethanol, n-propanol and isopropanol) and two binary mixed solvent systems including (methanol + ethanol) and (methanol + isopropanol) were measured from 283.15 K to 313.15 K by gravimetric method under atmospheric pressure thought as 0.1 MPa. The modified Apelblal. equation, the CNI135/R-K equation, the Hybrid model and the NRTL model were used Lo correlate the solubility of metamizol monohydrate, respectively. The resifts show thaL the solubility of metamizol monohydraLe in all the tested solvents increases with the rising Temperature which means that it has temperature dependence. What's more, the effects of components of the binary solvent mixtures on solubility were discussed, it illustrates that the increasing of the molar fraction of methanol gives the system a greater dissolving power. Furthermore, according to the NRTL model, the enthalpy, the Gibbs energy and the entropy of the mixing process were also obtained and discussed. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.