Study on dissolution behavior of naphazoline nitrate in four binary solvents: Determination, modeling, Hansen solubility parameter and thermodynamic analysis

Solubility data of naphazoline nitrate in four binary solvents namely methanol/2-methoxyethanol/ethy lene glycol/N,N-dimethylformamide plus isopropanol was determined in temperature range of (278.1 5 ti 323.15) K under 0.1 MPa. The laser monitoring method was employed during solubility determina-tion process, and the composition of positive solvent was ranged from 0 to 1.0 with the mass fraction interval about 0.1. Solubility values showed an obvious growth trend with the increase of temperature, at the same time, it also had positive correlation with incremental mass fraction of positive solvent. The maximum as well as minimum values of naphazoline nitrate solubility data were obtained in neat N,N-dimethylformamide at 323.15 K (0.1855) and isopropanol at 278.15 K (5.766e-4). Besides, solubility modeling was realized by four activity coefficient models namely Margules, Wilson, NRTL, UNIQUAC model, and four selected models could provide good fitting effect among solubility data, solvent compo-sition and experimental temperature. Corresponding root mean square deviation and average relative deviation between experimental and computed solubility data were not more than 2.759 parts per thousand and 6.727%, respectively. Moreover, Hansen solubility parameter were applied for discussing the miscibility between NPZN and selected solvents. Furthermore, thermodynamic properties, i.e. Gibbs free energy, entropy and enthalpy, for dissolution process and mixing process, were evaluated by UNIQUAC model. Results showed that dissolution processes were spontaneous and entropically driven, at the same time, most of mixing processes excluding naphazoline nitrate in isopropanol and methanol were spontaneous, exothermic and entropically driven.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

The solubility data of naphazoline nitrate in four binary solvents were determined using the laser monitoring method at temperatures ranging from 278.15 K to 323.15 K. The solubility values increased with temperature and the mass fraction of the positive solvent. Four activity coefficient models provided good fitting for the solubility data. The miscibility between naphazoline nitrate and selected solvents was discussed using Hansen solubility parameters. Thermodynamic properties of the dissolution process and mixing process were evaluated using the UNIQUAC model.