Lamotrigine solubility in 1-propanol + water mixtures at different temperatures: experimental data and mathematical modelling

ABSTRACT

The solubility of lamotrigine (LTG) was determined in {1-propanol (1) + water (2)} mixtures over a temperature range of 293.15 to 313.15 K. The measured data were correlated to cosolvency models namely Jouyban-Acree, Jouyban-Acree-van’t Hoff, combined nearly ideal binary solvent/Redlich-Kister (CNIBS/R-K), modified Wilson and Machatha models. Among the models, Jouyban-Acree with temperature and solvent composition dependencies has more accuracy rather than Jouyban-Acree-van’t Hoff model and CNIBS/R-K model with solvent composition dependency is more compatible with the experimental solubility data. Furthermore, the apparent standard molar Gibbs energy, entropy, and enthalpy of dissolution and mixing $\mathrm{\Delta }{H}_{soln}^{\circ }$, $\mathrm{\Delta }{S}_{soln}^{\circ }$, $\mathrm{\Delta }{G}_{soln}^{\circ }$, $\mathrm{\Delta }{H}_{mix}^{\circ }$, $\mathrm{\Delta }{S}_{mix}^{\circ }$ and $\mathrm{\Delta }{G}_{mix}^{\circ }$ for LTG in the studied binary mixtures were calculated based on the van’t Hoff and Gibbs free energy equations which suggest that the dissolution process is more favourable in 1-propanol-rich mixtures and proceeds entropically. Finally, preferential solvation parameters of LTG by 1-propanol were also calculated by means of the inverse Kirkwood-Buff integrals.

KEYWORDS:

• Solubility
• lamotrigine
• 1-propanol
• Jouyban-Acree model
• modified Wilson model
• solution thermodynamics
• preferential solvation

Acknowledgments

S. N. Mirheydari would like to thank for a postdoctorate grant (693118) of Tabriz University of Medical Sciences for supporting this work.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Tabriz University of Medical Sciences [693118];