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

Abstract

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 , , , , and 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.