Solubility of Lamotrigine in Polyethylene Glycol 400 + 2-Propanol Mixtures at Different Temperatures

In this study, the shake-flask method was used to determine the solubility of lamotrigine (LTG) in non-aqueous mixtures of polyethylene glycol 400 (PEG 400) and 2-propanol at temperatures of 293.15 to 313.15 K. Five main mathematical models were used to correlate the experimental data. The overall mean relative deviations for these models were less than 18.7 %. In addition, the apparent thermodynamic properties of LTG dissolution were computed. It is found that the LTG dissolution in PEG 400-rich mixtures is more favorable and proceeds entropically. Both experimental and mathematical methods were used to determine the density of LTG-saturated solutions. The results showed that the Jouyban–Acree model could be used to predict the density of LTG saturated solutions in mixtures with a very good approximation (back-calculated MRD% of 0.4).