Solubility and thermodynamic properties of amlodipine besylate in two binary mixtures of n-methyl pyrrolidone + 1-propanol/2-propanol at different temperatures.

In this study, the solubility of amlodipine besylate in N-methyl-pyrrolidone/1-propanol and N-methyl-pyrrolidone/2-propanol binary mixture systems were measured using a common shake-flask method followed by spectroscopy analysis at temperature ranges from 298.2 K to 313.2 K. The generated data were fitted to some models, van't Hoff, Jouyban-Acree, Jouyban-Acree-van't Hoff, mixture response surface, and modified Wilson, to mathematical representation the solubility data. Finally, the apparent thermodynamics properties for the saturated mixtures were computed using van't Hoff and Gibbs equations.