Solubility measurement and thermodynamic modeling of carbamazepine (form III) in five pure solvents at various temperatures

In this work, the solubilities of carbamazepine (CBZ) (form III) in ethyl acetate, methyl acetate, ethylene glycol, chloroform and cyclohexylamine were determined by laser monitoring techniques at pressure above sea level, and the solubility data of CBZ (form III) in different pure solvents were fitted by the Modified Apelblat model and λh model. The result shows that the solubility of CBZ (form III) in five solvents increases as temperature rises, and the solubility in chloroform was the largest. The experimental solubility values of CBZ (form III) in ethyl acetate, methyl acetate, chloroform and cyclohexylamine were in better agreement with the simulated fitting values of the λh model. For ethylene glycol, the σ value was much larger than the other four solvents, and it can be seen from the λh model that ethylene glycol was closer to the ideal solution system than the other four solvents.