Numerical Analysis of Sulfamerazine Solubility in Acetonitrile + 1-Propanol Cosolvent Mixtures at Different Temperatures

The current challenges of the pharmaceutical industry regarding the environmental impact caused by its waste have led to the design and development of more efficient industrial processes. In this context, solubility studies are at the core of different processes, such as formulation, preformulation, synthesis, purification, recrystallization, quantification, and quality control. This research evaluates the solubility of sulfamerazine (SMR) in acetonitrile + 1-propanol cosolvent mixtures at nine temperature levels with UV/vis spectrophotometry using the vial-shake method. According to the analysis of the solid phase in equilibrium using differential scanning calorimetry, there were no polymorphic changes. The minimal solubility of SMR was reached in 1-propanol at 278.15 K, and the maximal solubility in acetonitrile at 313.15 K. In all cases, the process was endothermic and dependent on the cosolvent composition, and the solution enthalpy drove the solution process. The solubility data were well correlated with the van’t Hoff, Yalkowsky–Roseman–van’t Hoff, Apelblat, Buchowski–Ksiazczak λ h, Yaws, NRTL, Wilson, and modified Wilson models, with the YR model being one of the most attractive because it presented an excellent prediction percentage from four sets of experimental data. The solution process of SMR in acetonitrile + 1-propanol cosolvent mixtures depends on the affinity of SMR for acetonitrile and temperature increase.