Solubility of Zaltoprofen in Five Binary Solvents at Various Temperatures: Data Determination and Thermodynamic Modeling

The solubility of zaltoprofen in binary {2-methoxyethanol (ME) + ethyl acetate (EAC)/ethanol (ET), 2-ethoxyethanol (EE) + ethyl acetate (EAC)} from 278.15 to 323.15 K and 1,4-dioxane (Diox) + ethyl acetate (EAC)/ethanol (ET) from 288.15 to 323.15 K was determined using the dynamic method under 0.1 MPa. The Hansen solubility parameter provided a reasonable explanation for the dissolution behavior of zaltoprofen. Three new crystal forms appeared during the dissolution process. Then, the Jouyban–Acree model, the Jouyban–Acree–van't Hoff model, the Jouyban–Acree–Apelblat model, the Sun model, and the Ma model closely correlated with the measured solubility data. As a result, the Ma model and the Sun model provided better fitting. The basic data could provide support for industrial design and purification optimization process of zaltoprofen.