Measurement and Correlation of the Solubility of Florfenicol Form A in Several Pure and Binary Solvents

The solubility of florfenicol form A in eight pure organic solvents (propionic acid, ethanol, 1-propanol, 1-butanol, 2-propanol, 2-methyl-1-propanol, 3-methyl-1-butanol, and 2-ethyl-1-hexanol) and three binary solvents (dimethyl sulfoxide + ethanol, dimethyl sulfoxide + 1-propanol, and dimethyl sulfoxide + 1-butanol) was measured by a laser dynamic method at temperature from 283.15 to 323.15 K. The experimental results show that the mole fraction solubility of florfenicol in the pure solvents decreased according to the following order: ethanol > 1-propanol > 2-propanol > 1-butanol > 3-methyl-1-butanol > 2-methyl-1-propanol ≈ propionic acid > 2-ethyl-1-hexanol. The experimental results show that the mole fraction solubility of florfenicol form A in the binary solvents increased with the increase of temperature and dimethyl sulfoxide mass fraction. The experimental solubility data were well correlated with the four thermodynamic models: modified Apelblat equation, λh equation, NRTL model equation, and Wilson model equation. The modified Apelblat model equation was regarded as the best one to fit the experimental values in the pure solvents.