Solid-liquid equilibrium solubility, correlation, solvent effect, and thermodynamic analysis of fluoxetine hydrochloride in eight pure solvents at different temperatures

Solubility of fluoxetine hydrochloride was determined in eight pure solvents (methanol, ethanol, n-hexanol, n-octanol, N,N-dimethylacetamide (DMA) ,N,N-dimethylformamide (DMF), dimethyl sulphoxide (DMSO), and acetic acid) by a gravimetric method under 0.1 MPa at a temperature range from 283.15 to 323.15 K. Results indicated that the experimental mole fraction solubility order of fluoxetine hydrochloride in solvents at 298.15 K was: acetic acid (0.11883) > DMSO (0.10439) > DMA (0.091201) > DMF (0.083016) > methanol (0.06148) > ethanol (0.024259) > n-hexanol (0.007056) > n-octanol (0.005391), and solubility increased with temperature increasing. The Modified Apelblat equation, λh equation, Van’t Hoff equation, Yaws equation, NRTL equation, Wilson equation, Margules equation, and Van Laar equation were applied to correlate the experimental data of fluoxetine hydrochloride and analyse solubility data. Furthermore, apparent thermodynamic properties of standard molar enthalpy, molar Gibbs free energy, and molar entropy on fluoxetine hydrochloride in solution were discussed. These study results are useful for crystallisation operation of fluoxetine hydrochloride for purification and separation.