Solid–Liquid Equilibrium Measurements for Posaconazole and Voriconazole in Several Solvents between T = 278.2 and 323.2 K Using Differential Thermal Analysis/Thermal Gravimetric Analysis

Solid–liquid equilibrium measurements for systems of posaconazole (4-[4-[4-[4-[[(3R,5R)-5-(2,4-difluorophenyl)-5-(1,2,4-triazol-1-ylmethyl)oxolan-3-yl]methoxy]phenyl]piperazin-1-yl]phenyl]-2-[(2S,3S)-2-hydroxypentan-3-yl]-1,2,4-triazol-3-one) and voriconazole ((2R,3S)-2-(2,4-difluorophenyl)-3-(5-fluoropyrimidin-4-yl)-1-(1,2,4-triazol-1-yl)butan-2-ol) in 10 pure solvents was determined by equilibration and subsequent analysis by differential thermal analysis with thermal gravimetric analysis (DTA/TGA) within the temperature limits T = 278.2–323.2 K at a pressure of 0.101 MPa. The temperatures and heats of fusion of the solutes were also measured by DTA/TGA. The maximum solubility for posaconazole and voriconazole was in dimethyl sulfoxide at T = 323.2 K. The minimum solubilities were in water at T = 278.2 K. In all the measured systems, the solubility increases nonlinearly with temperature. The solubility data was successfully correlated using the nonrandom two-liquid model and the modified Apelblat equation.