Williams N A, Amidon G L
J Pharm Sci. 1984 Jan;73(1):18-23. doi: 10.1002/jps.2600730106.
The reduced three-suffix solubility equation derived from the Wohl excess free energy expression is used to describe the solubility of phenobarbital in propylene glycol-water, ethanol-propylene glycol, and ethanol-water-propylene glycol mixtures and the solubility of hydrocortisone in propylene glycol-water mixtures. Solvent-solvent interaction constants were obtained by fitting total vapor pressure versus composition data, obtained at 25 +/- 0.1 degrees C, to the Wohl excess free energy model for the solvents. The equation describes solubility in these systems satisfactorily except for phenobarbital in ethanol-propylene glycol, where the solubility is fairly high and assumptions involved in the derivation of the equation do not hold.
由沃尔过剩自由能表达式推导得出的简化三后缀溶解度方程，用于描述苯巴比妥在丙二醇 - 水、乙醇 - 丙二醇以及乙醇 - 水 - 丙二醇混合物中的溶解度，以及氢化可的松在丙二醇 - 水混合物中的溶解度。通过将在25 ± 0.1摄氏度下获得的总蒸气压与组成数据拟合到溶剂的沃尔过剩自由能模型，得到溶剂 - 溶剂相互作用常数。该方程除了在描述苯巴比妥在乙醇 - 丙二醇中的溶解度时效果不佳外（因为其溶解度相当高，且方程推导过程中的假设不成立），能令人满意地描述这些体系中的溶解度。
