Hydrophobic and solvation effects on the solubility of hydroxysteroids in various solvents Quantitative and qualitative assessment by application of the mobile order and disorder theory

摘要: Following the preliminary discussion outlining relative difficulty of experimental determination solubilities versus lack general applicability and sound theoretical basis most current predictive approaches for solubility, we look closely at recently developed pure thermodynamic model solubility in real solutions: that derived from mobile order disorder theory. With successful estimates 62hydroxysteroids related drugs common organic solvents differing polarities H-bonding capacity, has proved to be a valuable tool predicting complex solutes such as polyfunctional drugs. Free any adjusted regression coefficients based on limited number readily available parameters, proposed is time-saving alternative procedure experimentation. By properly quantifying enthalpic entropic contributions involved overall process, furthermore assesses factors determine differences between steroids changes upon solvent properties. Therefore, poor hydroxysteroids aliphatic hydrocarbons results negative effects due change non-specific cohesion forces mixing steroid self-association solution. In water, low are mainly large value hydrophobic effect which cannot overcome by steroid–water functional group associations, i.e., solvation effect. The relatively good polar non-associated (ketones, ethers, esters) alcohols explained fact that, both kinds solvents, rather well counterbalanced formation more or less important steroid–solvent interactions without being penalized strong case alcohols. Some practical rules regarding how some parameters like molar volume substitution may affect finally derived, might help pharmaceutical scientist orient choice liquid forms.