Solubility of fatty acids and other hydrophobic molecules in liquid trioleoylglycerol.

The fat solubilities of some long chain fatty acids, alcohols, alkanes, and triacyglycerols, and of some aromatic, chlorinated aromatic, and chlorinated aliphatic hydrocarbons were measured in trioleoylglycerol. Above their melting temperature, all test compounds are theoretically miscible with liquid fat. Below their melting temperature the solubility of all test compounds can be estimated by the equation: log (mole fraction solubility) = (Formula: see text) where delta Sf, the entropy of fusion, can be estimated from chemical structure according to Yalkowsky and Valvani (J. Pharm. Sci. 1980. 69:912-922), and the melting point (Tm) is either known or experimentally determined. For long chain compounds, solubility in trioleoylglycerol dropped precipitously with an increase in melting point. For the aromatic and chlorinated compounds, the drop was more gradual. Since the entropy of fusion of rigid aromatic compounds is approximately 13.5 e.u. at room temperature, their solubility in triacylglycerol is a linear function of melting point.