A thermodynamic method of predicting the transport of steroids in polymer matrices

Abstract Application of Hildebrand's theory of the solubility of microsolutes in ordinary solvents, and of the Flory‐Huggins theory to the solubility of steroids in polymers, has permitted the derivation of a predictive correlation between polymer permeability and steroid crystalline melting temperature, other correlating parameters being the entropy of fusion of the steroid and the (computed) solubility parameters of steroid and polymer. The correlation permits prediction of the permeability of any steroid in any polymer with reasonable accuracy.