Two-Phase Method for the Investigation of Interphase Transport II: Experimental Aspects

Abstract

A series of experiments were conducted to demonstrate the validity of the baseline considerations presented in the accompanying communication and the usefulness of the combined experimental and theoretical approach in more complex situations. The experimental apparatus consisted of a water-jacketed chamber with controlled agitation. The lipid sink was prepared by saturating a filter with either dibutyl sebacate, hexadecane, or a combination of these oils with a polymer. A lipid sink made from a polymer-oil gel without the filter matrix was also used. A number of solutes which included diethyl phthalate, dinitrotoluene, and cholesterol were employed. The experimental results were found to be consistent with the predictions of theory. All solutes followed firstorder behavior when the oil-water partition coefficient was large. For moderate partition coefficient values it was necessary to account for the solute buildup in the oil at the interface. In order to explain the absorption of cholesterol from a 0.10% aqueous polysorbate 80 solution of cholesterol, an interfacial barrier was proposed.