Abstract
Data have been presented to prove that high solubilization of p-hydroxybenzoic acid ester is demonstrated by the nonionic surfactant which has a suitable ratio of hydrophilic to lipophilic affinity in regard to the property of the ester. The condensed molar number of ethylene oxide in a surfactant which exhibits a maximum inactivation against p-hydroxybenzoic acid ester decreases with an increase in the carbon number of the ester group, i.e. methyl, ethyl, propyl, and butyl. Moreover, it is understood that the ability of solubilization is dependent upon the property of the surfactant, particularly upon the chemical structure of its lipophilic group. Therefore, degree of inactivating effect on Parabens differs according to the type of surfactants. e.g., TO-, BO-, and NP-type. The results obtained in the present series of experiments give a reasonable support to the conclusion that the antifungal activity of p-hydroxybenzoic acid ester in the presence of a surfactant is represented only by what is present in aqueous phase outside the micelle.
