Bacterial Susceptibility to Butyl p-Hydroxybenzoate in the Presence of Polyoxyethylene Cetyl Ether

Abstract

The effects of polyoxyethylene cetyl ether on the antibacterial activity of butyl p-hydroxybenzoate (BP) were studied using five strains of bacteria. The antibacterial activity of BP in an aqueous solution was inhibited by the non-ionic surfactant due to a decrease in unbound BP in an aqueous phase resulting from the incorporation of BP into surfactant micelles, whereas it was greater than that anticipated from unbound BP. Non-ionic surfactant was thus concluded to increase the susceptibility of bacteria against BP due to direct interactions with the cells.