ABSTRACT. Binding of cetylpyridinium chloride (CPC) to a nonionic, non‐surface active macromolecule, polyethylene glycol 20 M (PEG), has been investigated by equilibrium dialysis and a microbiological viable count technique. The results indicate that the bactericidal activity of CPC in aqueous solutions of the PEG cannot be simply equated with the activity of free aqueous CPC. The activity was found to be equal to or greater than that expected from the binding data depending on the CPC concentration. The implications of the experimental findings are discussed.

No abstract

ABSTRACT. Binding of benzoic acid to a nonionic polyoxyethylene surfactant has been investigated by equilibrium dialysis and a microbiological viable count technique. The results indicate that the antimicrobial activity of benzoic acid in this solubilized system can be equated with the free acid in solution in the aqueous phase. Potentiation by low concentrations of several nonionic macromolecules does not occur.