Release of formaldehyde from polynoxylin and noxythiolin

Polynoxylin and noxythiolin (Anaflex and Noxyflex) have been recommended for the treatment of certain bacterial infections. Both compounds were shown to release formaldehyde. Detailed studies with noxythiolin showed that it decomposed in solution to liberate most of its formaldehyde, and that solutions of formaldehyde of the appropriate strength gave zones of inhibition on seeded plates comparable in size with those given by noxythiolin. It is suggested that the effects observed with these compounds are caused by the formaldehyde released.