Provided is a foam-forming formulation and method of treating an infection in a body cavity. The foam-forming formulation contains hydrogen peroxide, monoglyceride crystals, at least one acid and/or buffer which is present in an amount to provide a pH of 3 to 5 within a body cavity, a blowing agent in an amount to blow the foam-forming composition and form a foam, and water. The foam-forming composition is suitable application to body cavity when blown to form the foam and the form degrades at a body temperature to release the hydrogen peroxide to tissues in the body cavity at a pH of 3 to 5. Also provided is a foam-forming composition vehicle for delivering an active agent.