The inventive composition comprises an active ingredient, for example a quaternary ammonium compound, which active ingredient is capable of inhibiting or destroying a unicellular living organism, such as spermatazoa, bacteria or virus. The active ingredient is combined in a synergistic amount with an activating ingredient capable of inhibiting or destroying the enzymes associated with the unicellular organism. The activating ingredient may be capable of releasing fluoride ions, for example, an inorganic fluoride compound. The composition according to the invention is useful, for example, as a spermicide, or as an antibiotic, or as an anti-STD preparation for local or topical application.
