Methods for evaluating topical antibacterial agents on human skin.

Three procedures were presented for appraising the ability of antibacterial chemicals and formulations to suppress the growth of microorganisms on human skin. In each of these, the microflora was quantified after the skin had been occlusively covered for a day or more, a circumstance which, in the absence of a deterrent, led to an explosive overgrowth by resident organisms. The data obtained related to (i) the capacity to prevent expansion of the normal microflora, (ii) the suppression of an already expanded flora, and (iii) the persistence of antibacterial effect 3 days after the last application.