An experimental evaluation of the germicidal efficacy of three topical antimicrobial agents in burns

The bacteriocidal effect of three substances is discussed: 10% povidone iodine ointment (Betadine, betaisodona), 11,2% mafenide acetate (Naplatan) and silver sulphadiazine (Flamazine, Silvadene, Silvertone). A modified Walker burn model using male Long-Evans rats was studied. The infections were produced with a solution of 3 times 10(8) Pseudomonas aeruginosa pyocin type H. organisms. The authors described the pharmacological properties of the three substances and report the following results. All three substances are able to penetrate third degree burns. It takes 4 hours for povidone iodone, 12 for mafenide acetate and 24 for silver sulphadiazine to penetrate the burn. Mafenide acetate and silver sulphadiazine were the most useful agents after 12 and 24 hours respectively. When the substances were applied for a second time 24 hours after the first application only mafenide acetate was highly effective. The effectiveness of povidone iodine and silver sulphadiazine decreased by half when compared with the first application. For practical purposes the following recommendations are made: For deep burns povidone iodine should be applied every 4--6 hours, mafenide acetate every 12--18 hours and silver sulphadiazine once every 24 hours in order to ensure an antibacterial effect.