Mafenide acetate has been studied using human and animal tissue. It behaves similarly in burned tissue of both species, rapidly penetrating the burn wound. Eighty to ninety percent of the dosage enters the wound within five hours and attains a peak concentration at one to two hours, two to five times that required for minimal bacterial inhibition. The drug declines in concentration in the wound to subinhibitory levels in eight to ten hours, requiring reapplication at that time for maximum effectiveness. Six to eight percent of the drug is bound by plasma protein. Its excretion is principally by the kidney, with halftimes in all organs and plasma of 10 to 15 minutes, and total excretion within six days. The drug strongly inhibits protein synthesis in Pseudomonas aeruginosa.