• In a double-blind triple cross-over clinical study, 37 patients were exposed to several formulations of mafenide acetate (Sulfamylon Cream) and their pain responses were recorded and converted to a semiquantitative pain index.
The 11.2% concentration in cream was two to three times more painful than the 5% concentration. Hypertonicity and not the pH level appears to be the cause of the pain produced by the high (11.2%) concentration. The tonicity of the cream carrier and 11.2% mafenide acetate are 1,080 mOsm/kg and 1,100 mOsm/kg, respectively, for a total of 2,180 mOsm/kg.
The carrier cream without glycerol and a 5% concentration of mafenide cream were much less painful than the 11.2% concentration of mafenide. Both afforded a great deal of relief to the patients who received the medications.
(Arch Surg 110:1446-1449, 1975)