A topical skin protectant (TSP) (ICD 2289) is being developed to protect service members from exposure to
chemical warfare agents (CWA). The TSP is designed for use on the skin at the overgarment closures and other vulnerable areas to enhance protection. The TSP, which is in phase II clinical studies, is a cream containing two chemically inert substances: perfluoroalkylpolyether and
polytetrafluoroethylene. Animal data showed that the TSP was effective against percutaneous penetration of a
blister agent,
sulfur mustard (HD), by reducing the size of skin lesions and against T-2
mycotoxin by preventing the development of
erythema and
edema. The
insect repellent N,N-diethyl-m-toluamide (
DEET) reduced the TSP protection against HD regardless of the order of application on rabbit skin prior to dosing of HD. The protection was sustained when
DEET was removed with a dry gauze prior to TSP application. The TSP was also effective against percutaneous exposure of
nerve agents-thickened (with 5% methyl
methacrylamide)
soman (TGD) and
VX (O-ethyl-S-[2-(diisopropylamino)ethyl]
methylphosphonothioate )-by reducing the mortality rate and protecting the red blood cell
acetylcholinesterase activity. The TSP was effective against
VX when
DEET was applied prior to TSP application. Because human efficacy studies using CWA cannot be conducted, the efficacy will be demonstrated by the level of protection against poison ivy (
urushiol)
contact dermatitis in humans.