Mechanisms of cutaneous vesication: Detection of sulfur mustard bis(2-chloroethyl) sulfide and metabolites after topical application in the isolated perfused

The purpose of this study was to develop an assay to study the flux of sulfur mustard (HD) through the skin and determine if metabolites are formed due to the epidermal metabolism of HD after topical exposure of the isolated perfused porcine skin flap (IPPSF) to 14C-HD. Four IPPSFs were topically dosed with 2.85 mg of 14C-HD in ethanol. Venous perfusate samples were collected and added to a 34% solution of NaCI and snap-frozen to inhibit the metabolism of RD until time for assay. Perfusate samples were extracted using a solid-phase extraction cartridge with ethyl acetate and then assayed using gas chromatography. Two of the 4 IPPSFs showed detectable levels of RD in the venous perfusate 15 min after dosing, with 1 of these 2 IPPSFs showing detectable levels of RD in the perfusate 2 hours after dosing. All 4 IPPSFs had no more than 3 metabolites of RD appearing in the perfusate throughout the 2 hr experiment, with one of those metabolites identified as thiodiglycol. These experiments showed that little, if any, RD appears in the venous perfusate intact after percutaneous absorption and that epidermal metabolism of RD does occur to a significant degree in the IPPSF.