Abstract: The invention relates to a pharmaceutical composition for removing necrotic skin tissue in mammals, including humans. The composition comprises in combination a substituted thiol in which the hydrogen sulfide moiety is substituted by an organic residue, alantoine, a physiologically acceptable alkaline substance, an application vehicle for the thiol and alkaline constituents, and water for activating the composition. Suitable application vehicles are body giving materials of an oily nature, emulsifiers and a thickening agent, with adequate water to provide the required consistency. Suitable thiols are thioglycolates and similar compounds.