Percutaneous absorption and metabolism of Irgasan® DP300

Abstract

Studies are reported on the localisation and quantitative distribution of radioactively labelled Irgasan® DP300 in guinea pig and human skin, on the percutaneous absorption of DP300 from soap suspensions applied to guinea pig skin, and on the metabolic fate of DP300 injected intraperitoneally to rats and guinea pigs. [ 14C] DP300 or [ 3H] DP300 was applied to gunea pig skin in suspensions of conventional and superfatted soaps and of toilet bars containing 10% non-soap detergent under various conditions, e.g. freshly prepared or equilibrated suspensions, single or multiple washes, various concentrations of germicide. Of the applied germicide most was removed in the rinse water. The remainder was deposited on the skin surface and some penetrated into the epidermis, pilosebaceous system and dermis. Small amounts were present in blood and body tissues and in the excreta. The pattern of localisation in human skin was similar to that in guinea pig skin except that none was seen in the pilosebaceous system. The amounts present were smaller than in guinea pig skin and the rate of disappearance from skin was rapid. The germicide given intraperitoneally, was excreted in the urine and faeces of both guinea pigs and rats. No radioactivity was present in the expired breath. In the guinea pigs more radioactivity was present in the urine than in the faeces whereas in the rat the proportions were reversed. The urines contained mostly the glucuronide of DP300. Extrapolations to the safety in use for the human are made based on the guinea pig absorption data.