[Skin tolerance of topical corticoids as dependent upon the pH value of the emulsions].
Two new hydrocortisone esters, EMD 33 702 and EMD 33 714, each with an activity of 0.1% concentration approximately equivalent to that of 1% hydrocortisone acetate were selected for the development of new topical corticoid preparations. The stability of these steroids is dependent on the pH value of the vehicles. Thus, it was necessary to adjust the pH values in the tested creams (Cremegrundlage a, Cremegrundlage IXa) to pH 8 for EMD 33 702 and to pH 4 for EMD 33 714. In order to assess the skin tolerance of these creams the following investigations on human skin have been carried out. 1. During chamber test on normal skin (14 d) and 2. on scarified skin (3 d); 3. Test on the functions of the horny layer before and after 3 weeks treatment (alkali resistance test, nitrazin test after stripping, ammonium hydroxid blister test; n = 8). Additionally, vasoconstriction tests were carried out to assess the activity as a function of the different pH values in the cream formulations. The skin tolerance of the creams a and IX a and their steroid containing preparations was good on normal as well as on scarified skin. Differences in skin tolerance dependent on the pH value of the creams (pH 4-pH 8) could not be determined. Compared with this a cream with 10% carbamide (pH 8) was very irritating and scarified skin and a cream with 10% carbamide and 5% lactic acid showed very irritating reactions on normal and scarified skin respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
D000287:Administration, Topical; D000893:Anti-Inflammatory Agents / Q000009:adverse effects*; D004655:Emulsions; D005938:Glucocorticoids; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007509:Irritants; D012867:Skin / Q000187:drug effects*; D014662:Vasoconstrictor Agents
D000893:Anti-Inflammatory Agents; D004655:Emulsions; D005938:Glucocorticoids; D007509:Irritants; D014662:Vasoconstrictor Agents
Die Hautverträglichkeit von Corticoid-Externa in Abhängigkeit vom pH-Wert der Emulsionen.