of salt and lipid which are important constituents of the human skin environment this indicates the likely activity of the compound as an anti acne agent the propionibacteria being implicated in acne example 1 was repeated using other alkyl sulphates and sulphonates as the test compounds namely a lithium dodecyl sulphate sodium 7 ethyl 2 methyl 4 undecyl sulphate sodium octyl sulphate trizma u00ae 2 amino 2 hydroxymethyl 1 3 propanediol also known as u2018 tris u2019 dodecyl sulphate sodium octadecyl sulphate sodium 1 octane sulphonic acid sodium 1 butane sulphonate sodium 1 decane sulphonate sodium 1 heptane sulphonate sodium hexane sulphonate sodium 1 nonanesulphonate sodium pentane sulphonate sodium 1 propanesulphate monohydrate sodium dodecyl sulphate sds and ammonium dodecyl sulphate ads all supplied by sigma aldrich uk b sodium decyl sulphate sodium tridecyl sulphate sodium n pentyl sulphate and sodium n hexyl sulphate all supplied by acros organics uk c sodium hexadecyl sulphate sodium 1 dodecanesulphonate sodium 1 pentadecane sulphonic acid sodium 1 hexadecane sulphonate sodium 1 octadecane sulphonic acid sodium 1 tetradecane sulphonic acid and sodium 1 tridecane sulphonic acid all supplied by tokyo chemical industry uk ltd uk and d sodium n nonyl sulphate triethanolamine lauryl sulphate sodium n undecyl sulphate and sodium n heptyl sulphate all supplied by chemos gmbh germany all of the test compounds were dissolved in distilled water with the exception.