Disclosed herein is a composition containing: a) clay material with a negative surface charge, preferably a zeolite, in particular clinoptilolite； b) magnesium ions and calcium ions both either incorporated within the clay material and/or added separately； c) water and/or non-aqueous solvent； d) substantially non-cationic carrier； i) the mean particle size of the clay material is at least 5 nm, preferably between 5nm and 100µm； and ii) the total molar amount of magnesium ions is higher than the total molar amount of calcium ions, particularly higher than 1.2X. Also disclosed is the use of the composition as defined above in the manufacture of a medicament /medical device for the prophylaxis and treatment of skin diseases, skin conditions or mucosal diseases where the formation and/or recovery of epidermal/mucosal barrier function has beneficial effect.
