Disclosed is the use of (a) chitosan, a water soluble chitosan derivative or a physiologically acceptable salt, (b) at least a pharmaceutical or a cosmetic active ingredient selected from the group comprising corticosteroids, immunostimulants, immununosuppressants, antivirals, citostatics, antimycotics, antibiotics, antipsoriatic agents, keratolytics, retinoids, preservatives, insect repellents, antioxidants, plant extracts, or combinations thereof, and (c) at least one volatile solvent, in the manufacture of a liquid composition for treating dandruff, eczema, atopic dermatitis, psoriasis, mycoses or pityriasis versicolor； wherein said liquid composition forms a dermal film after application onto skin subsequent to evaporation of the volatile solvent (c), and wherein said composition delivers said at least an active ingredient onto the skin surface.
