[Urea plus ceramides and vitamins: improving the efficacy of a topical urea preparation by addition of ceramides and vitamins].

Topical urea preparations containing urea have been used successfully to improve the barrier function of the skin. We investigated whether the efficacy of an urea-containing topical preparation could be improved by the addition of vitamins and ceramides. For this an intra-individual comparative study was conducted on 10 subjects with healthy skin. The application of the combination preparation containing urea, vitamins and ceramides for 2 weeks was significantly superior to the urea-only preparation in respect to reduction of transepidermal water loss and skin hydration levels. This improved efficacy was associated with a stronger up-regulation of the transcriptional expression of differentiation genes in keratinocytes in the treated skin areas. While both preparations caused an increased expression of the genes encoding transglutaminase-1, involucrin, loricrin and filaggrin, this increase was significantly greater in those skin areas treated with the combination preparation. This study indicates that the efficacy of topical preparations containing urea can be enhanced by the incorporation of ceramides and vitamins.