Skin efficacy and biophysical assessment of glycerol-containing hydrocolloid patches

Hydrocolloid patches are developed with 10, 20 and 30% (w/w) glycerol as the main active ingredient. By making use of two experimental forearm models, skin efficacy and its dependency on the glycerol concentration applied were compared with a blank reference patch, a commercialized protective patch and a cosmetic barrier cream. Skin hydration and transepidermal water loss measurements were combined with skin erythema assessments. After a single application to healthy skin, a clear concentration-dependent effect of glycerol-containing patches was observed with - for the highest glycerol content - a 31% increase in skin hydration and an improvement in skin barrier properties of 15%. This glycerol-containing patch also accelerated barrier recovery of mechanically irritated skin after stripping with cyanoacrylate tape. After 7 days of repetitive application, a significantly hydrating effect of the 30% glycerol-containing patch was observed, which was of the same order of magnitude as observed for the cosmetic barrier cream, the latter being applied twice daily. The effects seen were maximal after 3 days of patch application.