Evaluation of the inhibitory activity of topical indomethacin, betamethasone valerate and emollients on UVL-induced inflammation by means of non-invasive measurements of the skin elasticity.

BACKGROUND/AIM: Topical indomethacin has been reported to inhibit ultraviolet light-induced erythema. The objective of this study was to verify this assertion and to compare indomethacin 10% ointment to beta-methasone valerate 0.1% ointment, water-in-oil emulsion and oil-in-water emulsion by means of non-invasive skin elasticity measurements.

METHODS: Products were applied on the back skin 60 min and 5 min before and 5 min after UVL irradiation. Untreated test sites served as controls. Clinical evaluation, measurements of epidermal hydration (Corneometer) and mechanical properties of the skin (Cutometer) were made 1 h before and 24 h after exposure.

RESULTS: Test areas treated with indomethacin 60 min and 5 min before irradiation showed the significantly lowest visual erythema scores and no significant changes in skin mechanical parameters. At all other test sites, a significant decrease in elasticity parameters (Ue, Ur, Ua/Uf, Ur/Uf) and an increase in viscoelasticity parameters (Uv, Uv/Ue) of the skin were observed. No significant changes of epidermal hydration were found at any of the test sites.

CONCLUSION: The inhibitory action of topical indomethacin on UVL-induced inflammation is superior to beta-methasone valerate and emollients. Non-invasive measurement of skin elasticity could be used as a supplementary tool for objective evaluation and comparison of the photoprotective activity of different topical agents.