UV-induced erythema model: a tool in dermatopharmacology for testing the topical activity of non-steroidal anti-inflammatory agents in man.

UV-induced erythema is a well known inflammatory model applied both in animal and human skin to test the activity of topical non-steroidal anti-inflammatory compounds in a great variety of pharmaceutical formulations. The aim of this study was to evaluate the inhibitory efficacy of piroxicam in two different topical formulations (cream 0.5, 1 and 1.5% and gel 1%) as compared to three non-steroidal compounds, benzydamine, etofenamate and indomethacin (cream 5%), on erythema induced after UV-injury on the back of 5 healthy subjects. The results showed that piroxicam in cream formulation, indomethacin cream and etofenamate gel have a similar effect, decreasing the erythema size 7 h after irradiation. However, benzydamine cream and piroxicam gel showed no effect with this method. We may conclude that this model is adequate and precise for selecting the most appropriate galenic dosage form for an active compound in terms of its clinical efficacy when topically administered.