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Validation of an in vivo wound healing model for the quantification of pharmacological effects on epidermal regeneration.

BACKGROUND
Non-invasive assessment methods such as measurement of the transepidermal water loss (TEWL) allow a continuous follow-up of cutaneous processes with impairment of the epidermal barrier function.


OBJECTIVE
The aim of the trial was to establish an in vivo model for the assessment of drug effects on epidermal regeneration.


METHODS
Twenty healthy volunteers were included in this double-blind randomized trial. After setting four suction blisters on the volar aspect of the forearm, the epidermis was removed to create a standardized subepidermal wound. Thereafter the wounds were treated topically for 6 h daily during 14 days. The following treatments were to be compared: a clobetasol 17-propionate preparation under occlusion, a corticoid-free cream under occlusion, no treatment and occlusion (aluminium chamber), no treatment and no occlusion. Daily measurement of TEWL above the wounds was performed.


RESULTS
The 0.05% clobetasol 17-propionate preparation caused a dramatic delay in TEWL decrease, whereby the untreated unoccluded field showed a continuous decrease over the observed period of 14 days. Occlusion and corticoid-free treatment led to a weak but significant delay of TEWL decrease when compared to the untreated unoccluded test field.


CONCLUSION
This model seems to describe re-epithelialization in a reliable manner and can be used for in vivo assessment of drug effects on migrating and proliferating epithelial cells.