Two novel techniques for the evaluation of barrier creams

There are few methods for assessment of the efficacy of barrier cream preparations that can be used in vivo. This paper describes two such tests. The first relies on the ability of a topically applied barrier preparation to prevent dyes from reaching the stratum corneum from filter paper discs in small aluminium chambers. The amount of dye crossing the barrier cream and reaching the stratum corneum was assessed by removing the superficial layers by skin surface biopsy and eluting out the dye. The second test employed dilutions of sodium hydroxide as indicator reagents. The degree to which these solutions penetrated the barrier on the skin was assessed by measuring the skin blood-flow using the laser Doppler method. It was concluded that both methods could be usefully employed to assess the degree of efficacy of barrier cream preparations.