HUMAN CUTANEOUS RESPONSE TO A MIXED SURFACTANT SYSTEM - ROLE OF SOLUTION PHENOMENA IN CONTROLLING SURFACTANT IRRITATION

Exposure of the skin to surfactant-based products can result in irritation. To control this effect researchers are probing mechanisms of surfactant action. In vitro studies show that mixing surfactants often results in less denatura- tion (swelling) of stratum corneum. We have explored the in vivo human irritation response (using a 21-day cumulative irritation test) to two of these surfactants - sodium lauryl sulfate (SLS) and (C12-C14) alkyl, 7-ethoxy sulfate (AEOS- 7EO). Results demonstrate that addition of AEOS-7EO to a constant dose of SLS results in a significant reduction in erythema, hence producing a milder system. The reason for the synergism is unclear, but may relate to experimentally determined alterations in the micellar solution properties of the SLS upon addition of AEOS-7EO. © 1990 S. Karger AG, Basel.