Polyoxyethylene/polyoxypropylen dimethyl ether (EPDME) improves the structure of intercellular lipids in SDS-induced dry skin

The dimethyl ether of an amphiphilic random ethylene oxide/propylene oxide copolymer (EPDME) is useful for the preparation of finely dispersed micro-emulsions. We examined whether EPDME is effective for skin moisturization by means of electron paramagnetic resonance (EPR) studies of ex vivo specimens of stratum corneum (SC) obtained by successive stripping. The values of the order parameter S obtained by EPR measurement indicated that EPDME treatment improved sodium dodecyl sulfate (SDS)-induced disruption of SC lipid structures. This effect appeared to be related to improved hydration of the epidermis, not occlusion by EPDME, since there was no significant change in transepidermal water loss (TEWL).