PERMEABILITY CHANGES IN LIPOSOMES MODELING THE STRATUM CORNEUM COMPOSITION CAUSE BY SURFACTANTS

Abstract

The alterations caused by the surfactants sodiuim dodecyl sulfate (SDS); sodium dodecyl ether sulfate (SDES); Triton X-100 (OP-1OEO) and dodecyl betaine (D-Bet) in the permeability of liposomes formed by a lipid mixture modeling the stratum corneum composition (40%ceramides, 25% cholesterol, 25%i plamitic acid and 10% cholesterylsulfate) were investigated. The SCliposomes/surfactant sublytic interactions were mainly ruled by the action of surfactant monomers in all cases. The OP-10EO showed the highest ability to alter the permeability of bilayers and the highest affinity with these structures, whereas D-Bet showed the lowest tendencies. Although SDS and SDES exhibited sin?ilar activity at 50% CF release (similar Re valiies), the SDES appeared to be more active at 100% CF release, its affinity with bilayers being also increased. Different trends in the evoliition of Re and K were observed when comparing the results obtained with those reported for phosphatidylcholine (PC) liposomes. Thus, wbereas SC liposomes were more resistant to the action of surfactants, the surfactant atlinity with SC bilayers was always greater than that reported for PC ones.