Influence of the hydrophobic tail of alkyl glucosides on their ability to solubilize stratum corneum lipid liposomes

The lytic interactions of a series of alkyl glucosides (alkyl chain lengths ranging from C-8 to C-12) with liposomes formed by a mixture of lipids mod eling the stratum corneum (SC) lipid composition were investigated. The sur factant-to-lipid molar ratios (Re) and the normalized bilayer/aqueous phase partition coefficients (K) were determined by monitoring the changes in th e static light-scattering (SLS) of the system during solubilization. The fa ct that the free surfactant concentrations were always similar to their cri tical micelle concentrations indicates that the liposome solubilization was mainly ruled by the formation of mixed micelles. At the two interaction le vels studied (100 and 0% SLS) the nonyl glucoside showed the highest abilit y to saturate and to solubilize liposomes (lowest Re values), whereas the d odecyl glucoside showed the highest degree of partitioning into liposomes o r affinity with these structures (highest K values). Comparison of the data for octyl glucoside with that reported for the interaction of this surfact ant with phosphatidylcholine (PC) liposomes shows that whereas the SC lipid liposomes were more resistant to the action of this surfactant (higher Re values), its degree of partitioning into SC bilayers was both in the satura tion and solubilization of liposomes similar to that exhibited in PC vesicl es (similar K values).