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

Abstract

The lytic interactions of a series of alkyl glucosides (alkyl chain lengths ranging from C8 to C12) with liposomes formed by a mixture of lipids modeling the stratum corneum (SC) lipid composition were investigated. The surfactant-to-lipid molar ratios (Re) and the normalized bilayer/aqueous phase partition coefficients (K) were determined by monitoring the changes in the static light-scattering (SLS) of the system during solubilization. The fact that the free surfactant concentrations were always similar to their critical micelle concentrations indicates that the liposome solubilization was mainly ruled by the formation of mixed micelles. At the two interaction levels studied (100 and 0% SLS) the nonyl glucoside showed the highest ability to saturate and to solubilize liposomes (lowest Re values), whereas the dodecyl glucoside showed the highest degree of partitioning into liposomes or affinity with these structures (highest K values). Comparison of the data for octyl glucoside with that reported for the interaction of this surfactant 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 saturation and solubilization of liposomes similar to that exhibited in PC vesicles (similar K values).