Thermal and spectroscopic characterization of interactions between 2-nonyl-1,3-dioxolane and stratum corneum components

The effect of 2-nonyl-1,3-dioxolane (SEPA(TM)) on the structure of human stratum corneum was investigated by FT-IR spectroscopy at variable temperature, differential scanning calorimetry and scanning electron microscopy. A significant influence of SEPA(TM) treatment on position and intensity of IR absorption bands and DSC thermal transitions of SC lipids was detected. An appreciable loosening of SC cell packing was also observed by SEM analysis. These modifications are reversed after SEPA(TM) is removed from the site of application. The results clearly demonstrate that SEPA(TM) is able to modify the structure of the lipid matrix in which corneocytes are embedded, thus suggesting a possible use of SEPA(TM) to increase the permeability of the stratum corneum to lipophilic drugs.