Characterization of lipid model membranes designed for studying impact of ceramide species on drug diffusion and penetration.

The stratum corneum (SC) intercellular lipid matrix plays a crucial role in the skin barrier function. In the present study, lipid model membranes mimicking its phase behavior were prepared and characterized using different analytical techniques (i.a. SAXD, HPTLC, ESEM, confocal Raman imaging, ATR-FTIR spectroscopy) in order to obtain well-standardized model membranes for diffusion and penetration studies. The lipid model membranes should be used in the future for studying the impact of each ceramide species on the diffusion and penetration of drugs. The SAXD study confirmed that the lipids within artificial lipid systems are arranged similarly to the lipids in the human SC. The polarization microscopic and ESEM images showed the homogenous deposition of lipids on the polycarbonate filter. Both the HPTLC and confocal Raman imaging studies proved the homogenous distribution of individual lipid classes within the lipid model membranes. First in vitro diffusion experiments (performed using an ATR-FTIR diffusion cell) of the hydrophilic compound, urea, revealed that the lipid model membrane represents even stronger diffusion barrier than the human SC.