Stratum corneum interactions with liposomes

Blume, A., Jansen, M., Ghyczy, M. etal. Interaction of phospholipid liposomes with hpid model mixtures for stratum corneum lipids. Int. J. Pharm. 1993 99 219-28. 

The present daily approach to skin care formulations is based on an assumed relation between the original composition and the final activity of the product. So a significant number of authors have tied to relate the size of liposomes in a solution to the final action of an active substance. The results [48,49] have given ample proof that such a relation does not exist. The reason for this lack of success is obvious. Within 25 min after application, 90-95% of the water in a formulation operates, and the new structures appearing during this process cannot a priori be related to the original structures. The biological activity of the formulation depends on the final structure and its interaction with the stratum corneum structural units. Hence, the activity of the formulation depends on the structures found in the water-poor parts of the system as shown in Fig. 5. 

Schaller, M. and Korting, H. C., Interaction of liposomes with human skin the role of the stratum corneum, Adv. Drug Delivery Rev., 18, 303-309 (1996). 

With differential scanning calorimetry, a distinct effect of the cubic GMO particles on the phase transitions of human stratum comeum was observed in contrast to the situation with the other types of lipid nanoparticles (Fig. 10.5). Moreover, cubosomes caused an interaction with "skin liposomes" (having a similar lipid composition as the stratum corneum lipids) in fluorescence assays indicating their fusogenic potential. An interaction of GMO with the stratum corneum lipids was thus proposed as the cause of enhanced permeation from cubosomes. An interaction of the GMO nanoparticles with lipid structures of the skin may also explain the much higher fluorescence that was observed upon incubation of human epidermis with fluorescently labeled cubosomes compared to solid lipid nanoparticles (Fig. 10.6). 

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