and many workers have tested this hypothesis. Foldvari et al. (1990) applied DPPC, CH (2:1) liposomes loaded with
an electron dense marker to guinea pigs.
Electron micrography showed the presence of intact liposomes in the dermis.
The authors proposed that liposomes carrying the drug can penetrate the epidermis.
Nano-aggregates were better than a traditional gel in the treatment of eczema but not for psoriasis (Korting et al., 1990).
It was thus concluded that vesicles can penetrate diseased skin with its ruptured SC (as in eczema) but cannot invade skin with hyperkeratosis, as in psoriasis.
Subsequently, fluormicrographic studies showed that intact small unilamellar vesicles (SUVs) of PC and CH penetrated no deeper than the SC (Lasch et al., 1991).