Description
Internal wool lipids (IWLs) are rich in cholesterol, free fatty acids, cholesteryl sulfate, and, mainly, ceramides.
The repairing effect of these lipids structured as liposomes was demonstrated by reinforcing the
skin-barrier integrity and increasing the water-holding capacity when applied onto the skin. This work
was focused on the formation of liposomes with IWLs rich in ceramides, obtained at pilot plant level with
organic solvent extraction by using methanol and acetone. The lipid composition of the two extracts was
quantitatively analyzed. IWL extracts containing different amounts of sterol sulfate were used to form liposomes
at physiologic pH. Vesicle size distribution, polydispersity index, and zeta potential of all liposomes
were determined to characterize them and to study their stability. The results obtained showed that IWL
extract composition, which was different depending on the extraction methodologies used, greatly influences
the characteristics of the liposomes formed. Vesicular size and polydispersity index liposomes were
smaller when the extract composition contained a higher proportion of either free fatty acids or sterol
sulfate. Moreover, liposome stability was improved when some amount of sterol sulfate was added to the
composition of methanol and acetone extracts. This natural mixture with keratinaceous origin could have
a special interest for cosmetic or dermopharmaceutical companies.
; Martí, M. 
