Liposomes are vesicular structures with an aqueous core surrounded by a hydrophobic lipid
bilayer, created by the extrusion of phospholipids. Phospholipids are GRAS (generally
recognised as safe) ingredients, therefore minimising the potential for adverse effects.
Solutes, such as drugs, in the core cannot pass through the hydrophobic bilayer however
hydrophobic molecules can be absorbed into the bilayer, enabling the liposome to carry both
hydrophilic and hydrophobic molecules. The lipid bilayer of liposomes can fuse with other
bilayers such as the cell membrane, which promotes release of its contents, making them
useful for drug delivery and cosmetic delivery applications. Liposomes can vary in size, from
15 nm up to several μm and can have either a single layer (unilamellar) or multilayer
(multilamellar) structure. Liposomes that have vesicles in the range of nanometres are also
called nanoliposomes. A new type of liposomes called transferosomes, which are more elastic
than liposomes and have improved efficiency, have been developed
in the range of 200-300 nm can penetrate the skin with improved efficiency than liposomes
These self assembled lipid droplets with elastic bilayers are capable of spontaneous
penetration of the stratum corneum through intracellular or transcellular routes and have
potential applications in cosmetics and drug delivery
The first liposomal cosmetic product to appear on the market was the anti-ageing cream
‘Capture’ launched by Dior in 1986. Since then several hundreds of products which utilise
liposomal delivery capabilities have been introduced into the market, however only some
contain liposomes in the nanoscale. Liposomes are unstable due to their susceptibility to
oxidation and the breakdown of liposomal structure. However, formulations have been
developed that are more stable by optimising the storage conditions and adding chelators and
anti-oxidants
tissue from freezing damage)
One of the reasons for the widespread use of liposomes in the cosmetic industry is their ease of
preparation and the ability to improve the absorption of active ingredients by skin. The ease
of scale up made the widespread use of liposomes in cosmetic applications a reality.
Liposomes have been formed that facilitate the continuous supply of agents into the cells over
a sustained period of time, making them an ideal candidate for the delivery of vitamins and
other molecules to regenerate the epidermis
vitamins A and E) and antioxidants (e.g. CoQ10, lycopene and carotenoids) have been
incorporated into liposomal membranes to increase their delivery
encapsulation capability of liposomes by adding emulsifiers have been proposed. However, this
compromises the barrier integrity and the lipids are easily removed by washing.
Phosphatidylcholine, one of the main ingredients of liposomes, has been widely used in skin
care products and shampoos due to its softening and conditioning properties. Liposomes have
proved to be a convenient way to deliver phosphatidylcholine.
Liposomes have also been used in the treatment of hair loss. Minoxidil, a vasodilator, is in the
active ingredient in products like Regaine
loss. It is formulated in liposomes to improve the flux of contents through the skin
sulphate in propylene glycol (PG)-coated liposomes is also marketed as Nanominox-MS
(
2. Transferosomes with sizes3.4.5. It is also possible to add cryoprotectants (substances to protect biologicali to liposomes to store them in frozen or lyophilized form.6. Several active ingredients, biomolecules (e.g.7. Efforts to improve the(www.regaine.co.uk) that claim to prevent or slow hair8. Minoxidilhttp://www.sinere.com/nanominox-ms_en.html).i
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