Cosmetical Applications
Cosmetics for Skin and Nail Care
Cleansers
Cleansers or foaming washes are facial care products to remove make-up, dead skin cells, grease, dirt and other types of pollutants from the skin surface. All cleansers are based on surfactants – surface active molecules – that dissolve pollutants.
Of particular interest are micellar cleansers. They are oil in water emulsions, where the surfactant is enclosed in micellar vesicles, usually made with phospholipids. Although micellar cleansers very efficiently clean the skin they should only be used after removing dust and solid particles with a regular cleanser.
Toners
Toners are lotions or washes designed to cleanse the skin and shrink the appearance of pores, they are usually applied with a cotton pad. They are milder compared to cleansers, but also moisturize, protect and refresh the skin and usually contain small amounts of alcohol. In acid and adstringent toners phospholipids can be used for protecting the skin against irritation caused by some ingredients.
Pigmentation correctors
Dark spots may be caused by acne, sun damage, or a rash. Such hyper-pigmentations can be attended to with pigmentation correctors containing brightening ingredients such as hydroquinone, retinol and azelaic acid. Some correctors also contain nicotinamide against irregularities of the skin surface. We are however not aware of the use of phospholipids in these products.
Facial masks
Facial masks are used to regenerate and rejuvenate the skin of the face. They are applied on pre-cleaned skin, either in form of a fibre sheet soaked with active ingredients or as a preparation directly painted on the skin. In most masks the eye and mouth area are left uncovered. Masks can also be applied for soothing swollen eyes and tear sacs. A wide range of ingredients is used in masks, many of them anorganic substances (kaolin, silica) and dried plant extracts. Innovative masks already use phospholipids for transferring active ingredients - formulated as liposomal preparations - into the top layer of the skin. Using phospholipids at the same time reduces irritancy caused by slightly aggressive substances.
This is probably the most attractive application for phospholipids. As masks usually remain on the skin for 15 to 20 minutes, a maximum distribution of actives can be obtained.
Exfoliants/Peelings
Exfoliants are used to remove dead cells from the skin surface. The face is “scrubbed” with a blend of abrasive minerals (aluminum oxide, different forms of clay, finely ground volcanic rock), abrasive plant particles (ground seed and nut shells, bamboo bar etc.) and surfactants. These products often are highly irritating and phospholipids are added for soothing and mollifying the skin.
Moisturizers/
Emollients
Moisturizers are used to hydrate the skin and to help retaining its moisture. Emollients make the skin smooth. Both are available as:
- cream (for day or night application)
- gel (transparent mix of polymers and functional ingredients)
- lotion (liquid with functional ingredients)
- oil (herbal or mineral)
- serum (liquid with higher viscosity)
There are two categories of moisturizers:
- Occlusives which form a film on the skin surface, trapping moisture in the upper skin cells.
- Humectants are hygroscopic substances used for keeping the skin humid.
Due to their biomimetic lamellar structure, phospholipids fulfil both roles. They form stable bilayers on the skin surface, in which the outer layer is hydrophilic, providing moisture. The inner layer is hydrophobic, “sealing” the skin surface. It could be demonstrated in experiments that Trans Epidermal Water Loss (TEWL) is significantly lowered in products containing phospholipids.
Bath products
Bath Products are used for bathing, showering and cleaning. They can be found in the form of bath capsules, bath oils, tablets, salts and bubble baths.
Novel oils and other plant derived cosmetic actives can be supplied to the skin in liposomal bath preparations. The ingredients are encapsulated in liposomes, allowing them to pass through the upper layers of the skin. This principle is explained in more detail in the chapter on cosmeceuticals.
Sunscreens
Sunscreens are topically applied products protecting the skin from damaging ultraviolet (UV) radiation, helping to reduce the risk of sunburn, skin cancer and premature skin aging. Ingredients used in sun protection can work by scattering, reflecting or absorbing UV rays. In the EU sunscreens are cosmetic products according to EU regulation No. 1223/2009.
n the USA sunscreens are regulated by the FDA as Over-The-Counter (OTC) drugs and all ingredients must comply with all requirements listed in the FDA's sunscreen monograph.
Phospholipid are used in sunscreens to distribute the active ingredients evenly, providing better protection, longer lasting effect and hydration.