Non-invasive in vivo methods to measure lipidic formulae efficacy at the skin surface: advantages and limits

摘要

Lipids are major ingredients in cosmetics and play an essential role in cosmetics ability to improve skin, hair, nail and mucuous membranes aspect, sensory qualities and function, either by interacting with skin components, enhancing active ingredient release or by spreading and forming a protective layer on its surface. Measuring lipids efficacy to the skin is possible through a wide range of non-invasive clinical and instrumental methods. Measurements of sebum, temperature, hydration, transepidermal water loss, skin surface topography, skin firmness, elasticity, color enable to assess the lipids ability to protect the skin, hair and mucuous membrane (from pollution, cold, chemical aggression, dehydration), restore stratum corneum barrier function, improve cutaneous visco-elastic properties and surface characteristics, enhance skin or hair sensory qualities (softness, smoothness) or look (radiance, shine), nourish dry skins and mucuous membranes or help sooth sensitive ones. We explored the advantages and limits of these methods.