Résumé : |
The purpose of cosmetic products is to enhance or correct the appearance of the skin (decorative) and to preserve skin and hair integrity (care). In both of these application areas, oils and fats (O&F) are compulsory ingredients whose properties rank from acting to preserve and restore the integrity of the stratum corneum, to building the galenic or texture of a formula.
By definition, O&F are organic compounds, which exhibit various chemical structures, are anhydrous, not soluble in water, and soluble in non polar organic solvents. They naturally occur in nature in the animal or vegetable kingdom, under a soid (fat) orliquid (oil) state.
In the cosmetic industry, we could extend this definition to two additional origins : mineral (e.g. components derived from petroleum) and synthetic (such as esters or some hydrocarbon oils).
In order to review the major natural oils and fats used into cosmetics, to defins groups according to their melting point would be an arbitrary but easy approach. In fact, this physical parameter would allow drawing three big families, based on the aspect of the component at room temperature : oils for liquid, waxes for solid, and 'in between' : soft solid such as butters. |