Formulation and stability of a novel artificial sebum under conditions of storage and use

Synopsis Materials in contact with liquids on the human skin surface may dissolve and permeate into skin. Release and permeation of chemicals in contact with skin is often estimated in vitro using artificial skin liquids, although sebum lipids are generally not included in these models. The purposes of this research were to develop a representative artificial sebum that contains the appropriate types of lipids at levels that match human values and quantitatively characterize the model to understand its utility for in vitro testing. Artificial sebum that consisted of 10 lipids at proportions that closely resembled human sebum was characterized using thin layer chromatography under a variety of storage and use conditions (dry and liquid, 4°C and 32°C, with and without vitamin E) for 28 days. Levels of sebum constituents maintained in solution and dry at 4°C were stable through the duration of the test period. Levels of all sebum lipids maintained dry at 32°C were stable in the presence of vitamin E; however, squalene oxidized rapidly in the absence of vitamin E. Liquids on the human skin surface consist of sebum and sweat with minor amounts of cellular debris and intercellular lipid from the stratum corneum. The relative importance of each component for release of chemicals from materials in contact with skin will depend upon the type of material (metal, organic, etc.). A model artificial sebum was formulated and characterized to aid researchers in understanding potential release of chemicals from materials in contact with skin and subsequent partitioning and absorption. Résumé les éléments en contact avec les liquides de surface de la peau humaine peuvent se dissoudre et pénétrer dans la peau. La libération et la pénétration de produits chimiques en contact avec la peau sont souvent évalués in vitro en utilisant des liquides cutanés artificiels, bien que les lipides de sébum ne soient généralement pas inclus dans ces modèles. les buts de ce travail étaient de développer un sébum artificiel représentatif contenant les types de lipides appropriés aux concentrations qui correspondent aux valeurs humaines et de caractériser quantitativement ce modèle pour comprendre son utilité lors de test in vitro. Un sébum artificiel consisté de 10 lipides en proportion proches de celles du sébum humain a été caractérisé en utilisant la chromatographie de couche mince dans divers conditions de conservation et d’utilisation (sec et liquide, 4°C et 32°C, avec et sans vitamine