Natural or Synthetic Emollients? Physicochemical Properties of Body Oils in Relation to Selected Parameters of Epidermal Barrier Function

Emollients are valued ingredients of many cosmetic products and medical devices used to support the treatment and prevention of many skin diseases. Despite the fact that they are one of the oldest cosmetic ingredients, raw materials as well as new recipe solutions are constantly being sought, the main goal of which is to obtain products with the most favorable physicochemical properties while improving the hydration of the stratum corneum and softening and smoothing the skin. It should be noted that there are few scientific articles on the effect of emollients on the physicochemical and usable properties of emollient preparations of the body-oils type. The obtained formulations were subjected to physicochemical tests (dynamic viscosity, surface tension, contact angle, and color evaluation), and the degree of skin hydration and lubrication after application of the developed cosmetic oils was evaluated. Cosmetic oils based on natural emollients were characterized by weaker spreading abilities, which was confirmed by their higher viscosity, surface tension, and contact-angle results relative to those obtained for cosmetic oils based on synthetic emollients. In addition, it was found that the use of both groups of cosmetic oils based on natural and synthetic emollients leads to an increase in the degree of hydration of the skin and an increase in its oiliness. However, a higher increase in the degree of hydration and a lower decrease in the level of skin lubrication are observed after the application of body oils based on natural emollients.