Lipid blends exist to provide moisturization to the skin. These act by forming a layer on the skin's surface to regulate water loss. However, according to GlaxoSmithKline (GSK) inventors, there remains a need for compositions with levels of occlusivity that surpass those of existing lipid mixtures. This was the focus of a new invention, disclosed in the described patent application.
Aims of the Invention
In addition to minimizing trans-epidermal water loss (TEWL), the present invention aims to prove a cosmetically elegant composition that is convenient and easy to apply to skin. Further, added care, protect and health benefits were desired. The inventors identified a balanced o/w compositions containing fatty acids and phytosterols, derived, for example, from pumpkin seed oil, shea butter and other sources.
The Literature
Topical composition to repair, restore and protect the skin lipid barrier
U.S. Pat Application 20180303731
Publication date: Oct 25, 2018
Assignee: GlaxoSmithKline Consumer Healthcare Holdings
This invention provides a topical o/w emulsion that moisturizes and protects, repairs or restores the skin lipid barrier. Specifically, the emulsion comprises: a) a discontinuous oil phase; b) a continuous aqueous phase; c) a thickening agent; d) at least one lamellar membrane structure comprising: i) a phospholipid, ii) a fatty alcohol and iii) a fatty acid; e) a pharmaceutically acceptable active agent; and, optionally, f) a dermatologically acceptable excipient.
In one embodiment, said composition has a water vapor transmission rate in use of less than or approx. 75 g·m−2·hr−1, measured in vitro using the modWVTR test methodology.
Lamellar Membrane Structure
Specific to the lamellar membrane structure, the phytosterol, source of phytosterols, cholesterol or cholesterol derivative is present in the structure at about 0.05% to 2% w/w. Phytosterols are natural components of common vegetable oils. Exemplary sources include pumpkin seed oil, shea butter, sesame oil, sunflower seed oil, rice bran oil, avocado wax, etc., and mixtures thereof.
According to the patent application, phytosterols can pass through the skin's surface via the differentiation of skin cells. Accordingly, phytosterols can provide improved care and protect effects. The topical application of phytosterols has been reported to lead to increased skin moisture levels and lipid content. This, in turn, improves the desquamation behavior of the skin and reduces erythema.
Regarding the fatty acid content, this may be derived from a variety of sources, such as an oil or wax. Select examples include pumpkin seed oil, rice bran wax, hempseed oil, grapeseed oil, cottonseed oil, peanut oil, sesame oil and olus (vegetable) oil, including hydrogenated and non-hydrogenated versions thereof, and mixtures thereof.
