Moisturization Synergy of hydroxyalkylurea in combination with at least one or more other moisturizing agents.
Publication Date: 2004-Sep-14
The IP.com Prior Art Database
The present invention relates to compositions for personal care products which have a composition containing hydroxyalkylurea in combination with at least one or more other moisturizing agents in a ratio, which synergistically increases moisturization efficacy. Hydroxyalkylurea is derived from urea, wherein the 4 hydrogen radicals on the nitrogen atoms of a urea molecule may be replaced by a C1-4 alkyl or a lower C2-6 hydroxyalkyl group, which may contain from 1 to 5 hydroxyl or hydroxyalkyl groups, providing at least one of the radicals on one of the nitrogen atom of a urea molecule is a hydroxyalkyl or oligohydroxyalkyl group. Preference is given to N-2-hydroxyethylurea with a hydroxyethyl group on one of the nitrogen atom of a urea molecule. Hydroxyalkylurea can also be used alone as a moisturizer for skin and hair. This topic will be the subject of future publications.
The present invention relates to compositions for skin moisturization. Moisturizing agents such as glycerol, urea, and sodium pyrrolidone carboxylic acid (sodium PCA), increase skin moisture levels thereby improving skin elasticity.
Traditionally, improved moisturizing characteristics are obtained by adding higher amounts of one or more moisturizing agents to a formulation. However, cosmetic compositions containing the known moisturizing agents suffer from numerous disadvantages. Some of the main drawbacks of moisturizing agents, such as glycerin, sucrose, and sorbitol include tackiness, greasiness, residue, and gloss on the skin during and after application of a cosmetic product containing these ingredients. These negative attributes create a formidable challenge for cosmetic formulators to develop new products with higher levels of moisturization that meet or exceed consumer sensory expectations. To minimize the negative sensory attributes of glycerin, it is often used in combination with silicones and other aesthetic enhancing agents. In some cases, more expensive moisturizing agents like sodium PCA are used to replace glycerin in the formulation. In addition, other formulation problems can occur including unpleasant odors, unstable pH, and incompatibility with certain raw materials when urea, lactic acid, glycolic acid, maleic acid, acetic acid, and salicylic acid are used to replace glycerin in the formulation. Therefore, the problem to be solved by this invention is to provide a combination of two or more moisturizing agents that delivers moisturization efficacy comparable to or better than the leading benchmark while offering a non-tacky, non-greasy aesthetic in skin care products.
According to the invention, this problem is solved by a composition for the skin which contains a combination of hydroxyalkylurea with at least one or more other moisturizing agents to create a synergistically moisturizing effect. Such moisturizing agents are known in the art and include without limitation: occlusion compounds, humectants, natural moisturizing factors (NMFs), liposomes, natural and vegetable moisturizing agents, alpha and beta hydroxy acids, polymeric moisturizers, and amino acids. As used herein, all acids are intended to include the salts thereof.
Hydroxyalkylureas, as used herein, are derived from urea and are of the general formula:
wherein R1, R2, R3, and R4 each represent, independently of one another, hydrogen, a lower C1-4 alkyl or a lower C2-6 hydroxyalkyl group, which may contain from 1 to 5 hydroxyl or hydroxyalkyl groups, providing that at least one of the radicals R1 – R4 is a hydroxyalkyl or oligohydroxyalkyl group. A particularly useful hydroxyalkylurea is N-2-hydroxyethylurea with the structure
Preferably, the personal care composition contains at least one hydroxyalkylurea, and at least one ammonium salt, and at lea...