Patent Pick: Avon on Stabilizing Ascorbic Acid

Avon disclosed stable aqueous solutions containing high levels of ascorbic acid and water in a recent patent application. According to the inventors, these compositions have increased stability due to the solution media containing one or more polyhydric alcohols.

See archived: Ingredient Profile; Ascorbic Acid

Ascorbic acid provides antioxidant protection, prevents photo-aging and stimulates collagen production in skin. However, it easily reacts with components in the environment, e.g., oxygen, photons and water, resulting in a color change.

While it is relatively soluble in water (although unstable), its solubility in non-aqueous media is limited such that a solvent (e.g., ethanol) is required to dissolve limited amounts of ascorbic acid. In addition, non-aqueous media often result in non-aesthetically pleasing topical compositions that feel greasy or heavy.

There is thus an unmet need for aesthetically pleasing compositions of stable ascorbic acid; particularly, aqueous compositions with high concentrations of both ascorbic acid and water.

See archived: A Balancing Act; Stabilizing Vitamin C for Skin Benefits

U.S. Patent Application 20220023182Publication date:Jan. 27, 2022Assignee:Avon Products, Inc.

This patent application describes the use of specific polyhydric alcohols to decrease the ascorbic acid to water ratio, resulting in compositions with increased aesthetics, increased ascorbic acid concentration, increased water content, and decreased ascorbic acid instability.

More specifically, the compositions may comprise: a) ascorbic acid and b) one or more polyhydric alcohols wherein the total number of primary hydroxyl groups in all of said polyhydric alcohols is greater than their total number of secondary and tertiary hydroxyl groups; andwherein the weight ratio of ascorbic acid to water is less than 1.

Patent application accessed May 12, 2022.