Stabilization of ascorbic acid, ascorbic acid derivatives and/or extracts containing ascorbic acid for topical use

Abstract

A stable composition is provided to treat and / or prevent photo-aged skin and related skin disorders such as sunburn, wrinkles, poor skin tone and skin discoloration by topically applying to the skin the treatment composition containing an effective amount of a compound such as ascorbic acid, derivatives of ascorbic acid and / or extracts containing ascorbic acid, in a pharmaceutically acceptable vehicle containing a substantially anhydrous base having no water added. The anhydrous base stabilizes the compound, so that the compound remains effective for an effective period of time, even in the presence of exposure to water.

Description

FIELD OF THE INVENTIONThe present invention is directed to a composition for stabilizing ascorbic acid, ascorbic acid derivatives and / or extracts containing ascorbic acid, in a stable delivery system for topical application to the skin. The composition prevents premature aging of the skin of humans, or may be used to treat photo-aged skin and resultant wrinkles and other sequelae.BACKGROUND OF THE INVENTIONTreatment of photo-aged skin and resultant wrinkles and other sequelae with ascorbic acid and related derivatives has been discussed in the prior art. Among the most common treatment regimen is a topical application of ascorbic acid to affected areas of the skin in lotions, creams and other delivery vehicles, such as discussed in U.S. Pat. No. 5,140,043 of Darr et al for stable ascorbic acid compositions.In Darr '043, it is noted that L-ascorbic acid prevents ultraviolet (UV) damage to the skin. In the discussion of the background art therein. Darr '043 states that ascorbic acid, ...

AI Technical Summary

Benefits of technology

It is therefore an object of the present invention to provide a stable composition and pharmaceutical delivery system for ascorbic acid, ascorbic acid derivatives and / or extracts containing ascorbic acid as effective treatments for photo-aged skin and related skin disorders.

It is yet another object to provide a topical preparation of ascorbic acid, ascorbic acid derivatives and / or extracts containing ascorbic acid for more effective treatment of photo-aged skin and related skin disorders.

It is yet a further object to provide ascorbic acid, ascorbic acid derivatives and / or extracts containing ascorbic acid, in a composition wherein the ascorbic acid, ascorbic acid derivatives and / or extracts containing ascorbic acid remain effective for an extended period of time.

Problems solved by technology

Free radicals from ultraviolet light (UV) are known to increase with air pollution in areas of concentrated populations, thereby magnifying the problem.

The free radicals are destructive in that the free radicals hydrolyse elastin fibers in the skin and desynthesize collagen in the lower dermal layers of the skin, thereby causing skin wrinkles and other damaging skin conditions.

However, ascorbic acid, such as Vitamin C, is difficult to stabilize for any significant period of time in pharmaceutical vehicles for topical delivery to the skin.

Ascorbic acid loses potency and discolors easily in most delivery vehicles.

Furthermore, ascorbic acid hydrolyzes when exposed to water.

Moreover, as noted in Darr '043, ascorbic acid washes off easily when exposed to water, so that topical application at a sun-lit beach is generally futile, since swimming washes away the topically applied ascorbic acid.

Furthermore, in the past, ascorbic acid has been administered in high dosages to the skin, and has to be made every day because of its instability, thus increasing cost of its use.

However, the disadvantage of the delivery vehicle in Darr '043 is that it is water-based, and therefore the ascorbic acid is still inherently unstable.

Therefore, a loss in potency of the magnitude as shown in Darr '043 in such a short time span, raises serious questions as to the usefulness of the stability data obtained in predicted the potency of L-ascorbic acid at the time the consumer is able to use the product.

Therefore, the response of the ascorbic acid in the epidermals and dermis of the skin is not very effective, because of the presence of substantial amounts of water, which contribute to destabilization of the ascorbic acid.