Photostable sunscreen compositions and methods of stabilizing

Abstract

There is provided a photostable and synergistically enhanced topical sunscreen composition. There is further provided a method of enhancing the photostability of a sunscreen active in a topical sunscreen composition. There is further still provided a method of synergistically enhancing the UV absorbance of a sunscreen active in a topical sunscreen composition. The preferred compositions and methods of the present invention use a dibenzoylmethane sunscreen active, a Keempferia galanga extract, and a cosmetically acceptable vehicle.

Description

CROSS-REFERENCE TO A RELATED APPLICATION[0001] This application is a continuation-in-part application of U.S. Ser. No. 10 / 020,642, filed Dec. 14, 2001, which is incorporated herein by reference.[0002] 1. Field of the Invention[0003] The present invention relates to the use of Kaempferia galanga extract to photostabilize a topical sunscreen composition and synergistically enhance the UV absorbancy of a sunscreen composition. More particularly, the present invention relates to a sunscreen composition having a sunscreen active, particularly dibenzoylmethane and / or its derivatives, and an extract of Kaempferia galanga, particularly from the root thereof. The present invention also relates to a method of photostabilizing a sunscreen active in the topical sunscreen composition. The present invention further relates to a method of synergistically enhancing the UV absorbancy of a topical sunscreen composition having at least one sunscreen active.[0004] 2. Description of the Prior Art[0005] ...

AI Technical Summary

Benefits of technology

[0011] It is another object of the present invention to provide a topical sunscreen composition affording enhanced photostability for a dibenzoylmethane sunscreen active.

[0012] It is still another object of the present invention to provide a topical sunscreen composition that exhibits synergistic UV absorbance benefits upon prolonged exposure to sunlight.

[0014] There is also provided a method of enhancing the photostability of a sunscreen active in a topical sunscreen composition. An extract of Kaempferia galanga is introduced into the composition in an amount sufficient to enhance the photostability of the sunscreen active.

[0015] There is also provided a method of synergistically enhancing the UV absorbance of a topical sunscreen composition having a sunscreen active. An extract of Kaempferia galanga is introduced into the composition in an amount sufficient to synergistically enhance UV absorption.

[0027] Although an extract of Kaempferia galanga is known to be useful as a sunscreen active, the effects observed in the present invention upon combination with other sunscreen actives, particularly dibenzoylmethane and / or derivatives thereof, are surprising and unexpected. First, the extract enhances or improves the photostability of the sunscreen active. The enhancement or improvement in photostability of the sunscreen active lengthens the period of time in which photoprotection by the sunscreen composition is provided. Thus, users of sunscreen compositions having the extract can be protected from sunlight for longer periods of time as compared to sunscreen compositions that do not have the extract. Second, the extract synergistically enhances or increases the level of sun protection typically provided by a sunscreen composition. In other words, the level of sunscreen protection afforded by, for example, butylmethoxy dibenzoylmethane and Kaempferia galanga root extract is synergistically greater than the additive effect of these ingredients. This synergistic enhancement permits the use of lower levels of the sunscreen active. Thus, this effect reduces the need for reapplication. A preferred embodiment of the present invention comprises butlylmethoxy dibenzoylmethane, octyl methoxycinnamate and Kaempferia galanga root extract.

Problems solved by technology

A common problem associated with some sunscreen compositions is a tendency of sunscreen actives, including dibenzoylmethane and / or derivatives thereof, to photodegrade over time from exposure to UV (ultraviolet) light.

Second, the extract synergistically enhances or increases the level of sun protection typically provided by a sunscreen composition.

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