MXPA01002413A - Process and composition for enhancing the action of vitamin a on the cellular activity of an individual, and use of vitamin c - Google Patents

Abstract

The present invention refers to a process, a composition and the use of Vitamin C for enhancing the action of Vitamin A on the cellular activity of an individual. According to the invention, the association of Vitamin C to Vitamin A will be applied to said individual at a weight ratio ranging from 1:1 to about 10:1.

Description

PROCESS AND COMPOSITION FOR IMPROVING THE ACTION OF VITAMIN A ON THE CELLULAR ACTIVITY OF THE INDIVIDUAL, AND USE OF VITAMIN C Field of the Invention The present invention relates to a process for improving the effects of Vitamin A used in cosmetic compositions for improving the cellular activity of an individual.

Background of the Invention The compound known generically as Vitamin A comprises retinol and its derivatives, also known as retinoids, in addition to its acid or aldehyde form, respectively retinoic acid and retinal. The retinoic acid has application in the pharmaceutical and cosmetic industries being, however, prohibited in several countries for cosmetic use due to the adverse effects of irritability that it can cause. The effects of pharmaceutical application of retinoic acid can be found in the article "Relationship between structure and activity of retinoids", published by Nature, Volume 236, pages 110-113, September 9, 1996. In the cosmetic area Vitamin It is usually used in the form of retinol or some of its retinoids Ref: 127740 such as retinyl palmitate, and the use of retinol causes various biological activities, many of which are highly desirable in cosmetic compositions, particularly those which are intended to improve general conditions of the skin of the individual subjected to the topical use thereof. The results achieved by the topical use of Vitamin A are described in passages contained on pages 82-119 of the article entitled "Vitamin A Complex", written by Wade Cheng, PhD and Shirley DePetris and published by Skin Inc., March / April 1998. In addition, the regulation and balance of epidermal cell growth through total collagen synthesis, among others, such as the retention of water in the skin, are also known effects resulting from the use of Vitamin A in its pure form , called Retinol. A problem resulting from Vitamin A, either in pure form or with a derivative, is that, on the one hand, it promotes the effects of increasing cellular activity at the level of the dermis and epidermis, accelerating the process of proliferation and differentiation of keratinocytes. and reorganization of the dermis fibers (collagen and elastin). But on the other hand it must be administered at low doses due to its toxicity. This fact limits the use of Vitamin A and its derivatives at lower contents or requires the use of other means that are able to minimize the discomfort of skin irritation. In fact, the use of retinol at low content is very common, as shown by several studies, such as the one conducted by the Experimental Dermatology Clinic of Hamburg in Germany, which describe tests with low contents of Retinol (0.034%) for men and women between 22 and 34 years old and who show that such concentration of retinol could reduce the amount and depth of wrinkles. Therefore, this study shows generically the effect of reducing wrinkles under the use of low retinol contents. On the other hand, what has been observed is that, although the low concentrations of retinol cause little or no irritation, the results on the skin may remain below the desired levels for the standards or current levels of the consumers in view of the small amount of retinol incorporated in the cosmetic composition and available for its biological action. In this regard, there have been attempts to obtain a Vitamin A composition that have an effective action and do not cause adverse effects, for example skin irritation. As an example, documents US 5516793 and US 5703122 in the name of Avon Products, Inc., are incorporated herein by reference in the prior art. These documents describe ^^^ ^ A ^^ n a generic association of amounts ranging from 0.5 to 25% by weight of Vitamin C with several irritating active principles, among which Vitamin A is included. This association, however, has the exclusive purpose of reducing the skin irritation caused by Vitamin A. Therefore, an objective of the present invention is to provide an alternative for the use of Vitamin A at such concentrations that allow an increase in its properties that are beneficial for the skin, without Present the problems mentioned above.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a process for improving the action of Vitamin A on the cellular activity of an individual, comprising the association of Vitamin C with Vitamin A, which will be applied to reference individual to a ratio in the weight that fluctuates from about 1: 1 to about 10: 1. In another aspect, the invention relates to a composition for improving the action of Vitamin A on the cellular activity of an individual, comprising Vitamin C in association with Vitamin A in a weight ratio in the range of about 1: 1 to 10: 1 The invention also relates to the use of Vitamin C to improve the action of Vitamin A on the cellular activity of the individual.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a graph showing the increase in cellular activity of a skin reconstituted by the synergistic effect of an association of Vitamin C with Vitamin A according to the invention compared to the cellular activity of a reconstituted skin treated only with pure Vitamin A. Figure 2 shows the synergistic effect on recovery and the increase in cellular activity in the reconstituted skin treated with Vitamin A associated with Vitamin C when subjected to ultraviolet radiation.

DETAILED DESCRIPTION OF THE INVENTION After detailed studies the inventors have found that the association of Vitamin C added to compositions containing Vitamin A at a weight ratio ranging from about 1: 1 to about 10: 1, preferably about 1: 1 to about 5: 1, and more preferably from about 1: 1 to about 2: 1, provides a surprising increase in the effects of Vitamin A on cellular activity in an individual. The "Vitamin C" useful for the present invention comprises Vitamin C in its pure form or its derivatives, namely L-ascorbic acid in its molecular form as well as its salts and esters such as ascorbyl phosphate. As used herein, the term "an increase in cellular activity" means the occurrence of a benefit obtained by the increase or improvement of at least one of the situations selected from the maintenance of the cell condition, cell proliferation and metabolic activity especially in the skin cells. Tests carried out on reconstituted skin show that a treatment of the skin in vi tro with the association of Vitamin C with Vitamin A according to the present invention promotes an unexpected synergistic increase in cellular activity of 100% compared to cellular activity observed in the same skin treated exclusively with pure Vitamin A or retinol (Figure 1). In the same surprising way, it has been noted that the association of Vitamin C with Vitamin A promotes the reconstitution, recovery and increase of cellular activity of the skin, even when the individual is subjected to ultraviolet radiation, which is recognized to cause effects harmful to the skin and its cells. Tests carried out in this regard show synergistic effect of reconstitution and increase of cellular activity of 5% on reconstituted skin treated with Vitamin A associated with Vitamin C when subjected to ultraviolet radiation (Figure 2). The association of Vitamin C with Vitamin A according to the present invention can be carried out at the time of application of those compounds to the individual, but it can also be advantageously formulated as a cosmetic composition containing the two vitamins at a ratio of fluctuating weight from about 1: 1 to about 10: 1, preferably from about 1: 1 to about 5: 1, and more preferably from about 1: 2 to about 2: 1 from Vitamin C to Vitamin A. According to a preferred embodiment of the invention, the cosmetic composition comprises, by weight, from about 0.01 to about 0.9% of Vitamin C and from about 0.008 to about 0.20% of Vitamin A, based on the total weight of the composition. Even more preferably, the composition contains from about 0.02 to about 0.8% by weight of Vitamin C and from about 0.009 to about 0.16% by weight of Vitamin A, and most preferably the composition contains 0.02% by weight of Vitamin C and of », ______ - *. "+" *** approximately 0.009 to approximately 0.02% by weight of Vitamin A, all percentages based on the total weight of the composition. It should be noted that, even at very low concentrations, the Vitamin A associated with Vitamin C as defined in the present invention achieves the desired effects of increasing cellular activity. Cosmetic compositions containing vitamin A and vitamin C in the proportions cited above may also contain other suitable additives and formulation aids, such as antioxidants to combat free radicals. Among the useful antioxidants, Vitamin E can be mentioned, both in its pure form represented by dl-a-tocopherol, and derivatives such as dil-a-tocopherol or 2,6-di-tert-butyl-p-cresol (B HT) . The introduction of Vitamins C, A and E in microspheres increases their action and makes it possible for them to reach the deepest layers of the skin with greater, or even total, integrity, without degenerating the product on the way between the application area and the place of action. In a particularly preferred form, the cosmetic compositions according to the present invention are formulated in such a way that their components are contained in organic vectors such as microspheres and, I..AJ / .... ". **",: more particularly, in microspheres or microcapsules containing biologically active material between ("Talospheres") such as those defined in US Pat. No. 5,395,620, or in the application of Brazilian patent Pl 9706994-7, filed in the name of this same applicant. The composition as described above may contain a plurality of microspheres, in dispersed form, containing vitamin A and, for example, an antioxidant such as Vitamin E, inserted into a first group of microspheres, and Vitamin C inserted into a second group of microspheres. A particularly preferred composition comprises a first group of microspheres containing Vitamin A at an average concentration of 0.014% and Vitamin E at an average concentration of 0.0005%, and a second group of microspheres containing 0.02% by weight of Vitamin C. advantageous, in association with the groups of microspheres mentioned above, such composition may contain, in addition to Vitamin A and Vitamin E, cosmetic compounds selected from the group consisting of skin structures, and preferably complexes of squalene and sphingolipid, micronutrients of the skin , preferably extract of algae, sensory agents, for example, humectants such as glycerin and hydroxylprolisyl C, emollients such as butylene glycol and cetyl lactate and silicones such as cyclomethicone, sun protection factors such as Parsol 1789 and Eusolex 6300, emulsifiers, preferably Carbopol 1342 associated with tri ethanolamine and soy lecithin, thickeners, preferably xanthan gum, sequestrants, preferably EDTA, antioxidants such as BHT and dl-a-tocopherol, fragrances, preservatives, water and mixtures thereof. In a particular embodiment of the present invention, the composition containing Vitamin A and Vitamin C may be in the form of an emulsion and, in this case, the Vitamin C preferably used is L-ascorbic acid stabilized by compounds that form hydrogen bonds. Such stabilization processes of L-ascorbic acid are described in the applications PI 9704418 and PI 9704728-7, also filed by this same applicant. As an illustrative example of another possible embodiment of the present invention, the composition is formulated as a gel in which the weight ratio of Vitamin C to Vitamin A is advantageously about 5: 1, Vitamin C being present preferably in amounts of about 0.75-r and Vitamin C being present in amounts of about 0.75% and Vitamin C being present in amounts of about 0.16% by weight, based on the total weight of the composition. This gel composition lili - ^ Mgb may also contain thickeners such as ascarbopol, fragrances, preservatives and water. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture to which it refers.

Claims (6)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property. A composition for improving the action of vitamin A on the cellular activity of an individual, characterized in that it contains a plurality of dispersed microspheres, the plurality of microspheres comprise Vitamin A and an antioxidant, preferably Vitamin E, inserted in a first group of microspheres, and Vitamin C inserted in a second group of microspheres.
2. 2. The composition according to claim 1, characterized in that Vitamin C is present in a composition of approximately 0.02% by weight, and Vitamin A is present at a concentration of approximately 0.009% to 0.02% by weight, based on to the total weight of the composition.
3. 3. The composition according to claim 2, characterized in that Vitamin C is contained in the second group of microspheres at a concentration of 0.02%. . The composition according to claim 3, characterized in that it contains a first group of microspheres containing Vitamin A at an average concentration of approximately 0.014% by weight, based on the total weight of the composition. The composition according to claim 4, characterized in that it contains a first group of microspheres containing Vitamin A at an average concentration of 0.014% and Vitamin E at an average concentration of 0.0005% by weight, and cosmetic compounds selected from the group that consists of cutaneous structures, preferably squalene and sphingolipid complexes, micronutrients of the skin, preferably yeast extract, sensory agents, preferably humectants such as glycerin and hydroxyprolisil C, emollients such as butylene glycol and lactate cetyl and silicones such as cyclomethicone, sun protection factors such as Parsol 1789 and Eusolex 6300, emulsifiers, preferably Carbopol 1342 associated with tpetanolamine any thickeners of soy lecithin, preferably xanthan gum; sequestrants, preferably EDTA, antioxidants such as BHT and d 1-a-tocopherol, fragrances, preservatives, water and mixtures thereof. The composition according to claim 1, characterized in that it comprises Vitamin C in association with Vitamin A in a weight ratio ranging from approximately 1: 1 to approximately 10: 1 from Vitamin C to Vitamin A. ri ¿¿Arfá * '"" • - • "» • »* - - -" - * «» ^ - .. »-..-. - tfo »f t, .--.