This invention relates to a process for obtaining a polysaccharide-rich active ingredient of high molecular weight that is derived from oat fibers and/or bran and/or seeds, having an immediate anti-wrinkle effect and/or immediate tensor effect on the skin.
The invention also relates to the active ingredient that can be obtained by this process, its uses, and the related cosmetic compositions.
To appear younger, many people want to tone up their skin and attenuate the directly visible, unsightly physical changes that are linked to cutaneous aging.
The aging of the skin results from various alterations caused by factors that are both genetic and environmental. It manifests itself in particular by the loss of mechanical strength and viscoelastic and lifting properties of the dermis. The skin then has the tendency to stretch under the influence of its own weight, thus causing surface deformations, and the formation of wrinkles and unsightly folds. The epidermis also loses its thickness, and the cutaneous microrelief is modified.
To fight against this phenomenon, cosmetic active ingredients are therefore sought that make it possible both to lift and smooth the cutaneous microrelief, and to improve the viscoelastic properties of the skin at the same time.
To date, to meet their lifting needs, the formulators have had at their disposal two types of substances:
Also, the purpose of this invention is another molecular means to eliminate the drawbacks of the prior art by proposing a process for obtaining an active ingredient with an immediate tensor effect that is effective, soluble and stable in water, of plant origin, and that limits the protein content as much as possible.
To this end, the invention has as its object a process for obtaining an active ingredient with an immediate anti-wrinkle effect and/or immediate tensor effect on the skin, characterized in that it consists in extracting and purifying polysaccharides of high molecular weight from oat bran and/or fibers and/or seeds and in solubilizing and stabilizing these polysaccharides in water.
The active ingredient according to the invention can be obtained from simple oat fibers and/or from oat bran, residue of the oat grounds obtained from the pericarp of seeds that, in addition to fibers, contains proteins, mineral salts, and vitamins, and/or from oat seeds.
Advantageously, the active ingredient that is obtained, polysaccharide-rich and of a high molecular weight, produces a sensation of stretched and toned skin and has an immediate tensor effect that is characterized by a smoothing of the cutaneous microrelief and an improvement in the mechanical properties of the skin, thus an immediate anti-wrinkle effect.
This invention is now described in detail by using non-limiting examples of compositions, as well as test results grouped in tables.
The process according to this invention comprises at least two essential stages:
According to an embodiment of the invention, to facilitate the solubilization of polysaccharides, at least one adjuvant for solubilization in the basic solution, preferably a salt, a polyphosphate and/or an oxidizer, is added.
The concentration of alkaline agent of the basic solution for solubilization can be adjusted so that the physical properties of the polysaccharides are not altered by simple sugars during hydrolysis.
Preferably, the process according to this invention also comprises a deproteinization stage.
According to a preferred embodiment, the process according to the invention comprises the series of the following stages:
Advantageously, the process according to the invention allows the preservation of native polysaccharides that are derived from oat bran and/or fibers and/or seeds, while facilitating the industrial feasibility of the active ingredient.
II/Characterization of the Active Ingredient that is Obtained According to the Invention from Oats
The level of dry material is measured by running a sample with a given initial weight through the oven at 105° C. until a constant weight is obtained.
The level of dry material is between 20 and 200 g/l, more particularly between 60 and 110 g/l.
The pH that is measured by the potentiometric method at ambient temperature leads to values of between 4 and 8, more particularly between 5 and 6.
The method of DUBOIS (DUBOIS, M. & al. [1956], Analytical Chemistry, 28, No. 3, pp. 350-356) is used.
In the presence of concentrated sulfuric acid and phenol, the reducing sugars provide a yellow-orangey compound.
Starting from a standard range, it is possible to determine the level of total sugars of a sample.
The level of total sugars of the active ingredient according to this invention is 19 to 190 μl, preferably 57 to 105 μl.
The ratio of the total sugars to the level of dry material for the active ingredient according to this invention is greater than 50%, preferably greater than 80%.
The mean polymerization degree of polysaccharides is determined by the ratio of the level of total sugars to the level of reducing sugars.
The metering of reducing sugars is carried out as follows:
The mean polymerization degree of the polysaccharides of the active ingredient according to this invention is greater than 40, preferably greater than 60.
The distribution by size of the polysaccharides that are obtained by the implementation of the process according to the invention is carried out by studying the chromatograms.
The polysaccharides that are obtained by the implementation of the process according to the invention are polysaccharides of high molecular weight. They have a polysaccharide size of between 30 and 2,000 kDa. Preferably, 50% of the polysaccharide fraction has a size of between 70 and 700 kDa.
III/Evaluation of the Effect of the Active Ingredient that is Obtained According to the Invention from Oats
III-1/Evaluation of the Tensor Effect by Cutometer
This study has as its objective to evaluate the tensor effect of an active ingredient that is obtained according to the invention from oat bran.
The study is performed on volunteers using a Cutometer.
A Cutometer is a device that is equipped with a probe that is applied to the skin in which a constant depression is maintained. The depth of penetration of the skin in the probe is measured under the intake effect.
When subjected to these depressions, the skin becomes tired more or less quickly and the response times as well as the measured amplitudes make it possible to determine the parameters, in particular:
If Ue decreases, the skin is less flexible and therefore more stretched.
If Uf decreases, the skin is less extensible, and therefore also more stretched.
The operating protocol is as follows:
As reference results, the BSA (bovine serum albumin) metered at 4% is used.
The results that are obtained for the active ingredient that is derived from oat bran according to the invention are expressed relative to the placebo in the table below:
It is noted that the active ingredient according to the invention reduces the elastic component and the extensibility of the skin: it has an immediate tensor effect on the skin.
III-2/Evaluation of the Tensor Effect in Sensory Analysis
The objective of this study is to quantify in vivo the tensor effectiveness of an active ingredient according to the invention, obtained from oat bran, formulated at 10% of counter-placebo gel.
The sensory evaluation test consists in having a panel of experts make a blind evaluation of the tightening and non-sticky sensation. The study is performed on 15 healthy volunteers at the level of the eye and the crow's-feet.
The operating protocol is as follows:
The analysis of the scales is carried out by totaling the scores over three cycles.
The various gels are tested randomly over several days (one gel per day).
The results that are obtained are presented in the table below:
It is noted that after a single application, the experts identify the active ingredient according to the invention as tightening and non-sticky, and score it at an effectiveness of 13.6, which is higher than that of BSA metered at 10%.
III-3/Evaluation of the Immediate Anti-Wrinkle Effect
The object of this study is to quantify the immediate anti-wrinkle effectiveness of an active ingredient according to the invention, obtained from oat seeds, formulated at 4% in counter-placebo emulsion.
The study is performed on healthy female volunteers.
Anti-wrinkle effectiveness is measured by means of silicone imprints made in the crow's-feet of volunteers.
The analysis of these imprints using a profilometer equipped with an image analyzer makes it possible to obtain three parameters: the number of wrinkles, the total wrinkled surface area, and the total length of the wrinkles.
The study is performed according to the following protocol.
At T0, two symmetrical cutaneous zones are identified at the crow's-feet—one intended to be treated by placebo, the other by the active ingredient—and imprints are made of these two zones.
After the imprints are made, the placebo and the active ingredient according to the invention, derived from oat seeds and formulated at 4%, are applied to the defined zones.
At T 2 hours, the imprints are made on the two zones that are being studied.
The results that are obtained for the active ingredient according to the invention, derived from the oat seeds, are expressed in the table below by percentage relative to those obtained for the placebo:
It is noted that after two hours, in comparison to the placebo, the active ingredient according to the invention that is formulated at 4% reduces the number of wrinkles, the total wrinkled surface area, and the total length of the wrinkles at the same time. It therefore has an immediate anti-wrinkle effect.
III-4/Evaluation of the Tensor Effect in Sensory Analysis
The objective of this study is to quantify in vivo the tensor effectiveness of the active ingredient according to the invention, obtained from oat seeds, formulated at 4% of counter-placebo gel.
The sensory evaluation test consists in having a panel of experts make a blind evaluation of the tightening and non-sticky sensation, formed with this tightening sensation. The study is performed on 15 healthy volunteers at the level of the eye and the crow's-feet.
The operating protocol is as follows:
The results that are obtained, corresponding to the mean of the scores with three cycles, are presented in the table below:
It is noted that after a single application, the experts identify the active ingredient according to the invention as tightening and non-sticky, and score it at an effectiveness of 4.4.
This invention also covers the cosmetic compositions including the active ingredient according to this invention in various galenical forms, in particular gel, solution, emulsion, cream, . . . .
It is then advisable to analyze the stability of the galenical forms, including the active ingredient according to the invention, in proportions of between 1 and 5%.
The stability is characterized by an absence of precipitation of the active ingredient, an absence of creaming, and an absence of phase shift.
It is possible to cite formulations that have shown a physical stability that includes 5% of active ingredient according to the invention.
In addition, tests have shown the compatibility of the active ingredient with the raw material used in cosmetics.
Number | Date | Country | Kind |
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0653903 | Sep 2006 | FR | national |
0753714 | Mar 2007 | FR | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/FR07/51992 | 9/21/2007 | WO | 00 | 3/23/2009 |