FR2765106A1 - USE OF CROSSLINKED TANNINS IN THE PRESENCE OF NON-CROSSLINKED PROTEINS WITH TANNINS AS COSMETIC AGENTS TO IMPROVE SKIN SMOOTHING AND / OR TO OBTAIN AN ASTRINGENT EFFECT - Google Patents

Abstract

The invention concerns the use of tannins cross-linked in the presence of proteins non-cross-linked with the tannins as cosmetic agents to improve skin smoothing and/or to obtain an astringent effect. The invention also concerns a method for making a composition stable in time containing tannins in the presence of a protein, characterised in that in a first step, the tannins are cross-linked in the absence of said protein and in a second step the cross-linked tannins are mixed with said protein. The invention provides a method for the cosmetic treatment of the skin or for improving skin smoothing and/or for producing an astringent effect on the skin, in particular a toning effect.

Description

The invention essentially relates to the use of cross-linked tannins in

  presence of proteins not crosslinked with tannins as a cosmetic agent for

  improve the smoothing of the skin, for an astringent or firming effect.

  The use of tannins is very old in cosmetics. When applied externally, the tannins react with the skin and mucous membranes and cause waterproofing of the most superficial layers. Tannins are also used in cosmetics for their "firming" effects linked to their astringent properties. The use of cosmetic tannins is limited due to their instability in usual cosmetic media such as gels, creams, emulsions and lotions. In particular, they produce by degradation colored derivatives

  providing an unacceptable brownish appearance.

  Tannins are also known to also have the property of

  precipitate proteins, especially gelatin.

  Thus, a general method of assaying serum albumin is to

rush through the tannins.

  The tannins combine with proteins, and other macromolecules, thanks to hydrogen bonds between the phenolic functions of the tannins and

certain functions of proteins.

  Under these circumstances, the use of tannins has been made practically impossible in cosmetics in the presence of proteins in the same product due to

tannin-protein reactivity.

  In patent application FR-A-2 715 582 from the CNRS, microcapsules with a wall of flavonoid walls crosslinked by interfacial crosslinking are described. The crosslinking of the flavonoids makes it possible to stabilize them and prevent any changes in color over time. In addition, the specific initial activity of the flavonoids is maintained (see the aims of the invention page 2, line

9 on page 3, line 24).

  The addition of proteins, initially present, is provided in a particular embodiment so that the protein is coriculated with the flavonoid (page 4, lines 11 to 15, and examples 3, 4, 6, 8, 10, 11 , 13, 14, 16, 25 and the

claims 2 and 3 in particular).

  In the context of the present invention, it has just been unexpectedly discovered that the crosslinked tannins, combined with proteins not crosslinked with the tannins, make it possible to considerably potentiate the smoothing effect of the skin, as well as to obtain an astringent effect, of a cosmetic composition containing them, and applied topically to the skin. Thus, according to a first aspect, the present invention aims to solve the new technical problem consisting in the supply of a solution making it possible to find a new cosmetic formulation making it possible to improve the smoothing effect of the skin, and / or obtaining an astringent effect on the skin of

  preferably during topical application.

  This new technical problem is solved by the present invention of a

  way, safe and reliable, usable on an industrial scale.

  Thus, according to a first aspect, the present invention relates to the use of crosslinked tannins in the presence of protein not crosslinked with the tannins as a cosmetic agent for smoothing the skin, and / or for obtaining an effect.

astringent or firming.

  According to a particular variant embodiment, the protein is added to a

  solution containing the crosslinked tannins previously prepared.

  According to a currently preferred embodiment, the crosslinked tannins are obtained by interfacial crosslinking, in particular in the form of a microcapsule or microparticle and the abovementioned proteins are present in a solution,

  particular aqueous, containing the crosslinked tannins previously prepared.

  In the context of the invention, the tannin concentration is between 0.001% and 5%, preferably between 0.01% and 5%, and even better between 0.1% and 1%, by weight relative to the weight total of the final composition, while the protein concentration is between 0.01% and 10%, preferably between 0.1% and 10%, and even better between 1% and 5% by weight relative to the total weight

of the final composition.

  According to an advantageous embodiment of the invention, the above-mentioned tannin is a water-soluble phenolic molecule having a molecular weight of between 500 and 3,000 daltons, in particular consisting of procyanidolic oligomers, abbreviated as OPC in the pure state, or as a mixture in the form of an extract from a natural source, for example grape seed proanthocyanidins. As other tannins, mention may be made of proanthocvanidols, procyanidins, picnogenols, hydrolysable tannins and in particular esters of glucose and of phenolic acids such as gallic acid and ellagic acid, and for example, officinal tannin is obtained from oak gall (quercus infectoria). Mention may also be made of green tea extracts containing epigallocatechin, gallate and other derivatives, or extracts with complex flavonoids. In the context of the invention, the above-mentioned protein is a protein compatible with a cosmetic or pharmaceutical application, in particular a protein of animal, human or vegetable origin such as an albumin such as serum albumin, ovalbumin, cx-lactalbumin, globulins, fibrinogen, casein, collagen, atelocollagen, gelatin, gelatin hydrolysates, peptones, hemoglobin, vegetable proteins such as soy proteins, non-glytelins degraded or degraded, scleroproteins

  solubilized, proteins from milk in all its forms, soy flour.

  According to a third aspect, the present invention also covers a process for the manufacture of a composition which is stable over time and contains tannins, in particular procyanidolic or OPC oligomers, in the presence of a protein, characterized in that a first step crosslinking of the tannins, in the absence of said protein, and in a second step, the crosslinked tannins are mixed with said protein. To achieve this mixture, it is possible either to use the reaction medium containing the crosslinked tannins as such in which said protein is added, or to separate the crosslinked tannins and introduce them into

  a protein-containing solution, especially an aqueous solution.

  According to an advantageous embodiment of the invention, the crosslinking of the tannins takes place by interfacial crosslinking, and in the currently preferred case where the tannins are water-soluble, the interfacial crosslinking is carried out on an emulsion in which the dispersed phase is an aqueous phase containing the tannins in solubilized form, by an interfacial crosslinking agent present in a continuous hydrophobic phase. This interfacial crosslinking technique is advantageously that described in document FR-A-2 715 582 which is incorporated here by reference, in particular from page 6, line 30 to page 10, line 22, as well as manufacturing examples 1 to 25. It will be observed in particular that the crosslinking agent comprises a diacid chloride, dc preferably chosen from the group consisting of an aliphatic or aromatic diacid chloride, such as sebacoyl chloride, succinyl chloride, chloride d apipoyl, terephthaloyl chloride, glutaryl chloride. The concentration of diacid chloride will preferably be between 0.2% and 10% by weight of the total weight of the reaction medium. As substances used to constitute the hydrophobic phase, it is possible to use liquid substances well known to those skilled in the art such as those mentioned on page 8, lines 7 to 14, and in particular fatty acid esters such as isopropyl myristate or ethyl oleate, mixtures of commercially available fatty acid esters such as, for example, the product Dragoxat, sold by the company Dragoco, vegetable oils, such as olive oil. olive, sweet almond oil, peanut oil, mineral oils, such as paraffin oil and any mixture of these liquid and hydrophobic substances. It is understandable that vegetable oils are particularly interesting

  since they are compatible with a cosmetic or pharmaceutical application.

  It is also possible to use surfactants to facilitate the preparation of the emulsion as described on page 8, lines 15 to 22 of FR-A-2 715 582 o those skilled in the art may refer to. Thus, the crosslinked tannins can advantageously be in the form of microcapsules or microparticles during crosslinking by interfacial crosslinking. These microcapsules or microparticles generally have a diameter lying in the interval

between 0.1 m and 3 mm.

  The first step of the process of the invention consists in carrying out beforehand the crosslinking of the tannins, in the absence of proteins, and can be

  carried out in accordance with Example 1 of FR-A-2 715 582.

  During the crosslinking of tannins constituted by procyanidolic oligomers of grape seeds, abbreviated as OPC PR, the conditions of example 5 can be used, which are combined with the protocol described in example 1 of

FR-A-2 715 582.

  According to a fourth aspect, the present invention also covers a method of cosmetic treatment of the skin, to improve the smoothing of the skin, to obtain an astringent effect on the skin, in particular a firming effect, characterized in that it comprises: application to the affected areas of the skin of an effective amount of crosslinked tannins in combination with proteins not

cross-linked with tannins.

  Other alternative embodiments of this cosmetic treatment process

  result from the preceding description in relation to one or other of the three

  first aspects, as well as claims.

  The present invention will now be described in relation to a currently preferred example of the invention given simply by way of illustration and which therefore cannot in any way limit the scope of the invention, with demonstration of the smoothing activity of the skin, examples of cosmetic or pharmaceutical formulations being then also given by way of illustration. Example 1 of the invention Preparation of a composition comprising crosslinked tannins in the form of crosslinked grape seed proanthocvanidines, combined with a protein obtained from wheat, commercially available under the name of Tensin from the company Silab France The steps of process for the preparation of this composition are the following: a) Proanthocyanidin crosslinking step (OPC) from grape seeds

  To carry out this step, we proceed as described in Example 5 dc FR-

A-2,715,582.

  To do this, an aqueous phase is first prepared by dissolving 300 mg of a solution of procyanidolic oligomers from grape seeds, commercial references OPC PR, marketed by the company Sarpap, France, in 3 ml of a buffer. carbonate PH 11, or approximately 10% OPC. An emulsification is then carried out, emulsifying 3 ml of this solution in 15 ml of cyclohexane supplemented with 5% of a surfactant, such as

  than Span 85 (sorbitan trioleate), by stirring at 3000 rpm.

  Then, after 5 mm of stirring, 20 ml of a 5% w / v solution of crosslinking agents consisting of terephthaloyl chloride (CF) sold by Janssen Chimica are added to the emulsion. in a mixture of chloroform: cyclohexane in a 1: 4 volume / volume ratio and maintained

agitation for 30 minutes.

  The microcapsules obtained are then separated by centrifugation and washing by resuspension successively in cyclohexane, in 95% alcohol added with 2% Tween 20 in alcohol

  % and finally in distilled water.

  Optical microscope examination shows beautiful spherical microcapsules,

  transparencies of diameters 5-25 [lm, in the form of an aqueous suspension.

  b) Preparation of the crosslinked tannin-wheat protein mixture According to a first alternative embodiment, the microcapsules prepared in step a) are separated from the aqueous suspension containing them by centrifugation. Washings are carried out to eliminate the reaction medium. The microcapsules as well

  washed can be mixed with an aqueous solution containing wheat protein.

  By varying the respective proportions of microcapsules and wheat proteins, various compositions are obtained comprising various concentrations of crosslinked tannins, and of proteins, as is well

  understandable to those skilled in the art.

  Thus, various compositions have been prepared and they are reported to the

  Table III of the result of Example 5 given below.

  Example 2 of the invention Test for precipitation of bovine serum albumin by increasing concentrations of free and crosslinked proanthocvanidins (OPC) To carry out this test, a constant dose of commercial bovine serum albumin is used, brought into contact with increasing doses. free or crosslinked OPCs. After 15 minutes of incubation at room temperature, a

  centrifugation to remove any precipitated albuminc serum.

  A protein assay is made on the supernatant.

  A test without OPC determines the amount of serum albumin actually present in the supernatant and also defines the 100% of serum

non-precipitated albumin.

  The assay technique used is the Coomasie blue method with an optical density reading respectively at a wavelength of 590 nanometers and a wavelength of 465 nanometers to measure the absorbance called respectively Abs590 to 590 nanometers and Abs. at 465 nanometers. The Abs5J / Abs45 report is used to determine the concentration

  protein as is well understood by those skilled in the art.

  The values in Table I below are expressed as a percentage of

  bovine serum albumin or non-precipitated BSA.

  Table I: measurement of non-precipitated BSA as a percentage by weight [OPC1 ng / ml O 0.2 0.4 0.6 0.8 1 free OPC 100 83 71 54 32 il crosslinked OPC 100 100 100 99 98 98 We obtain thus the precipitation curve of bovine serum albumin or BSA represented in FIG. 1 which represents the concentration of

  tannin from 0 to 1 ng / ml ct on the ordinate the% in soluble bovine serum albumin (BSA).

  Curve 1 is the control curve without tannin, curve 2 is the curve obtained with crosslinked tannins, here crosslinked OPCs and curve 3 is the curve

  obtained with free tannins, here free or uncrosslinked OPCs.

  It can be seen from Table I and FIG. 1 that when the OPCs are crosslinked, there is essentially no precipitation of the protein, unlike

Free OPCs.

  Example 3 of the invention Interaction test between type 1 collagen and free or crosslinked OPCs The collagen-tannin interaction due to the expression of hydrogen bonds results in an increase in the rate of crosslinking of collagen and by

consequently of its viscosity.

  In this test, a constant concentration of type 1 collagen is used

  in the presence of an increasing concentration of free and crosslinked OPC.

  The viscosity of the mixture is measured using a Ubbelohde viscometer, commercially available, well known to those skilled in the art, ref. 0.78 IT, at a temperature of 29 C. The results of this test are reported in FIG. 2 which represents on the abscissa the concentration in% of OPC which varies from 0 to 0.25%, depending on the relative viscosity in ordered for a constant collagen concentration of

  0.05% type 1 in water at 29 C.

  Curve 1 is obtained with the control collagen solution, curve 2 is obtained by adding an increasing concentration of free OPC and curve 3 is obtained by adding to the solution of collagen an increasing concentration of OPC

  crosslinked, obtained according to example la).

  This second test confirms the absence of a bridging phenomenon between proteins and crosslinked OPCs, unlike the well-known phenomenon observed.

with free mutual funds.

  EXAMPLE 4 OF THE INVENTION Hydrolysis kinetics test by an esterase of crosslinked OPCs The microcapsules of OPCs as obtained in Example la are used. These

  OPC microcapsules are formed as a result of ester linkages.

  The membrane which is formed therefore consists of esterified flavonoids.

  It is demonstrated by the present test that under the action of esterase, there is

  release over time of procyanidol monomers.

  The present test consists in bringing together 286 esterase units, constituted by an E 3019 esterase of porcine pancreatic origin commercially available from Sigma, with crosslinked OPCs according to example la, and after centrifugation at different times (30 mins; 1 hour; 2 hours; 3 hours; 4 hours and

  6 hours), the composition of the supernatant is visualized by HPLC chromatography.

  The appearance of monomers in the supernatant is very clear, which proves

the action of esterase.

  The results obtained are listed in Table II below: Table II: Hydrolysis by an esterase of crosslinked OPCs

TIME (HOURS)

0.5 12 13 4 16

  OPCliberate (%) 17 39 79 94 97 100 It is known that esterases are secreted from Ocland bodies in the stratum granulosum which will migrate to the surface of the stratum comeum. The presence of esterases in the surface layer of the skin will allow an attack on the crosslinked OPC microcapsules and thus release the procyanidic oligomers endowed with tanning property and which will crosslink the collagen present in the surface layer of the skin. and thus provide the smoothing effect of the skin demonstrated by the present invention, which is confirmed by

the smoothing tests below.

Example 5 of the invention

SKIN SMOOTHING TESTS

  Skin smoothing tests were carried out on a group of 32

volunteer people.

  Each person received on different skin areas of one of the forearms, 4 different compositions according to the invention, as prepared for

Example 1.

  On a skin area of the other forearm, they receive a control composition consisting solely of the excipient of said compositions.

Example 1.

  Only one application of each composition is made.

  Two hours after the application of the compositions, a skin impression on the application areas is carried out, according to a well-known technique of

one skilled in the art.

  A study of the depressive micro-relief of skin wrinkles is then

  made from these prints, using a conventional image analyzer.

  The results obtained, representing the average of the observations by

  with respect to the control fingerprints, are reported in Table III below.

  In this table, the indication + signifies a non-significant effect, The indication + signifies a slight skin smoothing effect, The indication ++ signifies a slight smoothing of the skin, The indication +++ signifies a marked reduction in wrinkles and a fairly satisfactory smoothing of the skin, The ++++ indication means a very marked reduction in the depth of

  wrinkles and smoothing of the skin very satisfactory.

  In Table III below, the concentrations of protein (tensin) and of tannins, namely of proanthocyanidolic oligomers of crosslinked grape seeds (crosslinked OPCpR) are expressed as a percentage by weight, relative to the total weight.

of the final composition.

  Table III Effect of the compositions of the invention on the smoothing of the skin

TENSINE%

0 1 2 3

CROSSLINKED OPCR%

0 0 + + +

0.1 ++ ++

0.3 + ++ ++ +++

0.5 + +++ ++++ +++

  It follows from Table III above, that the combination of crosslinked tannins with at least one protein, here wheat proteins, gives a significant result on skin smoothing, whereas in the absence of crosslinked tannins, this effect is only of little significance, whatever the protein concentration tested. Likewise, in the absence of protein, the crosslinked tannins showed only a moderate effect on skin smoothness. There is therefore a synergistic effect highlighted between the tannins

  crosslinked and the protein combined together, in accordance with the invention.

  Example 6 of the invention Composition called "radiance boost" for smoothing the skin of the face This composition is prepared from the following ingredients: - crosslinked OPC microcapsules, according to example la ........ .............. 1 g, - Carbopol 940 ...................

  .................................................. ..... 0.05 g, tensin ......................................... .......................... .DTD: ................... 5g. .DTD: - aqueous scented excipient with preservative qs ...................... 100 g.

  To prepare this composition, the 5 g of tensin are dissolved in approximately 40 g of distilled water, cold with mechanical stirring, then 1 g of the crosslinked OPC microcapsules prepared according to Example 1a is dispersed. While maintaining stirring, make up to 50 g with an aqueous excipient containing the perfume and the preservatives. 50 g of Carbopol 940 gel are then added to

  0.1% neutralized with sodium hydroxide prepared separately.

  A composition is thus obtained in the form of a gel which, applied to the skin of the face, produces in a few minutes a tightening effect which smoothes the skin in

  reducing wrinkles and fine lines.

12 2765106

Claims (14)

  1. Use of crosslinked tannins in the presence of non-protein   crosslinked with tannins as a cosmetic agent for smoothing the skin and / or for obtaining an astringent effect. 2. Use according to claim 1 characterized in that the protein is added to a solution containing the crosslinked tannins previously prepared.   3. Use according to one of the preceding claims, characterized   in that the crosslinked tannins are obtained by interfacial crosslinking, in particular in the form of microcapsules or microparticles and the abovementioned proteins are present in a solution, in particular aqueous, containing the tannins previously prepared.   4. Use according to claim 1 to 3, characterized in that the tannin concentration is between 0.001% and 5%, preferably between 0.01% and 5% and even better between 0.1% and 1%, in weight relative to the total weight of the final composition, while the protein concentration is between 0.01% and 10%, preferably between 0.1% and 10%, still micux between 1% and% by weight relative the total weight of the final composition containing them.   5. Use according to any of claims 1 to 4, characterized in that   that the aforementioned tannin is a water-soluble phenolic molecule having a molecular weight of between 500 and 3000 Daltons, in particular constituted by procyanidolic oligomers OPC in the pure state, or in the state of mixture in the form of extract from natural source , for example seed pips proanthocyanidins grape.   6. Use according to one of the preceding claims, characterized   in that the aforementioned protein is a protein compatible with a cosmetic or pharmaceutical application, in particular a protein of human or vegetable animal origin such as an albumin such as serum albumin, ovalbumin, c-lactalbumin, globulins , fibrinogen, casein, collagen, atelocollagen, gelatin, gelatin hydrolysates, peptones, hemoglobin, vegetable proteins such as soy proteins, glytelins in non-degraded or degraded form, scleroproteins solubilized,   proteins from milk in all its forms, soy flour. 13 2765106   7. A method of manufacturing a composition stable over time containing tannins, in particular procyanidolic oligomers or OPC, in the presence of a protein, characterized in that one carries out in a first step the crosslinking of tannins in the absence of said protein and in a second step, the crosslinked tannins are mixed with said protein. 8. Method according to claim 7, characterized in that the crosslinking of the tannins takes place by interfacial crosslinking, in particular in the form of a microcapsule or microparticle and the abovementioned proteins are present in a solution, in particular aqueous, containing the previously crosslinked tannins prepared.   9. A method of cosmetic treatment of the skin, to improve the smoothing of the skin, to obtain an astringent effect on the skin, in particular a firming effect, characterized in that it comprises application to the areas of the skin concerned an effective amount of crosslinked tannins cn presence of proteins not cross-linked with tannins.   10. Method according to claims 7 to 9, characterized in that the   crosslinked tannins are obtained by interfacial crosslinking, in particular in the form of microcapsules or microparticles and the abovementioned proteins are present in a solution, in particular an aqueous solution, containing the crosslinked tannins having been   separately previously prepared.   11. Method according to one of claims 7 to 10, characterized in that   the tannin concentration is between 0.001% and 5%, preferably between 0.01% and 5%, and even better between 0.1% and 1%, by weight relative to the total weight of the composition, while the protein concentration is between 0.01% and 10%, preferably between 0.1% and 10%, even better between 1% and 5%   weight relative to the total weight of the composition containing them.   12. Method according to one of claims 7 to 11, characterized in that   the aforementioned tannin is a water-soluble phenolic molecule having a molecular weight of between 500 and 3,000 Daltons, in particular constituted by procyanidolic oligomers OPC in the pure state, or in the form of a mixture in the form of extract from a natural source, for example grape seed proanthocvanidines.   13. Method according to one of claims 7 to 12, characterized in that   the aforementioned protein is a protein compatible with a cosmetic application 14 27 651 06   or pharmaceutical, in particular a protein of animal, human or   vegetable such as albumin such as serum albumin, ovalbumin, cc-   lactalbumin, globulins, fibrinogen, casein, collagen, atelocollagen, gelatin, gelatin hydrolysates, peptones, hemoglobin, vegetable proteins such as soy proteins, glytelins in non-degraded form or degraded, solubilized scleroproteins,   proteins from milk in all its forms, soy flour.