DESCRIPTION
TITLE OF INVENTION
STABLE COMPOSITION COMPRISING
RETINOID AND ASCORBIC ACID COMPOUND
TECHNICAL FIELD
The present invention relates to a composition, preferably a cosmetic composition, which is stable and comprises at least one retinoid and at least one ascorbic acid compound.
BACKGROUND ART
Retinoids have been known to be useful in the field of, for example, cosmetics because they can function as anti-aging active ingredients which may be used for wrinkle treatments and the like.
Ascorbic acid or vitamin C and its derivatives (ascorbic acid compounds) are commonly used as a result of their many beneficial properties. In particular, ascorbic acid stimulates the synthesis of the connective tissue and in particular of collagen, strengthens the defenses of the cutaneous tissue against external attacks, such as ultraviolet radiation and pollution, compensates for vitamin E deficiency of the skin, depigments the skin and has a role in combating free radicals. These last two properties make it an excellent candidate as cosmetic or dermatological active principle for combating ageing of the skin or for preventing ageing of the skin.
DISCLOSURE OF INVENTION
It has been discovered that if retinoid and ascorbic acid compound are contacted in a single composition, the composition is destabilized such that the color (in particular, brightness among the three attributes of color) of the composition changes.
An objective of the present invention is to provide a composition including both at least one retinoid and at least one ascorbic acid compound wherein the composition is stable such that the change in color (in particular, brightness) of the composition can be reduced.
The above objective of the present invention can be achieved by a composition, preferably a cosmetic composition, and more preferably a skin cosmetic composition, comprising:
(1) a plurality of capsules each of which comprises at least one core, and at least one shell surrounding the core, wherein the core comprises (a) at least one retinoid, and (b) at least one oil, and the shell comprises (c) at least one polysaccharide; and
(2) an aqueous phase comprising (d) at least one ascorbic acid compound, and (e) water, wherein the (1) capsules are dispersed in the (2) aqueous phase. The (a) retinoid may be retinol.
The amount of the (a) retinoid(s) in the composition according to the present invention may range from 0.01% to 15% by weight, preferably from 0.05% to 10% by weight, and more preferably from 0.1% to 5% by weight, relative to the total weight of the composition.
The (b) oil may be selected from triglycerides, preferably triglycerides having at least one unsaturated fatty acid residue, and more preferably triglycerides having at least one polyunsaturated fatty acid residue.
The (b) oil may be selected from plant oils, preferably selected from the group consisting of soybean oil, com oil, cotton seed oil, grape seed oil, and a mixture thereof.
The amount of the (b) oil(s) in the composition according to the present invention may range from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, and more preferably from 1% to 10% by weight, relative to the total weight of the composition.
The (c) polysaccharide may be selected from agar, alginate, carrageenan and a mixture thereof.
The amount of the (c) polysaccharide(s) in the composition according to the present invention may range from 0.001% to 5% by weight, preferably from 0.005% to 3% by weight, and more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.
The (d) ascorbic acid compound may be selected from ascorbic acid, ascorbic acid salts, ascorbic acid esters and mixtures thereof.
The amount of the (d) ascorbic acid compound(s) in the composition according to the present invention may range from 0.1% to 25% by weight, preferably from 0.5% to 20% by weight, and more preferably from 1% to 15% by weight, relative to the total weight of the composition.
The amount of the (e) water in the composition according to the present invention may range from 50% to 90% by weight, preferably from 55% to 85% by weight, and more preferably from 60% to 80% by weight, relative to the total weight of the composition.
The core may further comprise (f) at least one lipophilic antioxidant agent, preferably selected from biodegradable lipophilic antioxidant agents, and more preferably selected from the group consisting of tocopherol, pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate, and a mixture thereof.
The amount of the (f) lipophilic antioxidant agent(s) in the composition according to the amended claims may range from 0.01% to 5% by weight, preferably from 0.05% to 3% by weight, and more preferably from 0.1% to 1% by weight, relative to the total weight of the composition.
The aqueous phase may further comprise (g) at least one compound which is capable of providing a solution thereof with a transmittance of 10% or less, preferably 5% or less, and more preferably 2% or less, for light with a wavelength of from 290 to 420 run, along a light path length of 10 mm, the concentration of the compound in the solution being 0.9% by weight relative to the total weight of the solution.
The present invention also relates to a cosmetic process for treating a keratin substance such as skin, comprising the step of applying the composition according to the present invention to the keratin substance.
BEST MODE FOR CARRYING OUT THE INVENTION
After diligent research, the inventors have discovered that it is possible to provide a composition including both at least one retinoid and at least one ascorbic acid compound wherein the composition is stable such that the change in color (in particular, brightness) of the composition can be reduced.
The composition according to the present invention may be characterized by separating a retinoid and an ascorbic acid compound in a single composition by encapsulating the retinoid into a capsule such that the ascorbic acid compound which is not present in the capsule is difficult to contact the retinoid in the capsule.
Since the contact between retinoid and ascorbic acid compound in a single composition is limited in the present invention, the destabilization (e.g., change in color, in particular brightness) of the composition caused by the contact of the retinoid and the ascorbic acid compound can be reduced.
Thus, the composition according to the present invention is stable and the color change (in particular, in brightness) of the composition over time can be reduced.
According to the present invention, the capsule includes not only retinoid but also oil, and the capsules are dispersed in an aqueous phase including the ascorbic acid compound and water. Therefore, the composition according to the present invention can be in the form of an O/W type.
Since the composition according to the present invention is stable or the change in color (in particular, brightness) of the composition over time can be reduced, the composition according to the present invention can be stored for a long period of time.
The composition according to the present invention can provide cosmetic effects base on, at least, the retinoid and the ascorbic acid compound included in the composition.
The composition according to the present invention can provide stable cosmetic effects, such as anti-aging (e.g., diminishing wrinkles), whitening skin, improving skin dullness, and improving skin smoothness, over time, based on the retinoid and the ascorbic acid compound in the composition.
The composition according to the present invention can include a higher amount of retinoid and a higher amount of ascorbic acid compound. Therefore, the composition according to the present invention can provide enhanced cosmetic effects, and possibly synergistic cosmetic effects, by a combination of the higher amount of retinoid and the higher amount of ascorbic acid compound.
Hereinafter, the composition according to the present invention will be explained in a more detailed manner.
[Retinoid]
The composition according to the present invention comprises (a) at least one retinoid. Two or more retinoids may be used in combination. Thus, a single type of retinoid or a combination of different types of retinoid may be used.
The (a) retinoid may be retinol (vitamin A), retinal (vitamin A aldehyde), retinoic acid (vitamin A acid), or an ester of retinol and of a C2-20 acid, such as the propionate, the acetate, the linoleate or the palmitate of retinol (retinyl palmitate).
Among the (a) retinoid, mention may be made of retinol, retinal, retinoic acid, in particular all-trans retinoic acid and 13 -cis retinoic acid, retinol derivatives, such as retinyl acetate, propionate or palmitate, and the retinoids described in the following patent applications: FR 2 370 377, EP 0 199 636. EP 0 325 540 and EP 0 402 072:
According to one preferred embodiment of the present invention, the (a) retinoid is retinol or proretinol.
The term "retinol" is intended to mean all the isomers of retinol, i.e., all-trans retinol, 13 -cis retinol, 11-cis retinol, 9-cis retinol and 3,4-didehydro retinol.
As a representative of proretinol, mention may be made of retinyl palmitate.
It is preferable that the (a) retinoid be retinol.
The amount of the (a) retinoid(s) in the composition according to the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more, relative to the total weight of the composition.
Alternatively, the amount of the (a) retinoid(s) in the composition according to the present invention may be 0.5% by weight or more, preferably 1.0% by weight or more, and more preferably 1.5% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (a) retinoid(s) in the composition, according to the present invention may be 15% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less, relative to the total weight of the composition.
The amount of the (a) retinoid(s) in the composition according to the present invention may range from 0.01% to 15% by weight, preferably from 0.05% to 10% by weight, more preferably from 0.1% to 5% by weight, relative to the total weight of the composition.
Alternatively, the amount of the (a) retinoid(s) in the composition according to the present invention may range from 0.5% to 15% by weight, preferably from 1.0% to 10% by weight, more preferably from 1.5% to 5% by weight, relative to the total weight of the composition.
[Oil]
The composition according to the present invention comprises (b) at least one oil. Two or more oils may be used in combination. Thus, a single type of oil or a combination of different types of oils may be used.
Here, “oil” means a fatty compound or substance which is in the form of a liquid or a paste (non-solid) at room temperature (25°C) under atmospheric pressure (760 mmHg). As oils, those generally used in cosmetics can be used alone or in combination thereof. These oils may be volatile or non-volatile.
It is preferable that the (a) retinoid be soluble in the (b) oil. In other words, it is preferable to use the (b) oil in which the (a) retinoid is soluble.
The (b) oil may be selected from polar or non-polar oils.
The term "polar oil" here means any lipophilic compound having, at 25°C, a solubility parameter 8d characteristic of dispersive interactions of greater than 16 and a solubility parameter 8P characteristic of polar interactions strictly greater than 0. The solubility parameters 8d and 8P are defined according to the Hansen classification.
The definition and calculation of the solubility parameters in the Hansen three-dimensional solubility space are described in the paper by C. M. Hansen: "The three dimensional solubility parameters", J. Paint Technol. 39, 105 (1967).
According to this Hansen space:
3D characterizes the London dispersion forces derived from the formation of dipoles induced during molecular impacts;
8P characterizes the Debye interaction forces between permanent dipoles and also the Keesom interaction forces between induced dipoles and permanent dipoles;
8h characterizes the specific interaction forces (such as hydrogen bonding, acid/base, donor/acceptor, etc.); and
8a is determined by the equation: 8a=(8p2+8h1)1/2. The parameters 8P, 8h, 8d and 8a are expressed in (J/cm3)1/2.
It may be preferable that polar oil be selected from the group consisting of plant or animal oils, such as triglycerides, ester oils, ether oils and mixtures thereof, more preferably from the group consisting of ester oils, ether oils and mixtures thereof, and even more preferably from ester oils.
The polar oil may be chosen especially from the following oils: hydrocarbon-based polar oils such as phytostearyl esters, such as phytostearyl oleate, phytostearyl isostearate and lauroyl/octyldodecyl/phytostearyl glutamate (Ajinomoto, Eldew PS203), triglycerides consisting of fatty acid esters of glycerol, in particular the fatty acids of which may have chain lengths ranging from C4 to C36, and especially from Cis to C36, these oils possibly being linear or branched, and saturated or unsaturated; these oils may especially be heptanoic or octanoic triglycerides, wheatgerm oil, sunflower oil, grapeseed oil, sesame seed oil (820.6 g/mol), com oil, apricot oil, castor oil, shea oil, avocado oil, olive oil, soybean oil, sweet almond oil, palm oil, rapeseed oil, cottonseed oil, hazelnut oil, macadamia oil, jojoba oil, alfalfa oil, poppy oil, pumpkin oil, marrow oil, blackcurrant oil, evening primrose oil, millet oil, barley oil, quinoa oil, rye oil, safflower oil, candlenut oil, passionflower oil or musk rose oil; shea butter; or alternatively caprylic/capric acid triglycerides, for instance those sold by the company Stearineries Dubois or those sold under the names Miglyol 810®, 812® and 818® by the company Dynamit Nobel; synthetic ethers containing from 10 to 40 carbon atoms, such as dicaprylyl ether; hydrocarbon-based esters of formula RCOOR' in which RCOO represents a carboxylic acid residue comprising from 2 to 40 carbon atoms, and R' represents a hydrocarbon-based chain containing from 1 to 40 carbon atoms, such as cetostearyl octanoate, isopropyl alcohol esters, such as isopropyl myristate or isopropyl palmitate, ethyl palmitate, isopropyl stearate or isostearate, isostearyl isostearate, octyl stearate, diisopropyl adipate, heptanoates, and especially isostearyl heptanoate, alcohol or polyalcohol octanoates, decanoates or ricinoleates, for instance propylene glycol dioctanoate, cetyl octanoate, tridecyl octanoate, 2-ethylhexyl 4-diheptanoate and palmitate, alkyl benzoate, polyethylene glycol diheptanoate, propylene glycol 2- diethyl hexanoate, and mixtures thereof, C12 to C15 alcohol benzoates, hexyl laurate, neopentanoic acid esters, for instance isodecyl neopentanoate, isotridecyl neopentanoate, isostearyl neopentanoate and 2-octyldodecyl neopentanoate, isononanoic acid esters, for instance isononyl isononanoate, isotridecyl isononanoate and octyl isononanoate, oleyl erucate, isopropyl lauroyl sarcosinate, diisopropyl sebacate, isocetyl stearate, isodecyl neopentanoate, isostearyl behenate, and myristyl myristate; polyesters obtained by condensation of an unsaturated fatty acid dimer and/or trimer and of diol, such as those described in patent application FR 0 853 634, in particular such as dilinoleic acid and 1,4-butanediol. Mention may especially be made in this respect of the polymer sold by Biosynthis under the name Viscoplast 14436H (INCI name: dilinoleic acid/butanediol copolymer), or else copolymers of polyols and of dimer diacids, and esters thereof, such as Hailuscent ISDA; polyol esters and pentaerythritol esters, for instance dipentaerythrityl tetrahydroxystearate/tetraisostearate; fatty alcohols containing from 12 to 26 carbon atoms, for instance octyldodecanol, 2- butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol and oleyl alcohol; higher C12-C22 fatty acids, such as oleic acid, linoleic acid and linolenic acid, and mixtures thereof; fatty acids containing from 12 to 26 carbon atoms, for instance oleic acid; dialkyl carbonates, the two alkyl chains possibly being identical or different, such as dicaprylyl carbonate sold under the name Cetiol CC® by Cognis; and non-volatile oils of high molecular mass, for example between 400 and 10 000 g/mol, in particular between 650 and 10 000 g/mol, for instance: i) vinylpyrrolidone copolymers such as the vinylpyrrolidone/ 1 -hexadecene copolymer, Antaron V-216 sold or manufactured by the company ISP (MW=7300 g/mol), ii) esters such as: a) linear fatty acid esters with a total carbon number ranging from 35 to 70, for instance pentaerythrityl tetrapelargonate (MW=697.05 g/mol), b) hydroxylated esters such as polyglycerol-2 triisostearate (MW=965.58 g/mol), c) aromatic esters such as tridecyl trimellitate (MW=757.19 g/mol), C12-C15 alcohol benzoate, the 2-phenylethyl ester of benzoic acid, and butyloctyl salicylate, d) esters of C24-C28 branched fatty acids or fatty alcohols such as those described in patent application EP-A-0 955 039, and especially triisoarachidyl citrate (MW=1033.76 g/mol), pentaerythrityl tetraisononanoate (MW=697.05 g/mol), glyceryl triisostearate (MW=891.51 g/mol), glyceryl tris(2-decyl)tetradecanoate (MW=1143.98 g/mol), pentaerythrityl tetraisostearate (MW=1202.02 g/mol), polyglyceryl-2 tetraiso stearate (MW=1232.04 g/mol) or else pentaerythrityl tetrakis(2- decyl)tetradecanoate (MW=1538.66 g/mol), e) esters and polyesters of dimer diol and of monocarboxylic or dicarboxylic acid, such as esters of dimer diol and of fatty acid and esters of dimer diol and of dimer dicarboxylic acid, such as Lusplan DD-DA5® and Lusplan DD-DA7® sold by the company Nippon Fine Chemical and described in patent application US 2004-175 338, the content of which is incorporated into the present application by reference, and mixtures thereof.
The term "polar hydrocarbon-based oil" here means a polar oil formed essentially from, or even constituted by, carbon and hydrogen atoms, and optionally oxygen and nitrogen atoms, and not containing any silicon or fluorine atoms. It may contain alcohol, ester, ether, carboxylic acid, amine and/or amide groups.
It is preferable that the (b) oil has a logP value of 7.0 or less, more preferably 6.5 or less, and even more preferably 6.0 or less. It may be preferable that the (b) oil has a logP value of 1.0 or more, more preferably 1.5 or more, and even more preferably 2.0 or more. Thus, it may be preferable that the (b) oil has a logP value of from 1.0 to 7.0, more preferably from 1.5 to 6.5, and even more preferably from 2.0 to 6.0.
A logP value is a value for the base-ten logarithm of the apparent octan-l-ol/water partition coefficient. The logP values are known and are determined by a standard test which determines the concentration of the (b) oil in octan-l-ol and water. The logP may be calculated according to the method described in the article by Meylan and Howard: Atom/Fragment contribution method for estimating octanol-water partition coefficients, J. Pharm. Sci., 84: 83-92, 1995. This value may also be calculated using numerous commercially available software packages, which determine the logP as a function of the structure of a molecule. By way of example, mention may be made of the Epiwin software from the United States Environmental Agency.
The values may especially be calculated using the ACD (Advanced Chemistry Development) Solaris software V4.67; they may also be obtained from Exploring QSAR: hydrophobic, electronic and steric constants (ACS professional reference book, 1995). There is also an Internet site which provides estimated values (address: http://esc.syrres.com/interkow/kowdemo.htm).
The (b) oil may have at least two moieties selected from the group consisting of an amide bond, an ester bond, and mixtures thereof. The amide bond here means -CONR- (R denotes a hydrogen atom or a linear or branched Ci-Cis alkyl group, preferably a methyl group) and the ester bond here means -COO-. In other words, the (b) oil may have two or more amide bonds, two or more ester bonds or a mixture of at least one amide bond and at least one ester bond.
The (b) oil may have at least two moieties selected from the group consisting of an ether bond, an ester bond, and mixtures thereof. The ether bond here means -O- and the ester bond here means -COO-. In other words, the (b) oil may have two or more ether bonds, two or more ester bonds or a mixture of at least one ether bond and at least one ester bond.
It may be preferable that the (b) oil be selected from the group consisting of isopropyl lauroyl sarcosinate, octyldodecanol and a mixture thereof.
On the other hand, as an example of the non-polar oil, mention may be made of squalane.
The (b) oil may be selected form triglycerides. Triglyceride is an ester derived from glycerol and three fatty acids, and may be referred to as triacylglycerol.
It is preferable that the triglyceride for the (b) oil have at least one unsaturated fatty acid residue. In other words, it is preferable that the triglyceride for the (b) oil be an ester derived from glycerol and at least one unsaturated fatty acid. Thus, the triglyceride for the (b) oil may be (i) an ester derived from glycerol and one unsaturated fatty acid and two saturated fatty acids, (ii) an ester derived from glycerol and two unsaturated fatty acids and one saturated fatty acid, or (iii) an ester derived from three unsaturated fatty acids. If two or more unsaturated fatty acids are used, they may be the same or different. If two saturated fatty acids are used, they may be the same or different.
According to the present invention, "unsaturated fatty acid" means a fatty acid comprising at least one carbon-carbon double or triple bond. They are more particularly fatty acids with long chains, i.e., being able to have 8-32 carbon atoms, preferably 12-26 carbon atoms, and more preferably 14-22 carbon atoms.
The fatty acids can be monounsaturated such as petroselenic acid (Cl 2), palmitoleic acid (Cl 6) and oleic acid (Cl 8), or can be polyunsaturated, i.e., presenting at least two carboncarbon double bonds, such as linoleic acid (Cl 8) and linolenic acid (Cl 8).
It is more preferable that the triglyceride for the (b) oil have at least one polyunsaturated fatty acid residue. In other words, it is more preferable that the triglyceride for the (b) oil be an ester derived from glycerol and at least one polyunsaturated fatty acid.
The polyunsaturated fatty acid may be selected from co-3, a>-6, and co-9 fatty acids, characterized by the closest unsaturation position to the terminal methyl group.
The polyunsaturated fatty acid comprising between 18 and 22 carbon atoms, notably those selected from co-3 and co-6 fatty acids, may be more preferable.
Among the polyunsaturated fatty acids of the co-3 series, mention may be made of a-linolenic acid (18:3, co-3), stearidonic acid (18:4, co-3), 5,8,11,14, 17-eicosapentaenoic acid or EPA (20:5, co-3), and 4,7,10,13,16,19-docosahexaenoic acid or DHA (22:6, co-3), docosapentaenoic acid (22,5, co-3), and n-butyl-5,11,14-eicosatrienonic acid.
Among the polyunsaturated fatty acids of the co-6 series, mention may be made of linolenic acid with 18 carbon atoms and two unsaturations (18:2, co-6), y-linolenic acid with 18 carbon atoms and three unsaturations (18:3, co-6), dihomogamalinolenic acid with 20 carbon atoms and 3 unsaturations (20:3, co-6), arachidonic acid or 5,8,11,14 eicosatetraenoic acid (20:4, co- 6), and docosatetraenoic acid (22:4, co-6).
As the co-9 fatty acid, mention may be made of mead acid (20:3, co-9). The polyunsaturated fatty acid may be selected form a-linolenic acid, y-linolenic acid, stearidonic acid, eicosapentaenoic acid, docosahexaenoic acid, mixtures thereof.
The amount of the polyunsaturated fatty acid among the fatty acids forming the fatty acid residues in the triglyceride for the (b) oil may be 10% by weight or more, preferably 30% by weight or more, and more preferably 50% by weight or more, relative to the total weight of the fatty acids.
The weight ratio of the amount of polyunsaturated fatty acid(s)/the amount of monounsaturated fatty acid(s) among the fatty acids forming the fatty acid residues in the triglyceride for the (b) oil may be more than 1.0, preferably more than 1.5, and more preferably more than 2.0.
The (b) oil may be selected from plant oils.
For example, the (b) oil may be selected from the group consisting of soybean oil, rapeseed oil, cotton seed oil, rice oil, com oil, grape seed oil, sesame oil, linseed oil, and a mixture thereof.
It is preferable that the (b) oil be selected from the group consisting of soybean oil, com oil, cotton seed oil, grape seed oil, and a mixture thereof.
The amount of the (b) oil(s) in the composition according to the present invention may be 0.1% by weight or more, preferably 0.5% by weight or more, and more preferably 1% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (b) oil(s) in the composition according to the present invention may be 20% by weight or less, preferably 15% by weight or less, and more preferably 10% by weight or less, relative to the total weight of the composition.
The amount of the (b) oil(s) in the composition according to the present invention may range from 0.1% to 20% by weight, preferably from 0.5% to 15% by weight, more preferably from 1% to 10% by weight, relative to the total weight of the composition.
The (b) oil(s) can form a fatty phase of the composition according to the present invention. The (b) oil can form dispersed fatty phases in the composition according to the present invention.
[Polysaccharide]
The composition according to the present invention comprises (c) at least one polysaccharide. A single type of polysaccharide may be used, but two or more different types of polysaccharide may be used in combination.
It is preferable that the (c) polysaccharide be selected from polysaccharides derived from plants. In other words, it is preferable that the (c) polysaccharide be of plant origin.
On the other hand, it is also preferable that the (c) polysaccharide not be selected from cellulose and derivatives thereof. According to the present invention, the term "polysaccharides derived from plants" especially means polysaccharides obtained from the plant kingdom (plants or algae), as opposed to polysaccharides obtained via biotechnology, as is the case, for example, for xanthan gum, which is produced especially by fermentation of a bacterium, Xanthomonas campestris.
As examples of polysaccharides of plant origin that may be used according to the present invention, mention may be made especially of: a) algal extracts, such as alginates, carrageenans and agars, and mixtures thereof.
Examples of carrageenans that may be mentioned include Satiagum UTC30® and UTC10® from the company Degussa; an alginate that may be mentioned is the sodium alginate sold under the name Kelcosol® by the company ISP; b) gums, such as guar gum and nonionic derivatives thereof (hydroxypropyl guar), gum arabic, konjac gum or mannan gum, gum tragacanth, ghatti gum, karaya gum or locust bean gum; examples that may be mentioned include the guar gum sold under the name Jaguar HP 105® by the company Rhodia; the mannan and konjac gum® (1% gluconomannan) sold by the company GfN; c) modified or unmodified starches, such as those obtained, for example, from cereals, for instance wheat, com or rice, from legumes, for instance blonde pea, from tubers, for instance potato or cassava, and tapioca starches; dextrins, such as com dextrins; examples that may especially be mentioned include the rice starch Remy DR I® sold by the company Remy; the com starch B® from the company Roquette; the potato starch modified with 2-chloroethylaminodipropionic acid neutralized with sodium hydroxide, sold under the name Structure Solanace® by the company National Starch; the native tapioca starch powder sold under the name Tapioca pure® by the company National Starch; d) dextrins, such as the dextrin extracted from com under the name Index® from the company National Starch; and mixtures thereof.
Preferably, the (c) polysaccharide be chosen from algal extracts.
The algal extracts may be chosen from alginates, carrageenans and agars, and mixtures thereof. Preferably, alginates or agars, or mixtures thereof, may be used.
The amount of the (c) polysaccharide(s) in the composition according to the present invention may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (c) polysaccharide(s) in the composition according to the present invention may be 5% by weight or less, preferably 3% by weight or less, and more preferably 1% by weight or less, relative to the total weight of the composition.
The amount of the (c) polysaccharide(s) in the composition according to the present invention may range from 0.001% to 5% by weight, preferably from 0.005% to 3% by weight, more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.
[Ascorbic Acid Compound]
The composition according to the present invention comprises (d) at least one ascorbic acid compound. A single type of ascorbic acid compound may be used, but two or more different types of ascorbic acid compounds may be used in combination.
The term “ascorbic acid compound” here encompasses ascorbic acid or vitamin C, and derivatives thereof.
Ascorbic acid is generally but not necessarily in L form if it is extracted from natural products.
The derivative of ascorbic acid may be a salt of ascorbic acid, such as sodium ascorbate, potassium ascorbate, and calcium ascorbate.
On account of its chemical structure (a-keto lactone), which makes it very sensitive to certain environmental parameters such as light, heat and aqueous media, it may be advantageous to use an ascorbic acid derivative in the form of a saccharide ester of ascorbic acid or a metal salt of phosphorylated ascorbic acid.
The saccharide esters of ascorbic acid that may be used in the present invention are especially glycosyl, mannosyl, fructosyl, fucosyl, galactosyl, N-acetylglucosamine, N-acetylmuramic derivatives of ascorbic acid and mixtures thereof, and more especially ascorbyl-2 glucoside or 2-O-a-D glucopyranosyl of L-ascorbic acid or 6-O-D galactopyranosyl of L-ascorbic acid. The latter compounds and processes for preparing them are described in particular in documents EP-A-487 404, EP-A-425 066 and J-05 213 736.
For its part, the metal salt of phosphorylated ascorbic acid may be chosen from alkali metal ascorbyl phosphates, alkaline-earth metal ascorbyl phosphates and transition metal ascorbyl phosphates.
It may be preferable that the derivatives of ascorbic acid be selected from salts of ascorbic acid or phosphorylated ascorbic acid, such as, especially, sodium ascorbate, sodium or magnesium ascorbyl phosphate, acetic ester of ascorbic acid, or sugar esters of ascorbic acid, including saccharide esters and especially such as glycosyl ascorbic acid.
If necessary, stabilization of ascorbic acid towards oxidation may be obtained by combining it with maleic anhydride derivatives, as described in patent application EP 1 374 852, or with imidazole polymers, as described in patent application FR 2 832 630.
The (d) ascorbic acid compound is not lipophilic or oil-soluble but hydrophilic or water- soluble. Thus, it is preferable for the (d) ascorbic acid compound not to be a fatty acid ester of ascorbic acid such as ascorbyl palmitate, ascorbyl isopalmitate and ascorbyl stearate.
It is preferable to use ascorbic acid as the (d) ascorbic acid compound.
The amount of the (d) ascorbic acid compound(s) in the composition according to the present invention may be 0.1% by weight or more, preferably 0.5% by weight or more, and more preferably 1% by weight or more, relative to the total weight of the composition.
Alternatively, the amount of the (d) ascorbic acid compound(s) in the composition according to the present invention may be 3% by weight or more, preferably 5% by weight or more, and more preferably 10% by weight or more, relative to the total weight of the composition. On the other hand, the amount of the (d) ascorbic acid compound(s) in the composition according to the present invention may be 25% by weight or less, preferably 20% by weight or less, and more preferably 15% by weight or less, relative to the total weight of the composition.
The amount of the (d) ascorbic acid compound(s) in the composition according to the present invention may range from 0.1% to 25% by weight, preferably from 0.5% to 20% by weight, more preferably from 1% to 15% by weight, relative to the total weight of the composition.
Alternatively, the amount of the (d) ascorbic acid compound(s) in the composition according to the present invention may range from 3% to 25% by weight, preferably from 5% to 20% by weight, more preferably from 10% to 15% by weight, relative to the total weight of the composition.
[Water]
The composition according to the present invention comprises (e) water.
The (e) water can form an aqueous phase, preferably a continuous aqueous phase, of the composition according to the present invention.
The amount of the (e) water in the composition according to the present invention may be 50% by weight or more, preferably 55% by weight or more, and more preferably 60% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (e) water in the composition according to the present invention may be 90% by weight or less, preferably 85% by weight or less, and more preferably 80% by weight or less, relative to the total weight of the composition.
The amount of (e) water in the composition according to the present invention may range from 50% to 90% by weight, preferably from 55% to 85% by weight, more preferably from 60% to 80% by weight, relative to the total weight of the composition.
[Lipophilic Antioxidant Agent]
The composition according to the present invention may comprise (f) at least one lipophilic antioxidant agent. A single type of lipophilic antioxidant agent may be used, but two or more different types of lipophilic antioxidant agent may be used in combination.
According to the present invention, antioxidant agents are compounds or substances that can scavenge the various radical forms which may be present in the skin; preferably, they simultaneously scavenge all the various radical forms present.
The (f) lipophilic antioxidant agent is different from the (a) retinoid.
The (f) lipophilic antioxidant agent means that the partition coefficient of the antioxidant agent between n-butanol and water is >1, more preferably >10 and even more preferably >100. As the (f) lipophilic antioxidant agents, mention may be made of, phenolic antioxidants which have a hindered phenol structure or a semi-hindered phenol structure within the molecule. As specific examples of such compounds, mention may be made of 3,5-bis(l,l-dimethylethyl)-4-hydroxybenzenepropanoic acid) which has the INCI name of pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate, 2,6-di-tert-butyl-4-methylphenol, 2,6- di-tert-butyl-4-ethylphenol, mono- or di- or tri-(a-methylbenzyl)phenol, 2,2’-methylenebis(4- ethyl-6-tert-butylphenol), 2,2’ -methyl enebis(4-methyl-6-tert-butylphenol), 4,4’- butylidenebis(3-methyl-6-tert-butylphenol), 4,4’-thiobis(3-methyl-6-tert-butylphenol), 2,5-di- tert-butylhydroquinone, 2,5-di-tert-amylhydroquinone, tris[N-(3,5-di-tert-butyl-4- hydroxybenzyl)]isocyanurate, 1 , 1 ,3-tris(2-methyl-4-hydroxy-5-tert-butylphenyl)butane, butylidene-l,lbis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate], octadecyl 3-(3,5-di- tert-butyl-4-hydroxyphenyl)propionate, tetrakis [methylene-3 -(3 ,5-di-tert-butyl-4- hydroxyphenyl)propionato]methane, triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5- methylphenyl)propionate] , 3 ,9-bis {2- [3 -(3 -tert-butyl-4-hydroxy-5 - methylphenyl)propionyloxy]- 1 ,1 -dimethyl ethyl} -2,4,8, 10-tetraoxaspiro [5.5]undecane, 1,3,5- trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 2,2-thiodiethylenebis[3-(3,5- di-tert-butyl-4-hydroxyphenyl)propionate], N,N’-hexamethylenebis(3,5-di-tert-butyl-4- hydroxyhydrocinnamide), 1,6-hexanediol bis[3-(3,5-di-tert-butyl-4- hydroxyphenyl)propionate] , 1 ,3 ,5 -tris [(4-tert-butyl-3 -hydroxy-2, 6-xylyl)methyl] -1,3,5- triazine-2, 4, 6-trione, 2,4-bis(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylanilino)-l,3,5-triazine, 2-tert-butyl-6-(3’-tert-butyl-5 ’-methyl -2 ’-hydroxybenzyl)-4-methylphenyl acrylate, 2-[l-(2- hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 4,6- bis[(octylthio)methyl]-o-cresol, 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate and 1 ,6-hexanediolbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate].
As the (f) lipophilic antioxidant agents, mention may also be made of: BHA (butylated hydroxyl anisole) and BHT (butylated hydroxyl toluene), vitamin E (or tocopherols and tocotrienol) and derivatives thereof, such as the phosphate derivative, for instance TPNA® sold by the company Showa Denko, coenzyme Q10 (or ubiquinone), idebenone, certain carotenoids such as lutein, astaxanthin, beta-carotene, and phenolic acids and derivatives (e. g., chlorogenic acid).
The (f) lipophilic antioxidant agents that may also be mentioned include dithiolanes, for instance asparagusic acid, or derivatives thereof, for instance siliceous dithiolane derivatives, especially such as those described in patent application FR 2 908 769.
The (f) lipophilic antioxidant agents that may also be mentioned include: glutathione and derivatives thereof (GSH and/or GSHOEt), such as glutathione alkyl esters (such as those described in patent applications FR 2 704 754 and FR 2 908 769); cysteine and derivatives thereof, such as N-acetylcysteine or L-2-oxothiazolidine-4-carboxylic acid. Reference may also be made to the cysteine derivatives described in patent applications FR 2 877 004 and FR 2 854 160; certain enzymes for defending against oxidative stress, such as catalase, superoxide dismutase (SOD), lactoperoxidase, glutathione peroxidase and quinone reductases; benzylcyclanones; substituted naphthalenones; pidolates (as described especially in patent application EP 0 511 118); caffeic acid and derivatives thereof, gamma-oryzanol; melatonin, sulforaphane and extracts containing it (excluding cress); the diisopropyl ester of N,N'-bis(benzyl)ethylenediamine-N,N'-diacetic acid, as described especially in patent applications WO 94/11338, FR 2 698 095, FR 2 737 205 or EP 0 755 925; deferoxamine (or desferal) as described in patent application FR 2 825 920. The (f) lipophilic antioxidant agents that may also be used are chaicones, more particularly phloretin or neohesperidin, the diisopropyl ester of N,N'-bis(benzyl)ethylenediamine-N,N'- diacetic acid or an extract of pinaster bark such as PYCNOGENOL®.
As examples of the (f) lipophilic antioxidant agents, mention may also be made of pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate, nordihydroguaiaretic acid, tocopherol, resveratrol, propyl gallate, butylated hydroxyl toluene, butylated hydroxyl anisole, ascorbyl palmitate, tocopherol, and mixtures thereof.
It is preferable that the (f) lipophilic antioxidant agent be biodegradable. In this sense, BHT which is not biodegradable, is not preferable as the (f) lipophilic antioxidant agent. Thus, it is preferable not to use BHT as the (f) lipophilic antioxidant agent. Furthermore, it is preferable that the composition according to the present invention is free from BHT.
The term “free from” here means that the composition according to the present invention may contain a limited amount of BHT. However, it is preferable that the amount of BHT be limited such that it is less than 1% by weight, more preferably less than 0.1% by weight, and even more preferably less than 0.01% by weight, relative to the total weight of the composition. It is most preferable that the composition according to the present invention comprise no BHT.
It is more preferable that the (f) lipophilic antioxidant agent be selected from tocopherol, pentaerythrityl tetra-di-t-butyl hydroxyhydrocinnamate, and a mixture thereof.
The amount of the (f) lipophilic antioxidant agent(s) in the composition according to the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (f) lipophilic antioxidant agent(s) in the composition according to the present invention may be 5% by weight or less, preferably 3% by weight or less, and more preferably 1% by weight or less, relative to the total weight of the composition.
The amount of the (f) lipophilic antioxidant agent(s) in the composition according to the present invention may range from 0.01% to 5% by weight, preferably from 0.05% to 3% by weight, and more preferably from 0.1% to 1% by weight, relative to the total weight of the composition.
[Light Shielding Compound]
The composition according to the present invention may comprise (g) at least one compound which is capable of providing a solution thereof with a transmittance of 10% or less, preferably 5% or less, and more preferably 2% or less, for light with a wavelength of from 290 to 420 nm, along a light path length of 10 mm, wherein the concentration of the (g) compound in the solution is 0.9% by weight relative to the total weight of the solution. Thus, a single type of such a compound or a combination of different types of such compounds may be used.
The (g) compound can provide a low light transmittance. Therefore, the (g) compound may be referred to as a light shielding compound. It is more preferable that the (g) compound be capable of providing a solution with a zero (0) transmittance for light with a wavelength of from 290 to 420 nm along a light path length of 10 mm, wherein the concentration of the (g) compound in the solution is 0.9% by weight relative to the total weight of the solution.
It is even more preferable that the (g) compound be capable of providing a solution with a zero (0) transmittance for light with a wavelength of from 290 to 420 nm along a light path length of 10 mm, wherein the concentration of the (g) compound in the solution is more than 0.1% by weight relative to the total weight of the solution.
The solvent for the solution is not limited as long as the (g) compound is solubilized in the solvent, and the solvent does not have any absorbance for light with a wavelength of from 290 to 420 nm. For example, as the solvent, water and hydrophilic solvents such as ethanol may be used.
The transmittance may be measured by a spectrophotometer, e.g., a UV-Visible/NIR spectrophotometer V-750 by JASCO Corp.
The (g) compound can provide a solution with a transmittance of 10% or less, preferably 5% or less, more preferably 2% or less, and even more preferably zero (0)% for any light with a wavelength of from 290 to 420 nm along a light path length of 10 mm. In other words, the solution of the (g) compound can reduce or shield any light whose wavelength is from 290 nm to 420 nm.
The (g) compound can reduce or shield the light with the above specific wavelength which could reach the (a) retinoid in the composition according to the present invention to cause the decomposition of the (a) retinoid. Therefore, the (g) compound can contribute to enhance the photo-stability of the (a) retinoid, and can reduce the decomposition of the (a) retinoid in the composition according to the present invention.
The (g) compound may be selected from the group consisting of polyphenols.
(Polyphenol)
The expression "polyphenol" is understood to mean a compound containing a plurality of phenolic hydroxyl groups. The phenolic hydroxyl group means a hydroxyl group bonded to an aromatic ring such as a benzene ring and a naphthalene ring. The phenolic hydroxyl group may be optionally etherified or esterified.
The polyphenol may be chosen from those which have an antioxidizing activity.
The polyphenol may be chosen, for example, from flavonoids.
Preferred flavonoids may correspond to general formula (I): in which
A", B", C" and D", independently of one another, represent H, -OH, -R' or -OR', where R' represents the residue of a sugar of formula R'OH;
E" represents H, -OH or -OX', where X' represents:
F", G" and J" represent, independently of one another, H, -OH or -OCH3; and
Xi represents -CH2-, -CO- or -CHOH-, or general formula (II): in which
A', C and D', independently of one another, represent H, -OH, -OCH3, -R' or -OR', where R' represents the residue of a sugar of formula R'OH;
E' represents H, -OH or -OR', where R' represents the residue of a sugar of formula R'OH; and B', F', G' and J', independently of one another, represent H, OH, -OCH3, -OCH2-CH2-OH, or - OR', where R' represents the residue of a sugar of formula R'OH.
Rutinose, glucose, apiose, rhamnose, robinose, neohesperidose, or a combination thereof, may be mentioned among the sugars R'OH.
The compounds of formulae (I) and (II) are known. They can be obtained especially according to the processes described in "The Flavonoids", Harbome J. B., Mabry T. J., Helga Mabry, 1975, pages 1 to 45.
The flavonoids may be selected from flavones, flavonols, isoflavones, flavanols, flavanones, anthocyanidins, and mixtures thereof. Among the flavonoids which can be used for the present invention, mention may be made of taxifolin, catechin, epicatechin, eriodictyol, naringenin, rutin, glucosylrutin, troxerutin, chrysin, tangeretin, luteolin, epigallocatechin and epigallocatechin gallate, quercetin, isoquercetin, fisetin, kaempferol, galangin, gallocatechin and epicatechin gallate.
Certain polyphenols which can be used are present in plants from which they can be extracted in a known way. It is possible to use extracts from tea leaves (Camellia sinensis or Camellia japonica). Mention will in particular be made of the green tea extracts sold under the name SUNPHENON® by the Company Taiyo, which especially contain flavonoids.
As the polyphenol, it is possible to use a mixture of glucosylrutin and rutin sold under the name ALPHA GLUCOSYL RUTIN by the company QINGDAO TAITONG PHARMACEUTICAL.
Among the polyphenols which can be used, mention will also be made of the polyphenols such as camosic acid and camosol which can be extracted, for example, from rosemary, either by extraction followed by distillation (Chang et al., JOSC, Vol. 61, No. 6, June 1984) or by extraction with a polar solvent such as ethanol preceded by extraction using a nonpolar solvent such as hexane to remove the odorant substances, as described in EP- A-307,626.
Polyphenol may also be chosen from (2,5-dihydroxyphenyl)alkylenecarboxylic acids of formula (III) and their derivatives (especially esters and amides): in which
Ri" represents -O-Alk, OH or -N(r')(r"), wherein Aik denotes a linear or branched C1-C20 alkyl, optionally substituted by one or more hydroxyl or alkoxy groups, or a C2-C20 alkenyl, r' and r" independently represent H, C1-C20 alkyl, C2-C6 hydroxyalkyl or C3-C6 polyhydroxyalkyl, or alternatively r' and r" form, together with a nitrogen atom to which they are attached, a heterocycle, r is a number, including zero, such that the -(CH2)r-CORi chain contains at most 21 carbon atoms,
R2" and R3" independently represent H or a C1-C4 alkyl, it additionally being possible for R2" to represent a C1-C4 alkoxy.
The compounds of formula (III) are known or can be prepared according to known methods, for example analogous to those described in patents FR-2,400,358 and FR-2,400,359.
Polyphenol may also be chosen from esters or amides of caffeic acid.
Among the esters of caffeic acid, mention may especially be made of the compounds of formula (IV): in which
Z represents a Ci-Cg alkyl, for example methyl, or the residue of a phytol.
Among the amides of caffeic acid, mention may especially be made of the compounds of formula (V): in which
Z' represents a Ci-C«, in particular Ce-Cs, alkyl.
The compounds of formula (IV) or (V) are known or can be prepared according to known methods.
The amount of the (g) compound(s) in the composition according to the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1%. by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (g) compound(s) in the composition according to the present invention may be 5% by weight or less, preferably 3% by weight or less, and more preferably 1% by weight or less, relative to the total weight of the composition.
The amount of the (g) compound(s) in the composition according to the present invention may range from 0.01% to 5% by weight, preferably from 0.05% to 3% by weight, and more preferably from 0.1% to 1% by weight, relative to the total weight of the composition.
[Chelating Agent]
The composition according to the present invention may comprise (h) at least one chelating agent. A single type of chelating agent may be used, but two or more different types of chelating agents may be used in combination.
As the (h) chelating agent, mention may be made of
(i) aminocarboxylic acids such as the compounds having the following INCI name: diethylenetriaminepentaacetic acid (DTPA), ethylenediaminedisuccinic acid (EDDS) and trisodium ethylenediamine disuccinate such as Octaquest E30 from Octel, ethylenediaminetetraacetic acid (EDTA), ethylenediamine-N,N'-diglutaric acid (EDDG), glycinamide-N,N'-disuccinic acid (GADS), 2-hydroxypropylenediamine- N,N'-disuccinic acid (HPDDS), ethylenediamine-N,N'-bis(ortho- hydroxyphenylacetic acid) (EDDHA), N,N'-bis(2-hydroxybenzyl)ethylenediamine- N,N'-diacetic acid (HBED), nitrilotriacetic acid (NTA), methylglycine diacetic acid (MGDA), N-2-hydroxyethyl-N,N-diacetic acid and glyceryl imino diacetic acid (as described in documents EP-A-317 542 and EP-A-399 133), iminodiacetic acid-N-2- hydroxypropyl sulfonic acid and aspartic acid N-carboxymethyl N-2-hydroxypropyl- 3 -sulfonic acid (as described in EP-A-516 102), beta-alanine-N,N'-diacetic acid, aspartic acid-N,N'-diacetic acid and aspartic acid-N-monoacetic acid (described in EP-A-509 382), chelating agents based on iminodisuccinic acid (IDS A) (as described in EP-A-509 382), ethanoldiglycine acid, phosphonobutane tricarboxylic acid, such as the compound sold by Bayer under the reference Bayhibit AM, tetrasodium glutamate diacetate (GLDA) such as Dissolvine GL38 or 45 S from Akzo Nobel,
(ii) chelating agents based on mono- or polyphosphonic acid, such as the compounds having the following INCI name: diethylenetriaminepenta(methylenephosphonic acid) (DTPMP), ethane- l-hydroxy-l,l,2-triphosphonic acid (E1HTP), [0263]ethane- 2-hydroxy-l,l,2-triphosphonic acid (E2HTP), ethane- l-hydroxy-l,l-diphosphonic acid (EHDP), ethane- 1,1,2-triphosphonic acid (ETP), ethylenediaminetetramethylenephosphonic acid (EDTMP), and hydroxyethane- 1,1- diphosphonic acid (HEDP), and
(iii) chelating agents based on polyphosphoric acid, such as the compounds having the following INCI name: sodium tripolyphosphate (STP), tetrasodium diphosphate, hexametaphosphoric acid, sodium metaphosphate, phytic acid, salts and derivatives thereof, and mixtures thereof.
It is preferable that the (h) chelating agent be biodegradable. In this sense, EDTA which is not biodegradable, is not preferable as the (h) chelating agent. Thus, it is preferable not to use EDTA as the (h) chelating agent. Furthermore, it is preferable that the composition according to the present invention is free from EDTA.
The term “free from” here means that the composition according to the present invention may contain a limited amount of EDTA. However, it is preferable that the amount of EDTA be limited such that it is less than 1% by weight, more preferably less than 0.1% by weight, and even more preferably less than 0.01% by weight, relative to the total weight of the composition. It is most preferable that the composition according to the present invention comprise no EDTA.
It is more preferable that the (h) chelating agent be risodium ethylenediamine disuccinate.
The amount of the (h) chelating agent(s) in the composition according to the present invention may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the (h) chelating agent(s) in the composition according to the present invention may be 3% by weight or less, preferably 2% by weight or less, and more preferably 1% by weight or less, relative to the total weight of the composition.
The amount of the (h) chelating agent(s) in the composition according to the present invention may range from 0.001% to 3% by weight, preferably from 0.005% to 2% by weight, more preferably from 0.01% to 1% by weight, relative to the total weight of the composition.
[Polyol]
The composition according to the present invention may further comprise at least one polyol. A single type of polyol may be used, but two or more different types of polyol may be used in combination.
The term “polyol” here means an alcohol having two or more hydroxy groups, and does not encompass a saccharide or a derivative thereof. The derivative of a saccharide includes a sugar alcohol which is obtained by reducing one or more carbonyl groups of a saccharide, as well as a saccharide or a sugar alcohol in which the hydrogen atom or atoms in one or more hydroxy groups thereof has or have been replaced with at least one substituent such as an alkyl group, a hydroxyalkyl group, an alkoxy group, an acyl group or a carbonyl group.
The polyol may be a C2-C 12 polyol, preferably a C2-C9 polyol, comprising at least 2 hydroxy groups, and preferably 2 to 5 hydroxy groups.
The polyol may be a natural or synthetic polyol. The polyol may have a linear, branched or cyclic molecular structure.
The polyol may be selected from glycerins and derivatives thereof, and glycols and derivatives thereof. The polyol may be selected from the group consisting of glycerin, diglycerin, polyglycerin, ethyleneglycol, diethyleneglycol, propyleneglycol, dipropyleneglycol, butyleneglycol, pentyleneglycol, hexyleneglycol, caprylylglycol, 1,3- propanediol, 1,5-pentanediol, polyethyleneglycol (5 to 50 ethyleneoxide groups), and sugars such as sorbitol.
The amount of the polyol(s) in the composition according to the present invention may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the polyol(s) in the composition according to the present invention may be 20% by weight or less, preferably 15% by weight or less, and more preferably 10% by weight or less, relative to the total weight of the composition.
Thus, the polyol(s) may be present in the composition according to the present invention in an amount ranging from 0.01% to 20% by weight, and preferably from 0.05% to 15% by weight, such as from 0.1% to 10% by weight, relative to the total weight of the composition.
[Other Ingredients]
The composition according to the present invention may contain one or more monoalcohols which are in the form of a liquid at room temperature (25°C), such as for example linear or branched monoalcohols comprising from 1 to 6 carbon atoms, such as ethanol, propanol, butanol, isopropanol, isobutanol, pentanol, and hexanol.
The amount of the monoalcohol(s) in the composition according to the present invention may be 0.01% by weight or more, preferably 0.1% by weight or more, and more preferably 1% by weight or more, relative to the total weight of the composition.
On the other hand, the amount of the monoalcohol(s) in the composition according to the present invention may be 60% by weight or less, preferably 55% by weight or less, and more preferably 50% by weight or less, relative to the total weight of the composition. Thus, the amount of the monoalcohol(s) in the composition according to the present invention may range from 0.01% to 60 by weight, preferably from 0.1% to 55% by weight, and more preferably from 1% to 50% by weight, relative to the total weight of the composition.
The composition according to the present invention may also include various adjuvants conventionally used in cosmetic and dermatological compositions, such as anionic, non-ionic, cationic, and amphoteric or zwitterionic polymers, anionic, cationic, amphoteric, and nonionic surfactants, hydrophilic antioxidants, coloring agents, thickeners, sequestering agents, fragrances, dispersing agents, conditioning agents, film-forming agents, preservatives, copreservatives, and mixtures thereof, except for the ingredients as explained above.
[Preparation]
The composition according to the present invention can be prepared by mixing the essential ingredient(s) as explained above, and optional ingredient(s), if necessary, as explained above.
The method and means to mix the above essential and optional ingredients are not limited. Any conventional method and means can be used to mix the above essential and optional ingredients to prepare the composition according to the present invention.
[Form]
The composition according to the present invention comprises a plurality of capsules and an aqueous phase wherein the capsules are dispersed in the aqueous phase.
The aqueous phase comprises (d) at least one ascorbic acid compound, and (e) water.
The capsule comprises at least one core and at least one shell surrounding the core. It is preferable that the capsule comprises one core and at least one shell surrounding the core.
The shell comprise at least one layer or film. The number of the layer or film is not limited, but it may be preferable that the shell comprises one layer or film.
The core comprises (a) at least one retinoid, and (b) at least one oil. It is preferable that the core further comprises (f) at least one lipophilic antioxidant agent.
The shell comprises (c) at least one polysaccharide;
The (c) polysaccharide can form a capsule which can encapsulate (a) at least one retinoid together with (b) at least one oil, preferably together with (b) at least one oil and (f) at least one lipophilic antioxidant agent. The encapsulation of (a) at least one retinoid can prevent or reduce the contact of (a) at least one retinoid and (d) at least one ascorbic acid compound, and reduce the change in color (in particular, brightness) of the composition according to the present invention. Thus, the capsule can enhance the stability of the composition according to the present invention.
The capsule of (c) at least one polysaccharide including (a) at least one retinoid and (b) at least one oil can be prepared by surrounding or coating a mixture comprising (a) at least one retinoid and (b) at least one oil by (c) at least one polysaccharide. It is preferable that a mixture comprising (a) at least one retinoid, (b) at least one oil, and (f) at least one lipophilic antioxidant agent be surrounded or coated by (c) at least one polysaccharide. It is more preferable that (a) at least one retinoid be solubilized into (b) at least one oil, and then the (b) at least one oil be surrounded or coated by (c) at least one polysaccharide. The (f) at least one lipophilic antioxidant agent may also be solubilized into (b) at least one oil.
The step of preparing or forming a capsule can be performed by any conventional process. For example, it is possible to coextrude (i) a mixture comprising (a) at least one retinoid and (b) at least one oil together with (ii) (c) at least one polysaccharide. In this, case, the excluded (i) mixture can form a core, while the (ii) (c) at least one polysaccharide can form a shell. The coextruded core/shell structure can transform into a core/shell particle which corresponds to the capsule. The above (i) mixture may also include (f) at least one lipophilic antioxidant agent explained below.
The form of the capsule is not limited. For example, the capsule may be in the form of a sphere.
The size of the capsule is not limited. It is possible that the size or the diameter of the capsule may be from 0.1 to 10 mm, preferably from 0.5 to 5 mm, and more preferably from 1 to 3 mm.
The capsule can be dispersed and suspended in the composition according to the present invention. The capsule can provide the composition according to the present invention with unique aspects.
According to the present invention, the capsule includes not only the (a) retinoid but also the (b) oil, and the capsules are dispersed in an aqueous phase including the (d) ascorbic acid compound and (e) water. Therefore, the composition according to the present invention can be in the form of an O/W type.
It is preferable that the composition according to the present invention be in the form of O/W type. It is more preferable that the composition according to the present invention be in the form of an O/W emulsion or an O/W dispersion which comprises fatty phases dispersed in a continuous aqueous phase. The dispersed fatty phases can be oil droplets in the aqueous phase. It is even more preferable that the composition according to the present invention be in the form of an O/W gel emulsion or an O/W gel dispersion. In this case, the aqueous phase may comprise at least one hydrophilic thickener for gelling the aqueous phase.
The O/W architecture or structure, which consists of fatty phases dispersed in an aqueous phase, has an external aqueous phase, and therefore the composition according to the present invention with the O/W architecture or structure can provide a pleasant feeling during use because of the feeling of immediate freshness that the aqueous phase can provide.
The composition according to the present invention may be transparent or translucent, preferably a transparent.
The transparency may be measured by measuring the turbidity (for example, turbidity can be measured with a 2100Q (marketed by HACH) having a round cell (25 mm in diameter and 60 mm height) and a tungsten filament lamp which can emit visible light (between 400 and 800 nm, preferably from 400 to 500 nm). The measurement can be performed on the undiluted composition. The blank may be determined with distilled water. The composition according to the present invention may preferably have a turbidity of less than 200 NTU, preferably less than 150 NTU, more preferably less than 100 NTU, and even more preferably less than 50 NTU.
[Process and Use]
It is preferable that the composition according to the present invention be a cosmetic or dermatological composition, preferably a cosmetic composition, and more preferably a cosmetic composition for a keratin substance such as skin.
The composition according to the present invention can be used for a non-therapeutic process, such as a cosmetic process, for treating a keratin substance such as skin, hair, mucous membranes, nails, eyelashes, eyebrows and/or scalp, by being applied to the keratin substance.
Thus, the present invention also relates to a cosmetic process for treating a keratin substance such as skin, comprising the step of applying the composition according to the present invention to the keratin substance.
The composition according to the present invention may be used as, for example, an antiaging, anti-wrinkling, or turnover promoting product for a keratinous substance such as skin. In particular, the composition according to the present invention may be used as an antiwrinkling skin cosmetic product.
The composition according to the present invention may also be used as, for example, a whitening, an anti-oxidant, or collagen synthesis promoting product for a keratinous substance such as skin. In particular, the composition according to the present invention may be used as a whitening or an anti-oxidant (e.g., for reducing skin damage) cosmetic product.
Another aspect of the present invention may relate to a use of:
(1) a plurality of capsules each of which comprises at least one core, and at least one shell surrounding the core, wherein the core comprises (a) at least one retinoid, and (b) at least one oil, and the shell comprises (c) at least one polysaccharide; in a composition comprising
(2) an aqueous phase comprising (d) at least one ascorbic acid compound, and (e) water, wherein the (1) capsules are dispersed in the (2) aqueous phase for stabilizing the composition, or for reducing the change in color (in particular, brightness) of the composition.
Another aspect of the present invention may also relate to a process for preparing a stable composition comprising (a) at least one retinoid and (d) at least one ascorbic acid compound, or reducing the change in color (in particular, brightness) of a composition comprising (a) at least one retinoid and (d) at least one ascorbic acid compound, comprising the steps of:
(i) forming a plurality of capsules each of which comprises at least one core, and at least one shell surrounding the core, wherein the core comprises the (a) at least one retinoid, and (b) at least one oil, and the shell comprises (c) at least one polysaccharide; and
(ii) dispersing the capsules in an aqueous phase comprising the (d) at least one ascorbic acid compound and (e) water.
The step (i) of forming the capsules may be performed by co-extruding a mixture comprising (a) at least one retinoid and (b) at least one oil, with (c) at least one polysaccharide.
In the above aspects, it is preferable that a mixture of (a) at least one retinoid, (b) at least one oil, and (f) at least one lipophilic antioxidant agent be encapsulated by (c) at least one polysaccharide. Thus, it is preferable that the core further comprises (f) at least one lipophilic antioxidant agent.
The above explanations regarding the ingredients (a) to (f), as well as the optional ingredients, for the composition according to the present invention can apply to those for the above uses and processes according to the present invention. The explanations regarding the preparation and forms of the composition according to the present invention can also apply to those of the composition recited in the above uses and processes.
EXAMPLES
The present invention will be described in more detail by way of examples which however should not be construed as limiting the scope of the present invention.
[Examples 1-2 and Comparative Examples 1-2]
The following compositions according to Examples 1 and 2 in the form of encapsulated O/W gel type emulsions were prepared by mixing the ingredients shown in Table 1.
The preparations of the encapsulated O/W gel type dispersions (Examples 1 and 2) were performed as follows:
(1) mixing the ingredients of Phase A except retinol and heat at 75-80 °C if it includes solid compound to form a uniform mixture, then cool to room temperature and introduce retinol to obtain a uniform mixture of Phase A;
(2) mixing the ingredients of Phase B except ascorbic acid and heart at 75-80 °C to form a uniform mixture, then cooled to room temperature and introduce ascorbic acid to obtain a uniform mixture of Phase B;
(3) mixing the ingredients of Phase C at 80-90 °C to form a uniform mixture of Phase C;
(4) coextruding the uniform mixture of Phase A and the uniform mixture of Phase C by encapsulating the former with the latter to prepare capsules in which the uniform mixture of Phase A is coated and encapsulated with the uniform mixture of Phase C;
(5) adding the capsules to the uniform mixture of Phase B.
Next, each of the compositions according to Examples 1 and 2 was divided into two groups. One group was homogenized by a homogenizer, 15,000 prm for 1 minute to break the capsules therein to prepare the composition according to Comparative Example 1 or 2. The other group was not subjected to the homogenizer to use as the composition according to Example 1 or 2.
The numerical values for the amounts of the components shown in Table 1 are all based on “% by weight” as active raw materials.
Table 1 [Evaluations]
Each of the compositions according to Examples 1-2 and Comparative Examples 1-2 was charged into in a transparent vessel, and stored at 55 °C for 2 weeks. The color (L*a*b* values based on CIE1976) of each composition after the storage was measured by using Konica Minolta CM-3600A.
For Example 1 and Comparative Example 1, the above measurement was performed three times, and the average value and the standard deviation value were calculated for each of L*, a* and b*. The results are shown in Table 1. Then, Student’s t-test was performed. There was a significant difference (p<0.05).
For Example 2 and Comparative Example 2, the above measurement was performed three samples, and the average value and the standard deviation value were calculated for each of L*, a* and b*. The results are shown in Table 1. Then, Student’s t-test was performed. There was a significant difference (p<0.05).
The comparison between Example 1 and Comparative Example 1 demonstrates that the limitation of the contact between retinol and ascorbic acid by encapsulating retinol contributed to improve color stability.
The comparison between Example 2 and Comparative Example 2 also demonstrates that the limitation of the contact between retinol and ascorbic acid by encapsulating retinol contributed to improve color stability.