Aqueous cosmetic composition with ascorbic acid and niacinamide

Abstract

Aqueous cosmetic composition with ascorbic acid and niacinamide The present invention relates to a cosmetic composition comprising - at least 30% by weight, relative to the total weight of the composition, of water, - 12% by weight or less, relative to the total weight of the composition, of ascorbic acid, - 2.5% by weight or less, relative to the total weight of the composition, of a compound chosen from niacinamide and its derivatives, and - optionally at least one base, the pH of the composition being greater than or equal to 3.2, and, when the base is present, the mass ratio between the ascorbic acid and the base is greater than or equal to 4. Figure for abstract: None

Description

Title of the invention: Aqueous cosmetic composition with ascorbic acid and niacinamide

[0001] The present invention relates to an aqueous cosmetic composition, comprising ascorbic acid and niacinamide.

[0002] In cosmetic applications, it is common to add ascorbic acid (vitamin C) as a skin regenerating active ingredient thanks to its properties of stimulating the synthesis of collagen responsible for the firmness of the skin, or as a depigmenting agent, because this vitamin reduces the production of melanin responsible for brown spots. Ascorbic acid is also known for its antioxidant properties.

[0003] However, when ascorbic acid is introduced into an aqueous medium (such as emulsions or serums), its formulation is difficult to achieve, because it destabilizes and changes color drastically. This color change can go as far as a brown coloration, which is prohibitive for the consumer. In addition, the degradation of ascorbic acid can lead to the undesirable formation of carbon dioxide.

[0004] This is why aqueous compositions of the serum or solution type are found on the market, which include ascorbic acid in the form of powder to be solubilized extemporaneously. The disadvantage of this type of product is that vitamin C ends up degrading in the aqueous medium. These products are thus losing their appeal because consumers prefer, for reasons of practicality, serums without prior manipulation, with the guarantee of color stability and without chemical degradation.

[0005] There is therefore a need for an aqueous cosmetic composition comprising ascorbic acid which is stable, i.e. which remains the same color as originally (white or transparent in general) and of the same texture, and which does not degrade the active ingredient, and possibly which does not cause or causes little gas release (preferably carbon dioxide).

[0006] Surprisingly, the Applicant has demonstrated that the addition of a compound chosen from niacinamide and its derivatives in compositions comprising ascorbic acid makes it possible to limit the degradation of the color of said compositions, over time and temperature, while maintaining the stability of the compositions obtained. This limitation of the degradation of the color is possibly coupled with a reduction in the production of gas.

[0007] Thus, the present invention relates to a cosmetic composition comprising:

[0008] - at least 30% by weight, relative to the total weight of composition, of water,

[0009] - 12% by weight or less, relative to the total weight of composition, of as acid corbic,

[0010] - 2.5% by weight or less, relative to the total weight of the composition, of a compound selected from niacinamide and its derivatives, and

[0011] - optionally at least one base,

[0012] the pH of the composition being greater than or equal to 3.2, and, when the base is present, the mass ratio between the ascorbic acid and the base is greater than or equal to 4.

[0013] The composition according to the invention is stable.

[0014] A composition is said to be stable when its macroscopic appearance (clarity and homogeneity) does not change after at least 15 days. In particular, the composition according to the invention has a clear and homogeneous appearance.

[0015] For the purposes of the present invention, the term “clear” means a composition having a transparent appearance.

[0016] For the purposes of the present invention, the term “homogeneous” means a composition consisting of a single phase, in other words monophasic.

[0017] The invention also relates to a cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to the invention.

[0018] Furthermore, the invention also relates to the use of said composition in the cosmetic field, in particular for the care of the skin of the body or face.

[0019] For the purposes of the present invention, keratin materials mean skin.

[0020] By “skin” we mean the skin of the face and / or body, the scalp. Ascorbic acid

[0021] Ascorbic acid within the meaning of the invention preferably corresponds to L-ascorbic acid, or vitamin C. It has the structure of formula (I):

[0022] [Chem.l] HO? HQ ho"

[0023] Preferably, the composition comprises from 0.2% to 12% by weight of ascorbic acid, relative to the total weight of the composition, preferably from 1% to 10% by weight, preferably from 2% to 8% by weight. Niacinamide and its derivatives

[0024] For the purposes of the invention, niacinamide has the following structure:

[0025] [Chem.2]

[0026] By "niacinamide derivative" is preferably meant a compound in which the amide group of the niacinamide is secondary or tertiary, preferably substituted by one or two alkyl groups independently chosen from C1-C4 alkyl groups and / or in which at least one hydrogen atom of the pyridine group is replaced by a C1-C4 alkyl group.

[0027] Preferably, the compound chosen from niacinamide and its derivatives is niacinamide.

[0028] For example, we can cite the product Niacinamide PC® marketed by the company DSM NUTRITIONAL PRODUCTS.

[0029] As shown in examples, surprisingly, the compositions according to the invention exhibit good chemical stability and acceptable color development after 15 days at 45°C thanks to the presence of a compound chosen from niacinamide and its derivatives.

[0030] Preferably, the composition comprises from 0.2% to 2.5% by weight of the compound chosen from niacinamide and its derivatives relative to the total weight of the composition, preferably from 0.5% to 2% by weight, preferentially from 0.8% to 1.5%, more preferentially from 0.9% to 1.1% by weight. Base

[0031] The composition may optionally comprise at least one base.

[0032] The base may be an organic base or a mineral base.

[0033] As an example of an organic base, mention may be made of primary, secondary or tertiary alkylamines, for example triethylamine or butylamine.

[0034] Examples of mineral bases include metal or ammonium hydroxides, such as LiOH, NaOH, KOH, Ca(OH)2, NH4OH, Mg(OH)2 or Zn(OH)2.

[0035] Preferably, the base is chosen from mineral bases, preferably from alkali metal hydroxides, preferably sodium hydroxide or potassium hydroxide, advantageously sodium hydroxide.

[0036] Preferably, when it comprises a base, the composition comprises from 0.01% to 1.5% by weight of base relative to the total weight of composition, preferably from 0.05% to 1.4% by weight, preferably from 0.1% to 1.3% by weight, preferentially from 0.2% to 1.1% by weight.

[0037] Preferably, in the composition according to the invention, when the base is present, the mass ratio between the ascorbic acid and the base ranges from 4 to 40, preferably from 4 to 30, preferably from 4.5 to 20, preferentially from 4.5 to 15. pH of the composition

[0038] The pH of the composition is greater than or equal to 3.2.

[0039] Preferably, the pH of the composition is between 3.2 and 7, preferably between 3.5 and 6.8, preferably between 3.7 and 6.5, preferably between 3.8 and 6.2, more preferably between 4 and 6.

[0040] Such a pH in fact limits the degradation of the color of ascorbic acid, and thus limits the transformation of a colorless composition into a composition which becomes yellow to brown over time. When the pH is strictly lower than 3.2, nia-cinamide and its derivatives do not limit the degradation of the color of ascorbic acid. Aqueous phase

[0041] The composition according to the invention comprises water, the water being included in the aqueous phase.

[0042] The composition according to the invention comprises at least 30% by weight of water relative to the total weight of the composition.

[0043] The water used may be sterile demineralized water and / or floral water such as rose water, cornflower water, chamomile water or lime blossom water, and / or natural thermal or mineral water, such as for example: Vittel water, Vichy basin water, Uriage water, Roche Posay water, La Bourboule water, Enghien-les-Bains water, Saint Gervais-les-Bains water, Néris-les-Bains water, Allevar-les-Bains water, Digne water, Maizières water, Neyrac-les-Bains water, Lons-le-Saunier water, Eaux Bonnes, Rochefort water, Saint Christau water, Fumades water and Tercis-les-bains water, Avène water.

[0044] The composition preferably comprises from 30% to 99.65% by weight of water relative to the total weight of the composition, more preferably from 50% to 98%, even more preferably from 80% to 94% by weight, advantageously from 85% to 89% by weight.

[0045] Preferably, the composition according to the invention is an aqueous solution. Preferably, the composition according to the invention is single-phase. By "single-phase" is meant that the composition according to the invention does not have a dispersed phase (also called a discontinuous phase) in the form of droplets in a dispersing phase (also called a continuous phase). Such a composition may be called a "serum". By "serum" is meant a composition with a fluid, runny texture.

[0046] According to one embodiment, the composition according to the invention is substantially free of silicone oil, preferably substantially free of oil.

[0047] By "substantially free of silicone oil" is meant that the composition according to the invention has a silicone oil content of less than or equal to 2% by weight, relative to the total weight of the composition, preferably less than or equal to 0.5% by weight, preferentially less than or equal to 0.1% by weight, more preferentially between 0.01 and 2% by weight. Preferably, the composition according to the invention is completely free of silicone oil.

[0048] Silicone oil is understood to mean a fatty substance in liquid form at room temperature (20 to 25°C) and at atmospheric pressure (760 mm Hg), and comprising at least one Si atom.

[0049] Examples of silicone oils that may be mentioned include cyclomethicone or polydimethylsiloxanes.

[0050] By "substantially oil-free" is meant that the composition according to the invention has an oil content of less than or equal to 2% by weight, relative to the total weight of the composition, preferably less than or equal to 0.5% by weight, preferentially less than or equal to 0.1% by weight, more preferentially between 0.01 and 2% by weight. Preferably, the composition according to the invention is completely oil-free.

[0051] Oil is understood to mean a fatty substance in liquid form at room temperature (20 to 25°C) and at atmospheric pressure (760 mm Hg). The "fatty substance" comprises at least one "fatty" hydrocarbon chain, i.e. a linear hydrocarbon chain of at least 4 carbon atoms, unsaturated or unsaturated, optionally substituted, and in particular a linear C5-C30 hydrocarbon chain.

[0052] As oil, mention may be made of mineral oils (paraffin); vegetable oils (sweet almond oil, macadamia oil, blackcurrant seed oil, jojoba oil); synthetic oils such as perhydrosqualene, alcohols, fatty acids or esters such as C12-C15 alcohol benzoate or such as perhydrosqualene, alcohols, fatty acids or esters such as C12-C15 alcohol benzoate, octyl palmitate, isopropyl lanolate, triglycerides including those of capric / caprylic acids, oxyethylenated or oxypropylenated fatty esters and ethers; silicone oils (cyclomethicone, polydimethylsiloxanes or PDMS) or fluorinated, polyalkylenes.

[0053] According to one embodiment, the composition according to the invention is substantially free of hyaluronic acid and / or one of its salts.

[0054] By "substantially free of hyaluronic acid and / or one of its salts" is meant that the composition according to the invention has a content of hyaluronic acid and / or one of its salts, less than or equal to 1% by weight, relative to the total weight of the composition, preferably less than or equal to 0.5% by weight, preferentially less than or equal to 0.1% by weight, more preferentially between 0.01 and 1% by weight. Preferably, the composition according to the invention is completely free hyaluronic acid and / or one of its salts.

[0055] Hyaluronic acid is a linear, non-sulfated glycosaminoglycan composed of repeating units of D-glucuronic acid and N-acetyl-D-glucosamine.

[0056] The hyaluronic acid may have a number average molecular weight ranging from 500 Da to 10 MDa, and more particularly ranging from 2 KDa to 2 MDa, or be a low molecular weight hyaluronic acid and have a number average molecular weight of approximately 50 kDa.

[0057] Among the hyaluronic acid salts, mention may in particular be made of sodium salts, potassium salts, zinc salts, silver salts, and mixtures thereof. More particularly, as hyaluronic acid salts, mention may be made of potassium hyaluronate and sodium hyaluronate, preferably sodium hyaluronate.

[0058] According to one embodiment, the composition according to the invention is substantially free of surfactants. By "substantially free of surfactants" is meant that the composition according to the invention has a surfactant content of less than or equal to 2% by weight, relative to the total weight of the composition, preferably less than or equal to 1% by weight, preferentially between 0.01% and 2% by weight. The surfactants may preferably be peptizers, the concentration of which is between 0.01 and 2% by weight; they allow the solubilization of a small quantity of oil(s) or lipophilic compounds or perfume(s) (i.e. concentration of perfume(s) or oil(s) or lipophilic compound(s) between 0.05% and 2%). Preferably, the composition according to the invention is completely free of surfactant.

[0059] According to one embodiment, the composition according to the invention is substantially free of water-soluble organic solvent.

[0060] By "substantially free of water-soluble organic solvent" is meant that the composition according to the invention has a water-soluble organic solvent content of less than or equal to 5% by weight, relative to the total weight of the composition, preferably less than or equal to 0.5% by weight, preferentially less than or equal to 0.1% by weight, more preferentially between 0.01 and 5% by weight. Preferably, the composition according to the invention is completely free of water-soluble organic solvent.

[0061] According to another embodiment, the composition according to the invention comprises at least one water-soluble organic solvent.

[0062] Preferably, by water-soluble organic solvent is meant organic solvents chosen from alcohols, polyols and their mixtures.

[0063] Among the alcohols, mention may be made of C1-C10 alcohols, more preferably C1-C5, such as ethanol, isopropanol, propanol and butanol.

[0064] The polyol may be chosen from polyols having from 2 to 20 carbon atoms, such as glycerol, diglycerol, propylene glycol, isoprene glycol, dipropylene glycol, butylene glycol, hexylene glycol, 1,3-propanediol, pentylene glycol, polyethylene glycols having 2 to 200 ethylene oxide units and mixtures thereof.

[0065] The composition may also comprise one or more additive(s) conventionally used in cosmetic compositions, preferably chosen from active ingredients, preservatives and perfumes.

[0066] Preferably, among the active agents that can be used, adenosine, salicylic acid or glycolic acid are preferred.

[0067] The composition according to the invention may comprise at least one preservative.

[0068] Among the preferred preservatives, mention may be made of hydroxyacetophenone, phenoxyethanol and their mixtures.

[0069] Preferably, the composition according to the invention comprises from 0.1% to 2% by weight, preferably from 0.3% to 1.5% by weight, more preferably from 0.5% to 1% by weight of preservative(s) relative to the total weight of the composition.

[0070] Preferably, the composition of the present invention is transparent.

[0071] For the purposes of the present invention, the term "transparent composition" means a composition having a turbidity value of less than 20 NTU, preferably less than 15 NTU, preferably less than 10 NTU. Preferably, the turbidity of the compositions is at least equal to 1 NTU.

[0072] NTU (nephelometric turbidity units) are the units of measurement for the turbidity of a composition. Turbidity measurement is carried out, for example, with a Hach Company model 2100P turbidimeter, the tubes used for the measurement being referenced AR397A cat 24347-06. Measurements are carried out at room temperature (20°C to 25°C).

[0073] Preferably, the composition is transparent and has a turbidity value of between 1 and 20 NTU, preferably between 1 and 15 NTU, preferably less than 10 NTU.

[0074] The expressions “between ... and ...” and “ranging from ... to ...” must be understood inclusively, unless otherwise specified.

[0075] Concrete, but in no way limiting, examples illustrating the invention will now be given. The quantities indicated are in % by weight of raw materials relative to the total weight of the composition, unless otherwise stated. EXAMPLES

[0076] Example 1: Preparation of the compositions according to the invention and of comparative compositions and evaluation of their stability over time

[0077] The aqueous solutions (water: Qsp 100) C1 to C4 according to the invention, and the comparative compositions C5* to C13*, are listed in Tables 1 to 3 below. Each composition is prepared in two copies in order to study their aging at room temperature and at 45°C.

[0078] The compositions are then stored at room temperature or at 45°C. Their color was evaluated after 15 days (15d TA) or 2 months at room temperature (2M TA) and after 15 days (15d 45°C) or 2 months at 45°C (2M 45°C).

[0079] Their color is rated on a scale of 0 to 9, with 0 representing a transparent composition, and 9 representing a dark brown composition, with the intermediate grades representing increasingly darker shades of yellow and then orange.

[0080] The formation of gas, an indicator of the degradation of vitamin C (decarboxylation which produces CO2), was also evaluated after 15 days or 2 months at 45°C. For this, the compositions are stored in bottles sealed with an extensible plastic teat. Carbon dioxide is released at the top of the bottle. Since the teat of the pipette is elastic, the liquid pushed by the gas rises in the pipette and causes the teat to swell until it explodes.

[0081] The evaluation of the degassing is therefore carried out in a first measurement according to the height reached by the liquid in the pipette. If the liquid rises beyond the cap, the degassing is evaluated in a second measurement according to the size of the teat. Since the photos are standardized, it is possible to qualify the gas release objectively by means of a score on a scale of 1 to 9, 9 representing the bursting of the teat. The higher the score, the greater the degradation.

[0082] [Tables 1] Composition Color Gas release Vitamin C (%w / w) Niacinamide (%w / w) NaOH (%w / p) Vit C / NaOH ratio PH 2M TA 2M 45°C 2M 45°C Cl 1 1.05 - - 4 1.5 3 1 C5* 1 - 0.09 11.1 4 2 4.5 1.5

[0083] [Tables2] Composition Color Gaseous release Vitamin C (%w / w) Niacinamide (%w / w) NaOH (%w / p) Vit C / NaOH ratio PH 15d TA 15d 45°C 15d 45°C C2 5 1 0.38 13.2 4 0.5 1.5 3.5 C6* 5 - 0.506 9.9 4 1 2.5 5 C3 5 1 1.108 4.5 6 1.5 2 1 C7* 5 - 1.108 4.5 6 1.5 2.5 2 C4 10 1 0.728 13.7 4 1.5 3 7 C8* 10 - 1.04 9.6 4 1 5 7

[0084] Compositions C1 to C4 according to the invention have a lower coloration than their respective comparative compositions C5* to C8*, which do not comprise niacinamide. Compositions C1 to C3 also have a lower gas release than their respective comparative compositions C5* to C7*.

[0085] [Tables3] Composition Color Gaseous release Vitamin C (%w / w) Niacinamide (%w / w) NaOH (%w / p) Vit C / NaOH ratio PH 15d TA 15d 45°C 15d 45°C C9* 1 1 0.28 3.5 6 2 3 0.5 CIO* 1 - 0.225 4.4 6 2.5 1.5 0.5 Eyelash* 10 1 - - 3 1.5 3 7 C12* 10 - 0.144 69.4 3 0.5 2.5 7 C13* 10 10 - - 4 3 5 7 C8* 10 - 1.04 9.6 4 1 5 7

[0086] Although comprising niacinamide, the comparative compositions C9* and Cil*, whose vitamin C / NaOH mass ratio and / or pH are outside the invention, do not exhibit less significant coloration than the corresponding comparative compositions CIO* and C12* (free of niacinamide).

[0087] In addition, the comparative composition C13* comprising a niacinamide content outside the range according to the invention, does not present a less significant coloration than the corresponding comparative composition C8* (free from niacinamide).

Claims

Claims

1. Cosmetic composition comprising: - at least 30% by weight, relative to the total weight of the composition, of water, - 12% by weight or less, relative to the total weight of the composition, of ascorbic acid, - 2.5% by weight or less, relative to the total weight of the composition, of a compound chosen from niacinamide and its derivatives, the niacinamide derivative being a compound in which the amide group of the niacinamide is substituted by one or two alkyl groups independently chosen from C1-C4 alkyl groups and / or in which at least one hydrogen atom of the pyridine group is replaced by a C1-C4 alkyl group, and - at least one base, the pH of the composition being greater than or equal to 3.2, and the mass ratio between the ascorbic acid and the base ranging from 4 to 40.

2. Composition according to claim 1, characterized in that it comprises from 0.2% to 12% by weight of ascorbic acid, relative to the total weight of the composition, preferably from 1% to 10% by weight, preferably from 2% to 8% by weight.

3. Composition according to claim 1 or 2, characterized in that it comprises from 0.2% to 2.5% by weight of the compound chosen from niacinamide and its derivatives, the niacinamide derivative being a compound in which the amide group of the niacinamide is substituted by one or two alkyl groups independently chosen from C1-C4 alkyl groups and / or in which at least one hydrogen atom of the pyridine group is replaced by a C1-C4 alkyl group, relative to the total weight of the composition, preferably from 0.5% to 2% by weight, preferably from 0.8% to 1.5%, more preferably from 0.9% to 1.1% by weight.

4. Composition according to any one of claims 1 to 3, characterized in that the base content ranges from 0.01% to 1.5% by weight of base relative to the total weight of composition, preferably from 0.05% to 1.4% by weight, preferably from 0.1% to 1.3% by weight, preferentially from 0.2% to 1.1% by weight.

5. Composition according to any one of claims 1 to 4, characterized in that the mass ratio between the ascorbic acid and the base ranges from 4 to 30, preferably from 4.5 to 20, preferably from 4.5 to 15.

6. Composition according to one of claims 1 to 5, characterized in that the compound chosen from niacinamide and its derivatives is nia-cinamide.

7. Composition according to one of claims 1 to 6, characterized in that the base is chosen from mineral bases, preferably from alkali metal hydroxides, preferably sodium hydroxide or potassium hydroxide.

8. Composition according to one of claims 1 to 7, characterized in that the pH of the composition is between 3.2 and 7, preferably between 3.5 and 6.8, preferably between 3.7 and 6.5, preferably between 3.8 and 6.2, more preferably between 4 and 6.

9. Composition according to one of claims 1 to 8, characterized in that it comprises from 30% to 99.65% by weight of water relative to the total weight of the composition, more preferably from 50% to 98%, even more preferably from 80% to 94% by weight, advantageously from 85% to 89% by weight.

10. Composition according to one of claims 1 to 9, characterized in that it is substantially free of silicone oil, preferably substantially free of oil, and / or substantially free of hyaluronic acid and / or one of its salts, and / or substantially free of surfactant.

11. Cosmetic process for caring for keratin materials, preferably the skin, comprising the application to said keratin materials of a composition according to one of claims 1 to 10.

12. Cosmetic use of a composition according to one of claims 1 to 10, for the care of the skin of the body or face.