SKIN SCRUB COMPOSITIONS

Abstract

SKIN SCRUB COMPOSITIONS The present invention relates to compositions comprising water, monoalcohol, alpha-hydroxy acid, beta-hydroxy acid, and polyhydroxy acid, and optionally a humectant, as well as methods for using and preparing such compositions. Figure for the abstract: none

Description

Title of the invention: SKIN SCRUB COMPOSITIONS FIELD OF INVENTION

[0001] The present invention relates to compositions comprising water, monoalcohol, alpha-hydroxy acids, beta-hydroxy acids, and polyhydroxy acids, as well as methods for using and producing such compositions. The compositions have one or more beneficial attributes, including, for example, the fact that they contain solubilized beta-hydroxy acids, that they are well tolerated during use, that they exfoliate at various levels of the skin, that they do not need to be neutralized after application to the skin, and / or that they are suitable for use by a consumer at home. DISCUSSION OF THE CONTEXT

[0002] Conventional skin exfoliation procedures include mechanical removal, for example, dermabrasion or CO2 laser, and chemically induced skin removal. Chemical skin exfoliation techniques are currently very popular and are often categorized according to the degree or amount of skin removal achieved.

[0003] Chemical scrubs can be classified as superficial, medium, and deep chemical scrubs, depending on the depth of the chemical damage to the skin that occurs. Superficial chemical scrubs are those that remove or effect accelerated replacement or renewal of the epidermis. Medium-depth scrubs penetrate the papillary dermis. Deep scrubs penetrate the reticular dermis. WO 97 / 28786 reports that chemical scrubbing agents include α-hydroxy acids, for example, glycolic acid or other "fruit acids" such as citric and lactic acids; trichloroacetic acid; phenol; resorcinol; and Jessner's solution, an ethanol solution containing equal parts (approximately 14%) of resorcinol, salicylic acid, and lactic acid (85%).

[0004] As a general rule, it is possible to solubilize salicylic acid in certain ingredients such as some surfactants and oils. However, the presence of such compounds in a skin scrub composition may negatively impact the application and sensory properties of the composition.

[0005] Furthermore, it is possible to solubilize salicylic acid in basic aqueous compositions (pH >7) by the formation of a corresponding salicylate. However, in an acidic formulation, salicylic acid tends to precipitate (not solubilize).

[0006] Finally, it is also possible to solubilize smaller quantities of salicylic acid in large quantities of ethanol. However, large quantities of ethanol may negatively impact the sensory and application properties of the composition.

[0007] Potentially relevant publications include: • US 2022 / 0362121 relates to a personal care product containing an alpha-hydroxy acid; a beta-hydroxy acid; and a polyhydroxy acid, wherein the personal care formulation has a weight ratio of alpha-hydroxy acid to polyhydroxy acid of about 5:1 to about 1:4, and wherein the personal care formulation has a weight ratio of beta-hydroxy acid to polyhydroxy acid of about 1:1 to about 1:11. • US 2008 / 0146259 relates to skin scrub compositions containing salicylic acid derivatives.

[0008] There remains a need in the art of improved skin scrub compositions, in particular compositions which can be used at home by a consumer, which have good application properties while maintaining the solubility of salicylic acid.

[0009] Accordingly, one aspect of the present invention is a skin scrub composition, in particular a composition that can be used at home by a consumer, which has good properties with regard to the ease of composition and / or the comfort of application of the composition, as well as solubilized salicylic acid. Summary of the invention

[0010] The present invention relates to skin scrub compositions comprising water, monoalcohol, alpha-hydroxy acid, beta-hydroxy acid and polyhydroxy acid. Preferably, the composition further comprises at least one humectant.

[0011] The present invention also relates to skin scrub compositions comprising (a) water, preferably in an amount of 50% or less by weight; (b) 5% to 30% by weight of a monoalcohol, preferably ethanol, wherein the amount of water in the composition is greater than the amount of monoalcohol in the composition; (c) 10% to 50% by weight of an alpha-hydroxy acid, preferably a combination of alpha-hydroxy acids including lactic acid, glycolic acid, and mandelic acid; (d) 1% to 3% by weight of a beta-hydroxy acid, preferably salicylic acid; and (e) 1% to 10% by weight of a polyhydroxy acid, preferably gluconolactone, all weights being relative to the total weight of the composition. Preferably, the composition further comprises at least one humectant. in an amount exceeding approximately 5% by weight relative to the total weight of the composition. Preferably also, the pH of the composition is less than 4.

[0012] The present invention also relates to skin exfoliation methods comprising applying compositions of the present invention to the skin in sufficient quantity to exfoliate the skin. Preferably, the skin exfoliation methods are performed by a consumer and not by a skincare professional using compositions of the present invention.

[0013] The present invention also relates to methods for treating skin showing signs of aging, preferably wrinkles and / or fine lines, comprising applying compositions of the present invention to the skin showing signs of aging in a sufficient quantity to treat the signs of aging. Preferably, the methods for treating skin showing signs of aging are performed by a consumer and not by a skincare professional using compositions of the present invention.

[0014] The present invention also relates to methods for smoothing skin texture, preferably skin irregularities resulting from acne, comprising applying compositions of the present invention to the skin in sufficient quantity to make the skin texture more uniform (smoother). Preferably, the skin texture smoothing methods are performed by a consumer and not by a skincare professional using compositions of the present invention.

[0015] It must be understood that both the preceding general description and the detailed description that follows are provided by way of example and explanation only, and do not limit the invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] In the following description of the invention and the claims annexed thereto, it shall be understood that the terms used have their ordinary and usual meanings in the art, unless otherwise specified.

[0017] “Approximately” as used here means to within 10% of the number indicated (for example, “ "Approximately 10%" means from 9% to 11% and "approximately 2%" means from 1.8% to 2.2%.

[0018] “At least one” means one or more and thus includes components individual products as well as mixtures / combinations.

[0019] As used here, all proposed ranges are intended to include each specific range within the given ranges, and all combinations of intermediate sub-ranges. Thus, a range from 1 to 5 specifically includes 1, 2, 3, 4 and 5, as well as sub-ranges such as 2 to 5, 3 to 5, 2 to 3, 2 to 4, 1 to 4, etc.

[0020] “Substituted” as used herein means comprising at least one substitute. Non-limiting examples of substituents include atoms, such as oxygen and nitrogen atoms, as well as functional groups, such as hydroxyl groups, ether groups, alkoxy groups, acyloxyalkyl groups, oxyalkylene groups, polyoxyalkylene groups, carboxylic acid groups, amine groups, acylamino groups, amide groups, halogen-containing groups, ester groups, thiol groups, sulfonate groups, thiosulfate groups, siloxane groups, and polysiloxane groups. The substituent(s) may also be substituted.

[0021] “Physiologically acceptable” means compatible with the skin and having a color, odor, and feel that are pleasant and acceptable, and that do not cause unacceptable discomfort likely to discourage a consumer from using the composition. Acceptable pH levels for the compositions of the present invention are acidic, namely, less than 7, preferably 6 or less, preferably 5 or less, preferably 4 or less, including all intermediate ranges and sub-ranges, such as, for example, 3 to 5, 4 to 6, 2 to 4, 3 to 4, etc.

[0022] “Natural compound” means any compound derived directly from a natural substance such as a plant without having undergone any chemical modification.

[0023] “Compound of natural origin” means any compound derived from a a natural compound that has undergone one or more chemical modifications, for example by organic synthesis reaction, without the properties of the natural compound being modified.

[0024] “Synthetic compound” means any compound that is not a compound natural nor a compound of natural origin.

[0025] “Room temperature” means 25 °C.

[0026] “Atmospheric pressure” means 760 mmHg, i.e. 105 pascals.

[0027] The compositions and methods of the present invention may include, consist of, or essentially consist of the essential elements and limitations of the invention described herein, as well as any additional or optional ingredient, component, or limitation described herein or otherwise useful. For example, the solvent system may "consist essentially of" water and a C2-C4 monoalcohol, or "consist essentially of water, a C2-C4 monoalcohol, and a humectant such as a glycol or a polyol."

[0028] For the purposes of the present invention, the "fundamental and novel property" associated with compositions, components and processes which "consist essentially of" identified ingredients or actions is the "solubility of beta-hydroxy acid (BHA)".

[0029] “Exempt” or “substantially exempt” or “devoid of” as used herein means that although it is preferable that no quantity of the specific component be present in the composition, it is possible that there may be very small quantities of it in the compositions of the invention, provided that these quantities do not materially affect at least one, preferably most, of the advantageous properties of the packaging compositions of the invention. Thus, for example, "free from botanical extracts" means that an effective quantity (i.e., greater than trace amounts) of botanical extracts is omitted from the composition (i.e., about 0% by weight), "substantially free from botanical extracts" means that botanical extracts are present in quantities not exceeding 0.1% by weight, and "devoid of botanical extracts" means that botanical extracts are present in quantities not exceeding 0.25% by weight, relative to the total weight of the composition.The term "botanical extract" includes witch hazel, and compositions may also be "free of", "substantially free of", and "devoid of" witch hazel.

[0030] The same nomenclature applies to all other ingredients identified throughout the application and in the preceding paragraph, such as, for example, oils and / or waxes, and surfactants (the compositions of the invention that are "free of oils and / or waxes," "substantially free of oils and / or waxes," and "devoid of oils and / or waxes," and / or "free of surfactants," "substantially free of surfactants," and "devoid of surfactants" have meanings consistent with the discussion in the preceding paragraph), even if this is not specifically mentioned for each identified ingredient. The examples of the use of such language, such as those in this paragraph and the preceding paragraph, are intended to be examples of embodiments of the present invention, and not limitations.

[0031] Reference is made herein to trade names of materials including, but not limited to, polymers and optional components. The inventors herein do not intend to limit themselves to the materials described and referenced by a particular trade name. Equivalent materials (for example, those obtained from a different source under a different name or catalogue (reference) number) to those referenced by a trade name may be substituted and used in the processes described and claimed herein.

[0032] Unless otherwise stated, all percentages and ratios are calculated by weight. Unless otherwise stated, all percentages are calculated on the basis of the total weight of a composition. All component or composition levels refer to the active level of that component or composition and are understood to exclude impurities, for example, residual solvents or by-products, which may be present in commercially available sources. Alpha-hydroxy acids (AHAs)

[0033] According to the present invention, compositions comprising at least one AHA are proposed. AHAs are known in the art, representative examples of which include citric acid, gluconic acid, glycolic acid, lactic acid, malic acid, mandelic acid, tartaric acid, etc.

[0034] According to preferred embodiments, the compositions of the present invention include more than one AHA. Preferably, the compositions of the present invention containing more than one AHA include mandelic acid. The more preferred compositions contain glycolic acid and lactic acid in addition to mandelic acid.

[0035] Preferably, at least one AHA is present in the compositions of the present invention in a total (combined) amount ranging from about 7.5% to about 60% by weight, preferably from about 10% to about 50% by weight, preferably from about 15% to about 40%, and preferably from about 20% to about 30% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 11% to 40%, 20% to 25%, 15% to 25%, etc.

[0036] Preferably, if mandelic acid is present, it is present in the compositions of the present invention in an amount ranging from about 0.5% to about 25% by weight, preferably from about 1% to about 20% by weight, preferably from about 1% to about 10%, and preferably from about 1% to about 5% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 11% to 20%, 20% to 25%, 15% to 25%, 1% to 3%, etc.

[0037] Preferably, if glycolic acid is present, it is present in the compositions of the present invention in an amount ranging from about 2.5% to about 20% by weight, preferably from about 5% to about 15% by weight, preferably from about 6% to about 12.5%, and preferably from about 7% to about 10% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 11% to 20%, 10% to 15%, 12.5% ​​to 15%, 5% to 10%, etc.

[0038] Preferably, if lactic acid is present, it is present in the compositions of the present invention in an amount ranging from about 2.5% to about 20% by weight, preferably from about 5% to about 15% by weight, preferably from about 6% to about 12.5%, and preferably from about 7% to about 10% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 11% to 20%, 10% to 15%, 12.5% ​​to 15%, 5% to 10%, etc. Beta-hydroxy acids (BHA)

[0039] According to the present invention, compositions comprising at least one BHA are proposed. BHAs are known in the art, representative examples of which include salicylic acid, beta-hydroxybutanoic acid, tropic acid, and trethomechanical. Preferably, the compositions of the present invention comprise salicylic acid.

[0040] Preferably, at least one BHA is present in the compositions of the present invention in an amount ranging from about 0.5% to about 5% by weight, preferably from about 1% to about 3% by weight, preferably from more (or greater than) 1% to about 3%, and preferably from more than 1% to about 2% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 1.25% to 2%, 1.3% to 2%, 1.5% to 2%, etc.

[0041] According to preferred embodiments, the AHA(s) and the BHA(s) are present in the compositions of the present invention in a weight ratio of about 15:1 to about 3:1, preferably about 12:1 to about 5:1, and preferably about 11:1 to about 7:1, including all intermediate ranges and sub-ranges.

[0042] According to preferred embodiments, wherein salicylic acid and mandelic acid are present in the compositions of the present invention, salicylic acid and mandelic acid are present in the compositions of the present invention in a weight ratio of approximately 1:10 to approximately 4:1, preferably approximately 1:5 to approximately 3:1, and preferably approximately 1:1 to approximately 2:1, including all intermediate ranges and sub-ranges. According to some of these preferred embodiments, more salicylic acid is present in the compositions than mandelic acid. Polyhydroxy acids (PHAs)

[0043] According to the present invention, compositions comprising at least one PHA are proposed. PHAs are known in the art, representative examples of which include gluconolactone, galactose, and lactobionic acid. Preferably, the compositions of the present invention comprise gluconolactone.

[0044] Preferably, at least one PHA is present in the compositions of the present invention in an amount ranging from about 0.5% to about 25% by weight, preferably from about 1% to about 20% by weight, preferably from about 1% to about 10%, and preferably from about 5% to about 10% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 4% to 14%, 1% to 15%, 5% to 25%, etc.

[0045] According to preferred embodiments, the AHA(s) and the PHA(s) are present in the compositions of the present invention in a weight ratio of about 25:1 to about 1:1, preferably about 12:1 to about 2:1, and preferably about 6:1 to about 2.5:1, including all intermediate ranges and sub-ranges.

[0046] According to preferred embodiments, the PHA(s) and the BHA(s) are present in the compositions of the present invention in a weight ratio of approximately 15:1 to about 1:1, preferably about 10:1 to about 2:1, and preferably about 6:1 to about 2.5:1, including all intermediate ranges and sub-ranges.

[0047] According to preferred embodiments, in which gluconolactone and mandelic acid are present in the compositions of the present invention, gluconolactone and mandelic acid are present in the compositions of the present invention in a weight ratio of approximately 1:10 to approximately 10:1, preferably from approximately 1:5 to approximately 5:1, and preferably from approximately 5:1 to approximately 2:1, including all intermediate ranges and sub-ranges. According to some of these preferred embodiments, more gluconolactone is present in the compositions than mandelic acid. Water / mono-alcohol

[0048] According to the present invention, compositions comprising an aqueous phase solvent system comprising (i) water in an amount of at least about 5% by weight relative to the total weight of the composition; and (ii) at least one C2-C4 monoalcohol are proposed.

[0049] According to the present invention, the compositions comprise water. Preferably, the compositions comprise from about 10% to about 50% water by weight, preferably from about 15% to about 50%, preferably from about 20% to about 50%, preferably from about 25% to about 45%, and preferably from about 30% to about 45% water by weight, all weights being based on the total weight of the composition, including all intermediate ranges and sub-ranges, such as, for example, about 25% to less than 50%.

[0050] According to the present invention, the compositions comprise at least one monoalcohol. Suitable C2-C4 monoalcohols include, for example, ethanol, propanol, butanol, isopropanol, and isobutanol. Ethanol is particularly preferred.

[0051] Preferably, the C2-C4 monoalcohol(s) are present in the compositions of the present invention in an amount ranging from about 1% to about 30%, preferably from about 2.5% to about 30%, preferably from about 5% to about 30%, and preferably from about 10% to about 25%, by weight, all weights being based on the total weight of the composition, including all intermediate ranges and sub-ranges such as, for example, about 10% to about 30%.

[0052] Preferably, more water is present in the compositions of the present invention than C2-C4 monoalcohol.

[0053] Preferably, the aqueous solvent system of the compositions of the present invention consists essentially of, or consists of, water and one or more C2-C4 monoalcohols. Preferably, the aqueous solvent system is "free of", "devoid of", or "substantially free of" solvents other than water and the C2-C4 monoalcohol(s). Humectant

[0054] According to preferred embodiments, the compositions of the present invention further optionally comprise at least one humectant. Preferably, the at least one humectant comprises at least one hydroxy group or is a derivative of a compound comprising at least one hydroxy group. Suitable humectants of this type are known in the art and include, but are not limited to, propylene glycol, butylene glycol, hexylene glycol, glycerin (sometimes called glycerol or glycerin), and glucose ethers. Preferably, the at least one humectant is selected from glycerin, propylene glycol, butylene glycol, and mixtures thereof.

[0055] Where appropriate, at least one humectant is present in the compositions of the present invention in an amount ranging from about 0.5% to about 25% by weight, preferably from about 1% to about 20% by weight, preferably from about 2.5% to about 15%, and preferably from about 5% to about 10% by weight relative to the weight of the composition, including all intermediate ranges and sub-ranges such as, for example, 1% to 10%, 5% to 15%, 15% to 25%, 1% to 5%, etc.

[0056] However, according to certain embodiments, the compositions of the present invention are "free", "substantially free" or "devoid" of humectant. Optional additional ingredients

[0057] The composition of the invention may also include any additive commonly used in the field concerned. For example, film-forming agents, gelling agents, surfactants, oils, waxes, botanical extracts, dispersants, preservatives, perfumes, fillers, antioxidants, neutralizing agents, silicone elastomers, and mixtures thereof may be added. A non-exhaustive list of these ingredients can be found in US patent application publication No. 2004 / 0170586. Other examples of suitable additional components can be found in other references. Still other examples of these additional ingredients can be found in the International Cosmetic Ingredient Dictionary and Handbook (9th ed. 2002).However, it should be understood that preferred embodiments of the present invention include compositions that are "free", "substantially free" or "devoid" of the ingredients mentioned in this paragraph such as oils, waxes, surfactants, botanical extracts, etc.

[0058] A person skilled in the art shall ensure that the optional additional additives and / or their quantity are selected so that the advantageous properties of the composition according to the invention are not, or substantially not, compromised by the envisaged addition.

[0059] These substances can be selected in various ways by a person skilled in the art in order to prepare a composition which has the desired properties, for example, consistency or texture.

[0060] It goes without saying that the composition of the invention must be cosmetically or dermatologically acceptable, that is to say, it must contain a physiologically acceptable non-toxic medium.

[0061] The skin-scrubbing compositions of the present invention can be applied in any manner whatsoever, for example, by wiping, distribution, etc. (hereinafter referred to as "application"). For example, the application of the compositions of the invention can be carried out manually, for example, using one or more fingers, using an absorbent cotton pad soaked in the concentrated solution, using a sable brush soaked in the solution, by gently wiping with an absorbent fibrous material soaked in the solution such as a square of gauze or a non-woven pad, etc.Preferably, (1) the compositions of the present invention are applied by a consumer, and not by a skin care professional, preferably on the consumer's own premises; (2) the compositions of the present invention are applied using one or more fingers; and / or (3) areas such as the eyes and lips are avoided during the application of the skin scrub composition of the present invention.

[0062] The applied compound or composition is generally allowed to air dry for a relatively short period, preferably 20 minutes or less, and preferably 15 minutes or less, with approximately 15 minutes being preferred. A single, uniform application of the composition to the skin to be treated and / or its surroundings is generally sufficient.

[0063] Once the applied composition has been on the skin (e.g., the face) for a sufficient time, the composition can preferably be removed by washing or rinsing with water. Preferably, the treated skin is washed or wiped with water, for example, with a moistened or water-wetted pad, a square of gauze, or similar material.

[0064] The compositions of the present invention can be removed by processes consisting solely of rinsing or washing as described above. No neutralization step or separate preparation prior to removal is necessary for the skin-scrubbing compositions of the present invention.

[0065] The application process can be repeated periodically as needed, for example the application can be repeated about every 2 to 7 days, preferably every 2 to 5 days, preferably every 2 to 3 days, with repeated application every two days being preferred.

[0066] Before applying the compositions of the present invention, the skin is preferably cleansed, but this cleansing is optional.

[0067] According to preferred embodiments of the present invention, skin exfoliation methods are provided, comprising the application of compositions of the present invention to the skin in a quantity sufficient to exfoliate the skin. Preferably, the skin exfoliation methods are performed by a consumer and not by a skincare professional using the compositions of the present invention as described above.

[0068] According to preferred embodiments of the present invention, methods for treating skin showing signs of aging, preferably wrinkles and / or fine lines, are proposed, comprising applying compositions of the present invention to the skin showing signs of aging in sufficient quantity to reduce the appearance of wrinkles and / or fine lines. Preferably, these methods are performed by a consumer and not by a skincare professional using the compositions of the present invention as described above.

[0069] According to preferred embodiments of the present invention, methods for smoothing skin texture, preferably skin irregularities resulting from acne, are proposed, comprising applying compositions of the present invention to the skin in sufficient quantity to make the skin texture more uniform (smoother). Preferably, these methods are performed by a consumer and not by a skincare professional using the compositions of the present invention as described above.

[0070] According to preferred embodiments of the present invention, methods for preparing a skin scrub composition are proposed which include: 1. the preparation of a basic aqueous medium by adding at least one alkalizing agent to water, preferably water having a temperature equal to or lower than ambient temperature, in sufficient quantity to produce a basic aqueous medium (pH greater than 7), 2. the addition of one or more AHAs and one or more PHAs one by one to the basic aqueous medium of (1) to gradually reach the approximate final pH of the skin scrub composition, 3. Adding the remaining ingredients of the skin scrub composition (except the BHA(s), monoalcohol(s) and, optionally, the humectant(s)) to the aqueous medium of (2), and 4. the addition of a mixture of one or more BHAs, monoalcohol(s) and, optionally, humectant(s) to the aqueous medium of (3).

[0071] Any alkalizing agent known in the art may be used in accordance with these processes. Suitable alkalizing agents include, but are not limited to, at least one agent alkalizing agent chosen from the group consisting of alkanolamines such as mono-, di- and triethanolamines, alkali metal carbonate salts, sodium hydroxide, potassium hydroxide or calcium hydroxide, and mixtures thereof, sodium hydroxide being the most preferable.

[0072] Any monoalcohol known in the art may be used in accordance with these processes. Suitable C2-C4 monoalcohols include, for example, ethanol, propanol, butanol, isopropanol, and isobutanol. Ethanol is particularly preferred.

[0073] Any humectant known in the art may be used in accordance with these processes. Preferably, at least one humectant comprises at least one hydroxyl group or is a derivative of a compound comprising at least one hydroxyl group. Suitable humectants of this type are known in the art and include, but are not limited to, propylene glycol, butylene glycol, hexylene glycol, glycerin (sometimes called glycerol or glycerin), and glucose ethers. Preferably, at least one humectant is selected from glycerin, propylene glycol, butylene glycol, and mixtures thereof.

[0074] Preferably, in (4), the BHA(s) such as salicylic acid are solubilized in the monoalcohol and, optionally, the humectant before addition to the aqueous medium of (3).

[0075] Unless otherwise stated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in this specification and the claims shall be understood as modified in all cases by the term "approximately". Consequently, unless otherwise stated, the numerical parameters presented in the following specification and the attached claims are approximations that may vary depending on the desired properties that one seeks to obtain through the present invention.

[0076] Although the numerical ranges and parameters illustrating the broad scope of the invention are approximations, the numerical values ​​presented in the specific examples are reported as accurately as possible. However, every numerical value inherently contains some errors necessarily resulting from the standard deviation found in their respective measurements. The following examples are intended to illustrate the invention without thereby limiting its scope. Percentages are given on a weight basis. EXAMPLES

[0077] Example 1 - Preparation of the sample composition

[0078] A sample composition shown in the table below can be prepared as follows:

[0079] [Tables 1] INCI (US / EU) Quantity (% by weight of composition) WATER / AQUA 10 to 50% SODIUM HYDROXIDE 1 to 10% CHELATING AGENT 0.01 to 0.1% GLUCONOLACTONE 1 to 10% MANDELIC ACID 0.5 to 25% LACTIC ACID 2.5 to 20% GLYCOLIC ACID 2.5% to 20% COLOR 0 to 5% GELDING AGENT 0 to 5% ALCOHOL DENAT. 5 to 30% SALICYLIC ACID > 1% to 3% OTHER INGREDIENTS SUCH AS A HUMECTANT, COOLING AGENT, FRAGRANCE, QS

[0080] Introduce sodium hydroxide (NaOH) into water in a cold tank to produce a basic medium.

[0081] AHA and PHA are added one by one into the basic medium to gradually reach the approximate final pH of the formula.

[0082] The remaining ingredients, with the exception of salicylic acid, ethanol and (if applicable) the hydroxy-containing humectant, are added after the addition of AHA and PHA.

[0083] Salicylic acid is solubilized in a phase of denatured alcohol (e.g., ethanol) and (if applicable) of hydroxy-containing humectant (e.g., glycerol), and then added to the rest of the formula.

[0084] This procedure can allow this composition to be prepared without crystallized salicylic acid, and the composition can be stable for up to 2 months (no recrystallization after 2 months at 4 °C).

[0085] Example 2 - Inventive and Comparative Compositions

[0086] The compositions below were prepared according to the description in Example 1:

[0087] [Tables2] Inventive Ingredient A Comparative B Comparative C WATER QS QS QS LACTIC ACID (AHA) 10.00 10.00 10.00 GLYCOLIC ACID (A HA) 7.00 7.00 7.00 MANDELIC ACID (AHA) 1.00 1.00 1.00 GLUCONOLACTONE (PHA) 5.00 5.00 5.00 SALICYLIC ACID (B HA) 2.00 1.00 0.50 GLYCERIN (GLYCOLS) 8.00 8.00 8.00 ALCOHOL DENAT. 5.00 5.00 5.00 Cross-linked polyacrylate-6 polymer (gelling agent) 0.90 0.90 0.90 Sodium hydroxide 4.00 4.00 4.00 Other (active ingredients, fragrance, chelating agent) 0.40 0.40 0.40

[0088] Example 3 - Salicylic acid solubility test

[0089] At the end of the preparation of the compositions of Example 2, the microscopic appearance of the compositions was examined. It could be seen that Inventive Example A (2% salicylic acid) did not contain any visible crystals. However, the comparative examples containing 1% or less of salicylic acid (Comparative Example B (1% salicylic acid) and Comparative Example C (0.5% salicylic acid)) contained visible crystals, with Comparative Example C containing more crystals than Comparative Example B. These results were surprising and unexpected, given that greater crystal formation occurred in compositions containing less salicylic acid. It was determined that more than 1% salicylic acid must be present to obtain acceptable solubility of salicylic acid.

Claims

Demands

1. Skin scrub composition comprising: (a) about 50% by weight or less of water, (b) about 5% to about 30% by weight of monoalcohol(s), wherein the amount of water present in the composition is greater than the amount of monoalcohol(s) present in the composition, (c) about 10% to about 50% by weight of alpha-hydroxy acid(s), (d) more than 1% to about 3% by weight of salicylic acid, and (e) about 1% to about 10% by weight of polyhydroxy acid(s), all weights being relative to the total weight of the composition.

2. Composition according to claim 1, wherein salicylic acid is present in an amount of more than 1% to about 2% by weight relative to the total weight of the composition, preferably about 1.5% to about 2% by weight relative to the total weight of the composition.

3. Composition according to claim 1, wherein a monoalcohol present in the composition is ethanol.

4. Composition according to claim 1, wherein an alpha-hydroxy acid present in the composition is mandelic acid, preferably in an amount from about 1% to about 10% by weight relative to the total weight of the composition, preferably from about 1% to about 5% by weight relative to the total weight of the composition.

5. Composition according to claim 4, wherein two additional alpha-hydroxy acids present in the composition are lactic acid and glycolic acid.

6. Composition according to claim 1, wherein a polyhydroxy acid present in the composition is gluconolactone, preferably in an amount from about 1% to about 10% by weight relative to the total weight of the composition, preferably from about 5% to about 10% by weight relative to the total weight of the composition.

7. Composition according to claim 1, further comprising at least one humectant, preferably in an amount greater than 5% by weight relative to the total weight of the composition.

8. Composition according to claim 1, wherein the pH of the composition is 4 or less.

9. Composition according to claim 1, comprising: (a) about 50% by weight or less of water, (b) about 5% to about 30% by weight of monoalcohol(s), wherein the amount of water present in the composition is greater than the amount of monoalcohol(s) present in the composition, (c) about 15% to about 20% by weight of alpha-hydroxy acid(s), (d) about 2% by weight of salicylic acid, and (e) about 5% to about 10% by weight of polyhydroxy acid(s).

10. A skin exfoliation method comprising applying the skin exfoliation composition of claim 1 to the skin in sufficient quantity to exfoliate the skin, and rinsing the skin composition with water after exfoliation.