SKIN SCRUB COMPOSITIONS

Abstract

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

Description

Title of the invention: SKIN SCRUB COMPOSITIONS FIELD OF THE INVENTION

[0001] The present invention relates to compositions comprising water, monoalcohol, alpha-hydroxy acids, beta-hydroxy acid and polyhydroxy acid, as well as methods of using and making such compositions. The compositions have one or more beneficial attributes, including, for example, containing solubilized beta-hydroxy acid, being well tolerated during use, performing exfoliation at various levels of the skin, not requiring neutralization after application to the skin and / or being suitable for use by a consumer at home. DISCUSSION OF THE CONTEXT

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

[0003] Chemical peels can be classified into superficial, medium and deep chemical peels, depending on the depth of chemical damage to the skin that occurs. Superficial chemical peels are those that remove or effect accelerated replacement or renewal of the epidermis. Medium depth peels penetrate into the papillary dermis. Deep peels penetrate into the reticular dermis. WO 97 / 28786 reports that chemical peeling 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 (about 14%) of resorcinol, salicylic acid and lactic acid (85%).

[0004] Generally, it is possible to solubilize salicylic acid in certain ingredients such as certain surfactants and oils. However, the presence of such compounds in a skin scrub composition may have a negative impact on 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 solubilized).

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

[0007] Potentially relevant publications include: • US 2022 / 0362121 relates to a personal care formulation 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 exfoliating compositions containing salicylic acid derivatives.

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

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

[0010] The present invention relates to skin exfoliating 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 monohydric alcohol, preferably ethanol, wherein the amount of water present in the composition is greater than the amount of monohydric alcohol present in the composition, (c) 10% to 50% by weight of 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 beta-hydroxy acid, preferably salicylic acid, and (e) 1% to 10% by weight of 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 greater than about 5% by weight relative to the total weight of the composition. Also preferably, the pH of the composition is less than 4.

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

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

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

[0015] It should be understood that both the foregoing general description and the following detailed description 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 appended thereto, it is to be understood that the terms used have their ordinary and customary meanings in the art, unless otherwise specified.

[0017] “Approximately” as used herein means within 10% of the number indicated (e.g., “ “about 10%” means 9% to 11% and “about 2%” means 1.8% to 2.2%.

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

[0019] As used herein, all proposed ranges are intended to include each specific range within the given ranges, and all combinations of sub-ranges therein. Thus, a range of 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 substituent. Non-limiting examples of substituents include atoms, such as oxygen atoms 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 be further substituted.

[0021] “Physiologically acceptable” means compatible with the skin and having a pleasant and acceptable color, odor, and feel, and which does not cause unacceptable discomfort that would discourage a consumer from using the composition. Acceptable pH levels for the compositions of the present invention are acidic, i.e., 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] “Naturally occurring compound” means any compound derived from a natural compound which has undergone one or more chemical modifications, for example by organic synthesis reaction, without the properties of the natural compound having been modified.

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

[0025] “Room temperature” means 25°C.

[0026] “Atmospheric pressure” means 760 mmHg, that is, 105 pascals.

[0027] The compositions and methods of the present invention may comprise, consist of, or consist essentially of the essential elements and limitations of the invention described herein, as well as any additional or optional ingredients, components, or limitations described herein or otherwise useful. For example, the solvent system may "consist essentially of" water and a C2-C4 monohydric alcohol, or "consist essentially of water, a C2-C4 monohydric alcohol, 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 the compositions, components and methods which “consist essentially of” the identified ingredients or actions is “beta-hydroxy acid (BHA) solubility”.

[0029] “Exempt” or “substantially free” or “devoid of” as used herein means that although it is preferable that no amount of the specific component is present in the composition, it is possible for there to be very small amounts thereof in the compositions of the invention provided that these amounts do not materially affect at least one, preferably most, of the beneficial properties of the conditioning compositions of the invention. Thus, for example, "free of botanical extracts" means that an effective amount (i.e., greater than trace amounts) of botanical extracts is omitted from the composition (i.e., about 0% by weight), "substantially free of botanical extracts" means that botanical extracts are present in amounts not greater than 0.1% by weight, and "free of botanical extracts" means that botanical extracts are present in amounts not greater than 0.25% by weight, based on the total weight of the composition.“Botanical extract” includes witch hazel, and compositions may also be “free,” “substantially free,” 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 (compositions of the invention that are "free of oils and / or waxes", "substantially free of oils and / or waxes" and "free of oils and / or waxes", and / or "free of surfactants", "substantially free of surfactants" and "free of surfactants" have meanings consistent with the discussion within the preceding paragraph), even if not specifically discussed for each identified ingredient. Discussed examples of the use of such language as those in this and the preceding paragraph are intended to be exemplary embodiments of the present invention, 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 be limited to the materials described and referenced by a certain trade name. Equivalent materials (e.g., those obtained from a different source under a different catalog name or (reference) number) to those referenced by a trade name may be substituted and used in the methods described and claimed herein.

[0032] All percentages and ratios are, unless otherwise indicated, calculated by weight. All percentages are, unless otherwise indicated, calculated based on the total weight of a composition. All levels of component or composition refer to the active level of that component or composition, and are exclusive of impurities, e.g., 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 provided. 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. More preferred compositions contain glycolic acid and lactic acid in addition to mandelic acid.

[0035] Preferably, the 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 based on 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 based on 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 based on 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 based on 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 (BHAs)

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

[0040] Preferably, the 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 greater than (or above) 1% to about 3%, and preferably from greater than 1% to about 2% by weight based on 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 most preferably about 11:1 to about 7:1, including all intermediate ranges and sub-ranges.

[0042] According to preferred embodiments, where salicylic acid and mandelic acid are present in the compositions of the present invention, the salicylic acid and mandelic acid are present in the compositions of the present invention in a weight ratio of about 1:10 to about 4:1, preferably about 1:5 to about 3:1, and most preferably about 1:1 to about 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 provided. 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, the 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 based on 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 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 about 15:1 at about 1:1, preferably from about 10:1 to about 2:1, and preferably from about 6:1 to about 2.5:1, including all intermediate ranges and sub-ranges.

[0047] According to preferred embodiments, where 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 about 1:10 to about 10:1, preferably about 1:5 to about 5:1, and most preferably about 5:1 to about 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 / monoalcohol

[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 based on the total weight of the composition; and (ii) at least one C2-C4 monohydric alcohol are provided.

[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% by weight of water, all weights being based on the total weight of the composition, including all intermediate ranges and sub-ranges, such as, for example, from 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 monohydric alcohol(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 phase solvent system of the compositions of the present invention consists essentially of, or consists of, water and one or more C2-C4 monohydric alcohols. Preferably, the aqueous phase solvent system is "free", "lacking" or "substantially free" of solvents other than water and the one or more C2-C4 monohydric alcohols. Humectant

[0054] According to preferred embodiments, the compositions of the present invention optionally further 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 referred to as glycerol or glycerin) and glucose ethers. Preferably, the at least one humectant is selected from glycerin, propylene glycol, butylene glycol and mixtures thereof.

[0055] Optionally, the 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 based on 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, in some embodiments, the compositions of the present invention are "free", "substantially free" or "devoid" of humectant. Additional optional ingredients

[0057] The composition of the invention may also comprise any additive commonly used in the field under consideration. 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 may be found in US Patent Application Publication No. 2004 / 0170586. Other examples of suitable additional components may be found in the other references. Still other examples of these additional ingredients may 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 discussed in this paragraph such as oils, waxes, surfactants, botanical extracts, etc.

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

[0059] These substances can be selected in various ways by the 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 that it must contain a physiologically acceptable non-toxic medium.

[0061] The skin exfoliating compositions of the present invention may be applied in any manner, for example, by wiping, dispensing, etc. (hereinafter referred to as "application"). For example, application of the compositions of the invention may be done manually, for example, using one or more fingers, using an absorbent cotton pad soaked in the concentrated solution, using a sable hair brush soaked in the solution, gently wiping with an absorbent fibrous material soaked in the solution such as a square 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 at the consumer's home; (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 application of the skin scrub composition of the present invention.

[0062] The applied compound or composition is generally allowed to air dry over a relatively short period of time, preferably 20 minutes or less, and most preferably 15 minutes or less, with about 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 may be removed preferably by washing or rinsing with water. Preferably, the treated skin is washed or wiped with water, for example, with a water-moistened or moistened pad, square gauze, or the like.

[0064] The compositions of the present invention may be removed by methods consisting only of rinsing or washing as described above. No separate neutralization step or composition prior to removal is necessary for the skin scrub compositions of the present invention.

[0065] The application process may be repeated periodically as needed, for example the application may be repeated approximately every 2 to 7 days, preferably every 2 to 5 days, preferably every 2 to 3 days, with repeated application every other day being preferred.

[0066] Prior to application of the compositions of the present invention, the skin is preferably cleansed, but such cleansing is optional.

[0067] According to preferred embodiments of the present invention, methods of exfoliating skin comprising applying compositions of the present invention to the skin in an amount sufficient to exfoliate the skin are provided. Preferably, the methods of exfoliating skin are performed by a consumer and not by a skin care professional using the compositions of the present invention as discussed above.

[0068] According to preferred embodiments of the present invention, methods of treating skin that contains signs of aging, preferably wrinkles and / or fine lines, comprising applying compositions of the present invention to the skin that contains the signs of aging in an amount sufficient to reduce the appearance of the wrinkles and / or fine lines, are provided. Preferably, these methods are performed by a consumer and not by a skin care professional using the compositions of the present invention as discussed above.

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

[0070] According to preferred embodiments of the present invention, methods of making a skin scrub composition are provided which comprise: 1. preparing a basic aqueous medium by adding at least one basifying agent to water, preferably water having a temperature equal to or lower than room temperature, in an amount sufficient to produce a basic aqueous medium (pH greater than 7), 2. adding 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), the monoalcohol(s) and, optionally, the humectant(s)) to the aqueous medium of (2), and 4. adding a mixture of one or more BHAs, monoalcohol(s) and, optionally, humectant(s) to the aqueous medium of (3).

[0071] Any basifying agent known in the art may be used in accordance with these methods. Suitable basifying agents include, but are not limited to, at least one agent basifier selected 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 most preferable.

[0072] Any monohydric alcohol known in the art may be used in accordance with these methods. Suitable C2-C4 monohydric alcohols 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 methods. Preferably, 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 referred to as 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 indicated, all numbers expressing amounts of ingredients, reaction conditions, and so forth used in this specification and the claims are to be understood as being modified in all instances by the term "about." Accordingly, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximations which may vary depending on the desired properties sought to be achieved by the present invention.

[0076] Although the numerical ranges and parameters exhibiting the broad scope of the invention are approximations, the numerical values presented in the specific examples are reported as accurately as possible. However, any numerical value inherently contains certain errors necessarily resulting from the standard deviation found in their respective measurements. The following examples are intended to illustrate the invention without limiting its scope accordingly. 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 the 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% GELLING AGENT 0 to 5% ALCOHOL DENAT. 5 to 30% SALICYLIC ACID > 1% to 3% OTHER INGREDIENTS SUCH AS A HUMECTANT, A COOLING AGENT, A PERFUME, QS

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

[0081] The 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, except salicylic acid, ethanol and (if applicable) hydroxy-containing humectant, are added after the addition of AHA and PHA.

[0083] The salicylic acid is solubilized in a phase of denatured alcohol (e.g., ethanol) and (optionally) hydroxy-containing humectant (e.g., glycerol), and then added to the remainder of the formula.

[0084] This procedure can make it possible to prepare this composition 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] Ingredient Inventive 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 POLYACRYLATE-6 CROSSLINKED POLYMER (GELLING AGENT) 0.90 0.90 0.90 SODIUM HYDROXIDE 4.00 4.00 4.00 OTHERS (active ingredients, perfume, CHELATING AGENT) 0.40 0.40 0.40

[0088] Example 3 - Salicylic Acid Solubility Test

[0089] Upon completion 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 visible crystals. However, the comparative examples containing 1% or less salicylic acid (Comparative Example B (1% salicylic acid) and Comparative Example C (0.5% salicylic acid)) did contain visible crystals, with Comparative Example C containing more crystals than Comparative Example B. These results were surprising and were not expected since greater crystal formation occurred in compositions containing less salicylic acid. It was determined that more than 1% salicylic acid needed to be present to achieve acceptable solubility of salicylic acid.

Claims

Claims

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

2. The composition of claim 1, wherein the salicylic acid is present in an amount of more than 1% to about 2% by weight based on the total weight of the composition, preferably from about 1.5% to about 2% by weight based on the total weight of the composition.

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

4. The composition of claim 1, wherein an alpha-hydroxy acid present in the composition is mandelic acid, preferably in an amount ranging 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. The composition of claim 4, wherein two additional alpha-hydroxy acids present in the composition are lactic acid and glycolic acid.

6. The composition of claim 1, wherein a polyhydroxy acid present in the composition is gluconolactone, preferably in an amount ranging 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. The composition of claim 1, wherein the pH of the composition is 4 or less.

9. The composition of 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 method of exfoliating skin comprising applying the skin exfoliating composition of claim 1 to the skin in an amount sufficient to exfoliate the skin, and rinsing the composition from the skin with water after exfoliating.