Self-tanning compositions and methods containing alkyl sulfonates

Abstract

A topical skin care composition comprising (A) a reducing sugar, (B) an optionally substituted C 8‑12 An alkyl sulfonate and (C) a carrier. The composition further comprises an aromatic sulfonate. A method for enhancing the appearance of skin color (e.g., hue angle, brightness, saturation) is also described, the method comprising applying a topical skin care composition to the skin. When applied to the skin, the topical skin care composition can provide a deep, vivid, long-lasting artificial tan with customizable hue retention or adjustability.

Description

Technical Field

[0001] The present invention relates to topical skin care compositions, in particular to topical skin care compositions comprising (A) reducing sugars, (B) alkyl sulfonates and (C) carriers, and methods of self-tanning using the topical skin care compositions. Background Art

[0002] The “background technology” description herein is used to generally represent the context of the present disclosure. To the extent of this “background technology” description, the work of the presently named inventors, as well as aspects of the description that may not constitute prior art at the time of filing, are neither explicitly nor implicitly admitted to be prior art against the present invention.

[0003] Consumers worldwide enjoy spending time in the sun for a variety of reasons, including outdoor recreation, sports, and sun tanning (darkening of skin color). Unfortunately, exposure to ultraviolet (UV) radiation is known to have the potential to cause skin cancer. In addition, partial exposure to UV radiation can result in uneven skin tone throughout the body. Therefore, there is a health and aesthetic incentive to seek alternative methods of achieving a natural-looking, even skin tone while avoiding the dangers of exposure to the sun.

[0004] Despite the known risks, sunbathing remains the most common method of darkening the skin in the United States and the European Union. Sunless tanning agents and luminous moisturizers are also commonly used, but many consumers are dissatisfied with these products because the color is often perceived as unnatural, not dark enough, or fading quickly. For example, many conventional self-tanning products contain dihydroxyacetone (DHA) tanning agents that produce an undesirable orange tint. In addition to skin darkening, some consumers prefer to retain their skin's original tone, while others want to shift the tone to a more aesthetically pleasing bronze / reddish hue.

[0005] There have been several reports of skin tanning formulations that use azole compounds, pigments (e.g., carmine), cross-linked cationic copolymers, and vanillin polymers to enhance skin color (U.S. Pat. Nos. 5,705,145, 6,214,322, 7,780,954, and 7,935,331, each of which is incorporated herein by reference). However, there remains a need for improved formulations that can effectively darken skin color while maintaining the original skin tone. Summary of the invention

[0006] In view of the foregoing, there exists a need for a long-lasting topical skin care composition that produces deeper, more vibrant color without altering the skin's original tone.

[0007] It is therefore an object of the present invention to provide novel topical skin care compositions which meet these criteria.

[0008] It is another object of the present invention to provide novel methods for regulating the appearance of a subject's skin tone by topically applying a topical skin care composition to the subject's skin.

[0009] As will be seen in the detailed description below, these and other objects are achieved by the inventors' discovery that the combination of a reducing sugar, an alkyl sulfonate, and a carrier unexpectedly produces a topical skin care composition that promotes a long-lasting, vivid, intense (i.e., darker), and natural tan by increasing saturation and darkness after topical application while maintaining the original hue of the skin color. Furthermore, when an aromatic sulfonate is included, the topical skin care composition provides a customized tan by changing the hue in addition to darkening and saturating the skin color.

[0010] Therefore, the present invention provides:

[0011] (1) A topical skin care composition comprising:

[0012] (A) about 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition,

[0013] (B) optionally substituted C 8-12 Alkyl sulfonates, and

[0014] (C) a carrier,

[0015] wherein the optionally substituted C 8-12 The weight ratio of the alkyl sulfonate (B) to the reducing sugar (A) ((B):(A)) is 1:20 to 20:1.

[0016] (2) The topical skin care composition of (1), wherein the optionally substituted C 8-12 The alkyl sulfonate (B) is an unsubstituted alkyl sulfonate.

[0017] (3) The topical skin care composition of (1) or (2), wherein the optionally substituted C 8-12 The alkylsulfonate (B) is an alkali metal salt of an alkylsulfonic acid.

[0018] (4) The topical skin care composition of any one of (1) to (3), wherein the optionally substituted C 8-12 The alkyl sulfonate (B) is sodium 1-octyl sulfonate, sodium 1-decyl sulfonate or both.

[0019] (5) The topical skin care composition of any one of (1) to (4), wherein the optionally substituted C 8-12 The alkyl sulfonate (B) is sodium 1-octyl sulfonate.

[0020] (6) The topical skin care composition of any one of (1) to (5), wherein the optionally substituted C 8-12The weight ratio of the alkyl sulfonate (B) to the reducing sugar (A) ((B):(A)) is 1:20 to 20:1.

[0021] (7) The topical skin care composition of any one of (1) to (6), wherein the carrier (C) comprises a aromatic alcohol.

[0022] (8) The topical skin care composition of any one of (1) to (7), wherein the carrier (C) comprises benzyl alcohol.

[0023] (9) The topical skin care composition according to any one of (1) to (8), further comprising (D) an organic solvent.

[0024] (10) The topical skin care composition of (9), wherein the organic solvent (D) is at least one selected from 1,3-propylene glycol, 1,2-propylene glycol and 1,3-butylene glycol.

[0025] (11) The topical skin care composition of any one of (1) to (10), which is substantially free of a cationic copolymer.

[0026] (12) The topical skin care composition of any one of (1) to (11), further comprising (E) an aromatic sulfonate, wherein the aromatic sulfonate (E) has a molecular weight less than The topological polar surface area (tPSA) of

[0027] (13) The topical skin care composition of (12), wherein the aromatic sulfonate (E) is an optionally substituted phenyl sulfonate, an optionally substituted naphthyl sulfonate, or both.

[0028] (14) The topical skin care composition of (12) or (13), wherein the aromatic sulfonate (E) is at least one selected from the group consisting of sodium 2-naphthyl sulfonate, sodium p-toluene sulfonate and sodium cumene sulfonate.

[0029] (15) The topical skin care composition of any one of (12) to (14), wherein the weight ratio of the alkyl sulfonate (B) to the aromatic sulfonate (E) ((B):(E)) is 1:100 to 100:1.

[0030] (16) A method for darkening and maintaining the skin tone of a subject, the method comprising:

[0031] topically applying the topical skin care composition of any one of (1) to (15) to the skin of a subject,

[0032] Therein, the topical application reduces the lightness L* of the color by at least 10% compared to before the topical application, and the change in the hue angle h° of the color is less than 2°.

[0033] (17) The method of (16), wherein the topical skin care composition is topically applied to the subject 1 to 3 times per day for 1 to 7 consecutive days.

[0034] (18) A method for darkening the skin color of a subject, the method comprising:

[0035] topically applying the topical skin care composition of any one of (1) to (15) to the skin of a subject,

[0036] Therein, the topical application reduces the lightness L* of the color by at least 10% compared to before the topical application.

[0037] (19) A method for adjusting the color saturation of a subject's skin, the method comprising:

[0038] topically applying the topical skin care composition of any one of (1) to (15) to the skin of a subject,

[0039] Wherein the topical application increases the saturation C* of the color by at least 10% compared to before the topical application.

[0040] (20) A range of topical skin care products for retail sale, the range comprising:

[0041] (a) a first topical skin care composition comprising:

[0042] (A) about 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition,

[0043] (B) optionally substituted C 8-12 Alkyl sulfonates, and

[0044] (C) a carrier,

[0045] wherein the optionally substituted C 8-12 The weight ratio of the alkyl sulfonate (B) to the reducing sugar (A) ((B):(A)) is 1:20 to 20:1; and

[0046] (b) a second topical skin care composition comprising:

[0047] (A) about 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition,

[0048] (B) optionally substituted C 8-12 Alkyl sulfonates, and

[0049] (C) a carrier,

[0050] wherein the optionally substituted C 8-12 The weight ratio of alkyl sulfonate (B) to reducing sugar (A) ((B):(A)) is 1:20 to 20:1,

[0051] wherein the content of reducing sugar (A) present in the first topical skin care composition (a) is less than the content of reducing sugar (A) present in the second topical skin care composition (b), and wherein the content is each content relative to the total weight of the first and second topical skin care compositions.

[0052] (21) The series of (20), wherein the first topical skin care composition (a) and the second topical skin care composition (b) are packaged separately.

[0053] (22) The series of (20) or (21), wherein the content of reducing sugar (A) relative to the total weight of the first topical skin care composition (a) is less than 5%, and the content of reducing sugar (A) relative to the total weight of the second topical skin care composition (b) is greater than 5%.

[0054] (23) A topical skin care composition comprising:

[0055] (A) about 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition,

[0056] (B) optionally substituted C 8-12 Alkyl sulfonates, and

[0057] (C) a carrier,

[0058] wherein the reducing sugar (A) is dihydroxyacetone, erythrulose or both,

[0059] wherein the optionally substituted C 8-12 Alkyl sulfonate (B) is an unsubstituted alkyl sulfonate,

[0060] wherein the carrier (C) comprises an aromatic alcohol, and

[0061] wherein the optionally substituted C 8-12 The weight ratio of the alkyl sulfonate (B) to the reducing sugar (A) ((B):(A)) is 1:20 to 20:1.

[0062] (24) The topical skin care composition of (23), further comprising (D) an organic solvent.

[0063] (25) The topical skin care composition of (23), which is substantially free of cationic copolymers.

[0064] (26) The topical skin care composition of (23), further comprising (E) an aromatic sulfonate, wherein the aromatic sulfonate (E) has a molecular weight less than The topological polar surface area (tPSA) of

[0065] (27) A topical skin care composition comprising:

[0066] (A) about 0.1-10 wt.% of reducing sugar relative to the total weight of the topical skin care composition,

[0067] (B) about 0.1-10 wt.% of optionally substituted C based on the total weight of the topical skin care composition 8-12 Alkyl sulfonates, and

[0068] (C) about 0.1-5 wt.% of a carrier relative to the total weight of the topical skin care composition,

[0069] wherein the reducing sugar (A) is dihydroxyacetone, erythrulose or both,

[0070] wherein the optionally substituted C 8-12 Alkyl sulfonate (B) is an unsubstituted alkyl sulfonate,

[0071] wherein the carrier (C) comprises an aromatic alcohol, and

[0072] wherein the optionally substituted C 8-12 The weight ratio of the alkyl sulfonate (B) to the reducing sugar (A) ((B):(A)) is 1:5 to 5:1.

[0073] (28) The topical skin care composition of (27), further comprising (D) an organic solvent.

[0074] (29) The topical skin care composition of (27), which is substantially free of cationic copolymers.

[0075] (30) The topical skin care composition of (27), further comprising (E) an aromatic sulfonate, wherein the aromatic sulfonate (E) has a molecular weight less than The topological polar surface area (tPSA) of

[0076] The foregoing paragraphs are provided as a general introduction and are not intended to limit the scope of the appended claims.The described embodiments, together with further advantages, will be best understood by reference to the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] This patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawing(s) will be provided by the Office upon request and payment of the necessary fee.

[0078] A more complete understanding of the present disclosure will be obtained, and its many attendant advantages will also be better appreciated when the following detailed description is considered in conjunction with the accompanying drawings, in which:

[0079] Figure 1are bar graphs showing changes in skin darkness 6 hours and 24 hours after application of a control composition containing only DHA (A), and a topical skin care composition containing DHA and sodium 1-decyl sulfonate (SDS) (B), respectively.

[0080] Figure 2 is a color calibration photograph showing human skin treated with a control composition containing only DHA ("Control") (upper circle) and a topical skin care composition containing DHA and SDS ("SDS") (lower circle), wherein color calibration was performed using the CASMATCH method (Bear Medic Co.).

[0081] Figure 3 Bar graphs showing changes in skin darkness after 3 days (once a day for 3 consecutive days) and 7 days (once a day for 7 consecutive days) of application of a control composition containing only DHA (A) and a topical skin care composition containing DHA and sodium 1-octane sulfonate (SOS) (B), as well as 3-day regression after 7 days of application.

[0082] Figure 4 Bar graphs showing the change in skin tone angle after 3 days (once a day for 3 consecutive days) and 7 days (once a day for 7 consecutive days) of application of a control composition containing only DHA (A) and a topical skin care composition containing DHA and SOS (B), respectively, and the 3-day regression after 7 days of application.

[0083] Figure 5 : are bar graphs summarizing the changes in skin darkness 4 hours, 24 hours, and 48 hours after applying a control composition containing only DHA (A), a topical skin care composition containing DHA and SOS (B), a topical skin care composition containing DHA and sodium 1-decyl sulfonate (SDS) (C), a topical skin care composition containing DHA and sodium dodecylbenzene sulfonate (SDBS) (D), and a topical skin care composition containing DHA and sodium lauryl sulfoacetate (SLSA) (E), respectively.

[0084] Fig. 6A 2 are bar graphs summarizing the changes in skin darkness after application of a control composition containing DHA alone (DHA), a topical skin care composition containing DHA and SOS (+SOS), a control composition containing DHA and sodium 2-naphthyl sulfonate (NSA) (+NSA), and a topical skin care composition containing DHA, SOS and NSA (+NSA / SOS), respectively.

[0085] Figure 6B is a photograph showing human skin treated with a topical skin care composition containing DHA and SOS.

[0086] Figure 6C is a photograph showing human skin treated with a control composition containing DHA and NSA.

[0087] Fig.6D are photographs showing human skin treated with a topical skin care composition containing DHA, SOS and NSA.

[0088] Figure 7 is a bar graph showing the relative α-helix / β-sheet index ratio of keratin when exposed to aqueous solutions containing SOS, SDS and sodium dodecyl sulfate (SLS), respectively.

[0089] Figure 8 It is part of the hue diagram depicted by the CIE L*C*h° and CIE L*a*b* color space models.

[0090] Fig.9A is a graph summarizing the different darkness (L*) induced by DHA in the presence of SOS, SDS and sodium dodecyl sulfate (SLS), respectively.

[0091] Fig. 9B Depicts the structural change of keratin from α-helix to β-sheet.

[0092] Fig. 10A is a photo showing a dry stratum corneum.

[0093] Fig. 10B is a photograph showing the stratum corneum exposed to deionized water.

[0094] Fig. 10C is a photograph showing the stratum corneum exposed to a control composition having only DHA.

[0095] Fig. 10D is a photograph showing the stratum corneum exposed to a topical skin care composition containing DHA and SOS.

[0096] Fig.10E is a photograph showing the stratum corneum exposed to a topical skin care composition containing DHA, SOS and 5 wt.% 1,3-propylene glycol (PD).

[0097] Fig.10F is a photograph showing the stratum corneum exposed to a topical skin care composition containing DHA, SOS and 10 wt.% PD.

[0098] Figure 10Gare bar graphs summarizing the different darkness (L*) induced by a control composition containing DHA alone (DHA), a topical skin care composition containing DHA and SOS (DHA / SOS), a topical skin care composition containing DHA, SOS and 5 wt.% PD (+5% PD), and a topical skin care composition containing DHA, SOS and 10 wt.% PD (+10% PD), respectively. DETAILED DESCRIPTION

[0099] From the following description, it is understood that other embodiments may be utilized and structural and operational changes may be made without departing from the scope of the embodiments disclosed herein.

[0100] definition

[0101] As used herein, the words "a", "an" and the like carry the meaning of "one or more".

[0102] In the description of the present disclosure, when a numerical limit or range is stated, the endpoints are included. In addition, all values ​​and sub-ranges within the numerical limit or range are specifically included as if explicitly written.

[0103] When referring to a topical skin care composition, unless otherwise indicated, the phrase "substantially free" describes that the amount of the particular component present in the topical skin care composition is less than about 1 wt.%, preferably less than about 0.5 wt.%, more preferably less than about 0.1 wt.%, even more preferably less than about 0.05 wt.%, and still more preferably 0 wt.%, relative to the total weight of the topical skin care composition.

[0104] As used herein, the word "about" may be used when describing a size and / or position to indicate that the value and / or position described is within a reasonably expected range of values ​​and / or positions. For example, a numerical value may have a value of + / -0.1% of a specified value (or value range), a value of + / -1% of a specified value (or value range), a value of + / -2% of a specified value (or value range), a value of + / -5% of a specified value (or value range), or a value of + / -10% of a specified value (or value range).

[0105] As used herein, the term "optional" or "optionally" means that the subsequently described event may or may not occur, or the subsequently described component may or may not be present (eg, 0 wt.%).

[0106] As used herein, the term "substituted" means that at least one hydrogen atom is replaced with a non-hydrogen group as long as normal valences are maintained and the substitution results in a stable compound.

[0107] As used herein, unless otherwise indicated, the term "alkyl" refers to a straight chain, branched or cyclic aliphatic moiety having at least 1, preferably at least 2, preferably at least 3, preferably at least 4 carbon atoms and up to 22, preferably up to 20, preferably up to 18, preferably up to 12, preferably up to 8 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, neopentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl (lauryl), n-tetradecyl (myristyl), n-pentadecyl, n-hexadecyl (cetyl), n-octadecyl (stearyl), n-eicosyl, 3-methylpentyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, and the like, including Guerbet-type alkyl groups (e.g., 2-methylpentyl, 2-ethylhexyl, 2-propylheptyl, 2-butyloctyl, 2-pentylnonyl, 2-hexyldecyl, 2-heptylundecyl, 2-octyldodecyl, 2-nonyltridecyl, 2-decyltetradecyl, and 2-undecylpentadecyl). Cycloalkyl is a cyclized alkyl group. Exemplary cycloalkyl groups include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, and adamantyl.

[0108] As used herein, the term "aryl" refers to aromatic groups containing only carbon in the aromatic ring, for example, phenyl, biphenyl, naphthyl, anthracenyl, and the like.

[0109] As used herein, the term "arylalkyl" refers to a straight chain, branched or cyclic alkyl moiety (as defined above) substituted by an aryl group (as defined above), which aryl group itself may be optionally substituted by an alkyl group, for example, including but not limited to benzyl, phenethyl, 3-phenylpropyl, 2-phenylpropyl, 1-phenylpropyl, 4-phenylbutyl, 3-phenylbutyl, 2-phenylbutyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 2,4-dimethylbenzyl, 2-(4-ethylphenyl)ethyl, 3-(3-propylphenyl)propyl, and the like.

[0110] As used herein, the term "alkoxy" refers to a straight or branched chain alkyl group attached to an oxygen atom. Exemplary alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentyloxy, isopentyloxy, hexyloxy, heptyloxy, octyloxy, nonyloxy, and decyloxy.

[0111] The term "alkoxycarbonyl" as used in this disclosure refers to an alkoxy group bound to a carbonyl group (ie, >C=0).

[0112] As used herein, the term "halogen" refers to fluorine, chlorine, bromine and iodine.

[0113] As used herein, unless otherwise indicated, the term "alkenyl" refers to a straight chain, branched or cyclic aliphatic fragment having 2 to 22 carbon atoms, preferably 3 to 20 carbon atoms, more preferably 4 to 18 carbon atoms, and containing at least one unsaturated site. Examples of alkenyl include, but are not limited to, vinyl, allyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl, oleyl, linoleyl, etc., including cycloalkenyl groups such as cyclopentenyl, cyclohexenyl, cycloheptenyl, etc.

[0114] As used herein, the term "skin" refers to the skin present in humans and other mammals. It should be recognized that skin is present in many different parts of the body, and the application of the topical skin care compositions herein is not limited to the skin present on a particular part of the body. For example, the topical skin care compositions can be applied to any area of ​​skin where a tan is intended, including the face, limbs, feet, neck, trunk, etc. In addition, the topical skin care compositions can be used as a moisturizer on the whole body in a daily skin care routine.

[0115] Various topical skin care composition ingredients are listed throughout this disclosure and are assigned according to their primary or most desired function, benefit, or use. However, categorizing an ingredient under a particular function, benefit, or use does not mean that the ingredient is limited to that function, benefit, or use. For example, listing benzyl alcohol as a carrier does not limit the use of benzyl alcohol to only a carrier, as benzyl alcohol may also impart other beneficial properties, such as acting as a preservative and / or a fragrance.

[0116] Topical skin care compositions

[0117] The present disclosure relates to a sunless tanning topical skin care composition that reduces the lightness of skin appearance, increases the color saturation of skin appearance, and produces a customized skin appearance tone. The topical skin care composition is easy to apply, can be used to deepen skin color, maintain or adjust the original skin tone, and provide a vivid and long-lasting tan.

[0118] Thus, topical skin care compositions include components that enable skin tanning and components that facilitate the delivery of tanning agents and facilitate the application of topical skin care compositions to reduce skin lightness and maintain skin tone. Such compositions typically include the following components: a tanning agent, preferably (A) a reducing sugar; (B) an alkyl sulfonate; (C) a carrier; and optionally (D) an organic solvent; (E) an aromatic sulfonate; (F) water; (G) a thickener; (H) a preservative and (I) an acidulant. In a preferred embodiment, all components coexist with the reducing sugar (i.e., do not react or cause the reducing sugar to react) and are uniformly dispersed or uniformly dissolved throughout the topical skin care composition. Surprisingly, it has been found that the addition of an alkyl sulfonate to a reducing sugar can enhance the self-tanning effect of the composition. For example, the presence of an alkyl sulfonate in a composition containing a reducing sugar maintains the original hue angle (h°) in addition to increasing the depth and saturation (C*) of the treated skin color.

[0119] The topical skin care composition can be in the form of a liquid, solution, emulsion, lotion, cream, gel, paste, spray, foam, or any other form suitable for topical application to the skin. Preferably, the topical skin care composition is in the form of a lotion, cream, gel, spray or foam. More preferably, the topical skin care composition is in the form of a cream or gel that can be applied evenly.

[0120] Tanning reagent

[0121] In order to be effective as self-tanning agents, the topical skin care compositions herein include a "tanning agent," which is any colored molecule capable of tinting the skin upon contact with the skin, or any colorless molecule capable of reacting with and coloring the skin, particularly molecules capable of darkening the skin so as to resemble the darkening effect achieved by exposing the skin to solar radiation (i.e., a natural tan).

[0122] In a preferred embodiment, the tanning agent is (A) a reducing sugar. Certain reducing sugars such as monosaccharides (e.g., dihydroxyacetone) react with naturally occurring amino acids on the surface of the skin and form pigmented melanoidins (Bobin et al., J. Soc. Cosmet. Chem., 35 pages 265-272, 1984; Maillard LC, CR Acad. Sci. 154, 66-68, 1912—each of which is incorporated herein by reference in its entirety) through the Maillard reaction.

[0123] Different amino acids react differently with different reducing sugars, thereby producing various shades from yellow to brown. Any reducing sugar that can react with amino acids present in the skin (e.g., naturally occurring amino acids) to cause the skin to darken can be used as a tanning agent herein. Reducing sugar (A) can be a monosaccharide having 2 to 6 carbon atoms, preferably 3 to 5 carbon atoms, more preferably 3 to 4 carbon atoms, and even more preferably 3 carbon atoms; a ketose having 3 to 6 carbon atoms, preferably 4 to 5 carbon atoms, more preferably 3 to 4 carbon atoms, including mixtures of such aldoses and / or ketoses. Examples of reducing sugars include, but are not limited to, dihydroxyacetone (DHA), erythrulose, glycolaldehyde, glyceraldehyde, mesotartaric aldehyde, glucose, gulose, xylose, fructose, ribose, arabinose, allose, talose, altrose, idose, mannose, galactose, and erythrose. In a preferred embodiment, the reducing sugar (A) is dihydroxyacetone, erythrulose or both. Most preferably, the reducing sugar (A) is dihydroxyacetone. Dihydroxyacetone can be obtained, for example, from EMD Millipore.

[0124] The amount of tanning agent present in the topical skin care composition can vary depending on the desired skin color (e.g., brightness, hue angle, color saturation) and the amount and nature of other components. In some embodiments, the tanning agent is present in an amount of at least about 0.05 wt.%, preferably at least about 0.1 wt.%, preferably at least about 0.5 wt.%, preferably at least about 1 wt.%, more preferably at least about 1.5 wt.%, even more preferably at least about 1.75 wt.%, and even more preferably at least about 2 wt.%, and up to about 10 wt.%, preferably up to about 8 wt.%, preferably up to about 6 wt.%, preferably up to about 4 wt.%, preferably up to about 3.5 wt.%, more preferably up to about 3 wt.%, even more preferably up to about 2.5 wt.%, and even more preferably up to about 2.25 wt.%, based on the total weight of the topical skin care composition.

[0125] In a preferred embodiment, the topical skin care composition is substantially free of tanning agents other than reducing sugars, including substantially free, preferably completely free (i.e., 0 wt.%) of color-providing synthetic dyes and natural pigments. Alternatively, the topical skin care composition may include other tanning agents, such as synthetic dyes and / or natural pigments in the amounts listed above.

[0126] Examples of synthetic dyes that can be incorporated as tanning agents include, but are not limited to, acid dyes (e.g., Yellow 203 (D&C Yellow 10, Color Index (CI) given as CI 47005), Orange 205 (D&C Orange 4, CI 15510), Red 3 (Erythrosin B, CI 45430), Red 94 (Bengal Rose, CI 45440), and Red 227 (D&C Red 33, CI 45440). 17200)); quinone-based dyes (e.g., anthraquinone, 1-N-methylmorpholinopropylamino-4-hydroxyanthraquinone, 1-aminopropylamino-4-methylaminoanthraquinone, 1-aminopropylaminoanthraquinone, 5-β-hydroxyethyl-1,4-diaminoanthraquinone, 2-aminoethylaminoanthraquinone, 1,4-bis(β,γ-dihydroxypropylamino)anthraquinone, lawsone, juglone, alizarin, purpurin, carminic acid, carmine, kermesic acid acid), spinulosin, disperse red 15, solvent violet 13, disperse violet 1, disperse violet 4, disperse blue 1, disperse violet 8, disperse blue 3, disperse red 11, disperse blue 7, basic blue 22, disperse violet 15, basic blue 99); azo dyes (e.g., 1,3-dimethyl-2-[[4-(dimethylamino)phenyl]azo]-1H-imidazole chloride, 1,3-dimethyl-2-[(4-aminophenyl]azo]-1H-imidazole chloride, 1-methyl-4-[(methylphenylhydrazono)methyl]pyridinium methyl sulfate methylsulfate), Disperse Red 17, Basic Red 22, Basic Red 76, Basic Yellow 57, Basic Brown 16, Basic Brown 17, Disperse Black 9); and indoleamine dyes (e.g., 2-β-hydroxyethylamino-5-[bis(β-4'-hydroxyethyl)amino]anilino-1,4-benzoquinone, 2-β-hydroxyethylamino-5-(2'-methoxy-4'-amino)anilino-1,4-benzoquinone, 3-N-(2'-chloro-4'-hydroxy)phenylacetamido-6-methoxy-1,4-benzoquinoneimine, 3-N-(3'-chloro-4'-methylamino)phenylureido-6-methyl-1,4-benzoquinoneimine, 3-[4'-N-(ethylcarbamoylmethyl)amino]phenylureido-6-methyl-1,4-benzoquinoneimine).

[0127] The topical skin care composition may include natural pigments as tanning agents. Non-limiting examples of natural dyes include caramel, beta-carotene, beetroot extract, blue-green algae, cocoa powder, walnut extract, melanin, and curcumin.

[0128] (B) Alkyl sulfonate

[0129] The topical skin care composition of the present disclosure may include an alkyl sulfonate (B). Preferably, the alkyl sulfonate (B) has the formula (I) or a solvate thereof, a tautomer thereof, a stereoisomer thereof, or a mixture thereof,

[0130]

[0131] wherein (i) R1 is an optionally substituted alkyl group or an optionally substituted arylalkyl group, and (ii) X is a cation selected from a hydrogen ion, an ammonium ion, and an alkali metal ion. The term "cation" refers to a positively charged ion, including but not limited to a hydrogen ion, an ammonium ion (i.e., NH4 + ), quaternary ammonium ions (such as tetraethylammonium, tetrabutylammonium), lithium ions, sodium ions, potassium ions and silver ions. Preferably, the alkyl sulfonate (B) is an alkali metal salt of an alkyl sulfonate. In a preferred embodiment, X is an alkali metal ion, such as lithium ions, sodium ions and potassium ions. Most preferably, X is a sodium ion.

[0132] In some embodiments, R1 is optionally substituted C 1-22 Alkyl, preferably optionally substituted C 2-20 Alkyl, preferably optionally replaced C 3-18 Alkyl, preferably optionally substituted C 4-16 Alkyl, preferably optionally substituted C 5-14 Alkyl, preferably optionally substituted C 6-12 Alkyl, preferably optionally substituted C 7-10 Alkyl, preferably optionally substituted C 8-9 Alkyl Group: The carbon atom number described herein refers to the carbon atom number of the R1 alkyl group and does not include the carbon atoms of the optionally present substituents.

[0133] In a preferred embodiment, R1 is an unsubstituted alkyl group, preferably a straight chain alkyl group, preferably a straight chain C 1-18 Alkyl, preferably straight chain C 2-16 Alkyl, preferably straight chain C 3-14 Alkyl, preferably straight chain C 4-12 Alkyl, preferably straight chain C 5-10 Alkyl, preferably straight chain C 6-9 Alkyl, preferably straight chain C 7-8Alkyl. Exemplary linear alkyl includes but is not limited to methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-octadecyl and n-eicosyl. Alternatively, R is a branched alkyl or cycloalkyl, such as isopropyl, sec-butyl, isobutyl, isobutyl, tert-butyl, isopentyl, neopentyl, isohexyl, 2-methylpentyl, 3-methylpentyl, 2-ethylhexyl, 2-propylheptyl, 2-butyloctyl, 2-pentylnonyl, 2-hexyldecyl, 2-heptylundecyl, 2-octyldodecyl, 2-nonyltridecyl, 2-decyltetradecyl, 2-undecylpentadecyl and cyclohexyl. In some embodiments, R is an alkyl substituted with at least one substituent, and the substituent is, for example, an alkoxy, an alkoxycarbonyl, a carboxyl, an amino, a hydroxyl, a sulfhydryl and a halogen. Most preferably, R1 is n-octyl or n-decyl.

[0134] Disadvantages of using common reducing sugars (e.g., dihydroxyacetone, erythrulose) alone as tanning agents include insufficient pigmentation and rapid fading, unnatural orange undertones, and uneven coverage. Surprisingly, it has been found, as will be shown, that a combination of a reducing sugar (A) (e.g., dihydroxyacetone) and an alkyl sulfonate (B) provides an intense, long-lasting artificial tan that retains the original tone of the treated skin.

[0135] Exemplary alkyl sulfonates include, but are not limited to, unsubstituted alkyl sulfonates such as potassium methanesulfonate, potassium trifluoromethylsulfonate, sodium ethylsulfonate, sodium 1-propylsulfonate, sodium 1-butylsulfonate, sodium 1-pentylsulfonate, sodium 1-hexylsulfonate, sodium 1-heptylsulfonate, sodium 1-octylsulfonate, sodium 1-nonylsulfonate, sodium 1-decylsulfonate, sodium 1-undecylsulfonate, sodium 1-dodecylsulfonate, sodium 1-tetradecylsulfonate, sodium 1-pentadecylsulfonate, sodium 1-hexadecylsulfonate, sodium 1-octadecylsulfonate, and sodium cyclohexylsulfonate; substituted alkyl sulfonates such as sodium 2-bromoethylsulfonate, sodium 2-chloroethylsulfonate, sodium 2-hydroxyethylsulfonate, sodium 1 ... sodium salt, 2-hydroxyethylsulfonic acid ammonium salt, 3-hydroxy-1-propylsulfonic acid sodium salt, 3-bromopropylsulfonic acid sodium salt, 3-chloro-2-hydroxypropylsulfonic acid sodium salt, 3-mercapto-1-propylsulfonate sodium, 3-(N-ethyl-3-methylanilino)propylsulfonate sodium, N-ethyl-N-(3-sulfopropyl)-m-anisidine sodium salt, N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3,5-dimethoxyaniline sodium salt, 3-(N,N-dimethyltetradecylammonium)propylsulfonate, 3-(N,N-dimethyloctadecylammonium)propylsulfonate, dioctylsulfosuccinate sodium salt and dicyclohexylsulfosuccinate sodium salt, and mixtures thereof.

[0136] In some embodiments, in addition to or in place of the above-mentioned alkyl sulfonates, alkenyl sulfonates (i.e., R1 of formula (I) is replaced by alkenyl) may be used, such as 1-octene-1-sulfonic acid sodium salt, 2-octene-1-sulfonic acid sodium salt, 1-hydroxy-3,7-dimethyl-6-octene-1-sulfonic acid sodium salt, 1-decene-1-sulfonic acid sodium salt, 1-dodecene-1-sulfonic acid sodium salt, 2-dodecene-1-sulfonic acid sodium salt, 1-tetradecene-1-sulfonic acid sodium salt, and 1-hexadecene-1-sulfonic acid sodium salt.

[0137] In a preferred embodiment, the alkyl sulfonate (B) is sodium 1-octyl sulfonate, sodium 1-decyl sulfonate or both. More preferably, the alkyl sulfonate (B) is sodium 1-octyl sulfonate.

[0138] The stratum corneum is the outermost layer of the skin epidermis containing corneocytes, in which keratin filaments are embedded in a well-structured water-lipid matrix. Keratin swelling may occur when certain chemicals, such as harsh surfactants, penetrate the stratum corneum and interact with keratin, leading to the disruption of the secondary and tertiary structures of keratin and excessive water diffusion. This process also depletes the natural moisturizing components inherent to corneocytes, such as amino acids and lipids. As a result, excessive keratin swelling may cause skin dryness, redness, itching, and irritation.

[0139] As used herein, the relative keratin swelling of a compound is determined by comparing the swelling of the stratum corneum exposed to an aqueous solution containing 2% (w / w%) of the compound relative to the swelling of the stratum corneum exposed to water. For example, the relative keratin swelling can be calculated by the following formula (A):

[0140] Relative keratin swelling,

[0141] Among them, H solution is the height of the stratum corneum when exposed to a test solution containing 2% (w / w%) of the test compound in deionized water; H dry is the height of the stratum corneum before adding the test solution or deionized water; H water is the height of the stratum corneum in deionized water. The height of the stratum corneum in each sample was measured by taking a digital photo of the sample in a test tube rack, uploading the image to ImageJ (NIH) software, and then measuring the distance using its image analysis function (see the experimental details of determining relative keratin swelling in the Examples section).

[0142] The alkyl sulfonates (B) suitable for use in the present disclosure may have a relative keratin swelling of less than 1.28 at a concentration of 2 wt.%, for example from about 0.6, preferably from about 0.62, preferably from about 0.64, preferably from about 0.66, preferably from about 0.68, more preferably from about 0.70, even more preferably from about 0.72, still even more preferably from about 0.74, and up to about 1.2, preferably up to about 1.15, preferably up to 1.1, preferably up to 1.05, preferably up to 1.0, preferably up to 0.95, preferably up to 0.9, preferably up to 0.85, more preferably up to 0.8, even more preferably up to 0.78, yet even more preferably up to 0.76.

[0143] Keratin is divided into α-helical keratin and β-folded keratin according to its secondary structure. Similar to other α-helical proteins, α-helical keratin maintains a stable coiled coil structure. Compared with α-helical keratin, β-folded keratin has more exposed side chains (e.g., disulfide bonds, hydrogen bonds) that are conducive to the insertion of water molecules between sheets. Therefore, β-folded keratin is more swollen than α-helical keratin. The α-helix / β-fold ratio of keratin can be used as an indicator of the swelling ability of keratin. Compounds that produce a larger keratin α-helix / β-fold ratio may have a reduced tendency to cause keratin swelling. Methods for calculating the α-helix / β-fold ratio of keratin are known to those skilled in the art. For example, the ratio can be determined using Raman spectroscopy (e.g., confocal Raman microscopy), IR spectroscopy (e.g., ATR / FT-IR), NMR spectroscopy, and wide-angle X-ray scattering.

[0144] As used herein, the relative α-helix / β-sheet index ratio of a compound is determined by comparing the α-helix / β-sheet index of stratum corneum exposed to an aqueous solution containing 2% (w / w%) of the compound relative to the α-helix / β-sheet index of stratum corneum exposed to water (see the Examples section for experimental details on determining the relative α-helix / β-sheet index ratio).

[0145] The alkyl sulfonates (B) suitable for use in the present invention have a relative α-helix / β-sheet index ratio of greater than 0.86 at a concentration of 2 wt.%, for example at least 0.87, preferably at least 0.88, preferably at least 0.89, preferably at least 0.90, preferably at least 0.91, preferably at least 0.92, more preferably at least 0.93, even more preferably at least 0.93, and up to 0.99, preferably up to 0.98, preferably up to 0.97, more preferably up to 0.96, even more preferably up to 0.95.

[0146] like Figure 7As shown, exposure of keratin to sodium 1-octyl sulfonate (SOS) causes a smaller degree of phase transition from α-helical keratin to β-sheet keratin than exposure to sodium 1-decyl sulfonate (SDS), while sodium lauryl sulfate (SLS) causes the greatest degree of this phase transition among the three. Keratin with a smaller α-helix / β-sheet ratio tends to have a larger available amount of lysine, which is one of the amino acids in the skin that reacts most easily with tanning agents (e.g., dihydroxyacetone) via the Maillard reaction. However, a smaller α-helix / β-sheet ratio may allow more water inside the keratin protein and cause swelling, which would hinder the Maillard reaction. Therefore, compounds that can balance swelling and structural changes (e.g., SOS) can help tanning agents achieve effective color deepening by releasing enough lysine residues but not allowing too much water to enter the keratin protein. Fig.9A It was shown that an increase in the relative α-helix / β-sheet index ratio of the salt from about 0.86 (i.e., SLS) to about 0.97 (i.e., SOS) would increase the degree of skin darkening caused by DHA, but a further increase in the relative α-helix / β-sheet index ratio beyond 0.97 would likely reduce the degree of skin darkening caused by DHA.

[0147] In some embodiments, the alkyl sulfonate (B) is present in an amount of at least about 0.05 wt.%, preferably at least about 0.1 wt.%, preferably at least about 0.5 wt.%, preferably at least about 1 wt.%, more preferably at least about 1.5 wt.%, even more preferably at least about 2 wt.%, and even more preferably at least about 2.5 wt.%, and up to about 10 wt.%, preferably up to about 8 wt.%, preferably up to about 6 wt.%, preferably up to about 5 wt.%, preferably up to about 4 wt.%, more preferably up to about 3.5 wt.%, even more preferably up to about 3 wt.%, and even more preferably up to about 2.75 wt.%, based on the total weight of the topical skin care composition.

[0148] (C) Carrier

[0149] The topical skin care compositions of the present invention may include a carrier (C), which is a material capable of enhancing the uniform delivery and penetration of the tanning agent (and other components of the topical skin care composition) into the skin, thereby achieving a deeper, more vibrant, and longer lasting tan.

[0150] Examples of suitable carriers (C) for use herein include, but are not limited to, benzyl alcohol, 2-phenylethanol, phenoxyethanol, methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, isobutanol, tert-butanol, hexanol, n-octanol, 2-octanol, 2-ethylhexanal, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, and mixtures thereof.

[0151] In some embodiments, the carrier (C) comprises an aromatic alcohol. Due to the presence of a polar end (hydroxyl) and a non-polar end (phenyl), aromatic alcohols (e.g., benzyl alcohol, 2-phenylethanol, phenoxyethanol) can be more effective than other short-chain alkyl alcohols such as ethanol and n-butanol in transdermal delivery of tanning agents (and other components of the topical skin care composition). In addition, benzyl alcohol is particularly advantageous due to its moderate water solubility, aromatic odor, antibacterial properties and low toxicity. In a preferred embodiment, the carrier (C) used herein comprises benzyl alcohol, 2-phenylethanol, 1-phenylethanol, phenoxyethanol, or a mixture thereof. Most preferably, the carrier (C) comprises benzyl alcohol (available from Emerald Kalama Chemical), or consists essentially of benzyl alcohol.

[0152] In some embodiments, the amount of carrier (C) present in the topical skin care composition is at least 0.1 wt.%, preferably at least about 0.5 wt.%, preferably at least about 1 wt.%, preferably at least about 1.5 wt.%, preferably at least about 2 wt.%, and at most about 5 wt.%, preferably at most about 4 wt.%, preferably at most about 3 wt.%, preferably at most about 2.5 wt.%, based on the total weight of the topical skin care composition.

[0153] The weight ratio between the reducing sugar (A) (e.g., dihydroxyacetone), the alkyl sulfonate (B) (e.g., sodium 1-octyl sulfonate, sodium 1-decyl sulfonate), and the carrier (C) (e.g., benzyl alcohol) can be varied depending on the color shade of the tan (e.g., depth, hue angle, color saturation). Typically, however, the weight ratio of alkyl sulfonate (B) to reducing sugar (A) ((B):(A)) is at least 1:20, preferably at least 1:15, preferably at least 1:10, preferably at least 1:8, preferably at least 1:6, preferably at least 1:5, preferably at least 1:4, preferably at least 1:3, more preferably at least 1:2, even more preferably at least 2:3, yet even more preferably at least 1:1, and at most 20:1, preferably at most 15:1, preferably at most 10:1, preferably at most 8:1, preferably at most 6:1, preferably at most 5:1, preferably at most 4:1, preferably at most 3:1, more preferably at most 2:1, even more preferably up to 3:2, yet even more preferably at most 5:4.

[0154] In some embodiments, the weight ratio of alkyl sulfonate (B) to carrier (C) ((B):(C)) is at least 1:4, preferably at least 2:7, preferably at least 1:3, preferably at least 2:5, more preferably at least 1:2, even more preferably at least 2:3, yet even more preferably at least 1:1, and at most 4:1, preferably at most 7:2, preferably at most 3:1, preferably at most 5:2, more preferably at most 2:1, even more preferably at most 3:2, yet even more preferably at most 5:4.

[0155] (D) Organic solvents

[0156] The topical skin care composition may optionally include an organic solvent (D) that is structurally different from the carrier (C). The organic solvent (D) can help dissolve the components that cannot be fully dissolved in the above-mentioned carrier (C), adjust the surface properties of the topical skin care composition to improve processability, viscosity and / or ease of handling, or generally provide a medium suitable for self-tanning operations. Examples of organic solvents that can be used in the present disclosure include, but are not limited to, polyols, such as ethylene glycol, propylene glycol (e.g., 1,3-propylene glycol, 1,2-propylene glycol), butylene glycol (e.g., 1,3-butylene glycol, 1,2-butylene glycol, 1,4-butylene glycol, 2,3-butylene glycol), hexylene glycol, isoprene glycol, diethylene glycol, dipropylene glycol, glycerol, polyol ethers, such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether) and C1 to C4 lower alkanols, such as methanol, ethanol, isopropanol, butanol, and mixtures thereof. In some embodiments, the organic solvent (D) comprises a polyol selected from at least one of 1,3-propylene glycol, 1,2-propylene glycol, ethylene glycol, glycerol, and 1,3-butylene glycol (available from OXEA). In a preferred embodiment, the organic solvent (D) is 1,3-propylene glycol. When present, a polyol (e.g., 1,3-propylene glycol) can also enhance the Maillard reaction by reducing the amount of water that enters the keratin (see Fig. 10A -G).

[0157] Alternatively, a mixture of polyols is used as an organic solvent (D), such as a mixture of a first polyol and a second polyol different from the first polyol. In some embodiments, the first polyol is 1,3-propylene glycol. In some embodiments, the second polyol is glycerol. When a mixture of a first polyol (e.g., 1,3-propylene glycol) and a second polyol (e.g., glycerol) is used, the weight ratio of the first polyol to the second polyol can generally be at least 1:6, preferably at least 1:5, preferably at least 1:4, preferably at least 1:3, more preferably at least 1:2, more preferably at least 1:1, even more preferably at least 3:2, also even more preferably at least 2:1, and at most 10:1, preferably at most 8:1, preferably at most 6:1, more preferably at most 5:1, even more preferably at most 4:1, also even more preferably at most 3:1.

[0158] When present, the amount of organic solvent (D) included in the topical skin care composition can range from at least about 0.2 wt.%, preferably at least about 0.5 wt.%, more preferably at least about 1 wt.%, preferably at least about 2 wt.%, more preferably at least about 3 wt.%, even more preferably at least about 4 wt.%, and even more preferably at least about 5 wt.%, and up to about 20 wt.%, preferably up to about 15 wt.%, preferably up to about 12 wt.%, more preferably up to about 10 wt.%, even more preferably up to about 8 wt.%, and even more preferably up to about 6 wt.%, based on the total weight of the topical skin care composition.

[0159] The weight ratio of carrier (C) (e.g. benzyl alcohol) to organic solvent (D) (e.g. 1,3-propylene glycol, ethylene glycol, glycerol) may range from at least 1:200, preferably at least 1:150, preferably at least 1:100, preferably at least 1:50, preferably at least 1:25, preferably at least 1:20, preferably at least 1:10, more preferably at least 1:8, even more preferably at least 1:6, yet even more preferably at least 1:5, and at most 25:1, preferably at most 20:1, preferably at most 15:1, preferably at most 10:1, preferably at most 5:1, preferably at most 3:1, preferably at most 2:1, preferably at most 1:1, more preferably at most 1:2, even more preferably at most 1:3, yet even more preferably at most 1:4.

[0160] (E) Aromatic sulfonates

[0161] The topical skin care composition of the present disclosure may optionally include an aromatic sulfonate (E). Preferably, the aromatic sulfonate (E) has the formula (II) or a solvate thereof, a tautomer thereof, a stereoisomer thereof, or a mixture thereof,

[0162]

[0163] wherein (i) R2 is an optionally substituted aryl group or an optionally substituted heteroaryl group, and (ii) Y is a cation selected from the group consisting of a hydrogen ion, an ammonium ion and an alkali metal ion.

[0164] The cation Y can be a hydrogen ion, an ammonium ion (i.e. NH4 + ), quaternary ammonium ions (such as tetraethylammonium, tetrabutylammonium), lithium ions, sodium ions, potassium ions and silver ions. Preferably, the aromatic sulfonate (E) is an alkali metal aromatic sulfonate. In a preferred embodiment, Y is an alkali metal ion, such as lithium ions, sodium ions and potassium ions. Most preferably, Y is a sodium ion.

[0165] Aromatic sulfonate (E) can be optionally substituted phenyl sulfonate, optionally substituted naphthyl sulfonate or both. In a preferred embodiment, R2 is an optionally substituted aryl. In some embodiments, R2 is an optionally substituted phenyl. In some embodiments, R2 is an optionally substituted naphthyl. R2 can be substituted with at least one substituent, such as an optionally substituted alkyl, alkoxy, alkoxycarbonyl, carboxyl, amino, hydroxyl, sulfhydryl, halogen, cyano and nitro. Or R2 is unsubstituted.

[0166] In some embodiments, R2 is substituted by at least one straight chain, branched or cyclic alkyl group having at least 1, preferably at least 2, preferably at least 3, preferably at least 4, preferably at least 5 carbon atoms and at most 14, preferably at most 12, preferably at most 10, preferably at most 8, preferably at most 6 carbon atoms. In a preferred embodiment, R2 is substituted by at least one straight chain alkyl group, such as methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-decyl and n-dodecyl. In a preferred embodiment, R2 is substituted by at least one branched alkyl group, such as isopropyl, sec-butyl, isobutyl, isobutyl, tert-butyl, isopentyl, neopentyl and isohexyl. Most preferably, R2 is substituted by methyl or isopropyl.

[0167] Exemplary aromatic sulfonates include, but are not limited to, benzene sulfonates, such as sodium benzene sulfonate, sodium p-toluene sulfonate, sodium cumene sulfonate (i.e., sodium 4-isopropylbenzene sulfonate), sodium 2,3-dimethylbenzene sulfonate, sodium 2,5-dimethylbenzene sulfonate, sodium 2,4,6-trimethylbenzene sulfonate, sodium 4-ethylbenzene sulfonate, sodium 4-propylbenzene sulfonate, sodium 4-tert-butylbenzene sulfonate, sodium 4-chlorobenzene sulfonate, sodium 4-bromobenzene sulfonate, sodium 4-hydroxybenzene sulfonate, sodium dodecylbenzene sulfonate, sodium 3-sulfobenzoate, sodium 4-sulfobenzoate, and sodium 4-tert-butylbenzene sulfonate. Potassium formate, 4-amino-3,5-dibromobenzenesulfonic acid sodium salt, 4-octylbenzenesulfonic acid sodium salt and 4-dodecylbenzenesulfonic acid sodium salt; naphthyl sulfonates such as sodium 1-naphthylsulfonate, sodium 2-naphthylsulfonate, sodium 2-methyl-1-naphthylsulfonate, sodium 4-methyl-1-naphthylsulfonate, sodium 2-butyl-1-naphthylsulfonate, sodium 4-hydroxy-1-naphthylsulfonate, sodium 4-amino-1-naphthylsulfonate, sodium 6-hydroxy-2-naphthylsulfonate and sodium 5-amino-1-naphthylsulfonate, and mixtures thereof.

[0168] In some embodiments, a polymer or oligomer containing an aromatic sulfonate of formula (II) as a repeating unit may be used instead of or in addition to the aromatic sulfonates, such as poly(sodium 4-styrene sulfonate), poly(4-styrene sulfonic acid) ammonium salt, poly(4-styrene sulfonic acid), poly(sodium 2-styrene sulfonate) and sodium polyanisole sulfonate.

[0169] In a preferred embodiment, the aromatic sulfonate (E) is at least one selected from sodium 2-naphthyl sulfonate, sodium p-toluene sulfonate, sodium cumene sulfonate, sodium 4-dodecylbenzene sulfonate and poly (sodium 4-styrene sulfonate), more preferably at least one selected from sodium 2-naphthyl sulfonate (available from Sugai Chemical), sodium p-toluene sulfonate and sodium cumene sulfonate.

[0170] As used herein, the topological polar surface area (tPSA) of a molecule is defined as the sum of the surface contributions of polar atoms (e.g., oxygen and nitrogen atoms, and bound hydrogen atoms) in a molecule. Methods for calculating tPSA are methods known to those skilled in the art (see, for example, Ertl, P., et al., "Fast calculation of molecular polar surface area as a sum of fragment based contributions and its application to the prediction of drug transport properties", J. Med. Chem. 2000, 43, 3714-3717, incorporated herein by reference in its entirety). For example, tPSA can be determined using a desktop computer and commercially available chemical mapping software (e.g., ChemAxon-Marvinview and ChemDraw). Alternatively, tPSA can be found in many chemical databases, such as SciFinder.

[0171] The aromatic sulfonate (E) that can be used in the present invention has a content of less than The topological polar surface area (tPSA) of the substrate is at least about Preferably at least about More preferably, at least about Even more preferably, at least about and at most about Preferably at most about Preferably at most about Preferably at most about More preferably, it is at most about Even more preferably, it is at most about

[0172] As used herein, a hydrogen bond donor site is a functional group with a hydrogen atom that easily forms a covalent bond with an electronegative atom such as oxygen, nitrogen, and sulfur. Exemplary hydrogen bond donor sites include NH functional groups in hydroxyl, carboxylic acid, thiol, sulfonic acid, primary amine, secondary amine, and amide. In some embodiments, the aromatic sulfonate (E) has a maximum of 2 hydrogen bond donor sites, preferably a maximum of 1 hydrogen bond donor site, and more preferably 0 hydrogen bond donor sites.

[0173] Although not wishing to be bound by theory, aromatic sulfonates (E) having lower tPSA values ​​and / or a smaller number of hydrogen bond donors may have better skin penetration and higher skin absorption, which may be advantageous for self-tanning skin care formulations.

[0174] When present, the amount of aromatic sulfonate (E) included in the topical skin care composition can be at least about 0.05 wt.%, preferably at least about 0.1 wt.%, preferably at least about 0.5 wt.%, preferably at least about 1 wt.%, more preferably at least about 1.5 wt.%, even more preferably at least about 2 wt.%, and even more preferably at least about 2.5 wt.%, and at most about 10 wt.%, preferably at most about 8 wt.%, preferably at most about 6 wt.%, preferably at most about 5 wt.%, preferably at most about 4 wt.%, more preferably at most about 3.5 wt.%, even more preferably at most about 3 wt.%, and even more preferably at most about 2.75 wt.%, based on the total weight of the topical skin care composition.

[0175] Without being bound by theory, it is believed that the aromatic sulfonate (E) herein promotes the late Maillard reaction by aiding the polymerization of melanoidins having a higher degree of polymerization and / or conjugation, thereby providing an intensely colored and fade-resistant tan. Surprisingly, it was found that the addition of an aromatic sulfonate (E) to a topical skin care composition containing a reducing sugar (A) (e.g., dihydroxyacetone) and an alkyl sulfonate (B) synergistically promotes the tanning effect of the composition by providing an intense, long-lasting artificial tan with a customizable modified skin tone. Specifically, the use of a combination of reducing sugar (A), alkyl sulfonate (B) and aromatic sulfonate (E) produces a significantly darker tan than the use of a mixture of only reducing sugar (A) and alkyl sulfonate (B), or the use of a mixture of only reducing sugar (A) and aromatic sulfonate (E) (see Fig. 6A -D).

[0176] A customized tan hue can be obtained by varying the weight ratio of the alkyl sulfonate (B) to the aromatic sulfonate (E). These variations allow the topical skin care composition to produce an adjustable depth and degree of hue upon application. In some embodiments, the weight ratio of the alkyl sulfonate (B) to the aromatic sulfonate (E) ((B):(E)) is at least 1:100, preferably at least 1:90, preferably at least 1:80, preferably at least 1:70, preferably at least 1:60, preferably at least 1:50, preferably at least 1:40, preferably at least 1:30, preferably at least 1:20, preferably at least 1:10, more preferably at least 1:8, preferably at least 1:6, preferably at least 1:5, preferably at least 1:4, preferably at least 1:3, or even more preferably at least 1:4. To more preferably at least 1:2, even more preferably at least 1:1, and at most 100:1, preferably at most 90:1, preferably at most 80:1, preferably at most 70:1, preferably at most 60:1, preferably at most 50:1, preferably at most 40:1, preferably at most 30:1, more preferably at most 20:1, preferably at most 10:1, preferably at most 8:1, preferably at most 6:1, preferably at most 4:1, more preferably at most 3:1, even more preferably at most 2:1, and even more preferably at most 3:2.

[0177] (F) Water

[0178] In some embodiments, the topical skin care composition of the present disclosure is an aqueous composition or an oil-in-water (o / w) emulsion in which the continuous phase is aqueous. Therefore, in a preferred embodiment, the topical skin care composition further comprises water (F) in an amount of at least about 10 wt.%, preferably at least about 20 wt.%, preferably at least about 30 wt.%, preferably at least about 40 wt.%, more preferably at least about 50 wt.%, even more preferably at least about 60 wt.%, even more preferably at least about 70 wt.%, and up to about 95 wt.%, preferably up to about 90 wt.%, more preferably up to about 85 wt.%, even more preferably up to about 80 wt.%, based on the total weight of the topical skin care composition.

[0179] (G) Thickener

[0180] The topical skin care composition may optionally include a thickener (G), which may enhance the stability of the composition as well as produce a lubricating skin slipperiness upon application.

[0181] The thickener (G) may comprise a copolymer containing at least one selected from hydroxyalkyl acrylate, acrylic acid salt, acrylamide and acryloyldialkyl taurate as a structural unit. Examples of thickening copolymers include copolymers of hydroxyethyl acrylate and sodium acryloyldimethyl taurate; copolymers of acrylic acid ester and sodium acryloyldimethyl taurate; copolymers of acrylamide and acrylic acid ester; and copolymers of acrylic acid, acrylamide, acrylic acid ester and sodium acryloyldimethyl taurate. Preferably, the thickener (G) contains anionic (co)polymers.

[0182] These thickening copolymers are commercially available, for example from SEPPIC, France. Exemplary thickeners containing copolymers of hydroxyethyl acrylate and acryloyldimethyl taurate include SEPINOV TM EMT 10 (Hydroxyethyl Acrylate / Sodium Acryloyldimethyl Taurate Copolymer), SIMULGEL TM NS (hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, squalane, polysorbate 60), SIMULGEL TM FL (hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, isohexadecane, polysorbate 60), SEPIPLUS TM S (hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, polyisobutene, PEG-7 trimethylolpropane coconut ether) and SIMULGEL TM INS 100 (hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, isohexadecane, polysorbate 60). Exemplary thickeners containing copolymers of acrylates and sodium acryloyldimethyl taurate include SIMULGEL TM EG (sodium acrylate / sodium acryloyldimethyl taurate copolymer, isohexadecane, polysorbate 80), SIMULGEL TM EPG (sodium acrylate / sodium acryloyldimethyl taurate copolymer, polyisobutylene, octyl / decyl glucoside), and SIMULGEL TM SMS 88 (sodium acrylate / acryloyldimethyl taurate / dimethylacrylamide crosspolymer, isohexadecane, polysorbate 60). Examples of thickeners containing acrylamide and acrylate copolymers include SEPIPLUS TM 265 (acrylamide / ammonium acrylate copolymer, polyisobutylene, polysorbate 20). Examples of thickeners comprising a copolymer of acrylic acid, acrylamide, acrylate, and acryloyldimethyl taurate include SEPIPLUS TM 400 (polyacrylate-13, polyisobutylene, polysorbate 20).

[0183] In some embodiments, the thickener (G) contains a copolymer of hydroxyethyl acrylate and sodium acryloyldimethyl taurate. More preferably, the thickener is SEPIPLUS TM S(Hydroxyethyl Acrylate / Sodium Acryloyldimethyl Taurate Copolymer, Polyisobutene, PEG-7 Trimethylolpropane Coconut Ether).

[0184] Other thickening materials may be used in addition to or in place of the above thickening agents, including carbomer (e.g., carbomer 980), C 10-30 Alkyl acrylate crosspolymer (e.g., Pemulen TR-1, Pemulen TR-2 (Acrylates / C 10-30 Alkyl acrylate crosspolymer)), SEPIGEL TM 305(polyacrylamide, C 13-14 Isoparaffin, Laureth-7, SIMULGEL TM A (ammonium polyacrylate, isohexadecane, PEG-40 castor oil), SIMULGEL TM 600 (acrylamide / sodium acryloyldimethyl taurate copolymer, isohexadecane, polysorbate 80), AVC (ammonium acryloyldimethyltaurate / N-vinylpyrrolidone copolymer), AVS (sodium acryloyldimethyltaurate / N-vinylpyrrolidone copolymer) and modified cellulose polymers (eg, hydroxyethylcellulose, methylcellulose).

[0185] Unless otherwise specified, the cationic copolymer used herein refers to a copolymer containing a cationic monomer as one of the repeating units of methacryloylethyl tri(C1-C3 alkyl)ammonium salt or acryloylethyl tri(C1-C3 alkyl)ammonium salt (e.g., acryloylethyl trimethylammonium chloride). Exemplary monomers that can be used to form a cationic copolymer with methacryloylethyl tri(C1-C3 alkyl)ammonium salt or acryloylethyl tri(C1-C3 alkyl)ammonium salt include acrylamide, methacrylamide, tris(hydroxymethyl)-acrylamidomethane, and monomers disclosed in US 7,780,954 (the entire contents of which are incorporated herein by reference).

[0186] In a preferred embodiment, the topical skin care composition is substantially free of cationic copolymers, including substantially free, preferably completely free (ie, 0 wt.%) of the above-mentioned cationic copolymers, such as acrylamide / acryloylethyltrimethylammonium chloride / tris(hydroxymethyl)-acrylamidomethane copolymer.

[0187] (H) Preservatives

[0188] The topical skin care composition may further optionally include a preservative (H). For example, a preservative may be selected to kill bacteria that may persist or breed in the composition, or to prevent the composition from degrading or chemically decomposing (e.g., oxidative degradation). Preservatives suitable for cosmetic preparations are well known to those skilled in the art. In this regard, the selected preservative may vary depending on the specific components present in the topical skin care composition. Examples of suitable preservatives include methylparaben, ethylparaben, propylparaben, EDTA or its salts (e.g., disodium EDTA), phenoxyethanol, DMDM ​​hydantoin, benzyl alcohol, ethyl dibromoglutaronitrile-phenoxyethanol / polyquaternium-7 (Euxyl K-400, Calgon), imidazolidinyl urea, diazolidinyl urea, benzalkonium chloride, benzethonium chloride, sodium benzoate, sorbic acid, etc., or a combination thereof.

[0189] Preferably, the preservative (H) is methylparaben and / or ethylparaben, most preferably a mixture of these preservatives. When present, the amount of preservative (H) included herein may be up to about 5 wt.%, preferably up to about 4 wt.%, preferably up to about 3 wt.%, preferably up to about 2 wt.%, preferably up to about 1 wt.%, preferably up to about 0.5 wt.%, for example, from about 0.001 wt.% to about 3 wt.%, or from 0.1 wt.% to about 1.5 wt.%, or from 0.15 wt.% to about 1 wt.%, or from 0.3 wt.% to about 0.45 wt.%, based on the total weight of the topical skin care composition.

[0190] (I) Acidifier

[0191] The topical skin care compositions disclosed herein may be optionally formulated to include an acidulant (I) for adjusting the pH to a more acidic / less basic. In addition, depending on the chemical structure, the acidulant (I) may act as a chelating agent and / or buffer to neutralize minerals, enhance the activity of any preservatives present, and stabilize active ingredients (e.g., tanning agents).

[0192] The acidulant used herein can be an inorganic acid or an organic acid, specifically including but not limited to hydrochloric acid; orthophosphoric acid; sulfuric acid; carboxylic acids such as fumaric acid and acetic acid; and α-hydroxy acids such as tartaric acid, citric acid, malic acid, lactic acid and glycolic acid, and mixtures thereof. When the acidulant contains an α-hydroxy acid functional group, the acidulant can also help exfoliate and soften wrinkles. Preferably, citric acid is used.

[0193] When present, the amount of acidulant (I) included herein may be up to about 5 wt.%, preferably up to about 4 wt.%, preferably up to about 3 wt.%, preferably up to about 2 wt.%, preferably up to about 1 wt.%, for example, from about 0.001 wt.% to about 3 wt.%, or from 0.02 wt.% to about 2 wt.%, or from 0.1 wt.% to about 1 wt.%, or from 0.2 wt.% to about 0.5 wt.%, based on the total weight of the topical skin care composition. The pH value of the topical skin care composition may vary, but is preferably less than 6.5, for example, at least 2, preferably at least 2.5, more preferably at least 3, even more preferably at least 3.5, and at most 6, preferably at most 5, more preferably at most 4.

[0194] Other optional ingredients

[0195] Various optional ingredients commonly used in topical formulations, such as fragrances, propellants, solvents, adjuvants, anti-aging ingredients, proteins, rheology control agents, dispersants, thickeners, film formers, sequestrants, detergents, vitamins, botanicals and sunscreens, as well as other classes of materials that may be present due to cosmetic, pharmaceutical or other needs, may also be optionally included at their conventional art-determined usage levels. For example, the topical skin care compositions of the present disclosure may be optionally formulated to include one or more fragrances known to those skilled in the cosmetic art to impart a pleasant scent or to help mask any malodorous ingredients that may be present in the topical skin care compositions.

[0196] In a preferred embodiment, the topical skin care composition is substantially free of such optional ingredients, however, when included, non-limiting examples that may be used include film-forming materials such as petrolatum, hydrolyzed wheat protein / wheat oligosaccharides (e.g., Cropeptide W manufactured by Croda Inc.), hydrolyzed corn protein, hydrolyzed wheat protein, hydrolyzed yeast protein, hydrolyzed vegetable protein, hydrolyzed soy protein, hydrolyzed rice protein, and hydrolyzed potato protein; humectants such as glycereth-7 triacetate (Dermol GL-7-A, Alzo), glycerin, glycereth-5 lactate, glycereth-7 diisononanoate; skin conditioning agents and emollients such as mineral oil, cetearyl alcohol, silicones, such as dimethicone, cyclomethicone, phenyl trimethicone, alkyl dimethicone, fluorinated silicones, isononanoates such as ethylhexyl isononanoate, butylene glycol diisononanoate, cetearyl isononanoate, ... isononanoate, cetyl isononanoate, and polyethylene glycol derivatives of castor oil, for example, PEG-40 castor oil (Surfactol 365, available from Vertellus), PEG-45 castor oil, PEG-50 castor oil, PEG-60 castor oil, and PEG-100 castor oil; surfactants such as polyoxyalkylene ethers of fatty alcohols, for example, laureth-3, ceteareth-6, ceteareth-11, ceteareth-15, ceteareth-16, ceteareth-17, ceteareth-18, ceteareth-20, ceteareth-23, ceteareth-25, ceteareth-27, ceteareth-28, ceteareth-30, isoceteth-20, laureth-9 / myreth-9, and PPG-3 octyl ethers, steareths (steareth-2, steareth-4, steareth-6, steareth-7, steareth-10, steareth-11, steareth-13, steareth-15, steareth-20), and polyethylene glycol esters, such as PEG-14 laurate, PEG-15 laurate, PEG-20 laurate, PEG-32 laurate, PEG-75 laurate, PEG-150 laurate or other surfactants; and sunscreens or UV absorbing compounds, such as octyl dimethyl PABA, benzophenone-4, DEA methoxycinnamate, 2-phenyl-benzimidazole-5-sulfonic acid and triethanolamine salicylate.

[0197] In a preferred embodiment, the topical skin care composition comprises 1 to 3 wt.% of a reducing sugar (A) (e.g., dihydroxyacetone, erythrulose), 1 to 3 wt.% of an alkyl sulfonate (B) (e.g., sodium 1-octyl sulfonate, sodium 1-decyl sulfonate), 1 to 3 wt.% of a carrier (C) (e.g., benzyl alcohol), 2 to 8 wt.% of an organic solvent (D) (e.g., 1,3-propylene glycol, 1,2-propylene glycol, ethylene glycol, glycerol, 1,3-butylene glycol) and 70 to 82 wt.% of water (F), based on the total weight of the topical skin care composition, and the balance optionally comprises one or more aromatic sulfonates (E) (e.g., sodium 2-naphthyl sulfonate, sodium p-toluenesulfonate), a preservative (H) (e.g., a mixture of methyl paraben and ethyl paraben), an acidulant (I) (e.g., citric acid) and a thickener (G) (e.g., SEPIPLUS S(Hydroxyethyl Acrylate / Sodium Acryloyldimethyl Taurate Copolymer, Polyisobutene, PEG-7 Trimethylolpropane Coconut Ether).

[0198] In a preferred embodiment, the topical skin care composition comprises, based on the total weight of the topical skin care composition, 1 to 3 wt.% of a reducing sugar (A) (e.g., dihydroxyacetone), 1 to 3 wt.% of an alkyl sulfonate (B) (e.g., sodium 1-octyl sulfonate, sodium 1-decyl sulfonate, or both), 1 to 3 wt.% of a carrier (C) (e.g., benzyl alcohol), 2 to 8 wt.% of an organic solvent (D) (e.g., 1,3-propylene glycol, 1,2-propylene glycol, ethylene glycol, glycerol, 1,3-butylene glycol), 70 to 82 wt.% of water (F), 0.001 to 1 wt.% of a preservative (H) (e.g., a mixture of methyl paraben and ethyl paraben), 0.001 to 0.2 wt.% of an acidulant (I) (e.g., citric acid), and 1 to 3 wt.% of a thickener (G) (e.g., SEPIPLUS TM S(Hydroxyethyl Acrylate / Sodium Acryloyldimethyl Taurate Copolymer, Polyisobutene, PEG-7 Trimethylolpropane Coconut Ether).

[0199] In a preferred embodiment, the topical skin care composition comprises, based on the total weight of the topical skin care composition, 1 to 3 wt.% of a reducing sugar (A) (e.g., dihydroxyacetone), 1 to 3 wt.% of a mixture of alkyl sulfonates (B) (e.g., sodium 1-octyl sulfonate, sodium 1-decyl sulfonate, or both) and an aromatic sulfonate (E) (e.g., sodium 2-naphthyl sulfonate, sodium p-toluene sulfonate, or both) in a previously specified weight ratio, 1-3 wt.% of a carrier (C) (e.g., benzyl alcohol) , 2 to 8 wt.% of an organic solvent (D) (e.g., 1,3-propylene glycol, 1,2-propylene glycol, ethylene glycol, glycerol, 1,3-butylene glycol), 70 to 82 wt.% of water (F), 0.001 to 1 wt.% of a preservative (H) (e.g., a mixture of methyl paraben and ethyl paraben), 0.001 to 0.2 wt.% of an acidulant (I) (e.g., citric acid), and 1 to 3 wt.% of a thickener (G) (e.g., SEPIPLUS TM S(Hydroxyethyl Acrylate / Sodium Acryloyldimethyl Taurate Copolymer, Polyisobutene, PEG-7 Trimethylolpropane Coconut Ether).

[0200] The topical skin care composition herein can be prepared by any method known to those skilled in the art. For example, an aqueous topical skin care composition can be prepared by the following method: (i) in a container of appropriate size, all water-soluble ingredients except a tanning agent (e.g., reducing sugar) are mixed with water under optional heating (e.g., 40 to 90° C., preferably 50 to 85° C., more preferably 75 to 81° C.) and stirring until homogeneous, (ii) in a separate container, all oil phase ingredients (if any) are mixed under optional heating (e.g., 40 to 90° C., preferably 50 to 85° C., more preferably 75 to 81° C.) and stirring until homogeneous, (iii) The homogenous mixture of i) and the homogenous mixture from (ii) (if any) are mixed together, optionally heated (e.g., 40 to 90° C., preferably 50 to 85° C., more preferably 75 to 81° C.) and stirred until a homogenous aqueous composition or a homogenous oil-in-water emulsion is formed, (iv) the homogenous aqueous composition or the homogenous oil-in-water emulsion is cooled, and (v) once cooled, a tanning agent (e.g., a reducing sugar) is added to the homogenous aqueous composition or the homogenous oil-in-water emulsion, optionally stirred under conditions similar to those described above, thereby forming a topical skin care composition. When present, a thickener may be added during step (i) or after step (iii) and before the addition of the tanning agent (i.e., before step (v)). Once cooled, the resulting topical skin care composition may be filled into a desired package. Agitation may be provided by a propeller, such as a high shear mixer and a high-speed dissolver.

[0201] Self-tanning method

[0202] In one or more embodiments, the present invention provides methods of regulating skin color by topically applying a topical skin care composition to the skin of a subject.

[0203] To achieve an acceptable degree of coloration or tanning, a person who desires such coloration or tanning may evenly apply an effective amount of the topical skin care composition over the desired body surface area for an effective application time. Thus, the topical skin care composition may be applied to provide a subtle change in skin color or a more dramatic tanning effect.

[0204] The topical skin care composition can be applied topically to wet or stained skin. Preferably, the desired skin area is cleaned and / or exfoliated prior to application. During application, the topical skin care composition can be applied directly to the epidermis using, for example, the hands, an applicator such as a tissue, a puff, a roller ball, or a spray. The topical skin care composition can be used as a single treatment to color the skin or applied in a gradual manner so that the skin tan becomes more intense in subsequent applications until the desired degree of coloration is achieved.

[0205] The topical skin care composition can be applied to the desired area as needed, preferably 1 to 4 times a day, preferably 2 to 3 times a day. Application can be carried out for at least 1 day, preferably at least 2 consecutive days, more preferably at least 3 consecutive days, even more preferably at least 4 consecutive days, and up to 14 consecutive days, preferably up to 7 consecutive days, more preferably up to 6 consecutive days, even more preferably up to 5 consecutive days. Alternatively, application can be intermittent. Application times outside these ranges can also be used to change the degree of coloring as needed.

[0206] The appearance of a color (e.g., the color of skin) can be described in terms of its hue (color), brightness (brightness), and saturation (vividness). Hue is the primary attribute of color perception used to represent "unique shades" (e.g., red, yellow, blue) that are perceived as completely different hues. Saturation (also called hue or color) refers to the "purity" of a particular hue. Highly saturated hues have vivid, intense colors, while lower saturated hues appear more muted and dull. With no saturation at all, hues become shades of gray. Brightness indicates how bright or dark a color is perceived to be. For example, an image with a higher brightness value reflects a greater amount of light.

[0207] These color attributes (hue, saturation, brightness) can be quantified using various color models including the CIE (International Commission on Illumination) L*a*b* (CIELAB) color space model, the CIE L*C*h° (CIEHCL) color space model, the CIE XYZ model, the RGB color model, etc.

[0208] In some embodiments, the skin color herein is measured using the CIE L*a*b* model, wherein (i) L* represents the lightness of the color, with values ​​ranging from 0 representing black to 100 representing white, (ii) a* represents the red / green value of the color, and (iii) b* represents the yellow / blue value of the color. In some embodiments, the skin color herein is measured using the CIE L*C*h° model, wherein (i) L* represents the lightness of the color, which is the same as L* in the CIE L*a*b* model, (ii) C* represents the saturation (hue), with values ​​ranging from 0 representing no saturation to 60 representing full saturation, and (iii) h° represents the hue angle. As shown in the hue diagram (Figure 11), the hue angle of the skin color herein is expressed in degrees and starts from the +a* axis. Specifically, a hue angle of 0° is red (+a*) and a hue angle of 90° is yellow (+b*). The skin color attribute herein may be measured by a spectrophotometer, such as a CM-700d, CM-2500d or CM-2600d spectrophotometer manufactured by Konica Minolta.

[0209] In some embodiments, the methods disclosed herein produce a vivid, deep, natural, and long-lasting tan on the skin by simultaneously maintaining the original hue of the skin color and increasing the saturation and darkness.

[0210] The methods herein can maintain the original color tone of the skin after application of the topical skin care composition. In some embodiments, the methods herein change the hue angle h° of the skin color by less than 2°, preferably less than about 1.5°, preferably less than about 1.2°, preferably less than about 1°, preferably less than about 0.8°, preferably less than about 0.6°, preferably less than about 0.4°, preferably less than about 0.3°, more preferably less than about 0.2°, even more preferably less than about 0.1°, and even more preferably less than about 0.05° (see Figure 4 ).

[0211] The methods herein can darken the skin color after application of the topical skin care composition. In some embodiments, the methods herein reduce the lightness L* of the skin color by at least about 1%, preferably at least about 2%, preferably at least about 3%, preferably at least about 4%, more preferably at least about 5%, even more preferably at least about 6%, still even more preferably at least about 7%, and up to about 20%, preferably up to about 15%, preferably up to about 12%, more preferably up to about 10%, even more preferably up to about 8%, compared to before topical application.

[0212] In a preferred embodiment, the methods herein simultaneously maintain the hue angle and reduce the lightness of the treated skin according to the ranges specified above.

[0213] It is noteworthy that the combination of reducing sugars (A) (e.g., dihydroxyacetone, erythrulose), alkyl sulfonates (B) (e.g., sodium 1-octane sulfonate, sodium 1-decane sulfonate) provides an unexpected tanning effect (darker color, more durable (i.e., more resistant to fading), more natural coloring) compared to using reducing sugars alone.

[0214] For example, Figure 4 As shown, the use of reducing sugars alone significantly changes the hue angle of the treated skin, and in some cases actually increases the hue angle after prolonged application (e.g., after 7 days of application). The increase in hue angle is often responsible for an orange hue after self-tanning, which is undesirable to many consumers. However, the combination of alkyl sulfonate (B) and reducing sugar (A) effectively maintains the original hue angle, thereby providing a natural tan to the treated skin.

[0215] like Figure 1 As shown, within 24 hours after application, the use of reducing sugar alone results in a reduction in skin brightness of at least 15%, preferably at least 20%, more preferably at least 25%, even more preferably 30%, and at most 60%, preferably at most 50%, more preferably at most 40%, compared to the use of a combination of reducing sugar (A) and alkyl sulfonate (B). In addition, as Figure 3 As shown, the artificial tan produced by this combination faded significantly slower than using reducing sugar alone (eg, less than about 40% faded vs. at least 80% faded after 3 days of fading).

[0216] The methods herein can be used to adjust the color saturation of the skin. In some embodiments, the methods herein increase the saturation C* of the treated skin color by at least about 1%, preferably at least about 2%, preferably at least about 3%, preferably at least about 4%, more preferably at least about 5%, even more preferably at least about 6%, even more preferably at least about 7%, and up to about 20%, preferably up to about 15%, preferably up to about 12%, more preferably up to about 10%, even more preferably up to about 8%, compared to before topical application.

[0217] When aromatic sulfonates (E) are present in topical skin care compositions, the methods herein can provide a synergistic tanning effect by altering the original skin tone and further darkening the skin color. Fig. 6AAs shown in Figure 1-D, the use of a combination of reducing sugar (A), alkyl sulfonate (B) and aromatic sulfonate (E) produces at least 25% more, preferably at least 28% more, more preferably at least 30% more, even more preferably at least 35% more, and up to 60%, preferably up to 50%, more preferably up to 40% more darkening than the use of reducing sugar (A) and alkyl sulfonate (B) alone. In addition, the use of a combination of reducing sugar (A), alkyl sulfonate (B) and aromatic sulfonate (E) produces at least 20% more, preferably at least 25% more, more preferably at least 28% more, even more preferably at least 30% more, and up to 50%, preferably up to 40%, more preferably up to 35% more darkening than the use of reducing sugar (A) and aromatic sulfonate (E) alone. In addition, the presence of aromatic sulfonate (E) imparts an aesthetically pleasing red / bronze hue to the treated skin.

[0218] The following examples are intended to further illustrate the topical skin care compositions and are not intended to limit the scope of the claims.

[0219] Example

[0220] Topical skin care compositions

[0221] Several examples of topical skin care compositions including comparative compositions for tanning performance evaluation are given in Examples 1-2 below. The amount of each component is expressed as a weight percentage relative to the total weight of 100%. DHA refers to dihydroxyacetone, obtained from EMD Millipore. SOS refers to sodium 1-octyl sulfonate. SDS refers to sodium 1-decyl sulfonate. SDBS refers to sodium dodecylbenzene sulfonate. SLSA refers to sodium lauryl sulfoacetate. NSA refers to sodium 2-naphthyl sulfonate, obtained from Sugai Chemical. BA refers to benzyl alcohol, obtained from Kalama. 1,3-Butanediol, methylparaben, ethylparaben and SEPIPLUS TM S were obtained from Oxea, Ueno, Sharon and Seppic respectively. *Indicates that this example is a comparative example in the following table.

[0222] Example 1

[0223] Table 1 Topical skin care composition examples

[0224]

[0225] INCI = International Nomenclature of Cosmetic Ingredients

[0226]

[0227]

[0228] Preparation method

[0229] An exemplary procedure for preparing an example topical skin care composition is as follows:

[0230] Part A: First add deionized water and 1,3-butylene glycol to the main container and mix thoroughly. Heat the main container to a temperature of 75-81°C. When the container temperature reaches 75°C, add parabens, BA and SOS to the main container and mix until clear. Then turn off the heat. Add SEPIPLUS TM S into the main container and mix for about 20 minutes. TM After 30 s, stirring may be optionally increased as the mixture thickens. The main vessel is cooled to a temperature below 40° C., thereby forming Part A.

[0231] Part B: Add deionized water and DHA to a separate container and mix until clear to form Part B.

[0232] After cooling Part A to a temperature below 40°C, add Part B to Part A to form Part AB, which is mixed for about 5 minutes.

[0233] Finally, add citric acid to Part AB to adjust the pH to 3.5-4.0 to form a topical skin care composition.

[0234] Procedure for collecting stratum corneum from the heels of volunteers

[0235] (i) Clean the heel with a cotton swab soaked in alcohol to remove any residue on the skin surface;

[0236] (ii) Wait 5-10 minutes to ensure the skin is dry;

[0237] (iii) Collect the cuticle onto a piece of aluminum foil using a heel bumper* (*It is best to use the following heel bumpers from Panasonic:

[0238] https: / / www.amazon.com / Panasonic-ES2502P-Electric-Heel-Buffer / dp / B001CS69NQ);

[0239] (iv) pooled shavings, especially if the shavings were collected from more than one volunteer; and

[0240] (v) Dry the dandruff at room temperature and humidity for more than 3 hours.

[0241] Determination of relative keratin swelling

[0242] (i) 20 mg of dried stratum corneum powder was added into an appropriate number of NMR tubes (Wilmad-LabGlass WG-1000-7, inner diameter 4.1 mm) to prepare test samples and control samples;

[0243] (ii) placing the NMR tubes in a rack, labeling each tube or position in the rack, placing the rack in a light box, and taking a picture with a digital camera;

[0244] (iii) preparing a sample by preparing an aqueous solution containing deionized water and 2% (w / w%) of the compound to be tested and adding 1.5 mL of the solution to an appropriately labeled NMR tube;

[0245] (iv) Prepare a control sample by adding 1.5 mL of deionized water to an appropriately labeled NMR tube;

[0246] (v) Gently shake each NMR tube sample by hand, but without inverting it, for about 1 minute to evenly disperse the stratum corneum powder in the solution;

[0247] (vi) Seal the NMR tube, place it in a tube rack, and place the tube rack in a temperature-controlled chamber at 40° C. for 1 hour;

[0248] (vii) Afterwards, the tube rack containing all samples was placed in a light box and photographed using a digital camera;

[0249] (viii) measuring the height of the stratum corneum powder of each sample using the image analysis function in ImageJ (NIH) software; and

[0250] (ix) Calculate the keratin swelling property of the test compound according to the following formula (A):

[0251] Relative keratin swelling,

[0252] Among them, H solution is the height of the stratum corneum when exposed to a test solution containing 2% (w / w%) of the test compound in deionized water; H dry is the height of the stratum corneum before adding the test solution or deionized water; H water is the height of the stratum corneum in deionized water.

[0253] Determination of relative α-helix / β-sheet index ratio

[0254] (i) 20 mg of dried stratum corneum powder was added into an appropriate number of NMR tubes (Wilmad-LabGlass WG-1000-7, inner diameter 4.1 mm) to prepare test samples and control samples;

[0255] (ii) placing the NMR tubes in a tube rack and labeling the position of each tube or tube in the rack;

[0256] (iii) preparing a sample by preparing an aqueous solution containing deionized water and 2% (w / w%) of the compound to be tested and adding 1.5 mL of the solution to an appropriately labeled NMR tube;

[0257] (iv) Prepare a control sample by adding 1.5 mL of deionized water to an appropriately labeled NMR tube;

[0258] (v) Gently shake each NMR tube sample by hand, but without inverting it, for about 1 minute to evenly disperse the stratum corneum powder in the solution;

[0259] (vi) sealing the NMR tube, placing it in a tube rack, and placing the tube rack in a temperature-controlled chamber at 40° C. for 96 hours;

[0260] (vii) Afterwards, gently shake each NMR tube sample by hand, but without inverting, for approximately 1 minute;

[0261] (viii) Remove the supernatant, add 1.5 mL of deionized water to the tube, and leave at room temperature for more than 15 min;

[0262] (ix) repeating step (viii) twice more;

[0263] (x) scrape off the stratum corneum with a spatula and transfer to a clean 8-dram bottle;

[0264] (xi) drying the stratum corneum under indoor mild and humid conditions for more than 12 hours;

[0265] (xii) Thereafter, each dried sample was analyzed by FT-IR (Nicolet iS50, ThermoFisher Scientific Inc., MA, USA) equipped with a ZeSe ATR accessory and a DTGS detector. -1 The resolution is between 4000 and 650 cm -1 Scan 32 times within the wave number range; and

[0266] (xiii) Spectra were analyzed using homemade software (S. Takada, S. Naito, J. Sonoda, Y. Miyauchi. Non-invasive in vitro measurement of natural moisturizing factor content instratum corneum of human skin by attenuated total reflection infrared spectroscopy. Applied Spectroscopy 2012; 66: 26-32, incorporated herein by reference in its entirety) to provide α-helix / β-sheet indices corresponding to changes in protein secondary structure (H. Takahashi, H. Tsuji, M. Minami-Hori, Y. Miyauchi, H. Iizuka, Defective barrier function accompanied by structural changes of psoriatic stratum corneum, The Journal of Dermatology, 2014; 41: 144-148, incorporated herein by reference in its entirety). The relative α-helix / β-sheet index ratio of the test sample is calculated by dividing the α-helix / β-sheet index of the test sample by the α-helix / β-sheet index of the control sample.

[0267] Evaluation methods for topical skin care compositions

[0268] Skin test

[0269] The composition of the embodiment was 2 mg / cm 2 The amount of the product to be tested was applied to the skin. The color parameters of the skin (e.g., lightness L*, hue angle h°) were measured before application of each test and at specific different time points after application of the product to be tested, and then the change (ΔL*, (ΔC*, Δh°) of each parameter compared to before application was calculated. Specifically, CM-2600d manufactured by Konica Minolta was used as a colorimeter.

[0270] Skin testing can be performed as a consumer home use study. For example, Figure 3 and 4Data from the study. Consumers applied a lotion containing either DHA alone ("Control DHA") or DHA and SOS ("+SOS") to their arms and legs once daily for 7 days. Color measurements were taken on the arms and legs at baseline (Day 0), Day 3, and Day 7. Starting on Day 7, the panel of subjects stopped using the test products. Additional color measurements were taken on the arms and legs on Day 10.

[0271] Regardless of whether an embodiment or element presented herein is explicitly stated or not, the present disclosure also contemplates other embodiments that "comprise," "consist of," and "consist essentially of."

[0272] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It should therefore be understood that within the scope of the appended claims, the present invention may be practiced in ways other than those specifically described herein.

[0273] All of the above patents and other references are incorporated herein by reference in their entirety as if fully set forth.

Claims

1. A topical skin care composition, wherein: Include: (A) 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition, (B) optionally substituted C 8-12 Alkyl sulfonates, and (C) a carrier, The reducing sugar (A) is any reducing sugar that can react with amino acids present in the skin to cause skin darkening, The optionally substituted C 8-12 The weight ratio of alkyl sulfonate (B) to reducing sugar (A) (B): (A) is 1:20 to 20:

1.

2. The topical skin care composition according to claim 1, wherein The optionally substituted C 8-12 The alkyl sulfonate (B) is an unsubstituted alkyl sulfonate.

3. The topical skin care composition according to claim 1 or 2, wherein The optionally substituted C 8-12 The alkylsulfonate (B) is an alkali metal salt of an alkylsulfonic acid.

4. The topical skin care composition according to claim 1 or 2, wherein The optionally substituted C 8-12 The weight ratio of alkyl sulfonate (B) to reducing sugar (A) (B): (A) is 1:15 to 15:

1.

5. The topical skin care composition according to claim 1 or 2, wherein The reducing sugar (A) is dihydroxyacetone, erythrulose or both.

6. The topical skin care composition according to claim 1 or 2, wherein: The carrier (C) contains an aromatic alcohol.

7. The topical skin care composition according to claim 1 or 2, wherein: The carrier (C) comprises benzyl alcohol.

8. The topical skin care composition according to claim 1 or 2, wherein: The invention further comprises (D) an organic solvent having a structure different from that of the carrier (C).

9. The topical skin care composition according to claim 8, wherein The organic solvent (D) is at least one selected from 1,3-propylene glycol, 1,2-propylene glycol, and 1,3-butylene glycol.

10. The topical skin care composition according to claim 1 or 2, wherein: Further comprising (E) an aromatic sulfonate, wherein the aromatic sulfonate (E) has a value less than Topological polar surface area tPSA.

11. The topical skin care composition according to claim 10, wherein The aromatic sulfonate (E) is an optionally substituted phenyl sulfonate, an optionally substituted naphthyl sulfonate, or both.

12. The topical skin care composition of claim 10, wherein The weight ratio of the alkyl sulfonate (B) to the aromatic sulfonate (E), (B):(E), is 1:100 to 100:

1.

13. A method for darkening and maintaining the skin tone of a subject, wherein: The method comprises: Topically applying the topical skin care composition according to any one of claims 1 to 12 to the skin of a subject, Therein, the topical application reduces the lightness L* of the color by at least 10% compared to before the topical application, and the change in the hue angle h° of the color is less than 2°.

14. A method for darkening the skin color of a subject, wherein: The method includes: Topically applying the topical skin care composition according to any one of claims 1 to 12 to the skin of a subject, Therein, the topical application reduces the lightness L* of the color by at least 10% compared to before the topical application.

15. A method for adjusting the color saturation of a subject's skin, wherein: The method includes: Topically applying the topical skin care composition according to any one of claims 1 to 12 to the skin of a subject, Wherein the topical application increases the saturation C* of the color by at least 10% compared to before the topical application.

16. A range of topical skin care products for retail sale, wherein: The series includes: (a) a first topical skin care composition comprising: (A) 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition, (B) optionally substituted C 8-12 Alkyl sulfonates, and (C) a carrier, wherein the optionally substituted C 8-12 The weight ratio of alkyl sulfonate (B) to reducing sugar (A) (B): (A) is 1:20 to 20:1; and (b) a second topical skin care composition comprising: (A) 0.1-30 wt.% of reducing sugar relative to the total weight of the topical skin care composition, (B) optionally substituted C 8-12 Alkyl sulfonates, and (C) a carrier, wherein the optionally substituted C 8-12 The weight ratio of alkyl sulfonate (B) to reducing sugar (A) (B): (A) is 1:20 to 20:1, wherein the content of reducing sugar (A) present in the first topical skin care composition (a) is less than the content of reducing sugar (A) present in the second topical skin care composition (b), and wherein the content is each content relative to the total weight of the first and second topical skin care compositions.

17. A series as claimed in claim 16, wherein: The first topical skin care composition (a) and the second topical skin care composition (b) are packaged separately.

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