HK1200737B - Method for lightening skin - Google Patents

Description

Method for lightening skin

The application is a divisional application of an invention patent application, the application date of the parent application is 2009, 6 and 4, the application number is 200980122854.4 (PCT/EP2009/056886), and the invention name is 'composition for lightening skin color'.

Technical Field

The present invention relates to skin lightening additives and compositions comprising the same. More particularly, the present invention relates to a cosmetic composition comprising a skin lightening additive, wherein the skin lightening additive comprises a hetero-substituted saturated or unsaturated aliphatic acid, or mixtures thereof. The skin lightening additive results in a cosmetic composition that can provide a moisturization benefit when used. In addition, it has been unexpectedly found that such aliphatic acids provide skin lightening benefits when applied topically.

Background

Many consumers are concerned with the characteristics of their skin. For example, consumers may be concerned with the degree of pigmentation of their skin, freckles and/or age spots. Other consumers desire to reduce skin darkening caused by exposure to sunlight. To meet the needs of consumers, many attempts have been made to develop products that improve skin characteristics. The products developed to date tend to have low efficacy, have undesirable side effects, or both. In addition, such products can be expensive and are not generally an option for low-income consumers.

There is an increasing interest in developing a cosmetic composition comprising new skin lightening additives. The present invention relates to cosmetic compositions comprising new skin lightening additives. The cosmetic compositions of the present invention preferably comprise as lightening additive a compound such as 12-hydroxystearic acid, ricinoleic acid or both. Comparison of MelanoDerm treated with compositions having newly discovered skin lightening additives of the present invention^TMCulture and MelanoDerm not treated therewith^TMThe cosmetic composition of the invention results in a reduction of melanin content when cultured, which reduction is at least8% (preferably by at least about 11%).

And (3) supplementary information:

efforts have been made to prepare skin care cosmetic compositions. Skin lightening agents with 4-substituted resorcinol derivative compounds are disclosed in US 6875425.

Other efforts have been disclosed to prepare skin treatment compositions. Methods of treating skin with skin lightening agents are disclosed in US 7250158 and US 7247294.

Other efforts have been disclosed directed to treating skin. In US 5998423, compositions with polycyclic nitrogen heterocycles are disclosed.

None of the supplementary information above discloses a skin lightening composition comprising a heterosubstituted saturated or unsaturated aliphatic acid, or mixtures thereof, as a lightening additive.

Disclosure of Invention

In a first aspect, the present invention relates to a skin lightening additive comprising a hetero-substituted saturated or unsaturated aliphatic acid, or both.

In a second aspect, the present invention relates to a cosmetic composition for skin lightening comprising a skin lightening agent comprising the skin lightening additive of the first aspect of the invention.

In a third aspect, the present invention is directed to a method of lightening skin with the cosmetic composition of the second aspect of the present invention.

All other aspects of the invention will become apparent from the detailed description and the examples which follow.

As used herein, "reducing melanin content" means that melanin content is reduced when comparing two three-week-old cultures of MatTek MelanoDerm that were not treated with a composition comprising the skin lightening additive of the present invention with two three-week-old cultures of MatTek MelanoDerm that were treated with a composition comprising the skin lightening additive of the present invention, wherein treatment means:

(a) loading said MelanoDerm culture in a six-well tissue culture dish and leaving said tissue culture dish approximately 0.3cm empty;

(b) contacting said MelanoDerm culture with 0.1-5 micromoles of a composition having a skin lightening additive of the invention, said composition being prepared from a 10 millimolar solution of the skin lightening additive and a carrier (e.g. dimethyl sulfoxide) diluted with Dulbecco's Modified EagleMedia;

(c) treated and untreated cultures were compared by obtaining the mean melanin content (expressed as micrograms) by extracting melanin from MelanoDerm and obtaining an absorbance reading (OD 490) at 490nm using a commercially available spectrophotometer such as a Hach spectrophotometer.

As used herein, "cosmetic composition" is intended to include compositions for topical application to mammalian, especially human, skin. Such compositions may be broadly classified as leave-on or rinse-off, and are intended to include conditioners or supplements, lipsticks, color cosmetics and general topical compositions in a format that at least reduces the effects of melanin on keratinocytes. As used herein, "lightening" and "whitening" are meant to be the same and include direct lightening of the skin and lightening of spots on the skin such as age spots and freckles. "Dulbecco's Modified Eagle Media" refers to a nutrient solution sold by MatTek Corporation, which is processed and used according to the instructions provided, said product being marketed as MEL 30010 BBLLMM. Skin lightening additive refers to a component for causing physical whitening, especially biological whitening (i.e., reducing melanin production), and thus the skin lightening additive may comprise, may consist essentially of, or consist of a skin lightening additive. "MelanoDerm" refers to a product having normal human epidermal keratinocytes and melanocytes, which have been cultured in the form of human epidermal fine cellsHighly differentiated models of multilayers of cells, all of which are commercially available from mattek corporation. As used herein, "unsaturated" means having at least one non-sp³A hybrid bond. As used herein, "comprising" is intended to include "consisting essentially of and" consisting of.

The cosmetic composition of the present invention may be in the form of: liquid, lotion, cream, serum, gel, soap bar or toner, or by mask or patch application. The compositions of the present invention are compositions that at least lighten the skin, "skin" is intended to include skin on the face, neck, chest, back, arms, hands, legs, and scalp. All ranges specified herein are intended to implicitly include all ranges subsumed therein if, for example, such ranges are not explicitly specified.

Detailed Description

The only limitation of the skin lightening additive useful in the present invention is that it can be used in topical compositions suitable for use in humans. Preferred additives are hetero-substituted saturated or unsaturated aliphatic acids, or mixtures thereof.

In a most preferred embodiment, the skin lightening additive for use in the present invention comprises a compound having the formula:

or a mixture thereof,

wherein each R is independently hydrogen, hydroxy, C1-6 alkoxy, C1-6 alkyl, aralkyl, or amine, provided that at least one R group includes a heteroatom; each R is¹Independently hydrogen, C1-6 alkoxy, C1-6 alkyl, aralkyl or amine; n is an integer from 7 to 19; s and e are each independently an integer from 0 to 8, where s + e>6; q is an integer from 6 to 11; each r is independently an integer from 0 to 1, provided that r is not 1 when x is 1; x is an integer of 0 to 1, with the proviso that when at least one r isX is 0 at 1; and each t is independently an integer from 1 to 7.

Preferred compounds suitable for use in the present invention, alone or in mixtures, are laccaic acid, 9,10, 18-trihydroxyoctadecanoic acid (phloionolic acid), 9,10, 13-trihydroxy-11-octadecenoic acid, 9, 13-dihydroxy-12-ethoxy-10-octadecenoic acid, 9-hydroxy-10, 12-octadecadienoic acid, 4, 14-dihydroxy-octadecanoic acid, 12-hydroxystearic acid (12-hydroxyoctadecanoic acid), 14-hydroxy-cis-11-eicosenoic acid (lesquerolic acid), ricinoleic acid, flavodecanoic acid and ricinoleic acid (12-hydroxy-9-cis-octadecanoic acid), as shown in formulae I or II. Other preferred compounds suitable for use in the present invention include beta-9-hydroxy-10, 12-octadecadienoic acid (beta-dimorphicolic acid), 12-hydroxy-9, 15-octadecadienoic acid (densipolicic acid), 8-methoxy-13-hydroxy-9, 11-octadecadienoic acid, 7-oxo-octadecanoic acid, 9-oxo-octadecanoic acid, 12-oxo-octadecanoic acid and 10-oxo-14-methyl-pentadecanoic acid, as shown in structure III. In addition, the scope of the present invention includes any derivatives (e.g., ester derivatives) and/or salts of the acids of formulas I-III, especially the Mg, Na and/or Ca salts thereof.

The cosmetic compositions of the present invention generally comprise from 0.001 to 15%, preferably from 0.1 to 12%, and most preferably from 1 to 10% by weight of the skin lightening additive, based on the total weight of the cosmetic composition, and also includes all numerical ranges subsumed therein.

Although it is within the scope of the present invention that the skin lightening additive consists essentially of, and consists of: the hetero-substituted saturated or unsaturated aliphatic acid or mixtures thereof, but in one generally desirable embodiment the skin lightening additive of the present invention comprises from 0.2 to 95 weight percent, preferably from 10 to 85 weight percent, and most preferably from 30 to 65 weight percent of the hetero-substituted saturated or unsaturated aliphatic acid or mixtures thereof, based on the total weight of the skin lightening additive, and all numerical ranges subsumed therein.

In another desirable embodiment, the cosmetic composition of the present invention comprises from 2 to 9% by weight, preferably from 3 to 8% by weight, most preferably from 3 to 6% by weight, based on the total weight of the cosmetic composition of the present invention, of a heterosubstituted saturated or unsaturated aliphatic acid or mixtures thereof, including all numerical ranges subsumed therein.

When used in combination, the weight ratio of heterosubstituted saturated or unsaturated aliphatic acid to heterosubstituted saturated aliphatic acid is from 5:95 to 95:5, preferably from 20:80 to 80:20, most preferably from 40:60 to 60:40, and includes all numerical ranges subsumed therein.

It will be appreciated that commercially available and conventional excipients may be used as diluents, dispersants and/or carriers for the skin lightening agent and additives described herein, as well as any other optional but often preferred additives. Thus, the cosmetically acceptable vehicle suitable for use in this invention may be water-based, anhydrous or an emulsion, with water-in-oil or oil-in-water emulsions generally being preferred. If water is desired, it will generally comprise the balance of the cosmetic composition, preferably from 5 to 99% by weight, most preferably from 40 to 80% by weight of the cosmetic composition, and including all numerical ranges subsumed therein.

In addition to water, the compositions of the present invention may optionally comprise an organic solvent as a carrier or co-carrier. Illustrative, non-limiting examples of the types of organic solvents suitable for use in the present invention include alkanols such as ethanol and isopropanol, mixtures thereof, and the like.

Other suitable optional additives include ester oils such as isopropyl myristate, cetyl myristate, 2-octyldodecyl myristate, avocado oil, almond oil, olive oil, neopentyl glycol dicaprate, mixtures thereof, and the like. Such ester oils generally assist in emulsifying the cosmetic compositions of the present invention, often in amounts effective to produce a stable emulsion, most preferably a water-in-oil emulsion.

Emollients may also be used as carriers in the cosmetic compositions of the present invention, if desired. It is often desirable to use alcohols such as 1-cetyl alcohol (i.e., cetyl alcohol) and phenoxyethanol as emollients, and are also generally classified as silicone oils and synthetic esters. Suitable silicone oils include cyclic or linear polydimethylsiloxanes containing from 3 to 9, preferably from 4 to 5, silicon atoms. The nonvolatile silicone oils useful as emollient materials in the cosmetic compositions of the present invention described herein include polyalkyl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers. The substantially nonvolatile polyalkyl siloxanes useful herein include, for example, polydimethylsiloxane.

Ester emollients which may optionally be used are:

(1) alkenyl or alkyl esters of fatty acids having 10 to 20 carbon atoms. Examples thereof include isoeicosyl pivalate, isononyl isononanoate, oleyl myristate, oleyl stearate, and oleyl oleate.

(2) Ether-esters, such as fatty acid esters of ethoxylated fatty alcohols.

(3) A polyol ester. Ethylene glycol mono and di-fatty acid esters, diethylene glycol mono and di-fatty acid esters, polyethylene glycol (200-6000) mono-and di-fatty acid esters, propylene glycol mono-and di-fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono-and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl monostearate, 1, 3-butylene glycol distearate, polyoxyethylene polyhydroxy fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters.

(4) Wax esters such as beeswax, spermaceti, stearyl stearate and arachidyl behenateAn acid ester.

(5) Sterol esters, an example of which is cholesterol fatty acid esters.

Emollients are generally used in amounts of 0.1 to 50% by weight of the cosmetic composition, including all numerical ranges subsumed therein.

Fatty acids having from 10 to 30 carbon atoms may also be included in the compositions of the present invention as cosmetically acceptable carriers. Examples of such fatty acids include pelargonic, lauric, myristic, palmitic, stearic, isostearic, oleic, linoleic, arachidic, behenicAcids or erucic acids, and mixtures thereof. Compounds believed to enhance skin penetration, such as dimethyl sulfoxide, may also be used as optional carriers.

Humectants of the polyhydric alcohol type may also be employed in the cosmetic compositions of the present invention. Humectants often help to enhance the efficacy of emollients, reduce scaling, promote removal of accumulated dirt, and improve skin feel. Typical polyhydric alcohols include glycerol, polyglycols, more preferably alkylene polyols and their derivatives, including propylene glycol, dipropylene glycol ethers, polypropylene glycol, polyethylene glycol and derivatives thereof, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1, 3-butylene glycol, 1,2, 6-hexanetriol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. For best results, the humectant is preferably propylene glycol or sodium hyaluronate. The humectant may be present in any amount ranging from 0.2 to 25% by weight, preferably from 0.5 to 15% by weight, based on the total weight of the cosmetic composition, including all ranges subsumed therein.

Thickeners may also be used as part of the cosmetically acceptable carrier in the cosmetic compositions of this invention. Typical thickeners include cross-linked acrylates (e.g. Carbopol 982), hydrophobically modified acrylates (e.g. Carbopol 1382), cellulose derivatives, and natural gums. Among useful cellulose derivatives are sodium carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, ethyl cellulose, and hydroxymethyl cellulose. Natural gums suitable for use in the present invention include guar gum, xanthan gum, sclerotium, carrageenan, pectin and combinations of these gums. The amount of the thickener may be 0.0 to 5% by weight, usually 0.001 to 1% by weight, and optimally 0.01 to 0.5% by weight.

Water, solvents, silicones, esters, fatty acids, humectants and/or thickeners in total constitute from 1 to 99.9% by weight, preferably from 80 to 99% by weight, of the cosmetically acceptable carrier.

The cosmetic composition of the present invention may also contain a surfactant. The total concentration of surfactants ranges from 0 to 40% by weight of the composition, preferably from 0 to 20% by weight, optimally from 0 to 5% by weight. The surfactant may be selected from anionic, nonionic, cationic and amphoteric actives. Particularly preferred nonionic surfactants are the C10-C20 fatty alcohols or acid hydrophobes which are condensed with 2-100 moles of ethylene oxide or propylene oxide per mole of hydrophobe; a C2-C10 alkylphenol condensed with 2-20 moles of an alkylene oxide; mono-and di-fatty acid esters of ethylene glycol; fatty acid monoglycerides; sorbitan, mono-and di-C8-C20 fatty acids; block copolymers (ethylene oxide/propylene oxide); and polyoxyethylene sorbitan, and combinations thereof. Alkyl polyglycosides and sugar fatty amides (e.g., methyl glucamide) are also suitable nonionic surfactants.

Preferred anionic surfactants include soaps, alkyl ether sulfates and sulfonates, alkyl sulfates and sulfonates, alkylbenzene sulfonates, alkyl and dialkyl sulfosuccinates, C8-C20 acyl isothionates, acyl glutamates, C8-C20 alkyl ether phosphates, and combinations thereof.

Fragrances may be used in the cosmetic compositions of the present invention. Non-limiting examples of classes of fragrances that may be used include those comprising terpenes and terpene derivatives, such as those described in Common Fragrance and flavor materials, VCH Publishers (1990), by Bauer, k.

Still further illustrative, non-limiting examples of the types of fragrances that may be used in the present invention include myrcene, dihydromyrcene alcohol, citral, tagetenone, cis-geranic acid, citronellac acid or cis-geranonitrile, mixtures thereof, and the like.

Preferably, the amount of fragrance used in the cosmetic composition of the present invention is 0.0 to 10wt%, more preferably 0.00001 to 5wt%, most preferably 0.0001 to 2 wt%.

Various types of optional additional active ingredients may be used in the cosmetic compositions of the present invention. "active ingredient" is defined as a skin benefit agent other than emollients and other ingredients that merely improve the physical characteristics of the composition. Although not limited to this category, typical examples include talc and silica, as well as alpha-hydroxy acids, beta-hydroxy acids, peroxy compounds, zinc salts, and sunscreens.

Beta-hydroxy acids include, for example, salicylic acid. Zinc pyrithione is an example of such zinc salts for use in the cosmetic compositions of the present invention.

Sunscreens include materials commonly used to block ultraviolet light. Exemplary compounds are derivatives of PABA, cinnamate and salicylate. For example, butylmethoxydibenzoylmethane (avobenzophenone) (Parsol 1789) can be used^®) Octyl methoxycinnamate and 2-hydroxy-4-methoxybenzophenone (also known as oxybenzone). Octyl methoxycinnamate and 2-hydroxy-4-methoxybenzophenone are commercially available under the trademarks Parsol MCX and Benzophenone-e, respectively. The precise amount of sunscreen used in the composition may vary depending on the degree of protection desired from the sun's ultraviolet radiation. Additives that reflect or scatter solar rays may also be used. These additives include oxides such as zinc oxide and titanium dioxide.

Many cosmetic compositions, especially those containing water, should be protected from the growth of potentially harmful microorganisms. Antimicrobial compounds, such as triclosan (triclosan), and preservatives are often necessary. Suitable preservatives include alkyl esters of p-hydroxybenzoic acid, hydantoin derivatives, propionate salts, and various quaternary ammonium compounds. Particularly preferred preservatives of the present invention are methyl paraben, propyl paraben, phenoxyethanol and benzyl alcohol. Preservatives are generally used in amounts of 0.1 to 2% by weight of the composition.

Additional other optional ingredients useful in the cosmetic compositions of the present invention include diacids (e.g., malonic acid and sebacic acid), antioxidants such as vitamin E, vitamins such as niacinamide and vitamin C and derivatives thereof, resorcinol and derivatives thereof (including those esterified with, for example, ferulic acid, vanillic acid, and the like), and retinoids including retinoic acid, retinal, retinol and retinyl esters, conjugated linoleic acid, petroselinic acid, and mixtures thereof, as well as any other known conventional ingredient for reducing wrinkles, skin whitening, eliminating acne, and reducing the effects of sebum.

The cosmetic compositions of the present invention are intended to be used primarily as products for topical application to human skin, in particular at least as products for lightening said skin. Thus, the inventors have found that the aliphatic acid has excellent skin lightening capabilities, so that it can be used as a skin lightening additive in topical cosmetic compositions that are topically applied to the area of the skin where lightening or whitening is desired. Other benefits may include moisturizing the skin, reducing the effects of sebum on the skin, and reducing skin wrinkles. Typically, the cosmetic compositions of the present invention have a melting point of from 30 to 45^oC, including all ranges subsumed therein. In a particularly preferred embodiment, the cosmetic composition of the present invention has a pH of from 4.5 to 7.5, including all ranges subsumed therein.

In preparing the cosmetic composition of the present invention, the temperature is 70 to 80 deg.C^oC, mixing the desired components under atmospheric pressure, in no particular order.

The packaging for the composition of the invention may be a patch, bottle, tube, bead applicator, propellant-driven aerosol device, squeeze container or lidded can.

The examples which follow are provided to illustrate and aid in the understanding of the invention. The examples are not intended to limit the scope of the claims.

Examples

Commercially available human skin equivalents (MelanoDerm from MatTek) were obtained^TM) A solution with a final concentration of 0.1-5 micromolar was prepared from 10 millimolar dimethyl sulfoxide stock solution, and fed ten times over a three week period to the medium of a MelanoDerm culture^oC, and during the feeding, in a humidified 5% carbon dioxide bacteria incubator, but removed when the feeding is performed.

After a period of three weeks, MelanoDerm cultures were removed and incubated at 60^oIn an oven, C, in sixteen hours (overnight), dissolve in centrifuge tubes containing 250 microliters of dissolution reagent (GNE 9100, Packard). After solubilization, the centrifuge tube with sample is spun at 12,000g for five minutes. Remove 200. mu.l of supernatant and place in a 96-well plate. The absorbance of the supernatant was measured at 490nm with a spectrophotometer. A standard curve using synthetic melanin was established in parallel to quantify melanin in micrograms in a sample. The results are provided below:

table:

i = ricinoleic acid (0.1 μ M),

i i = 12-hydroxystearic acid (5 μ M),

MC = melanin content,

the results relate to MelanoDerm cultures, which show that cosmetic compositions with the aliphatic acids of the invention unexpectedly result in skin lightening.

Claims (30)

1. A method for lightening the skin for a non-therapeutic purpose, comprising the steps of:

a) determining a skin in need of skin lightening;

b) contacting the skin with a composition comprising:

0.001 to 15% by weight of a skin lightening hetero-substituted saturated aliphatic acid additive consisting of 12-hydroxystearic acid and/or salts thereof, and

a cosmetic carrier; and

c) the skin is brightened,

the composition optionally comprises an additional component selected from niacinamide, dibasic acids, resorcinol, ricinoleic acid, hetero-substituted unsaturated aliphatic acids and/or salts and/or esters thereof, and mixtures thereof,

wherein the hetero-substituted unsaturated aliphatic acid is a compound having the formula:

or mixtures thereof, wherein each R is independently hydrogen, hydroxy, C_1-6Alkoxy radical, C_1-6Alkyl, aralkyl or amine, provided that at least one R group includes a heteroatom; each R is¹Independently of each other is hydrogen, C_1-6Alkoxy radical, C_1-6Alkyl, aralkyl or amine; s and e are each independently an integer from 0 to 8, where s + e.gtoreq.6; q is an integer from 6 to 11; each r is independently an integer from 0 to 1, provided that r is not 1 when x is 1; x is an integer from 0 to 1, provided that x is 0 when at least one r is 1; and each t is independently an integer from 1 to 7.

2. The method of claim 1, wherein the diacid is present and is selected from malonic acid and sebacic acid.

3. The method of claim 1, wherein the composition further comprises an alpha hydroxy acid, a beta hydroxy acid, a sunscreen, or mixtures thereof.

4. The method of claim 1, wherein the composition further comprises conjugated linoleic acid, petroselinic acid, or both.

5. The method of claim 1, wherein the composition further comprises vitamin E.

6. The method of claim 1, wherein the composition comprises a component selected from the group consisting of: laccaic acid, 9,10, 18-trihydroxyoctadecanoic acid, 9,10, 13-trihydroxy-11-octadecanoic acid, 9, 13-dihydroxy-12-ethoxy-10-octadecanoic acid, 9-hydroxy-10, 12-octadecanoic acid, 4, 14-dihydroxy-octadecanoic acid, 14-hydroxy-cis-11-eicosenoic acid, transricinoleic acid, fulvic acid, beta-9-hydroxy-10, 12-octadecadienoic acid, 12-hydroxy-9, 15-octadecadienoic acid, 8-methoxy-13-hydroxy-9, 11-octadecanoic acid, 7-oxo-octadecanoic acid, 9-oxo-octadecanoic acid, 12-oxo-octadecanoic acid, 9,10, 13-trihydroxy-octadecanoic acid, 9,10, 13-dihydroxy-octadecanoic acid, 9,10,13, 10-oxo-14-methyl-pentadecanoic acid, or mixtures thereof.

7. The method of claim 1, wherein the composition further comprises 12-oxo-octadecanoic acid.

8. The method of claim 1, wherein the composition comprises 2 to 9 weight percent 12-hydroxystearic acid and/or salts thereof.

9. The method of claim 1, wherein the composition comprises ricinoleic acid.

10. The method of claim 4, wherein the composition comprises ricinoleic acid.

11. The method of claim 1, wherein the hetero-substituted saturated aliphatic acid additive for lightening skin consists of 12-hydroxystearic acid and/or a salt thereof, and the composition further comprises phenoxyethanol.

12. The method of claim 1, wherein the composition comprises niacinamide.

13. The method of claim 1, wherein the skin lightening hetero-substituted saturated aliphatic acid additive comprises from 0.1 to 12 weight percent of the composition.

14. The method of claim 1, wherein the skin lightening hetero-substituted saturated aliphatic acid additive comprises 0.1 to 10 weight percent of the composition.

15. The method of claim 1, wherein the composition is in the form of a liquid, cream, gel, or toner, or is applied via a patch or mask.

16. The method of claim 1, wherein the composition is applied directly to the skin to lighten a spot in need of skin lightening.

17. The method of claim 3, wherein the composition is applied directly to the skin to lighten a spot in need of skin lightening.

18. The method of claim 1, wherein the composition is applied directly onto skin to reduce melanogenesis and the composition comprises resorcinol.

19. The method of claim 1, wherein the composition is applied directly onto skin to reduce melanin production and the composition comprises niacinamide.

20. The method of claim 4, wherein the composition is applied directly to the skin to lighten a spot in need of skin lightening.

21. The method of claim 19, wherein the composition further comprises a sunscreen agent, a preservative, a cellulose derivative, vitamin C, or a mixture thereof.

22. The method of claim 21, wherein the sunscreen agent is selected from titanium dioxide and zinc oxide.

23. The method of claim 1, wherein the skin is skin on the face or on the hands and the composition comprises a thickening agent, octyl methoxycinnamate, or both.

24. The method of claim 4, wherein the skin is skin on the face or on the hands.

25. The method of claim 4, wherein the composition is applied directly onto skin to reduce melanogenesis and comprises resorcinol.

26. The method of claim 4, wherein the composition is a leave-on emulsion, cream, or serum.

27. The method of claim 3, wherein the composition is in the form of a liquid, cream, gel, or toner, or is applied via a patch or mask.

28. The method of claim 3, wherein the composition is a leave-on emulsion or serum.

29. The method of claim 1, wherein the composition further comprises a sunscreen and has a pH of 4.5 to 7.5.

30. The method of claim 1, wherein the composition is a leave-on emulsion or serum.