WO1999047115A1

WO1999047115A1 - Skin care compositions

Info

Publication number: WO1999047115A1
Application number: PCT/US1999/005410
Authority: WO
Inventors: Brent William Mason
Original assignee: The Procter & Gamble Company
Priority date: 1998-03-16
Filing date: 1999-03-12
Publication date: 1999-09-23
Also published as: AU3082599A

Abstract

The present invention relates to skin care compositions comprising vitamin B3 compound and an improved carrier system.

Description

SKIN CARE COMPOSITIONS

FIELD OF THE INVENTION The present invention relates to skin care compositions comprising vitamin

B3 compound and an improved carrier system.

BACKGROUND OF THE INVENTION

Niacin, also known as vitamin B₃, is the common name for nicotinic acid. The physiologically active form of niacin is niacinamide. Niacin and niacinamide (nicotinic acid amide) function in the body as components of two coenzymes: nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). Until recently, these vitamin B₃ compounds were used exclusively to treat niacin deficiency and pellegra.

Today, however, vitamin B₃ compounds have also found use in the area of skin care actives. British Patent 1,370,236 describes compositions for skin lightening containing 0.5% to 10% niacin. Similarly, U.S. Patent 4,096,240 discloses the use of

0.1% to 10% niacinamide for skin lightening. It is postulated that these vitamin B₃ compounds act by retarding melanin dispersion or distribution into the epidermis.

A problem with using vitamin B₃ compounds as skin care actives, however, concerns the stability of such compounds in skin care formulations. For instance, skin care compositions containing high concentrations of a non-aqueous phase in addition to vitamin B₃ compounds tend to leave a visible white residue on the skin upon application. This residue apparently results from a "salting out" of the vitamin B₃ compound. The present inventor has discovered that incorporation of a neutralizing agent along with the vitamin B compound in compositions containing high amounts of a non-aqueous phase provide compositions having improved aesthetics and reduced visible white residue after application.

It is, therefore, an object of the present invention to provide high non- aqueous phase compositions containing vitamin B₃ compounds and a neutralizing agent. 2

It is also an object of the present invention to provide high non-aqueous phase compositions containing vitamin B₃ compounds having reduced visible residue.

These and other objects will become readily apparent from the detailed description which follows. SUMMARY OF THE INVENTION

The present invention relates to skin care compositions having improved stability, comprising:

A) a safe and effective amount of a vitamin B₃ compound as a skin care active; and B) a multiphase carrier component which comprises the balance of the composition and which further comprises: i) a non-aqueous phase which comprises at least about 8% by weight of the composition; and ii) an aqueous phase, wherein the aqueous phase contains a neutralizing agent of type and amount that is sufficient to maintain a composition at pH of from about 6 to about 10. The present invention further relates to methods of using the skin care compositions.

DETAILED DESCRIPTION OF THE INVENTION The skin care compositions of the present invention can comprise, consist of, or consist essentially of the essential elements and limitations of the invention described herein, as well any of the additional or optional ingredients, components, or limitations described herein.

All percentages, parts and ratios are based upon the total weight of the skin care compositions of the present invention, unless otherwise specified. All such weights as they pertain to listed ingredients are based on the active level and, therefore, do not include carriers or by-products that may be included in commercially available materials, unless otherwise specified. Vitamin B3 component The compositions of the present invention comprise a safe and effective amount of a natural or synthetic vitamin B3 compound. The compositions of the 3

present invention preferably comprise from above 0.1% to about 50%, more preferably from about 1% to about 30%, even more preferably from about 5% to about 20% of the vitamin B3 compound.

As used herein, "vitamin B3 compound" means a compound having the formula:

Or wherein R is - CO H2 (i.e., niacinamide), - COOH (i.e., nicotinic acid) or - CH2OH

(i.e., nicotinyl alcohol); derivatives thereof; and salts of any of the foregoing.

Exemplary derivatives of the foregoing vitamin B3 compounds include nicotinic acid esters, including non-vasodilating esters of nicotinic acid, nicotinyl amino acids, nicotinyl alcohol esters of carboxylic acids, nicotinic acid N-oxide and niacinamide N-oxide.

Suitable esters of nicotinic acid include nicotinic acid esters of C1-C22, preferably Cj-C^, more preferably Cj-Cg alcohols. The alcohols are suitably straight-chain or branched chain, cyclic or acyclic, saturated or unsaturated (including aromatic), and substituted or unsubstituted. The esters are preferably non- rubifacient. As used herein, "non-rubifacient" means that the ester does not commonly yield a visible flushing response after application to the skin in the subject compositions (the majority of the general population would not experience a visible flushing response, although such compounds may cause vasodilation not visible to the naked eye). Alternatively, a nicotinic acid material which is rubifacient at higher doses could be used at a lower dose to reduce the rubifacient effect. Non-rubifacient esters of nicotinic acid include tocopherol nicotinate and inositol hexanicotinate; tocopherol nicotinate is preferred. Other derivatives of the vitamin B3 compound are derivatives of niacinamide resulting from substitution of one or more of the amide group hydrogens. Nonlimiting examples of derivatives of niacinamide useful herein include nicotinyl amino acids, derived, for example, from the reaction of an activated nicotinic acid compound (e.g., nicotinic acid azide or nicotinyl chloride) with an amino acid, and nicotinyl alcohol esters of organic carboxylic acids (e.g., Cl - C18). Specific examples of such derivatives include nicotinuric acid and nicotinyl hydroxamic acid, which have the following chemical structures: nicotinuric acid: o o

II II NH— CHi— COH

nicotinyl hydroxamic acid:

Exemplary nicotinyl alcohol esters include nicotinyl alcohol esters of the carboxylic acids salicylic acid, acetic acid, glycolic acid, palmitic acid and the like.

Other non-limiting examples of vitamin B3 compounds useful herein are 2- chloronicotinamide, 6-aminonicotinamide, 6-methylnicotinamide, n-methyl- nicotinamide, n,n-diethylnicotinamide, n-(hydroxymethyl)-nicotinamide, quinolinic acid imide, nicotinanilide, n-benzylnicotinamide, n-ethylnicotinamide, nifenazone, nicotinaldehyde, isonicotinic acid, methyl isonicotinic acid, thionicotinamide, nialamide, l-(3-pyridylmethyl) urea, 2-mercaptonicotinic acid, nicomol, and niaprazine.

Examples of the above vitamin B3 compounds are well known in the art and are commercially available from a number of sources, e.g., the Sigma Chemical Company (St. Louis, MO); ICN Biomedicals, Inc. (Irvin, CA) and Aldrich Chemical Company (Milwaukee, WI).

One or more vitamin B3 compounds may be used herein. Preferred vitamin

B3 compounds are niacinamide and tocopherol nicotinate. Niacinamide is more preferred. 5

When used, salts, derivatives, and salt derivatives of niacinamide are preferably those having substantially the same efficacy as niacinamide in the methods of regulating skin condition described herein.

Salts of the vitamin B3 compound are also useful herein. Nonlimiting examples of salts of the vitamin B3 compound useful herein include organic or inorganic salts, such as inorganic salts with anionic inorganic species (e.g., chloride, bromide, iodide, carbonate, preferably chloride), and organic carboxylic acid salts (including mono-, di- and tri- Cl - C18 carboxylic acid salts, e.g., acetate, salicylate, glycolate, lactate, malate, citrate, preferably monocarboxylic acid salts such as acetate). These and other salts of the vitamin B3 compound can be readily prepared by the skilled artisan, for example, as described by W. Wenner, "The Reaction of L- Ascorbic and D-Isoascorbic Acid with Nicotinic Acid and Its Amide", J. Organic Chemistry, VOL. 14, 22-26 (1949), which is incorporated herein by reference. Wenner describes the synthesis of the ascorbic acid salt of niacinamide. In a preferred embodiment, the ring nitrogen of the vitamin B3 compound is substantially chemically free (e.g., unbound and/or unhindered), or after delivery to the skin becomes substantially chemically free ("chemically free" is hereinafter alternatively referred to as "uncomplexed"). More preferably, the vitamin B3 compound is essentially uncomplexed. Therefore, if the composition contains the vitamin B3 compound in a salt or otherwise complexed form, such complex is preferably substantially reversible, more preferably essentially reversible, upon delivery of the composition to the skin. For example, such complex should be substantially reversible at a pH of from about 5.0 to about 6.0. Such reversibility can be readily determined by one having ordinary skill in the art. More preferably the vitamin B3 compound is substantially uncomplexed in the composition prior to delivery to the skin. Exemplary approaches to minimizing or preventing the formation of undesirable complexes include omission of materials which form substantially irreversible or other complexes with the vitamin B3 compound, pH adjustment, ionic strength adjustment, the use of surfactants, and formulating wherein the vitamin B3 compound and materials which complex 6

therewith are in different phases. Such approaches are well within the level of ordinary skill in the art.

Thus, in a preferred embodiment, the vitamin B3 compound contains a limited amount of the salt form and is more preferably substantially free of salts of a vitamin B3 compound. Preferably the vitamin B3 compound contains less than about 50% of such salt, and is more preferably essentially free of the salt form. The vitamin B3 compound in the compositions hereof having a pH of from about 4 to about 7 typically contain less than about 50% of the salt form.

The vitamin B3 compound may be included as the substantially pure material, or as an extract obtained by suitable physical and/or chemical isolation from natural (e.g., plant) sources. The vitamin B3 compound is preferably substantially pure, more preferably essentially pure.

Vitamin B3 compounds which exist in crystalline form are particularly preferred for use herein. Carrier System

The compositions of the present invention comprise an improved carrier system. The improved carrier is a dermatologically acceptable carrier. The phrase "dermatologically-acceptable carrier", as used herein, means that the carrier is suitable for topical application to the skin, has good aesthetic properties, is compatible with the actives of the present invention and any other components, and will not cause any untoward safety or toxicity concerns.

As alluded to above, compositions containing vitamin B₃ compounds and high concentrations of a non-aqueous phase tend to leave a visible white residue on the skin upon application. This may be the result of recrystallization of the vitamin B₃ compound due to the increased concentration of the non-aqueous phase in these formulas. The term "non-aqueous phase" or "oil phase," as used herein, means that only an oil or oil like substance is present or, indeed, that the phase contains any hydrocarbon material commonly known by the term "oil." The term "water phase" or "aqueous phase," as used herein, means the water portion of the carrier. It should be understood, however, that the term "aqueous phase" should not be taken to mean that water is present to the exclusion of all other ingredients in that phase. The term 7

"high non-aqueous phase," as used herein, means a non-aqueous phase concentration in the carrier of at least about 8%, preferably from about 8% to about 30%, more preferably from about 15% to about 20%, by weight of the total composition. Without being limited by theory, it is believed that the improved carrier system of the present invention facilitates the dissolution of vitamin B₃ compounds in the non- aqueous phase of the compositions and, additionally, retards the precipitation of the vitamin B₃ compounds in such compositions over time. The ratio of the non-aqueous phase to the aqueous phase is preferably from about 92:8 to about 70:30, preferably from about 90:10 to about 75:25, and more preferably from about 85: 15 to about 80:20.

An essential ingredient of the improved carrier system is a neutralizing agent sufficient to neutralize the present compositions to a pH of from about 6 to about 10, preferably from about 7 to about 10, and more preferably from about 8 to about 10. The neutralizing agent of the present invention is preferably a weak base having a pKa from about 6 to about 9. Examples of suitable neutralizing agents include alkanolamines such as monoethanolamine, diethanolamine and triethanolamine; alkylamines such as triethylamine, diethylamine, monoethylamine, diisopropylamine, trimethylamine and diisobutylamine, alkylalkanolamines such as dimethylaminoethanol; alicyclic amines such as cyclohexylamine; alkali metal hydroxides such as sodium hydroxide and potassium hydroxide; and ammonia. Mixtures of the above neutralizing agents may also be used. Preferred neutralizing agents are alkanolamines.

The improved carrier system of the present invention may optionally contain a thickener. Examples of suitable thickeners include naturally-occurring polymeric materials such as sodium alginate, xanthan gum, quince seed extract, tragacanth gum, starch and the like, semi-synthetic polymeric materials such as cellulose ethers (e.g. hydroxyethyl cellulose, methyl cellulose, carboxymethyl cellulose, hydroxy propylmethyl cellulose), polyvinylpyrrolidone, polyvinylalcohol, guar gum, hydroxypropyl guar gum, , soluble starch, cationic celluloses, cationic guars and the like and synthetic polymeric materials such as carboxyvinyl polymers, polyvinylpyrrolidone, polyvinyl alcohol polyacrylic acid polymers, polymethacrylic 8

acid polymers, polyvinyl acetate polymers, polyvinyl chloride polymers, polyvinylidene chloride polymers and the like. Inorganic thickeners may also be used such as aluminium silicates, such as, for example, bentonites, or a mixture of polyethylene glycol and polyethylene glycol stearate or distearate. Preferred thickeners are those having a high salt tolerance. The term "high salt tolerance" as used herein means that the thickener maintains its function in the presence of aqueous salt solutions having a salt concentration of at least 0.5%. Particularly preferred for use herein are hydroxyethyl cellulose. The thickener is preferably present at a concentration of from about 0.1 to about 2.0%, preferably from about 0.1 to about 1.0%, and more preferably from about 0.1 to about 0.4%. Mixtures above the above polymers may also be used.

Humectants may also be incorporated into the improved carrier system. Suitable humectants include hexylene glycol, PEG-7 glyceryl cocoate, propylene glycol or sorbitol, sodium pyrrolidonecarboxylic acid, glycerin (glycerol), polyethylene glycol wax, D-panthenol, hyaluronic acid, glucosides (e.g., Glucam E10 and E20 available from Amerchol Corporation), lactamide monoethanolamine, and acetamide monoethanolamine and mixtures thereof . Preferred for use herein is glycerin. The humectant is preferably present at a concentration of less than about 10%, preferably from about 2% to about 7%, and more preferably from about 3% to about 5%. Mixtures of the above humectants may also be used.

The carrier can be in a wide variety of forms. For example, emulsion carriers, including, but not limited to, oil-in-water, water-in-oil, water-in-oil-in-water, and oil- in-water-in-silicone emulsions, are useful herein. These emulsions can cover a broad range of viscosities, e.g, from about 100 cps to about 200,000 cps. These emulsions can also be delivered in the form of sprays using either mechanical pump containers or pressurized aerosol containers using conventional propellants. These carriers can also be delivered in the form of a mousse. Other suitable topical carriers include anhydrous liquid solvents such as oils, alcohols, and silicones (e.g., mineral oil, ethanol, isopropanol, dimethicone, cyclomethicone, and the like); aqueous-based single phase liquid solvents (e.g., hydro-alcoholic solvent systems); and thickened versions of these anhydrous and aqueous-based single phase solvents (e.g., where the viscosity of 9

the solvent has been increased to form a solid or semi-solid by the addition of appropriate gums, resins, waxes, polymers, salts, and the like). Examples of topical carrier systems useful in the present invention are described in the following four references all of which are incorporated herein by reference in their entirety: "Sun Products Formulary" Cosmetics & Toiletries, vol. 105, pp. 122-139 (December 1990); "Sun Products Formulary", Cosmetics & Toiletries, vol. 102, pp. 117-136 (March 1987); U.S. Patent No. 4,960,764 to Figueroa et al., issued October 2, 1990; and U.S. Patent No. 4,254,105 to Fukuda et al., issued March 3, 1981.

The carriers of the skin care compositions can comprise from about 50% to about 99% by weight of the compositions of the present invention, preferably from about 75% to about 99%, and most preferably from about 85% to about 95%.

The improved carriers can further include hydro-alcoholic systems as well as oil-in-water emulsions. When the carrier contains a hydro-alcoholic system, the carrier can comprise from about 0% to about 99% of ethanol, isopropanol, or mixtures thereof, and from about 1% to about 99% of water. More preferred is a carrier comprising from about 5% to about 60% of ethanol, isopropanol, or mixtures thereof, and from about 40% to about 95% of water. Especially preferred is a carrier comprising from about 20% to about 50% of ethanol, isopropanol, or mixtures thereof, and from about 50% to about 80% of water. When the carrier is an oil-in- water emulsion, the carrier can include any of the common excipient ingredients for preparing these emulsions. A more detailed discussion of suitable carriers is fount in U.S. Patent 5,605,894 to Blank et al., and in PCT application WO 97/39733, published October 30, 1997, to Oblong et al., both herein incorporated by reference in their entirety. OPTIONAL COMPONENTS

The compositions of the present invention may optionally comprise additional skin actives. Non-limiting examples of such skin actives include hydroxy acids such as salicylic acid and glycolic acid; keto acids such as pyruvic acid; desquamatory agents such as zwitterionic surfactants; sunscreens such as 2-ethylhexyl-p- methoxycinnamate, 4,4'-t-butyl methoxydibenzoyl-methane, octocrylene, phenyl benzimidazole sulfonic acid; sun-blocks such as zinc oxide and titanium dioxide; anti- 10

inflammatory agents; corticosteroids such as hydrocortisone, methylprednisolone, dexamethasone, triamcinolone acetonide, and desoxametasone; anesthetics such as benzocaine, dyclonine, lidocaine and tetracaine; antipruitics such as camphor, menthol, oatmeal (colloidal), pramoxine, benzyl alcohol, phenol and resorcinal; anti- oxidants/radical scavengers such as tocopherol and esters thereof; chelators, especially iron chelators; retinoids such as retinol, retinyl palmitate, retinyl acetate, retinyl propionate, and retinal; N-acetyl-L-cysteine and derivatives thereof; benzofuran derivatives; slimming agents such as caffeine or theophylline; and skin protectants. Mixtures of any of the above mentioned skin actives may also be used. A more detailed description of these actives is found in U.S. Patent 5,605,894 to Blank et al. (previously incorporated by reference). Preferred skin actives include hydroxy acids such as salicylic acid, sunscreen, sunblock, antioxidants and mixtures thereof.

Other conventional skin care product additives may also be included in the compositions of the present invention. For example, urea, guanidine, glycerol, petrolatum, mineral oil, sugar esters and polyesters, polyolefins, methyl isostearate, ethyl isostearate, cetyl ricinoleate, isononyl isononanoate, isohexadecane, lanolin, lanolin esters, cholesterol, fatty acid amides, ceramides, pyrrolidone carboxylic acid/salt (PC A), trimethyl glycine (betaine), tranexamic acid, amino acids (e.g., serine, alanine), panthenol and its derivatives, collagen, hyaluronic acid, elastin, hydrolysates, primrose oil, jojoba oil, epidermal growth factor, soybean saponins, mucopolysaccharides, and mixtures thereof may be used. Other suitable additives or skin actives are discussed in further detail in PCT application WO 97/39733, published October 30, 1997, to Oblong et al., herein incorporated by reference in its entirety. 11

Preparation of Skin Care Compositions

The compositions of the present invention are generally prepared by conventional methods such as are known in the art of making topical compositions. Such methods typically involve mixing of the ingredients in one or more steps to a relatively uniform state, with or without heating, cooling, application of vacuum, and the like. Non-limiting examples of the product form can be a gel, emulsion, lotion, cream, ointment, solution, liquid, etc.

Methods of Treating Skin Conditions The compositions of the present invention are useful for treating or preventing a variety of skin conditions, especially those associated with dermis and epidermis of mammalian skin. The methods disclosed in the present invention involve topically applying to the skin a safe and effective amount of the skin care composition of the present invention. The amount of the composition which is applied, the frequency of application and the period of use will vary widely depending upon the level of vitamin B3 compound and/or other components of a given composition and the level of treatment desired.

The skin care compositions of the present invention can be chronically applied to the skin. By "chronic topical application" is meant continued topical application of the composition over an extended period during the subject's lifetime, preferably for a period of at least about one week, more preferably for a period of at least about two weeks, even more preferably for a period of at least one month, even more preferably for at least about three months, even more preferably for at least about six months, and more preferably still for at least about one year. While benefits are obtainable after various maximum periods of use (e.g., five, ten or twenty years), it is preferred that chronic application continue throughout the subject's lifetime to maintain and/or increase the benefits achieved. Typically applications would be on the order of one to four times per day over such extended periods, however application rates can be more than four times per day, especially on areas particularly-prone to dry skin such as the hands and legs. 12

A wide range of quantities of the compositions of the present invention can be employed to provide a skin appearance and/or feel benefit. Quantities of the present compositions which are typically applied per application are, in mg composition/cm^ skin, from about 0.1 mg/cm^ to about 10 mg/cm^. A particularly useful application amount is about 2 mg/cm^.

The method of treating the various skin conditions is preferably practiced by applying a composition in the form of a skin emulsion, lotion, cream, gel, solution, cosmetic, or the like which is intended to be left on the skin for some esthetic, prophylactic, therapeutic or other benefit (i.e., a "leave-on" composition). After applying the composition to the skin, it is preferably left on the skin for a period of at least about 15 minutes, more preferably at least about 30 minutes, even more preferably at least about 1 hour, most preferably for at least several hours, e.g., up to about 12 hours.

Another approach to ensure a continuous exposure of the skin to at least a minimum level of vitamin B₃ compound is to apply the compound by use of a patch. Such an approach is particularly useful for problem skin areas needing more intensive treatment. The patch can be occlusive, semi-occlusive or non-occlusive. The vitamin B₃ compound composition can be contained within the patch or be applied to the skin prior to application of the patch. The patch can also include additional actives such as chemical initiators for exothermic reactions such as those described in PCT application WO 9701313 to Burkett et al. Preferably the patch is applied at night as a form of night therapy.

EXAMPLES The following examples further describe and demonstrate embodiments within the scope of the present invention. The examples are given solely for the purpose of illustration and are not to be construed as limitations of the present invention, as many variations thereof are possible without departing from the spirit and scope of the invention. Example 1 13

The following is an example of a skin cream (oil in water) incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each column using conventional technology and then applying to the skin from about from about 0.5 g to about 50g.

Ingredient (CTFA Name) % w/w

DRO Water 71.479

Disodium EDTA 0.130

Glycerin 3.000

Methyl Paraben 0.250

Benzyl Alcohol 0.500

Citric Acid 0.190

Triethanolamine 1.960

Niacinamide 10.000

PPG- 15 Stearyl Ether 5.420 (Arlamol E, ICI Americas)

Propyl Paraben 0.100

Stearyl Alcohol 2.028

Cetyl Alcohol 0.559

Behenyl Alcohol 0.221

Steareth-21 (Brij 721, ICI 0.366 Americas)

Steareth-2 (Brij 72, ICI 1.097 Americas)

Distearyldimonium chloride 0.950 (Varisoft TA-100, Sherex)

Silicone fluid 0.750

(Dow Corning DC Q2-1401; cyclomethicone/dimethiconol - 50/50 blend)

Dimethicone 10 cst (Dow 1.000 Corning DC 200/10 cst Fluid

)

Example II

The following is an example of a skin cream (oil in water) incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each column using conventional technology and then applying to the skin from about from about 0.5 g to about 50g. 14

Ingredient (CTFA Name) % w/w

DRO Water 73.960

Disodium EDTA 0.150

Modified Hydroxyethyl 0.150 cellulose (Polysurf 67,

Aqualon)

Glycerin 5.000

Methyl Paraben 0.250

Benzyl Alcohol 0.500

NaOH, 50% Solution 0.040

Niacinamide 5.000

SEFA Cottonate (Sucrose 1.000 ester of fatty acid, Procter and

Gamble)

Mineral Oil 2.000

Cetyl Ricinoleate (Naturechem 3.000 CR, CASCHEM)

Myristyl Myristate 1.500

Caprylic/Capric Triglyceride 1.500 (Myritol 318, Henkel)

Propyl Paraben 0.100

Stearyl Alcohol 0.500

Cetyl Alcohol 0.500

Behenyl Alcohol 0.500

PEG-5 Glyceryl Stearate 1.050 (Arlatone 938, ICI Americas)

Steareth-2 (Brij 72) 1.050

Distearyldimonium chloride 0.250 (Varisoft TA-100)

Silicone fluid (Dow Corning 2.000

DC 2-1068)

Example in

The following is an example of a skin cream (water in oil) incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each column using conventional technology and then applying to the skin from about from about 0.5 g to about 50g.

Ingredient (CTFA Name) % w/w

DRO Water 61.800

Glycerin 7.0000 15

DMDM Hydantoin (and) 0.1000 Iodopropynyl Butylcarbamate (Glydant Plus, Lonza Inc.)

Niacinamide 10.0000

Disodium EDTA 0.1000

Polypropylene glycol- 15 5.0000 stearyl ether (Arlamol E)

Mineral Oil 5.0000

SEFA Cottonate (Sucrose 2.0000 ester of fatty acid, Procter and Gamble)

Isohexadecane (Permethyl 3.0000 101 A, Presperse)

PEG-30 4.0000

Dipolyhydroxystearate (Arlacel P135, ICI)

Petrolatum 2.0000

Example IV

Ingredient (CTFA Name) % w/w

DRO Water 71.340

Glycerin 5.0000

Disodium EDTA 0.1000

Niacinamide 10.0000

Citric Acid 0.2000

Sorbitan monostearate (and) 1.0000 Sucrococoate (Arlatone 2121, ICI Americas Inc.)

Isohexadecane (Permethyl 3.0000 101 A, Presperse)

SEFA Cottonate (Sucrose 0.6700 ester of fatty acid, Procter and Gamble)

Cetyl Alcohol 0.7200 16

Stearic Acid 0.1000

PEG- 100 Stearate (Myrj 59, 0.1000 ICI Americas Inc.)

Stearyl Alcohol 0.4800

Isopropyl Isostearate 1.3300

Polyacryiamide (and) C13-14 2.5000 Isoparaffin (and) Laureth7 (Sepigel 305, Seppic Corp.)

Triethanolamine 1.3600

Silicone fluid (Dow Corning 2.0000

556)

17

Example V

Ingredient (CTFA Name) % w/w

DRO Water 62.370

Glycerin 5.0000

Carbomer (Carbopol 1382, 0.2500 B.F. Goodrich)

Disodium EDTA 0.1000

Niacinamide 10.0000

Citric Acid 0.2000

Sorbitan monostearate (and) 5.5000 Sucrococoate (Arlatone 2121, ICI Americas Inc.)

Isohexadecane (Permethyl 3.0000 101 A, Presperse)

SEFA Cottonate (Sucrose 0.6700 ester of fatty acid, Procter and Gamble)

Cetyl Alcohol 0.7200

Stearyl Alcohol 0.4800

Silicone fluid (Dow Corning 5.0000 556)

Sorbitan Monostearate 1.0000

Petrolatum 2.0000

Isopropyl Isostearate 1.3300

Triethanolamine 2.2800

Example VI The following is an example of a skin cream (water in oil) incorporating the compositions of the present invention. The compositions are formed by combining and mixing the ingredients of each column using conventional technology and then applying to the skin from about from about 0.5 g to about 50g. 18

Ingredient (CTFA Name) % w/w

DRO Water 61.100

Methylparaben 0.200

Benzyl Alcohol 0.300

Alcohol, SDA40 3.000

Disodium EDTA 0.500

Niacinamide 2.000

Hexylene Glycol 2.000

Glycerin 10.000

Triethanolamine 0.050

Silicone fluid (Dow Corning 12.500 345 Fluid)

Silicone fluid (Goldschmidt 2.500 Abil WE-09)

Silicone Fluid (Dow Corning 2.500 Q2-3225C)

Petrolatum 1.500

SEFA Cottonate (Sucrose 1.000 ester of fatty acid, Procter and Gamble)

Butylated hydroxytoluene 0.100

Retinol 0.750

Example Vπ

Ingredient (CTFA Name) % w/w

DRO Water 71.619

Butylene Glycol 0.2500

Sodium Hydroxide Pellets 0.1800

Niacinamide 5.0000

Isopropyl Palmitate 0.6000

Butylated hydroxytoluene 0.0010

Carbomer (Carbopol 954, 0.4000

B.F. Goodrich) 19

Disodium EDTA 0.1000

Glycerin 10.0000

Isopropyl Palmitate 0.6250

Dimethicone (Dow Corning 0.6250 DC200/350 cst)

Silicone fluid (Dow Corning 1.8750 3225C)

Titanium Dioxide 0.7500

Cetyl Palmitate 1.5000

Cetyl Alcohol 2.2500

Stearic Acid 0.3125

PEG-100 Stearate (Myrj 59, 0.3125 ICI Americas Inc.)

Stearyl Alcohol 1.5000

Dimethicone Copolyol (DC 2.0000

2501 Wax, Dow Corning)

Claims

WHAT IS CLAIMED IS:

1. A skin care composition of improved stability, which composition comprises:

A) a safe and effective amount of a vitamin B₃ compound as a skin care active; and

B) a multiphase carrier component which comprises the balance of the composition and which further comprises: i) a non-aqueous phase which comprises at least 8% by weight of the composition; and ii) an aqueous phase, wherein the aqueous phase contains a neutralizing agent of type and amount that is sufficient to maintain a composition at pH of from 6 to 10.

2. A composition according to Claim 1, wherein the neutralizing agent is an alkanolamine.

3. A composition according to any one of the preceding Claims, wherein the aqueous phase is present to the extent that the ratio of the non-aqueous phase to the aqueous phase ranges of from 92:8 to 70:30.

4. A composition according to any one of the preceding Claims, wherein the carrier further comprises a thickener.

5. A composition according to any one of the preceding Claims, further comprising a humectant.

6. A composition according to any one of the preceding Claims, wherein the concentration of the humectant is less than 10%.

7. A composition according to any one of the preceding Claims, wherein said vitamin B3 compound is selected from niacinamide, derivatives of niacinamide, non-vasodilating esters of nicotinic acid, and mixtures thereof.

8. A composition according to any one of the preceding Claims, wherein said vitamin B3 compound is selected from niacinamide, tocopherol nicotinate, and mixtures thereof.

9. A skin care composition of improved stability, which composition comprises:

B) a carrier component which is in the form of an oil-in-water or water- in-oil emulsion, which comprises the bulk of the composition, and which further comprises: i) an oil phase that constitutes from 8% to 30% by weight of the composition; and ii) a water phase present to the extent that the ratio of oil phase to water phase ranges from 90:10 to 75:25 and which contains a neutralizing agent of type and amount which is sufficient to maintain a composition pH of from 8 to 10.