BACKGROUND OF THE INVENTION The cosmetic appearance of fingernails has long been a matter of concern to consumers. Nail polishes and artificial fingernails are among the popular cosmetic treatments applied to the nails (fingernails or toenails, hereinafter collectively called "nails"). However, regular or even occasional use of such products can leave the natural nail yellowed and stained. In addition, coffee, cigarettes, certain medications, and the use of harsh chemicals in the home, may also leave the nail undesirably yellow and uneven in color.

Products are available on the market that coat the nail with a slight purple tint, in the manner of a nail polish, to counteract the yellow coloring of the nail. However, just like nail polish, these products have limited durability, require frequent reapplication, and function only to mask the nail problem, not to correct it. Such products also do not improve the condition of the cuticle.

In addition, home bleaching remedies are also known. These remedies use oxidizing agents such as hydrogen peroxide, in one of two types of compositions. The first of these is a stable acidic composition, in which the bleaching effectiveness of the hydrogen peroxide is curtailed. In a lower pH solution, the functional activity of the hydrogen peroxide is reduced, and the composition does not

"wet out" or disperse as effectively on the nail, limiting contact between the hydrogen peroxide and the stain. Alternatively, higher pH compositions are known. However, lower pH compositions typically require the addition of an activator. This activator must be added immediately prior to use, thus necessitating a two-phase composition.

Accordingly, a need exists for a single phase, shelf-stable nail bleaching product that effectively bleaches and removes nail stains and yellowing.

SUMMARY OF THE INVENTION Against the foregoing background, it is a primary object of the present invention to provide a shelf-stable nail cosmetic composition for removing nail stains and yellowing.

It is a further object of the present invention to provide a nail bleaching cosmetic that is premixed and does not require additional preparation by the user prior to application.

It is another object of the present invention to provide a cosmetic composition that softens and removes dead cuticle skin.

It is yet another object of the present invention to provide a cosmetic composition having the foregoing attributes that is not harmful to the nail or to healthy cuticle tissue.

It is a still further object of the present invention to provide such a cosmetic composition that is buffered against change in pH over time, to enhance stability and long-term effectiveness.

To the accomplishment of the foregoing objects and advantages, the present invention, in brief summary, comprises a nail bleach containing stabilized hydrogen peroxide in an acceptable

carrier. More preferably, the nail bleach also includes a pH adjusting agent to bring the composition to a higher pH. A preferred cosmetic composition for treating nails includes from about 0.01 percent by weight or weight percent to about 10 weight percent stabilized hydrogen peroxide, a pH adjusting agent in an amount sufficient to adjust said cosmetic composition to a pH from about 8.0 to about 8.5, and water. Alternate preferred nail bleach compositions of the present invention include a buffer component.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention provides a nail bleach composition that is premixed, shelf-stable and safe to the nails and healthy cuticle skin. In addition, regular use of the claimed composition softens and removes dead cuticle skin, further improving the appearance of the nails. As discussed herein, shelf- stable cosmetic compositions are those in which the oxidizing agent does not degrade over normal product distribution periods, storage periods and temperature extremes to the point that it is no longer active.

The stable nail bleach compositions of the present invention include stabilized hydrogen peroxide, in a cosmetically acceptable carrier. The carrier preferably is water. More preferably, the carrier is demineralized water.

These compositions are not multi-component systems, but include only a single preformulated component. They require no mixing or activation immediately prior to use. They can be packaged in a standard jar or other dispenser and can be applied directly to the nail and cuticle. Preferably, the composition is used on a regular basis, such as once

daily, until results are achieved. If the nails are continually being stained, due to daily smoking, for example, the product can be applied to the nails indefinitely. In addition, the composition can be safely applied to the nails more than once a day to accelerate the bleaching process.

The stabilized hydrogen peroxide of the present invention is hydrogen peroxide in a stabilized form such that contact with aqueous carriers and extended storage do not result in any significant deactivation of the hydrogen peroxide. The stabilized hydrogen peroxide functions as the bleaching agent in the nail bleach of the present invention. At very low levels, it will have little effect on nail stains, and at high levels it will be irritating or harmful to the nail and surrounding skin. Accordingly, the stabilized hydrogen peroxide is preferably present at about 0.01 to about 10 weight percent of the composition, and more preferably at about 2 to about 5 weight percent of the composition. Most preferably, the stabilized hydrogen peroxide is present at about 3.0 to about 3.5 weight percent.

It has been found that certain stabilized hydrogen peroxides work in the compositions of the present invention, and it is believed that all stabilized hydrogen peroxides will work. The preferred stabilized hydrogen peroxides include stabilized hydrogen peroxides sold by Solvay Interox under the tradenames Cosmetic Grade, PeroxClean and Ultra Cosmetic. The latter two are more preferred, and the latter one is most preferred.

The PeroxClean hydrogen peroxide is preferably 35% active, and has the following properties: Typical Analysis

35% Concentration in water, 35.0-36.0 %W/W Gasometric Stability @ <0.3 100"C, ml 02/min/25 ml H2°2 Active Oxygen, %w/w 16.5 Apparent pH 2.3-2.7 Typical Properties 35% Specific Gravity, 1.13 @20°C, g/ml Density, lb/gal 9.4 Freezing Point OC -33 °F -27 Boiling Point °C 108 F 226 This preferred stabilized hydrogen is an alkaline stabilized hydrogen peroxide.

The Ultra Cosmetic Hydrogen Peroxide is also preferably 35% active. It has the following properties: Typical Analysis 35% Concentration in water, 35.0-36.0 w/w Gasometric Stability @ <0.3 100"C, ml O2/min/25 ml H202 Active Oxygen, % 16.5-17.0 Apparent pH 2.1-3.1 Typical Properties 35% 1 Specific Gravity, @20°C, 1.13 g/ml Density, lb/gal 9.4 Freezing Point °C -33

"F -27 Boiling Point OC 108 "F 226 Again, this preferred stabilized hydrogen peroxide is an alkaline stabilized hydrogen peroxide. This Ultra Cosmetic Hydrogen Peroxide is 35 to 36% hydrogen peroxide, less than 2% potassium stannate, less than 2% tetrapotassium pyrophosphate, less than 2% phosphoric acid, and the balance water.

Other stabilized hydrogen peroxides that can be used in the present invention include in situ stabilized hydrogen peroxide.

For the purposes of the present invention, such proprietary stabilized hydrogen peroxides are distinguished from hydrogen peroxide-containing compositions that are stabilized only due to their low pH. In addition to the preferred stabilized hydrogen peroxide discussed above, a conventional hydrogen peroxide can also be used provided it is in combination with a stabilizer that is formulated into the composition. This combination generates a stabilized hydrogen peroxide that is within the purview of the present invention. Such stabilizers include, for example, phosphoric acid; sodium pyrophosphate; sodium stannate trihydrate; stannate, phosphate, nitrate, magnesium or silicate ions; or amine-substituted organophosponic acids or their alkali metal salts.

The preferred nail bleach of the present invention includes a pH adjusting agent in order to preferably maintain the pH of the composition in the range of about 6 to about 9. More preferable is a basic pH (greater than 7), most preferably about 8.0 to about 8.5. Any cosmetically acceptable pH

adjusting agent or agents can be used in the compositions of the present invention, provided they do not contain contaminants at a level sufficient to decompose the hydrogen peroxide. It is believed that the preferred slight alkalinity of the nail bleach is the primary source of its ability to effectively soften cuticles. The pH adjusting agent also acts to accelerate the bleaching process. The pH adjusting component concentration, as well as water level, can be adjusted to achieve this desired pH range. When sodium hydroxide is used as the pH adjusting agent, the most preferred pH in the range of about 8.0 to about 8.5 has been achieved.

The nail bleach of the present invention may include a buffer to further stabilize the pH of the composition. By further stabilization, it is meant that the buffer will enhance or increase the shelf- life of the nail bleach product. The buffer may be used separate from or in addition to a pH adjusting agent in order to maintain the pH of the composition over time, preferably in the range of about 6 to about 9. As discussed above, the composition is more preferably maintained at a basic pH (greater than 7), and most preferably at a pH about 8.0 to about 8.5.

Any cosmetically acceptable buffer or combination of buffers can be used in the compositions of the present invention, provided they do not contain contaminants at a level sufficient to decompose the hydrogen peroxide.

The buffer is preferably present at about 0.1 weight percent to about 2 weight percent of the composition. The preferred buffer for use in the nail bleach compositions of the present invention is anhydrous disodium phosphate. When anhydrous disodium phosphate is used as the buffer, it is most

preferably present at about 1 weight percent.

Anhydrous disodium phosphate is preferred for use in the nail bleach compositions of the present invention because: 1) it is readily available at a pharmaceutical/food grade thus ensuring that it contains little or no contaminants; 2) the potential for irritation is minimized; 3) one of its pKa values is appropriate for the preferred pH range of the compositions; 4) its solubility profile is compatible with the preferred batch ingredients to minimize cloudiness; and 5) it is a sodium salt, which provides common ion compatibility. Other useful buffers include, but are not limited to, sodium benzoate, sodium borate, dibasic sodium phosphate, dibasic potassium phosphate, potassium citrate, sodium citrate, tetrapotassium pyrophosphate, disodium phosphate and tetrasodium pyrophosphate.

To provide a cosmetically pleasing product, and to aid in delivering the stabilized hydrogen peroxide to the nail and cuticle area, a thickener is preferably added to the nail bleach composition of the present invention. Any cosmetic thickener suitable for use with an aqueous peroxide composition may be used in the present composition. The thickener is preferably present at a range of about 0.1 to about 20 weight percent, with a range of about 1 to about 5 weight percent being more preferred.

Thickeners such as acrylic acid polymers (e.g.

Carbopol), steareth-l0 alkyl ether/acrylate copolymer (preferably Salcare SC90 sold by Allied Colloids Inc., an associative thickener), and a polyoxypropylene/polyoxyethylene block copolymer (which also acts as an anti-irritant) are preferred, alone or in combination. Steareth-lO alkyl ether/acrylate copolymer and the

polyoxypropylene/polyoxyethylene block copolymer are most preferred. The most preferred polyoxypropylene/polyoxyethylene block copolymer is Pluronic F127 (POE(196M)-POP(67M) block polymer) sold by BASF Corporation.

A fragrance may be added to the nail bleach composition, to enhance its appeal and acceptability.

The fragrance is preferably present at up to about 2 weight percent, with a range of about 0.0001 to about 1.0 weight percent being most preferred. Any suitable and compatible cosmetic fragrance may be used. A fragrance is compatible when it works with the system without any deleterious effects.

When certain thickeners are used, the addition of a viscosity stabilizer to the composition may further improve the aesthetics of the finished product. Viscosity stabilizers are useful in the nail bleach compositions of the present invention, to enhance the stability of the composition over time.

The viscosity stabilizers that are preferred for use in the compositions of the present invention are surfactants that can survive in contact with oxidizing agents. The viscosity stabilizers are preferably present at up to about 25 weight percent, with a weight percent of up to about 10 being more preferred. Most preferred viscosity stabilizers include anionic surfactants such as sodium lauryl sulfate (which also acts as a degreaser), and Pluronic F127, a polyoxypropylene/polyoxyethylene block copolymer provided by BASF Corporation (which also acts as an anti-irritant), alone or in combination. Surfactants can also function in compositions of the present invention to reduce the surface tension of the composition, to enhance "wet out" or dispersion of the hydrogen peroxide on the

nail. Accordingly, surfactants can be used in compositions of the present invention that do not contain thickeners. Degreasing or cleansing surfactants that are compatible with peroxides are preferred for use in the compositions of the present invention. The most preferred such surfactant is lauryl sulfate.

Additional ingredients such as vitamins, glycerin, healing and treatment agents may also be added to the nail bleach composition.

Panthenol is a preferred vitamin for use in the present invention. It is preferably present at about 0.01 weight percent.

Glycerin acts to moisturize the nails and cuticles. Glycerin is preferably present at up to about 2 weight percent. More preferably, glycerin is present at about 0.5 weight percent.

The healing agents may include, for example, green tea extract or aloe or a combination thereof.

The treatment agents may include, for example, members of the aldehyde chemical family.

Certain active ingredients such as stabilized hydrogen peroxide and a pH adjusting agent, sodium hydroxide, are provided in solution containing a percentage of active ingredients. For example, the hydrogen peroxide solution of the foregoing preferred embodiment is present at 9.71 weight percent of 35% active solution. Accordingly, stabilized hydrogen peroxide, as the term is used in the appended claims, is present at about 3.4 weight percent (.35 x .0971 0.034)- The following are preferred exemplary nail bleach compositions according to the present invention: Example 1

NAIL BLEACH Wt.

Demineralized water 80.74 Hydrogen peroxide 35%- alkaline stabilized 9.71 Sodium hydroxide solution 50% 0.44 (or q.s. to pH 8-8.5) Disodium phosphate-anhydrous 1.00 Polyoxypropylene/polyoxyethylene block polymer 5.00 Steareth-10 alkyl ether/ acrylate copolymer 2.50 Glycerin 0.50 Panthenol 0.01 Fragrance 0.10 Example 2 NAIL BLEACH Wt.

Deionized water 81.42 Ultra Cosmetic peroxide (35% active) 9.71 Sodium hydroxide (25% active) 0.77 Disodium phosphate-anhydrous 1.00 Steareth-lO alkyl ether/ acrylate copolymer 2.00 Polyoxypropylene/polyoxyethylene block copolymer 5.00 Fragrance 0.10 Example 3 NAIL BLEACH Ultra cosmetic peroxide (35% active) 9.71 Deionized water 82.42 Sodium hydroxide (25% active) 0.77 Steareth-lO alkyl ether/ acrylate copolymer 2.00 Fragrance 0.1 Polyoxypropylene/polyoxyethylene block copolymer 5.00 Other preferred examples according to the present invention include: 1) the product of Example 3 formulated with the added viscosity stabilizer sodium lauryl sulfate (at 1.9 wt% plus 0.1 wt% sodium chloride -- the water level is accordingly decreased by 2.00 wt%); and

2) the product of Example 3 formulated with the added viscosity stabilizer sodium lauryl sulfate (at 1.9 wt% plus 0.1 wt% sodium chloride), but without the viscosity stabilizer polyoxypropylene/polyoxyethylene block copolymer (the water level is accordingly increased by 3.00 weight percent).

While the improved cosmetic appearance of fingernails is a primary object of the present invention, it is evident that stained or yellowed toenails, for example, can also be treated by the claimed compositions and methods. Toenails are also commonly coated with nail polish, and can also be stained by such things as medications or dyes in socks or other footwear.

The invention having been thus described with particular reference to the preferred forms thereof, it will be obvious that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.