Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
2002-04-25
2003-05-06
Krass, Frederick (Department: 1614)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S484000, C424S485000, C424S486000, C424S490000, C424S501000, C424S063000
Reexamination Certificate
active
06558682
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to discontinuous films formed from skin care compositions which are preferably electrostatically sprayed. The films are characterized by a particular particle size, particle spacing and coverage value which have been found to provide improved appearance and/or skin feel.
BACKGROUND OF THE INVENTION
A variety of topically-applied skin treatment products, including skin lotions, creams, cosmetic foundations and the like, are known. Such products are generally applied by massaging or rubbing into the skin with the fingers or sponge-type applicator to provide essentially complete coverage of the skin with the product. Typically, about 80% or more of the skin surface is covered by the product, forming an essentially continuous film of product on the skin. While such continuous coverage can be beneficial, in certain applications it can result in undesirable effects. For example, while it is desirable to provide cosmetic foundations having good coverage properties, it has been difficult to achieve good coverage while maintaining a natural look and/or skin feel.
Other methods of applying topical products are also known, including air brush, aerosol spraying, non-aerosol pump spraying, and electrostatic spraying. For example, electrostatic spraying of skin treatment agents is disclosed in U.S. Pat. No. 5,494,674, issued to Barnett et al. on Feb. 27, 1996. Electrostatic spraying of topical materials has been proposed as a means for more efficient consumption and product activity, control over application, ease and cleanliness/hygiene of application, and even coverage.
While a variety of topical compositions have been provided, there is an ongoing need to provide skin care compositions which impart good coverage yet a natural appearance. Furthermore, there is an ongoing need to improve the feel of topically applied compositions, e.g., to reduce the sensations of tightness, stiffness, tackiness and/or dryness which can result from some topical products, particularly long wear or transfer resistant products.
In view of these limitations, after much experimentation it has now been found that substantially uniform and discontinuous films formed from topical compositions comprising particulates and having defined physical properties provide improved appearance. More particularly, films of the present invention have defined particle sizes, particle spacing and coverage values according to the methods herein.
The films exhibit an actual percent skin coverage which is significantly lower than products which are not applied in a discontinuous film, but rather for example are applied using conventional methods of massaging or rubbing into the skin. Surprisingly, the films nonetheless provide good coverage in terms of appearance, e.g., evening skin tone and masking local skin imperfections such as spots, blemishes, circles and the like. Furthermore, since a significantly high percentage of the user's bare skin is integrated into the overall appearance of the product application, the appearance is more natural. The actual percent skin coverage of the films is defined herein in terms of their coverage value.
Further appearance benefits have been surprisingly realized where the film is formed from a topical composition comprising an emulsion having the particulate material dispersed in the continuous external phase and are substantially, preferably essentially not present in the internal phase. When such products are applied to the skin, a “clustering” phenomena of pigments results which makes the apparent particle size smaller than the actual particle size which is applied. Such smaller apparent particle sizes tend to provide improved skin appearance such as a more natural look.
Because of one or more of the aforementioned properties, it is possible to utilize a broader range of shade palettes while maintaining a natural appearance.
In addition to such appearance improvements, the present invention also tends to improve skin feel, e.g., reduce sensations of tightness, dryness, tackiness and/or stiffness, which might otherwise be experienced if the film were continuous. The present invention also increases formulation capability since it becomes possible to use a wider variety of skin care components which may otherwise have the potential to irritate certain individuals. Application of compositions as a discontinuous film according to the present invention tends to reduce any potential for irritation.
SUMMARY OF THE INVENTION
The present invention relates to substantially uniform, discontinuous films of a topical composition having a defined average particle size, particle spacing and coverage values according the methods described herein. The films provide improved skin appearance, e.g., good apparent coverage and a natural look.
The films hereof have an average particle size (diameter) of from about 0.5 to about 150 microns, more preferably from about 1 to about 100 microns, most preferably from about 5 to about 80 microns. Preferred standard deviations for the average particle size are or are less than 1.5 times, more preferably 1.0 times, most preferably 0.7 times, the average particle size.
The films hereof also have an average spacing between particles of at least about 3 microns, more preferably at least about 7 microns, most preferably at least about 10 microns.
The films further have a coverage value of less than about 80%, preferably less than about 70%, more preferably less than about 60%.
The topical compositions from which the films are formed comprise one or more particulate materials dispersed in a carrier which comprises one or more liquid diluents. The liquid diluents may be volatile or nonvolatile, and polar or non-polar.
The composition is preferably electrostatically sprayable, comprising at least one conductive material which is preferably a liquid, more preferably a volatile liquid. The electrostatically sprayable compositions may also comprise one or more insulating materials, at least one of which is preferably liquid and more preferably a volatile liquid. More preferably, the electrostatically sprayable composition comprises an emulsion wherein the insulating material and conductive material are in different phases, even more preferably wherein the insulating material is in the continuous, external phase and the conductive material is in the discontinuous, internal phase.
In a preferred embodiment, the topical composition further comprises one or more materials for imparting transfer or wear resistance, structuring or thickening agents, emulsifiers, co-solubilizers and mixtures thereof.
The films can be formed by topical application of the composition by any suitable method, including silk screening or the like and electrostatic spray techniques, to provide the defined particle size, particle spacing and coverage value. The films are preferably formed by electrostatically spraying the composition onto the skin.
The present invention can be used in a variety of topical applications where deposition of a discontinuous product film would be advantageous, and is particularly well suited to cosmetic foundation applications. For example, compositions of the invention may be designed and utilized to reduce potential for local irritation, to provide more uniform and/or natural-looking application of skin treatment agents or compositions, including pigmented products such as color cosmetics, and/or to improve the feel of extended-wear or transfer resistant products. In particular, extended-wear or transfer resistant products have been found to exhibit improved feel when applied discontinuously in accordance with the present invention. Pigmented products provide sufficient coverage of imperfections, while providing a natural look. Better shade matching of skin and pigmented foundation compositions is also enabled, e.g., because the foundation integrates with the natural skin color, creating a composite shade. The present invention therefore enables broader useful shade palettes.
DETAILED DESCRIPTION OF THE INVENTION
The essentia
Leppla Jeffrey Keith
Prosise Robert Lawrence
Rabe Thomas Elliot
Yen Helen Shu Ying
Clark Karen F.
Kendall Dara M.
Krass Frederick
Ostrup Clinton
Rosnell Tara M.
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