Drug – bio-affecting and body treating compositions – Face or body powders for grooming – adorning – or absorbing
Reexamination Certificate
1999-02-03
2002-07-09
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Face or body powders for grooming, adorning, or absorbing
C424S401000
Reexamination Certificate
active
06416751
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cosmetic or dermatological powder, to a process for its manufacture and to its uses, in particular to care for, cleanse, remove make-up from, make up and/or treat the skin, mucous membranes and/or the scalp.
2. Description of the Background
It is known in the cosmetics or dermatological field that, to remedy the defects (greasy feel, difficulty in taking up) of the anhydrous products commonly used, powders can be used which contain a large percentage of oil, these powders thus having the advantage of being comfortable to apply. However, these powders usually contain surfactants, which are potential irritant agents, and are generally rehydrated at the time of use, resulting in handling difficulties.
Moreover, make-up powders are known which have a low oil content and a high filler content and which cannot be used as care products since, in this case, they have the drawback of not being sufficiently comfortable to use because of their low content of oily phase, and of inevitably leaving a visible film on the surface of the skin.
In the field of skincare, EP-A-664,112 describes a powder based on oil, biopolymers and polysaccharides, which is obtained from an oil-in-water (O/W) emulsion and which can be used just as it is or after rehydration into an O/W emulsion. However, such a powder has the drawback of containing biopolymers chosen from proteins of animal or plant origin, which are essential to the constitution of the powder since they constitute its support. Now, the use of proteins of animal origin in cosmetic or dermatological products is avoided. In addition, these proteins does not keep well over time, and certain proteins of plant origin, such as soybean proteins, can prove to be irritant, in particular when they are used in an amount of at least 4%, which is the case in the present document.
Moreover, the powder obtained according to EP-A-664,112 is hygroscopic, which is a drawback when it is desired to use the powder just as it is, since it has a tendency to become damp and consequently exhibits poor conservation characteristics in humid tropical countries.
Moreover, WO-A-95/28849 describes solid compositions which can be used in the food sector, which are prepared by dehydration of aqueous dispersions of starch and of oil, and which can be readily redispersed in water to form stable dispersions without requiring the use of an emulsifier. The process used according to that document consists in subjecting the mixture of starch, oil and aqueous phase to high temperatures and pressures in order to dissolve the starch completely in the aqueous phase. This technique has the drawback of requiring the use of high temperatures during the mixing of the starch, oil and aqueous phase, and these high temperatures can be particularly deleterious when the composition contains oils of plant origin which are readily oxidizable and thus sensitive to high temperatures, or when it is desired to add temperature-sensitive active agents, which is often the case in the cosmetics field. Furthermore, the powder obtained is hygroscopic and thus sensitive to the presence of water, with the same drawbacks as indicated above. In addition, in the examples cited in that document, the starch used is native starch which, besides the drawback of giving hygroscopic compositions, also has the drawback of having poor bacteriological protection.
SUMMARY OF THE INVENTION
The inventors have found, unexpectedly,that the use of modified starch provides an anhydrous cosmetic or dermatological powder which can contain at least one fatty substance and which does not have the drawback, in particular of hygroscopicity, of known powders, and for which preparation does not require complete solubilization of the starch and thus the use of high temperatures and pressures during the mixing of the starch, oil and aqueous phase.
Thus, an object of the present invention is to provide a cosmetic or dermatological powder, which comprises from 5 to 70% by weight of at least one modified starch and from 30 to 95% by weight of an oily phase comprising at least one oil, relative to the total weight of the composition.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
The term “powder” refers to a solid substance divided into very fine, homogeneous particles or grains. The powder may contain less than 2% by weight protein, such as at most 0.001, 0.005, 0.01, 0.05, 0.1, 0.2, 0.5, 1.0, 1.2 or 1.5% by weight. The powder preferably contains no protein.
According to one specific embodiment of the invention, the powder comprises from 5 to 50% of modified starch and from 50 to 95% of an oily phase. These ranges include all specific values and subranges therebetween, including 10, 15, 20, 25, 30, 40, 55, 60, 70, 75, 80, 85 and 90% by weight. The powder according to the invention comprises an oily phase fixed in the modified starch.
This powder in particular has the advantages that it can be applied to any type of skin without leaving a greasy effect, despite the large amount of oil, of being quick and easy to use, of penetrating into the skin without leaving a visible film, of retaining the moisturizing properties of the fatty substances and of not requiring the addition of a liquid such as water since it can be used just as it is. In addition, the desired amount can be taken up easily.
In addition, since this powder can be obtained without an emulsifier and since it keeps well, the addition of emulsifiers and/or of preserving agents can be avoided, and a powder which is much less irritant than the standard care products can thus be obtained. Accordingly, a preferred embodiment of the present invention excludes emulsifier.
Moreover, a cosmetic product presented in this form allows the incorporation of compounds with various physicochemical properties. This product can thus comprise detergents. This makes it possible in particular to cleanse the skin while at the same time moisturizing and nourishing it. Thus, the inventive composition may be a cosmetic or dermatological product having a variety of applications and one which is not specific to one type of skin.
Moreover, compounds known to be sensitive to water and/or to oxidation, such as vitamins (vitamin C., vitamin A or their esters) or enzymes, can be incorporated into the inventive powder. These compounds are preserved for a long time in this medium and therefore do not lose their activity over time.
The powder according to the invention has a particle size (or number-average particle size) which can range in particular from about 0.1 to about 100 &mgr;m, preferably from 0.5 to 50 &mgr;m and more preferably from 1 to 10 &mgr;m. The particle size ranges include all specific values and subranges therebetween, including 0.2, 2, 5, 8, 12, 15, 20, 25, 30, 40, 60, 70, 80, 85, 90 and 95 &mgr;m. The particle size may be measured with the machine “Microtrac×100 & SRA 150” from Leeds-Northrup.
The modified starch used in the composition of the invention can be modified by one or more of the following reactions: pregelatinization, oxidation, crosslinking, or esterification.
More specifically, these reactions can be carried out in the following way:
pregelatinization by bursting the starch granules (for example drying and cooking in a drying drum);
oxidation with strong oxidizing agents leading to the introduction of carboxyl groups into the starch molecule and to the depolymerization of the starch molecule (for example by treating an aqueous starch solution with sodium hypochlorite);
crosslinking with functional agents capable of reacting with the hydroxyl groups of the starch molecules, which will thus be linked together (for example with glyceryl and/or phosphate groups);
esterification in alkaline medium in order to graft functional groups, in particular acetyl, hydroxyethyl, hydroxypropyl, carboxymethyl,
Bordeaux Dominique
Roulier Veronique
Howard S.
L'Oreal
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Page Thurman K.
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