Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1999-04-14
2003-09-02
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S063000, C424S059000, C424S064000, C514S938000, C514S941000
Reexamination Certificate
active
06613338
ABSTRACT:
The present invention relates to cosmetic sticks which are characterized by a high water content and which, as advantageous embodiments, can be W/O emulsions. In particular, the present invention relates to lipsticks, preferably lipcare sticks, but also decorative lipsticks, and also stick formulations which are suitable, for example, for use against acne. As other advantageous embodiments, the present invention relates to sunscreen sticks, eyeshadow sticks and similar products.
From a technical viewpoint, most stick formulations are anhydrous fatty mixtures of solid or semisolid waxes and liquid oils, the ultrapure paraffin oils and waxes forming the lipstick base. Hydrous preparations are also known, which are sometimes also in the form of W/O emulsions.
The ideal profile of requirements includes smooth application of cosmetic or pharmaceutical sticks without substantial friction. Moreover, such a formulation must also satisfy the requirements that the stick in question must be resistant to breaking and to temperature and the formulation must not lose oil.
A lipstick in particular, even when pressed lightly, should leave a non-greasy, dull or sticky, but nevertheless highly adherent lipid film on the lips. This lipid film should make the lips smooth and soft.
If cosmetic or pharmaceutical sticks are to comprise certain active ingredients, it is conceivable that the other constituents are incompatible with the active ingredients. This is frequently the case particularly when it is intended that the cosmetic sticks be used as sunscreen sticks, and, in particular, water-soluble light protection filters are to be present in relatively large amounts in the stick, or when, in the preparation of an antiacne stick, water-soluble antiacne active ingredients are to be incorporated in amounts known to the person skilled in the art.
For reasons of compatibility, it is always preferable, even when using substances which are acceptable per se, to keep the corresponding use concentrations of such active ingredients as low as possible.
An object of the present invention was thus to develop preparations which are suitable as bases for cosmetic light protection filters, physical light protection filters, antiacne active ingredients and vitamins, and which do not have the disadvantages of the prior art. Furthermore, it was also an object of the invention to develop cosmetic bases which are characterized by good skin compatibility.
Customary prior art bases for stick preparations are, for example, liquid oils (e.g. paraffin oils, castor oil, isopropyl myristate), semisolid constituents (e.g. vaseline, lanolin), solid constituents (e.g. beeswax, ceresin and microcrystalline waxes or ozokerite) and high-melting waxes (e.g. carnauba wax, candelilla wax).
Prior art lipsticks containing paraffins and beeswax are described in “Kosmetik, Entwicklung Herstellung und Anwendung kosmetischer Mittel” [Cosmetics, development, preparation and use of cosmetic compositions], p. 105, editor W. Umbach, Georg Thieme Verlag, Stuttgart-New York, 1988.
However, the prior art has a number of disadvantages. These include the fact that water-soluble active ingredients are frequently insufficiently fat-soluble to be incorporated to a significant extent into the cosmetic bases. On the other hand, a certain water content would indeed be desired to increase the compatibility of the cosmetic stick with the human skin. In addition, sticks with very high water contents cannot be prepared in accordance with the prior art because the water is incompatible with the hydrophobic oil/wax/emulsifer matrix.
For an antiacne stick, for example, it would, however, be particularly advantageous if the proportion of fat-soluble constituents were as low as possible.
The skin of the lips has only a very thin horny layer. There are no sweat glands on the lips, and only few sebaceous glands. The skin of the lips is therefore virtually free from lipids and is prone to drying out, particularly in cold and dry weather. It is possible for small cracks to form in the skin, and the susceptibility of the lips to chemical, physical and microbial factors (e.g. foods, sunlight, Herpes simplex viruses) increases.
To prevent this from happening is the purpose of lipcare sticks. These products usually contain a high proportion of waxes and fatty components which form a covering layer over the lips following application.
In the preparations for lipcare sticks, it is possible to additionally incorporate active ingredients which are required for lipcare or for lip protection e.g. vitamins, moisturizers, light protection agents, covering pigments etc.
The dermis of the lips is provided with papillae which are well supplied with blood and extend up to just below the surface of the lips. This is why the lips are red and distinct with regard to colour from the remaining facial skin to a greater or lesser extent depending on the skin colour of the person in question. A stylistic element of decorative cosmetics is to match the colour of the lips to the type of person using suitable cosmetics.
Products of this type are decorative lipsticks into which a very wide range of colour pigments can be incorporated. These sticks, too, contain high proportions of waxes and fatty components which form a covering lipid layer over the lips following application.
However, the purpose of this layer is not primarily to protect the skin of the lips from drying out. The lipid layer serves in this case as a base, which adheres to the lips, for the incorporated pigment materials; the pigments themselves cannot be applied to the lips without such a base for various reasons.
It is also possible to combine the properties of conditioning and decorative lipsticks with one another, i.e. to incorporate conditioning or protective substances into decorative lipsticks.
Since both conditioning and predominantly decorative lipsticks in the prior art sometimes have serious shortcomings, a further object of the present invention was to remedy these shortcomings.
Because of the high sensitivity of the lip region, in particular to ultraviolet radiation as a result of the virtually complete absence of pigments, it is advisable, at least where UV exposure is increased, such as in high mountains, to provide the lip region with protection against UV radiation in the form of corresponding stick light protection formulations. Especially in prior art stick preparations, inorganic pigments are often used as UV absorbers or UV reflectors to protect the lip region against UV rays. These are, in particular, oxides of titanium, but also sometimes of zinc, iron, zirconium, silicon, manganese, aluminium, cerium and mixtures thereof, and also modifications.
A significant shortcoming of the prior art formulations is that, inter alia, because of the low water contents of emulsion sticks which are acceptable per se, it was virtually impossible to incorporate water-soluble UV filter substances into such formulations. A further object of the present invention was thus to make available sticks containing exclusively water-soluble UV filters or water-dispersible pigments (for example titanium dioxide), or combinations of water-soluble and fat-soluble UV filters.
DBP 23 35 549 discloses a process for the preparation of a cosmetic stick based on a W/O emulsion. According to this teaching, a polyhydroxy compound and a nonionogenic, surface-active compound are used to prepare a gel, which is mixed with a cosmetic base, and water is emulsified into the mixture.
However, using this process it is not possible to prepare sticks which satisfy the universal requirements demanded of a cosmetic stick. Furthermore, since this process is not a one-step process, it is notable for further disadvantages.
DE-A 41 28 748 describes cosmetic sticks which are characterized in that they are emulsions and comprise, as essential ingredients, beeswax, one or more esters of a saturated carboxylic acid having 20-40 carbon atoms and a saturated alcohol having 14-34 carbon atoms, water, and optionally further lipids and/or customary auxiliar
Diec Khiet Hien
Klier Manfred
Schreiber Jörg
Wolf Florian
Beiersdorf AG
Howard S.
Norris & McLaughlin & Marcus
Page Thurman K.
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