Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1999-12-01
2001-07-24
Kishore, Gollamudi S. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C264S004100, C264S004300, C264S004600, C424S078020, C424S078030
Reexamination Certificate
active
06264965
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a composition in the form of an oil-in-water (O/W) emulsion comprising a high content of wax, and to its uses in cosmetics and dermatology, in particular for caring for, treating and/or making up the skin and/or mucous membranes, and more particularly for treating wrinkles and/or fine lines of the skin and/or for treating and/or protecting dry skin. The invention also relates to a process for preparing this composition, where at least one step of the process is carried out using a mixer-extruder.
2. Description of the Invention
It is well-known to use waxes in cosmetic creams in the form of emulsions intended for caring for human skin, in particular for the anti-wrinkle effects provided by these waxes. However, it is difficult to incorporate a high percentage of waxes into these compositions since waxes have a tendency to thicken the emulsions considerably. In addition, when a high percentage of waxes is incorporated into an emulsion, the emulsion is very difficult to apply to the skin since it does not slide. Moreover, a coarse effect appears on the skin. Such an emulsion is therefore unacceptable to users.
Furthermore, it is known to incorporate a high percentage of waxes into mascaras. However, compositions of this type cannot be used as care products on account of the drawbacks mentioned above.
Moreover, to prepare an emulsion containing waxes, it is necessary to melt the waxes in the fatty phase of the emulsion, in particular if it is desired, for example, to use waxes such as carnauba waxes which are particularly advantageous for their anti-wrinkle effect on the skin. It is thus necessary to heat the fatty phase up to 80-85° C., which is particularly harmful when it is desired to introduce heat-sensitive compounds.
Therefore, a need exists for a composition containing a high percentage of waxes which is free of the drawbacks of the compositions described above.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an oil-in-water emulsion that contains wax.
It is another object of the present invention to provide methods of treating skin, especially human skin, using the oil-in-water emulsion that contains wax.
The inventors having discovered, surprisingly, that a high percentage of waxes can be incorporated into O/W emulsions while at the same time retaining satisfactory fluidity and a pleasant sensation when it is applied to the skin, by preparing the emulsion without heating, using an anionic emulsifier which is liquid at room temperature and starting with a soft oily phase containing a high percentage of waxes.
Accordingly, the objects of the invention, and others, maybe accomplished with a creamy composition in the form of an oil-in-water emulsion and comprising:
an oily phase dispersed in an aqueous phase,
at least one anionic emulsifier which is a liquid at room temperature, and
at least 5% by weight, relative to the total weight of the composition, of at least one wax,
where the oily phase is in the form of a soft paste at room temperature.
The objects of the present invention may also be accomplished with a method of treating wrinkles and/or fine lines of the skin, comprising applying an effective amount of the inventive composition to the skin.
The objects of the present invention may also be accomplished with a method of treating and/or protecting dry skin, comprising applying the effective amount of the inventive composition to the skin.
The objects of the present invention may also be accomplished with a method of preparing the inventive composition, comprising dispersing the oily phase in the aqueous phase.
The objects of the present invention may also be accomplished with a method of preparing the inventive composition, comprising:
(a) preparing the oily phase in the form of a soft paste by mixing the waxes and oils,
(b) heating the oily phase to a temperature at which it melts,
(c) introducing melted oily phase and the other constituents of the oily phase into a mixer-screw extruder subjected to a temperature gradient ranging from 80° C. to 20° C.,
(d) blending the mixture obtained while at the same time cooling it to room, temperature while it is conveyed to the outlet of the mixer-extruder to produce a soft paste,
(e) incorporating the emulsifier and, optionally, if present, the co-emulsifier into the soft paste obtained from (d), and
(f) incorporating the mixture from (e) into the aqueous phase.
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 composition of the present invention is in the form of a cream, i.e. a soft product, as opposed to the solid structure of a stick. A cream has a viscosity at room temperature (about 20-25° C.) between 1 to 10 Pa.s, measured with a Rheomat 180. This range includes all specific values and subranges therebetween, such as 2, 3, 5 and 8 Pa.s.
Although containing a large amount of wax, the composition obtained feels fresh when applied.
The anionic emulsifier used in the composition of the invention is liquid at room temperature, i.e. at a temperature ranging from 15° C. to 25° C. It can be chosen in particular from the group of anionic surfactants containing a phosphate group, which are liquid at room temperature, such as mono-, di- and/or triesters of phosphoric acid and of a C
12
to C
22
fatty alcohol, i.e. of an alcohol having an alkyl chain containing from 12 to 22 carbon atoms (inclusive of all specific values and subranges therebetween, such as 14, 16, 18 and 20 carbon atoms), and mono-, di- and/or triesters of phosphoric acid and of an ethoxylated fatty alcohol, having a fatty chain containing from 12 to 22 carbon atoms (inclusive of all specific values and subranges therebetween, such as 14, 16 from 20 carbon atoms) and a number of ethoxylated units ranging from 1 to 100 and preferably from 4 to 25 (inclusive of all specific values and subranges therebetween, such as 2, 5, 10, 15, 35, 50, 75 and 90).
Anionic emulsifiers that are liquid at room temperature which are preferred are oleyl phosphate (mixture of mono- and diester of phosphoric acid and of oleyl alcohol), trioleyl phosphate, dilaureth-4 phosphate (mixture of diesters of phosphoric acid and of polyethylene glycol ether and of lauryl alcohol, containing 4 oxyethylenated groups), trioleth-8 phosphate (mixture of triesters of phosphoric acid and of ether of polyethylene glycol and of oleyl alcohol, containing 8 oxyethylenated groups), triceteareth-4 phosphate (mixture of triesters of phosphoric acid and of ether of polyethylene glycol and of cetyl and stearyl alcohols, containing 4 oxyethylenated groups), the monoester of phosphoric acid and of stearic and isostearic acid (CTFA name: octyldecyl phosphate) sold under the name Hostaphat CG 120 by Clariant, and mixtures thereof. According to one preferred embodiment of the invention, octyldecyl phosphate is used.
The amount of emulsifier in the composition according to the invention generally ranges from 0.1 to 10% by weight of active material and preferably from 1 to 5% by weight of active material relative to the total weight of the composition. These ranges includes all specific values and subranges therebetween, such as 0.2, 0.5, 2, 3, and 8% by weight.
A co-emulsifier can optionally be added to the anionic emulsifier which is liquid at room temperature, provided that the mixture of the emulsifier and the co-emulsifier is liquid at room temperature.
Co-emulsifiers which may be used include, for example, fatty alcohols comprising a branched or unsaturated chain containing from 8 to 22 carbon atoms (inclusive of all specific values and subranges therebetween, such as 10, 12, 14, 16, 18 and 20 carbon atoms), such as isostearyl alcohol, fatty acids comprising a branched or unsaturated chain containing from 8 to 22 carbon atoms (inclusive of all specific values and subranges therebetween such as 10, 12,
Roulier Veronique
Simon Pascal
Di Nola-Baron Liliana
Kishore Gollamudi S.
L'Oreal
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
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