Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1999-12-14
2002-12-03
Page, Thurman K. (Department: 1615)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S063000, C424S064000, C424S070190, C424S070310, C424S078030, C514S937000, C514S938000, C514S943000, C514S772000, C514S787000, C514S788100
Reexamination Certificate
active
06488941
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 containing a high content of wax and to the use thereof in the cosmetics and dermatological fields, in particular in caring for, treating and/or making up the skin and/or mucous membranes, and more particularly in the treatment of wrinkles and/or fine lines of the skin and/or in the treatment and/or protection of dry skin.
The invention also relates to a process for the preparation of such a composition, wherein at least one stage of the process is carried out using a mixer-extruder.
2. Discussion of the Background
It is known to use waxes in cosmetic creams in the form of emulsions and which are used in the care of human skin, and, in particular, for the antiwrinkle effects contributed by these waxes. Nevertheless, it is difficult to incorporate a high percentage of waxes in these compositions because waxes have a tendency to greatly thicken emulsions. In addition, when a high percentage of waxes is incorporated in an emulsion, the emulsion is very difficult to apply to the skin because it does not slip. Furthermore, a rough effect is produced on the skin. Such an emulsion is therefore of no practical use.
Furthermore, it is also known to incorporate a high percentage of waxes in mascaras. However, compositions of this type cannot be used as a care product because of the above-mentioned disadvantages.
Furthermore, in order to prepare an emulsion containing waxes, it is necessary to melt the waxes in the fatty phase of the emulsion, and in particular if it is desired, for example, to use waxes, such as carnauba waxes, which are particularly advantageous because of their antiwrinkle effect on the skin. In so doing, it is therefore necessary to heat the fatty phase to 80-85° C., which is particularly harmful when it is desired to introduce heat-sensitive compounds thereto.
A need therefore remains for a composition containing a significant percentage of waxes without the above disadvantages.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an O/W emulsion having a high wax content therein.
It is also an object of the present invention to provide a process for preparing an O/W emulsion having a high wax content therein.
It is, moreover, an object of the present invention to provide a method of treating mammalian skin, mucous membranes and/or hair using an o/w emulsion having a high wax content therein.
The above object and others are provided by a composition in the form of an oil-in-water (O/W) emulsion, containing an oily phase dispersed in an aqueous phase, which contains a mixture of at least two nonionic emulsifiers, the mixture being liquid at ambient temperature and having an HLB ranging from about 6 to 13, and wherein the oily phase contains at least about 5% by weight of one or more waxes based on the total weight of the composition, at least one of the waxes having a starting melting temperature of greater than or equal to about 50° C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Quite surprisingly, it has now been discovered, in accordance with the present invention, that it is possible to incorporate a high percentage of waxes in O/W emulsions, while retaining satisfactory fluidity and a pleasant feeling during application on the skin, by preparing the emulsion under cold conditions using a mixture of nonionic emulsifiers, which is liquid at ambient temperature and which has an appropriate HLB (HLB=Hydrophilic Lipophilic Balance), and starting from a soft oily phase containing a high percentage of waxes.
The present invention thus provides a composition in the form of an oil-in-water emulsion containing an oily phase dispersed in an aqueous phase, which contains a mixture of at least two nonionic emulsifiers, the mixture being liquid at ambient temperature and having an HLB ranging from about 6 to 13, and wherein the oily phase contains at least about 5% by weight of one or more waxes based on the total weight of the composition, at least one of the waxes being a wax having a starting melting temperature of greater than or equal to about 50° C.
The composition obtained, although containing a high level of wax, is fresh on application.
The present inventors have particularly sought to avoid the use of ionic emulsifiers, which can be irritating to some skin types, notably to sensitive skin. However, the use of nonionic emulsifiers presents difficulties as there exists no nonionic emulsifier which is liquid at ambient temperature and which has an HLB ranging from about 6 to 13 which makes it possible to achieve the purpose and effect of the prevent invention. The present inventors have surprisingly discovered the effectiveness of using a mixture of nonionic emulsifiers.
The mixture of nonionic emulsifiers which is used in accordance with the present invention must be liquid at ambient temperature, that is to say at a temperature ranging from about 15° C. to 25° C., and have an HLB ranging from about 6 about to 13. It can contain in particular (1) at least one nonionic emulsifier having an HLB equal to or greater than about 13, and (2) at least one nonionic emulsifier having an HLB equal to or less than about 5. In addition, it can optionally contain at least one coemulsifier which may in particular be necessary if the emulsifiers (1) and (2) used are both solids, the coemulsifier then being liquid and making it possible to obtain a liquid mixture.
As is known, the HLB of a mixture of emulsifiers corresponds to the mean of the HLB values of each of the emulsifiers constituting the mixture, taking into account the proportion by weight of these emulsifiers.
Mention may be made, as nonionic emulsifiers with an HLB equal to or less than 5, of, for example, esters of polyols and of a fatty acid having an alkyl chain containing from 12 to 22 carbon atoms, such as esters of fatty acid and of glycerol, of glucose or of sorbitol; oxyethylenated derivatives of esters of polyols and of a fatty acid having an alkyl chain containing from 12 to 22 carbon atoms, which derivatives contain from 1 to 50 oxyethylene groups, such as a complex of triisostearin (triester of glycerol and of isostearic acid) and of PEG-6; ethers of polyethylene glycol and of a fatty alcohol having an alkyl chain containing from 12 to 22 carbon atoms, which ethers contain from 1 to 50 oxyethylene groups, such as oleyl ethers and in particular oleth-25 (25 oxyethylene groups), and their mixtures.
Use may advantageously be made, as nonionic emulsifiers with an HLB equal to or less than about 5, of those which are liquid at ambient temperature, such as polyol fatty esters and fatty ethers with a branched or unsaturated chain containing from 12 to 22 carbon atoms and, in particular, sorbitan monoisostearate, such as the product sold under the name “Arlacel 987” by the company ICI, sorbitan mono/dioleate, such as the product sold under the name “Arlacel 83” by the company ICI, the complex of triisostearin and of PEG-6, such as the product sold under the name “Labrafil isostearic” by the company Gattefossé, decaglyceryl pentaisostearate, such as the product sold under the name “Nikkol Decaglyn 5-IS” by the company Nikko Chemical, or methyl glucose dioleate, such as the product sold under the name “Isolan DO” by the company Goldschmidt.
Mention may be made, as nonionic emulsifiers with an HLB equal to or greater than about 13, of, for example, esters of polyethylene glycol and of a fatty acid having an alkyl chain containing from 12 to 22 carbon atoms, which esters contain from 5 to 100 and preferably from 20 to 60 oxyethylene groups, such as PEG-40 stearate; ethers of polyethylene glycol and of a fatty alcohol having an alkyl chain containing from 12 to 22 carbon atoms, which ethers contain from 5 to 100 and preferably from 10 to 30 oxyethylene groups, such as ceteareth-25 or ceteth-25; esters of sorbitan and of a fatty acid having an alkyl chain containing from 12 to 22 carbon atoms, which esters comprise from 0 to 100 a
Burnier Veronique
Roulier Veronique
Channavajjala Lakshmi
L'Oreal
Page Thurman K.
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