Drug – bio-affecting and body treating compositions – Preparations characterized by special physical form – Cosmetic – antiperspirant – dentifrice
Reexamination Certificate
1999-06-04
2002-02-19
Bawa, Raj (Department: 1619)
Drug, bio-affecting and body treating compositions
Preparations characterized by special physical form
Cosmetic, antiperspirant, dentifrice
C424S059000, C424S060000, C424S078030, C514S937000
Reexamination Certificate
active
06348202
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to cosmetic preparations, preferably self-tanning preparations, containing selected nonionic emulsifiers and dihydroxyacetone and to the use of these emulsifiers for the production of the preparations.
2. Discussion of Related Art
In the modern meritocracy, many people associate a tanned skin with notions of “youth” and “dynamism”. For consumers who are unable or do not wish to expose themselves either to natural or to artificial UV radiation, but still want a tanned skin, the cosmetic industry offers self-tanning preparations most of which contain dihydroxyacetone (DHA) as their active ingredient.
One problem of using DHA is that its stability in cosmetic products is often inadequate so that unwanted secondary reactions, for example the formation of formaldehyde or formic acid, can occur. This can generally be prevented by microencapsulation [Euro Cosm. No. 11, 26 (1995)]. Cosmetic o/w emulsions containing DHA which have a particle size of 100 to 1,000 nm are known from European patent application EP-A1 0 689 125 (L'Oreal). According to European patent application EP-A1 0 715 845 (L'Oreal), self-tanning preparations containing dihydroxyacetone are obtained by using a mixture of an alkyl polyglucoside and a fatty alcohol as emulsifier. In addition, compositions containing oils and ethylene oxide/propylene oxide block polymers in addition to DHA are known from European patent application EP-A1 0 671 159 (Shiseido).
Another problem is the fact that the preparations are generally homogeneous at room temperature and have a constant viscosity, but quickly develop an irreversible tendency to separate and lose their viscosity when heated, for example, to 35-40° C. If a preparation such as this is applied, the self-tanning ingredients are unevenly distributed over the skin with the result that the tanning effect appears patchy. It will readily be appreciated that this is not tolerable to the consumer.
Accordingly, the problem addressed by the present invention was to provide cosmetic preparations containing dihydroxyacetone which would be simultaneously distinguished by high dermatological compatibility, a favorable feeling on the skin and, in particular, by high stability in storage at relatively high temperatures. Accordingly, a key aspect of the problem addressed by the invention was to overcome the disadvantages of the prior art and reliably to prevent both the chemical decomposition of the DHA and the uneven distribution of the dihydroxyacetone when stored at elevated temperature in the preparations.
DESCRIPTION OF THE INVENTION
The present invention relates to cosmetic preparations containing
(a) alkyl and/or alkenyl oligoglycosides,
(b) polyol poly-12-hydroxystearates and
(c) dihydroxyacetone.
It has surprisingly been found that cosmetic preparations containing dihydroxyacetone which are distinguished by excellent stability in storage, even at elevated temperatures, can be obtained by using mixtures of alkyl and/or alkenyl oligoglycosides and polyol poly-12-hydroxystearates as nonionic emulsifiers. This ensures that the homogeneous, viscous compositions do not lose their stability, even in direct sunlight, and can be easily and reliably used by the consumer. At the same time, high stability of the DHA is observed without any need for microencapsulation.
Alkyl and/or alkenyl oligoglycosides
Alkyl and alkenyl oligoglycosides are known nonionic surfactants which correspond to formula (I):
R
1
O-[G]
p
(I)
where R
1
is an alkyl and/or alkenyl radical containing 4 to 22 carbon atoms, G is a sugar unit containing 5 or 6 carbon atoms and p is a number of 1 to 10. They may be obtained by the relevant methods of preparative organic chemistry. EP-A1-0 301 298 and WO 90/03977 are cited as representative of the extensive literature available on this subject.
The alkyl and/or alkenyl oligoglycosides may be derived from aldoses or ketoses containing 5 or 6 carbon atoms, preferably glucose. Accordingly, the preferred alkyl and/or alkenyl oligoglycosides are alkyl and/or alkenyl oligoglucosides. The index p in general formula (I) indicates the degree of oligomerization (DP), i.e. the distribution of mono-and oligoglycosides, and is a number of 1 to 10. Whereas p in a given compound must always be an integer and, above all, may assume a value of 1 to 6, the value p for a certain alkyl oligoglycoside is an analytically determined calculated quantity which is generally a non whole number. Alkyl and/or alkenyl oligoglycosides having an average degree of oligomerization p of 1.1 to 3.0 are preferably used. Alkyl and/or alkenyl oligoglycosides having a degree of oligomerization of less than 1.7 and, more particularly, between 1.2 and 1.4 are preferred from the applicational point of view.
The alkyl or alkenyl radical R
1
may be derived from primary alcohols containing 4 to 11 and preferably 8 to 10 carbon atoms. Typical examples are butanol, caproic alcohol, caprylic alcohol, capric alcohol and undecyl alcohol and the technical mixtures thereof obtained, for example, in the hydrogenation of technical fatty acid methyl esters or in the hydrogenation of aldehydes from Roelen's oxosynthesis. Alkyl oligoglucosides having a chain length of C
8
to C
10
(DP=1 to 3), which are obtained as first runnings in the separation of technical C
8-18
coconut oil fatty alcohol by distillation and which may contain less than 6% by weight of C
12
alcohol as an impurity, and also alkyl oligoglucosides based on technical C
9/11
oxoalcohols (DP=1 to 3) are preferred. In addition, the alkyl or alkenyl radical R
1
may also be derived from primary alcohols containing 12 to 22 and preferably 12 to 14 carbon atoms. Typical examples are lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl alcohol, stearyl alcohol, isostearyl alcohol, oleyl alcohol, elaidyl alcohol, petroselinyl alcohol, arachyl alcohol, gadoleyl alcohol, behenyl alcohol, erucyl alcohol, brassidyl alcohol and technical mixtures thereof which may be obtained as described above. Alkyl oligoglucosides based on hydrogenated C12 /
14
coconut oil fatty alcohol having a DP of 1 to 3 are preferred.
Polyol poly-12-hydroxystearates
The polyol poly-12-hydroxystearates are known substances which are marketed by Henkel KGaA of Dusseldorf, FRG, for example under the names of “Dehymuls® PGPH” and “Eumulgin® VL 75” (mixture with Coco Glucosides in a ratio by weight of 1:1). Reference is also made in this connection to International patent application WO 95/34528 (Henkel). The polyol component of the emulsifiers may be derived from substances which contain at least 2, preferably 3 to 12 and more preferably 3 to 8 hydroxyl groups and 2 to 12 carbon atoms. Typical examples are
(a) glycerol and polyglycerol;
(b) alkylene glycols such as, for example, ethylene glycol, diethylene glycol, propylene glycol;
(c) methylol compounds such as, in particular, trimethylol ethane, trimethylol propane, trimethylol butane, pentaerythritol and dipenta-erythritol;
(d) alkyl oligoglucosides containing 1 to 22, preferably 1 to 8 and more preferably 1 to 4 carbon atoms in the alkyl group such as, for example, methyl and butyl glucoside;
(e) sugar alcohols containing 5 to 12 carbon atoms such as, for example, sorbitol or mannitol,
(f) sugars containing 5 to 12 carbon atoms such as, for example, glucose or sucrose;
(g) amino sugars such as, for example, glucamine.
Among the emulsifiers suitable for use in accordance with the invention, reaction products based on polyglycerol are particularly important by virtue of their excellent applicational properties. It has proved to be of particular advantage to use selected polyglycerols which have the following homolog distribution (the preferred ranges are shown in brackets):
glycerol
5 to 35 (15 to 30) % by weight
diglycerols
15 to 40 (20 to 32) % by weight
triglycerols
10 to 35 (15 to 25) % by weight
tetraglycerols
5 to 20 (8 to 15) % by weight
pentaglycerols
2 to 10 (3 to 8) % by weight
oligoglycerols
to 1
Bawa Raj
Drach John E.
Ettelman Aaron R.
Henkel Kommanditgesellschaft auf Aktien
Roland Thomas F.
LandOfFree
Cosmetic compositions containing dihydroxyacetone and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Cosmetic compositions containing dihydroxyacetone and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Cosmetic compositions containing dihydroxyacetone and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2978329