Drug – bio-affecting and body treating compositions – Topical sun or radiation screening – or tanning preparations
Reexamination Certificate
2002-01-28
2003-05-27
Dodson, Shelley A. (Department: 1616)
Drug, bio-affecting and body treating compositions
Topical sun or radiation screening, or tanning preparations
C424S060000, C424S400000, C424S401000
Reexamination Certificate
active
06569410
ABSTRACT:
BACKGROUND OF THE INVENTION
Under the influence of solar radiation, the pigmenting of normal skin leads to the formation of melanins. Exposure to long-wave UV-A light results in darkening of the melanins present in the epidermis without any harmful effects while exposure to short-wave UV-B radiation results in the formation of new melanin. However, before the protective pigment can be formed, the skin is exposed to the effect of unfiltered radiation which can lead to reddening of the skin (erythema), inflammation of the skin (sunburn) or even to blisters, depending on the exposure time. The strain on the organism associated with such skin lesions, for example in connection with the distribution of histamines, can additionally lead to headache, lassitude, fever, heart and circulation problems and the like. The consumer seeking to protect himself/herself against the harmful effects of the sun can choose from a range of products which, for the most part, are oils and milky emulsions which, besides a few skin-care ingredients, contain above all UV filters.
Nevertheless, there is a continuing need on the market for products with an improved performance spectrum. Of particular interest in this regard are preparations which enable relatively large amounts of UV filters to be incorporated without any phase separation or sedimentation occurring during storage. Where relatively large quantities of titanium dioxide are incorporated, a formulation produced by the phase inversion temperature method, as described for example in European patent application EP 0 667 144 A1 (L'Oreal), tends to separate the dispersed solid very quickly. Another problem is that many UV filters are capable of interacting with the other ingredients of the formulation, resulting in a chemical reaction and also in a reduction in storage stability. Finally, consumers prefer transparent formulations which show high dermatological compatibility, even when applied to very sensitive skin.
Accordingly, the complex problem addressed by the present invention was to provide sun protection compositions which would be distinguished by particular phase stability, stability in storage on exposure to heat and compatibility with sensitive skin.
BRIEF SUMMARY OF THE INVENTION
The present invention relates, in general, to cosmetics and more particularly to sun protection compositions containing special esters of hydroxycarboxylic acids together with UV protection filters or pigments and to the use of the mixtures in sun protection compositions.
It has surprisingly been found that the special hydroxycarboxylic acid esters are capable of both stably emulsifying liquid UV protection factors and reliably dispersing even relatively large quantities of crystalline filters or pigments, even on exposure to heat. The invention includes the observation that the hydroxycarboxylic acid esters also considerably improve the photostability of a large number of UV protection filters.
DETAILED DESCRIPTION OF THE INVENTION
Esters of hydroxycarboxylic acids and alkyl and alkenyl oligoglycosides are known nonionic surfactants which correspond to formula (I):
where X is hydrogen or a CH
2
COOR
3
group, Y is hydrogen or a hydroxyl group, R
1
, R
2
and R
3
independently of one another represent hydrogen, an alkali metal or alkaline earth metal, ammonium, alkyl ammonium, hydroxyalkyl ammonium, glucammonium or the residue of an alkyl and/or alkenyl oligoglycoside corresponding to formula (II):
R
4
O—[G]
p
(II)
in which R
4
is an alkyl and/or alkenyl group 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, with the provisos that, where X is a CH
2
COOR
3
group, Y is hydrogen and at least one of the substituents R
1
, R
2
and R
3
is a glycoside unit. The production and use of these compounds as high-foaming surfactants in cosmetic preparations is known from European patent EP 0 258 814 B1 (Auschem) to which reference is made here.
The acid component of the nonionic surfactants may be derived from malic acid, tartaric acid or citric acid and mixtures thereof. Depending on the number of hydroxyl groups present in the acid component, mono-, di- or triesters and technical mixtures thereof may be used. However, monoesters or high-monomer mixtures, which may be obtained by the expert in accordance with the teaching of the above-cited EP 0 258 814 B1, are preferably used.
The alkyl and/or alkenyl oligoglycoside component may be derived from aldoses or ketoses containing 5 or 6 carbon atoms, preferably glucose. Accordingly, the preferred nonionic surfactants are esters of alkyl and/or alkenyl oligoglucosides. The index p in general formula (II) 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 broken number. Esters of which the alkyl and/or alkenyl oligoglycoside component has an average degree of oligomerization p of 1.1 to 3.0 are preferably used. Alkyl and/or alkenyl oligoglycoside esters 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. C
9-11
or C
8-10
alkyl oligoglucoside esters with a DP of 1 to 3, of which the alkyl group is derived from corresponding oxoalcohols or alcohols 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, 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 oligoglucoside esters based on hydrogenated C
12/14
coconut oil fatty alcohol having a DP of 1 to 3 are preferred. Such products are commercially obtainable as Eucarol®.
The invention includes the observation that mixtures of hydroxycarboxylic acid alkyl and/or alkenyl glycoside esters and alkyl and/or alkenyl oligoglycosides together with UV protection factors give particularly stable emulsions. In the most simple cases, these ternary mixtures may be prepared by mixing the three components. In one particular embodiment of the invention, however, UV protection factors or UV protection pigments are used together with hydroxycarboxylic acid glycoside esters which still contain 1 to 50, preferably 5 to 25 and more particularly 10 to 15% by weight of unesterified glycosides. Normally, the preparations may contain the hydroxycarboxylic acid esters in total quantities of 0.1 to 15, preferably 0.5 to 10 and more particularly 1 to 5% by weight.
UV Protection Factors
UV protection factors are, for example, organic substances (light filters) which are liquid or crystalline at room temperature and which are capable of absorbing ultraviolet radiation and of releasing the energy absorbed in the form of longer-wave radiation, for example heat. UV-B filters can be oil-soluble or water-soluble. The following are examples of oil-soluble substances:
3-benzylidene camphor or 3-benzylidene norcamphor and derivatives thereof, f
Fabry Bernd
Hensen Hermann
Koester Josef
Schmid Karl Heinz
Cognis Deutschland GmbH
Dodson Shelley A.
Ettelman Aaron R.
LandOfFree
Sun protection compositions containing UV protection factors... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sun protection compositions containing UV protection factors..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sun protection compositions containing UV protection factors... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3027752