Drug – bio-affecting and body treating compositions – Topical sun or radiation screening – or tanning preparations
Reexamination Certificate
1999-05-10
2001-02-06
Chang, Ceila (Department: 1625)
Drug, bio-affecting and body treating compositions
Topical sun or radiation screening, or tanning preparations
C424S060000, C424S063000, C424S070210, C424S085100
Reexamination Certificate
active
06183728
ABSTRACT:
The subject of the present invention is a composition for screening out ultraviolet radiation, comprising, in association, at least one nanopigment of metallic oxide and at least one UV-screening fat-soluble polymer.
It is known that light radiation with wavelengths of between 280 and 400 nm permit the tanning of the human epidermis and that rays with wavelengths of between 280 and 320 nm, known by the name UV-B, also cause erythemas and skin burns which can hamper the development of the tan.
However, while UV-B rays with wavelengths of between 280 and 320 nm play a preponderant part in the production of solar erythema and must be screened out, it is nevertheless a fact that UV-A rays with wavelengths of between 320 and 400 nm which cause tanning of the skin are also capable of inducing its degradation especially in the case of a sensitive skin or a skin continuously exposed to solar radiation. UV-A rays cause in particular a loss of elasticity of the skin and the appearance of wrinkles which result in early ageing. They promote the onset of the erythemal reaction or amplify this reaction in certain subjects and may even be responsible for phototoxic or photoallergic reactions.
Compounds are known which have the property of absorbing ultraviolet radiation in the erythemal region while allowing the radiation responsible for tanning to pass through and it has already been proposed to use such compounds as “sunscreen” agents in cosmetic compositions which promote the acquisition of skin tan while avoiding skin burns and irritations.
Synthetic or natural carbon-containing polymers and siloxane polymers carrying an ultraviolet-absorbing group are also known which possess the advantage of reducing or even suppressing the penetration of the screening compound into the body.
Metallic oxides such as titanium oxide are useful because of their ultraviolet ray diffusion and reflection properties over a broad band. However, the effectiveness of the cosmetic compositions containing only metallic oxides, expressed by the solar protection factor which is generally called “protection index” or PI, is inadequate for very sensitive skins or skins continuously exposed to solar radiation, especially with respect to the UV-B protection index.
The protection index or PI may be expressed by the ratio of the irradiation time required to reach the erythematogenic threshold with the UV-screening agent to the time required to reach the erythematogenic threshold without a UV-screening agent.
Cosmetic compositions containing only “screening polymers” have the same disadvantage.
In the following text, a polymer of hydrocarbon or siloxane structure, carrying at least one ultraviolet-absorbing group, will be called “screening polymer”.
Moreover, at the industrial level, it is of course advantageous to have UV-screening agents which make it possible, at low concentrations, to obtain antisun compositions with a high protection index.
The Applicant has just discovered that by combining at least one nanopigment of metallic oxide, having a particle size less than 100 nm, with at least one fat-soluble screening polymer, in a cosmetically acceptable carrier, there was surprisingly obtained, for a composition containing a given concentration of the nanopigment and the screening polymer taken together, a protection index, especially a UV-B protection index, substantially greater than the protection indices of compositions containing either a nanopigment, or a screening polymer, at the same concentration and in the same carrier.
The subject of the present invention is therefore a cosmetic composition for screening out ultraviolet radiation with wavelengths of between 280 and 400 nm, which contains at least one nanopigment of metallic oxide and at least one screening polymer chosen from fat-soluble polymers with a hydrocarbon structure and polymers with a siloxane structure, in a cosmetically acceptable carrier.
The subject of the present invention is also a process for protecting the human epidermis and the hair against ultraviolet radiation with wavelengths of between 280 and 400 nm, which consists in applying to the skin an effective amount of the abovementioned screening cosmetic composition comprising, in association, at least one nanopigment of metallic oxide and at least one fat-soluble screening polymer.
The pigments of metallic oxides are chosen from titanium, zinc, cerium, zirconium or iron oxides or mixtures thereof. In the present application, “nanopigments” are understood to mean pigments with a mean diameter of less than 100 nanometers, preferably of between 5 and 50 nanometers. These nanopigments may be coated or uncoated.
The coated pigments are pigments which have undergone one or more surface treatments of a chemical, electronic, mechanicochemical and/or mechanical nature with compounds, as described for example in Cosmetics & Toiletries, February 1990, Vol. 105, p. 53-64, such as amino acids, beeswax, fatty acids, fatty alcohols, anionic surfactants, lecithins, sodium, potassium, zinc, iron or aluminum salts of fatty acids, metallic alkoxides (of titanium or aluminum), polyethylene, silicones, proteins (collagen, elastin), alkanolamines, silicon oxides, metallic oxides or sodium hexametaphosphate.
The coated pigments are more particularly titanium oxides coated:
with silica, such as the product “SUNVEIL” from the company IKEDA,
with silica and iron oxide, such as the product “SUNVEIL F” from the company IKEDA,
with silica and alumina, such as the products “MICROTITANIUM DIOXIDE MT 500 SA” and “MICROTITANIUM DIOXIDE MT 100 SA” from the company TAYCA, “TIOVEIL” from the company TIOXIDE,
with alumina, such as the products “TIPAQUE TTO-55(B)” and “TIPAQUE TTO-55(A)”, from the company ISHIHARA, and “UVT 14/4” from the company KEMIRA,
with alumina and aluminum stearate, such as the product “MICROTITANIUM DIOXIDE MT 100 T” from the company TAYCA,
with alumina and aluminum laurate, such as the product “MICROTITANIUM DIOXIDE MT 100 S” from the company TAYCA,
with iron oxide and iron stearate, such as the product “MICROTITANIUM DIOXIDE MT 100 F” from the company TAYCA,
with zinc oxide and zinc stearate such as the product “BR 351” from the company TAYCA,
with silica, alumina and silicone, such as the products “MICROTITANIUM DIOXIDE MT 600 SAS” and “MICROTITANIUM DIOXIDE MT 500 SAS” from the company TAYCA,
with silica, alumina, aluminum stearate and silicone, such as the product “STT-30-D-S” from the company TITAN KOGYO,
with alumina and silicone, such as the product “TIPAQUE TTO-55(S)” from the company ISHIHARA,
with triethanolamine, such as the product “STT-65-S” from the company TITAN KOGYO,
with stearic acid such as the product “TIPAQUE TTO-55(C)” from the company ISHIHARA,
with sodium hexametaphosphate, such as the product “MICROTITANIUM DIOXIDE MT 150 W” from the company TAYCA.
There may also be mentioned the mixtures of metallic oxides, especially of titanium dioxide and cerium dioxide, including the equiponderal mixture of titanium dioxide and cerium dioxide, coated with silica, which is sold by the company IKEDA under the name “SUN-VEIL A” as well as the mixture of titanium dioxide and zinc dioxide coated with alumina, silica and silicone, such as the product “M 261” sold by the company KEMIRA, or coated with alumina, silica and glycerin, such as the product “M 211” sold by the company KEMIRA.
The uncoated titanium oxides are for example sold by the company TAYCA under the trade names “MICROTITANIUM DIOXIDE MT 500 B” or “MICROTITANIUM DIOXIDE MT 600 B”, by the company DEGUSSA under the name “P 25”, by the company WACKHERR under the name “Transparent titanium oxide PW”, by the company MIYOSHI KASEI under the name “UFTR” and by the company TOMEN under the name “ITS”.
The uncoated zinc oxides are for example sold by the company SUMITOMO under the name “ULTRA FINE ZINC OXIDE POWDER”, by the company PRESPERSE under the name “FINEX 25” or by the company IKEDA under the name “MZO-25”.
The uncoated cerium oxide is sold under the name “COLLOIDAL CERIUM OXIDE” by the company RHONE POULENC.
The iron oxides are fo
Forestier Serge
Hansenne Isabelle
Chang Ceila
Jacobson Price Holman & Stern PLLC
L'Oreal
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