Compositions – Preservative agents – Anti-oxidants or chemical change inhibitants
Reexamination Certificate
1997-11-06
2003-02-11
Raymond, Richard L. (Department: 1624)
Compositions
Preservative agents
Anti-oxidants or chemical change inhibitants
C544S196000, C544S197000, C544S198000, C544S199000, C514S241000, C514S880000, C514S881000, C424S070100, C424S070900, C424S060000, C424S401000, C524S100000
Reexamination Certificate
active
06517742
ABSTRACT:
The invention relates to new s-triazine derivatives substituted by at least one silicone group and at least one aminobenzylidenecamphor, aminobenzalmalonate, aminobenzoate, or alternatively aminobenzotriazole, aminobenzimidazole, aminobenzoxazole, aminobenzothiazole, aminosalicylate, aminocinnamate and/or aminocinnamonitrile group; these compounds being more particularly employable as organic sunscreen agents in cosmetic compositions intended for protecting the skin and hair against ultraviolet radiation. The invention also relates to the use of these compounds in the above-mentioned cosmetic applications, and to the cosmetic compositions with improved properties containing them.
It is known that light radiation with wavelengths of from 280 nm to 400 nm makes possible tanning of the human epidermis and that rays with wavelengths more particularly of from 280 to 320 nm, known under the name UV-B, cause skin burns and erythemas which may be harmful to the development of a natural tan. For these reasons, and for aesthetic reasons, there is a constant demand for means of controlling this natural tanning with a view to thus controlling the color of the skin; it is therefore advisable to screen out this UV-B radiation.
It is also known that UV-A rays, with wavelengths of from 320 to 400 nm, which cause tanning of the skin, are liable to induce an adverse, change in the latter, especially in the case of sensitive skin or of skin which is continually exposed to solar radiation. UV-A rays cause in particular a loss of elasticity of the skin and the appearance of wrinkles, leading to premature skin aging. They promote triggering of the erythemal reaction or amplify this reaction in certain individuals and may even be the cause of phototoxic or photoallergic reactions. Thus, for aesthetic and cosmetic reasons, such as retaining the natural elasticity of he skin, for example, increasing numbers of people wish to control the effect of UV-A rays on their skin. It is thus desirable also to screen out UV-A radiation.
Many compounds intended for the photoprotection (UV-A and/or UV-B) of the skin have been provided to date.
Most of them are aromatic compounds exhibiting absorption of UV rays in the region from 280 to 315 nm or in the region from 315 to 400 nm or alternatively in both of these two regions. They are most often formulated in anti-sun compositions which are provided in the form of an emulsion of oil-in-water type (that is to say a cosmetically acceptable vehicle composed of a continuous aqueous dispersing phase and of a non-continuous oily dispersed phase) and which thus contain, at various concentrations, one or more conventional lipophilic and/or hydrophilic organic screening agents with an aromatic functional group which are capable of selectively absorbing harmful UV radiation, these screening agents (and their amounts) being selected as a function of the desired sun protection factor (the sun protection factor being expressed mathematically by the ratio of the irradiation time necessary to reach the erythemogenic threshold with the UV screening agent to the time necessary to reach the erythemogenic threshold without UV screening agent).
In addition to their screening power, these compounds with an anti-UV activity must also exhibit good cosmetic properties in the compositions which contain them, good solubility in the usual solvents, and in particular fatty substances such as oils and fats, and good resistance to water and to perspiration (persistence).
Among all the aromatic compounds which have been recommended for this purpose, mention may in particular be made of derivatives of p-aminobenzoic acid, derivatives of benzylidenecamphor, derivatives of cinnamic acid and derivatives of benzalmalonate. However, some of these substances do not exhibit all the properties required for suitable use as UV screening agents in anti-sun compositions. In particular, their intrinsic screening power may be insufficient, their solubility in the various types of formulations used for sun projection is not always sufficiently good (in particular liposolubility), they may not possess sufficient stability to light (photostability). and they may also exhibit poor resistance to water and to sweat. It is also desirable for these screening substances not to penetrate into the skin.
Thus, in the more specific case of screening substances of benzalmalonate, benzotriazole or benzylidenecamphor type, attempts have been made to obtain products with improved properties, in particular with respect to their liposolubility and their screening power,, by attaching, by grafting, one or more screening benzylidenecamphor, benzotriazole or benzalmalonate groups to an s-triazine. This technique, described in Patent Applications EP 0,507,691 and EP 0,507,692, certainly results in advantageous compounds but the liposoluble nature of the latter may still appear to be insufficient and, moreover, in order to obtain satisfactory screening properties with this type of product, it is often necessary to employ relatively large amounts of these screening agents, which is reflected by poor cosmetic properties with respect to the formulations which contain them.
Likewise, in the documents EP 0,517,104 and U.S. Pat. No. 4,724,137, attempts have been made to increase the SPF of derivatives of p-aminobenzoic acid by grafting three p-aminobenzoate groups onto an s-triazine. Compounds exhibiting a good SPF but with very low liposolubility are obtained. The formulation of such compounds proves to be difficult and tedious and requires the addition of solubilizing substances, sometimes in large amounts.
The aim of the present invention is to solve the above problems by providing new compounds, of silane or siloxane s-triazine type, with an aminobenzylidenecamphor, aminobenzalmalonate, aminobenzoate, or alternatively aminobenzotriazole,,aminobenzimidazole, aminobenzoxazole, aminobenzothiazole, aminosalicylate, aminocinnamate and/or aminocinnamonitrile functional group, which exhibit improved properties, in particular with respect to their solubility in fatty substances and their intrinsic absorption power with respect to UV radiation.
More specifically still, it has been found, according to the present invention, that, by grafting onto an s-triazine, on the one hand, at least one specific silicone chain or one specific silane and, on the other hand, one or more screening chromophores, it is possible to produce new compounds which overcome the disadvantages of the screening agents of the prior art, these new compounds exhibiting, in addition to very high screening properties, very good solubility in the usual organic solvents, in particular fatty substances such as oils, and excellent cosmetic properties, making them particularly suitable for use as sunscreen agents in, or for the preparation of, cosmetic compositions intended for the protection of the skin and/or hair against ultraviolet radiation.
Screening chromophore is understood to mean, within the meaning of the present invention, a group which absorbs UV radiation in the region from 280 nm to 400 nm. Screening chromophores which are particularly well suited to the preparation of the compounds according to the invention are derivatives of aminobenzylidenecamphor, aminobenzalmalonate, aminobenzoate, aminobenzotriazole, aminobenzimidazole, aminobenzoxazole, aminobenzothiazole, aminosalicylate, aminocinnamate, and/or aminocinnamonitrile.
The first subject of the present invention is thus new compounds which are characterized in that they correspond to the following general formula (I):
in which:
R
1
represents an —NH—F radical,
R
2
represents an —NH—Z—W radical,
R
3
is R
1
, R
2
, a linear or branched C
1
-C
20
alkyl radical, a linear or branched C
2
-C
20
hydroxyalkyl radical, a linear or branched C
1
-C
20
alkoxy radical, the NHR
8
radical or the N(R
8
)
2
radical, with R
8
independently being a linear or branched C
1
-C
20
alkyl radical
F represents a screening chromophore,
Z represents a divalent radical providing the connection between —NH— and —W,
W represents eit
Leduc Madeleine
Richard Herve
Balasubramanian Venkataraman
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
L'Oreal
Raymond Richard L.
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