Drug – bio-affecting and body treating compositions – Topical sun or radiation screening – or tanning preparations
Reexamination Certificate
2000-06-08
2001-10-02
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
06296835
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present invention relates to novel cosmetic compositions for topical application, for the photoprotection of the skin and/or the hair against ultraviolet radiation (such compositions hereinafter simply designated “sunscreen” or “antisun” compositions), and to the use of same for the cosmetic applications indicated above.
This invention more especially relates to the aforesaid sunscreen/antisun compositions comprising, in a cosmetically acceptable support (vehicle, diluent or carrier) unique immixture of (a) at least one bis-hydroxyphenylbenzotriazole compound as a first screening agent and (b) as a second screening agent, at least one compound comprising at least two benzazolyl functional groups or at least one compound comprising at least one benzodiazolyl functional group. This admixture imparts enhanced sun protection factors to the subject compositions via an unexpected synergistic effect.
2. Description of the Prior Art
It is known to this art that light radiation with wavelengths from 280 nm to 400 nm promotes tanning of the human epidermis and that irradiation of wavelengths of from 280 nm to 320 nm, i.e., UV-B irradiation, causes skin burns and erythema which may be harmful to the development of a natural tan; this UV-B radiation should thus be screened from the skin.
It is also known to this art that UV-A radiation, of wavelengths from 320 to 400 nm, which tans the skin, also adversely affects it, in particular in the case of sensitive skin or of skin which is continually exposed to solar radiation. In particular, UV-A rays cause a loss of elasticity of the skin and the appearance of wrinkles, promoting a premature aging thereof. Such irradiation promotes triggering of the erythemal reaction or amplifies this reaction in certain individuals and may even be the cause of phototoxic or photoallergic reactions. It is thus desirable to also screen out UV-A radiation.
A wide variety of cosmetic compositions for the photoprotection of human skin (against UV-A and/or UV-B) are known to this art.
These sunscreen/antisun compositions are typically in the form of an emulsion of oil-in-water type (i.e., a cosmetically acceptable support comprising an aqueous dispersing continuous phase and an oily dispersed discontinuous phase) which contains, in varying concentrations, one or more conventional lipophilic and/or hydrophilic organic sunscreens capable of selectively absorbing the harmful or deleterious UV radiation, these screening agents (and the amounts thereof) being selected as a function of the desired protection factor (the protection factor (PF) being expressed mathematically by the ratio of the irradiation time required to reach the erythema-forming threshold with the UV screening agent, to the time required to attain the erythema-forming threshold without a UV screening agent).
SUMMARY OF THE INVENTION
It has now surprisingly and unexpectedly been determined that unique intimate admixture, in proportions within well defined limits, of two specific sunscreens per se known to this art provides, via notable synergistic effect, sunscreen/antisun compositions which have markedly improved sun protection factors that are in all instances very much higher than those which can be obtained from either of the screening agents administered alone.
Briefly, the present invention features novel cosmetic compositions, in particular sunscreen/antisun compositions, comprising, formulated into a topically applicable, cosmetically acceptable support therefor, (i) at least one bis-hydroxyphenylbenzotriazole hydrocarbon-based compound, as a first screening agent, and (ii) at least one compound comprising at least two benzazolyl functional groups per molecule and/or at least one compound comprising at least one benzodiazolyl functional group per molecule, as a second screening agent; the said first and second screening agents are present in the subject compositions in proportions which elicit synergistic activity in respect of the sun protection factors imparted.
The present invention also features the use of such compositions for the formulation of cosmetic compositions for protecting the skin and/or the hair against ultraviolet radiation, in particular solar radiation.
DETAILED DESCRIPTION OF BEST MODE AND SPECIFIC/PREFERRED EMBODIMENTS OF THE INVENTION
More particularly according to the present invention, by the expression “comprising at least two benzazolyl functional groups” is intended comprising at least two groups of benzoxazolyl, benzothiazolyl or benzimidazolyl type per molecule.
By the expression “comprising at least one benzodiazolyl functional group” is intended comprising one group of benzodioxazolyl, benzodithiazolyl or benzodiimidazolyl type per molecule.
Exemplary bis-hydroxyphenylbenzotriazole compounds according to the invention include the preferred compounds having the structural formula (1) below:
in which the radicals T
4
and T
5
, which may be identical or different, are each a C
1
-C
18
alkyl radical optionally substituted with one or more radicals selected from among C
1
-C
4
alkyl, C
5
-C
12
cycloalkyl or aryl radicals (such as phenyl or benzyl radicals). Preferably, T
4
and T
5
are simultaneously an &agr;,&agr;-dimethylbenzyl radical. These compounds are known per se and are described in GB-A-2,303,549, DE-197 26 184 and EP-A-893,119, hereby expressly incorporated by reference.
Other preferred bis-hydroxyphenylbenzotriazole compounds according to the invention include those particularly preferred compounds having the structural formula (II) below:
in which the radicals T
6
and T
7
, which may be identical or different, are each a C
1
-C
18
alkyl radical optionally substituted with one or more radicals selected from among C
1
-C
4
alkyl, C
5
-C
12
cycloalkyl or aryl radicals. These compounds are known per se and are described in the aforesaid GB-A-2,303,549, DE-197 26 184 and EP-A-893,119.
Among the compounds of formula (II), those more particularly preferred have the following structures:
In the above formulae (I) and (II):
(i) the C
1
-C
18
alkyl radicals may be linear or branched and include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-amyl, n-hexyl, n-heptyl, n-octyl, isooctyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, tetradecyl, hexadecyl and octadecyl radicals;
(ii) the C
5
-C
12
cycloalkyl radicals include, for example, cyclopentyl, cyclohexyl and cyclooctyl radicals;
(iii) the aryl radicals include, for example, phenyl and benzyl radicals.
The screening agent(s) of the bis-hydroxyphenylbenzotriazole hydrocarbon-based compound type according to the invention are advantageously present in the subject screening compositions in a total concentration ranging from 0.1% to 15% by weight, approximately, and preferably from 0.2% to 10% by weight, approximately, relative to the total weight of the composition.
In one specific embodiment of the invention, the bis-hydroxyphenylbenzotriazole hydrocarbon-based derivatives may be in a specific form and may be insoluble or substantially insoluble in the usual cosmetic solvents (water, alcohols, fatty acids, etc.).
Consistent herewith, by the expression “insoluble or substantially insoluble compounds” are intended compounds whose solubility in water is less than 0. 1% by weight, whose solubility in liquid petroleum jelly is less than 1% by weight and, lastly, whose solubility in a mixture of triglyceride esters such as “Miglyol 812” marketed by Dynamit Nobel is less than 2%, also by weight.
The bis-hydroxyphenylbenzotriazole compounds can be converted to a particular suitable form by any means such as, in particular, dry-grinding or grinding in a solvent medium, screening, atomization, micronization or spraying.
In another specific embodiment of the invention, the bis-hydroxyphenylbenzotriazole compounds can be in insoluble micronized form. The average size of such particles will generally range from 0.01 to 2 &mgr;m, more preferably from 0.02 to 1.5 &mgr;m and more particularly from 0.05 to 1.0 &mgr;m.
The
Burns Doane Swecker & Mathis L.L.P.
Dodson Shelley A.
Societe L'Oreal S.A.
LandOfFree
Photoprotective/cosmetic compositions comprising... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Photoprotective/cosmetic compositions comprising..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Photoprotective/cosmetic compositions comprising... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2605140