Cosmetic/sunscreen compositions containing dibenzoylmethane compounds and dithiolane compound photostabilizers therefor
Cosmetic/sunscreen compositions contain a combination of at least one dibenzoylmethane sunscreen compound and a photostabilizing amount of at least one dithiolane compound of formula (I) below:
1. A topically applicable cosmetic/sunscreen composition comprising at least one UV-screening system which comprises:
(a) at least one dibenzoylmethane compound and a photostabilizing amount of
(b) at least one dithiolane compound of formula (I) below:
in which:
Y is O or NR 1 ;
R 1 is a hydrogen atom, a saturated linear C 1 -C 20 or branched C 3 -C 20 or unsaturated C 2 -C 20 alkyl hydrocarbon-based radical, an aryl radical optionally substituted with one or more hydroxyl groups and/or with one or more C 1 -C 8 alkoxy radicals;
R is a hydrogen atom, a saturated linear C 1 -C 20 or branched C 3 -C 20 or unsaturated C 2 -C 20 alkyl hydrocarbon-based radical, an aryl radical or a saturated C 1 -C 8 alkyl radical containing an aryl substituent optionally substituted with one or more hydroxyl groups and/or with one or more C 1 -C 8 alkoxy radicals;
R optionally bears one or more substituents selected from among OR 2 , SR 2 , NR 2 R 3 and COOR 2 in which:
R 2 is a hydrogen atom or a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based radical, or an aryl radical;
R 3 is a hydrogen atom, a saturated linear C 1 -C 5 or branched C 3 -C 5 or unsaturated C 2 -C 5 hydrocarbon-based radical, an aryl radical, or an acetyl radical;
with the proviso that R and R 1 may together form a ring member selected from among pyrrolidine, pyrroline, piperidine, piperazine, morpholine, thiomorpholine and azepine; and also the salts, chelates, solvates and optical isomers thereof, formulated into a topically applicable, cosmetically/dermatologically acceptable support therefor.
2. The cosmetic/sunscreen composition as defined by claim 1 , in which the compound of formula (I) is selected from among those for which Y is NR 1 and R 1 =H.
3. The cosmetic/sunscreen composition as defined by claim 1 , in which the compound of formula (I) is selected from among those for which R=H or a C 1 -C 8 alkyl radical.
4. The cosmetic/sunscreen composition as defined by claim 1 , in which the compound of formula (I) is selected from among the following compounds:
Chemical
No.
Structure
name
1
4-Methyl-1,2- dithiolane-4- carboxylic acid
2
4-Methyl-1,2- dithiolane-4- carboxamide
3
Methyl 4- methyl-1,2- dithiolane-4- carboxylate
4
Ethyl 4- methyl-1,2- dithiolane-4- carboxylate
5
Propyl 4- methyl-1,2- dithiolane-4- carboxylate
6
Benzyl 4- methyl-1,2- dithiolane-4- carboxylate
7
N-Methyl 4-methyl-1,2- dithiolane-4- carboxamide
8
{[(4-Methyl- 1,2-dithiolan- 4-yl)- carbonyl]- amino}acetic acid
9
Octyl 4- methyl-1,2- dithiolane-4- carboxylate
10
N-Heptyl- 4-methyl-1,2- dithiolane-4- carboxamide
11
N-Butyl- 4-methyl-1,2- dithiolane-4- carboxamide
12
Methyl 2-{[(4-methyl- 1,2-dithiolan- 4-yl)- carbonyl]- amino}-4- (methyl- sulfanyl)- butanoate
13
S-[2-(Acetyl- amino)- ethyl] 4- methyl- 1,2-dithiolane- 4-carbothioate
14
N-(2-Hydroxy- ethyl)-4-methyl- 1,2-dithiolane- 4-carboxamide
15
N-(2,3-Di- hydroxy- propyl)- 4-methyl-1,2- dithiolane-4- carboxamide
16
N-(4- Hydroxy-3- methoxy- benzyl)- 4-methyl-1,2- dithiolane-4- carboxamide
17
N-[2-(4- Hydroxy-3- methoxy- phenyl)- ethyl]-4- methyl-1,2- dithiolane-4- carboxamide
18
N,N-Diethyl- 4-methyl-1,2- dithiolane-4- carboxamide
19
[(4-Methyl- 1,2-dithiolan- 4-yl)- carbonyl]- pyrrolidine
20
4-Methyl-N- (1-methyl- ethyl)-1,2- dithiolane-4- carboxamide
21
4-Methyl-N- phenyl-1,2- dithiolane-4- carboxamide
22
N-[2-(4- Hydroxy- phenyl)- ethyl]-4- methyl-1,2- dithiolane-4- carboxamide
23
N-Propyl-4- methyl-1,2- dithiolane-4- carboxamide
24
N-Pentyl-4- methyl-1,2- dithiolane-4- carboxamide
25
N-Hexyl-4- methyl-1,2- dithiolane-4- carboxamide.
5. The cosmetic/sunscreen composition as defined by claim 4 , in which the compound of formula (I) is selected from among the following compounds:
Chemical
No.
Structure
name
1
4-Methyl-1,2- dithiolane-4- carboxylic acid
2
4-Methyl-1,2- dithiolane-4- carboxamide
9
Octyl 4- methyl-1,2- dithiolane-4- carboxylate
10
N-Heptyl- 4-methyl-1,2- dithiolane-4- carboxamide.
6. The cosmetic/sunscreen composition as defined by claim 1 , in which the dibenzoylmethane derivative is 4-(tert-butyl)-4′-methoxydibenzoylmethane, or Butyl Methoxy Dibenzoylmethane, of the following formula:
7. The cosmetic/sunscreen composition as defined by claim 1 , further comprising other UV-A-active and/or UV-B-active organic or mineral screening agents, which are water-soluble or liposoluble, or insoluble in a cosmetic solvent.
8. The cosmetic/sunscreen composition as defined by claim 7 , in which the other organic screening agents are selected from among anthranilates; cinnamic derivatives; salicylic derivatives; camphor derivatives; benzophenone derivatives; β-,β-diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives; benzimidazole derivatives; imidazolines; bis-benzazolyl derivatives; p-aminobenzoic acid (PABA) derivatives; methylenebis(hydroxyphenylbenzotriazole) derivatives; benzoxazole derivatives; screening polymers and screening silicones; α-alkylstyrene-based dimers; 4,4-diarylbutadienes; merocyanin derivatives; and mixtures thereof.
9. The cosmetic/sunscreen composition as defined by claim 8 , comprising organic UV-screening agent(s) selected from among the following compounds:
Ethylhexyl methoxycinnamate,
Ethylhexyl salicylate,
Homosalate,
Octocrylene,
Phenylbenzimidazolesulfonic acid,
Benzophenone-3,
Benzophenone-4,
Benzophenone-5,
n-Hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate,
4-Methylbenzylidenecamphor,
Terephthalylidenedicamphorsulfonic acid,
Disodium phenyldibenzimidazoletetrasulfonate,
Methylenebis(benzotriazolyl)tetramethylbutylphenol,
Bis(ethylhexyloxyphenol)methoxyphenyltriazine,
Ethylhexyltriazone,
Diethylhexylbutamidotriazone,
2,4bis(4′-aminobenzoate de n-butyle)-6-(aminopropyltrisiloxane)-s-triazine,
2,4,6-Tris(dineopentyl 4′-aminobenzalmalonate)-s-triazine,
2,4,6-Tris(diisobutyl 4′-aminobenzalmalonate)-s-triazine,
2,4-Bis(dineopentyl 4′-aminobenzalmalonate)-6-(n-butyl 4′-aminobenzoate)-s-triazine,
2,4,6-Tris(biphenyl-4-yl)-1,3,5-triazine,
2,4,6-Tris(terphenyl)-1,3,5-triazine,
Drometrizole trisiloxane,
Polysilicone-15,
1,1-Dicarboxy(2,2′-dimethylpropyl)-4,4-diphenylbutadiene,
2,4-Bis[5-1(dimethylpropyl)benzoxazol-2-yl(4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine,
Octyl 5-N,N-diethylamino-2-phenylsulfonyl-2,4-pentadienoate,
and mixtures thereof.
10. The cosmetic/sunscreen composition as defined by claim 7 , comprising mineral screening agents that are coated or uncoated metal oxide pigments.
11. The cosmetic/sunscreen composition as defined by claim 10 , in which the coated or uncoated metal oxide pigments have a mean primary particle size ranging from 5 nm to 100 nm.
12. The cosmetic/sunscreen composition as defined by claim 10 , in which the coated or uncoated metal oxide pigments are selected from the group consisting of titanium oxide, iron oxide, zinc oxide, zirconium oxide and cerium oxide pigments, and mixtures thereof.
13. The cosmetic/sunscreen composition as defined by claim 1 , comprising an oil-in-water or water-in-oil emulsion.
14. A process for improving the chemical stability, with respect to UV radiation, of at least one dibenzoylmethane compound, comprising formulating said at least one dibenzoylmethane compound with a thus effective amount of at least one dithiolane compound of formula (I) as defined in claim 1 .
15. A process of improving the efficacy of at least one dibenzoylmethane compound with respect to UV-A rays, comprising formulating same with at least one dithiolane compound of formula (I) as defined in claim 1 .
16. A regime or regimen for photoprotecting the skin against the damaging effects of UV-radiation, comprising applying thereon a thus effective amount of the cosmetic/sunscreen composition as defined by claim 1 .