Drug – bio-affecting and body treating compositions – Designated organic active ingredient containing – Having -c- – wherein x is chalcogen – bonded directly to...
Reexamination Certificate
2002-05-24
2004-08-24
Solola, Taofiq (Department: 1626)
Drug, bio-affecting and body treating compositions
Designated organic active ingredient containing
Having -c-, wherein x is chalcogen, bonded directly to...
C549S214000
Reexamination Certificate
active
06780888
ABSTRACT:
The present invention relates to novel fat-soluble and stable silicon-containing derivatives of ascorbic acid. The invention also relates in particular to cosmetic and pharmaceutical compositions comprising these novel derivatives, as well as their use.
A number of derivatives of silicon are known. Thus, patent application FR2645863 describes molecular complexes formed of a compound belonging to the silanol family and of an alkali metal or ammonium derivative of an organic or inorganic acid. Molecular combinations are thus obtained which have the advantage of being soluble in water. This document cites in particular the molecular complex formed of a monomethylsilanetriol and of potassium ascorbate. However, as is specified in this document, the stability of these complexes is not very good, in particular when they are in concentrated solution. In particular, they tend to polymerize, which causes their partial insolubilization. A 2,3,5,6-bis(dimethylsilyl)ascorbate or ascorbosilyl is also known from patent application WO96/10575; in this case, it is a precursor of reactive silanol functions and is therefore also unstable.
The aim of the present invention is to provide novel silicon-containing compounds derived from ascorbic acid, the said compounds being fat-soluble and having good stability both in the dry state and in dilute or concentrated solution.
The subject of the invention is therefore novel silicon-containing compounds derived from ascorbic acid, as are defined below.
Another subject of the invention is a method of preparing the compounds of formulae (2) to (4) defined below, by hydrosilylation of the corresponding siloxane or silane derivative represented by one of the formulae (5) to (7) defined below, on an organic derivative of ascorbic acid chosen from the compounds of formula (I′) defined below, followed by deprotection of the compound obtained, for example by acid hydrolysis of the isopropylidenes and/or debenzylation by catalytic hydrogenation.
Another subject of the invention is a method of preparing the silane derivatives of formula (2) defined below by reacting a derivative of formula (I′″), defined below, with a silane derivative of the following formula (8)
in which Hal represents a halogen and more particularly chlorine or iodine and the radicals R
1
, R′
1
, R′
2
. R′
3
, V, p and q have the same meanings as above.
Yet another subject of the invention is an in particular cosmetic or pharmaceutical composition comprising a cosmetically or pharmaceutically acceptable medium and at least one silicon-containing compound derived from ascorbic acid as defined above.
Another subject of the invention is the use of at least one such silicon-containing compound derived from ascorbic acid as antioxidant and/or anti-free-radical agent, in particular in a cosmetic or pharmaceutical composition.
In particular, this use may be cosmetic for, or in a cosmetic composition intended for, treating oxidative stress and/or treating the effects of exposure to sunlight and/or preventing ageing in particular of the skin, the hair, the eyelashes, the eyebrows and/or the nails.
This use may also be for the preparation of a pharmaceutical composition intended for treating oxidative stress and/or treating the effects of exposure to ionizing or solar radiation, and/or preventing ageing in particular of the skin, of the hair, of the eyelashes, of the eyebrows and/or of the nails, and/or treating the effects of the use of certain medicaments which generate free radicals.
Thus, the applicant has found that by covalently grafting one or more ascorbic acid derivatives onto a silicon-containing chain, novel compounds were obtained which had very good properties of solubility in the customary organic solvents, in particular in fatty substances such as oils, as well as high stability in these media or as such.
Moreover, it was observed that these compounds had excellent cosmetic properties.
The compounds according to the invention are therefore characterized in that
either they consist of a silicone-containing chain comprising at least one unit of formula (1):
or they are silanes corresponding to the following formula (2):
A—SiR′
1
R′
2
R′
3
(2)
in which:
R denotes a linear, cyclic or branched, saturated or unsaturated, optionally partially or completely halogenated, C
1
-C
30
hydrocarbon radical or a trimethylsilyloxy group of formula —O—SiMe
3
;
a is equal to 1 or 2,
R′
1
, R′
2
, R′
3
, which are identical or different, are chosen from linear or branched C
1
-C
8
alkyl radicals, linear or branched C
1
-C
8
alkenyl radicals, or a trimethylsilyloxy group;
A is a radical of the following formula (I):
in which L
1
, L
2
, L
3
and L
4
represent hydrogen or a divalent radical of formula (a) or (a′) allowing the attachment of the radical A onto the silicon-containing chain, with the proviso that at least one of the radicals L
1
, L
2
, L
3
and L
4
, preferably only one of the said radicals L
1
, L
2
, L
3
and L
4
, represents the said divalent radical of the following formula (a) or (a′):
in which:
V is a linear or branched, saturated or unsaturated, divalent C
1
-C
6
hydrocarbon radical optionally substituted with a hydroxyl radical or a linear or branched, saturated or unsaturated C
2
-C
8
alkoxy radical;
R
1
represents a hydrogen atom, a hydroxyl radical or a linear or branched, saturated or unsaturated C
1
-C
8
hydrocarbon radical;
p is 0 or 1, q is 0 or 1, it being understood that p+q is different from 0.
The compounds according to the invention consisting of a silicone-containing chain comprising at least one unit of formula (1) above therefore comprise in particular at least one unit of formula (1a):
and/or at least one unit of formula (1b):
Preferably, they may comprise in addition at least one other unit, for example of the (di-)alkylsiloxane type of formula (1c):
Thus, they may in particular be represented by one of the following formulae (3) or (4):
in which:
the radicals B, which are identical or different, are chosen from the radicals R and A,
r is an integer between 0 and 50 inclusive, preferably between 0 and 5,
s is an integer between 0 and 20 inclusive, preferably chosen from 0, 1 or 2, with the proviso that if s=0, then at least one of the two radicals B represents A,
u is an integer between 1 and 6 inclusive, preferably chosen from 1 or 2,
t is an integer between 0 and 9 inclusive, preferably chosen from 2, 3 or 4,
it being understood that t+u is between 3 and 10 inclusive, and is preferably equal to 3, 4, 5 or 6.
Preferably, the radicals R, which are identical or different, are chosen from linear, cyclic or branched, saturated or unsaturated C
1
-C
18
hydrocarbon radicals and linear or branched, saturated or unsaturated, partially halogenated, in particular fluorinated, C
1
-C
8
hydrocarbon radicals.
Still more preferably, the radicals R, which are identical or different, are chosen from linear or branched C
1
-C
10
alkyl radicals, the phenyl radical and the linear or branched fluorinated C
1
-C
8
alkyl radicals.
The methyl and 3,3,3-trifluoropropyl radicals may be mentioned in particular. More particularly, at least 80% in numerical terms of the radicals R are methyl radicals.
Preferably, the radicals R′
1
, R′
2
, R′
3
, which are identical or different, are chosen from linear or branched C
1
-C
6
alkyl radicals, in particular methyl or ethyl radicals, and the trimethylsilyloxy group.
In general, the silicon-containing derivatives corresponding to one of the formulae (1), (2), (3) or (4), and having at least one of the following characteristics will be more particularly preferred:
R is CH
3
;
B is CH
3
;
R′
1
, R′
2
, R′
3
represent CH
3
or the trimethylsilyloxy group;
R
1
is hydrogen or CH
3
;
V is —CH
2
— or —CH
2
—CH(OH)CH
2
—;
p is 1,
r is between 0 and 5 inclusive,
s is between 1 and 2 inclusive,
t+u is between 3 and 6.
Preferably, the divalent radicals corresponding to the formulae (a) or (
Richard Herve
Xu Jinzhu
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
L'Oreal (S.A.)
Solola Taofiq
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