U.S. patent application number 10/305115 was filed with the patent office on 2003-07-17 for use of a composition containing at least one oxidation-sensitive hydrophilic active principle and at least one n-vinylmidazole polymer or copolymer.
This patent application is currently assigned to L'OREAL. Invention is credited to Biatry, Bruno, Lheureux, Eric.
Application Number | 20030133889 10/305115 |
Document ID | / |
Family ID | 8869872 |
Filed Date | 2003-07-17 |
United States Patent
Application |
20030133889 |
Kind Code |
A1 |
Biatry, Bruno ; et
al. |
July 17, 2003 |
Use of a composition containing at least one oxidation-sensitive
hydrophilic active principle and at least one N-vinylmidazole
polymer or copolymer
Abstract
The invention relates to the use of a composition containing, in
a physiologically acceptable medium having an aqueous phase, at
least one oxidation-sensitive hydrophilic active principle selected
from the group consisting of ascorbic acid and its derivatives and
at least one non-crosslinked N-vinylimidazole polymer or copolymer,
the active principle and the polymer or copolymer both being in the
aqueous phase, for preventing or combatting the harmful effects of
UV radiation and/or of pollution on the skin, in particular loss of
firmness and/or of elasticity of the skin.
Inventors: |
Biatry, Bruno; (Vincennes,
FR) ; Lheureux, Eric; (Montgerno, FR) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
L'OREAL
Paris
FR
|
Family ID: |
8869872 |
Appl. No.: |
10/305115 |
Filed: |
November 27, 2002 |
Current U.S.
Class: |
424/59 ; 424/401;
424/486 |
Current CPC
Class: |
A61Q 19/08 20130101;
A61K 2800/522 20130101; A61Q 19/02 20130101; A61Q 5/08 20130101;
A61P 17/16 20180101; A61P 17/00 20180101; A61K 8/676 20130101; A61K
8/817 20130101; A61P 43/00 20180101 |
Class at
Publication: |
424/59 ; 424/401;
424/486 |
International
Class: |
A61K 007/42; A61K
009/14; A61K 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2001 |
FR |
0115375 |
Claims
1. A method for treating skin and/or mucous membrane, comprising
applying to skin or mucous membrane a composition comprising, in a
physiologically acceptable medium comprising an aqueous phase, at
least one oxidation-sensitive hydrophilic active principle selected
from the group consisting of ascorbic acid and its derivatives and
at least one non-crosslinked N-vinylimidazole polymer or copolymer,
the at least one active principle and the at least one polymer or
copolymer both being present in the aqueous phase.
2. The method of claim 1, wherein said treating is selected from
the group consisting of preventing or combatting harmful effects of
UV radiation and/or of pollution, preventing or combatting loss of
firmness and/or of elasticity, combatting free radicals, and
soothing sunburn, said method comprising applying an amount of said
composition to skin and/or mucous membrane to so treat.
3. The method of claim 2, wherein said treating is preventing or
combatting harmful effects of UV radiation and/or of pollution.
4. The method of claim 2, wherein said treating is preventing or
combatting loss of firmness and/or of elasticity.
5. The method of claim 2, wherein said treating is combatting free
radicals.
6. The method of claim 2, wherein said treating is soothing
sunburn.
7. The method according to claim 1, wherein the ascorbic acid
derivatives are selected from the group consisting of ascorbic acid
esters and ascorbic acid salts.
8. The method according to claim 1, wherein the hydrophilic active
principle is selected from the group consisting of
5,6-di-O-dimethylsilylascorbate, dl-.alpha.-tocopheryl dl-ascorbyl
phosphate potassium salt, magnesium ascorbyl phosphate and sodium
ascorbyl phosphate.
9. The method according to claim 1, wherein the oxidation-sensitive
hydrophilic active principle is ascorbic acid.
10. The method according to claim 1, wherein the composition
comprises a non-crosslinked copolymer that is a combination of the
N-vinylimidazole with N-vinylpyrrolidone and/or N-vinylcaprolactam
subunits.
11. The method according to claim 1, wherein the composition
comprises a non-crosslinked copolymer that is an
N-vinylimidazole/N-vinylpyrrolidone copolymer.
12. The method according to claim 1, wherein the composition
comprises a non-crosslinked copolymer that is selected from the
group consisting of a vinylpyrrolidone/vinylimidazole (50/50)
copolymer having a weight-average molar mass of 1 200 000 and a
vinylpyrrolidone/vinylimidazole (50/50) copolymer having a
weight-average molar mass of 10 000.
13. The method according to claim 1, wherein a molar ratio of
N-vinylimidazole unit equivalent to the oxidation-sensitive
hydrophilic active principle is from 0.004 to 16.
14. The method according to claim 13, wherein the molar ratio of
the N-vinylimidazole unit equivalent to the oxidation-sensitive
hydrophilic active principle varies between 0.01 and 1.
15. The method according to claim 1, wherein the polymer or
copolymer is present at a concentration of 0.1 to 5% by weight of
the aqueous phase.
16. The method according to claim 13, wherein the polymer or
copolymer is present at a concentration of 0.1 to 2% by weight of
the aqueous phase.
17. The method according to claim 1, wherein the polymer or
copolymer has a molar fraction of N-vinylimidazole units of 0.1 to
1.
18. The method according to claim 15, wherein the polymer or
copolymer has a molar fraction of N-vinylimidazole units of 0.4 to
0.9.
19. The method according to claim 1, wherein the composition
further comprises an agent in addition to the hydrophilic active
principle selected from the group consisting of scavengers for
ozone, scavengers for heavy metals and agents for combatting free
radicals.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to the use of a composition
comprising at least one oxidation-sensitive hydrophilic active
principle and at least one N-vinylimidazole polymer or copolymer in
a physiologically acceptable medium comprising an aqueous phase.
Preferably the use is cosmetic or dermatological, and preferably
relates to treating the skin and/or mucous membranes against UV,
pollution, free radicals, and sunburn.
BACKGROUND OF THE INVENTION
[0002] It is known to introduce, into cosmetic compositions,
various active principles intended to contribute specific
treatments to the skin and/or hair. However, some of these active
principles exhibit the disadvantage of being unstable in an aqueous
medium and of easily decomposing on contact with water, in
particular because of oxidation phenomena. They thus rapidly lose
their activity over time and this instability conflicts with the
desired effectiveness.
[0003] Attempts have thus been made for a long time to formulate
ascorbic acid or vitamin C because of its numerous beneficial
properties. In particular, ascorbic acid stimulates the synthesis
of the connective tissue and in particular of collagen, strengthens
the defences of the cutaneous tissue against external attacks, such
as ultraviolet radiation and pollution, compensates for vitamin E
deficiency of the skin, depigments the skin and has a role in
combatting free radicals. These last two properties make it an
excellent candidate as cosmetic or dermatological active principle
for combatting ageing of the skin or for preventing ageing of the
skin. Unfortunately, because of its chemical structure (of
.alpha.-ketolactone), ascorbic acid is highly sensitive to certain
environmental parameters and in particular to oxidation phenomena.
There thus ensues rapid decomposition of formulated ascorbic acid
in the presence of these parameters and in particular in the
presence of oxygen, light or metal ions, as a function of the
temperature or under certain pH conditions (Pharm. Acta. Helv.,
1969, 44, 611-667; STP Pharma, 1985, 4, 281-286).
[0004] Several solutions have thus been envisaged in the prior art
for reducing and/or slowing down the decomposition of ascorbic
acid.
[0005] Provision has thus been made to use ascorbic acid in the
form of a chemical derivative (magnesium ascorbyl phosphate or
esters of fatty acids and ascorbic acid), but the bioavailability
of these derivatives is very low (J. Am. Acad. Dermatol., 1996, 34,
29-33).
[0006] The instability of ascorbic acid with respect to oxygen can
be improved by using specific packagings, such as twin compartments
under an inert atmosphere, as disclosed in U.S. Pat. No. 5,935,584,
or alternatively by the use of two-phase emulsions, one phase of
which is composed of a dry powder comprising ascorbic acid and the
second phase of which is a liquid phase. The mixing of the two
phases has to be carried out at the time of use (WO 98/43598).
These solutions have disadvantages with regard to the cost and the
complexity of the manufacturing operations and significant
restrictions with regard to use.
[0007] Another solution provided in the prior art consists in using
a high concentration of glycols or polyols in order to reduce the
solubility of oxygen in the formulation, thus protecting the
ascorbic acid (WO 96/24325, EP 0 755 674, U.S. Pat. No. 5,981,578).
The polyols can optionally be incorporated in liposomes, as
disclosed in U.S. Pat. No. 6,020,367. However, these solutions
exhibit the disadvantage of resulting in sticky formulations, the
cosmetic quality of which is difficult to improve. Furthermore, the
presence of a high concentration of these compounds can lead to
phenomena of irritation.
[0008] Ascorbic acid can also be formulated in anhydrous media,
such as silicones (U.S. Pat. No. 6,194,452), which are capable of
creating an anhydrous barrier around ascorbic acid. A major
disadvantage of such solutions results from the lack of freshness
on application.
[0009] The need thus remains for a composition employable in
particular in the cosmetics field, in which a hydrophilic active
principle which is unstable in an oxidizing medium is stabilized,
which is comfortable on application, which does not lead to any
skin irritation after application and which is compatible with the
constraints of an industrial implementation of its manufacturing
process.
[0010] Cutaneous ageing of physiological nature can be accelerated
by environmental factors, such as repeated exposure of the skin to
sunlight, in particular to ultraviolet A radiation, or to
pollution, in particular to diesel particles or to cigarette smoke.
The action of the environment on the constituents of the skin
(fibres, cells, enzymes) and on the sebum secreted by the skin
results in particular in the formation of oxygen free radicals. In
point of fact, these radicals result in significant oxidative
damage, in particular in cell membranes (permeability of the
membranes), cell nuclei (destruction of DNA), and tissues, in
particular connective tissue (decomposition of elastin and collagen
fibres). This damage results in particular in the loss of firmness
and elasticity of the skin.
[0011] Ascorbic acid, by trapping free radicals, protects
biological molecules. Thus, applied topically, it can accumulate in
the skin and can restore the disrupted concentration of ascorbic
acid, for example in the case of exposure to UV radiation. It can,
moreover, protect the skin from damage induced by UV radiation
(British Journal of Dermatology, 127, 1992, p. 247-253) or by
environmental stress.
[0012] In parallel with this activity, ascorbic acid has an
inhibitory effect on the secretion of the pro-inflammatory
cytokines IL1 and IL6 induced by UV radiation (Journal of
Investigative Dermatology, 108(3), 1997, p. 302-308). It is
therefore of particular advantage as soothing agent for
sunburn.
OBJECTS OF THE INVENTION
[0013] One object of the present invention is to provide a
composition comprising an oxidation-sensitive active principle
selected from the group consisting of ascorbic acid and its
derivatives, which exhibits good cosmetic properties, both with
regard to touch and with regard to tolerance, the preservation of
which over time does not require specific precautions, and which
retains the activity in combatting free radicals of the said active
principle, for preventing or combatting the harmful effects of UV
radiation and/or of pollution on the skin, in particular the loss
of firmness and/or of elasticity of the skin.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The inventors have discovered that the use of
non-crosslinked N-vinylimidazole polymers or copolymers in
compositions in which the aqueous phase includes an
oxidation-sensitive active principle, such as ascorbic acid or one
of its derivatives, makes it possible to achieve the abovementioned
object.
[0015] In the prior art, some compounds having an imidazole
structure have been disclosed for their stabilizing properties.
Thus, in Patent Application EP 0 586 106, several imidazole-based
molecules are used to stabilize certain retinoids against chemical
decomposition. Furthermore, polymeric emulsifiers composed of
N-vinylimidazole, of alkyl acrylates and of vinyl acetates are
disclosed in U.S. Pat. No. 4,057,622. They are used for the purpose
of replacing known emulsifiers in order to overcome their
disadvantages, in particular with regard to smell, and to stabilize
water-in-oil emulsions. Finally,
N-vinylimidazole/N-vinylcaprolactam/N-vi- nylpyrrolidone copolymers
are disclosed in U.S. Pat. No. 6,191,188. They are used in the
manufacture of hair-strengthening compositions.
[0016] To the knowledge of the inventors, polymers or copolymers
comprising N-vinylimidazole units have never been used in
combination with hydrophilic active principles sensitive to
decomposition by oxidation for the purpose of improving their
stability in an aqueous medium. This is true in particular in the
case of ascorbic acid.
[0017] One embodiment of the present invention is therefore the
cosmetic and/or dermatological use, for preventing or combatting
the harmful effects of UV radiation and/or of pollution on the
skin, of a composition comprising, in a physiologically acceptable
medium comprising an aqueous phase, at least one
oxidation-sensitive hydrophilic active principle selected from the
group consisting of ascorbic acid and its derivatives and at least
one non-crosslinked N-vinylimidazole polymer or copolymer, the said
active principle and the said polymer or copolymer both being in
the aqueous phase. The copolymer is present in an amount sufficient
to stabilize the said oxidation-sensitive hydrophilic active
principle.
[0018] Another embodiment of matter of the present invention is the
preferably cosmetic and/or dermatological use, for preventing or
combatting loss of firmness and/or of elasticity of the skin, of a
composition comprising, in a physiologically acceptable medium
comprising an aqueous phase, at least one oxidation-sensitive
hydrophilic active principle selected from the group consisting of
ascorbic acid and its derivatives and at least one non-crosslinked
N-vinylimidazole polymer or copolymer, the active principle and the
polymer or copolymer both being in the aqueous phase.
[0019] Another embodiment of the present invention is the use of a
combination composed of at least one oxidation-sensitive
hydrophilic active principle selected from the group consisting of
ascorbic acid and its derivatives and of at least one
non-crosslinked N-vinylimidazole polymer or copolymer in the
aqueous phase of a composition as agent for combatting free
radicals.
[0020] Another embodiment of the present invention is the use of a
combination composed of at least one oxidation-sensitive
hydrophilic active principle selected from the group consisting of
ascorbic acid and its derivatives and of at least one
non-crosslinked N-vinylimidazole polymer or copolymer in the
aqueous phase of a composition as soothing agent for sunburn.
[0021] The term "pollution" as used herein is understood to mean
both "external" pollution, for example due to diesel particles, to
ozone or to heavy metals, an "internal" pollution, which can in
particular be due to emissions of solvents from paints, from fitted
carpet adhesives, from insulation or from wallpaper (such as
toluene, styrene, xylene or benzaldehyde), or to cigarette smoke.
This is because all these pollutants are capable, directly or
indirectly, of generating free radicals.
[0022] According to the invention, the term "hydrophilic active
principle" is understood to mean a compound having a solubility in
water of at least 0.25% at ambient temperature (25.degree. C.).
[0023] According to the invention, the term "oxidation-sensitive
hydrophilic active principle" is understood to mean any active
principle of natural or synthetic origin capable of undergoing
decomposition by an oxidation mechanism. This oxidation phenomenon
can have several causes, in particular the presence of oxygen, of
light or of metal ions, a high temperature or certain pH
conditions. Preferably the active principle combats free radicals,
and/or UV radiation or the effects thereof, and/or pollution,
and/or sunburn, and/or loss of firmness and/or elasticity.
[0024] Mention may be made, by way of example and without implied
limitation, of: ascorbic acid and its derivatives, such as salts or
esters thereof, particularly the 5,6-di-O-dimethylsilylascorbate
(sold by Exsymol under the reference PRO-AA), the potassium salt of
dl-.alpha.-tocopheryl dl-ascorbyl phosphate (sold by Senju
Pharmaceutical under the reference SEPIVITAL EPC), magnesium
ascorbyl phosphate or sodium ascorbyl phosphate (sold by Roche
under the reference Stay-C 50). Such principles may be present in
any amount, preferably an amount sufficient to effect its purpose,
such as for example 0.5, 1, 5, 25, etc. grams per 100 grams of
composition.
[0025] In a particularly advantageous aspect, the
oxidation-sensitive hydrophilic active principle is ascorbic
acid.
[0026] According to the invention, the term "non-crosslinked
N-vinylimidazole polymer or copolymer" is understood to mean any
polymer comprising N-vinylimidazole units and not comprising a
crosslinking agent. Copolymers suitable for the implementation of
the invention are copolymers combining N-vinylimidazole with
N-vinylpyrrolidone and/or N-vinylcaprolactam subunits.
[0027] In an advantageous aspect of the invention, the copolymer
has a molar fraction of N-vinylimidazole units of between 0.1 and
1, more preferably between 0.4 and 0.9, inclusive.
[0028] According to an advantageous aspect of the invention, the
molar ratio of the N-vinylimidazole unit equivalent to the
oxidation-sensitive hydrophilic active principle varies between
0.004 and 16 and preferably between 0.01 and 1, inclusive.
[0029] Use will preferably be made of an
N-vinylimidazole/N-vinylpyrrolido- ne copolymer.
[0030] The weight-average molar mass of the N-vinylimidazole
polymers will advantageously be between 1 000 and 1.times.10.sup.7
and preferably between 5 000 and 5.times.10.sup.6.
[0031] Use may be made, to this end, of the
vinylpyrrolidone/vinylimidazol- e (50/50) copolymer having a
weight-average molar mass of 1 200 000 sold under the reference
LUVITEC VPI 55K72W by BASF or the vinylpyrrolidone/vinylimidazole
(50/50) copolymer having a weight-average molar mass of 10 000 sold
under the reference LUVITEC VPI 55K18P by BASF.
[0032] The at least one polymer or copolymer is preferably present
in the composition according to the invention in an amount
sufficient to produce the desired effect, that is to say in an
amount sufficient to stabilize the oxidation-sensitive hydrophilic
active principle. Preferably, the copolymer is present at a
concentration of between 0.1 and 5% by weight with respect to the
total weight of the aqueous phase and more particularly at a
concentration of between 0.1 and 2% by weight with respect to the
total weight of the aqueous phase, inclusive. A preferred amount is
a stabilizing amount, that is, an amount that slows or prevents the
oxidation of the active principle, for example at 45.degree. C. for
two months.
[0033] The compositions used according to the invention are
intended in one embodiment for topical application to the skin
and/or its superficial body growths and therefore preferably
comprise a physiologically acceptable medium, that is to say a
medium compatible with cutaneous tissues, such as the skin, scalp,
eyelashes, eyebrows, hair, nails and mucous membranes. This
physiologically acceptable medium comprises an aqueous phase and
optionally a physiologically acceptable organic solvent chosen, for
example, from lower alcohols comprising from 1 to 8 carbon atoms
and in particular from 1 to 6 carbon atoms, such as ethanol,
isopropanol, propanol or butanol; polyethylene glycols having from
6 to 80 ethylene oxide units; or polyols, such as propylene glycol,
isoprene glycol, butylene glycol, glycerol or sorbitol.
[0034] When the physiologically acceptable medium is an aqueous
medium, it may have a pH which is compatible with the skin,
preferably ranging from 3 to 9 and better still from 3.5 to
7.5.
[0035] The compositions according to the invention can be provided
in any form, including any pharmaceutical dosage form used
conventionally for topical application and in particular in the
form of aqueous or aqueous/alcoholic solutions, of oil-in-water
(O/W) or water-in-oil (W/O) or multiple (triple: W/O/W or O/W/O)
emulsions, of aqueous gels or of dispersions of a fatty phase in an
aqueous phase using spherules, it being possible for these
spherules to be polymeric nanoparticles, such as nanospheres and
nanocapsules, or lipid vesicles of ionic and/or nonionic type
(liposomes, niosomes or oleosomes). These compositions are prepared
according to the usual methods.
[0036] In addition, the compositions used according to the
invention can be more or less fluid and can have the appearance of
a white or coloured cream, of an ointment, of a milk, of a lotion,
of a serum, of a paste or of a foam. They can optionally be applied
to the skin in the form of an aerosol. They can also be provided in
a solid form, for example in the form of a stick.
[0037] When the compositions according to the invention comprise an
oily phase, the latter preferably comprises at least one oil. It
can additionally comprise other fatty substances.
[0038] Mention may be made, as oils which can be used in the
composition of the invention, of, for example:
[0039] hydrocarbonaceous oils of animal origin, such as
perhydrosqualene;
[0040] hydrocarbonaceous oils of vegetable origin, such as liquid
triglycerides of fatty acids comprising from 4 to 10 carbon atoms,
such as triglycerides of heptanoic acid or octanoic acid, or
alternatively, for example, sunflower, maize, soybean, gourd, grape
seed, sesame, hazelnut, apricot, macadamia, arara, castor or
avocado oils, triglycerides of caprylic/capric acids, such as those
sold by Starineries Dubois or those sold under the names Miglyol
810, 812 and 818 by Dynamit Nobel, jojoba oil, or karite butter
oil;
[0041] synthetic esters and ethers, in particular of fatty acids,
such as the oils of formulae R.sup.1COOR.sup.2 and R.sup.1OR.sup.2
in which R.sup.1 represents the residue of a fatty acid comprising
from 8 to 29 carbon atoms and R.sup.2 represents a branched or
unbranched hydrocarbonaceous chain comprising from 3 to 30 carbon
atoms, such as, for example, purcellin oil, isononyl isononanoate,
isopropyl myristate, 2-ethylhexyl palmitate, 2-octyldodecyl
stearate, 2-octyldodecyl erucate or isostearyl isostearate;
hydroxylated esters, such as isostearyl lactate, octyl
hydroxystearate, octyldodecyl hydroxystearate, diisostearyl malate,
triisocetyl citrate or heptanoates, octanoates or decanoates of
fatty alcohols; polyol esters, such as propylene glycol
dioctanoate, neopentyl glycol diheptanoate and diethylene glycol
diisononanoate; and pentaerythritol esters, such as pentaerythrityl
tetraisostearate;
[0042] linear or branched hydrocarbons of mineral or synthetic
origin, such as volatile or nonvolatile liquid paraffins and their
derivatives, liquid petrolatum, polydecenes or hydrogenated
polyisobutene, such as parleam oil;
[0043] fatty alcohols having from 8 to 26 carbon atoms, such as
cetyl alcohol, stearyl alcohol and their mixture (cetearyl
alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol,
2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol;
[0044] partially hydrocarbon-comprising and/or silicone-comprising
fluorinated oils, such as those disclosed in the document
JP-A-2-295912;
[0045] silicone oils, such as volatile or nonvolatile
polymethylsiloxanes (PDMS) comprising a linear or cyclic silicone
chain which are liquid or pasty at ambient temperature, in
particular cyclopolydimethylsiloxanes (cyclomethicones), such as
cyclohexasiloxane; polydimethylsiloxanes comprising pendent alkyl,
alkoxy or phenyl groups or alkyl, alkoxy or phenyl groups at the
end of the silicone chain, which groups have from 2 to 24 carbon
atoms; or phenylated silicones, such as phenyl trimethicones,
phenyl dimethicones, phenyltrimethyl-siloxydiphenylsiloxan- es,
diphenyl dimethicones, diphenylmethyldiphenyltrisiloxanes,
(2-phenylethyl)trimethylsiloxysilicates and
polymethylphenylsiloxanes;
[0046] their mixtures.
[0047] The term "hydrocarbonaceous oil" is understood to mean, in
the list of the oils mentioned above, any oil predominantly
comprising carbon and hydrogen atoms and optionally ester, ether,
fluorinated, carboxylic acid and/or alcohol groups.
[0048] The other fatty substances which can be present in the oily
phase are, for example, fatty acids comprising from 8 to 30 carbon
atoms, such as stearic acid, lauric acid, palmitic acid and oleic
acid; waxes, such as lanolin, beeswax, carnauba or candelilla wax,
paraffin or lignite waxes or microcrystalline waxes, ceresin or
ozokerite, or synthetic waxes, such as polyethylene waxes or
Fischer-Tropsch waxes; silicone resins, such as trifluoromethyl
C.sub.1-4 alkyl dimethicone and trifluoropropyl dimethicone; and
silicone elastomers, such as the products sold under the names
"KSG" by Shin-Etsu, under the names "Trefil", "BY29" or "EPSX" by
Dow Coming or under the names "Gransil" by Grant Industries.
[0049] These fatty substances can be chosen in a way varied by a
person skilled in the art in order to prepare a composition having
the desired properties, for example of consistency or of
texture.
[0050] According to a specific embodiment of the invention, the
composition according to the invention is a water-in-oil (W/O) or
oil-in-water (O/W) emulsion. The proportion of the oily phase in
the emulsion can range from 5 to 80% by weight and preferably from
5 to 50% by weight with respect to the total weight of the
composition.
[0051] The emulsions generally comprise at least one emulsifier
selected from the group consisting of amphoteric, anionic, cationic
or nonionic emulsifiers, used alone or as a mixture, and optionally
a coemulsifier. The emulsifiers are appropriately chosen according
to the emulsion to be obtained (W/O or O/W). The emulsifier and the
coemulsifier are generally present in the composition in a
proportion ranging from 0.3 to 30% by weight and preferably from
0.5 to 20% by weight with respect to the total weight of the
composition.
[0052] Mention may be made, for the W/O emulsions, for example, as
emulsifiers, of dimethicone copolyols, such as the mixture of
cyclomethicone and of dimethicone copolyol sold under the name "DC
5225 C" by Dow Corning, and alkyl dimethicone copolyols, such as
the laurylmethicone copolyol sold under the name "Dow Corning 5200
Formulation Aid" by Dow Corning and the cetyl dimethicone copolyol
sold under the name Abil EM 90.sup.R by Goldschmidt. Use may also
be made, as surfactant of W/O emulsions, of a crosslinked solid
organopolysiloxane elastomer comprising at least one oxyalkylenated
group, such as those obtained according to the procedure of
Examples 3, 4 and 8 of the document U.S. Pat. No. 5,412,004 and the
examples of the document U.S. Pat. No. 5,811,487, in particular the
product of Example 3 (synthetic example) of U.S. Pat. No.
5,412,004, and such as that sold under the reference KSG 21 by Shin
Etsu. Use may also be made, as emulsifier, of a polyolefin-derived
oligomer or polymer comprising a succinic ending; the latter is
preferably a polyolefin comprising an esterified or amidated
succinic ending or a salt of such a polyolefin and in particular
polyisobutylene comprising an esterified or amidated succinic
ending such as the products sold under the names L5603 and L2721
and OS131769 by Lubrizol.
[0053] Mention may be made, for the O/W emulsions, for example, as
emulsifiers, of nonionic emulsifiers, such as esters of fatty acids
and of glycerol which are oxyalkylenated (more particularly
polyoxyethylenated); esters of fatty acids and of sorbitan which
are oxyalkylenated; esters of fatty acids which are oxyalkylenated
(oxyethylenated and/or oxypropylenated); ethers of fatty alcohols
which are oxyethylenated (oxyethylenated and/or oxypropylenated);
sugar esters, such as sucrose stearate; and their mixtures, such as
the mixture of glyceryl stearate and of PEG-40 stearate.
[0054] The compositions of the invention can also comprise
adjuvants conventional in the cosmetics or dermatological field,
such as hydrophilic or lipophilic gelling agents, preservatives,
solvents, fragrances, fillers, UV screening agents, bactericides,
odour absorbers, colouring materials, plant extracts or salts. The
amounts of these various adjuvants are those generally used in the
field under consideration, for example from 0.01 to 20% of the
total weight of the composition. These adjuvants, depending on
their nature, can be introduced into the fatty phase, into the
aqueous phase and/or into the lipid spherules.
[0055] Mention may be made, as fillers which can be used in the
composition of the invention, for example, of pigments, silica
powder; talc; particles of polyamide and in particular those sold
under the name Orgasol by Atochem; polyethylene powders;
microspheres based on acrylic copolymers, such as those made of
ethylene glycol dimethacrylate/lauryl methacrylate copolymer which
are sold by Dow Coming under the name Polytrap; expanded powders,
such as hollow microspheres and in particular the microspheres sold
under the name Expancel by Kemanord Plast or under the name
Micropearl F 80 ED by Matsumoto; silicone resin microbeads, such as
those sold under the name Tospearl by Toshiba Silicone; and their
mixtures. These fillers can be present in amounts ranging from 0 to
20% by weight and preferably from 1 to 10% by weight with respect
to the total weight of the composition.
[0056] According to a preferred embodiment, the compositions in
accordance with the invention can additionally comprise at least
one organic photoprotective agent and/or at least one inorganic
photoprotective agent distinct from the above active principle
which is active in the UV-A and/or UV-B regions (absorbers), and
which are soluble in water or in fats or else are insoluble in the
cosmetic solvents commonly used.
[0057] The organic photoprotective agents are not limited and may
be chosen in particular from anthranilates; cinnamic derivatives;
dibenzoylmethane derivatives; salicylic derivatives; camphor
derivatives; triazine derivatives, such as those disclosed in
Patent Applications U.S. Pat. No. 4,367,390, EP 863 145, EP 517
104, EP 570 838, EP 796 851, EP 775 698, EP 878 469, EP 933 376, EP
507 691, EP 507 692, EP 790 243 and EP 944 624; benzophenone
derivatives; -diphenylacrylate derivatives; benzotriazole
derivatives; benzalmalonate derivatives; benzimidazole derivatives;
imidazolines; bisbenzoazolyl derivatives as disclosed in Patents EP
669 323 and U.S. Pat. No. 2,463,264; p-aminobenzoic acid (PABA)
derivatives; methylenebis(hydroxyphenylbenzotriazole) derivatives
as disclosed in Applications U.S. Pat. No. 5,237,071, U.S. Pat. No.
5,166,355, GB 2 303 549, DE 197 26 184 and EP 893 119; screening
polymers and screening silicones, such as those disclosed in
particular in Application WO 93/04665; dimers derived from
-alkylstyrene, such as those disclosed in Patent Application DE 198
55 649; 4,4-diarylbutadienes as disclosed in Applications EP 0 967
200, DE 197 46 654, DE 197 55 649, EP-A-1 008 586, EP 1 133 980 and
EP 133 981; and their mixtures.
[0058] By way of illustration, mention may be made, as
photoprotective agents which are active in the UV-A and/or UV-B
regions, denoted below under their INCI names, of:
[0059] p-aminobenzoic acid (PABA) derivatives, in particular PABA,
ethyl PABA, ethyl dihydroxypropyl PABA, ethylhexyl dimethyl PABA
(sold in particular under the name "Escalol 507" by ISP), glyceryl
PABA or PEG-25 PABA (sold under the name "Uvinul P25" by BASF),
[0060] salicylic derivatives, in particular homosalate (sold under
the name "Eusolex HMS" by Rona/EM Industries), ethylhexyl
salicylate (sold under the name "Neo Heliopan OS" by Haarmann and
Reimeri), dipropylene glycol salicylate (sold under the name
"Dipsal" by Scher), or TEA salicylate (sold under the name "Neo
Heliopan TS" by Haarmann and Reimer),
[0061] dibenzoylmethane derivatives, in particular butyl
methoxydibenzoylmethane (sold in particular under the trade name
"Parsol 1789" by Hoffmann-LaRoche), or isopropyl
dibenzoylmethane,
[0062] cinnamic derivatives, in particular ethylhexyl
methoxycinnamate (sold in particular under the trade name "Parsol
MCX" by Hoffmann-LaRoche), isopropyl methoxycinnamate, isoamyl
methoxycinnamate (sold under the trade name "Neo Heliopan E 1000"
by Haarmann and Reimer), cinoxate, DEA methoxycinnamate,
diisopropyl methyl cinnamate, or glyceryl ethylhexanoate
dimethoxycinnamate,
[0063] , -diphenylacrylate derivatives, in particular octocrylene
(sold in particular under the trade name "Uvinul N539" by BASF) or
etocrylene (sold in particular under the trade name "Uvinul N35" by
BASF),
[0064] benzophenone, in particular benzophenone-1 (sold under the
trade name "Uvinul 400" by BASF), benzophenone-2 (sold under the
trade name "Uvinul D50" by BASF), benzophenone-3 or oxybenzone
(sold under the trade name "Uvinul M40" by BASF), benzophenone-4
(sold under the trade name "Uvinul MS40" by BASF), benzophenone-5,
benzophenone-6 (sold under the trade name "Helisorb 11" by
Norquay), benzophenone-8 (sold under the trade name "Spectra-Sorb
UV-24" by American Cyanamid), benzophenone-9 (sold under the trade
name "Uvinul DS-49" by BASF), benzophenone-12, or n-hexyl
2-(4-diethylamino-2-hydroxybenzoyl)benzoate,
[0065] benzylidene camphor derivatives, in particular 3-benzylidene
camphor (manufactured under the name "Mexoryl SD" by Chimex),
4-methylbenzylidene camphor (sold under the name "Eusolex 6300" by
Merck), benzylidene camphor sulphonic acid (manufactured under the
name "Mexoryl SL" by Chimex), camphor benzalkonium methosulphate
(manufactured under the name "Mexoryl SO" by Chimex),
terephthalylidene dicamphor sulphonic acid (manufactured under the
name "Mexoryl SX" by Chimex), or polyacrylamidomethyl benzylidene
camphor (manufactured under the name "Mesoryl SW" by Chimex),
[0066] benzimidazole derivatives, in particular phenylbenzimidazole
sulphonic acid (sold in particular under the trade name "Eusolex
232" by Merck), or disodium phenyl dibenzimidazole tetrasulphonate
(sold under the trade name "Neo Heliopan AP" by Haarmann and
Reimer),
[0067] triazine derivatives, in particular anisotriazine (sold
under the trade name "Tinosorb S" by Ciba Specialty Chemicals),
ethylhexyl triazone (sold in particular under the trade name
"Uvinul T150" by BASF), diethylhexyl butamido triazone (sold under
the trade name "Uvasorb HEB" by Sigma 3V) or 2,4,6-tris(diisobutyl
4'-amino-benzalmalonate)-s-triazine- ,
[0068] benzotriazole derivatives, in particular drometrizole
trisiloxane (sold under the name "Silatrizole" by Rhodia Chimie) or
methylene bisbenzotriazolyl tetramethylbutylphenol (sold in the
solid form under the trade name "Mixxim BB/100" by Fairmount
Chemical or in the micronized form in aqueous dispersion under the
trade name "Tinosorb M" by Ciba Specialty Chemicals),
[0069] anthranilic derivatives, in particular menthyl anthranilate
(sold under the trade name "Neo Heliopan MA" by Haarmann and
Reimer),
[0070] imidazoline derivatives, in particular ethylhexyl
dimethoxybenzylidene dioxoimidazoline propionate,
[0071] benzalmalonate derivatives, in particular polyorganosiloxane
comprising benzalmalonate functional groups (sold under the trade
name "Parsol SLX" by Hoffmann-LaRoche),
[0072] 4,4-diarylbutadiene derivatives, in particular
1,1'-dicarboxy (2,2'-dimethylpropyl)-4,4-diphenylbutadiene,
[0073] and their mixtures.
[0074] The organic photoprotective agents which are more
particularly preferred are selected from the group consisting of
ethylhexyl salicylate, ethylhexyl methoxycinnamate, octocrylene,
phenylbenzimidazole sulphonic acid, benzophenone-3, benzophenone-4,
benzophenone-5, 4-methylbenzylidene camphor, terephthalylidene
dicamphor sulphonic acid, disodium phenyl dibenzimidazole
tetrasulphonate, 2,4,6-tris(diisobutyl
4'-aminobenzalmalonate)-s-triazine, anisotriazine, ethylhexyl
triazone, diethylhexyl butamido triazone, methylene
bisbenzotriazolyl tetramethylbutylphenol, drometrizole trisiloxane,
1,1'-dicarboxy (2,2'-dimethylpropyl)-4,4-diphenylbutadiene, and
their mixtures.
[0075] The inorganic photoprotective agents may be selected from
the group consisting of pigments or alternatively nanopigments
(mean size of the primary particles: generally between 5 nm and 100
nm, preferably between 10 nm and 50 nm) formed from coated or
uncoated metal oxides, such as, for example, titanium oxide
(amorphous or crystalline in the rutile and/or anatase form), iron
oxide, zinc oxide, zirconium oxide or cerium oxide nanopigments,
which are all UV photoprotective agents well known per se.
Conventional coating agents are, furthermore, alumina and/or
aluminium stearate. Such nanopigments formed from coated or
uncoated metal oxides are disclosed in particular in Patent
Applications EP 518 772 and EP 518 773.
[0076] The photoprotective agents may generally be present in the
compositions according to the invention in proportions ranging from
0.1 to 20% by weight with respect to the total weight of the
composition and preferably ranging from 0.2 to 15% by weight with
respect to the total weight of the composition.
[0077] In another advantageous aspect of the invention, the
composition can additionally comprise at least one other agent
selected from the group consisting of scavengers for ozone,
scavengers for heavy metals and agents for combatting free
radicals.
[0078] Mention may in particular be made, as scavengers for ozone
which can be used in the composition according to the invention, of
phenols and polyphenols, in particular tannins, ellagic acid and
tannic acid; epigallocatechin and the natural extracts comprising
it; olive tree leaf extracts; tea extracts, in particular green tea
extracts; anthocyanins; rosemary extracts; phenolic acids, in
particular chorogenic acid; stilbenes, in particular resveratrol;
sulphur-comprising amino acid derivatives, in particular
S-carboxymethylcysteine; ergothioneine; N-acetylcysteine; chelating
agents, such as N,N'-bis(3,4,5-trimethoxybenz- yl)ethylenediamine
or one of its salts, metal complexes or esters; carotenoids, such
as crocetin; and various starting materials, such as the mixture of
arginine, histidine ribonucleate, mannitol, adenosine triphosphate,
pyridoxine, phenylalanine, tyrosine and hydrolysed RNA sold by
Laboratoires Srobiologiques under the trade name CPP LS
2633-12F.RTM., the water-soluble maize fraction sold by Solabia
under the trade name Phytovityl.RTM., the mixture of fumitory
extracts and of lemon extracts sold under the name Unicotrozon
C-49.RTM. by Induchem and the mixture of extracts of ginseng, of
apple, of peach, of wheat and of barley sold by Provital under the
trade name Pronalen Bioprotect.RTM..
[0079] Finally, mention may in particular be made, as scavengers
for heavy metals which can be used in the composition according to
the invention, of chelating agents, such as EDTA, the pentasodium
salt of ethylenediaminetetramethylenephosphonic acid, and
N,N'-bis(3,4,5-trimetho- xybenzyl)ethylenediamine or one of its
salts, metal complexes or esters; phytic acid; chitosan
derivatives; tea extracts, in particular green tea extracts,
tannins, such as ellagic acid; sulphur-comprising amino acids, such
as cysteine; water hyacinth (Eichomia crassipes) extracts; and the
water-soluble maize fraction sold by Solabia under the trade name
Phytovityl.RTM..
[0080] The agents for combatting free radicals which can be used in
the composition according to the invention comprise, in addition to
certain agents for combatting pollution mentioned above, vitamin E
and its derivatives, such as tocopheryl acetate; bioflavonoids;
coenzyme Q10 or ubiquinone; certain enzymes, such as catalase,
superoxide dismutase, lactoperoxidase, glutathione peroxidase and
quinone reductases; glutathione; benzylidene camphor;
benzylcyclanones; substituted naphthalenones; pidolates;
phytantriol; .gamma.-oryzanol; lignans; and melatonin.
[0081] The composition according to the invention can be applied
for example to the skin or lips. It can thus be used in a cosmetic
treatment process for the purpose of preventing or combatting the
harmful effects of UV radiation and/or of pollution on the skin or
mucous membranes, comprising the application of the composition
according to the invention to the skin or mucous membranes.
[0082] The invention also relates to a cosmetic treatment process
for the purpose of preventing or combatting loss of firmness and/or
of elasticity of the skin or mucous membranes, comprising the
application of the composition according to the invention to the
skin or mucous membranes.
[0083] The composition according to the invention can also be used
for the manufacture of a dermatological preparation comprising an
aqueous phase which is intended to prevent or combat harmful
effects of UV radiation and/or of pollution on the skin.
[0084] In another embodiment, the composition according to the
invention can be used for the manufacture of a dermatological
preparation comprising an aqueous phase which is intended to
prevent or combat loss of firmness and/or elasticity of the
skin.
[0085] The examples which follow serve to illustrate the invention
without, however, exhibiting a limiting nature. The compounds are,
depending on the situation, cited according to chemical names or
according to CTFA (International Cosmetic Ingredient Dictionary and
Handbook) names.
EXAMPLES
Example 1
Accelerated Storage Test
[0086] The aim of this test is to study the decomposition of an
oxidation-sensitive hydrophilic active principle after storing for
two months at 45.degree. C. Various solutions were prepared and
their compositions are collated in the following table:
1TABLE I Compositions (in Solution A water) (Control) Solution B
Solution C Solution D Ascorbic acid 15% 15% 15% 15% Polymer 1 -- 1%
-- -- Polymer 2 -- -- 1% -- Polymer 3 -- -- -- 1%
[0087] All the solutions are brought to pH 6 with 8.9 mol/l
KOH.
[0088] The percentages of the polymers are given as active
material.
[0089] Polymer 1: Vinylpyrrolidone/vinylimidazole (50/50) copolymer
sold under the reference Luvitec VPI 55K72W of BASF (Weight-average
molecular mass 1.2.times.10.sup.6).
[0090] Polymer 2: Vinylpyrrolidone/vinylimidazole (50/50) copolymer
sold under the reference Luvitec VPI 55K18P of BASF (Weight-average
molecular mass 10 000).
[0091] Polymer 3: Polyvinylpyrrolidone sold under the reference
Kollidon 12PF of BASF (Weight-average molecular mass 3 000).
[0092] The degree of decomposition measured is given by the
ratio:
(C.sub.0-C.sub.2 months)/CO
[0093] with C.sub.0 concentration of ascorbic acid at t=0 and
C.sub.2 months the concentration of ascorbic acid at t=2 months,
under the conditions indicated in the above table.
[0094] The concentration of ascorbic acid is determined by the HPLC
technique (LaChrom Merck system). The analytical conditions are as
follows:
[0095] Column: Lichrosphere100 RP18 (250 mm)
[0096] Eluent: 0.1M phosphate buffer, pH 2.1
[0097] Flow rate: 1 ml/min
[0098] Detection at 257 nm
[0099] Dilution of the sample such that the concentration of
ascorbic acid is between 0.05 and 1 mg/ml.
[0100] The results obtained are collated in the following Table
II:
2 TABLE II Degree of decomposition after 2 months at 45.degree. C.
(in %) under air, amber glass bottle under nitrogen, aluminium
flask Solution A 43 19.4 Solution B 10.8 1 Solution C 23.4 4.5
Solution D 35.8 15.7
[0101] It is found, from Table II, that the stability of ascorbic
acid is improved in the presence of Polymer 1 and Polymer 2 of the
invention, even in the presence of atmospheric oxygen, in
comparison with the control. It is also found that the
N-vinylpyrrolidone homopolymer alone is not sufficient to
effectively stabilize the ascorbic acid solution.
[0102] As the polymers mentioned are hydrophilic, it would be
sufficient to add them to an aqueous ascorbic acid solution to
stabilize the ascorbic acid.
Example 2
Demonstration of the Activity in Combatting Free Radicals
[0103] I. Principle
[0104] This test makes it possible to evaluate the effect of a
molecule in combatting OH.sup.o.
[0105] It is based on the measurement by gas chromatography of the
ethylene formed from the oxidation of methionine by the hydroxyl
radical. The latter is generated by a ferro-catalysed Fenton
reaction maintained by the continuous generation of superoxide
anions. The anions O2.sup.o--are produced by photochemical
reduction at 365 nm of riboflavin (RBF) by a hydrogen donor,
according to the following scheme: 1
RBFH.sub.2+O.sub.2.fwdarw.RBF+2 O.sub.2.sup.o-+2H.sup.+
2 O.sub.2.sup.o-+2H.sup.+.fwdarw.H.sub.2O.sub.2+O.sub.2
O.sub.2.sup.o-+L--Fe.sup.3+.fwdarw.O.sub.2+L--Fe.sup.2+
H.sub.2O.sub.2+L--Fe.sup.2+.fwdarw.L--Fe.sup.3++OH.sup.-+OH.sup.o
CH.sub.3--S--CH.sub.2--CH(COOH)--NH.sub.2+OH.sup.o.fwdarw.CH.sub.2=CH.sub.-
2+products
[0106] The neutralization of the OH.sup.o radicals is reflected by
inhibition of the production of ethylene.
[0107] II. Procedure
[0108] Irradiation equipment: 3 low-pressure mercury vapour
tubes.
[0109] The tested products are dissolved in a phosphate buffer.
They are tested at final concentrations in the reaction mixture
generally ranging from 0.1 to 3%, according to their solubility.
The final volume is 2 ml.
[0110] The separation distance for exposure under the UV bank is
adjusted in order to have an exposure time of approximately 8
minutes for a UV-A dose of 1 joule/cm.sup.2 and in order not to
adjust this setting throughout the duration of the test.
[0111] The following are introduced in this order into a head space
flask:
[0112] 1.4 ml of phosphate buffer
[0113] 100 .mu.l of 200 mM methionine solution
[0114] 100 .mu.l of 4 mM ferric chloride solution
[0115] 100 .mu.l of phosphate buffer, pH 7.4, (control) or of
solution comprising the active principle to be tested
[0116] 100 .mu.l of 4 mM EDTA solution
[0117] 100 .mu.l of 400 mM NADH solution
[0118] The samples and the blanks are all prepared in succession
and are kept sheltered from the light.
[0119] The UV-A bank is switched on, displaying a number of joules
at least equal to the number of samples. The samples are irradiated
one by one at intervals of 0.5 joules.
[0120] Every 0.5 joules:
[0121] 100 .mu.l of riboflavin are added
[0122] mixing is carried out
[0123] the sample is irradiated with 1 joule
[0124] the reaction is halted with 0.5 ml of IN NaOH
[0125] the sample is sheltered from the light
[0126] The flasks are inserted into the sample changer of the
chromatograph. The ethylene peak exits at a retention time of
approximately 2.00 minutes. A minimum of 3 measurements are carried
out per sample.
[0127] III. Results:
[0128] The results are expressed as percentage of inhibition of
production of ethylene with respect to the control solution.
[0129] It is apparent that, for the tested samples comprising the
ascorbic acid and N-vinylimidazole/N-vinylpyrrolidone copolymer
combination, inhibition of the production of ethylene is increased
with respect to the control, thus demonstrating the activity in
combatting free radicals of this combination.
Example 3
O/W cream
[0130] The following composition is prepared in a way conventional
to a person skilled in the art.
3 Glyceryl stearate and PEG-100 stearate 2.5 g PEG-50 stearate 2.5
g Cetyl alcohol 1 g Stearyl alcohol 1 g Hydrogenated polyisobutene
5 g Water 12.23 g Glycerol 5 g Cyclopentasiloxane 15 g Carbomer 0.6
g Phenoxyethanol 1 g Water 45.17 g Ascorbic acid 5 g Potassium
hydroxide (50% solution) 3 g Vinylpyrrolidone/vinyli- midazole
copolymer 1 g
[0131] This soft cream, on application, makes it possible to smooth
out the lines of the face and exhibits good stability for ascorbic
acid.
Example 4
W/O emulsion
[0132] The following composition is prepared in a way conventional
to a person skilled in the art.
4 Water 45.17 g Ascorbic acid 5 g Potassium hydroxide (50%
solution) 3 g Vinylpyrrolidone/vinylimid- azole copolymer 1 g
Glycerol 5 g Phenoxyethanol 1 g Cyclopentasiloxane and dimethicone
copolyol 20 g Phenyl trimethicone 4 g Prunus armeniaca (apricot)
kernel oil 3.5 g Dimethicone and 5 g Dimethicone/vinyl dimethicone
crosspolymer Nylon-12 5 g
[0133] A white water-in-oil emulsion is obtained, which emulsion is
capable of smoothing out the lines of the face and in which
emulsion ascorbic acid has good stability.
[0134] The above description, as illustrated by non-limiting
examples, allows one of ordinary skill in the art to make and use a
composition for preventing or combatting the harmful effects of UV
radiation and/or of pollution on the skin comprising, preferably in
a physiologically acceptable medium comprising an aqueous phase, at
least one oxidation-sensitive hydrophilic active principle selected
from the group consisting of ascorbic acid and its derivatives and
at least one non-crosslinked N-vinylimidazole polymer or copolymer,
the active principle and the polymer or copolymer both being
present in the aqueous phase. Also provided is a method for
preventing or combatting loss of firmness and/or of elasticity of
the skin, for soothing sunburn, and to prevent or combat the
harmful effects of UV radiation and/or of pollution on the skin
using this composition, and the use of a combination composed of at
least one oxidation-sensitive hydrophilic active principle selected
from the group consisting of ascorbic acid and its derivatives and
of at least one non-crosslinked N-vinylimidazole polymer or
copolymer in the aqueous phase of a cosmetic composition as agent
for combatting free radicals. Further provided is a cosmetic
treatment process to prevent or combat the harmful effects of UV
radiation and/or of pollution on the skin or mucous membranes,
comprising the application, to the skin or mucous membranes, of a
composition comprising, preferably in a physiologically acceptable
medium comprising an aqueous phase, at least one
oxidation-sensitive hydrophilic active principle selected from the
group consisting of ascorbic acid and its derivatives and at least
one non-crosslinked N-vinylimidazole polymer or copolymer, the
active principle and said polymer or copolymer both being present
in the aqueous phase, and a cosmetic process to combat loss of
firmness and/or of elasticity of the skin or mucous membranes,
comprising the application, to the skin or mucous membranes, of a
composition comprising, preferably in a physiologically acceptable
medium comprising an aqueous phase, at least one
oxidation-sensitive hydrophilic active principle selected from the
group consisting of ascorbic acid and its derivatives and at least
one non-crosslinked N-vinylimidazole polymer or copolymer, the
active principle and the polymer or copolymer both being present in
the aqueous phase.
[0135] French patent application 0115375 is incorporated herein by
reference, as are all references, texts, documents, articles,
standards, patents, applications, etc., mentioned above. All
numerical ranges include all values therebetween as if specifically
written out.
[0136] Also incorporated herein by reference are the following U.S.
applications, all filed Nov. 27, 2002, where the present
application is listed for information only:
5 U.S. Ser. No. . . . (Atty. Docket 230634US0) U.S. Ser. No. . . .
(Atty. Docket 230608US0) U.S. Ser. No. . . . (Atty. Docket
230616US0) U.S. Ser. No. . . . (Atty. Docket 230614US0) U.S. Ser.
No. . . . (Atty. Docket 230615US0)
* * * * *