Note: Descriptions are shown in the official language in which they were submitted.
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Skin Care Product
This invention relates to cosmetic and dermatological compositions
for the care of sensitive skin in the form of an emulsion or cream which,
through the presence of specially selected fatty components, emulsifiers
and active ingrediE~nts, nol: only have a negligible irritating effect on the
skin, but also increase the vitality of the skin tissue.
The cosmetic care of sensitive skin is acquiring increasing
significance because, today, more than 50% of consumers regard their skin
as sensitive. Although the notion of sensitive skin has not been clearly
defined in the cosrnetic literature, there are tests which enable the
irritation
potential of skin trE~atment compositions to be tested extremely accurately
and which provide information on positive effects, for example on the effect
on the cell metabolism of the skin.
Polysaccharides, sugars and glycoproteins are known in the
cosmetics field as skin-moisturizing components. The anti-allergic effects
of an addition of L-a-fucose, L-rhamnose and L-xylose to cosmetic and
dermatological cornpositions was already known from FR-A-2 652 742.
However, it has been found that the effect of such compositions on
the skin can be considerak>ly improved if the carrier components, i.e. the oil
and fatty components and emulsifiers in the case of emulsions and creams,
are further optimized in reciard to their irritation potential.
Accordingly, the present invention relates to improved compositions
for the care of sensitive skin in the form of an emulsion or cream which
contain natural oils, and fats or waxes or esters of linear C$-22 fatty acids
as
oil or fatty components and phospholipids, sterols, alkyl (oligo)glycosides,
fatty acid esters of sugars, sugar alcohols or polyglycerol or mixtures
thereof as emulsifiers and deoxy sugars or natural substances containing
such sugars as aci;ive ingredients.
In the context of the present invention, deoxy sugars are preferably
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L(-) fucose and L(-~) rhamnose. However, natural substances containing
such deoxy sugar units, for example polysaccharides or vegetable
glycosides, are also suitable. Fucose occurs, for example, as a
polysaccharide unit in a polysaccharide gel isolated from brown algae
(fucus vesiculosus). Rhamnose is a polysaccharide unit of arabic acid in
gum arabic. The composition according to the invention preferably
contains fucose, rhamnosc: or a mixture thereof in quantities of 0.1 to 10%
by weight.
Suitable carriers for' these active ingredients are emulsions or
creams which are capable of applying the active ingredients to the skin in
fine distribution without any skin-irritating side effects. It has
surprisingly
been found that typical hydrocarbons, for example paraffin oils, Vaseline
(petrolatum) or silicones, are not as suitable for this purpose and,
accordingly, should only be present in the compositions according to the
invention in small quantities.
Instead, the oil or fatty phase should mainly consist of natural oils,
fats and waxes or of esters of linear C$_22 fatty acids. Examples of such
suitable oils and fats include olive oil, sunflower oil, refined soybean oil,
palm oil, rapeseed oil, sesame oil, almond oil) borage oil, night light oil,
jojoba oil, coconut oil, she<~.butter, sperm oil, neat's foot oil, beef tallow
and
lard. Also suitable are esters of linear C8_22 fatty acids, for example oleyl
oleate, oleyl erucai:e, hexyll laurate, caprylic and capric acid triglyceride,
isopropyl palmitate or butyl stearate. Oils with a high percentage content of
gamma-linolenic acid (6,9) 12-octadecatriene carboxylic acid) are preferably
present in a quantity of 10 to 50% by weight of the oil phase.
In one particularly preferred embodiment, the compositions
according to the im~ention contain she, butter from the seed of the plant
Butyrospermum pairkii, almiond oil, night light oil or a caprylic and capric
acid triglyceride or mixture, of these fats in a quantity of 10 to 30% by
weight, based on the composition as a whole, as the oil or fatty component.
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By contrast, the oil or fatty phase should not contain any more than 5% by
weight of hydrocarbons or silicone oils.
Phospholipids suitable as emulsifiers are, above all, glucose
phospholipids which are obtained, for example) as lecithins or phosphatidyl
cholines, for example from egg yolk or plant seeds (for example soya
beans).
Sterols are understood to be a group of steroids which carry a
hydroxyl group at carbon atom 3 of the steroid skeleton and which are
isolated both from animal tissue (zoosterols) and from vegetable fats
(phytosterols). Examples ~of zoosterols are cholesterol and lanosterol.
Examples of suitable phytosterols are ergosterol, stigmasterol and
sitosterol. Sterols are also isolated from fungi and yeasts (so-called
mycosterols).
Alkyl (oligo)glycosides are compounds with the general formula
RO(G)X, in which F; is a linear alkyl group containing 8 to 18 carbon atoms,
G is a glycoside unit, for e:Kample the glucoside unit derived from glucose
or a mannoside or fructoside unit derived, or example, from mannose or
fructose) and x - the degree of oligomerization - preferably has a value
between 1 and 2. Alkyl glycosides such as these are commercially
available, for example, under the registered names of Plantaren~ or
Plantacare~. Mixtures of alkyl (oligo)glucosides and fatty alcohols are
marketed, for example, under the names of Montanov~ 68 or Emulgade~
PL 68/50.
Fatty acid eaters of sugars, sugar alcohols, such as sorbitol, and
polyglycerols are also known and commercially available emulsifiers.
The compositions according to the invention preferably contain no
more than 1 % by weight, if any) of sulfate or sulfonate surfactants, ethylene
oxide or propylene oxide adducts and quaternary ammonium surfactants.
Besides the oil and fatty components and the emulsifiers, the oil and
fatty phase may contain further lipids which help to stabilize the
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4
compositions and to care for the skin. Suitable lipids are, for example,
tocopherols (vitamin E) and ceramides. Ceramides are understood to be
N-acyl sphingosine (fatty acid amides of sphingosine) and synthetic
analogs of such lipids (so-called pseudoceramides) which distinctly
improve the water retaining capacity of the stratum corneum.
Finally, the compositions according to the invention may contain any
of the auxiliaries and additives typically present in such compositions which
are known to improve their aesthetic, performance and cosmetic
properties. Exams>les of such auxiliaries and additives include natural or
synthetic hydrocolloids, for example cellulose derivatives, vegetable gums,
gelatin, biopolymeirs or even synthetic water-soluble polymers for
thickening the aqueous phase, layer silicates, soaps, for example calcium,
magnesium or zinc; soaps for thickening the oil phase, perfumes, dyes,
pigments, preservatives, complexing agents, polyols such as, for example,
propylene glycol, dlipropyle~ne glycol, sorbitol or glycerol and cosmetic
ingredients such aa, for example, allantoin, bisabolol, extracts from
vegetable or animal tissue or from microorganisms (for example yeast
extracts)) vitamins or proteins.
The aqueous phase: preferably contains a natural or synthetic
hydrocolloid in a quantity of 0.01 to 5% by weight, based on the
composition as a whole.
The cosmetic compositions according to the invention are prepared
in the usual way b~~ heating the lipid-soluble ingredients with the oil or
fatty
phase to form a clear melt and, after homogenization, dissolving the water-
soluble ingredients. in the water and emulsifying the heated aqueous phase
while stirring into the fatty phase. The aqueous phase may be emulsified
into the fatty phasE~ with the aid of homogenizers. The deoxy sugar is
incorporated either' in the oil phase or in the final emulsion. Perfumes and
heat-sensitive ingredients ~or plant extracts are also preferably incorporated
in the emulsion in a subsequent step.
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The following Examples are intended to illustrate the invention.
Examples
5 1.1 Testing of ~dermatological compatibility by the double
application prolonged patch test (DAPPT)
The test was carried out and the results evaluated on the basis of
the known Duhring Chamber Test (cf. I. Tausch et al., Paerfuemerie and
Kosmetik, 76 (1196), pages 28-31). However) in order to enable readily
compatible products to be more clearly differentiated, the samples fixed to
the back of 20 volunteers by means of aluminium chambers in the DAPPT
were tested over a first exposure period of 48 hours and immediately
afterwards over a second exposure period of 72 hours. The change in the
skin caused by the samples was then visually evaluated over a period of
another 72 hours. Distinctions were made between erythema, squamation,
oedema and fissures.
From the data of all the volunteers over all the read-off times,
average values were calculated out both for each parameter individually
and also for the sum total of the parameters (total irritation score).
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1.2 Skin care formulations tested
Table I
Ingredients 1V 2V 3 4 5
Lipoid S-75 3.0 - - 3.0 -
Montanov~68 - 5.0 5.0 - -
Generol~ 122N - 0.5 0.5 - 1.0
Ceramide H03 - 0.2 0.2 - -
Beeswax 1.5 - - 1.5 -
Cetiol SB 45 9.0 1.0 1.0 9.0 3.0
Cetiol J 600 5.0 - - 5.0 -
Myritol318 - 4.0 4.0 - -
Cetiol SN - 5.0 5.0 - -
Almond oil 5.0 2.0 2.0 5.0 -
Night light oil - 5.0 5.0 - 5.0
Rhamnose - - 1.5 1.5 1.5
Fucoge11000 - - 2.5 2.5 2.5
Tufskin - - 1.5 1.5 1.5
Bisbolol - - 0.1 0.1 0.1
Allantoin - - 0.2 0.2 0.2
Glycerol 5.0 - 5.0 -
Dipropylene glycol - 5.0 5.0 - -
Carbopo1980 - 0.005 0.005 - -
Carrageenin 2.0 - - 2.0 -
Water, preservative to 100 to 100 to 100 to 100
Compatibility parameters
Erythema score 0 0.17 0.06 0 n.b.
Total irritation score 0.11 0.44 0.06 0 n.b.
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In the case of low-compatibility skin creams which achieved an
erythema score of 1 to 2 and a total irritation score of 4 to 5 in the test,
compatibility was iimproved by 85% by adding an active-ingredient complex
according to formulation 5 (in which the balance to 100% by weight
consisted of the comparison cream).
The following commercial products were used (by way of
explanation, the INCI nomenclature is used where possible):
Lipoid S-75: Hydrogenated Lecithin
Montanov 68: Cetearyl Glucoside, cetearyl alcohol
Generol 122N: Soy Sterol
Ceramide H03: Trihydroxy-Palmitamidohydroxypropyl-Myristyl-Ether
Cetiol SB 45: Buytoapermum parkii (shea butter)
Cetiol J 600: Oleyl Erucate
Myritol 318:Capryl/Capric Triglycerides
Cetiol SN: Cetearyl Isononanoate
Tufskin: Sorbitol and Yeast Extract
Fucogel 1000: Biosaccharide Gum (rich in fucose)
Carbopol 980: Carbomer (polyacrylic acid, crosslinked).
2. Testing of ithe increase in vitality using a human skin model
A three-dimensional skin model was used for these tests. It consists
of a culture of human skin cells (Skin2 from Advanced Tissue Sciences,
La Jolla, Ca., USA, cf. Alternative Methods in Toxicology, Vol. 10, B III-
4, pages 121-131).
The creams to be tE~sted were applied to a filter paper which was
then placed with the crearr~-coated side on the surface of the skin culture
for 2 hours so that the creams could act.
The vitality of the skin cultures was tested using the vital dye
Alamarblau. Living cells reduce the dye molecule, causing a change in
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color of which the intensity was photometrically measured. The more vital
the cultures, the higher the' reduction rate. The metabolic activity was
determined by measuring the consumption of glucose. Glucose is the
principal nutrient for the skin cells (cf. Toxic. in Vitro, Vol. 9, No. 3,
pages
257 - 266, ElseviE:r Science Ltd., 1995).
For both cream forrnulations, the results show an increase in the
Alamarblau reduction rate and the glucose consumption compared with the
untreated control ('V) on the first two treatment days.
Table II
Vitality test
Formulation: V 1V 3
Dye reduction per hour Untreated
First day 1.64 1.95 1.92
Second day 1.93 2.10 2.17
Glucose consumption (in
pg/h)
First day 59.5 68.1 83.9
Second day 67.4 73.4 79.6
3. Testing of ithe skin-soothing effect using a human skin model
(for cream 3 of Table I)
The three-dimensional skin model described above was used for
this test also.
First, irritation of they skin was induced by a synthetic surfactant
mixture (Texapon~J ASV, 2..5% by weight, 1 hour) which resulted in
secretion of the pro-inflammatory mediators interleucine 1 alpha and
prostaglandin PGE: 2. After the surfactant had been rinsed off, cream
formulations were applied to the pieces of skin. A cortisone ointment
known for its skin-:>oothing effect was used for comparison.
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In the measurements, three skin cultures were used for each test
cream. Quantities of 3 NI of each cream were applied to the filter paper
which was then placed with the cream-coated side on the surface of the
skin culture and left there for 1 hour. The quantities of mediators released
in the skin cultures; were determined after 24 and 48 hours (from the
beginning of the skin irritation). The so-called ELISA technique (enzyme-
linked immunosork>ant assay) was used (cf. D. Voet) J.G. Voet: Biochemie,
VCH Verlagsgese~llschaft mbH, Weinheim, 1992, pages 74 - 75).
In the following Table, the quantities of interleucine 1 a and
prostaglandin are shown in % by weight, based on the quantity of
mediators measurE~d on the untreated sample 24 hours after the irritation
treatment (100% value).
Table III
Skin-soothing effect
Formulation Untreated Cortisone 3
Prostaglandin [%]
After 24 hours 100 39.8 120
After 48 hours 62 25.0 26.2
Interleucine 1 a [%]
After 24 hours 100 69.5 66.2
After 48 hours 26.5 25.8 14.6
