U.S. patent application number 09/396918 was filed with the patent office on 2002-05-09 for emulsifier-free finely disperse systems of the oil-in-water and water-in-oil type.
Invention is credited to GERS-BARLAG, HEINRICH, MULLER, ANJA.
Application Number | 20020054890 09/396918 |
Document ID | / |
Family ID | 7881362 |
Filed Date | 2002-05-09 |
United States Patent
Application |
20020054890 |
Kind Code |
A1 |
GERS-BARLAG, HEINRICH ; et
al. |
May 9, 2002 |
EMULSIFIER-FREE FINELY DISPERSE SYSTEMS OF THE OIL-IN-WATER AND
WATER-IN-OIL TYPE
Abstract
Pickering emulsions, which are finely disperse systems of the
water-in-oil or oil-in-water type, comprising (1) an oil phase
which contains at least one wax and/or one oil thickener, (2) a
water phase, (3) at least one type of microfine particles which a)
have an average particle size of less than 200 nm, which b) display
both hydrophilic and lipophilic properties, i.e. which have
amphiphilic character, and are dispersible both in water and in oil
and which c) have optionally been coated on the surface, and (4) at
most 0.5% by weight of one or more emulsifiers.
Inventors: |
GERS-BARLAG, HEINRICH;
(KUMMERFELD, DE) ; MULLER, ANJA; (RUMPEL,
DE) |
Correspondence
Address: |
NORRIS, MCLAUGHLIN & MARCUS, P.A.
220 EAST 42ND STREET
30TH FLOOR
NEW YORK
NY
10017
US
|
Family ID: |
7881362 |
Appl. No.: |
09/396918 |
Filed: |
September 15, 1999 |
Current U.S.
Class: |
424/401 |
Current CPC
Class: |
A61Q 19/00 20130101;
A61K 2800/33 20130101; A61K 2800/413 20130101; B82Y 5/00 20130101;
A61Q 17/04 20130101; A61K 8/19 20130101; A61K 8/29 20130101; A61K
8/06 20130101; A61Q 15/00 20130101; A61K 8/27 20130101; A61K 8/37
20130101; A61Q 1/02 20130101; Y10S 514/938 20130101; A61K 8/25
20130101; A61K 8/375 20130101; A61Q 1/14 20130101 |
Class at
Publication: |
424/401 |
International
Class: |
A61K 006/00; A61K
007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 18, 1998 |
DE |
198 42 730.1 |
Claims
1. Pickering emulsions, which are finely disperse systems of the
water-in-oil or oil-in-water type, comprising (1) an oil phase
which contains at least one wax and/or one oil thickener, (2) a
water phase, (3) at least one type of microfine particles which a)
have an average particle size of less than 200 nm, which b) display
both hydrophilic and lipophilic properties, i.e. which have
amphiphilic character, and are dispersible both in water and in oil
and which c) have optionally been coated on the surface, and (4) at
most 0.5% by weight of one or more emulsifiers.
2. Pickering emulsions according to claim 1, characterized in that
they are emulsifier-free.
3. Pickering emulsions according to one of the preceding claims,
characterized in that the content of the particles used is between
0.1% by weight and 30% by weight, based on the total weight of the
preparations.
4. Pickering emulsions according to one of the preceding claims,
characterized in that the particle diameter of the particles used
is between 5 nm and 100 nm.
5. Pickering emulsions according to one of the preceding claims,
characterized in that the particles used are chosen from the group
consisting of amphiphilic metal oxides, boron nitride, microfine
polymer particles and modified polysaccharides, it being possible
for the particles to be present individually or as a mixture.
6. Pickering emulsions according to one of the preceding claims,
characterized in that the particles used have been surface-treated
to repel water, where the amphiphilic character of the particles is
formed or retained.
7. Pickering emulsions according to one of the preceding claims,
characterized in that the total amount of one or more waxes and/or
oil thickeners in the finished cosmetic or dermatological
preparations is chosen to be from the range of 0.5 to 20.0% by
weight, preferably between 1.0 and 5.0% by weight, based on the
total weight of the preparations.
8. Pickering emulsions according to one of the preceding claims,
characterized in that the waxes and/or oil thickeners together with
the other oil components of the preparations form a material which
is pasty and spreadable at room temperature and which has a
viscosity of more than 5000 mPa.multidot.s at 20.degree. C.
9. Pickering emulsions according to one of the preceding claims,
characterized in that the wax(es) is/are selected from the group
consisting of the natural and/or synthetic, modified and/or
unmodified waxes.
10. Pickering emulsions according to one of the preceding claims,
characterized in that the oil thickener(s) is/are selected from the
group consisting of the metal soaps and/or from the group
consisting of the layered silicates.
11. Pickering emulsions according to one of the preceding claims,
characterized in that they comprise auxiliaries which can
contribute to reducing or preventing a dull or dry feel on the skin
following their application.
12. Use of at least one wax and/or oil thickener in a cosmetic or
dermatological preparation for reducing or preventing a dull or dry
feel on the skin following its application.
13. Use of at least one wax and/or oil thickener for stabilizing a
cosmetic or dermatological Pickering emulsion.
Description
[0001] The present invention relates to emulsifier-free finely
disperse systems of the oil-in-water and water-in-oil type,
preferably as cosmetic or dermatological preparations.
[0002] Emulsions are generally taken to mean heterogeneous systems
which consist of two liquids which are immiscible or have only
limited miscibility with one another, which are usually referred to
as phases. In an emulsion, one of the two liquids is dispersed in
the form of very fine droplets in the other liquid.
[0003] If the two liquids are water and oil and if oil droplets are
finely dispersed in water, then this is an oil-in-water emulsion
(O/W emulsion, e.g. milk). The basic character of an O/W emulsion
is defined by the water. In a water-in-oil emulsion (W/O emulsion,
e.g. butter), the principle is reversed, the basic character here
being determined by the oil.
[0004] In order to achieve permanent dispersion of one liquid in
another, emulsions in the traditional sense require the addition of
an interface-active substance (emulsifier). Emulsifiers have an
amphiphilic molecular structure, consisting of a polar
(hydrophilic) and a nonpolar (lipophilic) molecular moiety, which
are spatially separate from one another. In simple emulsions,
finely disperse droplets of one phase, surrounded by an emulsifier
shell, (water droplets in W/O emulsions or lipid vesicles in O/W
emulsions) are present in the second phase. Emulsifiers lower the
interfacial tension between the phases by positioning themselves at
the interface between two liquids. At the phase boundary, they form
oil/water interfacial films, which prevent irreversible coalescence
of the droplets. Emulsions are frequently stabilized using
emulsifier mixtures.
[0005] Traditional emulsifiers can, depending on their hydrophilic
molecular moiety, be divided into ionic (anionic, cationic and
amphoteric) and nonionic:
[0006] The most well-known example of an anionic emulsifier is
soap, which is usually the term used for the water-soluble sodium
or potassium salts of saturated or unsaturated higher fatty
acids.
[0007] Important examples of cationic emulsifiers are quaternary
ammonium compounds.
[0008] The hydrophilic molecular moiety of nonionic emulsifiers
frequently consists of glycerol, polyglycerol, sorbitans,
carbohydrates and polyoxyethylene glycols, and, in most cases, is
linked to the lipophilic molecular moiety via ester and ether
bonds. The lipophilic molecular moiety usually consists of fatty
alcohols, fatty acids or isofatty acids.
[0009] By varying the structure and the size of the polar and
nonpolar molecular moiety, the lipophilicity and hydrophilicity of
emulsifiers can be varied within wide limits.
[0010] A decisive factor for the stability of an emulsion is the
correct choice of emulsifiers. The characteristics of all
substances present in the system are to be taken into consideration
here. In the case of, for example, skincare emulsions, polar oil
components and, for example, UV filters lead to instability. As
well as the emulsifiers, therefore, other stabilizers are also used
which, for example, increase the viscosity of the emulsion and/or
act as protective colloid.
[0011] Emulsions are an important type of product in the field of
cosmetic and/or dermatological preparations.
[0012] Cosmetic preparations are essentially used for skin care.
The main aim of skin care in the cosmetics sense is to strengthen
or rebuild the skin's natural function as a barrier against
environmental influences (e.g. dirt, chemicals, microorganisms) and
against the loss of endogenous substances (e.g. water, natural
fats, electrolytes). If this function becomes impaired, increased
resorption of toxic or allergenic substances or attack by
microorganisms may result, leading to toxic or allergic skin
reactions.
[0013] Another aim of skin care is to compensate for the loss by
the skin of lipids and water caused by daily washing. This is
particularly important if the natural regeneration ability is
inadequate. Furthermore, skincare products should protect against
environmental influences, in particular against sun and wind, and
delay skin ageing.
[0014] Cosmetic preparations are also used as deodorants. Such
formulations are used to control body odour, which is produced when
fresh perspiration, which is in itself odourless, is decomposed by
microorganisms.
[0015] Medicinal topical compositions usually comprise one or more
medicaments in an effective concentration. For the sake of
simplicity, in order to distinguish clearly between cosmetic and
medicinal use and corresponding products, reference is made to the
legal provisions in the Federal Republic of Germany (e.g. Cosmetics
Directive, Foods and Drugs Act).
[0016] The use of customary emulsifiers in cosmetic or
dermatological preparations is in itself acceptable. Nevertheless,
emulsifiers, like ultimately any chemical substance, may in certain
circumstances cause allergic reactions or reactions based on
oversensitivity of the user.
[0017] For example, it is known that certain light dermatoses are
triggered by certain emulsifiers, but also by various fats and
simultaneous exposure to sunlight. Such light dermatoses are also
called "Mallorca acne". There has thus been no lack of attempts' to
reduce the amount of customary emulsifiers to a minimum, in the
ideal case even to zero.
[0018] A reduction in the required amount of emulsifier can, for
example, be achieved by taking advantage of the fact that very
finely divided solid particles have an additional stabilizing
action. The solid substance accumulates at the oil/water phase
boundary in the form of a layer, as a result of which coalescence
of the disperse phases is prevented. It is not the chemical
properties of the solid particles which are of fundamental
importance here, but the surface properties.
[0019] Around 1910, Pickering prepared paraffin/water emulsions
which were stabilized merely by the addition of various solids,
such as basic copper sulphate, basic iron sulphate or other metal
sulphates. This type of emulsion is thus also referred to as a
Pickering emulsion.
[0020] The original forms of Pickering emulsions initially
surfaced, as it were, as undesired secondary effects in a variety
of industrial processes, such as, for example, in secondary oil
recovery, the extraction of bitumen from tar sand and other
separation processes involving two immiscible liquids and fine,
dispersed solid particles. These are generally W/O emulsions which
are stabilized by mineral solids. Accordingly, investigation of
corresponding systems, such as, for example, the oil/water/soot or
oil/water/slate dust systems was initially the focus of research
activity.
[0021] Basic experiments have shown that one characteristic of a
Pickering emulsion is that the solid particles are arranged at the
interface between the two liquid phases, where they form, as it
were, a mechanical barrier against the combining of the liquid
droplets.
[0022] It is a relatively new technical development to use
Pickering emulsions as a base for cosmetic or dermatological
preparations.
[0023] One way of achieving solids stabilization in the sense of a
pickering emulsion in a cosmetic or dermatological preparation is,
according to May-Alert (Pharmazie in unserer Zeit [Pharmacy in our
time], Vol. 15, 1986, No. 1, 1-7) for example, to use emulsifier
mixtures which comprise both anionic and cationic surfactants.
Since mixing anionic and cationic surfactants always results in the
precipitation of insoluble, electroneutral compounds, deliberate
precipitation of these neutral surfactants in the oil/water
interface makes it possible to achieve additional solids
stabilization.
[0024] European Laid-open Specification 0 686 391, moreover,
describes emulsions of the water-in-oil type which are free from
surface-active substances and are stabilized only by solids.
Stabilization is achieved here using spherical
polyalkylsilsesquioxane particles which have a diameter of from 100
nm up to 20 .mu.m. These emulsions can be referred to as Pickering
emulsions according to that mentioned above.
[0025] Pickering emulsions are stabilized by the use of suitable
solids or pigments. However, the preparations of the prior art
generally have the disadvantage that they are limited to a narrow
field of application or a restricted choice of starting materials
since they can only be stably formulated in this manner. For many
areas of cosmetics (e.g. for the field of face care), Pickering
emulsions of the prior art have unsatisfactory cosmetic
properties.
[0026] The object was therefore to remedy the disadvantages of the
prior art. In particular, the intention was to provide cosmetic and
dermatological bases for cosmetic and dermatological preparations
which are characterized by good skin tolerability.
[0027] In addition, an object of the present invention was to
provide products with the widest possible variety of applications.
For example, the intention was to provide bases for preparation
forms such as cleansing emulsions, facecare and bodycare
preparations or deodorants, but also distinctly
medicinal-pharmaceutical presentations, for example preparations
against acne and other skin conditions.
[0028] It was surprising and in no way predictable by the person
skilled in the art that Pickering emulsions, which are finely
disperse systems of the water-in-oil or oil-in-water type,
comprising
[0029] (1) an oil phase which contains at least one wax and/or one
oil thickener,
[0030] (2) a water phase,
[0031] (3) at least one type of microfine particles which
[0032] a) have an average particle size of less than 200 nm,
which
[0033] b) display both hydrophilic and lipophilic properties, i.e.
which have amphiphilic character, and are dispersible both in water
and in oil and which
[0034] c) have optionally been coated on the surface and
[0035] (4) at most 0.5% by weight of one or more emulsifiers,
overcome the disadvantages of the prior art.
[0036] According to the invention, it is particularly advantageous
if the preparations comprise significantly less than 0.5% by weight
of one or more emulsifiers or are even entirely free from
emulsifiers.
[0037] The preparations according to the invention are extremely
satisfactory preparations in every respect which have considerably
higher stability compared with traditional Pickering emulsions and
are therefore suitable in particular to serve as bases for
preparation forms having diverse application purposes. In
particular, W/O Pickering emulsions within the meaning of the
present invention are, surprisingly, markedly stable.
[0038] In addition, the preparations according to the invention are
characterized by excellent skin tolerability. In addition, it was
surprising that preparations according to the invention, which are
in the form of a sunscreen, exhibit higher effectiveness than
customary sunscreen formulations.
[0039] While preparations of the prior art having a pigment content
of as little as 1% by weight produce a dull feel following their
application to the skin, which increases further with higher
pigment concentrations, the preparations according to the
invention, surprisingly, do not leave a dry or dull impression on
the skin, but on the contrary exhibit excellent cosmetic
properties.
[0040] Although the prior art recognizes, in addition to Pickering
emulsions, emulsifier-free, finely disperse cosmetic or
dermatological preparations, which are generally referred to as
hydrodispersions and which are dispersions of a liquid, semisolid
or solid inner (discontinuous) lipid phase in an outer aqueous
(continuous) phase, the prior art was unable to point the way to
the present invention.
[0041] In hydrodispersions of a liquid lipid phase in an external
aqueous phase, the stability can be guaranteed, for example, by
building up a gel structure in the aqueous phase in which the lipid
droplets are stably suspended.
[0042] German Laid-Open Specification 44 25 268 describes stable
finely dispersed, emulsifier-free cosmetic or dermatological
preparations of the oil-in-water type which, in addition to an oil
and a water phase, contain one or more thickeners from the group
consisting of the acrylic acid polymers, polysaccharides and their
alkyl ethers, where for these thickeners a lowering of interfacial
tension must not be measurable.
[0043] Based on similar hydrodispersions, German Laid-Open
Specification 43 03 983 discloses cosmetic or dermatological
sunscreen formulations which are essentially free of emulsifiers,
inorganic micropigments which serve as UV filter substances being
incorporated into the lipid phase of the hydrodispersion.
[0044] O/W Pickering emulsions within the meaning of the present
invention, however, are obtainable by first dispersing amphilic
particles according to the invention, which are suitable for the
preparation of O/W Pickering emulsions, in the aqueous phase and
then combining the aqueous phase with the fatty phase. W/O
Pickering emulsions according to the invention, however, are
obtainable by dispersing amphilic particles which are suitable for
the preparation of W/O Pickering emulsions in the fatty phase.
[0045] Waxes:
[0046] According to the stipulation of the German Society for Fat
Economic (Fette, Seifen, Anstrichmittel, 76, 135 [1974]), as a rule
the mechanicophysical properties of the waxes, which are decisive
for their use, are used for the characterization of the term "wax",
while the respective chemical composition remains unconsidered in
the determination of the term.
[0047] "Wax" is--similarly to "resin"--a collective description of
a number of natural or synthetically obtained substances, which as
a rule have the following properties: kneadable at 20.degree. C.,
solid to friably hard, coarse- to fine-crystalline, transparent to
opaque, but not glassy, melting above 40.degree. C. without
decomposition, even slightly above the melting point of
comparatively low viscosity and non-thread-drawing, strongly
temperature-dependent consistency and tolerability and polishable
under slight pressure. In borderline cases, if more than one of the
abovementioned properties is not fulfilled in a substance, it is
not a wax within the meaning of this definition. Waxes differ from
similar synthetic or natural products (e.g. resins, plastic
materials etc.) mainly in that as a rule they turn into the molten,
low-viscosity state approximately between 50 and 90.degree. C., in
exceptional cases also up to approximately 200.degree. C., and are
virtually free of ash-forming compounds.
[0048] Oil thickeners are substances which, for example, are
capable of absorbing liquid oils with formation of homogeneous,
viscous and colloidal solutions. They are added to cosmetic or
dermatological preparations during their preparation or processing
in order to thicken the fatty phase.
[0049] Waxes and/or oil thickeners within the meaning of the
present invention are compounds which are characterized in that,
together with the other oil components of the preparations
according to the invention (such as, for example, polar, liquid
compounds, UV filters and their solvents etc.), they form a
material which is pasty (viscous) and spreadable at room
temperature, which has a viscosity of more than 5000 mPa.multidot.s
at 20.degree. C.
[0050] Those advantageous according to the invention are, for
example, natural waxes of animal and vegetable origin, such as, for
example, beeswax, China wax, bumblebee wax and other insect waxes,
in particular those mentioned below.
[0051] Beeswax, for example, is a secretion product from glands of
honeybees, which they use for building honeycombs. Yellow (Cera
flava), brown or red so-called raw wax is obtainable, for example,
by melting the combs freed from the honey by centrifuging,
separating the melt from solid impurities and allowing the raw wax
thus obtained to solidify. The raw wax can be bleached completely
white (Cera alba) by treatment with oxidizing agents.
[0052] Beeswax consists of the readily alcohol-soluble cerin, a
mixture of cerotic acid CH.sub.3(CH.sub.2).sub.24COOH and melissic
acid CH.sub.3(CH.sub.2).sub.28COOH and of an ester mixture called
myricin consisting of about 70 esters of C.sub.16- to
C.sub.36-acids and C.sub.24- to C.sub.36-alcohols. Essential
constituents of beeswax are myricyl palmitate, myricyl cerotinate
and paraffin.
[0053] Other insect waxes such as, for example, bumblebee wax,
shellac wax or China wax are essentially mixtures of various
esters. China wax, for example, is deposited or produced in China
and Japan from the Chinese wax scale (Coccus ceriferus) living on
the Chinese ash and the scale species Ceroplastes ceriferus and
Ericerus pela. It is scraped from the trees and purified by
remelting in boiling water. The main constituent of China wax is
the cerotic acid ester of ceryl alcohol.
[0054] Shellac wax is obtained from lac, the secretion of the
female lac insects (Kerria lacca), which live in huge colonies (lac
is derived from the Hindi word "Lakh" for 100,000) on trees and
shrubs in Southern Asia (India, Burma, Southern China). The shellac
wax accessible by solvent extraction contains myricyl alcohol,
melissic acid and other wax alcohols and acids or their esters as
essential constituents.
[0055] Plant waxes are also advantageous within the meaning of the
present invention. Those which can preferably be used are cuticular
waxes of lower and higher plants, algae, lichens, mosses and fungi,
such as, for example, candelilla wax, carnauba wax, Japan wax,
esparto grass wax, cork wax, rice wax, sugar cane wax, fruit waxes,
e.g. apple wax, flower waxes, leaf waxes from conifers, coffee wax,
flax wax, sesame wax, jojoba oil and such like.
[0056] Candelilla waxes, for example, are brownish to yellowish
brown, hard waxy materials which are soluble in lipophilic
solvents. Candelilla wax contains odd-number aliphatic hydrocarbons
(about 42%), esters (about 39%), wax acids and wax alcohols. It can
be obtained, for example, from the comminuted, fleshy leaves of a
thornless spurge species (Euphorbia cerifera) by boiling with
aqueous sulphuric acid.
[0057] Carnauba wax is a yellowish, greenish or dark-grey material
which can be obtained in various qualities, obtained by selection
from the leaves of the Brazil fan palm Copernicia prunifera or
carnauba palm (Carnauba cerifera) by, for example, brushing the wax
dust from the withered fronds, melting it and filtering it and,
after solidification, breaking it into pieces. Carnauba wax can be
lightened by bleaching. It contains about 85% of esters, in each
case approximately 2-3% of free wax acids (carnaubic, behenic,
lignoceric, melissic and cerotinic acid), long-chain alcohols,
diols and saturated hydrocarbons.
[0058] Japan wax (also: Cera japonica) is colourless or yellowish,
pure plant fat, which can be obtained, for example, in Japan from
the fruits of a tree-like sumac plant (Rhus succedanea) by boiling.
The main constituents of Japan wax are glyceryl palmitate and
esters of japonic acid (heneicosanedioic acid,
C.sub.21H.sub.40O.sub.4), phellogenic acid (docosanedioic acid,
C.sub.22H.sub.42O.sub.4) and of tricosanedioic acid
(C.sub.23H440.sub.4).
[0059] Esparto wax is obtained as a by-product in pulp and paper
manufacture from the esparto grass (Graminaceae) indigenous to
Mediterranean countries. It consists to about 15 to 17% of wax
acids (e.g. cerotic and melissic acid), to 20 to 22% of alcohols
and hydrocarbons and to 63 to 65% of esters.
[0060] Particularly advantageous natural waxes within the meaning
of the present invention are those obtained, for example, under the
tradenames Permulgin 1550 and Permulgin 4002 from KOSTER KEUNEN and
those obtainable under the tradenames Schellack Wachs 7302 L and
Candellila Wachs 2039 L from the KAHL wax refinery.
[0061] Chemically modified waxes and synthetic waxes are
furthermore advantageous according to the invention. Preferred
modified waxes are, for example, beeswax esters, in particular the
alkyl beeswaxes obtainable from KOSTER KEUNEN under the tradenames
BW Ester BW 67, BW Ester BW 80.
[0062] Preferred synthetic waxes are, for example, that obtainable
under the tradename beeswax component B 85 from SCHLICKUM and
silicone-based waxes, such as, for example,
dialkoxydimethylpolysiloxanes, which are distinguished by the
following structure 1
[0063] in which x is a number between 18 and 24. Behenoxy
dimethicone, for which x from the above structural formula is 21
and which is obtainable under the tradename Abil.RTM. Wax 2440 from
Th. Goldschmidt AG is particularly advantageous. A silicone-based
wax, which is obtainable under the tradename Siliconyl Beeswax from
KOSTER KEUNEN is furthermore preferred according to the
invention.
[0064] Further advantageous synthetic waxes are certain fatty acids
and/or fatty acid mixtures, for example C.sub.16-36-fatty acids, in
particular those which are obtainable under the tradename Syncrowax
AW1C from Croda GmbH.
[0065] Ester waxes which are esters of
[0066] 1. a saturated and/or unsaturated, branched and/or
unbranched mono- and/or dicarboxylic acid having 12 to 40 carbon
atoms and
[0067] 2. a saturated and/or unsaturated, branched and/or
unbranched alcohol having 12 to 40 carbon atoms
[0068] are moreover advantageous within the meaning of the present
invention.
[0069] Ester waxes which are selected from the group listed below
are particularly advantageous:
1 Ester wax Tradename Obtainable from Myristyl myristate Cetiol MM
Henkel KGaA Cetyl palmitate Cutina OP Henkel KGaA C.sub.14-34 alkyl
stearate Kesterwachs K 76 H KOSTER KEUNEN C.sub.20-40 dialkyl
dimerate Kesterwachs K 80 D KOSTER KEUNEN Ditetracosanyl dimerate
Kesterwachs K 70D KOSTER KEUNEN C.sub.16-38 alkyl hydroxy-
Kesterwachs K 80P KOSTER KEUNEN stearoyl stearate C.sub.20-40 alkyl
stearoyl Kesterwachs K 80P-VS KOSTER KEUNEN stearoyl stearate
C.sub.20-40 alkyl stearate Kesterwachs K 82 KOSTER KEUNEN
Hydroxystearyl hydroxy- Elfacos C26 AKZO NOBEL stearate
[0070] Esters of glycol, in particular glycol esters of lignoceric
acid (CH.sub.3(CH.sub.2).sub.22COOH), of cerotic acid
(CH.sub.3(CH.sub.2).sub.- 24COOH) and/or of montanic acid
(CH.sub.3(CH.sub.2).sub.26COOH) are furthermore advantageous.
Glycol esters of montanic acid (CH.sub.3(CH.sub.2).sub.26COOH) are
very particularly advantageous within the meaning of the present
invention. An advantageous glycol montanate is obtainable, for
example, in a mixture with a butylene glycol montanate under the
tradename Wax E Pharma from Clariant.
[0071] It is furthermore advantageous to select the wax components
from the group consisting of the glycerides, in particular from the
group consisting of the triglycerides. The glycerides and
triglycerides listed below are particularly advantageous:
2 Glyceride Tradename Obtainable from C.sub.16-18 triglyceride
Cremeol Aarhus Oliefabrik HF-52-SPC Glyceryl hydroxystearate
Naturchem GMHS Rahn Hydrogenated cocoa glycerides Softisan 100 Huls
AG Caprylic/capric/isostearic/ Softisan 649 Dynamit Nobel adipic
triglyceride C.sub.18-36 triglyceride Syncrowax HGLC Croda GmbH
Glyceryl tribehenate Syncrowax HRC Croda GmbH Glyceryl
tri(12-hydroxystearate) Thixicin R Rheox/NRC Hydrogenated castor
oil Cutina HR Henlek KGaA C.sub.16-24 triglyceride Cremeol Aarhus
Oliefabrik HF-62-SPC
[0072] Shea butter, also called karite oil or galam butter (CAS No.
68920-03-6), is also particularly preferred. Shea butter is the fat
of the seeds or kernels of the plant Butyrospermum Parkii belonging
to the family of the Sapotaceae, which consists to approximately 34
to 45% by weight of solid fatty acids (principally stearic acid)
and to approximately 50 to 60% by weight of liquid fatty acids
(principally comprising oleic acid).
[0073] According to the invention, the waxes are furthermore
preferably selected from the group consisting of the saturated
and/or unsaturated, branched and/or unbranched fatty alcohols
having 14 to 40 carbon atoms; behenyl alcohol (C.sub.22H.sub.45OH),
cetearyl alcohol [a mixture of cetyl alcohol (C.sub.16H.sub.13OH)
and stearyl alcohol (C.sub.18H.sub.37OH)],
cetylarachidol[2-hexadecyl-1-eicosanol(C.sub.36H.s- ub.73OH], and
or 2-tetradecyloctadecanol (C.sub.32H.sub.65OH) are particularly
preferred. Advantageous embodiments of the two last-mentioned fatty
alcohols are obtainable from Condea under the tradenames Isofol 36
and Isofol 32.
[0074] Within the meaning of the present invention, oil thickeners
are selected, for example, from the group consisting of the metal
soaps. Metal soaps are the salts of higher fatty acids, resin acids
and naphthenic acids (stearates, palmitates, oleates, linoleates,
resinates, laurates, octanoates, ricinoleates, 12-hydroxystearates,
naphthenates, tallates and the like) with the exception of the
sodium and potassium salts, that is, for example, the salts of the
metals aluminium, barium, calcium, cadmium, cobalt, chromium,
copper, iron, lithium, magnesium, manganese, nickel, lead, tin,
strontium and zinc.
[0075] Of course, the person skilled in the art knows that among
the metal soaps are some which would be fundamentally suitable for
the realization of the present invention, but which should
nevertheless be dispensed with because of harmful action on the
skin or other concomitant factors. According to the CIR panel, a
committee which checks whether adequate toxicity data are available
for substances which are employed in the cosmetic industry (CIR:
Cosmetic Ingredient Review), for example, lithium, aluminium,
calcium and zinc stearates are to be regarded as harmless in the
doses which are customarily used for the preparation of cosmetic
compositions. In addition to the requirements of various
pharmaceutical regulations, magnesium stearate also meets the
demands which foodstuffs quality sets.
[0076] For the sake of simplicity, reference is made to the
relevant regulations for unambiguous differentiation between
cosmetically harmful and harmless substances (e.g. Cosmetics
decree, Food and Drugs Act, official pharmacopoeia, publications of
the CIR panel etc.).
[0077] Aluminium stearate and magnesium stearate are particularly
preferred within the meaning of the present invention.
[0078] The oil thickener(s) selected from the group consisting of
the layered silicates, in particular from the group consisting of
the bentonites and hectorites, is/are furthermore advantageous.
Bentonites are clays and rocks which contain smectites, especially
montmorillonite, as the main minerals. Modified bentonites and
hectorites, for example those whose organophilicity has been
increased by reaction with quaternary ammonium compounds, are
particularly preferred within the meaning of the present invention.
These types of bentonites are also designated as organophilic
bentonites or alternatively bentones. Those which are very
particularly preferred are stearalkonium hectorite, a reaction
product of hectorite and stearalkonium chloride
(benzyldimethylstearylammonium chloride), and quaternium-18
hectorite, a reaction product of hectorite and a quaternary
ammonium salt, which are obtainable from Nordmann & Rassmann,
for example, under the tradenames Bentone 27 and Bentone 38.
[0079] The total amount of one or more waxes and/or oil thickeners
in the finished cosmetic or dermatological preparations is
advantageously chosen to be in the range of 0.5 to 20.0% by weight,
preferably between 1.0 and 5.0% by weight, based on the total
weight of the preparations.
[0080] It is also advantageous, although not obligatory, for the
Pickering emulsions according to the invention to comprise other
auxiliaries which can contribute to reducing or preventing a dull
or dry feel on the skin following their application, where it is
possible that the main purpose of these substances is a different
one. Preferably, these substances are, for example, chosen from the
group of unsymmetrically substituted s-triazine derivatives,
cyclodextrins, film formers and polymeric moisturizers, it being
possible for these substances to be present either individually or
in a mixture.
[0081] The cosmetic properties of the Pickering emulsions according
to the invention can additionally, for example, be further improved
by also using oils in the oil phase which have a viscosity of less
than 30 mPa.s, in particular of less than 20 mPa.s (determined
using a rheometer from Contraves (Rheomat 108E) at a shear gradient
of 500/s and a temperature of 25.degree. C.).
[0082] Microfine Particles:
[0083] The amphiphilic character of the microfine particles
according to the invention is evident, for example, from the fact
that they are dispersible both in water and in oil.
[0084] It is advantageous to choose the average particle diameter
of the particles used to be between 1 nm and 200 nm, particularly
advantageously between 5 nm and 100 nm.
[0085] It is also advantageous to choose the concentration of all
amphiphilic particles according to the invention to be greater than
0.1% by weight, particularly advantageously between 0.1% by weight
and 30% by weight, based on the total weight of the
preparations.
[0086] For the purposes of the present invention, advantageous
particles are all those which are suitable for stabilizing
Pickering W/O emulsions or Pickering O/W emulsions. It is
essentially insignificant for the present invention in which of the
potentially naturally occurring modifications the particles are
present.
[0087] To stabilize the Pickering emulsions, preference is given to
using untreated, virtually pure pigment particles, in particular
those which can be used as dyes in the food industry and/or as
absorbers of UV radiation in sunscreens. Examples of advantageous
pigments are the zinc oxide pigments available from Merck which are
available under the tradenames Zinkoxid neutral from Haarmann &
Reimer or NanoX from Harcros Chemical Group.
[0088] For the purposes of the present invention, Pickering
emulsions are likewise advantageously stabilized by inorganic
pigments which have been surface-treated ("coated") to repel water,
where at the same time the intention is to form or retain the
amphiphilic character. This surface-treatment can consist in
providing the pigments with a thin hydrophobic layer by processes
known per se.
[0089] One such process, which is described below using titanium
dioxide as an example, consists in, for example, producing the
hydrophobic surface layer according to the following reaction
n TiO.sub.2+m(RO).sub.3Si--R'.fwdarw.n TiO.sub.2 (surf.).
[0090] n and m are arbitrary stoichiometric parameters, and R and
R' are the desired organic radicals. Particularly advantageous are
TiO.sub.2 pigments, for example those coated with aluminium
stearate, available under the tradename MT 100 T from TAYCA.
[0091] A further advantageous coating of the inorganic pigments
consists of dimethylpolysiloxane (also: dimethicone), a mixture of
completely methylated, linear siloxane polymers which are
terminally blocked with trimethylsiloxy units. For the purposes of
the present invention, particularly advantageous pigments are zinc
oxide pigments which are coated in this way.
[0092] Also advantageous is a coating of the inorganic pigments
with a mixture of dimethylpolysiloxane, in particular
dimethylpolysiloxane having an average chain length of from 200 to
350 dimethylsiloxane units, and silica gel, which is also referred
to as simethicone. It is particularly advantageous if the inorganic
pigments have been additionally coated with aluminium hydroxide or
hydrated aluminium oxide (also: alumina, CAS No.: 1333-84-2).
Particularly advantageous are titanium dioxides which have been
coated with simethicone and alumina, it being possible for the
coating to also comprise water. One example thereof is the titanium
dioxide available under the tradename Eusolex T2000 from Merck.
[0093] For the purposes of the present invention it is also
advantageous to use a mixture of different pigment types either
within a crystal, for example as mixed iron oxide, or by
combination of two or more pigment types within a preparation.
[0094] The Pickering emulsions are also preferably stabilized by
boron nitride particles, for example by the boron nitrides listed
below:
3 Trade name Available from Boron Nitride Powder Advanced Ceramics
Boron Nitride Powder Sintec Keramik Ceram Blanche Kawasaki HCST
Boron Nitride Stark Trs BN .RTM. Carborundum Wacker-Bornitrid BNP
Wacker-Chemie
[0095] It is advantageous to choose the average particle diameter
of the boron nitride particles used to be less than 20 .mu.m,
particularly advantageously less than 15 .mu.m.
[0096] For the purposes of the present invention, Pickering
emulsions are likewise advantageously stabilized by boron nitride
particles which have been surface-treated ("coated") to repel
water, where at the same time the intention is to form or retain
the amphiphilic character.
[0097] An advantageous coating of the boron nitride particles
consists of dimethylpolysiloxane (dimethicone). The boron nitride
particles treated with dimethicone and available from Carborundum
under the tradename Trs BN.RTM. UHP 1106 are advantageous, for
example.
[0098] Also advantageous is a coating of the boron nitride
particles with polymethylhydrogensiloxane, a linear polysiloxane
which is also referred to as methicone. Advantageous boron nitride
particles treated with methicone are, for example, those available
from Carborundum under the tradename Trs BN.RTM. UHP 1107.
[0099] It is also advantageous to stabilize the Pickering emulsions
according to the invention using microfine polymer particles.
[0100] For the purposes of the present invention, examples of
advantageous microfine polymer particles are polycarbonates,
polyethers, polyethylenes, polypropylenes, polyvinyl chloride,
polystyrene, polyamides, polyacrylates and the like.
[0101] Advantageous according to the invention are, for example,
microfine polyamide particles which are available under the
tradename SP-500 from TORAY. Also advantageous are polyamide 6
(also: nylon 6) and polyamide 12 (also: nylon 12) particles.
Polyamide 6 is the polyamide formed from .epsilon.-aminocaproic
acid (6-aminohexanoic acid) or .epsilon.-caprolactam
[poly(.epsilon.-caprolactam)], and polyamide 12 is a
poly(.epsilon.-laurolactam) from .epsilon.-laurolactam. For the
purposes of the present invention, Orgasol.RTM. 1002 (polyamide 6)
and Orgasol.RTM. 2002 (polyamide 12) from ELF ATOCHEM, for example,
are advantageous.
[0102] Other advantageous polymer particles are microfine
polymethacrylates. Such particles are available, for example, under
the tradename POLYTRAP.RTM. from DOW CHEMICAL.
[0103] It is particularly advantageous, but not obligatory, if the
microfine polymer particles used have been surface-coated. This
surface-treatment can consist in providing the pigments with a thin
hydrophilic layer by processes known per se. Advantageous coatings
consist, for example, of TiO.sub.2, ZrO.sub.2 or also other
polymers, such as, for example, polymethyl methacrylate.
[0104] Particularly advantageous microfine polymer particles for
the purposes of the present invention are also obtainable by the
process, described in U.S. Pat. No. 4,898,913, for the hydrophilic
coating of hydrophobic polymer particles.
[0105] It is advantageous to choose the average particle diameter
of the microfine polymer particles used to be less than 100 .mu.m,
particularly advantageously less than 50 .mu.m. In this connection,
it is essentially insignificant in which form (platelets, rods,
spherules, etc.) the polymer particles used are present.
[0106] In addition, it is advantageous to stabilize the Pickering
emulsions according to the invention using modified
polysaccharides.
[0107] For the purposes of the present invention, modified
polysaccharides are, for example, obtainable by reaction of starch
with mono-, bi- or polyfunctional reagents or oxidizing agents in
reactions which proceed in a largely polymer-analogous manner.
[0108] Such reactions are based essentially on modifications of the
hydroxyl groups of the polyglucans by etherification,
esterification or selective oxidation. This produces, for example,
so-called starch ethers and starch esters of the general structural
formula 2
[0109] in which R can, for example, be a hydrogen and/or an alkyl
and/or an aralkyl radical (in the case of starch ethers) or a
hydrogen and/or an organic and/or inorganic acid radical (in the
case of starch esters). Starch ethers and starch esters are
advantageous, modified polysaccharides for the purposes of the
present invention.
[0110] Particularly advantageous starch ethers are, for example,
those which are obtainable by etherification of starch with
tetramethylolacetylenediurea and which are referred to as
non-mucilaginous starch (nonswelling starch).
[0111] Also particularly advantageous are starch esters and salts
thereof, for example the sodium and/or aluminium salts of
half-esters of starch which have low degrees of substitution, in
particular sodium starch n-octenyl succinate of the structural
formula (II) in which R is characterized by the following structure
3
[0112] and which is available, for example, under the tradename
Amiogum.RTM. 23 from CERESTAR, and aluminium starch octenyl
succinates, in particular those available under the tradenames Dry
Flo.RTM. Elite LL and Dry Flo.RTM. PC from CERESTAR.
[0113] It is advantageous to choose the average particle diameter
of the modified polysaccharide used to be less than 20 .mu.m,
particularly advantageously less than 15 .mu.m.
[0114] The list of given modified polysaccharides which are able to
stabilize Pickering emulsions according to the invention is of
course not intended to be limiting. For the purposes of the present
invention, modified polysaccharides are obtainable in a large
number of ways known per se, both of a chemical and a physical
nature.
[0115] The abovementioned amphiphilic particles are outstandingly
suitable both for the stabilization of W/O Pickering emulsions and
for the stabilization of O/W Pickering emulsions. Microfine
particles according to the invention are mentioned below which
advantageously in particular stabilize one of the two emulsion
types W/O or O/W.
[0116] W/O Pickering Emulsions:
[0117] The water phase proportion in the W/O Pickering emulsions
according to the invention is preferably selected from the range of
0.5 to 75% by weight, based on the total weight of the
formulations.
[0118] Magnesium silicates (also: talc), for example those
obtainable under the tradename Talkum Micron from Grolmann, in
particular are also advantageous for the stabilization of W/O
Pickering emulsions.
[0119] O/W Pickering Emulsions:
[0120] The fatty phase fraction of the O/W Pickering emulsions
according to the invention is preferably selected from the range of
0.5 to 75% by weight, based on the total weight of the
formulations.
[0121] Untreated, almost pure pigment particles, for example
titanium dioxide pigments, in particular those which are obtainable
under the tradename KRONOS.RTM. 1171 (TiO.sub.2) from Kronos Titan
are also particularly advantageous for the stabilization of O/W
Pickering emulsions within the meaning of the present
invention.
[0122] O/W Pickering emulsions within the meaning of the present
invention are furthermore particularly advantageously stabilized by
metal oxide particles which are coated with aluminium hydroxide
and/or silicon dioxide. Advantageous embodiments are, for example,
titanium dioxide particles, which are obtainable under the name
EUSOLEX.RTM. TA from Merck.
[0123] It is furthermore advantageous, although not obligatory, to
combine the microfine particles according to the invention with
further amphiphilic particles which can optionally also contribute
to the stabilization of the Pickering emulsions.
[0124] Such particles are, for example, titanium dioxide pigments
which are coated with octylsilanol, and/or silicon dioxide
particles which have a water-repellent treatment on the surface.
Suitable silicon dioxide particles are, for example, spherical
polyalkylsilsesquioxane particles, such as are mentioned in
European Laid-Open Specification 0 686 391. Such
polyalkylsilsesquioxane particles are obtainable, for example, from
Degussa under the tradenames Aerosil R972 and Aerosil 200V.
Suitable titanium dioxide particles are likewise obtainable from
Degussa under the tradename T805.
[0125] The Pickering emulsions according to the invention can serve
as a base for cosmetic or dermatological formulations. These can be
combined in the customary manner and serve, for example, for the
treatment and care of the skin, as a lipcare product, as a
deodorant product and as a make-up or make-up removal product in
decorative cosmetics or as a sunscreen preparation. For use, the
cosmetic and dermatological preparations according to the invention
are applied to the skin in adequate amount in the manner customary
for cosmetics.
[0126] Accordingly, cosmetic or topical dermatological compositions
within the meaning of the present invention, depending on their
make-up, can be used, for example, as a skin-protection cream,
cleansing milk, sunscreen lotion, nutrient cream, day cream or
night cream, etc. It is optionally possible and advantageous to use
the compositions according to the invention as a base for
pharmaceutical formulations.
[0127] The cosmetic and dermatological preparations according to
the invention can contain cosmetic auxiliaries, such as are
customarily used in such preparations, e.g. preservatives,
bactericides, perfumes, substances for preventing foaming,
colorants, pigments which have a colouring action, thickening
agents, emollient, moisturizing and/or humectant substances, fats,
oils, waxes or other customary constituents of a cosmetic or
dermatological formulation such as alcohols, polyols, polymers,
foam stabilizers, electrolytes, organic solvents or silicone
derivatives.
[0128] Pickering emulsions according to the invention can also
contain thickening agents in order to improve the tactile
properties of the emulsion.
[0129] In particular, the Pickering emulsions according to the
invention can also contain antioxidants. According to the
invention, favourable antioxidants which can be used are all
antioxidants suitable or customary for cosmetic and/or
dermatological applications.
[0130] Advantageously, the antioxidants are selected from the group
consisting of amino acids (e.g. glycine, histidine, tyrosine,
tryptophan) and their derivatives, imidazoles (e.g. urocanic acid)
and their derivatives, peptides, such as D,L-carnosine,
D-carnosine, L-carnosine and their derivatives (e.g. anserine),
carotenoids, carotenes (e.g. .alpha.-carotene, .beta.-carotene,
lycopene) and their derivatives, chlorogenic acid and its
derivatives, lipoic acid and its derivatives (e.g. dihydrolipoic
acid), aurothioglucose, propylthiouracil and other thiols (e.g.
thioredoxin, glutathione, cysteine, cystine, cystamine and their
glycosyl, N-acetyl, methyl, ethyl, propyl, amyl, butyl and lauryl,
palmitoyl, oleyl, .gamma.-linoleyl, cholesteryl and glyceryl
esters) and their salts, dilauryl thiodipropionate, distearyl
thiodipropionate, thiodipropionic acid and its derivatives (esters,
ethers, peptides, lipids, nucleotides, nucleosides and salts) and
sulphoximine compounds (e.g. buthionine sulphoximine, homocysteine
sulphoximine, buthionine sulphone, penta-, hexa- and heptathionine
sulphoximine) in very small tolerable doses (e.g. pmol to
.mu.mol/kg), furthermore (metal) chelators (e.g. .alpha.-hydroxy
fatty acids, palmitic acid, phytic acid, lactoferrin),
.alpha.-hydroxy acids (e.g. citric acid, lactic acid, malic acid),
humic acid, bile acid, bile extracts, bilirubin, biliverdin, EDTA,
EGTA and their derivatives, unsaturated fatty acids and their
derivatives (e.g. .gamma.-linolenic acid, linoleic acid, oleic
acid), folic acid and its derivatives, ubiquinone and ubiquinol and
their derivatives, vitamin C and derivatives (e.g. ascorbyl
palmitate, Mg ascorbyl phosphate, ascorbyl acetate), tocopherols
and derivatives (e.g. vitamin E acetate), vitamin A and derivatives
(vitamin A palmitate) and coniferyl benzoate of benzoin, rutic acid
and its derivatives, .alpha.-glycosylrutin, ferulic acid,
furfurylideneglucitol, carnosine, butylhydroxytoluene,
butylhydroxyanisole, nordihydroguaiac acid, nordihydroguaiaretic
acid, trihydroxybutyrophenone, uric acid and its derivatives,
mannose and its derivatives, zinc and its derivatives (e.g. ZnO,
ZnSO.sub.4), selenium and its derivatives (e.g. selenomethionine),
stilbenes and their derivatives (e.g. stilbene oxide,
trans-stilbene oxide), and the derivatives suitable according to
the invention (salts, esters, ethers, sugars, nucleotides,
nucleosides, peptides and lipids) of these said active
compounds.
[0131] The amount of the abovementioned antioxidants (one or more
compounds) in the preparations according to the invention is
preferably from 0.001 to 30% by weight, particularly preferably
from 0.05-20% by weight, in particular 1-10% by weight, based on
the total weight of the preparation.
[0132] If vitamin E and/or its derivatives are the antioxidant(s),
it is advantageous to select their respective concentrations from
the range of 0.001-10% by weight, based on the total weight of the
formulation.
[0133] If vitamin A, or vitamin A derivatives, or carotenes or
their derivatives are the antioxidant(s), it is advantageous to
select their respective concentrations from the range of 0.001-10%
by weight, based on the total weight of the formulation.
[0134] Cosmetic and dermatological preparations which are present
in the form of a sunscreen composition are also favourable. These
preferably contain at least one UV-A filter substance and/or at
least one UV-B filter substance and/or at least one further
inorganic pigment from the group consisting of the oxides of iron,
zirconium, silicon, manganese, aluminium, cerium and mixtures
thereof and also modifications in which the oxides are the active
agents.
[0135] However, it is also advantageous within the meaning of the
present invention to make available those cosmetic and
dermatological preparations whose main purpose is not protection
from sunlight, but which nevertheless contain substances which
protect against UV. Thus, UV-A and UV-B filter substances are
usually incorporated, for example, into day creams.
[0136] Advantageously, preparations according to the invention can
contain substances which absorb UV radiation in the UV-B range, the
total amount of filter substances being, for example, 0.1% by
weight to 30% by weight, preferably from 0.5 to 10% by weight, in
particular 1.0 to 6.0% by weight, based on the total weight of the
preparations, in order to make available cosmetic preparations
which protect the hair or the skin from the entire range of
ultraviolet radiation.
[0137] If the emulsions according to the invention contain UV-B
filter substances, these can be oil-soluble or water-soluble.
Oil-soluble UV-B filters which are advantageous according to the
invention are, for example:
[0138] 3-benzylidenecamphor derivatives, preferably
3-(4-methylbenzylidene)camphor, 3-benzylidenecamphor;
[0139] 4-aminobenzoic acid derivatives, preferably 2-ethylhexyl
4-dimethylaminobenzoate, amyl 4-dimethylaminobenzoate;
[0140] esters of cinnamic acid, preferably 2-ethylhexyl
4-methoxycinnamate, isopentyl 4-methoxycinnamate;
[0141] esters of salicylic acid, preferably 2-ethylhexyl
sialicylate, 4-isopropylbenzyl salicylate, homomenthyl
salicylate,
[0142] derivatives of benzophenone, preferably
2-hydroxy-4-methoxybenzophe- none,
2-hydroxy-4-methoxy4'-methylbenzophenone,
2,2'-dihydroxy-4-methoxybe- nzophenone;
[0143] esters of benzalmalonic acid, preferably di(2-ethylhexyl)
4-methoxybenzalmalonate,
[0144] triazine derivatives which are symmetrical with respect to
the C.sub.3 axis of the triazine parent structure, preferably
tris(2-ethylhexyl)
4,4',4"-(1,3,5-triazine-2,4,6-triyltriimino)trisbenzoa- te,
[0145] benzotriazole derivatives, preferably
2,2'-methylenebis(6-(2H-benzo-
triazole-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol)
[0146] and UV filters bonded to polymers.
[0147] Advantageous water-soluble UV-B filters are, for
example:
[0148] salts of 2-phenylbenzimidazole-5-sulphonic acid such as its
sodium, potassium or its triethanolammoniun salt, and the sulphonic
acid itself;
[0149] sulphonic acid derivatives of benzophenones, preferably
2-hydroxy-4-methoxybenzophenone-5-sulphonic acid and its salts;
[0150] sulphonic acid derivatives of 3-benzylidenecamphor, such as,
for example, .sup.4-(2-oxo-3-bornylidenemethyl)benzenesulphonic
acid, 2-methyl-5-(2-oxo-3-bornylidenemethyl)sulphonic acid and its
salts.
[0151] The list of the UV-B filters mentioned, which can be used in
the Pickering emulsions according to the invention, should, of
course, be non-limiting.
[0152] It can also be advantageous in Pickering emulsions according
to the invention to use UV-A filters which have hitherto be
customarily contained in cosmetic preparations. These substances
are preferably derivatives of dibenzoylmethane, in particular
1-(4'-tert-butylphenyl)-3-- (4'-methoxyphenyl)propane-1,3-dione and
1-phenyl-3-(4'-isopropylphenyl)pro- pane-1,3-dione.
[0153] Other advantageous UV-A filter substances are
phenylene-1,4-bis(2-benzimidazyl)-3,3'-5,5'-tetrasulphonic acid:
4
[0154] and its salts, particularly the corresponding sodium,
potassium or triethanolammonium salts, in particular the bis-sodium
salt of phenylene-1,4-bis(2-benzimidazyl)-3,3'-5,5'-tetrasulphonic
acid: 5
[0155] and 1,4-di(2-oxo-10-sulfo-3-bornylidenemethyl)benzene and
salts thereof (particularly the corresponding 10-sulfato compounds,
in particular the corresponding sodium, potassium or
triethanolammonium salt), which is also referred to as
benzene-1,4-di(2-oxo-3-bornylidenemet- hyl-10-sulphonic acid) and
is characterized by the following structure: 6
[0156] Preparations which contain UV-A filters are also a subject
of the invention. The amounts used for the UV-B combination can be
employed.
[0157] Preparations according to the invention can also be
advantageously used as bases for cosmetic deodorants and
antiperspirants, so that a particular embodiment of the present
invention relates to Pickering emulsions as bases for cosmetic
deodorants.
[0158] Cosmetic deodorants are used to control body odour which
arises when fresh perspiration, which is in itself odourless, is
decomposed by microorganisms. Customary cosmetic deodorants are
based on various modes of action.
[0159] In antiperspirants, astringents, mainly aluminium salts,
such as aluminium hydroxychloride (aluminium chlorohydrate), reduce
the formation of perspiration.
[0160] The use of antimicrobial substances in cosmetic deodorants
can reduce the bacterial flora of the skin. In an ideal situation,
only the microorganisms which cause the odour should be effectively
reduced. The flow of perspiration itself is not influenced as a
result, and in ideal circumstances, only microbial decomposition of
perspiration is stopped temporarily.
[0161] The combination of astringents and antimicrobial active
substances in one and the same composition is also common.
[0162] All active ingredients common for deodorants or
antiperspirants can advantageously be used, for example odour
concealers, such as customary perfume constituents, odour
absorbers, for example the phyllosilicates described in Laid-open
Patent Specification DE 40 09 347, of these in particular
montmorillonite, kaolinite, illite, beidellite, nontronite,
saponite, hectorite, bentonite, smectite, and also, for example,
zinc salts of ricinoleic acid. Antibacterial agents are also
suitable to be incorporated into the novel W/O emulsion sticks.
Advantageous substances are, for example,
2,4,4'-trichloro-2'-hydroxy diphenyl ether (irgasan),
1,6-di(4-chlorophenylbiguanido)hexane (chlorhexidine),
3,4,4'-trichlorocarbanilide, quaternary ammonium compounds, oil of
cloves, mint oil, thyme oil, triethyl citrate, farnesol
(3,7,11-trimethyl-2,6,10-dodecatrien-1-ol) and also the active
ingredients or active ingredient combinations described in the
Laid-open Patent Specifications DE-A-37 40 186, DE-A-39 38 140,
DE-A-42 04 321, DE-A-42 29 707, DE-A-43 09 372, DE-A-44 11 664,
DE-A-195 41 967, DE-A-195 43 695, DE-A-195 43 696, DE-A-195 47 160,
DE-A-196 02 108, DE-A-196 02 110, DE-A-196 02 111, DE-A-196 31 003,
DE-A-196 31 004 and DE-A-196 34 019, and the Patent SSpecifications
DE-42 29 737, DE-42 37 081, DE-43 24 219, DE-44 29 467, DE-44 23
410 and DE-195 16 705. Sodium hydrogencarbonate can also be used
advantageously.
[0163] The list of specified active ingredients and active
ingredient combinations is of course not intended to be
limiting.
[0164] The amount of antiperspirant active ingredients or
deodorants (one or more compounds) in the preparations is
preferably from 0.01 to 30% by weight, particularly preferably from
0.1 to 20% by weight, in particular 1-10% by weight, based on the
total weight of the preparation.
[0165] The examples below serve to illustrate the present invention
without limiting it. The numerical values in the examples are
percentages by weight, based on the total weight of the respective
preparations.
4 Examples 1 2 3 4 5 6 W/O W/O W/O O/W O/W O/W Titanium dioxide
(Eusolex 2 4 6 3 5 2 T2000) Zinc oxide 5 4 4 Titanium dioxide
(Titandioxid 2 T805) Silica (Aerosil R972) 1 0.5 Talc (Talkum
Micron) 0.5 Boron nitride 2 Sodium maize starch 0.5 1
n-octenylsuccinate Hydroxystearyl hydroxy- 2 2 stearate (Elfacos
C26) C.sub.20-40-alkyl stearate 1 1 2 (Kesterwachs K82)
C.sub.16-38-alkylhydroxystearoyl 2 3 5 stearate (Kesterwachs K80P)
Behenoxy dimethicone 5 5 (Abil Wax 2440) Polyisobutene (Rewopal 5
PIB 1000) Caprylic/capric triglyceride 5 5 5 20 20 20
Octyldodecanol 5 5 15 15 Mineral oil 10 10 20 Butylene glycol 10 10
20 7 caprylate/caprate C.sub.12-15-alkyl benzoate 10 10 10 5 15
Dimethicone 2 3 Dicaprylyl ether (Cetiol OE) 5 Hydrogenated
polyisobutene 2 (Polysynlan) Methylbenzylidenecamphor 3 4
Octyltriazone 1 4 Dibenzoylmethane 2 2 Dioctylbutamidotriazone 2
(UVASORB HEB) Preservative 0.5 0.5 0.5 0.5 0.5 0.5 Glycerol 5 10 3
5 5 5 Biosaccharide gel 5 (Fucogel 1000) Hyaluronic acid 0.5 NaCl 1
1 MgSO.sub.4 0.5 Phenylbenzimidazole- 1 2 sulphonic acid Carbomer
(Carbopol 981) 0.1 Xanthan gum 0.3 Cellulose gum (Natrosol Plus 0.1
330 CS) NaOH 45% 0.3 0.1 0.7 EDTA solution 1 1 Water ad ad ad ad ad
ad 100 100 100 100 100 100
* * * * *