U.S. patent application number 12/664732 was filed with the patent office on 2010-07-29 for dms (derma membrane structure) in foam creams.
This patent application is currently assigned to Neubourg Skin Care GmbH & Co. KG. Invention is credited to Thomas Neubourg.
Application Number | 20100189662 12/664732 |
Document ID | / |
Family ID | 38830392 |
Filed Date | 2010-07-29 |
United States Patent
Application |
20100189662 |
Kind Code |
A1 |
Neubourg; Thomas |
July 29, 2010 |
DMS (derma membrane structure) in Foam Creams
Abstract
The invention relates to a foam formulation comprising an
emulsion, comprising an oil phase and a water phase, the oil phase
comprising at least one membrane-forming substance forming a
lamellar membrane in the foam formulation.
Inventors: |
Neubourg; Thomas; (Werne,
DE) |
Correspondence
Address: |
STERNE, KESSLER, GOLDSTEIN & FOX P.L.L.C.
1100 NEW YORK AVENUE, N.W.
WASHINGTON
DC
20005
US
|
Assignee: |
Neubourg Skin Care GmbH & Co.
KG
Greven
DE
|
Family ID: |
38830392 |
Appl. No.: |
12/664732 |
Filed: |
June 19, 2008 |
PCT Filed: |
June 19, 2008 |
PCT NO: |
PCT/EP2008/057791 |
371 Date: |
December 15, 2009 |
Current U.S.
Class: |
424/47 ;
510/130 |
Current CPC
Class: |
A61K 8/0295 20130101;
A61Q 19/007 20130101; A61K 2800/33 20130101; A61P 17/00 20180101;
A61Q 19/005 20130101; A61K 8/046 20130101; A61Q 17/04 20130101;
A61Q 19/10 20130101; A61K 8/553 20130101; A61K 8/36 20130101; A61K
8/375 20130101 |
Class at
Publication: |
424/47 ;
510/130 |
International
Class: |
A61K 9/12 20060101
A61K009/12; A61K 8/06 20060101 A61K008/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 19, 2007 |
EP |
071105571.2 |
Claims
1. A foam formulation comprising an emulsion which comprises an oil
phase and a water phase, wherein the oil phase comprises at least
one membrane-forming substance forming a lamellar membrane in the
foam formulation.
2. The foam formulation according to claim 1, wherein the emulsion
is an oil-in-water type emulsion.
3. The foam formulation according to claim 1, wherein the at least
one membrane-forming substance comprises a lipid.
4. The foam formulation according to claim 3, wherein said lipid is
a triglyceride that comprises caprylic acid/caprinic acid
triglyceride.
5. The foam formulation according to claim 3, wherein the lipid
comprises a phospholipid.
6. The foam formulation according to claim 5, wherein said
phospholipid is lecithin or lecithin that comprises hydrated
lecithin.
7. The foam formulation according to claim 1, wherein the emulsion
further comprises at least one thickening agent which is preferably
selected from the group consisting of hydroxypropylmethyl
cellulose, xanthan gum and mixtures thereof.
8. The foam formulation according to claim 1, wherein the emulsion
further comprises a stabilizer.
9. The foam formulation according to claim 8, wherein the
stabilizer comprises pentylene glycol.
10. The foam formulation according to claim 1, wherein the emulsion
further comprises shea butter, glycerol, squalan, ceramide,
preferably ceramide 3 or mixtures thereof.
11. The foam formulation according to claim 1, wherein the emulsion
further comprises an oil or oils lubricating substance.
12. The foam formulation according to claim 1, wherein the emulsion
further comprises at least one active agent.
13. The foam formulation according to claim 12, wherein the active
agent is selected from the group consisting of hydroviton,
pyrrolidone carbonic acid and salts thereof, lactic acid and salts
thereof, glycerol, sorbitol, propylene glycol, urea, collagen,
elastin, silk protein, hyaluronic acid, pentavitin, ceramides,
panthenol, niacin, .alpha.-tocopherol and esters thereof, vitamin
A, vitamin C, galates, polyphenols, panthenol, bisabolol,
phytosteroles, glycocorticoides, antibiotics, analgetics,
antiphlogistics, antirheumatics, antiallergics, antiparasitatics,
antipruriginosics, antipsoriatics, retinoids, local anaesthetics,
therapeutic agents for the veins, ceratolytics, hyperemisic
compounds, coronary therapeutics (nitrates/nitro-compounds), virus
statics, cytostatics, hormones, agents promoting wound healing,
growth factors, enzyme preparations, insecticides and plant
material such as e.g. plant extracts of algae, aloe, arnica,
barber's rash, comfrey, birch, stinging nettle, calendula, oak,
ivy, witch hazel, henna, hops, camomile, ruscus, peppermint,
marigold, rosemary, sage, green tea, tea tree, horsetail, thyme
walnut and mixtures thereof.
14. The foam formulation according to claim 1, wherein the emulsion
is a substantially emulsifier-free emulsion.
15. The foam formulation according to claim 1, wherein the emulsion
is free of emulsifier.
16. The foam formulation according to claim 3, wherein the lipid
comprises bioidentical fats.
17. The foam formulation according to claim 1, wherein the
formulation is a foam cream.
18. The foam formulation according to claim 1, wherein the emulsion
comprises at least one phospholipid and at least one liquid wax
ester.
19. The foam formulation according to claim 18, wherein the
phospholipid comprises lecithin, or a triglyceride.
20. The foam formulation according to claim 1, wherein the
membrane-forming substance is not soluble in water.
21. The foam formulation according to claim 1, wherein the
membrane-forming substance has a HLB value of more than 8.
22. The foam formulation according to claim 1, wherein said
formulation is a skin care agent.
23. The foam formulation according to claim 1, wherein said
formulation is a skin cleaning agent.
24. The formulation according to claim 1, wherein said formulation
is a sunscreen.
25. A method of making a composition that comprises a cosmetic
agent, medical agent or pharmaceutical, wherein said method
comprises the use of a formulation according to claim 1 for the for
the manufacture of said composition.
26. A method for producing a foam formulation comprising the
following steps: a) Producing an emulsion, and b) Filling the
emulsion and propellant into a pressurized container, or filling
the emulsion into a container other than a pressurized container
that upon dispensing of the emulsion generates a foam.
27. The method according to claim 26 wherein said foam formulation
is the formulation according to claim 1.
28. The method according to claim 27, wherein producing the
emulsion comprises the steps: (1) Providing an oil phase optionally
comprising at least one membrane-forming substance that forms a
lamellar membrane in the formulation, (2) Providing a water phase,
(3) Adding and homogenizing both phases, (4) Optionally adding at
least one or at least one further membrane-forming substance, (5)
Optionally homogenizing, in order to obtain an emulsion, wherein in
at least one of the steps (1) or (4) at least one membrane-forming
substance is comprised that forms a lamellar membrane in the
formulation.
29. The method according to claim 28, wherein the oil phase and the
water phase are homogenized at a temperature between about 40 up to
about 90.degree. C.
30. The method according to claim 28, wherein the emulsion
comprises a thickening agent, further comprising the steps: (6)
Providing an aqueous solution of thickening agent, (7) Mixing the
solution of thickening agent with the emulsion.
31. The method according to claim 28, wherein the foam formulation
contains 10 weight percent propellant.
32. The method according to claim 28, wherein homogenizing is
carried out under high energy input.
33. The method according to claim 28, wherein homogenizing is
carried out at a pressure of about 50.000 to about 250.000
kilopascal.
Description
TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to cosmetic and dermatologic
foam formulations, particularly foam creams, based on emulsions of
especially the oil-in-water type, wherein the oil phase comprises
at least one membrane-forming substance forming a lamellar membrane
in the foam formulation.
BACKGROUND OF THE INVENTION
1. Emulsions
[0002] The term "emulsion" generally relates to heterogeneous
systems consisting of two liquids that are not miscible or are only
miscible to a limited extent which are typically designated as
phases. In an emulsion, one of both liquids is dispersed in the
other liquid in the form of fine droplets.
[0003] In case that the two liquids are water and oil and the oil
droplets are finely dispersed in water, the emulsion 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 case of a
water-in-oil emulsion (W/O emulsion, e.g. butter), the opposite
principle applies wherein the basic character is here defined by
the oil.
[0004] In order to obtain a durable dispersion of a liquid in
another liquid, emulsions in a conventional sense require the
addition of a surface active agent (emulsifier). Emulsifiers have
an amphiphilic molecular structure consisting of a polar
(hydrophilic) and a non-polar (lipophilic) part of the molecule
which are separated from each other in space. In simple emulsions,
finely dispersed droplets enclosed by an emulsifier shell of the
one phase are present in the second phase (water droplets in W/O or
lipid vesicles in O/W emulsions). Emulsifiers reduce the surface
tension between the phases because they are arranged in the
boundary surface between the two liquids. They form surface films
at the boundary of the oil/water phases which countervails an
irreversible joining of the droplets. For stabilizing emulsions
mixtures of emulsifiers are often used.
[0005] Conventional emulsifiers can be classified depending on
their hydrophilic part of the molecule into ionic (anionic,
cationic and amphoteric) and non-ionic ones: [0006] The best known
example of an anionic emulsifier is believed to be soap which is
the conventional name for the water-soluble sodium or potassium
salts of saturated and non-saturated higher fatty acids. [0007]
Important members of cationic emulsifiers are the quaternary
ammonium compounds. [0008] The hydrophilic part of the molecule of
non-ionic emulsifiers often consists of glycerol, polyglycerol,
sorbitanes, carbohydrates or polyoxyethylene glycols, respectively,
and is most often connected to the lipophilic part of the molecule
by means of ester and ether bonds. The latter consists typically of
fatty alcohols, fatty acids or iso-fatty acids.
[0009] The term "emulsifier" or "conventional emulsifier"
respectively, is known in the art. Conventional emulsifiers are
described, e.g., in the publications: Pflegekosmetik, 4th edition,
Wissenschaftliche Verlagsgesellschaft mbH Stuttgart, pages 151 to
159 and Fiedler Lexikon der Hilfsstoffe, 5th edition, Editio Cantor
Verlag, Aulendorf, pages 97 to 121.
[0010] By variation of the structure and the size of the polar and
the non-polar part of the molecule, lipophilicity and
hydrophilicity of emulsifiers can be modified to a large
extent.
[0011] The correct choice of emulsifiers is decisive for the
stability of an emulsion. In this respect, the characteristics of
all compounds contained in the system need to be considered. For
example, in case of skin care emulsions, polar oil components such
as e.g. UV filters may lead to instabilities. Apart from
emulsifiers, other stabilizers are, therefore, additionally used,
which, e.g., increase the viscosity of the emulsion and/or act as
protective colloid.
[0012] Emulsions represent an important type of product in the
field of cosmetic and/or dermatologic preparations which is used in
different application fields. Therefore, a variety of
products--such as lotions and creams--are available for skin care,
especially for relubricating dry skin. The aim of skin care is to
compensate for the loss of lipid and water caused by daily washing.
In addition, such skin care products should protect from
environmental stress--in particular from sun and wind, and should
delay skin ageing.
[0013] Cosmetic emulsions are also used as deodorants. Such
formulations are used for eliminating the adore of the body that is
formed when fresh sweat that as such is free of odour is decomposed
by microorganisms.
[0014] Emulsions in the form of cleaning emulsions are also used
for cleaning of the skin and skin adnexa. They are most often used
for the cleaning of the face and especially for removing decorative
cosmetic. Such cleaning emulsions have the advantage--in contrast
to other cleaning preparations such as soap--to be especially mild
on skin since they may contain in the lipophilic phase nurturing
oils and/or non-polar active agents--such as, e.g., vitamin E.
[0015] Since decades, conventional emulsifiers form the basis for
the development of skin care preparations. Emulsifiers were used as
adjuvants for the manufacture and especially for stabilizing
emulsions. Recently there were references that the use of
emulsifiers in skin care preparations may lead to problems e.g. in
case of sensitive skin since emulsifiers typically disturb the
integrity of the natural skin barrier and, thus, cleaning of the
skin may lead to a loss of natural barrier compounds of the skin.
The loss of natural barrier compounds may lead to an increased
roughness, dry skin, cracking and wear eczema.
[0016] Furthermore, the use of emulsifiers normally results in the
conversion of lamellar structures of the lipid barrier into
vesicular structures such as e.g. micelles or mixed micelles. These
vesicles "destroy" at least a part of the barrier layer of the
skin, and, therefore, locally increase the permeability of the
barrier layer membrane. Due to this opening of the barrier layer of
the skin, the loss of water across the skin (TEWL) is at least
temporarily increased and simultaneously the capacity of the skin
to bind moisture is decreased. Continuous application of skin care
preparations having conventional emulsifiers may even lead to
failure of the skin to maintain its protecting function.
[0017] Emulsifier-free emulsions are a special form of an emulsion.
These emulsions are free of emulsifiers in a narrower sense, i.e.
free of amphiphilic compounds having a low molecular weight
(molecular weight of <5000) that in suitable concentrations form
micelles and/or other liquid crystalline aggregates. The IUPAC
defines the term "emulsifier" as follows: Emulsifiers (i.e.
conventional emulsifiers) are surface-active substances. They are
preferably arranged in the boundary surface between oil phase and
water phase and, therefore, reduce the surface tension. Even in low
concentration, emulsifiers facilitate the formation of an emulsion.
In addition, these substances may increase the stability of an
emulsion in that they reduce the rate of aggregation and/or
coalescence. According to an interdisciplinary consensus of
pharmacists, dermatologists and other experts of the Society of
Dermatopharmacy
(http://www.dermotopics.de/german/ausgabe.sub.--1.sub.--03_d/emulgatorfre-
i.sub.--1.sub.--2003_d.htm), a formulation may be defined as
"emulsifier-free" when it is stabilized by means of surface active
macromolecules (having a molecular weight of over 5000) instead of
emulsifiers in a narrower sense (conventional emulsifiers).
[0018] For stabilizing pharmaceutical and cosmetic emulsions,
so-called true emulsifiers are predominantly used, i.e.
conventional emulsifiers in the sense of the present description
that according to their structure and their physical-chemical
behaviour belong to the class of tensides. They are characterized
in an amphiphilic structure and the capability for micelle
association. Compounds and mixtures thereof that lead to the
formation of a lamellar membrane in the sense of the present
invention instead of micelle association are, however, not
considered as conventional emulsifiers. Examples for such compounds
are e.g. phospholipids, such as e.g. lecithins, sphingolipids,
ceramides, cholesterol, fatty alcohols, fatty acids as well as
there mono- and/or diesters, as well as sterols, etc., when they
are dispersed under specific conditions as described below. Such
mixtures of compounds may further contain triglycerides (not
hydrophilic and lipophilic), squalene (not hydrophilic and
lipophilic), or squalane (not hydrophilic and lipophilic).
Preferred examples for membrane-forming substances of the present
invention are phospholipids, sphingolipids, ceramides, cholesterol,
fatty alcohols, fatty acids as well as their mono- and/or diesters,
and sterols. These compounds, e.g. phospholipids, are not soluble
in water in contrast to typical emulsifiers especially tensides
having a comparable HLB-value of about 10. Normally, they form no
micelles or hexagonal liquid crystalline phases. Above the phase
transition temperature, they spontaneously form in water
exclusively large multilamellar vesicles (LUV). Below the phase
transition temperature, they can be dispersed in water under high
energy input and form lamellar structures. The above-mentioned
phase transition temperature indicates in this respect the
temperature at which a gel-like phase is converted into a liquid
crystalline phase. Below the phase transition temperature, a gel
phase is present, above the phase transition temperature, a liquid
crystalline phase is present. Phase transition temperatures vary
depending on the composition (saturated/non-saturated; short/long)
and typically lie, for example, in case of phospholipids between
10.degree. C. and 70.degree. C. For a given system, the phase
transition temperature can easily be determined by means of
DSC.
[0019] Membrane-forming substances also typically contain
lipophilic and hydrophilic parts of the molecule. The capacity of a
membrane-forming substance to form lamellar structures as opposed
to micelles depends, however, in particular on the optimal area
and/or (boundary surface carbon/water), the volume V and the
critical chain length l.sub.c (Israelachvili, Jacob N.:
"Intermolecular and Surface Forces: With Applications to Colloidal
and Biological Systems". 2.sup.nd Edition Academic Press, London,
UK, 1992).
[0020] Furthermore, it is in case necessary to select special
production conditions for a system to form lamellar structures.
These conditions are described below regarding the inventive
systems in more detail. Although systems in which micellar
structures can be converted under suitable conditions into lamellar
structures are known in the art, there are, however, also systems
in which no phase transformation into another phase such as e.g. a
micellar, hexagonal phase, etc. is possible. Still other systems
allow under suitable conditions for the formation of a lamellar
phase, however, an alteration of the concentration does not lead to
the formation of other mesophases.
[0021] Thus, lamellar structures form under well-defined conditions
and are not arbitrarily convertible by means of an alteration of
the concentration into other mesophases such as e.g. micellar
structures. In case of water-soluble tensides (emulsifiers),
micelles, hexagonal and lamellar liquid crystalline phases are
formed depending on the tenside concentration. In this case, it is
possible that depending on the concentration mixtures of different
states (hexagonal and lamellar) are present side by side in
equilibrium. By contrast, membrane-forming substances of the
present invention are typically not soluble in water. In case of
these lipids not soluble in water, such as e.g. phospholipids,
liposomal structures are as a rule not present side by side of
lamellar structures but either the one structure is present or the
other.
[0022] An example of emulsifier-free emulsions are Pickering
emulsions. Pickering emulsions are stabilized by means of solids
which the finely divided solid particles stabilize the emulsion so
that conventional emulsifiers may be substantially omitted. In this
respect, the solids accumulate in the oil/water boundary surface in
the form of a layer whereby the joining of the dispersed phases is
prevented. Solid emulsifiers suitable for this purpose are
particulate inorganic or organic solids that are wettable by both
lipophilic as well as hydrophilic liquids. In Pickering emulsions,
titanium dioxide, tin oxide, silicon dioxide, Fe.sub.2O.sub.3,
veegum, bentonit or ethyl cellulose are preferably used as
solids.
[0023] However, such solid emulsifiers may also lead to irritations
or may even cause allergies in case of sensitive skin.
[0024] Cream bases are already used employing a variety of natural
or skin-like ingredients, respectively, promising a better skin
compatibility especially in case of sensitive skin. In this
respect, it has been shown that the use of skin-like ingredients
results in an improved skin care. Thus, in these cream bases
several components of natural skin lipids, such as e.g.
triglycerides are replaced by caprylic acid/caprinic acid
triglycerides (of plant origin), squalene is replaced by squalane
(or plant origin), ceramides are replaced by ceramide 3 (of yeast
origin), cholesterol is replaced by phytosterols (of plant origin)
and phospholipids are replaced by phospholipids (of plant
origin).
[0025] In this concept, typical adjuvants such as fragrances,
colorants, comedogen lipids (e.g. mineral oils), preservatives and
critical emulsifiers are preferably omitted, since these components
potentially are sensitizing and may lead to irritations of the
skin.
[0026] These formulations are preferably prepared without
conventional emulsifiers in order to avoid the above-mentioned
disadvantages of conventional emulsifiers.
[0027] Without wishing to be bound by a specific theory it is
believed that the special action of these specifically composed
membrane lipids is related to the lamellar structure. Omission of
conventional emulsifiers prevents that micelles or vesicles are
formed so that the lamellar structure of the formed membrane is
maintained in the emulsion. This lamellar structure is based on the
(physical) structure and the (chemical) composition of the natural
epidermal skin lipids that are preferably present as lute substance
between the cells (corneocytes) of the stratum corneum.
[0028] Systems based on specifically composed membrane lipids
having a lamellar structure of the membrane are known in the art
under the term "DMS.RTM." (Derma Membrane Structure).
3. Foam Formulations
[0029] A special application form of cosmetic and/or dermatologic
emulsions is the application as foams. Foam formulations have the
advantage that they can easily be distributed on the skin. The
foamy consistency is experienced as comfortable and the products
normally leave a good skin feeling. In particular, the physical
structure of the foam acts positively on the protective action of
the skin. Foams are complicated physical structures that require a
special balance of the components constituting the foam. In
general, foams are obtained by spraying a formulation of an
emulsion or an aqueous tenside (stabilizer) solution. For example,
an emulsion containing propellant is dispensed from a pressurized
container (such systems are also described in literature and patent
literature as aerosol foams). In this case, the pressurized mixture
of emulsion and propellant expands and forms small foam bubbles. In
particular, the dispersed oil phase in which the oil-soluble gas is
dissolved expands. However, foams can also be formed by means of
other systems such as, for example, pump sprays.
[0030] Upon application, balanced foam formulations have a stable
polydisperse structure of two or more phases that forms on the skin
a network structure that is comparable to a membrane. Such network
structures have the advantage that they develop a protective
action, for example against contact with water, however, allow for
the unhindered gas exchange with the environment. In such foams,
there is practically no obstacle for the perspiratio insensibiles
and no corresponding heat build-up. Thus, the positive properties
of a protective and nurturing action is combined with an unchanged
perspiration.
[0031] Foam formulations known so far contain conventional
tenside/emulsifiers that serve for the stabilization of the
emulsion and for the resulting foam stability.
[0032] Conventional emulsifiers or tensides, respectively, are,
however, repeatedly identified as causing irritations in the use of
skin care products, such as e.g. a dysfunction of the skin barrier
or Mallorca acne.
[0033] Thus, there is a need of individual skin care compositions
that are better adapted to the needs of the skin than conventional
emulsion systems on the basis of emulsifiers and, thus, provide a
better skin protection and a better skin care.
[0034] The use of cream bases having a lamellar structure based in
its composition on the membrane-forming epidermal lipids in foam
formulations so far has not been described.
[0035] It is the object of the present invention to provide
improved foam formulations, particularly improved foam creams,
avoiding the above-mentioned disadvantages of formulations
according to the state-of-the-art.
SUMMARY OF THE INVENTION
[0036] The applicant has surprisingly found that emulsions
comprising an oil phase and a water phase wherein the oil phase
comprises at least one membrane-forming substance forming a
lamellar membrane in the foam formulation are suitable as basis for
foam formulations. In a preferred embodiment, the foam formulations
are substantially free of emulsifier, i.e. they substantially
contain no conventional emulsifiers wherein the substance or the
mixture of substances that leads to the formation of a lamellar
membrane is not considered a conventional emulsifier. For example,
in the technical field it is, for example, acknowledged to
characterize the commercial product Physiogel.RTM. cream containing
DMS.RTM. concentrate as "emulsifier-free".
[0037] Membrane-forming substances and mixtures of substances
according to the present invention are typically non-soluble in
water, while conventional emulsifiers, especially tensides having a
comparable HLB-value of about 10 are as a rule soluble in water.
Furthermore, the membrane-forming substances not soluble in water
according to the present invention are not capable of spontaneously
emulsifying oils, while conventional emulsifiers especially those
having a high HLB-value are capable to spontaneously emulsify oils.
Conventional emulsifiers having a low HLB-value are not capable to
form lamellar structures or liposomes alone in contrast to
membrane-forming substances according to the present invention,
e.g. phospholipids. A special feature of membrane-forming
substances according to the present invention in contrast to
conventional emulsifiers is that, for example, phospholipids have a
HLB of 10, however, are not soluble in water.
[0038] Preferably the membrane-forming substances of the invention
have a HLB-value of more than 8, more preferably of 9 to 11, and
most preferably of 9.5 to 10.5.
[0039] According to the present invention the positive
characteristics of foam formulations are combined with those of
emulsions in which the oil phase comprises at least one
membrane-forming substance that forms a lamellar membrane in the
foam formulation. Thus, especially foam formulations can be
prepared combining the positive properties of the foam, namely the
physical structure and the convenient application, with a good skin
compatibility. This property allows the use of foam formulations
for cosmetic and dermatologic formulations to be employed in case
of sensitive types of skin. Thus, skin compatibility and
convenience of application is combined advantageously with each
other. The lamellar structure of the at least one membrane-forming
substance that is important for the skin compatibility has not been
considered in foam formulations of the state-of-the-art.
[0040] Nevertheless, it is not obligatory that such emulsions lead
to stable foam products upon foaming. Foams are obtained, as
already mentioned, e.g. by incorporating propellants into O/W
emulsion systems. In case that the propellant dissolved in the
dispersed oil phase evaporates upon foaming, a foam is foamed
(dispersion of gas in liquid). Foaming or expanding, respectively,
of the propellant dissolved in the dispersed oil phase leads to a
dilatation of the dispersed oil phase. It now has been surprisingly
found that upon foaming of the inventive foam formulations breaking
of the preparation does not occur and a suitable foam is formed.
The formed foam is stable enough in order to be, e.g., applied to
the skin.
[0041] The invention relates to foam formulations comprising an oil
phase and a water phase, wherein the oil phase comprises at least
one membrane-forming substance that forms a lamellar membrane in
the foam formulation.
[0042] Preferably, the invention relates to foam formulations on
the basis of natural or skin-like ingredients, respectively,
providing for a better skin compatibility.
[0043] Furthermore, the invention relates to the use of foam
formulations based on emulsions as carriers for active agents, as
skin care agent, as skin cleaning agent or as sunscreen. The foam
formulation, therefore, can be employed as cosmetic, medical
product or pharmaceutical composition.
[0044] Moreover, the invention comprises a method of manufacture of
foam formulations based on emulsions in which the oil phase
comprises a membrane-forming substance that forms a lamellar
membrane in the foam formulation. The method comprises the steps:
[0045] a) Producing an emulsion preferably of the oil-in-water
type, [0046] b) Filling the emulsion and propellant into a
pressurized container, or [0047] c) Filling the emulsion into a
container other than a pressurized container that upon dispensing
of the emulsion generates a foam.
DESCRIPTION OF THE DRAWINGS
[0048] FIGS. 1-3 show polarization microscopic photographs of the
foam formulation of example 3.
[0049] FIG. 1 shows lamellar membrane-forming structures that can
be recognized by means of the so-called Maltese crosses (especially
in the upper left image area).
[0050] In addition, in FIG. 2, the gas phase of the foam
formulation can be recognized in the form of gas bubbles. Maltese
crosses can be shown especially in the boundary surface to the gas
phase.
[0051] Moreover, in FIG. 3, Maltese crosses can be recognized in
the boundary surface to the gas bubbles of the foam.
DETAILED DESCRIPTION OF THE INVENTION
[0052] According to the present invention, foam formulations are
formulations, especially emulsions, that are evidently adapted for
the formation of a foam. In particular, the formulations may be
either filled together with a propellant into a pressurized
container or may be filled without propellant into a container
other than a pressurized container that allows for the formation of
a foam upon dispensing of the formulation/emulsion. For example,
pump spray containers may be used.
[0053] In a preferred embodiment, the foam formulation is a foam
cream.
[0054] According to the present invention, essentially
emulsifier-free emulsions are such emulsions that do not contain
more than 1.5 weight percent of conventional emulsifiers,
preferably not more than 1.0%, more preferably not more than 0.5%.
According to the invention, emulsifier-free emulsions are such
emulsions that do not contain conventional emulsifiers.
[0055] According to the present invention, a membrane-forming
substance forming a lamellar membrane is a substance that
preferably has simultaneously a hydrophilic as well as a
hydrophobic part of the molecule. Preferred are substances such as
e.g. phospholipids, such as lecithins, sphingolipids, ceramides,
cholesterol, fatty alcohols, fatty acids as well as mono- and/or
diesters thereof, as well as sterols, etc. Triglycerides (not
hydrophilic and lipophilic), squalene (not hydrophilic and
lipophilic), squalane (not hydrophilic and lipophilic), may also be
contained in mixtures of compounds comprising the membrane-forming
substance.
[0056] Preferred membrane-forming substances are phospholipids,
sphingolipids, ceramides, cholesterol, fatty alcohols, fatty acids
as well as their mono- and/or diesters, and sterols. Such
substances or corresponding mixtures of substances can be dispersed
in a suitable way with an aqueous phase under formation of lamellar
membranes. This can be achieved, for example, by dispersing under
high energy input (e.g. high pressure homogenization, ultrasound).
In case of high pressure homogenization, pressures in the range of
50.000-250.000 kilopascal (500-2500 bar) are employed in this
respect, more preferably of 100.000-150.000 kilopascal (1000-1500
bar). In other cases, a high energy input for forming lamellar
membrane structures is not compulsory necessary (for example often
in case of using non-hydrogenated lecithins having a low phase
transition temperature in connection with suitable lipids, such as
e.g. isopropyl myristate). The use of particular concentrates
forming a lamellar phase is also possible.
[0057] The presence of lamellar structures in the dispersion can
easily be determined by a person skilled in the art by means of
methods known in the art. Suitable methods of measuring are, for
example, described in Claus-Dieter Herzfeld et al. (editor),
Grundlagen der Arzneiformlehre, Galenik 2, Springer Verlag, 1999.
In this respect, the method of polarization microscopy is
especially worth noticing. In this method, two polarization films
in the so-called cross position in which the oscillation planes of
the generated polarized light are perpendicular to each other are
placed above and below the object to be analyzed. The oscillation
plane of the irradiated light is changed by the sample so that a
fraction of the light can pass through the second polarization
film. The presence of lamellar phases can be recognized here
typically by means of so-called Maltese crosses.
[0058] According to the present invention, a lamellar membrane is
arranged such that it has a layered structure such that the upper
layer of the substance is respectively directed to a lower layer of
the substance. The direction of the individual substance layers
occurs independently of the used solvent such that e.g. the
hydrophilic parts of the substance are directed outwards and the
hydrophobic moieties are directed inwards to each other, or vice
versa.
[0059] In case that two layers of the substance are directed in the
above-described sense, the resulting structure is designated as a
single membrane, while in case of arranging two further layers,
this lamellar structure is designated as a double membrane.
According to the present principle, still further layers may be
associated to the (double) membrane already present resulting in a
multiple membrane structure. According to the present invention,
the membrane may be present as a single membrane, as a double
membrane or also as a multiple membrane.
[0060] A "wash-out" effect is understood as a decreasing of the
moisture of the skin after completing an application of the skin
care composition below the initial value.
[0061] According to the present invention, bioidentical fats are
fats of plant origin that occur in the body.
Oil Phase
[0062] Suitable components that may form the oil phase may be
selected from polar and unpolar lipids or mixtures thereof.
[0063] The oil phase of the inventive formulations is
advantageously selected from the group of phospholipids, such as
lecithins, (mono-, di-, tri-) glycerides (especially triglycerides,
such as e.g. fatty acid triglycerides), sphingolipids, from the
group of propylene glycol or butylene glycol fatty acid esters,
from the group of natural waxes of animal or plant origin, from the
group of ester oils, from the group of dialkyl ethers and dialkyl
carbonates, from the group of branched and non-branched
hydrocarbons and waxes as well as from the group of cyclic and
linear silicon oils.
[0064] Foam formulations according to the present invention allow
for an improved skin care action of the formulation due to the
lamellar membrane structure and the resulting structural similarity
to the structure of intercellular lamellar lipid structure of
epidermal lipids, especially the stratum corneum. Due to the
analogous structure of the lamellar structure of the skin,
integration of the membrane into the skin is facilitated. The
integration leads also to an improvement, especially a
stabilization and recovery of the skin barrier. An intact skin
barrier protects the skin from too high a moisture loss. An
improvement of the skin barrier can also result in an improved
smoothing of the skin and may decrease the "wash-out" effect,
whereby advantageously an improved long-term effect is obtained in
comparison to conventional foam formulations.
[0065] Preferred foam formulations of the present invention employ
"skin-like" components, in order to obtain similarity of the
lamellar membrane present in the foam formulation with the skin. In
this respect, especially preferred embodiments replace, e.g., the
natural glycerides present in the sub-corneas layer (the skin
predominantly contains a mixture of di- and triglycerides) by,
e.g., triglycerides (of plant origin), squalene by, e.g. squalane,
which is less sensitive to oxidation, ceramides by ceramide 3 (from
yeast), cholesterol by phytosteroles (of plant origin) and
phospholipids by phospholipids (of plant origin).
[0066] In a preferred foam formulation of the invention, the
membrane-forming substance comprises a lipid, more preferably a
triglyceride and/or phospholipid. In an especially preferred foam
formulation of the invention, the triglyceride is caprylic
acid/caprinic acid triglyceride and/or the phospholipid is
hydrogenated lecithin.
[0067] In a further preferred foam formulation of the present
invention, the formulation may further comprise lecithin,
preferably hydrogenated lecithin.
[0068] The preferred inventive foam formulations may further
contain further components, such as e.g. stabilizers such as e.g.
alcohols or glycols. Preferred are glycols, in particular propylene
glycol, caprylyl glycol or mixtures thereof.
[0069] In preferred foam formulations of the invention, further
components may be comprised such as e.g. butyrospermum parkii (shea
butter), squalane, glycerides, ceramides, preferably ceramide 3, or
mixtures thereof.
[0070] A preferred foam formulation of the invention comprises a
substantially emulsifier-free emulsion. An especially preferred
foam formulation of the invention is free of emulsifier. In a
particularly preferred embodiment, the foam formulation is free
from water-soluble conventional emulsifiers having a HLB-value of
about 10. In a preferred embodiment, the formulation is especially
free from the following compounds:
[0071] Carboxylates, such as e.g. sodium stearate, aluminium
stearate;
sulphates, such as e.g. Na-dodecyl sulphate, Na-cetyl stearyl
sulphate, Na-laurylether sulphate;
Sulphonate: Na-dioctylsulphosuccinate;
[0072] Quaternary ammonium compounds, such as e.g. cetyl trimethyl
ammonium bromide, benzalconium bromide; Pyridinium compounds, such
as e.g. cetyl pyridinium chloride; Betains, such as e.g. betain
monohydrate; Macrogol fatty acid esters, such as e.g.
macrogol-30-stearat; Glycerol fatty acid esters, such as e.g.
glycerol monostearate, glycerol monooleat, glycerol
monoisostearate, partial glycerides, polyoxyethylene sorbitan fatty
esters of medium chain length, such as e.g. Tween.RTM.,
polyoxyethylene-(20)-sorbitan monostearat; Sorbitan fatty acid
esters, such as e.g. sorbitan laurat, sorbitan monooleat, sorbitan
monopalmitate, sorbitan monostearate, sorbitan tristearate,
sorbitan sesquioleat; Sucrose fatty acid esters, such as e.g.
sucrose monostearate, sucrose distearate, sucrose cocoate; Macrogol
fatty alcohol ethers, such as e.g. Cetomacrogol 1000, macrogol
cetostearylether, macrogol oleylether, Lauromacrogol 400; Stearin
alcohols, such as e.g. cholesterol, lanolin, acetylated lanolin,
hydrogenated lanolin, lanolin alcohols; macrogol glycerol fatty
acid esters, such as e.g. macrogol-1000-glycerol-monooleat,
Macrogol-1000-glycerol-monostearat, macrogol-1500-glycerol,
triricinoleat, macrogol-300-glycerol-(hydroxyl stearat),
macrogol-5-glycerol-stearat, macrogol glycerol hydroxystearat;
Polyglyercol fatty acid ester, such as e.g. triglycerol
diisostearat.
[0073] In the present invention, the oil phase comprising a
suitable substance or such a mixture of substances for forming the
lamellar membrane is dispersed with a water phase under conditions
that result in the formation of a lamellar phase. If necessary,
this is done, for example, by dispersing under high energy input,
such as e.g. by ultrasound or by means of high pressure
homogenization, wherein pressures of about 50.000 to about 250.000
kilopascal (about 500 to about 2500 bar), preferably about 100.000
to about 150.000 kilopascal (about 1000 to about 1500 bar) are
used. In other cases, especially when using non-hydrogenated
lecithin having a low phase transition temperature as the
membrane-forming substance, simple dispersing is often already
sufficient without the additional need of high energy input. The
presence of a lamellar phase can, as mentioned above, easily be
determined by a person skilled in the art using methods known in
the art such as e.g. polarization microscopy.
[0074] In an especially preferred embodiment, the membrane-forming
substance comprises a phospholipid, such as e.g. lecithin or
hydrogenated lecithin, and additionally a lipid. More preferably,
the phospholipid is a mixture of lecithin and hydrogenated
lecithin. In an especially preferred embodiment, the weight ratio
of lecithin to hydrogenated lecithin is about 10:1 to about 1:10,
more preferably about 5:1 to about 1:5 and still more preferably
the ratio of lecithin to hydrogenated lecithin is about 1:1. The
lipid present in addition to phospholipid comprises in a preferred
embodiment a liquid wax ester, such as e.g. isopropyl myristate,
-palmitat, stearat or the like. Furthermore, further optional
lipids, such as e.g. peanut oil or triglycerides of medium chain
length (preferably C.sub.8-C.sub.12 triglycerides), may be present
in addition to wax ester. The weight ratio of total phospholipid
(e.g. lecithin+hydrogenated lecithin) to total lipid (e.g. wax
ester+optional triglycerides) is in this embodiment preferably
about 1:5 to about 1:1, preferably about 1:2.
[0075] The mixture of phospholipid and lipid is, for example,
dispersed as a melt with water under high energy input. The high
energy input can be effected by means of ultrasound or by means of
high pressure homogenization, wherein pressures of 50.000 to
250.000 kilopascal (500 to 2500 bar) are employed, preferably
100.000 to 150.000 kilopascal (1000 to 1500 bar). In the water
phase, further additives may optionally be present as described in
the present specification, such as e.g. glycerol or thickening
agent (e.g. xanthan gum and/or hydroxypropylmethyl cellulose
(hypromellose)).
[0076] Further optional ingredients are described below in
connection with DMS.RTM. compositions. In particular, the obtained
formulation may be substantially emulsifier-free, preferably free
of emulsifier, i.e. in the formulation, substantially no or no,
respectively, conventional emulsifier is present, wherein the
membrane-forming substance or the membrane-forming mixture of
substances is not considered a conventional emulsifier. Upon
dispersing this mixture in the described manner, a dispersion is
obtained that is suitable for forming a foam formulation (e.g. by
using propellants or a pump spray) and further for forming a
lamellar membrane.
[0077] Further cream bases based on the above-described "skin-like"
components are also known in the art as DMS.RTM. cream bases.
[0078] The DMS.RTM. base compositions can have the following
components: caprylic acid/caprinic acid triglyceride, shea butter,
squalane, ceramide 3, hydrogenated lecithin, palm glycerides,
persea gratissima, palm oil (elaesis guineensis).
[0079] As stabilizers in the DMS.RTM. compositions may be used e.g.
alcohols or glycols such as e.g. pentylene glyclol, caprylyl glycol
or mixtures thereof.
[0080] A commercially obtainable DMS.RTM. base comprises caprylic
acid/caprinic acid triglyceride, shea butter, squalane, ceramide 3,
hydrogenated lecithin as well as pentylene glycol.
[0081] A further commercially obtainable DMS.RTM. base comprises
caprylic acid/caprinic acid triglyceride, shea butter, squalane,
ceramide 3, hydrogenated lecithin as well as alcohol.
[0082] A further commercially available DMS.RTM. base comprises
caprylic acid/caprinic acid triglyceride, shea butter, squalane,
ceramide 3, hydrogenated lecithin, persea gratissima as well as
caprylyl glycol.
[0083] A further commercially available DMS.RTM. base comprises
caprylic acid/caprinic acid triglyceride, shea butter, squalane,
ceramide 3, hydrogenated lecithin, palm glycerides, elaesis
guineensis as well as pentylene glycol.
[0084] A preferred DMS.RTM. base comprises caprylic acid/caprinic
acid triglyceride, butyrospermum parkii, squalane, ceramide 3,
hydrogenated lecithin, as well as pentylene glycol.
[0085] An especially preferred caprylic acid/caprinic acid
triglyceride is obtainable under the designation Miglyol 812 of the
company Sasol and mixtures thereof with further oil and wax
components.
[0086] In addition, especially preferred is the caprylic
acid/caprinic acid triglyceride obtainable under the designation
Miglyol 812 of the company Sasol/Myritol 312 of the company
Cognis.
[0087] The inventive emulsions preferably contain from about 5 to
50 weight percent oil phase, especially preferably 10 to 35 weight
percent and more preferably 15 to 35 weight percent oil phase. The
data respectively refers to the total weight of the emulsion
without propellant.
[0088] These cream compositions are in particular used in case of
irritated, dry up to very dry, sensitive up to very sensitive,
allergic and eczemic skin.
[0089] In addition, the oil phase preferably may contain further
components, such as e.g. fatty acids, in particular stearinic acid,
or oils, such as e.g. Cetiol V.
[0090] In the DMS concentrates and the inventive formulations,
further conventional adjuvants (not bioidentical) such as
fragrances, colorants, comedogene lipids (e.g. mineral oils) and
physiologic emulsifiers are preferably omitted, since these
components are potentially sensitizing and may lead to irritations
of the skin.
Aqueous Phase:
[0091] The aqueous phase can contain cosmetic adjuvants, e.g. lower
alcohols (e.g. ethanol, isopropanol), lower dioles or polyoles as
well as ethers thereof (e.g. propylene glycol, glycerole, butylene
glycol, hexylene glycol and ethylene glycol), foam stabilizers and
thickening agents.
[0092] Suitable thickening agents are polymeric thickening agents
that are partly soluble in water or are at least dispersible in
water and form in aqueous systems gels or viscous solutions. They
increase the viscosity of the water in that they either bind water
molecules (hydratation) or, on the other hand, include and
encapsulate the water into their intertwined macromolecules wherein
movability of the water is decreased. Suitable polymers are: [0093]
modified natural materials, such as cellulose ether (e.g.
hydroxypropyl cellulose ether, hydroxyethyl cellulose and
hydroxypropylmethyl cellulose ether); [0094] natural compounds,
such as e.g. agar-agar, carrageen, polyoses, starch, dextrins,
gelatine, casein; [0095] synthetic compounds, such as e.g. vinyl
polymers, polyether, polyimines, polyamides and derivates of
polyacrylic acid; and [0096] inorganic compounds, such as e.g.
polysilicic acid and clay minerals.
[0097] Preferably, a cellulose ether is contained as thickering
agent in the formulation of the invention. Hydroxypropylmethyl
cellulose is especially preferred. A hydroxypropylmethyl cellulose
especially preferred according to the invention is Metolose 90S
H100. The general designation in the art for Hydroxypropylmethyl
cellulose is hypromellose.
[0098] A further preferred thickening agent is xanthan gum,
especially Keltrol.RTM. CG xanthan gum.
[0099] Hydroxypropylmethyl cellulose and xanthan gum can be
employed in the inventive formulations also simultaneously.
[0100] The inventive emulsions preferably contain from 0.2 to 3.0
weight percent thickening agent (based on the dry weight of the
thickening agent and the total weight of the emulsion without
propellant). Especially preferred are 0.5 to 2.5 weight percent
thickening agent.
Active Agents:
[0101] The contained active agent may be selected from all active
agents and mixtures thereof that can be applied to the surface of
the skin. The active agent can act cosmetically or
pharmaceutically. Accordingly, cosmetic or dermatologic (to be
employed as medical product or pharmaceutical composition) foam
formulations are obtained. Furthermore, the formulation may be
employed for protecting the skin against environmental influences.
The active agent can be completely of plant origin or can be
synthetic. The group of active agents may overlap with other groups
of ingredients, such as e.g. the oil component, the thickening
agents or the solid emulsifiers. For example, some oil components
also may act as active agents, such as e.g. oils having
polyunsaturated fatty acids or solid emulsifiers, such as e.g.
particulate titanium dioxide that may serve as UV-filter. Depending
on the characteristics, the substances are to be classified into
several groups.
[0102] Active agents of the inventive formulations are
advantageously selected from the group of substances having
moisturizing and barrier strengthening properties, such as e.g.
hydroviton, an emulation of NMF, pyrrolidone carbonic acid and
salts thereof, lactic acid and salts thereof, glycerol, sorbitol,
propylene glycol and urea, substances of the group of proteins and
protein hydrolysates, such as e.g. collagen, elastin as well as
silk protein, substances of the group of glycose aminoglucanes,
such as e.g. hyaluronic acid, of the group of carbohydrates, such
as e.g. pentavitin that corresponds in its composition to the
carbohydrate mixture of the human sub-corneous layer and the group
of lipids and lipid precursors such as for example ceramides.
Further advantageous active agents in the sense of the present
invention may be selected from the group of vitamins, such as e.g.
panthenol, niacin, .alpha.-tocopherol and its esters, vitamin A as
well as vitamin C. Moreover, active agents selected from the group
of antioxidants e.g. galates and polyphenoles may be used. Urea,
hyaluronic acid and pentavitin are preferred substances.
[0103] It is further preferred that substances having skin soothing
and regenerative action are employed as active agents, such as e.g.
panthenol, bisabolol and phytosteroles.
[0104] Advantageous active agents in the sense of the present
invention are also plants and plant extracts. These are e.g. algae,
aloe, arnica, barber's rash, comfrey, birch, nettle, calendula,
oak, ivy, witch hazel, henna, hop, camomile, ruscus, peppermint,
marigold, rosemary, sage, green tea, tea tree, horsetail, thyme and
walnut as well as extracts thereof.
[0105] The inventive formulations may further contain as active
agents antimycotics and antiseptics/disinfectants of synthetic or
natural origin.
[0106] Further active agents are glycocorticoides, antibiotics,
analgetics, antiphlogistics, antirheumatics, antiallergics,
antiparasitics, antipruriginosics, antipsoriatics, retinoids, local
anaesthetics, therapeutic agents for veins, ceratolytics, hyperemic
substances, coronary therapeutic agents (nitrates/nitro-compounds),
virus statics, cytostatics, hormones, agents promoting wound
healing, e.g. growth factors, enzyme preparations and
insecticides.
[0107] Further components of the emulsion:
[0108] The formulations may optionally further contain colouring
agents, pearlescent pigments, fragrances/perfumes, sunscreen filter
substances, preservatives, complex formers, antioxidants and
repellent agents, as well as pH-value regulating agents.
[0109] However, in a preferred embodiment, formulations of the
invention are free from components that may lead to irritations of
the skin, in particular are free from fragrances, perfume,
colorants and conventional emulsifiers.
[0110] The inventive foam formulations may contain apart from the
components already described above further natural fats such as
e.g. shea butter, neutral oils, olive oil, squalane, ceramides and
moisturizing substances as usual in the art.
[0111] The above list of individual components of the emulsion
should be considered such that individual exemplified components
may be classified into several groups because of its different
properties.
Propellants:
[0112] Suitable propellants are e.g. N.sub.2O, propane, butane and
i-butane. The completed foam formulation contains 5 to 15 weight
percent of propellant, preferably about 10 weight percent.
Method of Manufacture
[0113] The foam formulations according to the invention are
prepared by providing an emulsion, preferably of the oil-in-water
type and filling the emulsion and optionally propellant into a
suitable container such as e.g. a pressurized container. As an
alternative to propellant and pressurized container, the emulsion
may also be filled into a different container that is suitable to
dispense the emulsion as a foam even in the absence of propellant.
Such systems are known to a person skilled in the art.
[0114] In particular, the inventive emulsions are prepared by means
of a method comprising the following steps: [0115] (1) Providing an
oil phase optionally comprising at least one membrane-forming
substance forming a lamellar membrane in the formulation, [0116]
(2) Providing an aqueous phase, [0117] (3) Combining and
homogenizing of both phases, for example, by means of ultrasound or
high pressure homogenization, [0118] (4) Optionally adding at least
one or at least one further membrane-forming substance, [0119] (5)
Optionally homogenizing, for example, by means of ultrasound or
high pressure homogenization in order to obtain an emulsion,
wherein in at least one of the steps (1) or (4) at least one
membrane-forming substance is included that forms in the
formulation a lamellar membrane.
[0120] Preferably, the oil phase and the aqueous phase are each
mixed at a temperature in the range of from about 40 to 90.degree.
C. and are homogenized; a temperature range of from about 60 to
about 80.degree. C. is especially preferred, more preferably a
temperature of about 70.degree. C.
[0121] For homogenizing, every means or method known in the art can
be used. Preferably, the phases are homogenized using a high-speed
stirring device. In a preferred embodiment, homogenizing is carried
out by means of high pressure homogenization. In a further
preferred embodiment, homogenizing is carried out by means of
ultrasound.
[0122] In a preferred production method, the oil phase is mixed
into the aqueous phase and is homogenized. If necessary, the
emulsion is cooled down to room temperature under stirring. In an
especially preferred method, a suitable amount of a DMS.RTM.
concentrate is added to this mixture and the concentrate is
incorporated into the present emulsion. The method that is
described in the following can also be carried out with other
lamellar phases instead of DMS.RTM. concentrate.
[0123] The DMS.RTM. concentrate can already be added to the oil
phase before homogenizing with the aqueous phase or can be added to
the mixture of the homogenizing the oil and aqueous phase. It is
preferred that the DMS.RTM. concentrate is added to the mixture
after the first homogenizing step and the mixture is then
homogenized.
[0124] In case the emulsion comprises a thickening agent, the
method advantageously comprises the following further steps: [0125]
(6) Providing an aqueous solution of thickening agent, [0126] (7)
Mixing the solution of thickening agent with the emulsion.
[0127] Preferably, the inventive emulsion is loaded with about 10
weight percent of propellant.
Applications
[0128] The foam formulations of the present invention can be
employed for all cosmetic and dermatologic (as a medical product or
pharmaceutical composition) purposes. For example, the formulations
may be employed as skin care agent or skin cleaning agent.
Furthermore, they may be used as carriers for active agents and may
be employed in the medical dermatologic field. In particular, the
formulations may be employed as sunscreen.
EXAMPLES
Composition of the Foam Formulation
[0129] a) Aqueous Phase
[0130] The aqueous phase is provided by mixing the components.
TABLE-US-00001 Component Amount HPMC (Metolose 90SH100) 1.5 g
Xanthan gum (Keltrol .RTM. CG) 0.5 g Water 78 g
[0131] b) Oil Phase
Example 1
TABLE-US-00002 [0132] Component Example 1 DMS Concentrate 5 g
Miglyol 812 14 g Stearinic acid 1 g Aqueous phase ad 100 g
Example 2
TABLE-US-00003 [0133] Component Example 2 DMS Concentrate 5 g
Miglyol 812 14 g Stearinic acid 1 g Cetiol V 5 g Aqueous phase ad
100 g
[0134] Stearinic acid is dissolved under heating up to about
70.degree. C. in Miglyol 812 (Example 1) or in the mixture of
Miglyol 812 and Cetiol V (Example 2), respectively.
[0135] This oil phase is added into the aqueous phase under
stirring and is homogenized using a high-speed stirring device. The
resulting emulsion is cooled down to room temperature under
stirring and the DMS.RTM. concentrate is incorporated by means of a
high-speed stirring device.
[0136] The used DMS.RTM. concentrate has the following INCI
components:
[0137] Aqua (and) Hydrogenated Lecithin (and) Caprylic/Capric
Triglyceride (and) Pentylene Glycol (and) Butyrospermum Parkii
(and) Glycerin (and) Squalanee (and) Ceramide 3
Manufacture of the Foam Formulation
[0138] 90 g of the emulsion prepared as above are filled into an
aerosol container and are loaded after closing with a valve cap
with 10 g propellant.
Example 3
TABLE-US-00004 [0139] Component Example 3 soya lecithin 3.0 g
hydrogenated soya lecithin 3.0 g triglycerides of medium chain 7.0
g length isopropyl myristate 7.0 g xanthan gum 0.4 g hypromellose
1.2 g glycerol 85% 5.0 g water 73.4 g
Manufacture
[0140] The mixture of soya lecithin and hydrogenated soya lecithin
(e.g. Phospholipon 80H and phospholipon 85 G) is dissolved in a
mixture of triglycerides of medium chain length (e.g. Miglyol 812)
and isopropyl myristate at 60.degree. C. Under high energy input
(e.g. ultrasound or high pressure homogenization), the lipid melt
is dispersed in a mixture of water and glycerol (high pressure
homogenizer: Avestin Emulsiflex-C3; pressure: 1400 bar).
Subsequently, the solution of xanthan gum (e.g. Keltrol CG) and
hypromellose (e.g. Metolose 90SH100) in water is added under
stirring.
Manufacture of the Foam Formulation
[0141] 90 g of the membrane-forming emulsion as prepared above are
filled into an aerosol container and is loaded with 10 g propellant
after closing with a valve cap.
Foam Formation
[0142] A stable cream-like foam having fine bubbles is formed upon
dispensing the foam formulation from the pressurized container by
means of a suitable valve having a foam applicator attached. The
structure of the cream-like foam is maintained for a duration that
is sufficient for uniformly dispersing the foam on the skin.
* * * * *
References