CA2294024A1

CA2294024A1 - Shellac-containing cosmetic product

Info

Publication number: CA2294024A1
Application number: CA002294024A
Authority: CA
Inventors: Karin Golz-Berner; Leonhard Zastrow
Original assignee: Individual
Current assignee: Lancaster Group AG
Priority date: 1997-08-01
Filing date: 1998-07-21
Publication date: 1999-02-11
Also published as: EP1001732A1; CN1261268A; DE59807753D1; AU9430798A; DE19734544B4; PL337814A1; WO1999006011A3; DE19734544A1; JP2002509548A; CN1168438C; EP1001732B1; PL192218B1; WO1999006011A2

Abstract

The invention relates to a cosmetic emulsion or a gel that contains shellac.
In accordance with the invention, a shellac-containing cosmetic product is produced which contains shellac in the aqueous phase. The proportion of pure shellac lies between 0.1 and 20 wt.% in an O/W emulsion; between 0.1 and 15 wt.% in a W/O emulsion; and between 0.1 and 10 wt.% in a hydrogel. Between 1 and 20 wt.% of other cosmetically active components or other supporting materials are contained in the oil phase or the aqueous phase, or in both phases. The invention also relates to a method for producing the cosmetic product. In this method, in order to produce the aqueous shellac solution or dispersion that is to be used, 0.1-3 wt.% of a water-soluble film former and 0.1-1 wt.% of an acid-resistant gel former with a pH of 2-4.2 are added.

Description

SBELI~AC-CONTAINING COSMETIC PRODUCT
The invention relates to a cosmetic emulsion or a gel containing shellac.
It is~known that shellac has been used as a resin component in cosmetic hair sprays, hair setting lotions, shampoos and even l0 nail varnish. Shellac was present as a film-forming agent in alcoholic compositions. Shellac has been largely replaced by a number of modern copolymers that have assumed this role.
Nevertheless, shellac is still being used for certain applica-tions such as hair spray and shampoo, not least of all because it is available as a very pure natural product in good quality.
U. S . Patent No. 5, 614, 200 A describes W/0 emulsions that are used as mascara and contain solids, including resins such as shellac, liquid vehicles such as alcohol and a hardening retarder in addition to other cosmetic additives.
Use of shellac as a parting compound between layers to be set off from one another in a light protectant formed from three or more layers is also known from International Patent WO 96/41630, so that a multilayer structure of the light protectant is formed on the skin, and the skin comes in contact only with the layer containing the inorganic light protectant which is tolerated well by the skin.
The object of this invention is to improve upon the feeling of traditional emulsions and gels on the skin by preventing an oily or sticky feeling while at the same time improving on the water resistance and achieving stabile emulsions and gels.

It has been found that addition of an aqueous shellac dispersion to O/W or W/O emulsions or hydrogels may under certain conditions lead to a cosmetic product (emulsion or gel) having a different type of structure and thus also different properties.
The prerequisite for preparation of such emulsions and gels is the use of pure aqueous shellac solutions or dispersions . Shellac is normally soluble only in solvents such as alcohols, ketones and organic acids. Shellac is insoluble in hydrocarbons, and is to soluble in water only in the form of saponified shellac. It has been found that unsaponified shellac is also up to approximately 30 wt% soluble in water under certain conditions, and dispersions in water containing up to approximately 60 wt% are possible. Such solutions/dispersions consist of shellac in the range of 1 to 60 wt%, preferably l0 to 60 wt%, especially 15-60 wt~;
a water-soluble film-forming agent in the range of 0.1 to 3 wt%;
a gel-forming agent that is stable in the acidic range, in the 2o range of 0.1 to 1 wt%;
an acid to adjust the pH to a value of 2 to 4.2,,preferably 2 to 3.5;
and water up to 100 wt%.
These solutions or dispersions are prepared by placing solid, purified, dewaxed shellac in an aqueous acidic solution of the film-forming substance and the gel-forming substance at a pH of 2 to 4.2, while stirring at a temperature in the range of 5°C to 20°C, and then homogenizing the ingredients of the solution or 3o dispersion together well.
Thus, this invention makes available a cosmetic product contai-ning shellac, comprising a pure shellac content in the aqueous phase, wherein the shellac component is in the range of 0.1 to 20 wt% in an 0/W emulsion, in the range of 0.1 to 15 wt% in a W/0 emulsion, in the range of 0.1 to 10 wt% in a hydrogel, and the oily phase or the aqueous phase or both phases may con-tain additional cosmetic active ingredients or vehicles in the range of 1 to 20 wt%. All amounts here are based on the weight of the total composition.
The new cosmetic product permits an especially smooth distribu-tion on the skin without having an oily effect, produces a very pleasant soft feeling on the skin and is not sticky.
Another object of this invention is the above cosmetic product l0 containing shellac, comprising a pure shellac content in the aqueous phase, wherein the shellac component is in the range of 0.1 to 20 wt% in an O/W emulsion, is in the range of o.l to 15 wt% in a W/O emulsion, is in the range of 0.1 to 10 wt% in a hydrogel, and the oily phase or the aqueous phase or both phases may con-tain additional cosmetic active ingredients or vehicles in the range of 1 to 20 wt%, prepared by a) preparing an emulsion or a hydrogel in the usual way by mixing a primary emulsion phase, containing the cosmetic active ingre dients and additives provided therein, with a secondary emulsion phase, containing the cosmetic active ingredients and additives provided therein;
or mixing a gel-forming substance with water and adding the cosmetic active ingredients and additives provided therein;
and b) preparing a 5 wt% to 60 wt% aqueous shellac solution or dis-persion by mixing pure shellac dry solids having a molecular weight of approximately 1000 to 1010 with water in the presence of a water-soluble film-forming substance and a gel-forming substance that is stable in an acidic pH range at a temperature of 5°C to 20°C and a pH of 2 to 4.2;
and c) heating the emulsion or the gel from step a) to a temperature in the range of 35°C to 45°C while stirring;
and d) adding the shellac solution or dispersion from step b) to the former while stirring at 150 to 1000 rpm for a period of 5 to 60 minutes at 20 °C to 45 °C; and then e) cooling the resulting product to ambient temperature.
The temperature for process step b) is advantageously in the range of 5 °C to 15 °C.
For example, a polyvinylpyrrolidone such as PVPK30° may be used to as the water-soluble film-forming substance. Other possible film-forming substances include chitosan, microcrystalline chitosan, quaternary chitosan, polymers of the acrylic acid series, quaternary cellulose derivatives, hyaluronic acid and the salts thereof, as well as mixtures thereof.
An example of a gel-forming substance that is stable in the acidic range is a modified natural polysaccharide such as guar hydroxypropyltrimonium chloride (Jaguar C14S'). Other possible gel-forming substances include agar, alginates, alginic acid as well as mixtures thereof.
The shellac used here may be a processed product. Shellac is a natural lac resin secreted by the female lac insect Laccifer lacca Kerr. The purified wax-free resin used for cosmetic pur-poses has a molecular weight of approximately 1000, consists of a series of hydroxymono- or dicarboxylic acids in the form of lactones, lactides and intramolecular esters. The main components are aleuritic acid, shellolic acid and jalaric acid (C~SHzo05) with molecular weights of 304, 296 and 280, respectively. Shellac is 3o therefore more like an oligomer of hydroxycarboxylic acids than a polymer. Impurities can be removed by means of a solvent extraction method, e.g., with an alcohol, and after decolorization with activated carbon and evaporating the alcohol, shellac can be converted to a yellowish to faintly yellowish solid.
Such a solid is a starting material for the aqueous solutions or dispersions used with this invention.

The present invention makes possible for the first time the use of shellac in pure form as an aqueous solution or dispersion with a viscosity of >l00 mPa~s (cP) in aqueous cosmetic products in an advantageous manner, in particular in 0/W emulsions.

These shellac solutions/dispersions have a viscosity of approx.
500 mPa~s (cP) at a shellac content of 10 wt%, approx. 1000 mPa~s ( cP ) at 20 wt% and approx. 2500 mPa ~ s ( cP ) at 35 wt% . Shellac solutions or dispersions of approx. 400-500 mPa~s (cP) and higher l0 are preferred. Thus, dispersions of 55-60 wt% shellac have a viscosity of approx. 100,000 mPa~s (cP), have a creamy to pasty consistency and can still be processed well with existing equip-ment. Since the viscosity depends on the shellac concentration in an aqueous dispersion or solution, it is expedient to work with these viscosities in practical implementation of this invention.
In the case of an O/W emulsion, the structure of an emulsion according to this invention is presumably such that the shellac is distributed in the continuous aqueous phase, or in a W/O
emulsion, water droplets axe surrounded by a layer of the natural shellac resin, or in a hydrogel, shellac droplets are present in a random distribution in the gelled aqueous phase.
The shellac content in the emulsion or in the hydrogel is in the range of 0.5 to 20 wt%, preferably in the range of 0.5 to 8 wt%.
In the O/W emulsion, the oil content is in the range of 3 to 20 wt%, preferably 3.5 to 7.7 wt%, and the water content is in the range of 50 to 80 wt%, preferably 50 to 65 wt%.
In the W/O emulsion, the water content is in the range of 40 to 65 wt%, preferably 40 to 55 wt%, and the oil content is in the range of 5 to 20 wt%, preferably 4.5 to 10 wt%. In the hydrogel, the water content is in the range of 40 to 80 wt%, preferably 50 to 80 wt%.
In addition, it is preferable for the concentration of the aque-ous shellac solution or dispersion to be 15 to 50 wt%.

5a The cosmetic product according to this invention may also be a multiple emulsion of the W/O/W type or the O/W/O type.
The shellac content in the finished cosmetic product in an O/W
emulsion is preferably in the range of 5-20 wt%, in a W/O emul-sion it is in the range of 5-15 wt%, and in a hydrogel it is in the range of 3 to 10 wt%.
The cosmetic product containing shellac according to this inven-tion is advantageously in the form of a cream, lotion, sunscreen preparation, lipstick, makeup, mask, lip gloss, spray or gel.
The oily phase or the aqueous phase or both phases may contain additional active cosmetic ingredients and cosmetic vehicles or additives.
Active cosmetic ingredients include, for example, emulsifiers 2o such as 1-decane homopolymer, polyglycerine ester and other known emulsifiers for W/O emulsions, as well as C12-C15 alkyl benzoates, beeswax, steareth, shea butter and other known O/W
emulsifiers.
Other possible additives include isopropyl myristate, isopropyl palmitate, isopropyl stearate, carbomer, cetearyl alcohol, lecithin, copolymers, paraffin oil, cetyl alcohol, propylene glycol, polyglycol, jojoba oil, silicone oil, coconut oil, palm oil, mineral oil, cetyl palmitate, acrylates, C10-C30 alkyl acrylate crosspolymer, magnesium aluminum silicate, hydroxyethyl-cellulose and other substances with which those skilled in the art are familiar and which are adapted to the specific applica-tions such as lipstick, eye makeup, other cosmetics, etc.
As additional active ingredients, the preparation may contain l0 1, 3- and 1, 6-f3-glucan, CM-glucan° , allantoin, Tio2, ZnO, Zro2, Sio2 and additional UVA and UVB blocking substances such as or-ganic sunscreens. For example, benzophenone derivatives, 3-benzy-lidene camphor derivatives, esters of cinnamic acid or salicylic acid, 4-aminobenzoic acid derivatives, such as benzophenone-3, butylmethoxydibenzoylmethane, octyl methoxycinnamate, octyl salicylate and also water-soluble products such as phenylbenzimi-dazolesulfonic acid or benzophenone sulfonic acid derivatives may be used for this purpose. Combinations with WA filters are also possible.
An emulsion according to this invention may also contain powdered substances selected from the group consisting of pigments such as metal oxides (iron oxides, Ti02, ultramarine blue, chromium oxi-de, mica-titanium oxide, mica-iron oxide, mixtures thereof) and also other powdered substances such as Sio2, silica, Zno, kaolin, ~Si02-modified kaolin (according to Wo96/17588), polytetrafluoro ethylene, nylon, talc, mica, polymethyl methacrylate, polyethyle ne, natural organic compounds such as encapsulated or unencapsu lated grain starch and mixtures thereof.
In addition, cosmetically beneficial additives that can also be used include water, monohydric and polyhydric alcohols, such as ethanol, isopropanol, propylene glycol, glycerol, ethylene gly-col, C9-C» alcohols, etc.; methyl, ethyl or butyl ether with ethylene glycol; propylene glycol or diethylene glycol; gel-forming substances; vitamins such as vitamin A, E, B2, B6, BIZ, C;
panthenol, aloe vera, allantoin, bisabolol; coloring agents;
preservatives; protective agents, radical scavengers; enzymes, plant ingredients; natural anti-inflammatory agents; moisturi-zers; antioxidants; pIi regulators; pigments such as soluble melanin; perfume; copper gluconate, etc.
In addition, the emulsion or the gel may contain oxygen-loaded asymmetrical lamellar aggregates according to W094/00109 or dispersed or magnetically hard, single-crystal particles contai-ned in the asymmetrical lamellar aggregates or in liposomes and having a high coercive field strength according to W095/03061.
to Digestion products of yeasts or plant substances produced by a gentle ultrasonic digestion method according to W094/13783 are also very advantageous.
The invention has the following advantages:
1. Incorporating shellac into emulsions or hydrogels leads to an improved feeling on the skin, which has been proven by tests, 2. Adhesion to the skin is improved for decorative cosmetics, i.e., lipstick, tinted daily creames, makeup-cosmetics, powder and all products containing pigments and pigment-like substances such as magnetically hard single-crystal parti-cles of barium or strontium hexaferrite (see W095/03061).
3. Stability in water is increased in sun care products, i.e., sun lotions, sun emulsions, after-sun care lotions, sun gels, etc.
4. In sun care products it acts as an anti-salt water/anti-sand agent, because it does not leave any oily film on the skin.
5. No stickiness on the skin is detected with any products.
6. Homogeneous emulsions are also obtained with large amounts of inorganic pigments such as Ti02 or Zn0 or combinations of Ti02, Zno and Si02, which is advantageous for sun care pro-ducts with a high sunscreen factor in particular.

7. An especially permanent (long-lasting) product is achieved with lipstick and lip gloss with a special gloss that can be described as matt brilliance.
The invention will be explained in greater detail below on the basis of examples. All amounts are based on weight unless ex-plicitly stated otherwise.
Example 1 l0 Preparation of an O/W Emulsion An 0/W emulsion was prepared from the following ingredients.
Phases A and B were prepared separately at 60°C while stirring and were combined at the aforementioned temperature and then cooled to 40°C. Phases C and D were added to the total mixture while stirring.
Phase A
C12-C15 alkyl benzoate 3.5%
Steareth 1.5%
Phase B
water q.s. ad 100 Glycerol 1.5%
Coloring pigments 2.0%
Phase C .
Babassu oil 2.5%
Silicone oil 1.5%
Preservative 0.3%
Phase D
Perfume oil 0'.2% , Example 2 Preparation of an Aqueous Shellac Solution/Dispereion While stirring, the pH was adjusted to 3.3 with citric acid in 100 mL water. Then 1.3 g polyvinylpyrrolidone (PVPK30°) and 0.6 g guar hydroxypropyltrimonium chloride (CTFA name) (Jaguar C14S°) were added while stirring further. To the resulting sol-ution was added 15 g purified, dewaxed, particulate shellac at approximately 13-15'C and at less than 1000 rpm, and the solution was homogenized at 1450 rpm.
The shellac solution prepared in this way had a viscosity of 54o cP~s. Solutions and-dispersions with higher viscosities and concentrations of shellac were prepared in the same way, varying the pH, the amount of shellac used and the amounts of the other components.

Examgle 3 Preparing a W/O Emulsion A W/O emulsion was prepared from the following ingredients.

Phases A and B were prepared separate ly at 85C while stirring and combined at the same temperature and cooled to 40'C while stirring. Then phase C was added to the total mixture while stirring.

Phase A

1-Decane 11.0%

Polyglycerol ester 3.0%

Mineral oil 5.0%

UV filter TiOZ/Zn0/benzophenone-3 3.5%

Si02 (monodisperse) (Merck) .1.0%

Phase B

Distilled water q.s. ad 100 Glycerol 6.0%

Phase C

Preservative 0.2%

Perfume oil 0.1%

Example 4 Preparation of the Gel Phases A through C were prepared and mixed together in succession in this order at room temperature and homogenized.

Phase A

Distilled water q.s. ad 100 Crosspolymer 1.0%

Glycerol 2.0%

Phase B

Triethanolamine 1.0%

Phase C ' Perfume oil 0.2%

Preservative, chamomile extract 2.0%

Vitamin E 0.5%

Vitamin C 0.5%

Vitamin B2 1.0%
Example 5 Tanning Day Cream A shellac solution with a shellac content of 20%, prepared accor 5 ding to Example 2, was added as phase E in the amount of 15.0% to the mixture from Example 1 at 35°C while stirring until the mixture was homogeneous.
Example 6 Sun emulsion to A shellac solution with a shellac content of l0%, prepared accor-ding to Example 2, was added as phase D in the amount of 20.5% of the total composition to the mixture from Example 3 at 35'C while stirring until the mixture was homogeneous.
Example 7 Skin care gel A shellac solution or dispersion with a shellac content of 1%, prepared according to Example 2, was added as a component of phase C in the amount of 20.5% of the total composition to the .mixture from Example 4 at ambient temperature while stirring until the mixture was homogeneous.
Example 8 Lipstick .
Phase A
Wax WM300/46 (CTFA name) 70%
Castor oil 12%
PPG 1-glyceryl oleostearate paraffin 0.5%
Coloring agents 4.5%
Phase B
DMDM hydantoin ~ 0.6%
PPG 518MDI copolymer (CTFA name) 1.0%
Water q.s. ad 100 Phase C
Perfume oil 0.5%
Phase A was melted while stirring at 80'C. Phase A was added to phase B at 80'C while stirring. Then the mixture was cooled to 5o'C, and phase C was added at this temperature while stirring.
Then a shellac dispersion with a shellac content of 50%, prepared according to Example 2, was added in the amount of 5% of the ,CA 02294024 1999-12-10 total composition while stirring until the mixture was homogene-ous, and then the product was solidified.
Experimental Example 1 A product that was designated as " product A" was prepared according to Example 6. A similar product like that in Example 6 was prepared, but no shellac solution was added. This product was designated as "product B."
For the purpose of testing while sunbathing, the two prod ucts were applied to the entire body of ten volunteers who were to already pre-tanned.
Product A gave adequate W protection on all volunteers. The product was applied only once each time over the period of the daily four-hour sunbath, and it had a sufficient water resistance with three interruptions by a l0-minute water bath each time.
Product B was applied at least twice by eight volunteers during the period of the daily four-hour sunbath to achieve the same UV protection. Its stability in water was not adequate.

Claims

1.A cosmetic product containing shellac, comprising a shellac content in the aqueous phase, where the amount of pure shellac in an O/W emulsion is in a range of 0.1 to 20 wt%, in a W/O
emulsion is in a range of 0.1 to 15 wt%, in a hydrogel in the range of 0.1 to 10 wt%; the aqueous phase also contains a water-soluble film-forming substance and a gel-forming substance that is stable in an acid range, and the oily phase or the aqueous phase or both phases contain additional active cosmetic ingredients or vehicles in the range of 1 to 20 wt%, all amounts based on the weight of the total composition.

2. A cosmetic product containing shellac, comprising a shellac content in the aqueous phase, where the amount of pure shellac is in a range of 0.1 to 20 wt% in an O/W emulsion, in a range of 0.1 to 15 wt% in a W/O emulsion, in a range of 0.1 to 10 wt% in a hydrogel, and the oily phase or the aqueous phase or both phases contain additional active cosmetic ingredients or vehicles in the range of 1 to 20 wt%, where all amounts are based on the weight of the total composition, prepared by a) preparing an emulsion or a hydrogel in the usual manner by mixing a primary emulsion phase containing active cosmetic ingredients and additives therein, with a secondary emulsion phase containing active cosmetic ingredients and additives therein, or mixing a gel-forming agent with water and adding the active cosmetic ingredients and additives provided;
and b) preparing a 5 to 60 wt% aqueous shellac solution or dispersion by mixing pure shellac dry solids having a molecular weight of approx. 1000 with water in the presence of a water-soluble film-forming agent in the range of 0.1 to 3 wt% and a gel-forming agent that is stable in the acidic range in a concentration range of 0.1 to 1 wt%
and an acid for adjusting the pH to a value of 2 to 4.2 while stirring at 150 to 1000 rpm for a period of 5 to 60 minutes at 5 °C to 20 °C;
and c) heating the emulsion or the gel from step a) to a temperature in the range of 35 °C to 45 °C while stirring and d) adding the shellac solution or dispersion from step b) while stirring at 150 to 1000 rpm for a period of 5 to 60 minutes at 35 °C to 45 °C;
and then e) cooling the resulting product to ambient temperature.

3. A product according to claim 2, wherein the concentration of the aqueous shellac solution or dispersion amounts to 10 to 60 wt%.

4. A product according to claim 1 or 2, wherein the concentration of the aqueous shellac solution or dispersion amounts to 15 to 60 wt%.

5. A product according to claim 4, wherein the concentration of the aqueous shellac solution or dispersion amounts to 15 to 50 wt%.

6. A product according to claim 1, comprising a multiple emulsion of the W/O/W type or the O/W/O type.

7. A product according to claim 1 or 2, wherein the shellac content in the finished cosmetic product is in the range of 5-20 wt% in an o/W emulsion, in the range of 5-15 wt% in a W/O
emulsion, or in the range of 3-to wt% in a hydrogel.

8. A product according to claim 1 or 2, wherein the shellac content in the emulsion or the hydrogel is in the range of 0.5 to 8 wt%.

9. A product according to one of claims 1 through 8, wherein the viscosity of the shellac solution or dispersion is in the range of 500 to 100,000 mPa~s (cP).

10. A product according to claim 9, wherein the viscosity of the shellac solution or dispersion is in the range of 1000 to 100,000 mPa~s (cP).

11. A product according to claim 9, wherein the viscosity of the shellac solution or dispersion is in the range of 2500 to 100,000 mPa~s (cP).

12. A product according to one of claims 1 through 11, wherein it is in the form of a cream, lotion, sunscreen preparation, lipstick, makeup, mask, lip gloss, spray or gel.

13. A method of producing a cosmetic product containing shellac, comprising the following steps:
a) preparing an emulsion or a hydrogel in the usual manner by mixing a primary emulsion phase containing active cosmetic ingredients and additives therein, with a secondary emulsion phase containing the active cosmetic ingredients and additives therein, or mixing a gel-forming agent with water and adding the active cosmetic ingredients and additives provided;
and b) preparing a 5 to 60 wt% aqueous shellac solution or dispersion by mixing pure shellac dry solids having a molecular weight of approx. 1000 with water in the presence of a water-soluble film-forming agent in the range of 0.1 to 3 wt% and a gel-forming agent that is stable in the acidic range in a concentration range of 0.1 to 1 wt%
and an acid for adjusting the pH to a value of 2 to 4.2 while stirring at 150 to 1000 rpm for a period of 5 to 60 minutes at 5 °C to 20 °C;
and c) heating the emulsion or the gel from step a) to a temperature in the range of 35 °C to 45 °C while stirring and d) adding the shellac solution or dispersion from step b) while stirring at 150 to 1000 rpm for a period of 5 to 60 minutes at 35 °C to 45 °C;
and then e) cooling the resulting product to ambient temperature.

14. A method according to claim 13b, wherein the temperature is in the range of 5 °C to 15 °C.

15. A method according to claim 13b, wherein the pH is in the range of 2 to 3.5.