WO1998027933A1

WO1998027933A1 - Use of 3-(n-butyl-acetamino)-ethyl propionate for improving the photostability of cinnamic acid derivatives

Info

Publication number: WO1998027933A1
Application number: PCT/EP1997/006883
Authority: WO
Inventors: Thekla Kurz; Sabine Hitzel; Dorothee Wille
Original assignee: Merck Patent Gmbh
Priority date: 1996-12-21
Filing date: 1997-12-10
Publication date: 1998-07-02
Also published as: DE19653892A1; AU5755798A

Abstract

The present invention relates to the use of 3-(N-butyl-acetamino)-ethyl propionate for improving the photostability of photoprotective filters belonging to the class of cinnamic acid derivatives in cosmetic preparations. The invention further relates to cosmetic preparations containing at least one photoprotective filter belonging to the class of cinnamic acid derivatives, whereby the photostability of said filter is improved by means of 3-(N-butyl-acetamino)-ethyl propionate. The invention also relates to a method for improving the photostability of photoprotective filters belonging to the class of cinnamic acid derivatives with regard to ultraviolet radiation in cosmetic formulations by the addition of an effective quantity of 3-(N-butyl-acetamino)-ethyl propionate.

Description

USE OF 3- (N-BUTYLACETAMINO) PROPIONIC ACID ETHYL ESTER TO IMPROVE THE PHOTOSTABILITY OF CINNAMIC DERIVATIVES

The present invention relates inter alia to the use of ethyl 3- (N-butylacetamino) propionate to improve the stability of light protection filters from the substance class of cinnamic acid derivatives against ultraviolet radiation in cosmetic formulations.

As is known, the skin is sensitive to the sun's rays, which can cause normal sunburn or erythema, but also more or less pronounced burns.

However, sun rays also have other negative effects: they cause the skin to lose its elasticity and wrinkles and thus lead to premature aging. Sometimes you can also see dermatoses. In extreme cases, some people develop skin cancer.

It is also desirable to protect hair against photochemical damage in order to prevent changes in color shades, discoloration or mechanical damage.

As is known, the most dangerous part of the sun's rays is formed by the ultraviolet rays with a wavelength of less than 400 nm. It is also known that due to the presence of the ozone layer in the earth's atmosphere, which absorbs part of the sun's radiation, the lower limit of the ultraviolet rays that reach the earth's surface is approximately 280 nm.

The problem with many sun protection preparations is, however, that many light protection filters are sensitive substances and have little stability to the ultraviolet rays; they decompose more or less quickly. This leads to problems with the durability or effectiveness of the corresponding cosmetic formulations. These preparations do not show any lasting effect with prolonged exposure to the sun, so that repeated use on the skin or hair is necessary.

The light protection filters of the substance class of cinnamic acid derivatives are well-known and widely used light protection filters, especially because they are an excellent solvent for many other light protection filters, which would otherwise not be soluble in sufficient quantities in the corresponding cosmetic formulations.

However, the stability of this class of substances also leaves something to be desired, and there is still a lack of substances which can be added to the formulations for stabilizing the light protection filters, but which do not otherwise adversely affect the action and the composition of the cosmetic preparations.

It therefore appears desirable to provide more stable cosmetic preparations with respect to the light protection filters, which contain at least one light protection filter from the substance class of cinnamic acid derivatives and which can absorb UV rays in a wavelength range from 280 to 400 nm, i.e. UVB rays with a wavelength between 280 and 320 nm, which play a decisive role in the formation of a sun erythema, as well as U VA rays with a wavelength between 320 and 400 nm, which tan but also age the skin Can trigger an erythematous reaction or increase this reaction in certain people or even trigger phototoxic or photoallergic reactions.

Today's sun protection filters in cosmetics are divided into UVA and UVB filters. For both UV ranges there are many well-known substances that are well-known from the specialist literature, for example only substances such as phenylbenzimidazole-5-sulfonic acid (Eusoiex ^® 232), benzophenone derivatives (Eusolex ^® 4360), Benzoyl or dibenzoylmethane derivatives (Eusolex ^® 9020 or Parsol ^® 1789, Eusolex 8020,), triazone derivatives (Uvinul T150 ^® ), salicylate derivatives (Eusolex HMS ^® , Eusolex OS ^® ), the benzylidene camphor derivatives (Eusolex ^® 6300) Octocyreles (Eusolex OCR ^® ), inorganic light protection filters from the group of titanium dioxide and zinc oxide.

However, it is also known that the light protection filters generally have only a relatively low solubility in the oils used in cosmetics, and therefore their filter potential cannot be fully exploited.

The substances of the cinnamic acid derivatives, in particular the p-methoxycinnamic acid octyl ester, often serve, in addition to the function as a light protection filter, as a solvent for other UV filters, and are therefore often used in combination with various filters.

Surprisingly, it has now been found that the light protection filters of the cinnamic acid class have a significantly higher photo stability in the presence of the substance 3- (N-butylacetamino) propionate.

The substance 3- (N-butylacetamino) propionic acid ethyl ester is known to have an insect repellent effect and is therefore incorporated into cosmetic formulations which are used to repel insects.

3- (N-Butylacetamino) propionic acid ethyl ester is usually incorporated into cosmetic formulations in concentrations of up to 30%. It is a very polar oil that differs from traditional cosmetic oils due to its miscibility with water and oils.

This substance also has the great advantage of not showing any toxic or allergic reactions to the skin. The formulations according to the invention can also be used for the preventive treatment of inflammation and allergies to the skin, for the prevention of certain types of cancer and also partly for repelling insects.

They are evenly distributed in the conventional cosmetic carriers and can form a continuous film, especially in fat carriers; they can be applied to the skin in this way to form an effective protective film.

EP 0 717 982 describes the increase in the photo stability of light protection filters based on the dibenzoylmethane derivatives by adding an effective amount of an amide compound. However, there is no indication that cinnamic acid derivatives could also be stabilized by such an amide compound as the ethyl 3- (N-butylacetamino) propionate.

The discovery according to the invention cannot be derived from the prior art by simple conclusion either, since other classes of substances, e.g. Derivatives of p-aminobenzoic acid or phenylbenzimidazole sulfonic acids cannot be stabilized by ethyl 3- (N-butylacetamino) propionate, but on the contrary, the stability of these substances even decreases in the presence of this substance.

The invention thus relates to the use of ethyl 3- (N-butyl-acetamino) propionate to improve the photostability of light protection filters, which belong to the substance class of cinnamic acid derivatives, in cosmetic formulations.

The invention also relates to a cosmetic preparation containing at least one light protection filter from the substance class of cinnamic acid derivatives, characterized in that ethyl 3- (N-butylacetamino) propionate is used to improve the photostability of this light protection filter. Another object of the invention is a process for improving the photostability of light protection filters of the substance class of cinnamic acid derivatives against ultraviolet radiation in cosmetic formulations, characterized in that an effective amount of 3- (N-butylacetamino) propionic acid ethyl ester is added to the corresponding formulation.

In a preferred embodiment, as light protection filters p- methoxycinnamate (Eusolex ^® 2292, Merck KGaA), isoamyl p-methoxycinnamate and / or diethanolamine-p-methoxycinnamate employed. Eusolex is particularly preferably used ^® 2,292th

The content of light protection filter in the cosmetic preparation according to the invention is preferably 0.01 to 40% by weight, a content of 1 to 20% by weight is very particularly preferred. Another very particularly preferred embodiment contains 3 to 10% by weight.

The content of 3- (N-butylacetamino) propionic acid ethyl ester, which additionally often serves as a solubilizer for further light protection filters, is preferably 0.1 to 90% by weight, particularly preferably 1 to 30% by weight.

The light protection filters of the cinnamic acid class can be present in the cosmetic formulations according to the invention alone or in combination with one or more UV filters of other substance classes, each of which is contained in an amount of 0.01 to 40% by weight, preferably 0.1 to 10% by weight can.

As the Eusolex ^® 2292, as already mentioned, is a very good solvent for other UV filters, it is preferably used in combination with other UV filters, which results in an increased total concentration of the light protection filter in the formulations. As already mentioned, the substance 3- (N-butylacetamino) propionic acid ethyl ester is known as an insect repellent. The insect repellent can be obtained commercially, for example from Merck KGaA, Darmstadt. Formulations obtained using this substance therefore have a very desirable one

Insect repellent effect.

The insect repellent shows such excellent properties as a very good skin and mucous membrane tolerance without toxic, allergenic or sensitizing properties.

Furthermore, the substance has a high chemical stability, i.e. no hydrolyzability, no photo-oxidizability, no oxidizability, high thermal stability and high welding resistance.

Furthermore, this substance is well tolerated and miscible with the common cosmetic and pharmaceutical formulation bases.

Due to its solubility profile, the substance mixes with oils and water, so it differs significantly from traditional cosmetic oils.

These properties now lead to a very high solubility of known light protection filters.

This is why the combination of ethyl 3- (N-butylacetamino) propionate with Eusolex ^® 2292 is so outstandingly suitable for incorporating further UV filters, which are otherwise only soluble in low concentrations, into the cosmetic preparations, plus an increased one Photo stability.

The invention further relates to a method for protecting the skin and / or naturally or sensitized hair from sun rays, a cosmetic preparation according to the present invention being applied to the skin or the hair. By "sensitized hair" is meant hair that has been subjected to a permanent wave treatment, a coloring or decolorization process.

If the cosmetic preparation according to the invention is used to protect human epidermis against UV rays, it is in various forms which are commonly used for this type. So it can in particular in the form of oily, oily-aqueous, aqueous-alcoholic or oily-alcoholic lotions, emulsions, such as cream or milk (W / O or O / W), in the form of oily-alcoholic, oily-aqueous or aqueous-alcoholic Gels or as solid sticks or powders or as a spray or aerosol.

The formulation according to the invention can contain further cosmetic adjuvants which are usually used in this type of preparation, such as e.g. Thickeners, plasticizers, wetting agents, surfactants, preservatives, anti-foaming agents, perfumes, waxes, lanolin, propellants, dyes and / or pigments that color the agent itself or the skin, and other ingredients commonly used in cosmetics.

An oil, wax or other fat body, a low monoalcohol or a low polyol or mixtures thereof can be used as the solubilizing agent. The particularly preferred monoalcohols or polyols include ethanol, i-propanol, propylene glycol, glycerol and sorbitol.

A preferred embodiment of the invention is an emulsion which is present as a protective cream or milk and, in addition to one or more sun protection factors and the 3- (N-butylacetamino) propionic acid ethyl ester, fatty alcohols, fatty acid esters, in particular triglycerides of fatty acids, fatty acids, lanolin, natural or synthetic oils or waxes and emulsifiers in the presence of water. Further preferred embodiments are oily lotions based on natural or synthetic oils and waxes, lanolin, fatty acid esters, in particular triglycerides of fatty acids, or oily alcoholic lotions based on a lower alcohol, such as ethanol, or a glycol, such as propylene glycol, and / or a polyol such as glycerin and oils, waxes and fatty acid esters such as triglycerides of fatty acids.

The cosmetic preparation according to the invention can also be in the form of an alcoholic gel which comprises one or more lower alcohols or polyols, such as ethanol, propylene glycol or glycerol, and a thickening agent, such as silica. The oily-alcoholic gels also contain natural or synthetic oil or wax.

The solid sticks consist of natural or synthetic waxes and oils, fatty alcohols, fatty acids, fatty acid esters, lanolin and other fat bodies.

If a preparation is packaged as an aerosol, the usual propellants, such as alkanes, fluoroalkanes and chlorofluoroalkanes, are generally used.

If a formulation is made up as a spray, usually aqueous-alcoholic solutions are used.

If the agent according to the invention is intended to protect natural or sensitive hair from UV rays, it can be in the form of a shampoo, lotion, mousse, gel or emulsion for rinsing out, the respective formulation before or after shampooing, before or after dyeing or decoloring or applied after the perm; or the agent is in the form of a lotion, mousse or gel for styling and treatment, as a lotion, mousse or gel for brushing or laying a water wave, as a hair lacquer, permanent wave agent, dye or decolorizer for the hair. In addition to the compound according to the invention, this agent can contain various adjuvants used in this agent type, such as surfactants, thickeners. agents, polymers, softening agents, preservatives, foam stabilizers, electrolytes, organic solvents, silicone derivatives, oils, waxes, anti-greasing agents, dyes and / or pigments that color the agent itself or the hair or other ingredients commonly used for hair care.

The cosmetic preparations according to the invention can be produced using techniques which are well known to the person skilled in the art.

Even without further explanations, it is assumed that a person skilled in the art can use the above description in the broadest scope. The preferred embodiments are therefore only to be understood as a descriptive disclosure, in no way as a limitation in any way.

The full disclosure of all applications, patents, and publications listed above and below are incorporated by reference into this application.

The following examples are intended to explain the invention in more detail.

Examples

Comparative example

In this example, the photostability of octyl p-methoxycinnamate was tested in the presence of ethyl 3- (N-butylacetamino) propionate and in comparison without this substance. The experiment was carried out as follows:

1. Preparation of ethanolic solutions with Eusolex® 2292 once with and the comparison solution without the substance according to the invention: Comparative solution:

% By weight

Eusolex® 2292 (item no.105382) d) 0.8%

Luviskol VA 37 E (2) 10.0%

Ethanol 99% (Item No. 100983) (1) ad 100.0%

Solution A

Eusolex® 2292 (item no.105382) (1) 0.8%

Luviskol VA 37 E (2) 10.0%

3- (N-Butylacetamino) propionic acid ethyl ester (1) 10.0%

(Item no.111887)

Ethanol 99% (Item No. 100983) d) ad 100.0%

Sources of supply:

(1) Merck KGaA, Darmstadt (2) BASF, Ludwigshafen

2. Coating a quartz plate with the above solutions: 0.5 ml in the doctor opening

Theoretical layer thickness = 25 μm drying time = 30 min.

Cover the plate with a second quartz plate and mask the edges.

3. Exposure:

Devices: Suntest CPS

Radiation limited to> 290 nm (UV special glass filter bowl) Radialux with UV sensor

Conditions: Irradiance E at 80 W / m2

(Potentiometer at maximum strength) 4. UV spectrum

Direct measurement of the double plates on the Shimadzu UV 260 after 15, 30, 60 and 180 minutes of exposure.

5. Result:

decomposition

Dose reference solution solution A

(W / m2)

0 0 0

25 34.4% 25.9%

50 45.0% 28.9%

100 60.8% 33.3%

300 83.1% 50.2% This experiment clearly shows that the addition of ethyl 3- (N-butylacetamino) propionate significantly increases the photo-stability of the octyl p-methoxycinnamate.

example 1

A pump spray of the following composition is produced:

% By weight

Ethyl 3- (N-butylacetamino) propionate (1) 25.00

(Item no.111887)

Eusolex® 2292 (item no.105382) (1) 5.00

Eutanol® G (2) 3 p.m.

Ethanol 96% (Item No. 100971) (1) ad 100.00

Perfume oil 72980 (3) 0.30

Manufacturing:

First dissolve Eusolex® 2292 in Eutanol® G, then add the remaining components while stirring and pour the whole thing into a suitable pump spray system. Sources of supply:

(1) Merck KGaA, Darmstadt

(2) Henkel, Dusseldorf

(3) Haarmann & Reimer, Holzminden

Example 2

An oil according to the invention for protection against UV rays is produced from the following components.

% By weight

Ethyl 3- (N-butylacetamino) propionate (1) 20.00

(Item no.111887)

Eusolex® 2292 (item no.105382) (D 7.00

Paraffin oil, thin (item no.107174) (1) ad100.00 Miglyol® 812 (2) 15.00

Cetiol® B (3) 22.50

Eutanol® G (3) 8.00

Manufacturing:

With stirring, all components are put together and heated until all components are dissolved. If necessary, at

Can be perfumed at 40 ° C.

Sources of supply:

(1) Merck KGaA, Darmstadt

(2) Hüls Troisdorf AG, Witten (3) Henkel, Düsseldorf

Example 3

A sun protection cream (W / O) according to the invention is produced from the following components.

% By weight

A 3- (N-butylacetamino) propionic acid ethyl ester (D 15.00

Eusolex® 2292 (item no.105382) (1) 7.00

Abil® EM 90 (2) 3.00

Jojoba oil (3) 4.00 Cetiol® B (4) 1.00

Prisorine 2021 (5) 2.00

Castor oil (6) 1.00

Lunacera® W 80 (7) 1.50 B glycerol (item no.104093) (1) 2.00 sodium chloride (item no.106400) d) 0.40

Preservatives q.s.

Water, demineralized ad 100.00

Preparation: Phase A is heated to 75 ° C and phase B to 80 ° C. Phase B is then slowly stirred into phase A, homogenized, and then cooled with stirring.

Sources of supply:

(1) Merck KGaA, Darmstadt (5) Unichema, Emmerich (2) Th. Goldschmidt, Essen (6) Heess, Stuttgart

(3) Lamotte, Bremen (7) fountain pen, Lüneburg

(4) Henkel, Dusseldorf

Example 4

A sun protection cream (W / O) according to the invention with a combination of different UV filters is produced from the following components. % By weight

A 3- (N-butylacetamino) propionic acid ethyl ester (1) 20.00

Eusolex® 4360 (item no.105844) (D 5.00

Eusolex® 6300 (Art-No. 5385) d) 6.00

Eusolex® 2292 (item no.105382) d) 5.00

Abil EM 90 (2) 3.00

Jojoba oil (3) 4.00

Prisorine 2021 (4) 2.00

Castor oil (5) 1.00

Lunacera W 80 (6) 1.50

B Glycerin (Item No. 104093) (1) 2.00

Sodium chloride (Item No. 106400) (1) 0.40

Preservatives q.s.

Water, demineralized ad 100.00

Manufacturing:

Phase A is heated to 75 ° C. and phase B to 80 ° C. Phase B is then slowly stirred into phase A, homogenized, and then cooled with stirring.

Sources of supply:

(1) Merck KGaA, Darmstadt (4) Unichema, Emmerich

(2) Th. Goldschmidt, Essen (5) Lamotte, Bremen

(3) Heess, Stuttgart (6) fountain pen, Lüneburg

Claims

PATENT CLAIMS

1. Use of ethyl 3- (N-butylacetamino) propionate in cosmetic formulations to improve the photo stability of light protection filters which belong to the substance class of cinnamic acid derivatives.

2. Use according to claim 1, characterized in that p-methoxycinnamic acid octyl ester (Eusolex ^® 2292, Merck KGaA) and / or isoamyl-p-methoxycinnamic acid ester and / or diethanolamine-p-methoxycinnamic acid ester are used as cinnamic acid derivatives.

3. Use according to claim 1 or 2, characterized in that the content of light protection filter in the cosmetic preparation is 0.01 to 40 wt .-%.

4. Use according to one of claims 1 to 3, characterized in that the content of ethyl 3- (N-butylacetamino) propionate is 0.1 to 90% by weight.

5. Use according to one of claims 1 to 4, characterized in that further light protection filters of different substance classes, individually or in combination, can be contained in the cosmetic preparation.

6. Cosmetic preparation containing at least one light protection filter of the substance class of cinnamic acid derivatives, characterized in that 3- (N-butylacetamino) propionic acid ethyl ester is used to improve the photostability of this light protection filter.

7. Cosmetic preparation according to claim 6, characterized in that p-methoxycinnamic acid octyl ester (Eusolex ^® 2292, Merck KGaA) and / or isoamyl-p-methoxycinnamic acid ester and / or diethanolamine-p-methoxy cinnamic acid ester are contained as cinnamic acid derivatives.

8. Cosmetic preparation according to claim 6 or 7, characterized in that the content of light protection filter is 0.01 to 40 wt .-%.

9. Cosmetic preparation according to one of claims 6 to 8, characterized in that the content of ethyl 3- (N-butylacetamino) propionate is 0.1 to 90% by weight.

10. Cosmetic preparation according to one of claims 6 to 9, characterized in that further light protection filters of different substance classes, individually or in combination, can be contained in the cosmetic preparation.

11. Cosmetic preparation according to one or more of claims 6 to 10 with an increased total concentration of contained

Sun protection filter.

12. Cosmetic preparation according to one or more of Claims 6 to 11 with an insect repellent effect.

13. A method for improving the photostability of light protection filters of the substance class of cinnamic acid derivatives against ultraviolet radiation in cosmetic formulations, characterized in that an effective amount of 3- (N-butylacetamino) propionic acid ethyl ester is added to the corresponding formulation.

14. The method according to claim 13, characterized in that p-methoxycinnamic acid octyl ester (Eusolex ^® 2292, Merck KGaA) and / or isoamyl-p-methoxycinnamic acid ester and / or diethanolamine-p-methoxycinnamic acid ester are used as cinnamic acid derivatives.

15. The method according to claim 13 or 14, characterized in that the content of light protection filter is 0.01 to 40 wt .-%.

16. The method according to any one of claims 13 to 15, characterized in that the content of ethyl 3- (N-butylacetamino) propionate is 0.1 to 90% by weight.

17. The method according to any one of claims 13 to 16, characterized in that further light protection filters of different substance classes, individually or in combination, can be contained in the cosmetic preparation.