CH634986A5 - Cosmetic light-stabilising agent for the UV-A region - Google Patents

Description

The invention relates to a cosmetic light stabilizer for the UV-A range with a content of cyclopentanone or cyclohexanone derivatives which, when applied topically to the skin, provide protection against the damaging effects of the longer-wave UV-A component of sunlight when exposed to prolonged exposure .

The preparations generally used as cosmetic sunscreens or light stabilizers contain components which prevent or reflect the short-wave UV-B component of sunlight to prevent sunburn. They reduce the dose of short-wave radiation that penetrates the outer layers of the skin and thus prevent the development of severe erythema without preventing the tanning caused by the longer-wave portion. This longer-wave portion of sunlight, which covers the range of 320-400 nm, not only enables pleasant tanning of the skin, but is also held responsible for the chronically damaged skin. This damage was formerly considered age-related, it was generally referred to as

30 aging skin. Today, however, it is known that they essentially depend on the total duration and intensity of the exposure to light. Such damage to the skin is manifested by increased wrinkling of the skin due to loss of elasticity, thinning of the epidermis, yellow-brown discoloration of the facial skin, pigment shifts and finally by keratoses, which can lead to cancer precursors and skin cancer, such as spinaliomas and basaliomas.

There is therefore a need, not only from a purely aesthetic point of view, for cosmetic agents which prevent the harmful side effects of too long and intensive exposure to the longer-wave UV-A component of sunlight. The agents must also be toxicologically and dermatologically harmless, have good light and heat stability and adhere well to the skin.

It has now been found that a cosmetic light stabilizer containing cyclopentanone or cyclohexanone derivatives of the formula

O

ti

(I)

0

II

(II)

respectively,

R-H0 ^ /

in which n is the number 2 or 3 and R is the radical Ar or -CH = CH-Ar, where Ar is an aryl radical, in particular a phenyl radical, which may be one or more C1-C4-alkyl radicals, one or more hydroxyl groups ^), one or more Ci-C4-alkoxy group (s), one or more amino or DHQ-CJ-alkylaminogrup-

pe (n), one or more halogen atom (s) or a methylenedioxy group is substituted, the 65 requirements largely met.

The cyclopentanone or cyclohexanone derivatives used in the cosmetic light stabilizer according to the invention can be prepared according to methods known from the literature.

drive by condensation of the corresponding cyclic ketone with an aromatic aldehyde under alkaline conditions. This can be done by dissolving the cyclic ketone and aromatic aldehyde together in a solvent and adding a base to the solution. But you can also first put the cyclic ketone and the base in a solvent and then add the aromatic aldehyde to the mixture. The condensation of the reactants can take place at low temperatures, such as room temperature and below, or can only be carried out at higher temperatures. The required reaction temperatures and general reaction conditions depend on the chemical constitution of the reactants and are easy to determine.

In order to obtain the cyclopentanone or cyclohexanone derivatives of the formula (II), a weight ratio of the reactants of aromatic aldehyde to cyclic ketone of 2: 1 is expediently chosen, the cyclic ketone having to be unsubstituted on the carbon atoms adjacent to the carbonyl group. If, on the other hand, it is desired to prepare a cyclopentanone or cyclohexanone derivative of the formula (I), a weight ratio of the reactants of aromatic aldehyde to cyclic ketone of 1: 1 or a slight excess of aromatic aldehyde is expediently used. Furthermore, it is generally necessary to modify the cyclic ketone so that a condensation reaction can only take place on one of the carbon atoms adjacent to the carbonyl group in order to avoid the formation of by-products of the formula (II). This modification can be carried out by reacting the cyclic ketone with morpholine to give an N- (l-cycloalkenyl) morpholine. This substituted morpholine can then condense with the aromatic aldehyde and then the condensation product obtained under acidic conditions to the desired cyclopentanone or. Cyclohexanone derivative of the formula (I) are cleaved.

For economic reasons, the base used in the condensation reaction is generally an alkali hydroxide, in particular sodium hydroxide.

As cyclopentanone or cyclohexanone derivatives which can be used in the cosmetic light stabilizer according to the invention are, for example 2-benzylidene cyclopentanone, 2-benzylidene cyclohexanone, 2- (4'-chlorobenzylidene) cyclopentanone, 2- (4'-methylbenzylidene) cyclopentanone, 2- (p-dimethylaminobenzylidene) cyclopentanone, 2-anisylidene cyclopentanone, 2- (p-hydroxybenzylidene) cyclopentanone, 2- (3 ', 4'-dimethoxybenzylidene) cyclopentanone, 2- (3'-hydroxybenzylidene) cyclopentanone, 2- (3', 4'-diethylbenzylidene) cyclopentanone , 2- (4'-aminobenzylidene) cyclopentanone, 2-anisylidene cyclohexanone, 2- (4'-chlorobenzylidene) cyclo-hexanone, 2- (p-dimethylaminobenzylidene) cyclohexanone, 2- (3 ', 4'-dichlorobenzylidene) -cyclohexanone, 2- (p-hydroxy-benzylidene) -cyclohexanone, 2- (3 ', 4'-dibutylbenzylidene) -cyclohexanone, 2,5-dibenzylidene cyclopentanone, 2,5-bis- (3'-dichlorobenzylidene) -cyclopentanone, 2,5-dianisylidene cyclopentanone, 2,5-disalicylidene cyclopentanone, 2,5-bis (3'-meth-oxy-4'-hydroxybenzylidene) cyclopentanone, 2,5-bis (p-hy-hydroxybenzylidene) - cyclopentanone, 2,5-dipiperonylidene-cyclopentanone, 2,5-bis- (3 ', 4'-dimethoxy-benzylidene) -cy-clopentanone, 2,5-dicinnamylidene cyclope ntanone, 2,6-bis (2 ', 3'-dimethoxy-benzylidene) cyclohexanone, 2,6-di-benzylidene cyclohexanone, 2,6-dianisylidene cyclohexanone, 2,6-bis (3', 4'-dimethoxybenzylidene ) -cyclohexanone, 2,6-bis- (p-dimethylaminobenzylidene) -cyclohexanone, 2,6-bis- (4'-iso-butylbenzylidene) -cyclohexanone, 2,6-bis- (3'-methoxy-4'- hydroxybenzylidene) cyclohexanone, 2,6-bis (3'-isopropyl)

3,634,986

benzylidene) -cyclohexanone, 2,6-bis- (p-aminobenzylidene) -cyclohexanone, 2,6-bis- (4'-ethylaminobenzylidene) -cyclo-hexanone.

When used in cosmetic light stabilizers, the cyclopentanone or cyclohexanone derivatives described can be incorporated into liquid, pasty or solid cosmetic preparations, such as aqueous solutions, aqueous suspensions, emulsions, solutions in organic solvents, oils, ointments, creams, sticks io or powder. When used as a light stabilizer against the longer-wave UV-A radiation, the cyclopentanone or cyclohexanone derivatives are used, for example, in a proportion of 0.5 to 20% by weight, preferably 2 to 10% by weight, based on the entire batch of kosmeti-15 see means used.

In addition to the sole use in cosmetic light stabilizers, the use in common with conventional UV-B filter substances which serve to prevent sunburn can be in the foreground of use. In this application, the cyclopentanone or cyclohexanone derivatives described can be used in combination with conventional UV-B filter substances, such as, for example, ethyl p-aminobenzoate, propyl ester, butyl ester, isobutyl ester, mono-glycerol ester, p-dimethylaminobenzoic acid ethyl ester , 25 -amyl ester, p-diethylaminobenzoic acid ethyl ester, -amyl ester, salicylic acid ethyl ester, -homomenthyl ester, -ethylene glycol ester, -glycerol ester, -2-ethylhexyl ester, -tert.butyl ester, -bornyl ester, -phenyl ester, triethanol-ammonium salt-antioxidant salt of salanic acid ester, -bornyl ester, p-methoxycinnamic acid-3-ethoxyethyl ester, -2-ethylhexyl ester, p-acetamido cinnamic acid isopropyl ester, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy- 4-n-octoxy-benzophenone, 4-phenylbenzophenone, 2-hydroxy-4-methoxy-35-benzophenone-5-sulfonic acid, 4-phenyl-benzophenone-2-car-bonic acid isooctyl ester, 7-ethylamino-4-methyl -coumarin, 7,8-dihydroxycoumarin, 6,7-dihydroxycoumarin, 7-Hy-dr oxyeumarin, 4-methyl-7-hydroxycoumarin, 2-phenyl-benzimidazole-5-sulfonic acid, sodium 3,4-dimethoxyphenyl-4o glyoxylate, butylbenzalacetone, benzalacetophenone, 3-benzylidene-D, L-camphor, 3- ( p-methylbenzylidene) -D, L-cam-pher and urocanic acid can be used.

The amount of UV-B filter substances in these products based on a combination of UV-A and UV-B protective substances 45 is, for example, 1 to 10% by weight, preferably 2 to 6% by weight, based on the entire cosmetic sunscreen.

When applied topically, such sunscreens not only provide effective protection against the feared sunburn, but also against the chronic effects of longer-lasting effects of the longer-wave UV-A components of sunlight.

The following examples are intended to demonstrate the protective properties of the cyclopentanone or 55 cyclohexanone derivatives described and their suitability for use in cosmetic light stabilizers.

The cyclopentanone or cyclohexanone derivatives were prepared by methods known from the literature, such as those e.g. are specified in DE-OS 2 245 518. 6o The preparation of the new compound 2,6-bis- (2 ', 3'-dimethoxybenzylidene) -cyclo-hexanone is listed below, for example.

Preparation of 2,6-bis (2 ', 3'-dimethoxybenzylidene) cyclo-65 hexanone

36.6 g of 2,3-dimethoxybenzaldehyde and 9.8 g of cyclo-hexanone were dissolved in 200 ml of methanol. After adding a solution of 10 g caustic soda in 45 ml water, the

634 986

4th

Mixture kept at 35-45 ° C with stirring for 1 hour. 39 g of a yellow condensation product separated out. After recrystallization from ethanol, the following analytical values were obtained:

% calculated: C 73.1 H 6.6 0 20.3% found: C 73.5 H 6.1 0 20.4

Analogously to the information in DE-OS 2 245 518, the following compounds were prepared for testing in light stabilizers. In addition to the name of the products, the absorption characteristics are listed in Table 1 below.

Table 1

Product 2 max. 1 g

(nm)

1

2-anisylidene cyclopentanone

327

4.2

2nd

2,5-bis (3'-methoxy-4'-hydroxybenzylidene) cyclopentanone

345

4.5

3rd

2- (3 ', 4'-Dimethoxybenzylidene) cyclopentanone

345

3.8

4th

2,5-dibenzylidene cyclopentanone

354

4.4

5

2,5-dianisylidene cyclopentanone

390

4.6

6

2,5-disalicylidene cyclopentanone

391

4.5

7

2- (p-dimethylaminobenzylidene) cyclopentanone

393

4.5

8th

2,5-bis (p-hydroxybenzylidene) cyclopentanone

397

4.3

9

2,5-dipiperonylidene cyclopentanone

400

4.5

10th

2,5-bis (3 ', 4'-dimethoxybenzylidene) cyclopentanone

403

4.6

11

2,5-dicinnamylidene cyclopentanone

407

4.7

12

2-anisylidene cyclohexanone

316

4.0

13

2,6-bis (2 ', 3'-dimethoxybenzylidene) cyclohexanone

319

4.4

14

2,6-dibenzylidene cyclohexanone

327

4.4

15

2,6-dianisylidene cyclohexanone

358

4.4

16

2,6-bis (3 ', 4 / -dimethoxybenzylidene) cyclohexanone

372

4.4

17th

2- (p-dimethylaminobenzylidene) cyclohexanone

328

4.3

Some examples of embodiments of the cosmetic light stabilizer according to the invention containing cyclopentanone or cyclo-hexanone derivatives are listed below:

Examples

1. To produce a light protection oil, 80 g of 2,5-dibenzylidene-cyclopentanone are very finely suspended in 100 g of paraffin oil with heating, and then the following further constituents are added at about 25 ° C.

300 g vegetable oil containing lecithin 400 g olive oil 100 g isopropyl myristinate 100 g purcellin oil mixed intimately.

2. To make a sunscreen powder

150 g of 2,6-dibenzylidene-cyclohexanone in a powder mixer intensively mixed with 350 g of rice starch, 350 g of colloidal clay, 100 g of lycopodium and 100 g of talc.

3. To make a sunscreen cream

40 g glycerol monostearate 160 g beeswax 420 g mineral oil

50 g of ceresin

50 g of an absorption base based on cholesterol, beeswax, stearyl alcohol and petroleum jelly

90 g of 2-anisylidene-cyclopentanone melted together at 65 ° C. In this warm mixture is a mixture heated to the same temperature

247 g water 35 13 g borax

2 g of methyl p-oxybenzoate are incorporated with vigorous stirring, and the cream obtained is stirred further until room temperature is reached.

40 4. To prepare a light protection emulsion, 70 g stearic acid 30 g oleic acid 4s 20 g cetyl alcohol in a mixture of 20 g glycerol monostearate heated to approx. 80 ° C

80 g of 2,6-dianisylidene-cyclohexanone are added to a mixture of 800 g of water, 10 g of glycerol and 9 g of triethanolamine with vigorous stirring. The lotion obtained is then stirred cold.

The above emulsion can also be packaged using a propellant in a volume ratio of 80 parts of lotion: 20 ss parts of propellant in aerosol form.

5. To make a sunscreen oil

80 g of 2- (3 ', 4'-dimethoxybenzylidene) -cyclopentanone 40 g of 2-ethylhexyl p-methoxycinnamate while heating is very finely suspended in 100 g of paraffin oil, and 6o thereafter at about 25 ° C. with the following further constituents

300 g vegetable oil containing lecithin 360 g olive oil 100 g isopropyl myristate 65 100 g purcellin oil mixed intimately.

6. To make a sunscreen

40 g glycerol monostearate

5

634 986

150 g beeswax 390 g mineral oil 50 g ceresin

50 g of an absorption base based on cholesterol, beeswax, stearyl alcohol and petroleum jelly

90 g 2,5-bis (3'-methoxy-4'-hydroxybenzylidene) -

cyclopentanone 40 g of 3- (p-methylbenzylidene) -D, L-camphor melted together at 65 ° C. A mixture of 247 g of water and 13 g of borax heated to the same temperature is added to this warm mixture

2 g of methyl p-oxybenzoate are incorporated with vigorous stirring, and the cream obtained is stirred further until room temperature is reached.

7. To prepare a sunscreen emulsion, 70 g of stearic acid and 30 g of oleic acid are added to a mixture of 20 g of glycerol monostearate heated to approximately 80 ° C.

20 g cetyl alcohol

80 g 2,6-bis (3 ', 4'-dimethoxybenzylidene) cyclohexa-non

40 g p-dimethylaminobenzoic acid 2-ethylhexyl 5-ester with vigorous stirring a mixture of 800 g water

10 g glycerol 9 g triethanolamine io given. The lotion obtained is then stirred cold.

The above emulsion can also be packaged using a propellant in a volume ratio of 80 parts lotion: 20 parts propellant in aerosol form.

Instead of the cyclopentanone or cyclohexanone derivatives used in the aforementioned formulations, the other cyclopentanone or. Cyclohexanone derivatives are used, and the 20 UV-B filter substances listed in the recipes can also be substituted for the other UV-B filter substances listed.

s

Claims (2)

634 986 2nd PATENT CLAIMS 1. Cosmetic light stabilizer for the UV-A range, characterized in that it is at least one cyclopentanone or cyclohexanone derivative of the formula 0 (II) R-HCx C. -CH-R \ / \ / or C C (CH_) J 1 n where n is the number 2 or 3 and R is the radical Ar or -CH = CH-Ar, where Ar is an aryl radical, which may be one or more Cj-C4-alkyl radicals, one or more Hydroxyl group (s), one or more QQ-alkoxy groupCn), one or more amino or di- (Ci-C4) -alkylamino group (s), one or more halogen atom (s) or a methylenedioxy group is substituted . 2. Light stabilizer according to claim 1, characterized in that it contains the cyclopentanone or cyclohexanone derivative in a proportion of 0.5-20 wt .-%, preferably 2-10 wt .-%, based on the total weight of the agent. 20 3. Light stabilizer according to claim 1 or 2, characterized in that it also contains UV-B filter substances in a proportion of 1-10 wt .-%, preferably 2-6 wt .-%, based on the total weight of the agent . 25th