DE3912122A1 - UV absorbing chitin and chitosan derivs. - for use in hair and skin protection agents - Google Patents

Abstract

New UV-absorbing macromolecular cpds. derived from chitin or chitosan have the formula (I) in which X and Y = H, acetyl, benzoic acid residue of formula (II) or a cinnamic acid residue of formula (III) in which R1, R2 and R3 (same or different) = H, 1-4C alkoxy, OH or an amino gp. of formula N(R4)2 in which R4 = H, 1-4C alkyl, 2-4C monohydroxyalkyl or 2-4C dihydroxyalkyl, with the proviso that at least one of R1, R2 and R3 is other than H, and at most one of R1, R2 and R3 is N(R4)2, R5 = 1-4C alkoxy, and p = 3-20,000 with the proviso that Y is neither H nor acetyl if X = H. USE/ADVANTAGE - (I) are esp. useful as UV absorbing agents in hair-and skin care compsns. They are easily incorporated into suitable cosmetic bases such as creams, gels, dispersions, emulsions and aerosols, are physiologically harmless, adhere well to the skin and hair, and are not washed off by perspiration or water so that they offer good protection against the harmful effects of UV B-rays (280-320)nm.

Description

The invention relates to a cosmetic agent for treatment the hair and the skin, which is in a suitable Cosmetic base new macromolecular, from Chitosan or chitin-derived, UV-absorbing rays Contains compounds.

The invention further relates to new UV radiation absorbing Chitosan or chitin derivatives and a method for their production.

As is well known, when the human body is exposed to UV Radiation, such as intense solar radiation exposed becomes, an erythema of the skin. In certain cases This can even cause burning of the skin.

Responsible for the erythema is the so-called UV-B radiation having a wavelength of 280 to 320 nm has. In contrast, the so-called UV A radiation having a wavelength of 320 to 400 nm Tanning the skin without causing erythema.

The task of an effective sunscreen is Therefore, as selectively as possible the harmful UV-B Absorb radiation.  

This task will be supported by a variety of Derivatives of p-aminobenzoic acid, anthranilic acid, the Salicylic acid, cinnamic acid or benzophenone (so-called UV absorbers). The above low molecular weight compounds that have UV radiation in the Absorb area from 280 to 320 nm while covering for a UV radiation with a wavelength of 340 to 400 nm are permeable, usually meet the one to effective UV radiation filter provided physical chemical and application requirements, such as for example, light stability, odorlessness, adequate Solubility, good processability, compatibility with other cosmetic additives and stability the finished cosmetic preparation.

Although these compounds are generally toxicologically harmless, neither sensitizing nor allergenic be and have a good skin and mucous membrane compatibility, but arise again and again Doubts about their toxicological safety, since a, albeit slight, penetration of these compounds through the epidermis due to their molecular size is inevitable.

Another disadvantage of these low molecular weight UV absorbers is their low adhesion to the skin or the hair, so that it easily by water or sweat be washed off. It is therefore necessary to maintain a sufficient protective effect this UV absorbers constantly re-apply to the skin or hair apply.  

To eliminate this problem was in the literature recommended as UV absorbers certain polymeric compounds, the ones that stick well on the skin and hair, form against water and sweat resistant film. For example, in EP-OS 01 23 368 and DE-OS 37 10 222 recommended that certain, UV-absorbing Group-containing copolymers in sunscreens to be used as UV absorber. Also is it is known from US-PS 38 64 473, a poly (p-dialkyl aminobenzoylethyleneimine) as a UV absorber. The above-mentioned synthetic polymers have Although good UV-absorbing properties as well as a significant improved adhesion to the skin and the Hair, however, is the physiological compatibility these compounds due to their residual monomer content doubtful.

In JP-OS 62-1 98 609 it is recommended that the above described problem by using certain Polysaccharides to which UV absorbers are ionically adsorbed have been resolved. Such ionic compounds Although they have a relatively good adhesion to the skin and the hair, when in contact with water or sweat becomes However, the ionically adsorbed UV absorber by ion exchange removed from the connection. This becomes the one reduces the protective effect against UV rays, since the unbound UV absorber is easily washed out and physiological compatibility affected by these compounds containing agents.  

It was therefore the task of absorbing UV rays To provide compounds that are selective Absorption of UV rays in the range of 280 to 320 nm allow a good adhesion to the skin and the Own hair, not washed off by water and sweat are physiologically completely harmless and easy can be incorporated into cosmetic products.

For this purpose it has now been found that certain chitosan or chitin derivatives obtained by the reaction of chitosan or chitin with certain acylating reagents be, a selective absorption of UV rays in the Enable wavelength range from 240 to 340 nm and with the usual in skin and hair treatment products used ingredients are well tolerated. These Chitosan or chitin derivatives are replaced by water and Sweat only slightly from the skin and hair washed off and thus allow the production of Cosmetic products with a high and long lasting Protective effect against UV rays.

The subject of the present invention is therefore macromolecular derived from the chitosan of chitin Compounds of the general formula (I)

wherein
Y is hydrogen, acetyl, a benzoic acid radical of the formula (II) or a cinnamic acid radical of the formula (III),
and
X is hydrogen, a benzoic acid radical of the formula (II) or a cinnamic acid radical of the formula (III),

where in formula (II) the radicals R¹, R² and R³ are identical or different and are hydrogen, a C₁-C₄-alkoxy group, a hydroxy group or an amino group of the formula N (R⁴) ₂ where R⁴ is hydrogen, C₁-C₄-alkyl, C₂-C₄-monohydroxyalkyl or C₂-C₄-dihydroxyalkyl, under the condition that at least one of the radicals R¹ to R³ is different from hydrogen and at most one of the radicals R¹ to R³ represents an amino group of the formula N (R⁴) ₂,
in formula (III) R⁵ represents an alkoxy radical having from 1 to 4 carbon atoms in the alkyl chain, and p is an integer from 3 to 20,000, preferably an integer from 600 to 4,000, with the proviso that Y is neither hydrogen nor acetyl means when X is hydrogen.

Among the benzoic acid radicals of the formula (II), the following are particularly preferred:
4- (C₁-C₄alkoxy) -benzoyl, 2,4-di (C₁-C₄alkoxy) -benzoyl, 3,4,5-tri (C₁-C₄alkoxy) -benzoyl, 4-hydroxybenzoyl, 2- Hydroxybenzoyl and 4- [di (C₁-C₄alkyl) amino] benzoyl.

The new chitin or chitosan derivatives are obtained by having a chitin with 0 to 35 percent free amino groups or a chitosan, which consists of one to 65 to 100 percent deacetylated chitin exists with an acylating reagent in the appropriate ratio to the implementation brings.

As chitosan this is preferably a ground, low molecular weight chitosan with an intrinsic viscosity (Eta) - measured at 25 degrees Celsius in an aqueous Solution of 0.2 mol / l acetic acid and 0.1 mol / l sodium chloride - used by about 160 ml / g.

The reaction of chitosan or chitin with the acylating agent, which is preferably a carboxylic acid anhydride or a carboxylic acid halide, ("acylation") may done in 2 different ways. Either you solve that Chitosan or chitin at low temperature, preferably at about -5 to +5 degrees Celsius in methanesulfonic acid and then performs the acylation in homogeneous solution at about -5 to +5 degrees Celsius through; or you lead the acylation at about 20 to 40 degrees Celsius in one Dispersion of chitosan or chitin in an inert organic solvents, such as tetrahydrofuran, with the addition of an acid-binding agent, for example, pyridine, by.  

Suitable acylating agents are, for example, carboxylic acid halides and carboxylic acid anhydrides of o- or p- Dialkylaminobenzoic acids, for example p-dimethylaminobenzoyl chloride, Carboxylic acid halides and carboxylic acid anhydrides optionally substituted several times Alkoxybenzoic acids, for example 3,4,5-trimethoxybenzoyl chloride, Carboxylic acid halides and carboxylic acid anhydrides of hydroxybenzoic acids, for example salicylic acid chloride, or carboxylic acid halides and carboxylic acid anhydrides of p-alkoxycinnamic acids, wherein the carboxylic acid chloride and bromides are particularly preferred.

In the method according to the invention is the molar Ratio of the amount of chitosan or chitin used to the amount of acylating agent preferably 1: 1.5 to 1: 5.

By the two methods described above can absorb the UV rays of the invention Chitosan or chitin derivatives of the formula (I) in good However, to be noted is that in the second method due to the relative high reaction temperature a limited molecular Degradation and thus a slight reduction in molecular weight the chitosan or chitin derivatives takes place.

In the preparation of chitosan derivatives of the formula (I) (with Y = H) can be in the manner described above However, the free amino group of the. must be Chitosans before the reaction with the acylating agent by reaction with a removable protective group, for example, a benzylidene group blocked become.  

Chitin or chitosan derivatives of the formula (I) in which X and / or Y represent a cinnamic acid radical of the formula (III), can also be analogous to that in the JP-OS 60-2 19 202 described method become.

The thus obtained, sparingly soluble in water, but in organic solvents, for example alcohols, soluble chitosan or chitin derivatives have good film-forming properties, excellent adhesion on the skin and the hair as well as a good skin compatibility and are physiologically harmless.

The new chitosan or chitin derivatives enable a selective absorption of harmful UV-B rays in the Range from 260 to 320 nm while for the UV-A Radiation are permeable. Because of her good adhesion on the skin and the hair, the new chitosan- or chitin derivatives by water or sweat only in slightly washed off the skin and hair. If necessary, the new Chitosan or However, chitin derivatives readily by washing with aqueous Soap or surfactant solutions are removed.

Another object of the present invention is therefore a UV-protecting cosmetic for the treatment of the hair and the skin, which thereby characterized in that it is in a suitable cosmetic base a macromolecular, UV-absorbing, derived from chitosan or chitin compound of Contains formula (I).

The agent according to the invention preferably contains 0.1 to 25% by weight of the chitosan or chitin derivatives of Formula (I), wherein an amount of 0.5 to 15 weight percent is particularly preferred.  

The agent has a pH of 2 to 11, preferably from 4 to 7, and may take the form of an alcoholic or aqueous-alcoholic solution or as a cream, gel, dispersion or emulsion as well as in semi-solid to solid Form, for example, as a pen exist.

Alcohols are in particular those for cosmetic For purposes commonly used lower alcohols with 1 to 4 carbon atoms, such as ethanol, Propanol and isopropanol, into consideration.

It is also possible that this means in the form of a alcoholic or aqueous-alcoholic preparation is present and with the help of a nebulizer, respectively sprayed by other suitable spraying devices or mixed with a liquefied under pressure blowing agent is, is bottled in a pressure vessel and out of this in the form of an aerosol spray or foam.

Preferably, the inventive Means for treating the hair and / or the skin hair fixatives, tinting, hair sprays, hair gels, Hair lotions, hair conditioners, sunscreen creams, Sunscreen lotions, sunscreen or Sunscreen oils.

In addition to the UV-absorbing compounds of the Formula (I), these agents can be further, usually in additives used in such cosmetic products; such as anionic, cationic, amphoteric or nonionic surfactants foam synergists, Stabilizers, sequestering agents, humectants, Pearlescing agents, thickeners, opacifiers, Emulsifiers, buffer substances, preservatives, Dyes, pigments, perfume oils, natural, modified  natural or synthetic polymers, cosmetic oils, Fatty alcohols, waxes, foam stabilizers, combability improving Substances, antioxidants, hair and skin-care agents and propellants.

The above-described, protecting against UV rays cosmetic means forms on the skin and hair a closed, well-adherent, water-resistant Film with excellent protection against UV rays.

The following examples are intended to illustrate the subject matter of Explain the invention in more detail.  

Preparation Examples example 1 Preparation of 3,4,5-trimethoxybenzoyl chitin

From 20.3 g (0.09 mol) of chitin and 150 ml of methanesulfonic acid is a homogeneous with stirring at 0 to -3 degrees Celsius Solution prepared. Then, a solution of 115.3 g (0.50 mol) 3,4,5-trimethoxybenzoyl chloride in 300 ml Methanesulfonic acid at 0 to -3 degrees Celsius inside of 3 hours added dropwise with stirring. Subsequently, the reaction mixture for 2 hours stirred at 0 degrees Celsius and then with the help a dispersing rod (Ultra-Turrax) in a mixture from 6 l of water, 6000 g of ice and 300 ml of ammonia.

The fine flocculent precipitate is then over a G3 glass nutter separated, neutral with water washed and then at 50 degrees Celsius in a vacuum oven dried.

The crude product thus obtained is stirred with stirring in 250 ml Dissolved acetone, centrifuged and pressure filtered. Subsequently is the chitin ester by adding the Acetone solution reprecipitated in 4 l of diethyl ester, filtered off, washed with diethyl ether and then dried.

The yield of 3,4,5-Trimethoxybenzoylchitin is 39.6 g.  

Specifications Intrinsic Viscosity Number (Eta): 12 ml / g Substitution degree 3,4,5-trimethoxybenzoyl: 1.9 absorbed wavelength range: 240 to 320 nm

Example 2 Preparation of p-dimethylaminobenzoylchitosan

16.1 g (0.1 mol) of chitosan are mixed with 54 g (1 mol) Sodium methylate in 400 ml of methanol for 24 hours Room temperature stirred. Subsequently, the reaction mixture filtered, the residue with methanol neutral washed and then dried at 40 degrees Celsius in vacuo.

5.5 g (34 mmol) of the thus pretreated chitosan at room temperature (20-25 degrees Celsius) with 100 ml Pyridine added. Then, with stirring, in portions Added 18.4 g (0.1 mol) of p-dimethylaminobenzoyl chloride, giving a deep red coloration of the reaction mixture occurs. After a reaction time of 24 Hours at room temperature, the reaction mixture to Extraction of pyridine extracted with diethyl ether, then filtered, the resulting precipitate with diethyl ether washed and then at 40 degrees Celsius Vacuum dried.

The crude product thus obtained is dissolved in 800 ml of methylene chloride Stirred for 24 hours, filtered off, then at Dried at 40 degrees Celsius in a vacuum and then in Stirred 200 ml of water for 48 hours. The after the Filtration brownish, aqueous solution is washed with Help a degermination layer cleaned and vacuum so far concentrated that a highly viscous solution with a Content of 10 to 15 weight percent p-dimethylaminobenzoylchitosan is obtained.  

Specifications absorbed wavelength range: 280 to 340 nm Substitution degree p-dimethylaminobenzoyl: 0.1 to 0.3

The degree of substitution for the 3,4,5-trimethoxybenzoyl radical was determined by means of 1 H-NMR spectroscopy, while the degree of substitution for the p-dimethylaminobenzoyl radical was estimated using the UV spectrum.

The measurement of the limiting viscosity number (Eta) was carried out in Tetrahydrofuran at 25 degrees Celsius using a DIN Ubbelohde capillary viscometer.

The UV spectra (determination of the absorbed wavelength range) were measured with a spectrophotometer Beckmann company, type 24 in aqueous solution (example 2) or in methanolic solution (Example 1) added. The layer thickness was 1 cm in each case.

Examples of cosmetic products

Example 3 Sunscreen oil 3.0 g 3,4,5-Trimethoxybenzoylchitin according to Example 1 45.0 g Caprylic / capric 34.0 g 2-Octododecanol  18.0 g Caprylic / capric acid esters of saturated C₁₂-C₁₈ fatty alcohols 100.0 g

Example 4 Sunscreen in the form of an aerosol foam preparation 1.0 g 3,4,5-Trimethoxybenzoylchitin according to Example 1 5.0 g glycerin 5.0 g stearic acid 3.0 g triethanolamine 1.3 g myristic 1.3 g isopropyl 1.0 g silicone oil 1.0 g benzyl alcohol 0.5 g cetyl alcohol 0.3 g perfume oil  80.6 g water 100.0 g

Filling ratio:
90% active ingredient solution
10% propane / butane (50:50)

Example 5 Non-aerosol hair spray with UV protection 2.5 g 3,4,5-Trimethoxybenzoylchitin according to Example 1 88.8 g Ethanol (96%) 0.5 g ethoxylated lanolin 0.2 g perfume oil  8.0 g water 100.0 g

Example 6 Sunblock 16.00 g aqueous p-dimethylaminobenzoylchitosan solution according to Example 2 17.50 g cetyl alcohol 7.50 g Sorbitol (70% aqueous solution) 6.00 g polyoxyethylene 4.00 g Polyoxyethylene lanolin 2.50 g sorbitan 0.40 g perfume oil 0.15 g preservative  45.95 g water 100.0 g

Example 7 Sunscreen 32.3 g aqueous p-dimethylaminobenzylchitosan solution according to Example 2 45.5 g Ethanol (96%) 20.0 g polyoxyethylene 1.0 g carboxyvinyl 1.0 g triethanolamine  0.2 g perfume oil 100.0 g

Example 8 Lipstick with sun protection effect 1.0 g p-Methoxycinnamoylchitosan 37.5 g castor oil 20.8 g isopropyl palmitate 10.4 g myristyl 8.8 g Beeswax, bleached 7.3 g candelilla 5.7 g ozokerite 5.2 g Hydroxilated Lanolin 2.2 g pigments  1.1 g pearlescent 100.0 g

Example 9 Aerosol hair spray with UV protection 2.5 g p-Methoxycinnamoylchitin 47.1 g isopropanol 30.0 g n-butane 12.0 g isobutane 8.0 g n-propane 0.2 g diisopropyl 0.2 g perfume oil  80.6 g water 100.0 g

The percentages given in the present application unless otherwise stated, are by weight represents.

Claims (12)

1. UV rays absorbing macromolecular, derived from chitin or chitosan, compounds of the general formula (I) wherein
Y is hydrogen, acetyl, a benzoic acid radical of the formula (II) or a cinnamic acid radical of the formula (III), and
X is hydrogen, a benzoic acid radical of the formula (II) or a cinnamic acid radical of the formula (III), where in formula (II) the radicals R¹, R² and R³ are identical or different and are hydrogen, a C₁-C₄-alkoxy group, a hydroxy group or an amino group of the formula N (R⁴) ₂ where R⁴ is hydrogen, C₁-C₄-alkyl, C₂-C₄ monohydroxyalkyl or C₂-C₄-dihydroxyalkyl, under the condition that at least one of R¹ to R³ is different from hydrogen and at most one of R¹ to R³ is an amino group of the formula N (R⁴) ₂, in Formula (III) R⁵ represents an alkoxy radical having 1 to 4 carbon atoms in the alkyl chain, and
p is equal to an integer from 3 to 20,000,
with the proviso that Y is neither hydrogen nor acetyl when X is hydrogen. 2. A compound according to claim 1, characterized in that the benzoic acid radical of the formula (II) is selected is from 4- (C₁-C₄-alkoxy) benzoyl, 2,4-di (C₁-C₄- alkoxy) benzoyl, 3,4,5-tri (C₁-C₄ alkoxy) benzoyl, 4-hydroxybenzoyl, 2-hydroxybenzoyl and 4- [di (C₁-C₄-) alkyl) amino] benzoyl. 3. UV-protecting cosmetic agent for Treatment of the hair and the skin, characterized that it is in a suitable cosmetic basis a UV-absorbing, macromolecular, derived from chitin or chitosan compound according to Claim 1 or 2 contains.   4. Composition according to claim 3, characterized in that it as a UV-absorbing chitin or chitosan derivative a p-methoxycinnamoyl chitosan, a p-dimethyl aminobenzoyl chitosan, a p-methoxycinnamoyl chitin or a 3,4,5-trimethoxybenzoyl chitin. 5. Composition according to claim 3 or 4, characterized that it absorbs the UV-absorbing chitin or chitosan derivative in an amount of 0.1 to 25 Contains percent by weight. 6. Composition according to one of claims 3 to 5, characterized that it is in the form of an alcoholic or aqueous-alcoholic solution or as a cream, gel, dispersion or emulsion as well as in semi-solid or solid Form as a pen exists. 7. Composition according to one of claims 3 to 6, characterized that it is in the form of an alcoholic or aqueous-alcoholic preparation is present, with a mixed under pressure liquefied propellant, is filled in a pressure vessel and out of this taken in the form of an aerosol spray or foam becomes. 8. A process for the preparation of the compounds according to Claim 1 or 2, characterized in that one a chitin with 0 to 35% free amino groups or a chitosan consisting of one to 65 to 100% deacetylated chitin, with an acylating agent brings in a suitable ratio to the implementation.   9. The method according to claim 8, characterized the acylating agent is selected from carboxylic acid halides and carboxylic acid anhydrides of o- or p-dialkylaminobenzoic acids, alkoxybenzoic acids, Hydroxybenzoic acids or p-alkoxycinnamic acids. 10. The method according to claim 8 or 9, characterized that chitosan or chitin in methanesulfonic acid dissolves and at -5 to +5 degrees Celsius acylated. 11. The method according to claim 8 or 9, characterized that chitosan or chitin in one dispersed inert organic solvent and in Presence of an acid-binding reagent at 20 to 40 degrees Celsius acylated. 12. The method according to any one of claims 8 to 11, characterized characterized in that the molar ratio of the used Amount of chitosan or chitin to the amount Acylating agent 1: 1.5 to 1: 5.