EP1482906A1

EP1482906A1 - Astringent substances as sun protection products, especially for protecting against the uv radiation and infrared radiation of sunlight

Info

Publication number: EP1482906A1
Application number: EP01274941A
Authority: EP
Inventors: Gerhard Prof.Dr. Weber
Original assignee: Individual
Current assignee: Individual
Priority date: 2001-11-15
Filing date: 2001-11-15
Publication date: 2004-12-08
Also published as: WO2003049714A1; AU2002218299A1

Abstract

The invention relates to the use of astringent substances for preventing damaging effects caused by sunlight, and as sun protection products for human skin.

Description

Astringent substances as sunscreens, especially against UV radiation and infrared radiation from sunlight

The invention relates to the use of astringent substances as sunscreens. Sunscreens in general serve to protect human skin against the pathological effects of sun rays. The pathological sun reaction of human skin is understood to be reddening of the skin (erythema solare), sunburn (second-degree burn = microscopic or macroscopic blistering), premature aging of the skin (presenile skin atrophy), cornification (light keratosis) and skin cancer (basalioma, spinalioma, mela- nom). Since the studies by Fitzpatrick (Fitzpatrick, TB, et al. "Sunlight and Man", Univ. Of Tokyo Press, Japan 1974), it has been generally accepted that such pathological skin changes differ in type by the short or long-term exposure to UV - Radiation from the sun are caused, whereby the skin type of the person is decisive for the reactivity, d. H. Response time and type of response to be held responsible.

As an argument for the alleged predisposition of the white breed (caviar), their light, low-pigment skin is given, which is defenseless against sunlight due to its lack of melartin, in contrast to dark pigmented skin and its sun tolerance. A distinction is made between six skin types. So-called sunscreens and sunscreens have been developed and marketed worldwide to prevent such skin damage from sunlight. A distinction is made between physically effective and chemical sunscreens. Physical sunscreens mainly consist of minerals, they reflect them Sun rays and are intended to prevent radiation penetration into human skin. They are derived from the painting of the Australian Aborigines, but have practically no market significance, since it is not cosmetically justifiable to achieve an effective protective layer.

Chemical sunscreens are derived from p-aminobenzoic acid and its derivatives, but cinnamic acid derivatives and benzophenone are also used. The market volume of chemical sunblockers in Germany has been in the hundreds of millions for years, which indicates their spread among the population.

Nonetheless, medical statistics, specialist dermatological publications and the general press not only mention the dangers of sun exposure, but also point out that the number of sun cancers caused by the sun has doubled repeatedly.

The "sunscreens" have in common the absorption of UVA and / or UVB in different intensities. Their protective effect is determined and specified using the standard term "protection factor" or SPF (Colipa, "SPF Test Method", The Europe Cosm. Toilt. A Perfume Ass., Brussels, Belgium 1989; Rohr, M., Schrader, K., "The Determination of the Sun Protection Factor According to COLIPA, Perfume and Cosmetics, 1998, 5: 5 - 12). After initially used protection factors" 2 "or" 3 "in the fifties and sixties of the last century," sunscreens "with a factor of" 30 "to" 50 "are now commercially available, which proves that the so-called sun protection effect of these products is not sufficient for real sun protection of human skin. From these facts there are further contradicting findings: The "lighter" or the color The looser the surface of a medium with a liquid or solid consistency, the less it absorbs radiation for longer than 300 nm, the darker, more colored it is (e.g. black), the more its surface absorbs the radiation. Contrary to Fitzpatrick's thesis (Fitzpatrick, ibid.), This leads to the conclusion that the light skin, which is low in pigment, absorbs less radiation from the sun than that from the black.

In an examination of the behavior of the sun in rural African blacks it was demonstrated (Weber, G., "The skin color no longer matters", TW Dermatologie, 1994, 24, 78 - 83) that they are just as intolerant of the sun at the end of winter as Caucasians that only the erythema solar in the former is not equally recognizable as reddening of the skin because of the basic color of their skin, but the systemic reaction of "sunstroke" (intracranial pressure symptoms) manifests itself more strongly in black than in the Caucasian. The consumption of "sunscreens" by colored people corresponds (in South Africa) quantitatively to that of the Caucasians.

The doctrine of the carcinogenic effects of UVA or / and -B is invalidated by the following facts. There is no experimental study that carcinoma of human skin arises from exposure to UVA- or - B or UVAB alone. The worldwide therapeutic use of UVA, even with the use of light sensitizers such as 8-methoxypsoralen, for about 40 years, has just as little led to the development of carcinomas as the use of the sunbeds, which have existed for as long. Their UVB radiation component is 4%, in sunlight 2%. Although the significantly higher UV radiation intensity has no proven carcinogenicity when used in apparatus, the 2% UVB radiation component of sunlight is not only carcinogenicity, but also the provocation of malignant melanoma, which is contradictory. In a ten-year study by the US Navy (Garland, F. et al., "Occupational Sunlight Exposure on Melanoma in the US Navy", Arch. Environ. Health, 1990, 45, 5, 261 - 266) suffered (to 100,000 each Persons) 10.6% of the below-deck staff have melanoma, but 7% of the staff on and below deck.

Overall, these arguments show that neither UV radiation nor UV-blocking light stabilizers have a pathogenic or preventive effect on human skin. Nevertheless, the cause of light damage to the skin up to carcinoma by the sun is undisputed.

The largest share of global radiation (about 70%) is the infrared (LR) together with the heat-transporting colors. In contrast to UV radiation, evidence and arguments have long been available for the carcinogenic effects of IR (Weber, ibid; Weber, G., sun protection factor increases the risk of skin cancer, hautnah derm, 1995, 11, 139 - 144; Weber, G "Tanning - Not Burning", close up derm, 1997, 2, 2 - 5, Wiskemann, a. Et al., "Connective Tissue and Carcinogenesis by radiant heat", 2 ^nd Congress Europ. Soc. Photobiol., Sep. 1987 , Padova, Italy). The fact that none of the commercially available UV blockers has a protective effect against heat radiation explains their failure as prevention of the long-term sun damage. Therefore, the rapid increase in carcinomas and melanomas - despite the intensive use of light stabilizers and education of the population - is also due to the erroneous assumption that the sun protection factor X enables an X-times longer stay in the sun without risk. In fact, it follows that the factor with the optional carcinogenic heat radiation is increased by this factor X. (Weber, ibid.).

No. 5,804,164 discloses pharmaceutical compositions for protecting and treating sun-damaged skin which contain at least one anti-oxidant, at least one anti-inflammatory agent and at least one immune-promoting component. It is further disclosed that these compositions can contain one or more plant extracts in a small proportion. In this context, a ginkgo biloba extract is mentioned as a component of the compositions, which contains, among other things, tannin. Nothing can be gathered from US 5,804,168 about the proportion of tannin in the extract. The therapeutic dose of the composition for preventing or treating UV damage to the skin is disclosed to range from 1 mg to about 2000 mg when administered orally. Although topical administration is generally disclosed, the proportion of the active ingredient composition in a composition for topical application is not disclosed. In addition, however, a preventive effect of the composition after oral administration is only disclosed as an increase in the sun protection factor of sun protection agents. US Pat. No. 5,804,168 focuses entirely on damaging the action of UV rays and does not mention IR rays at any point.

EP 0 699 443 discloses an elder bark infusion for the treatment of burns and erythema caused by the sun. One of the more important components of the bark is tannin, among others. However, EP 0 699 443 relates only to the treatment of corresponding skin damage and contains no reference to the prevention of skin damage caused by sunlight. JP 10 087469 describes the use of tannin in combinations with titanium dioxide, mica coated with titanium dioxide and zinc oxide, each component being in a ratio of 0.025 to 0.05 parts by weight per 1 part by weight of the component consisting of the aforementioned metal compounds. The absolute amount of the aforementioned components in a usable preparation is disclosed. The disclosure also focuses solely on the protective effect against UV rays by light scattering.

Chemical Abstracts 129: 72399 (1998) also shows the use of tannic acid for the treatment of erythema of the skin caused by UV radiation. A preventive use of tannic acid is not disclosed.

Bangha E. and Eisner P .: Skin Problems in sugar artists. In: British Journal of Dermatology, 1996, Vol. 135, No. 5, pages 772-74 (Me (Eine Abstracts 97132223) disclose the treatment of, among other things, erythema with a preparation which contains 10% aluminum chloride hexahydrate. However, this has been the case Thermally induced erythema was reduced in only 7% of the test persons.This article also does not indicate any preventive effects of aluminum chloride hexahydrate or another astringent substance.Furthermore, this article contains no indication of damage prevention.

The invention is therefore based on the object of providing light protection which develops an effective local prophylaxis against the effect of light and the pathogenic effect of light on human skin and at the location of its application a preventive protection against the pathological provides solar radiation.

This object is achieved by using astringent substances according to the appended claim 1. Further, preferred configurations are the subject of the dependent claims.

It has been known since the 1920s that human skin thickens under the action of tanning (Guillaume, A., "Lichtschwiele", Bull. Soc. Med. Hop. Paris, 1926, 42, 1133), in that the cells of the homolayer - the uppermost layer of skin - increase, which is called "light calluses". The normal, ie not thickened, skin layer of the skin (approx. 25 μm) absorbs 20% UVA, 55% UVB and 70% IR (Raab, W. Lichtfiebel, ". Ed. 1990, Gustav Fischer, Stuttgart, New York), from which It can be seen that their thickening, the swell of light, largely prevents the sun's radiation from penetrating into deeper, germinative skin cells, which also explains why the skin's tolerance to the sun increases with the sun's habit (ie, the swell of light).

In the animal kingdom, too, the calluses serve to protect against heat radiation. In order to artificially produce a callus to protect the human skin from the effects of the heat rays of the sun, the invention proposes the use of astringent substances. “Astringents are substances that, when exposed to mucous membranes (and wounds), cause a seal and slight shrinkage of the tissue due to protein falling on very superficial layers. They are indicated for the local treatment of inflammatory mucous membranes "(Kuschinsky, G. et al., Pharmacology and Toxicology, Georg Thieme Verlag, Stuttgart, New York, 1981). A distinction is made between two groups: tannin-based, vegetable extracts on the one hand and dilute solutions of metal salts (e.g. AgN0 ₃ ) on the other.

The use of astringent substances according to the invention does not affect the mucous membrane or wounds and is not a therapeutic agent. The application of astringent copies according to the invention has the task of preventing penetration, e.g. B. to reduce the heat radiation of the sun in the layer of the human skin so that it results in a sunscreen against the penetration of solar radiation into the germinative epidermis. The detection of the heat radiation-inhibiting effect of astringent copies as an object according to the invention is described below.

Brief description of the figures

Show it:

1 shows a schematic representation of processes on the skin surface which take place when irradiated with electromagnetic waves;

Fig. 2 reflectance spectra of the skin;

Fig. 3 reflectance spectra similar to Fig. 2;

FIG. 4 reflectance spectra similar to FIGS. 2 and 3;

5 comparative reflectance spectra; and Fig. 6 is a schematic representation of the regression of a radiation erythema.

method of investigation

If electromagnetic radiation hits the surface of the skin, as shown in FIG. 1, various physical processes will take place. The radiation that has penetrated the epidermis can be measured as remission if it is not required by the human (supercooled) organism. The less heat absorption a person needs, the more he radiates the absorbed heat again. All solar radiation, including UVA and -B, is processed as heat in the organism. With the measurement of their reflectance, the reflection is also determined at the same time. The measurements are carried out with a reflectance spectrophotometer. These are divided into two areas, the excitation of the sample for remission and the registration of the remitted radiation. Two xenon short-arc lamps (model LPS 220) for excitation and irradiation with UV, visible and IR radiation (800 - 2500 µm) with a maximum output of 75 watts generate a continuous spectrum of UV over visible light and IR. The radiation from one xenon lamp is spectrally broken down in the double-grating monochromator (model 102). The radiation from the second xenon lamp is divided into two beams by means of an Indo-1 dichroic (mirror 455 nm, bandpass filter 485/10 nm and 405/10). A BaS0 spectrum is recorded as a measure of 100% skin remission, with which all remission spectra are corrected. The remission effect consists of absorption and remission of the incident radiation. The SPF is determined according to Colipa (ibid.). The subjects were selected according to Fitzpatrick (ibid.). In addition to the usual UV evaluation in the Colipa test, the The task of determining the IR according to the invention using the second xenon arc lamp compared the radiation effect of UV, visible light and IR.

Testing, application and results of the investigation of astringent substances according to the invention

The study of astringent substances according to the invention had the task of showing what light-protecting properties they have using the example of tannin and tamol (synthetic tannins) for comparison with aluminum lactate, aluminum chlorohydrate and Colipa standard.

The remission measurements were carried out on the back of 10 test subjects and averaged twice per measurement. Fig. 2. shows the reflectance spectra of the skin before and after application of the standard and 5%

Tannin. 3 and 4. show that the tannin alone causes an increase in absorption at about 320 nm and in the IR. In contrast to placebo and tamol, the use of a tannin solution for 14 days shows a constant increase in absorption, but no strengthening (FIG. 5).

The examination of the regression of the radiation erythema in 20 test subjects by tannin in comparison with the placebo showed a significantly faster decay of the erythema by tannin, which shows the preventive protective effect of tannin (FIG. 6).

Examples of other astringent substances and model recipe

As the basic formulation of an emulsion, as it is basically the person skilled in the art is known, the following composition was used in the investigations described above:

Paraffinum perliquidum 15.0% by weight

Pentylene glycol 5.0% by weight

Cetearyl alcohol 3.3% by weight

DEA cetyl phosphate 2.0% by weight

Disodium EDTA 0.1% by weight

Water rest

This basic formulation was used as a placebo, while comparisons were carried out with model formulations which additionally contained 3 or 5% by weight of tannin as an astringent substance.

As examples of further astringent substances which can be used in the context of the present invention, aluminum acetate, aluminum chlorohydrate and tamol can be mentioned, but no restriction on these compounds is provided.

Claims

claims

1. Use of astringent substances as a therapeutically active constituent for the production of a composition for producing light swelling of the skin, the content of astringent substance in the composition being at least 1% by weight.

2. Use according to claim 1 as a sunscreen for human skin.

3. Use according to claim 1 or 2, characterized in that the composition is in the form of solutions, creams, ointments, lotions, sprays, powders or emulsions.

4. Use according to any one of claims 1 to 3, characterized in that the composition contains tannin, tamol, aluminum lactate and / or aluminum chlorohydrate as an astringent substance.

5. Use according to one of the preceding claims, characterized in that the content of astringent substance 2 to 5

% By weight.

6. Use of an astringent substance to make a composition for the artificial thickening of a callus.