JPH05248945A - Evaluation method for ultraviolet ray penetrated preventive effect using animal skin exfoliation film - Google Patents

Abstract

PURPOSE:To evaluate ultraviolet ray transmission preventive effect of a specimen such as an anti-suntan cream without use of any vital organism by applying the specimen to the surface of an animal skin exfoliated film having ultraviolet transmissivity, irradiating it with an artificial light beam from one side, and measuring the dosage of ultraviolet rays transmitted. CONSTITUTION:A specimen 2 is applied to the surface of a hairless molmot skin 1, which is adhere4 to a rectangular holder 3 having a square aperture, and the holder 3 is held vertically by a stand. The irradiation part 41 of a solar simulator 40 is attached to the specimen side of the skin 1 while the light-receiving part 51 of an ultraviolet ray intensity meter 50 is attached to the other side, and the intensity E of the ultraviolet ray penetrating the specimen 2 and skin 1 is measured. Alike the intensity E0 of the ultraviolet rays is measured by using the skin 1 which is free from application of specimen 2, and E/E0 is used as the ultraviolet ray transmission prevention value. Accordingly the ultraviolet ray transmission preventive effect can quickly be evaluated without use of any vital organism.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for evaluating the effect of preventing ultraviolet ray transmission of sunscreen products and the like.

[0002]

2. Description of the Related Art The sun protection factor (Sun Protection Factor) is used as an index showing the effect of so-called sunscreen products such as sunscreens for preventing skin damage caused by sunlight.
protection factor: Sunscreen index, hereinafter referred to as SPF. ) Is widely adopted. In addition, the SPF value is also an important standard in product development and examination.

As a method for measuring SPF, the method specified by the US FDA has been adopted for a long time in Europe and the United States, and a unified measuring method has been proposed in Japan as well, but in all cases, a sunscreen is applied to human skin. Apply and irradiate with ultraviolet rays,
It is represented by the ratio of the amount of irradiation energy (time) that causes the same skin inflammation as when the sunscreen is not used.

[0004]

Since these methods are actually applied to human skin and are excellent as methods for measuring the effects, they differ in the measuring method and conditions under the unified standard in each country. In addition, the SPF value obtained by these methods does not always match the actual UV blocking effect. Further, there is a problem that the measurement takes time and cost, and further, the subject is distressed.

On the other hand, as an alternative to the SPF measuring method, there is a method of using a Hartley type hairy guinea pig.
It cannot be directly compared with the F value, and cannot replace the SPF method that has been adopted for many years. An object of the present invention is to provide an SPF alternative measurement method that can be rapidly measured without using a living body and can be compared with a conventional SPF value.

[0006]

As a result of intensive studies to solve the above problems, the present inventor has found that the above problems can be solved by using an animal skin peeling film, resulting in the present invention. ..

That is, according to the present invention, a sample such as a sunscreen is applied to the surface of an animal skin peeling film, artificial light is irradiated from one surface of the film, and the energy amount of ultraviolet rays passing through the sample and the film is measured. Is a method of evaluating the ultraviolet ray transmission preventing effect of the sample.

The present invention will be described in detail below. First, the method for measuring the amount of energy of the animal skin peeling film, artificial light and ultraviolet rays used in the method of the present invention will be described. The sample referred to in the present invention is a sample such as a sunscreen cosmetic that is applied to the skin and has an ultraviolet ray transmission preventing effect (including an ultraviolet ray scattering effect).

If the animal skin peeling membrane used in the present invention does not transmit ultraviolet rays, it is impossible to measure the amount of ultraviolet rays passing through the sample. Therefore, it is preferable to use an epidermis which itself transmits ultraviolet rays. .. In particular, the skin of hairless animals such as hairless guinea pigs and hairless mice is preferable.

As a method of obtaining the epidermis, there is a method of treating the peeled skin with an enzyme that decomposes the tissue between the epidermis and the dermis. This enzyme is preferably a proteolytic enzyme used for animal tissue culture.

The artificial ray used in the present invention may be any ray containing ultraviolet rays, and examples of the light source include a xenon arc lamp (2500, 1000, 150 watts), a high pressure halogen lamp, an intermediate pressure mercury lamp and the like. It is preferable to use these as a light source and to use them as parallel rays. The ultraviolet energy is measured using an ultraviolet intensity meter. The light receiving part of the ultraviolet intensity meter has a smaller area than the artificial skin material.

Next, a method for evaluating the effect of preventing ultraviolet ray transmission of the sample to be measured using the above-mentioned animal skin peeling film, artificial light source, and ultraviolet intensity meter will be described.

A sample to be measured is applied to one surface of the animal skin peeling film, preferably to the skin surface side. This film may be supported on a flat surface using a frame or the like. The irradiation section of the artificial light source and the light receiving section of the ultraviolet intensity meter are opposed to each other so as to sandwich this film. Both the light receiving unit and the irradiation unit are installed separately from the film. At this time, the ultraviolet light emitted from the irradiation unit is adjusted so that the light reception unit is vertically irradiated, and the energy amount received by the light reception unit is always maximized with the film removed. It is preferable to set the position.

An artificial ray is radiated from the side of the film coated with the sample so as to pass through the sample, and the energy amount (E) of the ultraviolet rays passing through the sample and the film is measured. Similarly, the amount of energy of ultraviolet rays (E
₀ ) is measured and the ultraviolet ray transmission prevention value is calculated by the following formula.

UV transmission preventing value = E ₀ / E

When a comparison with the SPF value by the conventional method is required, it can be obtained from a standard straight line prepared using a standard sample.

[0017]

EXAMPLES Examples of the present invention and a comparison with SPF values by the FDA method will be described below.

<1> Measuring Method of Example A measuring method of this example will be described with reference to FIG. As the animal skin peeling film, a hairless guinea pig skin epidermis was used.
Phosphate buffered saline containing 1000 PU / ml of skinless tissue of hairless guinea pig, fat and muscle under the subdermis removed with tweezers, and dispase (Proteolytic enzyme manufactured by Godo Shusei Co., Ltd .: Bacillus polymixa) at 1000 PU / ml. And was treated at 37 ° C. for 2-3 hours. The epidermis thus obtained can be stored at 50% RH.

The artificial light source was a Model 14S solar simulator manufactured by Solar Light Co., and the UV intensity meter was a UVR-305 / 365D (III) UV radiometer manufactured by Topcon. The wavelength of the irradiated ultraviolet rays was 290 to 400 nm (UVB + UVA region), the ultraviolet intensity was 7 mW / cm ² , and the irradiation time was 5 minutes.

Sample 2 was applied to the surface side of the hairless guinea pig epidermis 1 at a dose of 2 mg / cm ^2, and this film was 7.6 cm having a square window of 2 cm × 2 cm.
Adhere to the window hole of the rectangular holder 3 of × 3.6 cm,
The holder was held vertically by a stand. In addition, what adhere | attached the skin to the holder may be preserve | saved and a sample may be apply | coated to this.

The irradiation part 41 of the solar simulator 40 is applied to the sample surface of the epidermis, and the light receiving part 51 of the ultraviolet intensity meter 50 is applied to the other surface to measure the ultraviolet intensity E (mW / cm ² ) which passes through the sample and the epidermis. did. On the other hand, the ultraviolet intensity E ₀ ) was similarly measured using a film on which the sample was not applied, and E ₀ / E was taken as the ultraviolet transmission preventing value.

<2> Sample used for evaluation of ultraviolet ray transmission preventing effect As the sample, a simple formulation in which a base material is mixed with an ultraviolet absorber and a cosmetic in which the ultraviolet absorber is mixed are used.

(1) Sample of Simple Formulation An ultraviolet absorber and petrolatum were mixed in the ratio shown in Table 1 to prepare 60
A sample was obtained by heating to 0 ° C., stirring and mixing to dissolve homogeneously, and then cooling to room temperature. Hereinafter, these are referred to as Samples 1 to 4.

[0024]

[Table 1]

(2) Cosmetic containing UV absorber (Emulsion 1) The ingredients shown in Tables 2A and 2B are heated to 70 ° C.,
Mixed and dissolved. While stirring the mixed solution of A, the mixed solution of B was added to this and emulsified, and then cooled to 30 ° C. to obtain an emulsion.

[0026]

[Table 2]

(Emulsion 2) The ingredients of Tables 3A and 3B were each 70 ° C.
It was heated to and mixed and dissolved. While stirring the mixed solution of A,
To this, the mixed solution of B was added to emulsify, and the mixture was cooled to 40 ° C., then the fragrance was added and stirred, and further cooled to 30 ° C. to obtain an emulsion.

[0028]

[Table 3]

(Emulsion 3) Each of the components shown in Tables 4A and 4B is 70
The mixture was heated to ℃ and mixed and dissolved. While stirring the mixed solution of A, the mixed solution of B was added to this and emulsified, and then cooled to 30 ° C. to obtain an emulsion.

[0030]

[Table 4]

(Emulsion 4) Each of the ingredients shown in Tables 5A and 5B is 70
The mixture was heated to ℃ and mixed and dissolved. While stirring the mixed solution of A, the mixed solution of B was added to this and emulsified, and then cooled to 30 ° C. to obtain an emulsion.

[0032]

[Table 5]

(Emulsions 5 and 6) The components shown in Tables 6A and 6B were heated to 70 ° C. and mixed and dissolved. While stirring the mixed solution of A, the mixed solution of B was added to this and emulsified, and then cooled to 30 ° C. to obtain an emulsion.

[0034]

[Table 6]

<3> FDA Method 20 or more test subjects (O / W type emulsion (SPF = 4.0) containing 8% homosalate (3,3,5-trimethylcyclohexyl salicylate) as standard) 50c on the back of skin type I, II, or III)
The sample is applied to a portion of m ² or more at a rate of 2 mg / cm ² or 2 μl / cm ² , and the solar simulator is used to increase the dose at the minimum dose x (1.25 ⁿ ) when the sample is not applied. After 24 hours, the minimum erythema dose MED (minimum energy amount or irradiation time that produces a slight erythema visible to the naked eye) was measured and calculated by the following formula.

SPF = (ME on skin using cosmetics
D) / (MED on skin without cosmetics)

<4> Comparison of UV Transmission Prevention Value by the Method of the Present Invention and SPF Value by the FDA Method Below, the UV transmission prevention value measured by the method of the present invention and the SPF value measured by the FDA method for the above samples are shown. Shows a comparison with.

(1) Comparison of Samples with Simple Formulation The results of Samples 1 to 4 are shown in Table 7 and FIG.

[0039]

[Table 7]

(2) Comparison of emulsions containing UV absorbers Table 8 shows the results of emulsions 1-6.

[0041]

[Table 8]

A commercially available program (“Organization of experimental data”, manufactured by Baifukan Co., Ltd.) was used to calculate the linear regression line and the correlation coefficient from the measured values by computer processing. As a result, the correlation coefficient was 0.98 (risk rate <0.001).

(3) Evaluation From the above results, it is clear that the ultraviolet ray transmission prevention value measured by the method of the present invention over a wide range is proportional to the SPF value. Furthermore, it was found that this proportional relationship was not affected by the composition of the sample.

[0044]

According to the present invention, the effect of preventing the penetration of ultraviolet rays such as sunscreen can be easily and quickly evaluated without using a living body. Further, the UV transmission preventing value measured according to the present invention has a proportional relationship with the conventionally measured SPF value, and thus can be used as an alternative measuring method of the SPF value. Moreover, the use of a uniform animal skin peeling membrane can give reproducible results.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing an example of a method of the present invention.

FIG. 2 is a diagram showing a relationship between an ultraviolet ray transmission prevention value and an SPF value in a sample having a simple formulation.

FIG. 3 is a diagram showing a linear regression line of an ultraviolet ray transmission prevention value and an SPF value in emulsions having different compositions.

[Explanation of symbols] 1. Animal skin exfoliation membrane 2. Sample 3. Holder 40. Artificial light source 41. Irradiation unit 50. Ultraviolet intensity meter 51. Light receiving section

Claims (2)

[Claims] 1. A sample such as a sunscreen is applied to the surface of a UV-permeable animal skin peeling film, and artificial light is irradiated from one surface of this film to determine the amount of energy of ultraviolet light that passes through the sample and the film. A method for evaluating the ultraviolet ray transmission preventing effect of the sample by measuring. 2. A method for evaluating the effect of preventing ultraviolet light transmission, wherein the animal skin peeling film is a hairless animal skin peeling film.