KR20210091480A - Assessment method of protection efficacy of blue light in cosmetics - Google Patents

Abstract

The present invention relates to a method for evaluating the efficacy of protecting a cosmetic blue light, which comprises the steps of: (a) dividing a part of a skin of a subject to set a plurality of blue light irradiation parts, selecting one of the irradiation parts predicted to be recognized with darkening, as a light intensity median irradiating part, and geometrically determining a light intensity of each of the irradiation parts to obtain a minimal persistent pigment darkening dose (MPPDu) of a product-non-applicable part of the subject; (b) setting the blue light irradiation parts by setting a partition after uniformly applying a product sample to the skin of the subject, and obtaining a minimal persistent pigment darkening dose (MPPDp) of the product-non-applicable part of the subject by selecting a blue light intensity of an expected blue light protecting ability of the product sample as a light intensity median part of the irradiation parts; (c) determining a protection percentage factor of blue light (PPBL_i) of each subject in accordance with an equation 1 (PPBLi=MPPDp/MPPDU); and (d) determining a PPBL of a product in accordance with an equation 2, (PPBL=ΣPPBLi/n). Accordingly, a blue light protection efficacy can be clearly confirmed with an index.

Description

Cosmetic blue light blocking efficacy evaluation method {ASSESSMENT METHOD OF PROTECTION EFFICACY OF BLUE LIGHT IN COSMETICS}

The present invention relates to a method for evaluating the blue light blocking efficacy of cosmetics, and more specifically, the present invention relates to a cosmetic blue light blocking efficacy evaluation method that can check the blue light blocking efficacy of cosmetics by comparing the case where the cosmetic is applied and the case where it is not applied it's about

Blue light refers to light with a short wavelength (400 to 500 nm) among visible light, and refers to light emitted in large quantities from displays of smart devices such as TVs and computers and LED lighting devices.

Recently, controversy has arisen about the harmfulness of blue light.

When exposed to blue light for a long time, retinal ganglion cells lead to apoptosis through mitochondria-dependent apoptosis, oxidative stress, and MAP kinase signaling pathways.

Some argue that the biggest problem with the adverse effects of blue light on the eyes is that it can cause macular degeneration. It is known that macular degeneration occurs because the cells of the macula are subjected to oxidative damage by blue light.

Meanwhile, blue light is suspected of causing pathological skin diseases.

The effects of conventional exposure to light and radiation sources on skin and tissues have been extensively studied. The detrimental effects of skin exposure to ultraviolet (UV) radiation are well known, and active research on the role of ultraviolet radiation in skin-related damage is still ongoing.

In research cases confirming the effect of blue light on skin keratinocytes, it has been reported that it slows the growth rate of keratinocytes or affects differentiation.

Various evaluation methods for functional cosmetics for blocking UV light have been introduced, but no evaluation method for blue light blocking efficacy has been disclosed yet.

Therefore, it is urgent to develop a method for evaluating the blocking efficacy of cosmetics against blue light, which may have a detrimental effect on keratinocytes of the skin.

As a related background art, there is a protective action of lutein against blue light directed to a human skin cell line in Korean Patent Application Laid-Open No. 2017-0132855.

An object of the present invention is to solve the above problems, and to provide a cosmetic blue light blocking efficacy evaluation method that can clearly identify the blue light blocking effect as an index when testing the efficacy of cosmetics by setting the blue light blocking index of the cosmetic.

One aspect of the present invention relates to a method for evaluating cosmetic blue light blocking efficacy. The cosmetic blue light blocking efficacy evaluation method (a) divides a part of the subject's skin to set a plurality of blue light irradiation sites, and selects an irradiation site where blackening is expected to be recognized among the irradiation sites as a light intensity median irradiation site, , obtaining a minimal lasting instantaneous blackening amount (MPPDu) of the subject's product-free area by determining the amount of light in each irradiation site isometrically;

(b) After uniformly applying the product sample to the subject's skin, a section is set to set a plurality of blue light irradiation sites, and the blue light quantity of the product sample's expected blue light blocking ability is selected as the light quantity median value of the irradiation site obtaining a minimal lasting instantaneous blackening amount (MPPDp) of the subject's product application site;

(c) determining each subject's blue light blocking ability index (PPBL _i ; Protection Percentage factor of Blue light) according to Equation 1 below; and

(d) determining the blue light blocking ability index (PPBL) of the product according to Equation 2 below.

[Equation 1]

[Equation 2]

Here, n is the number of subjects sampled, and is 10 or more and 20 or less.

In addition, the subject selects skin types Ⅱ, Ⅲ, and Ⅳ based on Fitzpatrick's skin type classification criteria, but the ITA° value according to Equation 3 below is greater than 55 or 10 or less. It may be decided according to the selection criteria to be excluded.

[Equation 3]

Here, L is the brightness factor and b is the color factor.

In addition, even if the above selection criteria are satisfied, the subject may be dropped out in steps (a) and (b) according to the dropout criteria.

In addition, the limitation of the spectrum of the blue light is to emit blue light having a wavelength in the range of 400 to 500 nm by using a color-selective mirror and a collimating lens, and to remove wavelengths less than 400 nm and more than 500 nm by using a filter. .

In addition, the amount of light may be adjusted so that the amount of light is kept constant during the irradiation time of blue light using a light meter.

In addition, the division of the subject's skin in step (a) sets the irradiation site by attaching an opaque tape having 9 through-holes of 0.8 mm × 0.8 mm in size to the inside of the subject's skin to set the irradiation site, and in step (b) For the skin compartment, an irradiation site can be set by attaching an opaque tape having six through-holes of 0.8 mm × 0.8 mm to the skin of the subject.

In addition, the acquisition of the minimum lasting type instantaneous blackening amount (MPPDu) of the product-free area is determined in the range of the minimum lasting type instantaneous blackening amount data set obtained by determining the light amount of each irradiation site isometrically based on the intermediate value of the blue light amount. can be

In addition, the intermediate value of the amount of blue light may be ^{12 J/cm 2 .}

In addition, to obtain the minimum lasting instantaneous blackening amount (MPPDp) of the product application site, the blue light quantity of the blue light blocking ability expected according to the product sample is selected as the light quantity median area of the irradiation site, and the minimum duration of the non-product application site is selected. The amount of blue light irradiation may be determined in proportion to the light amount of the immediate blackening amount MPPDu.

In addition, the proportionality of the light amount of the minimum lasting type instantaneous blackening amount (MPPDu) of the product non-applied area selects a predicted value for the expected blocking ability of the product sample, and the minimum lasting type immediate blackening amount (MPPDu) of the product non-applied area It may be determined by multiplying the predicted value by .

In addition, the acquisition of the minimum lasting type instantaneous blackening amount (MPPDu) of the non-product application site and the acquisition of the minimum lasting type immediate blackening amount (MPPDp) of the product application site are determined at the same time after 2 to 4 hours after blue light irradiation can be

In addition, if the determination of the blue light blocking ability index (PPBL) falls within the correction factor (C) determined according to Equation 4 below within a 95% confidence interval according to the sample standard deviation, reliability is verified and determined, reliability If the condition is not satisfied, the n value may be increased.

[Equation 4]

Here, C is a correction factor

The present invention provides a new blue light blocking ability index (PPBL) that can numerically and clearly confirm the blue light blocking effect of cosmetics, and in addition to the conventional UV blocking factor (SPF) and UV A blocking factor (PFA), blue light harmful to the stratum corneum of the skin By providing an index that can accurately determine the degree of blocking, product suppliers can check the blue light blocking efficacy of cosmetics more accurately, and also expand the product selection criteria by providing new information on the blue light blocking ability index to product users. have the effect that

In addition, since it is derived through an in vivo experiment, it provides a blue light blocking ability index that the actual user who selected the product can easily agree with, and provides selection conditions and dropout requirements for subjects during the experiment, making it more accurate than the UV blocking index measurement method And you can safely check the blue light blocking ability index.

In addition, in order to derive the blue light blocking ability index (PPBL), the minimum lasting type instantaneous blackening amount (MPPDu) of the non-applied area was introduced as a variable, and the median value of the blue light amount was set in advance. By increasing the accuracy, the blue light blocking ability index can be derived through the process of determining the minimum lasting type instantaneous blackening amount (MPPDp) of product application.

In addition, it is possible to greatly increase the reliability of the cosmetic blue light blocking efficacy evaluation method through the verification process of the blue light blocking ability index (PPBL).

1 shows an evaluation procedure of a cosmetic blue light blocking efficacy evaluation method according to an embodiment of the present invention.
Figure 2 shows a plurality of blue light irradiation sites for obtaining the minimum lasting type instantaneous blackening amount (MPPDu) of the product-free site of the cosmetic blue light blocking efficacy evaluation method according to an embodiment of the present invention.
3 shows a plurality of blue light irradiation sites for obtaining the minimum lasting type instantaneous blackening amount (MPPDp) of the product application site of the cosmetic blue light blocking efficacy evaluation method according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings. However, the following drawings are only provided to help the understanding of the present invention, and the present invention is not limited by the following drawings. In addition, since the shape, size, ratio, angle, number, etc. disclosed in the drawings are exemplary, the present invention is not limited to the illustrated matters.

Like reference numerals refer to like elements throughout. In addition, in describing the present invention, if it is determined that a detailed description of a related known technology may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

When 'including', 'having', 'consisting', etc. mentioned in this specification are used, other parts may be added unless 'only' is used. When a component is expressed in the singular, the case in which the plural is included is included unless otherwise explicitly stated.

In interpreting the components, it is interpreted as including an error range even if there is no separate explicit description.

When the positional relationship of two parts is described as 'on', 'on', 'on', 'next to', etc., unless 'directly' or 'directly' is used, between the two parts One or more other portions may be located.

Positional relationships such as 'upper', 'upper surface', 'lower', and 'lower surface' are only described based on the drawings, and do not represent absolute positional relationships. That is, the positions of 'upper' and 'lower' or 'upper surface' and 'lower surface' may be changed according to the observed position.

Hereinafter, a cosmetic blue light blocking efficacy evaluation method according to an embodiment of the present invention will be described with reference to FIG. 1 .

The cosmetic blue light blocking efficacy evaluation method (a) divides a part of the subject's skin to set a plurality of blue light irradiation sites, and selects an irradiation site where blackening is expected to be recognized among the irradiation sites as a light intensity median irradiation site, , obtaining a minimal lasting instantaneous blackening amount (MPPDu) of the subject's product-free area by determining the amount of light in each irradiation site isometrically;

(b) After uniformly applying the product sample to the subject's skin, a section is set to set a plurality of blue light irradiation sites, and the blue light quantity of the product sample's expected blue light blocking ability is selected as the light quantity median value of the irradiation site obtaining a minimal lasting instantaneous blackening amount (MPPDp) of the subject's product application site;

(c) determining each subject's blue light blocking ability index (PPBL _i ; Protection Percentage factor of Blue light) according to Equation 1 below; and

(d) determining the blue light blocking ability index (PPBL) of the product according to Equation 2 below.

[Equation 1]

[Equation 2]

Here, n is the number of subjects sampled and is 10 or more and 20 or less.

First, a part of the subject's skin is partitioned to set a plurality of blue light irradiation sites, and an irradiation site where blackening is expected to be recognized among the irradiation sites is selected as a light intensity median irradiation site, and the light amount of each irradiation site is set proportionally. It is determined to obtain the minimum lasting type instantaneous blackening amount (MPPDu) of the subject's product-free area (S100).

In one embodiment of the present invention, a plurality of subjects may be selected.

For the selection of the plurality of subjects, skin types Ⅱ, Ⅲ, and Ⅳ are selected based on the obtained Fitzpatrick’s skin type classification criteria, but the value of ITA° according to the following Equation 3 exceeds 55 or It may be determined according to the selection criteria excluding subjects with a age of 10 or less.

In the selection of the subject, types II, III, and IV are selected by dividing the subject's responses according to the Fitzpatrick skin type classification criteria according to a preset questionnaire.

In the II, III, and IV types, skin blackening may be formed with respect to blue light having a wavelength in the range of 400 to 500 nm, and erythema and blackening may be easily recognized.

After selecting skin types Ⅱ, Ⅲ, and Ⅳ based on Fitzpatrick's skin type classification criteria, subjects whose ITA° value according to Equation 3 below exceeds 55 or 10 or less are excluded.

[Equation 3]

Here, L is the brightness factor and b is the color factor.

When the value of ITA° exceeds 55, excessive erythema is formed in the subject according to light irradiation, which is undesirable, and when it is 10 or less, skin blackening progresses excessively and the minimum lasting instantaneous blackening amount (MPPDu) ) and the minimum lasting type instantaneous blackening amount (MPPDp) of the product application site is reduced in accuracy.

On the other hand, even if the above selection criteria are satisfied, the subject may be dropped out in steps (a) and (b) according to the dropout criteria.

In the case of preparing the dropout criteria, it is possible to secure the safety of the subject in the cosmetic blue light blocking efficacy evaluation process.

In one embodiment of the present invention, when the blackening does not progress at all after 2 to 4 hours after the subject is irradiated with blue light to the non-applied part of the product sample, the subject may be dropped out.

Here, the blue light is controlled to be emitted by limiting the spectrum of the blue light.

The limitation of the spectrum of the artificial light source is to emit blue light having a wavelength in the range of 400 to 500 nm using a color-sorting mirror and a collimating lens, and using a filter to remove wavelengths less than 400 nm and more than 500 nm.

In one embodiment of the present invention, the artificial light source should emit blue light, and when the color-selective mirror and the collimating lens are used, the spectrum can be very effectively limited to emit blue light having a wavelength in the range of 400 to 500 nm. .

By using the filter, a light beam having a wavelength outside the set blue light range may be excluded from the irradiation light.

By limiting the spectrum and using a filter, it is possible to accurately form skin blackening according to blue light irradiation.

The amount of light may be adjusted so that the amount of light is kept constant during the irradiation time of blue light using a light quantity meter.

When the amount of blue light is constant using the light quantity meter, the accuracy of determining the minimum lasting type instantaneous blackening amount (MPPDu, MPPDp) can be increased.

In one embodiment of the present invention, in the step (a), an opaque tape having nine through-holes having a size of 0.8 mm × 0.8 mm inside the compartment of the subject's skin in step (a) is attached to the subject's skin to set the irradiation site. .

When the irradiation site is set using an opaque tape having 9 through-holes of the above size, the skin division can be very effectively performed, and a data set according to the amount of light in the irradiation site can be efficiently calculated.

When the irradiated area where the blackening is expected to be recognized is used as the intermediate value of the amount of light, the accuracy of the data set is increased, so the minimum lasting type instantaneous blackening amount (MPPDu) of the product-free area, which varies depending on the subject, can be determined more accurately. .

Specifically, the fifth irradiation site among the nine irradiation sites may be set as the median irradiation site, and the amount of light may be determined geometrically.

The intermediate value of the amount of blue light may be ^{12 J/cm 2 .}

The intermediate value of the amount of blue light can be determined experimentally, but ^{in the case of 12 J/cm 2} , it is very preferable because it is easy to check the formation of blackening according to irradiation with blue light in most subjects, and the amount of light is proportional to 9 irradiation sites It can be determined that the light intensity does not exceed the safety of the subject when irradiating the product, and thereafter, in the process of obtaining the minimum lasting instantaneous blackening amount (MPPDu) of the non-applied area, It is advantageous to select a predictive value.

The light amount of each irradiation site is determined isotropically.

The acquisition of the minimum lasting type instantaneous blackening amount (MPPDu) of the product-free area can be determined in the range of the minimum lasting type immediate blackening amount dataset obtained by determining the light amount of each irradiation site isometrically based on the median value of the blue light light amount. there is.

Only by determining the amount of light in the irradiated area isometrically, it is possible to obtain a data set of the minimum lasting instantaneous blackening amount (MPPDu) of an accurate product-free area.

After uniformly applying the product sample to the subject's skin, a partition is set to set a plurality of blue light irradiation sites, and the blue light quantity of the product sample's expected blue light blocking ability is selected as the light quantity median value of the irradiation site. The minimum lasting type instantaneous blackening amount (MPPDp) of the product application site is obtained (S200).

In one embodiment of the present invention, the skin compartment in step (b) can be set to the irradiation site by attaching an opaque tape having six through-holes having a size of 0.8 mm × 0.8 mm to the subject's skin.

When using the opaque tape with six through-holes, it is very easy to divide the skin, and by irradiating the amount of light proportional to the amount of light in the dataset of the minimum lasting type instantaneous blackening amount (MPPDu) of the non-applied area, the subject's product The minimum lasting type instantaneous blackening amount (MPPDp) of the application site can be obtained.

The minimum lasting type instantaneous blackening amount (MPPDp) of the product application site is obtained by selecting the blue light quantity of the blue light blocking ability expected according to the product sample as the light quantity median area of the irradiation site, and the minimum lasting type immediately at the non-product application site. The amount of blue light irradiation may be determined in proportion to the light amount of the blackening amount MPPDu.

In one embodiment of the present invention, when there are 6 through-holes, the fourth irradiation site is selected as the light quantity median value, and the light quantity and irradiation time proportional to the light quantity of the dataset of the minimum lasting type instantaneous blackening (MPPDu) are set. can

The proportionality of the light amount of the minimum lasting type instantaneous blackening amount (MPPDu) of the product non-applied area selects a predicted value for the expected blocking ability of the product sample, and the minimum lasting type immediate blackening amount (MPPDu) of the product non-applied area is the It can be determined by multiplying the predicted values.

The amount of light irradiated to the irradiated area is finally determined by multiplying the light amount of the minimum lasting instantaneous blackening amount (MPPDu) of the product-free area by the predicted value.

In one embodiment of the present invention, when it is predicted that the blue light blocking ability of the product sample can be reduced by 30% compared to the total blue light, the amount of irradiated light can be determined by multiplying the light amount of the minimum lasting instantaneous blackening amount (MPPDu) by 1.3.

The acquisition of the minimum lasting type instantaneous blackening amount (MPPDu) of the non-product application site and the minimum lasting type immediate darkening amount (MPPDp) of the product application area are determined at the same time interval after 2 to 4 hours after blue light irradiation. can

In the case of determining blackening after the elapse of the time after the light irradiation, it is possible to exclude temporary or inaccurate skin blackening, and at the same time interval as the acquisition time of the minimum lasting type instantaneous blackening (MPPDu) of the product-free area. If the minimum lasting type immediate blackening amount (MPPDp) of the product application site is obtained, the determination of the minimum lasting type immediate blackening amount (MPPDp) for the product sample may be more accurate.

The blue light blocking ability index (PPBLi; Protection Percentage factor of Blue light) of each subject is determined according to Equation 1 below (S300).

[Equation 1]

The blue light blocking ability index (PPBLi) of the subject is defined as a value obtained by dividing the minimum lasting instantaneous blackening amount (MPPDp) of the subject's product application site by the minimum lasting immediate darkening amount (MPPDu) of the subject's non-product application site.

Finally, the blue light blocking ability index (PPBL) of the product is determined according to Equation 2 below (S400).

[Equation 2]

Here, n is the number of subjects sampled, and is 10 or more and 20 or less.

The blue light blocking ability index (PPBL) is defined as the arithmetic average of the blue light blocking ability index (PPBLi) of each subject.

If the number of subject samples is less than 10, there is a fear that the effectiveness of the blue light blocking ability index (PPBL) is reduced, and if it exceeds 20, there may be a problem that the evaluation efficiency is reduced.

On the other hand, if the determination of the blue light blocking ability index (PPBL) falls within the correction factor (C) determined according to Equation 4 below within the 95% confidence interval according to the sample standard deviation, the reliability is verified and the blue light blocking ability index is is determined, and when the reliability condition is not satisfied, the n value may be increased.

[Equation 4]

Here, C is a correction coefficient.

In one embodiment of the present invention, a 95% confidence interval used in biological experiments was secured by setting a correction factor within ±17% of the blue light blocking ability index (PPBL), and the reliability of the blue light blocking ability index was verified.

The reliability can be verified to increase the effectiveness of the blue light blocking ability index (PPBL) with a small population.

Hereinafter, preferred examples are presented to help the understanding of the present invention.

Example

(1) Subject selection

According to the following Table 1. Fitzpatrick's skin type classification criteria table, it was judged as skin type Ⅱ, Ⅲ, Ⅳ through the questionnaire for selection of subjects as healthy men and women aged 18 to 60 years without skin disease, In addition, subjects who met the following selection criteria and met the exclusion criteria were excluded and selected.

Selection Criteria

1) A person who voluntarily agrees to participate in the clinical trial after receiving sufficient explanations from the investigator about the type, method, procedure, and predictable side effects and compensation of the trial

2) A healthy person without acute or chronic physical disease including skin disease

Along with the subject questionnaire, the researcher measures the ITA° (individual typology angle) value that reflects the skin color characteristics of the subject using a colorimeter to determine the skin type in the subject selection process, and determines the subject's final skin type based on this did.

type Explanation MED (mJ/cm ² ) ITA° I It always reddens easily (very badly) and rarely darkens. 2 to 30 > 55° II Easily (severely) reddened and slightly blackened. 25-35 < 41° to 55° Ⅲ Moderately reddish, moderately black. 30-50 < 28° to 41° IV It's not very red, and it turns black easily. 45-60 < 10° to 28° Ⅴ Little reddish, very black. 60~80 < -30° to 10° Ⅵ Not red at all, but very black. 85~200 ≤ -30°

Table 1 shows Fitzpatrick's skin type classification criteria table and ITA° reflecting skin color characteristics.

Subjects who answered the questionnaire and subjects whose ITA° value was greater than 55 or less than 10 were excluded from this experiment, even if the skin type was type II, III, or IV in the questionnaire.

Exclusion Criteria

Through the interview with the subject, those who fell under the following conditions were excluded from the subject.

a. Pregnant or lactating women and women of childbearing potential

b. People with a history of photoallergy or photosensitivity

c. Those who have used steroid-containing skin external agents for more than 1 month for the treatment of skin diseases

d. People with sensitive, sensitive skin

e. Those who have skin abnormalities such as spots, acne, erythema, and capillary dilatation in the area irradiated with light

f. Others who are considered unsuitable for the test in the judgment of the principal investigator

dropout criteria

Even if the subjects met the selection criteria and did not meet the exclusion criteria, the subjects were dropped out in the following cases.

a. When the test subject does not develop blackening after 2 to 4 hours of blue light irradiation on the uncoated area

b. In case an unexpected degree of adverse event occurs at the test site

c. In case the test subject is exposed to excessive UV rays in the test site during the course of the experiment, or the evaluation of the results is impaired due to excessive drinking or smoking

e. When the test subject is unable to proceed with the test due to personal circumstances during the course of the test

f. If the tester determines that it is difficult to continue the test

(2) Test method

1) Test site

The test was conducted on a subject or the like. The test site was selected by avoiding skin damage, excessive hair, or areas with a particular difference in color, and was clean and dry.

2) Test substance application method

Figure 2 shows a plurality of blue light irradiation sites for obtaining the minimum lasting type instantaneous blackening amount (MPPDu) of the product-free site of the cosmetic blue light blocking efficacy evaluation method according to an embodiment of the present invention.

Referring to FIG. 2 , the control sample and test sample application area was 35 cm 2 on the back of the subject except for the spine and applied to the test site in an amount of 2.0 mg/cm 2 (total 70.0 mg). A micropipette was used to apply the correct amount of the sample. The sample was uniformly instilled on the skin surface several times and then uniformly applied using a finger thimble or spatula.

The area of the non-applied blue light irradiation site was 52.5 cm 2 , and nine rectangular irradiation sites having an area of 0.8 cm × 0.8 cm were partitioned.

3 shows a plurality of blue light irradiation sites for obtaining the minimum lasting type instantaneous blackening amount (MPPDp) of the product application site of the cosmetic blue light blocking efficacy evaluation method according to an embodiment of the present invention.

Referring to FIG. 3 , the application area of the product sample was 35 cm 2 , and six square irradiation sites having an area of 0.8 cm × 0.8 cm were partitioned.

3) Blue light irradiation equipment

The equipment has a continuous radiation spectrum similar to sunlight and is equipped with a 1000 watt Xenon arc lamp that does not show a specific peak as a light source, and the blue light irradiated from the lamp is a dichroic mirror. It was released after passing through a collimating lens and a collimating lens. A special filter was also used to remove wavelengths below 400 nm and above 500 nm.

During blue light irradiation, using a light quantity meter (DCS-2, Solar Light, USA) was used to check whether the light quantity measurement value was maintained before and after blue light irradiation.

(3) Test sequence

1) test

The blue light blocking effect of the product sample was measured and verified for 10 subjects.

2) Exam schedule

Each test was carried out for 1 day, followed by the following sequence.

The minimum lasting instantaneous blackening amount (MPPDu) of the subject's non-product application site was measured, and the minimum lasting type immediate blackening amount (MPPDp) of the subject's product application site was measured based on the minimum lasting immediate blackening amount of the product-free area. measured.

3) UV irradiation for measurement of the minimum lasting instantaneous blackening amount (MPPDu) of the product-free area

The average minimum lasting blackening amount was tested by applying 12 J/cm 2 .

The average minimum lasting blackening amount was determined experimentally, and it was determined as the average value of the amount of light that could be judged by recognizing the blackening relatively clearly for the subject.

Apply the average minimum lasting blackening amount to 12 J/cm 2 to position 5 (port 5 in the order of irradiation site) where the minimum lasting instant blackening is expected in the ultraviolet artificial irradiator, and the light intensity is 23.0 mW / It was adjusted to cm 2 .

The irradiation time for each location was calculated and determined, and blue light was irradiated.

The blue light irradiation time was calculated as follows according to Equation 5 below.

[Equation 5]

The amount of light at each irradiation site was adjusted to increase the light amount by about 24% by increasing the light irradiation time at isotropic intervals by about 24%.

All calculated values are rounded to the second decimal place.

Light guide One 2 3 4 5 6 7 8 9 Light intensity (mW/cm2) 23.0 23.0 23.0 23.0 23.0 23.0 23.0 23.0 23.0 Equilibrium (%) 0 0 0 0 0 0 0 0 0 Light quantity (J/㎠) 5.1 6.3 7.8 9.7 12.0 14.9 18.5 22.9 28.4 Equilibrium (%) 24.00 24.00 24.00 24.00 - 24.00 24.00 24.00 24.00 Irradiation Time (Sec) 221 274 339 421 522 647 802 995 1234

Table 2 shows the data set according to the measurement of the minimum lasting type instantaneous blackening amount (MPPDu) of the product-free area.

After the blue light irradiation was finished, two experienced researchers determined the minimum lasting instantaneous blackening amount (MPPDu) of the product-free area under a sufficiently bright light source at a certain time within the range of 2 to 4 hours.

The validity of the measured value was increased by preparing a data set for the minimum lasting instantaneous blackening amount in the product-free area for each subject.

4) UV irradiation to measure the minimum lasting type instantaneous blackening amount (MPPDp) of the product application area

The test site was divided according to FIG. 3, and the product sample was applied in an amount of 2.0 mg/cm 2 (total 70.0 mg) to the test site.

After drying at room temperature for 15 minutes, the subject was irradiated with blue light to take a comfortable position. Subjects were kept stationary while irradiating blue light.

By multiplying the value of the data set of the minimum lasting type immediate blackening amount (MPPDu) of the non-product application site of the subject who has obtained the expected blue light blocking ability of the product sample, the minimum lasting type immediate darkening amount (MPPDp) of the product application site is selected. The blue light irradiation time was determined.

In one embodiment, when the expected blue light blocking ability of the product sample is 30%, the total amount of irradiation 12.0 J/cm 2 × 1.3 = 15.6 J/cm ² was assigned to the 4th port.

location of irradiation site One 2 3 4 5 6 MPPDu(J/cm2) 6.3 7.8 9.7 12.0 14.9 18.5 Ultraviolet artificial irradiator port #4 light quantity (J/㎠) 8.2 10.1 12.6 15.6 19.4 24.1 Irradiation Time (Sec) 356 441 548 678 842 1046

Table 3 shows the blue light irradiation time for selecting the minimum lasting type immediate blackening amount (MPPDp) of the product application site according to the data set of the minimum lasting type immediate darkening amount (MPPDu) of the product non-applied area of the subject.

After the blue light irradiation was finished, the same person made the determination at the same time as the minimum lasting type instantaneous blackening amount (MPPDu) of the non-applied part after a time in the range of 2 to 4 hours had elapsed.

4) Criteria for determining the minimum lasting blackening amount

Judgment Criteria - No special changes can be observed +- Faint blackening that can be recognized with the naked eye occurs in some areas irradiated with blue light + Faint blackening that can be recognized with the naked eye in the area before blue light irradiation ++ Clear blackening that can be recognized with the naked eye in the entire area of blue light irradiation S/E Epidermal damage caused by hypersensitivity to blue light or over-irradiation

Table 4 above shows the criteria for determining the minimum lasting blackening amount.

The minimum amount of blue light irradiated to the area where blackening appeared on the front was adopted as the minimum lasting type immediate blackening amount (MPPDu, MPPDp). The blackening condition is judged by two skilled researchers under a sufficiently bright light source, and if the judgment results of the two people are different, the lowest minimum lasting instantaneous blackening amount is adopted among the judgment results.

(4) Result analysis and reliability verification

1) Calculation of the blue light blocking ability index (PPBL) of the subject

[Equation 1]

Equation 1 above defines the blue light blocking ability index (PPBLi; Protection Percentage factor of Blue light) of each subject.

The blue light blocking ability index of the subject was determined by dividing the minimum lasting instantaneous blackening amount (MPPDu) of the product-applied area by the minimum lasting type immediate blackening amount (MPPDu) of the non-product applied area.

2) Calculation of Blue Light Blocking Ability Index (PPBL)

[Equation 2]

Here, n is the number of subjects sampled, and is 10 or more and 20 or less.

Equation 2 above defines the blue light blocking ability index (PPBL) of the product sample.

The blue light blocking ability index (PPBL) of the product sample was determined as the arithmetic mean value of the blue light blocking ability index (PPBLi) of each subject.

2) Reliability verification of blue light blocking ability index (PPBL) measurement

The 95% confidence interval of the blue light blocking ability index (PPBL), which is an arithmetic mean value obtained through the blue light blocking ability index (PPBLi) of each subject, was made to be within ±17% of the calculated blue light blocking ability index (PPBL) value.

Reliability verification is based on the Regulations on the Review of Functional Cosmetics" 'Method and Standards for Measurement of UV Protection Effect' (Ministry of Food and Drug Safety Notice No. 2019-47) and ISO 24442:2011(E). Cosmetics - Sun protection test methods - In vivo determination of sunscreen UVA protection. 1st ed. It was performed according to the reliability verification of 2011-12-15.

A 95% confidence interval was determined from (PPBL-C) to (PPBL+C).

[Equation 4]

where C is the correction factor.

[Equation 6]

Here, S is the standard deviation, t is the degree of freedom, and n is the number of subjects and is 10 or more and 20 or less.

n 10 11 12 13 14 15 16 17 18 19 20 t-value 2.262 2.228 2.201 2.179 2.160 2.145 2.131 2.120 2.110 2.101 2.093

Table 5 shows the degrees of freedom values according to the number of subjects sampled.

A correction factor was calculated according to the degree of freedom.

In addition, the correction factor C was determined in the section satisfying Equations 4 and 6, and if this condition is not met, the number of samples is increased or the test conditions are reset to calculate the blue light blocking ability index (PPBL) again. The reliability of the blue light blocking ability index measurement was verified by this method.

Up to now, the present invention has been looked at mainly with respect to the embodiments. Those of ordinary skill in the art to which the present invention pertains will understand that the present invention can be implemented in modified forms without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments are to be considered in an illustrative rather than a restrictive sense.

The scope of the present invention is indicated in the claims rather than the foregoing description, and all differences within the scope equivalent thereto should be construed as included in the present invention.

Claims (12)

(a) Partitioning a part of the subject's skin to set a plurality of blue light irradiation sites, selecting an irradiation site where blackening is expected to be recognized among the irradiation sites as a light quantity median irradiation site, and equalizing the light amount of each irradiation site obtaining a minimum lasting instantaneous blackening amount (MPPDu) of the subject's product-free area by determining the amount of blackening;
(b) After uniformly applying the product sample to the subject's skin, a section is set to set a plurality of blue light irradiation sites, and the blue light quantity of the product sample's expected blue light blocking ability is selected as the light quantity median value of the irradiation site obtaining a minimal lasting instantaneous blackening amount (MPPDp) of the subject's product application site;
(c) determining each subject's blue light blocking ability index (PPBL _i ; Protection Percentage factor of Blue light) according to Equation 1 below; and
(d) a cosmetic blue light blocking efficacy evaluation method comprising the step of determining the blue light blocking ability index (PPBL) of the product according to the following Equation 2:
[Equation 1]

[Equation 2]

Here, n is the number of subjects sampled, and is 10 or more and 20 or less.
According to claim 1,
The subject selects skin types Ⅱ, Ⅲ, and Ⅳ based on Fitzpatrick's skin type classification criteria, but excludes subjects whose ITA° value according to Equation 3 below is greater than 55 or less than 10 Cosmetic blue light blocking efficacy evaluation method, characterized in that it is determined according to the selection criteria:
[Equation 3]

Here, L is the brightness factor and b is the color factor.
3. The method of claim 2,
Cosmetic blue light blocking efficacy evaluation method, characterized in that the subject is dropped in steps (a) and (b) according to the dropout criteria even if the above selection criteria are satisfied.
According to claim 1,
The blue light spectrum is limited so that blue light having a wavelength in the range of 400 to 500 nm is emitted using a color-selective mirror and a collimating lens, and wavelengths less than 400 nm and more than 500 nm are removed by using a filter. Evaluation method of cosmetic blue light blocking efficacy.
5. The method of claim 4,
The amount of light is a cosmetic blue light blocking efficacy evaluation method, characterized in that it is adjusted so that the amount of light is kept constant during the irradiation time of blue light using a light meter.
According to claim 1,
In the step (a), the skin compartment of the subject is attached to the subject's skin by attaching an opaque tape having 9 through-holes of 0.8 mm × 0.8 mm in size inside to set the irradiation site, and in step (b) The compartment is a method for evaluating blue light blocking efficacy of cosmetics, characterized in that the irradiation site is set by attaching an opaque tape having six through-holes of 0.8 mm × 0.8 mm to the subject's skin.
According to claim 1,
The acquisition of the minimum lasting type immediate blackening amount (MPPDu) of the product-free area is determined in the range of the minimum lasting type instantaneous blackening amount dataset obtained by determining the light amount of each irradiation site isometrically based on the median value of the blue light light amount. A method for evaluating cosmetic blue light blocking efficacy.
8. The method of claim 7,
The blue light intensity intermediate value is 12 J/cm ² Cosmetic blue light blocking efficacy evaluation method, characterized in that.
According to claim 1,
The minimum lasting type instantaneous blackening amount (MPPDp) of the product application site is obtained by selecting the blue light quantity of the blue light blocking ability expected according to the product sample as the light quantity median area of the irradiation site, and the minimum lasting type immediately at the non-product application site. A cosmetic blue light blocking efficacy evaluation method, characterized in that the amount of blue light irradiation is determined in proportion to the light amount of the blackening amount (MPPDu).
10. The method of claim 9,
The proportionality of the light amount of the minimum lasting type instantaneous blackening amount (MPPDu) of the product non-applied area selects a predicted value for the expected blocking ability of the product sample, and the minimum continuous type immediate blackening amount (MPPDu) of the product non-applied area is Cosmetic blue light blocking efficacy evaluation method, characterized in that determined by multiplying the predicted value.
According to claim 1,
The acquisition of the minimum lasting instantaneous blackening amount (MPPDu) of the non-product application site and the minimum lasting immediate blackening amount (MPPDp) of the product application site are determined at the same time after 2 to 4 hours after blue light irradiation. A method for evaluating cosmetic blue light blocking efficacy.
According to claim 1,
The determination of the blue light blocking ability index (PPBL) is determined by verifying the reliability if it falls within the correction factor (C) determined according to Equation 4 below within the 95% confidence interval according to the sample standard deviation, and the reliability condition is determined. If not satisfied, the cosmetic blue light blocking efficacy evaluation method, characterized in that increasing the n value:
[Equation 4]

Here, C is a correction factor.

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