KR20060109648A - Method for determining an individual's sun protection factor required for protecting skin - Google Patents

Abstract

A method for determining individual sun protection factor required for protecting skin is provided to guide a usage and a selection of an ultraviolet protecting product based on a decided ultraviolet protecting factor. A method for determining individual sun protection factor required for protecting skin includes the steps of: deciding an individual's MED(Minimum Erythemal Dose); estimating an intensity of ultraviolet exposed to the individual; and obtaining a value computed by dividing the estimated intensity of ultraviolet by the decided MED.

Description

Method for determining an individual's sun protection factor required for protecting skin}

1 shows a preferred embodiment of step (a) for determining the minimum erythema amount (MED) of an individual in the method according to the invention.

The present invention relates to a method for determining the sunscreen index required for individual and daily protection of the skin from ultraviolet rays and a method for providing cosmetic information using the same. More specifically, taking into account the skin characteristics of an individual and the environmental characteristics that the individual will be in for the job, it provides a measure of how much UV protection the individual needs for the day and thus provides a suitable sunscreen product. It is about a method.

Ultraviolet rays cause an imbalance and damage of the skin's epidermis and dermis, collagen and elastin, reducing skin elasticity, forming wrinkles, and promoting aging. In addition, melanin pigmentation may be induced on the skin, causing spots, freckles, and the like. Furthermore, it can cause serious diseases such as skin cancer, cataracts and immunodeficiency. In order to prevent the effects of ultraviolet rays, the Korea Meteorological Administration and other Meteorological Administrations are currently predicting the UV index in advance, and each individual also prevents the harmful effects of ultraviolet rays by applying a sunscreen to the skin. The sunscreens on the market vary widely in terms of the sunscreen index (SPF), and users are vaguely buying products without specific criteria for which one to choose.

However, there is a significant difference in the sensitivity of the skin to ultraviolet light for each individual. For example, even when exposed to the same amount of ultraviolet light, some people may not be darkened and become dark red, while others may become almost red and black. This is because the difference is greater when the races are different. In addition, there is a big difference according to age. In addition, even in an individual, the amount of ultraviolet light to be exposed on that day varies significantly depending on where the activity occurs. For example, the amount of ultraviolet light to be exposed is relatively low on days spent indoors almost all day, but the amount of ultraviolet light to be exposed is significantly increased on days of outdoor activities such as ski resorts and the sea. Thus, the UV protection index required for the protection of an individual's skin will vary significantly depending on the inherent characteristics of the individual's skin and the characteristics of the environment in which the individual is to be exposed.

However, until now, it has rarely been proposed to provide the sunscreen index required by an individual on a daily basis, and the sunscreen index required by an individual on a daily basis considering both the inherent characteristics of the individual skin and the environmental characteristics of the individual. Providing it has never been proposed further.

The present invention is to solve the above problems, in consideration of both the intrinsic characteristics of the individual skin and the environmental characteristics that the individual will be located, to determine the sun protection index required for each individual to protect the skin from ultraviolet rays The purpose.

Another object of the present invention is to provide a UV protection index determined as described above to guide the selection and use of UV protection products based on this.

In order to achieve the above object, the method for determining the UV protection index of an individual required for skin protection according to the present invention, the skin of the individual in consideration of the unique skin characteristics of the individual and the environmental factors around the individual A method of determining the sun protection factor (SPF) required to protect from ultraviolet light,

(a) determining the minimum erythema of the individual (MED)

(b) predicting the amount of ultraviolet light the individual will be exposed to; and

(c) obtaining a value obtained by dividing the amount of ultraviolet light predicted in (b) by the MED value of the individual determined in step (a).

In the method according to the present invention, the step (a) is characterized by determining through the questionnaire about the burning tendency and tanning tendency of the skin of the individual.

In the method according to the present invention, the step (a), the state after the skin is exposed to the sun for 30 to 45 minutes without applying the sunscreen in the spring and summer, the viewpoint of the skin burn and the skin In terms of burning, the types of skin are classified into six grades, MED values corresponding to each grade are determined, and a questionnaire determines which of the six grades the individual belongs to, and the MED value of the individual. It is characterized by obtaining.

In the above method of the present invention, the step (a) is classified into a plurality of grades according to the skin color, and each grade constituting the grade according to the skin color is further subdivided into a plurality of grades in terms of skin burn again. And after determining the MED value corresponding to each of the grades, it is characterized in that by obtaining a MED value of the individual by determining which grade of the individual among the grades through a questionnaire.

In the method of the present invention, the step (a) is classified into three grades of white skin, normal skin and black skin according to the skin color, and each grade constituting three grades according to the skin color, The skin is further subdivided into two grades in terms of skin burn, depending on the condition after skin exposure to the sun for 30 minutes to 45 minutes without the application of a sunscreen in summer, and the MED value corresponding to each grade is calculated. After deciding, the questionnaire determines which grade the individual belongs to among the grades through a questionnaire to obtain the MED value of the individual.

In the above method of the present invention, the amount of ultraviolet light in the step (b) is predicted on a daily basis, the UV protection index of the individual required for skin protection is characterized in that determined on a daily basis.

In the above method of the present invention, it is preferable to calculate the amount of ultraviolet light in the unit of day from an ultraviolet index (UV Index).

In the above method of the present invention, the ultraviolet light amount is characterized by predicting the radiation amount of the ultraviolet B region reaching the surface at the midnight time at which the solar altitude is the maximum from the ultraviolet index converted in exponential formula.

In the above-described method of the present invention, the amount of ultraviolet light is estimated by giving weight to the amount of light obtained from the ultraviolet index according to the ultraviolet reflectance of the environment to which the individual will be exposed.

In addition, the method for providing skin beauty information according to the present invention may provide an individual with an ultraviolet ray blocking index of an individual required for skin protection determined according to the method of the present invention, or have an ultraviolet ray blocking index together with the ultraviolet ray blocking index. It is characterized by providing information on the product for blocking.

Hereinafter, the present invention will be described in more detail.

In the present specification, "Sun Protection Factor (SPF)" is an index indicating the blocking effect of a product that blocks UVB. Refers to the minimum erythema obtained using the blocking product.

As used herein, the term “minimum erythemal dose (MED)” means a minimum amount of ultraviolet rays that can show erythema in most of the irradiated areas at 16 to 24 hours after irradiation to human skin.

Ultraviolet rays can be classified into ultraviolet C having a wavelength of 200 to 290 nm, ultraviolet B having a wavelength of 290 to 320 nm, and ultraviolet A having a wavelength of 320 to 400 nm. The UV cut index is the value for UVB among them.

The method according to the invention is to provide a daily required SPF for the individual, taking into account the intrinsic properties of the individual skin and the environmental characteristics to which the individual is exposed. SPF is "MED on application / MED on application", as defined above. The present invention, in the SPF formula as described above, in the non-application MED is determined quickly and simply through a simple questionnaire instead of measuring the actual value. In particular, the MED value is determined at the time of application by dividing the grades according to the criteria suitable for Asian skin and questionnaire to determine which grade the individual belongs to.

In addition, the present invention substitutes the amount of ultraviolet light generated in the environment that the individual is exposed to the MED value in the SPF calculation formula as described above. The amount of ultraviolet light is preferably predicted on a daily basis to provide an individual with a sunscreen index on an individual basis for protecting the skin.

The amount of UV light can be estimated by combining seasonal variables, weather (sunny / cloudy), UV exposure time, and outdoor activities. The amount of light due to seasonal variables or weather (cloudy / cloudy) can be determined using the daily UV index provided by the Korea Meteorological Administration. Currently, the Korean Meteorological Agency, including the Republic of Korea, has provided a daily ultraviolet index to reduce the health hazards caused by ultraviolet rays. The World Health Organization (WHO) has developed and encourages the use of the Global Solar UV index for the UV index, and foreign countries, including the United States and Canada, have borrowed it and announce the risk of UV rays on a daily basis. Doing. The UV index is developed by considering the weather change and the stratospheric ozone change, and using this model, it provides a forecast of the risk of overexposure to the sun and suggests how much attention should be paid to outdoor activities. It is. The WHO's UV index is divided into 10 classes, expressed in numbers from 1 to 11+ (above 11). The UV Index provided by the Korea Meteorological Administration is also classified into 10 grades, from 0 to 10, like the WHO's UV Index. The UV index provided by the Korea Meteorological Administration is the exponential expression of the amount of radiation in the ultraviolet B region reaching the surface at the midnight time with the highest solar altitude. "0" indicates that the risk is very low during overexposure, and "9" or higher means that the risk is very high during overexposure. The UV index provided by the Korea Meteorological Agency is shown in Table 1 below for those with normal skin sensitivity.

9.0 or higher Ultraviolet light intensity is very strong. Erythema after skin exposure within 20 minutes 7.0-8.9 UV intensity is strong. Erythema after skin exposure within 30 minutes 5.0 ~ 6.9 UV intensity usually. Erythema when exposed to skin for about 1 hour 3.0-4.9 Low UV intensity. Erythema when exposed to skin for about 100 minutes 0.0-2.9 UV intensity is very low. Erythema after skin exposure for 2-3 hours

The amount of ultraviolet light can be calculated from the meteorological office provided ultraviolet index. The Korea Meteorological Administration calculates the ultraviolet index according to the following standard formula set by the World Meteorological Organization (WMO).

UV index = UV intensity F (25mW / m ² ) / 25

Therefore, the UV index "1" provided by the Korea Meteorological Administration can calculate the total light quantity from the light intensity of approximately 25mW / m ² (Oh Jae-Ho et al., 34 (1) 1998, UV-B radiation transmission model). UV Index Prediction Study). For example, when the ultraviolet index is "2.0" and the exposure time is 2 hours, the total light amount (mJ / cm ² ) is calculated as 2.0 x 0.0025 x 60 x 60 x 2 = 36 mJ / cm ² . On the other hand, when the ultraviolet index is "8.0" and the exposure time is 4 hours, the total light amount (mJ / cm ² ) is calculated as 8.0 x 0.0025 x 60 x 60 x 4 = 288 mJ / cm ² .

In addition to the ultraviolet index provided by the Korean Meteorological Administration, the ultraviolet index provided by all countries providing the ultraviolet index can also be used in the method according to the present invention. While there may be differences in how the UV indexes are calculated for each country, all UV indexes are based on UV intensity, so you can easily calculate the amount of ultraviolet light from each UV index.

It is preferable to give a weight according to the outdoor activity to the estimated amount of ultraviolet light as described above. Depending on the type of outdoor activity and the location of the outdoor activity, the reflectance of ultraviolet rays varies. For example, as shown in Table 2 below.

Place reflectivity lawn 1 ~ 2% concrete 5-10% Tennis court 4-5% ski resort 80-95% sand 15-20% Sleep 10-100%

If the outdoor activity in the ski area, 95% of each of the above calculated UV light amount 36mJ / cm ² , 288mJ / cm ² for each of the 2 hours and 4 hours of exposure time, respectively, the final total UV The amount of light is determined to be 70.2 mJ / cm ² and 561.6 mJ / cm ² . The weight is preferably determined to be the maximum value in each of the reflectance ranges described in Table 2 above so as to achieve the purpose of protecting the skin from ultraviolet rays.

In the method according to the invention, the individual MED can be determined through a questionnaire for each individual. The exact value of an individual MED can be obtained through actual experiments, but this can take considerable time and money, and most people do not want to experiment because it can cause erythema on the skin. Regarding individual MED decisions through surveys, one can also use Fitzpatrick's optical types that are already in use. Fitzpatrick's phototype consists of a combination of skin burn tendancy and skin tanning tendency when exposed to ultraviolet light in the past, which can approximate the extent of MED. Fitzpatrick's optical types are classified into six types as shown in Table 3 below, and MED values corresponding to each type are shown.

type Explanation MED (mJ / cm ² ) I It always turns red very easily and hardly blacks. Skin peels off easily 2 to 30 Ⅱ Easily reddened and slightly black. Skin peels off 25 to 35 Ⅲ Usually reddened and medium black. 30 to 50 Ⅳ It doesn't get very red and gets black easily. 45 to 60 Ⅴ Little red, and very black. 60 to 80 Ⅵ It doesn't turn red at all and becomes very black. 85 to 200

However, such light type may be difficult to apply to Asian skin. This may be caused by a mismatch between the tendency to burn skin and the tendency to burn skin. In this respect, it is preferable to use a skin type determination method as shown in FIG. 1 shows a preferred embodiment of step (a) for determining the minimum erythema amount (MED) of an individual in the method according to the invention.

Hereinafter, the present invention will be described in more detail with reference to preferred embodiments of the present invention, but the scope of the present invention is not limited thereto.

Example 1

For women in their 30s, who were usually evaluated for white skin, the SPF was calculated for a total of four hours of outdoor activities by the sea. The female MED is white skin by the method shown in FIG. 1, and the skin tanning condition is slightly blackened after the skin is exposed to the sun for 30 to 45 minutes without applying a sunscreen in spring and summer. The MED was set at 30. On the other hand, the day's UV index for outdoor activities by the sea was 6, as confirmed by the Korea Meteorological Agency. In this case, the total amount of light (mJ / cm ² ) is 6 x 0.0025 x 60 x 60 x 4 x 2.0 (beach weight) = 432.0 mJ / cm ² . Dividing this by the individual's MED 30, the minimum required SPF index is 14.4.

This is summarized in Table 4 below.

Item shame Personal MED (mJ / cm ² ) 30 UV index 6 UV intensity corresponding to UV index 1 (mW / m ² ) 0.0025 UV exposure time (hr) 4 Total amount of light (mJ / cm ² ) 216 weight 100%

Experimental Example 1

In order to determine whether the method of FIG. 1 for determining the MED of an individual is sufficiently correlated with the measured MED, the actual MED of the thirties women of Example 1 was first measured. At 20 hours after irradiating the skin with UVB, the minimum amount of ultraviolet light that could show erythema in most of the irradiated areas was measured (according to Korean Food and Drug Administration Notification No. 2001-64). After leaving the woman in a comfortable position, the back of the subject was divided into six parts, and each part was irradiated with UVB using an ultraviolet irradiator (Solar simulator 81293, Oriel Instruments, USA). The amount of UV radiation for each of the six sites was increased proportionally by 25% based on the amount of ultraviolet light in the first section. Eighteen hours after the end of ultraviolet irradiation, the erythema state of the subject was determined. Erythema was allowed to be judged by two experienced inspectors under a light source of 500 lux or more. The minimum amount of UVB light irradiated to the site where erythema appeared on the front surface was the minimum erythema amount of each subject. As a result, the minimum erythema amount was found to be 30.5. This supports the fact that the MED value predicted by the method shown in FIG. 1 correlates well with the measured value.

On the other hand, for a total of 40 subjects, the minimum amount of erythema was measured by the same method as that for the female in their 30s and compared with the minimum amount of erythema predicted by the method according to FIG. 1. After the subjects were placed in a comfortable position, each subject's back was divided into six parts, and each part was irradiated with UVB using an ultraviolet irradiator (Solar simulator 81293, Oriel Instruments, USA). Ultraviolet radiation doses at each of six sites were increased proportionally by 25% based on the amount of ultraviolet light in the first compartment. Eighteen hours after the end of the examination, the erythema state of the subject was determined. Erythema was allowed to be judged by two experienced inspectors under a light source of 500 lux or more. The minimum amount of UVB light irradiated to the site where erythema appeared on the front surface was the minimum erythema amount of each subject. The results are shown in Table 5 below.

No. Actual MED MED Prediction Question Answer Forecast section Gap One 59.5 One 20 39.5 2 74.4 3 40 34.4 3 59.5 2 30 29.5 4 74.4 4 50 24.4 5 74.4 4 50 24.4 6 59.5 3 40 19.5 7 38.1 One 20 18.1 8 38.1 One 20 18.1 9 47.6 2 30 17.6 10 74.4 5 60 14.4 11 59.5 4 50 9.5 12 59.5 4 50 9.5 13 39.3 2 30 9.3 14 49.1 3 40 9.1 15 47.6 3 40 7.6 16 47.6 3 40 7.6 17 47.6 3 40 7.6 18 47.6 3 40 7.6 19 47.6 3 40 7.6 20 47.6 3 40 7.6 21 61.4 5 60 1.4 22 38.1 3 40 1.9 23 38.1 3 40 1.9 24 38.1 3 40 1.9 25 38.1 3 40 1.9 26 38.1 3 40 1.9 27 38.1 3 40 2.4 28 47.6 4 50 2.4 29 47.6 4 50 9.5 30 30.5 3 40 9.5 31 30.5 3 40 9.5 32 30.5 3 40 9.5 33 30.5 3 40 10.5 34 19.5 2 30 11.9 35 38.1 4 50 11.9 36 38.1 4 50 19.5 37 30.5 4 50 21.9 38 38.1 5 60 22.4 39 47.6 6 70 22.4 40 24.4 4 50 25.6 Average 12.6

In the above table, "Gap" is "| measured value-predicted value |", and the difference between the measured value and the calculated value is calculated rather than the correlation analysis due to the questionnaire results in the interval of 10 units. The average Gap value of all 40 patients was about 12.6, which means that there was a difference of 10 from the mean of the measured values. In the MED experiment, the amount of light is divided into approximately 10 mJ / cm ² according to the increase rate of light in the MED experiment.

Experimental Example 2

In order to determine whether the amount of ultraviolet light to be exposed to the individual predicted in step (b) of the method according to the present invention is sufficiently correlated with the measured amount of ultraviolet light, the SPF required for the woman according to Example 1 is determined, and then On the day, the amount of ultraviolet (UVB) light for 4 hours was measured using a UV meter (IL1700 Radiometer, International Lights. Co., USA). As a result, the total amount of ultraviolet light measured was 400 mJ / cm ² . It can be seen that this is very similar to 432 mJ / cm ² which is the value predicted according to step (b) of the method of the present invention.

The present invention considers both the intrinsic properties of an individual's skin and the environmental characteristics that the individual is to face, and determines the UV blocking index required for each individual to protect the skin from ultraviolet rays, thereby providing the individual with the individual. It is effective in protecting skin effectively. In addition, it is possible to effectively guide the selection and use of sunscreen products based on the determined sunscreen index.

Claims (10)

A method of determining the sun protection factor (SPF) required to protect an individual's skin from ultraviolet light, taking into account the individual's unique skin characteristics and the environmental factors surrounding the individual, (a) determining the minimum erythema of the individual (MED) (b) predicting the amount of ultraviolet light the individual will be exposed to; and (c) obtaining a value obtained by dividing the amount of ultraviolet light predicted in (b) by the MED value of the individual determined in step (a). . The method of claim 1, The step (a) is determined by the questionnaire about the burning tendency (burning tendency) and the skin tending (tanning tendancy) of the individual, the method of determining the sun protection index of the individual required for skin protection. The method of claim 2, In step (a), The types of skin are classified into six grades in terms of skin burns and skin burns after the skin is exposed to the sun for 30 to 45 minutes without applying sunscreen in spring and summer. After determining the MED value for each of the above classes, How to determine the UV protection index of the individual required for skin protection, characterized in that to obtain the MED value of the individual by determining which of the six grades the individual through a questionnaire. The method of claim 1, In step (a), Classify according to skin color into multiple grades, Each grade constituting the grade according to the skin color is further subdivided into a plurality of grades in terms of skin burn, After determining the MED value for each of the above classes, Method of determining the sun protection index of the individual required for skin protection, characterized in that to obtain the MED value of the individual by determining which of the classes belonging to the class through a questionnaire. The method of claim 4, wherein In step (a), According to the skin color, it is classified into three grades of white skin, normal skin and black skin. Each grade constituting the three grades according to the skin color, respectively, in terms of skin burning according to the state after the skin is exposed to the sun for 30 to 45 minutes without applying the sunscreen in the spring and summer seasons. Subdivided into ratings, After determining the MED value for each of the above classes, Method of determining the sun protection index of the individual required for skin protection, characterized in that to obtain the MED value of the individual by determining which of the classes belonging to the class through a questionnaire. The method of claim 1, The amount of ultraviolet light in step (b) is predicted on a daily basis, and the method of determining the UV protection index of an individual required for skin protection, characterized in that the UV protection index of the individual required for skin protection is determined on a daily basis. . The method of claim 6, The method for determining the UV protection index of the individual required for skin protection, characterized in that the amount of ultraviolet light in the unit of the day is calculated from the UV Index. The method of claim 7, wherein The UV light amount is determined by the UV index in terms of the exponential expression of the radiation amount of the ultraviolet B region reaching the surface at the midnight time at the highest solar altitude, the method of determining the UV protection index of the individual required for skin protection. The method of claim 7, wherein The ultraviolet light amount is determined by giving a weight according to the ultraviolet light reflectance of the environment to which the individual will be exposed to the amount of light obtained from the ultraviolet index to determine the UV protection index of the individual required for skin protection. Providing the sun protection index of an individual necessary for protecting the skin determined according to any one of claims 1 to 9, or providing information on a sunscreen product having the sun protection index together with the sun protection index. Skin beauty information providing method characterized in that.

Images