JP2012202969A - Skin microrelief evaluation method by measuring contracted state of horny layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To establish an evaluation method capable of evaluating a state of a microrelief more accurately than the conventional texture evaluation method by focusing attention on a skin microrelief structure and the function thereof.SOLUTION: The establishment of the evaluation method is by measuring a contracted state of a horny layer. The horny layer is a component of a microrelief, and it is possible to evaluate a state of the microrelief more accurately by measuring a contracted state of the horny layer.

Description

  The present invention relates to a method for evaluating the microrelief of skin by measuring the contraction state of the stratum corneum. Furthermore, the present invention also relates to a screening method for a skin microrelief improvement candidate drug by measuring the contraction state of the stratum corneum.

  The microrelief composed of skin grooves and cuticles on the skin surface causes light scattering on the skin surface and contributes to the youthfulness and beauty of the skin. In general, the skin of infants has many fine microreliefs that give them a smooth and transparent feeling that is unique to infants. However, with the lapse of age, the microrelief structure disappears and the microrelief structure becomes larger, and the skin groove flows. The directionality causes wrinkles and fine wrinkles. The sensory texture of the skin surface morphology including the microrelief on the skin surface is also called “texture” or “skin texture”. A state in which the microrelief of the skin has deteriorated is expressed as “texture is rough” or “texture is disordered”, especially in cosmetics. Conversely, a state in which the microrelief of the skin is good is expressed as “fine texture” or “texture is in place”.

  Therefore, maintaining the microrelief of the skin is particularly useful in cosmetics, and measuring and evaluating the state of the microrelief is important in cosmetics as well as in research and development of products related to cosmetics and service provision. So far, the method of evaluating the skin condition by photographing the surface of the skin with a microscope and performing information processing on the skin groove and the cuticle (Patent Document 1), and the skin condition using the replica method A method for evaluating skin (Patent Document 2) and a skin texture evaluation method using an acoustic system (Patent Document 3) have been developed.

  However, the texture evaluation methods known so far are based on external measurement of the skin surface condition, and no method for evaluating the texture has yet been developed, focusing on the structure and function of the microrelief. It was.

JP 2006-305184 A JP 2001-170028 JP 2008-114067 A JP 2006-154633 A

T.H.Cook et al .; Journal of the Society of Cosmetic Chemist, 36, 143-152 (published in 1985)

  Therefore, the problem to be solved by the present invention is to establish an evaluation method that enables more accurate evaluation of the texture state than the conventional texture evaluation method by focusing on the structure and function of the microrelief of the skin. That is. Another problem to be solved by the present invention is to provide a screening method for a skin microrelief improvement candidate drug by using an established skin microrelief evaluation method.

  As a result of intensive studies on the relationship between skin extension and texture, the inventors of the present invention opened the microrelief skin groove when the skin extended, thereby causing moderate extension to the skin without causing cracks. New knowledge of giving And based on this finding, as a result of earnest research on the relationship between the microrelief and the surface distance of the skin (the length of the skin surface), surprisingly, as the state of the microrelief of the skin gets worse, It has been found that the skin surface distance tends to be shorter. Based on this discovery, we established a method for evaluating the microrelief state of the skin using as an index the contraction state of the stratum corneum performed for cosmetic purposes.

  Regarding the surface morphology of the microrelief structure on the skin surface, it has been reported that the number of peaks in the crevice / cutaneous skin of the dried skin decreases, but no difference is seen in the average peak size (Non-patent Document). 1). However, no attention has been paid to the surface distance of the skin so far, and it has not been known that the stratum corneum contracts to shorten the surface distance of the skin.

  The present inventors further established a screening method for a skin microrelief improvement candidate drug by using a texture evaluation method on the skin before and after administration of the skin microrelief improvement candidate drug. Specifically, it is a screening method for a skin microrelief improvement candidate drug, the step of measuring the contraction state of the stratum corneum in the skin, the step of administering the skin microrelief improvement candidate drug to the skin, the skin microrelief improvement candidate The process of measuring the contraction state of the stratum corneum at the same or corresponding site after drug administration, and the improvement of the skin microrelief when the contraction state after administration is reduced compared to the contraction state before administration The screening method of the skin microrelief improvement candidate drug which comprises the process that a candidate drug has a skin microrelief improvement effect was established. This screening method includes a step of deteriorating the texture (and skin microrelief) before the step of administering the skin microrelief improvement candidate drug to the skin, and a step of measuring the contraction state of the stratum corneum after the deterioration treatment. Further, it may be included.

  The present inventors further established a screening method for a skin microrelief improvement candidate drug for a skin preparation. That is, a screening method for a skin microrelief improvement candidate drug, a step of measuring a contraction state of a stratum corneum in a skin preparation, a step of subjecting the skin preparation to deterioration treatment, a stratum corneum after deterioration treatment Measuring the contraction state of the skin, the step of administering the skin microrelief improvement candidate drug to the skin preparation, the step of measuring the contraction state of the stratum corneum at the same site after administration of the skin microrelief improvement candidate drug, and When the contraction state after administration of the skin microrelief improvement candidate drug is reduced compared to the contraction state of the stratum corneum after the skin microrelief deterioration treatment step, the skin microrelief improvement candidate drug is A screening method for a skin microrelief improvement candidate drug comprising a step of having a relief improving effect was established.

  More preferably, in the present invention, the contraction state of the stratum corneum can be determined by measuring the skin surface distance / planar distance and the change in the stratum corneum at the same site (corneal layer contraction rate). The skin microrelief evaluation method includes a step of comparing the measured contraction state of the stratum corneum with a reference value of the contraction state of the stratum corneum.

  The contraction state of the stratum corneum can be quantified by measuring the surface distance / planar distance of the skin in a skin replica created by the replica method. Alternatively, the contraction state of the stratum corneum may be measured by taking a skin preparation obtained by the stratum corneum sheet method or the tape stripping stratum corneum under a microscope and overlaying the images, It may be quantified by measuring the surface distance / planar distance of the skin preparation.

  The measurement of the contraction state of the stratum corneum is performed by directly measuring the state of the stratum corneum, which is an important factor constituting the texture and the skin microrelief. Therefore, the skin micro-relief evaluation method of the present application can grasp the structure of the skin micro-relief more accurately and directly than the conventional method of measuring the physical condition, resulting in a clearer understanding of the condition of the texture. It has an advantage in that it can be done. In addition, there is an advantage in providing a multifaceted approach to the skin microrelief evaluation method.

FIG. 1 shows an enlarged view of a skin replica before and after SDS (Sodium dodecyl sulfate) treatment. By the SDS processing, the state of the microrelief of the skin is deteriorated, and the texture is disturbed. FIG. 2 shows a cross-sectional view between the same two points of the skin replica before and after the SDS process. The SDS process slightly increases the planar distance while shortening the surface distance. FIG. 3 shows that the texture deteriorated by the SDS treatment was recovered by the treatment of glycerin or glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (AQ) after the SDS treatment. FIG. 4 is a diagram showing changes in surface distance / planar distance between two points when the treatment of glycerin or glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (AQ) is performed after SDS treatment. It is. It shows that the surface distance / planar distance recovered to the same level as before SDS treatment by the treatment of glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (AQ). FIG. 5 is a graph showing the stratum corneum shrinkage ratio after treatment with glycerin or glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (AQ) after SDS treatment. The treatment of glycerin or glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (AQ) significantly eased the stratum corneum shrinkage due to the SDS treatment. FIG. 6 is a diagram in which the stratum corneum obtained by the tape strip is superimposed with images taken with a fluorescence microscope before and after the SDS treatment and the drying treatment. Images taken before SDS processing and drying processing (upper stage) are shown in green, images taken after SDS processing and drying processing (middle stage) are shown in red, and images obtained by superimposing the images are shown in the lower stage. . A portion where the upper image and the middle image overlap is shown in yellow. Since each of the stratum corneum cells obtained by the tape strip is contracted by the SDS treatment and the drying treatment, a green portion is shown as an edge (indicated by an arrow) in the lower image. The color photograph of FIG. 6 was attached to the application filed on the same date as this application. FIG. 7 is a diagram in which the stratum corneum obtained by the tape strip is superimposed with images taken by a scanning electron microscope before and after the drying process. An image taken before the drying process (upper stage) is shown in green, an image taken after the drying process (middle stage) is shown in red, and an image obtained by superimposing the images is shown in the lower stage. The part where the upper image and the interrupted image overlap is shown in yellow. Since the stratum corneum has shrunk due to the drying process, a green portion is shown as an edge in the lower image (indicated by an arrow). The color photograph in FIG. 7 is attached to the application filed on the same date as this application.

  The present invention relates to a skin microrelief evaluation method using the contraction state of the stratum corneum as an index. By evaluating the skin microrelief state using the contraction state of the stratum corneum as an index before and after the skin microrelief improvement process, the effect of the skin microrelief improvement process can be investigated. By improving the skin micro-relief, it is possible to realize a beautifully beautiful skin with fine texture. Examples of the skin microrelief improving treatment include skin care such as moisturizing, use of skin care products, and massage. However, the skin microrelief improving process is not limited to these as long as it is intended to improve skin microrelief. In addition, it is also possible to evaluate the texture state which is a more sensory texture using the microrelief evaluation method of the present invention.

  The skin microrelief evaluation method of the present invention is performed for cosmetic, diagnostic, or therapeutic purposes. Among them, it is particularly preferable to carry out for cosmetic purposes such as research and development of products related to beauty and service provision. Such a skin microrelief evaluation method performed for cosmetic purposes is performed for non-diagnostic and non-therapeutic purposes, and is performed by a beautician or a general person.

  More preferably, the skin microrelief evaluation method includes a step of comparing the measured contraction state of the stratum corneum with a reference value of the contraction state of the stratum corneum. The reference value can be calculated by measuring the contraction state of the stratum corneum for a specific part, for example, a part such as a cheek, for example, a face or an arm for a group of subjects of various ages. For example, the contraction state of the average stratum corneum at each age can be used as the reference value.

  In another aspect of the present invention, the present invention relates to a screening method for a skin microrelief improvement candidate drug. The screening method includes a step of measuring the contraction state of the stratum corneum at the same or corresponding site before and after administration of the skin microrelief improvement candidate drug. When the contracted state of the stratum corneum after administration is relaxed compared to the contracted state of the stratum corneum before administration, the skin microrelief improvement candidate drug can be evaluated as having a skin microrelief improving effect. it can. Instead of administering the skin microrelief improvement candidate drug, skin microrelief improvement processing can be performed to evaluate whether the skin microrelief improvement processing is effective.

  The screening method for a skin microrelief improvement candidate drug of the present invention preferably includes a step of aggravating the microrelief state (texture condition) by performing a microrelief deterioration process in advance before administration of the skin microrelief improvement candidate drug. . This step facilitates the evaluation of the effect of the skin microrelief improvement candidate drug on the microrelief that has been deteriorated in advance. When the contraction state of the stratum corneum is significantly improved when a skin microrelief improvement candidate drug is administered compared to a control that has been subjected only to the deterioration treatment, the skin microrelief improvement candidate drug has a skin microrelief improvement effect. Can be evaluated. The skin microrelief improvement candidate drug may be administered before the start of the deterioration process, simultaneously with the deterioration process, or after the start of the deterioration process, but is preferably administered after the start of the deterioration process, particularly after the end of the deterioration process. . Instead of administering the skin microrelief improvement candidate drug, it is also possible to evaluate whether the skin microrelief improvement process is effective in improving the skin microrelief by performing a skin microrelief improvement process. Examples of skin microrelief deterioration treatment include surfactants such as SDS, organic solvents such as acetone, application of fatty acid solutions such as oleic acid, administration of pro-inflammatory agents, drying and friction. Although it is mentioned, it is not restricted to these, if the micro relief of a skin and the state of a texture can be deteriorated.

  The contraction state of the stratum corneum can be quantified by measuring the surface distance / planar distance of the skin. When the microrelief state is excellent, the surface distance / planar distance increases because the crevice is deep and increases, but when the microrelief state deteriorates, the surface distance / planar distance decreases. The surface distance / planar distance varies depending on the site of the skin. For example, 1.2 or more, 1.3 or more, 1.4 or more, 1.5 or more, 1.6 or more, 1.7 or more, 1.8 or more. As mentioned above, when it is 1.9 or more, or 2.0 or more, it is judged that the micro relief state is excellent. On the other hand, when it is 1.18 or less, 1.15 or less, 1.12 or less, 1.08 or less, or 1.05 or less, it is determined that the microrelief state is bad.

Further, the stratum corneum contraction rate can be obtained by applying the surface distance before each treatment and the surface distance after the treatment to the following formula. This can be used as an index of the effect of the skin microrelief improvement candidate drug.
Stratum corneum shrinkage (%) = [1− (surface distance after treatment / surface distance before treatment)] × 100
When the stratum corneum contraction rate is 1% or more, preferably 2% or more, particularly 3% or more, 4% or more, or 5% or more, it is judged that the texture state has deteriorated. When the stratum corneum contraction rate is less than 0%, preferably -1% or less, or -2% or less, it is judged that the texture state has improved.

  In another embodiment of the method for screening a skin microrelief improvement candidate drug, the skin microrelief improvement candidate drug is administered to a skin preparation prepared from a mammal. The use of a skin preparation is advantageous in that large-scale screening can be performed. The skin preparation is a preparation obtained by isolating the epidermis of the skin, particularly the stratum corneum, and can be prepared by a method such as a stratum corneum sheet method or a tape stripping stratum corneum method. The contraction state of the stratum corneum for the skin preparation can be measured by photographing the skin preparation using a microscope and overlaying the images. As the microscope, an optical microscope, a scanning electron microscope, or a confocal microscope can be used. To evaluate changes in the contraction state of the stratum corneum for skin preparations, calculate the area of stratum corneum cells in the images before and after processing and based on the area of stratum corneum cells using any image processing software Shrinkage rate can be measured (shrinkage rate based on cell area = (cell area before treatment−cell area after treatment) / cell area before treatment × 100). When the drying process or the SDS process is performed, the shrinkage rate based on the cell area is 5% or more, preferably 10% or more. When the skin improvement candidate drug is administered during the drying process or the SDS process, and the contraction rate is lower than that of the control not administered with the improvement candidate drug, the skin microrelief improvement candidate drug It is shown that it is effective for improvement.

  In the present invention, “microrelief” refers to a three-dimensional physical three-dimensional structure composed of irregularities made up of skin ridges and skin grooves existing on the surface of the skin. On the other hand, the texture in the present application refers to a sensuous texture of the skin composed of the form of the skin surface including the microrelief on the skin surface. The skin part constituting the microrelief is surrounded by a skin groove, and many take a triangular shape, but some take a polygonal shape. A good microrelief is a state where there are a large number of fine triangular cuticles and crevices that are well-shaped, and when the microrelief is good, ”,“ Fine texture ”, or“ Fair texture ”. As the aging progresses, the skin grooves and hills become unclear, the number and density of the skin grooves decrease, and the length of the skin grooves tends to increase. In such a case, the texture that is a sensory texture is evaluated as “bad texture”, “rough texture”, “distorted texture”, or the like. As a result of research on the present invention, it has been found that the microrelief contributes to the flexible extensibility of the skin by opening the skin groove part when the body surface extends. Therefore, microrelief plays an important role in creating rich expressions on the face.

  As a site for measuring the skin microrelief, any site can be used, but preferably a site in a non-movable region can be used. In particular, non-movable regions of the skin of the face such as the cheeks and the forehead, the back of the hand, and the skin of the arms are preferable. Corresponding site skin refers to, for example, the skin on the right cheek relative to the skin on the left cheek, and refers to the skin on the site expected to have substantially the same microrelief state.

  The “replica method” is a method of measuring the skin condition using a skin replica. The skin replica is obtained by applying a replica agent to the skin and separating the replica agent from the skin after drying. See Patent Document 4 for a specific method of manufacturing a skin replica. The replica method is an effective method for expressing the uneven state of the skin, and the uneven state of the skin is extremely important information for beauty and makeup. Photographing the collected skin replicas using a confocal microscope and reconstructing a three-dimensional structure to measure the plane distance between two points and the surface distance (path) between the two points. Can do. By measuring the skin surface distance relative to the planar distance between two points, the contraction state of the stratum corneum can be measured.

  “Surface distance” refers to the total length (distance) of the skin surface between two arbitrarily defined points. On the other hand, “plane distance” refers to a linear distance between two points arbitrarily determined. The surface distance and plane distance between two points determined arbitrarily can be measured, and the surface distance relative to the plane distance (surface distance / plane distance) can be used as an index representing the contraction state of the stratum corneum.

  The “horny layer sheet method” is a method for obtaining a stratum corneum sheet, which is a skin preparation, by treating trypsin, especially the epidermis of skin tissue. The skin tissue can be obtained from any mammal, and in particular, a surplus skin fragment obtained during diet surgery can also be used. The obtained stratum corneum sheet is subjected to various treatments (moisturization, drying, SDS treatment, etc.), and changes in the stratum corneum sheet are measured using a microscope, for example, an optical microscope, a fluorescence microscope, a scanning electron microscope, or the like. Thus, the influence of each process can be examined. More specifically, before and after each treatment, the stratum corneum was stained with fluorescein sodium, and the stratum corneum was photographed using a fluorescence microscope, and the changes in the contracted state caused by the treatment were evaluated by overlaying the images before and after the treatment. can do.

  The “tape stripping stratum corneum method” is a method for obtaining a skin preparation by peeling a stratum corneum using a tape such as a cellophane tape. The stratum corneum is separated from the tape or separated from the tape and subjected to various treatments (moisturization, drying, SDS treatment, etc.), and the stratum corneum is changed using a microscope such as an optical microscope, a fluorescence microscope, a scanning electron microscope, or a confocal microscope. By measuring, the influence of each process can be examined. More specifically, the tape peeling stratum corneum after each treatment is stained with fluorescein sodium, photographed using a fluorescence microscope, and the change in the contracted state caused by the treatment is evaluated by superimposing the images before and after the treatment. be able to. Moreover, the image image | photographed with the confocal microscope, without dyeing | staining a tape peeling stratum corneum as it is, can also be used.

  The term “administration” as used herein includes, but is not limited to, transdermal administration, oral administration, intradermal administration, subcutaneous administration, intramuscular administration, intravenous administration, intraperitoneal administration, and the like. It is not a thing. Preferably, the medicament is administered by transdermal administration, subcutaneous administration, or intradermal administration. More preferably, the drug is administered by occlusive application using a patch test bandage. In yet another embodiment, administration includes application to the collected epidermis sheet or stratum corneum.

Example 1: Measurement of stratum corneum contraction state using replica method As an exacerbation treatment, 400 μl of 5% sodium dodecyl sulfate (SDS) aqueous solution was soaked in a patch test adhesive bandage having a diameter of 2.5 cm. Was placed in contact with the forearm of a healthy male and occluded for 15 minutes. This SDS occlusion application was performed for 3 consecutive days to worsen the texture. A skin replica of the same test site was prepared before SDS treatment (1st day) and the day after the final SDS treatment (4th day from the start date of the test). Skin replicas were made using Silfo (Flexico developments, Potters Bar, UK). The deterioration of the microrelief state was evident from the enlarged image of the skin replica (FIG. 1).

  Next, the three-dimensional morphology of the skin replica was analyzed using a confocal microscope. Two points to be the same point were set on the first day and the fourth day, and a cross-sectional view between the two points was created from the three-dimensional structure of the skin replica (FIG. 2). From this sectional view, the plane distance and the surface distance between the two points were calculated. The planar distance before SDS processing (1492 μm) was little different from the planar distance after SDS processing (1543 μm), but the surface distance before SDS processing (1828 μm) was considerably longer than the surface distance after SDS processing (1718 μm). It was. When the surface distance / planar distance was calculated, it was 1.23 before the SDS treatment, but decreased to 1.11 after the SDS treatment. This value can be used as an index for evaluating the skin microrelief state (FIG. 2).

  In addition, for the purpose of screening a skin microrelief improvement candidate drug, after applying SDS occlusion, the skin microrelief improvement candidate drug was applied three times a day. Here, glycerin, glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether (AQ) was applied to the forearm of 10 healthy men as a known drug for improving the texture after SDS treatment. . As a control, no drug application was performed after SDS treatment. Skin replicas of the same test site were created on the 1st and 4th days before the SDS treatment (1st day) and the day after application of the candidate drug after the SDS treatment (4th day from the start date of the test). Skin replicas were made using Silfo (Flexico developments, Potters Bar, UK). Although the skin microrelief state is worsened by SDS treatment, the skin microrelief state has been recovered by treatment with glycerin, glycerin + polyoxyethylene (14) polyoxypropylene (7) dimethyl ether, which are candidate drugs for improving skin microrelief thereafter. However, it became clear from the enlarged image of the replica (FIG. 3).

  Next, the three-dimensional morphology of the skin replica was analyzed using a confocal microscope. Two points that are the same point are set on the 1st and 4th day, and a cross-sectional view between the two points is created from the three-dimensional structure of the skin replica. From this cross-sectional view, the plane distance and the surface distance between the two points Was calculated respectively. A graph was obtained by calculating the surface distance / planar distance before SDS processing (1st day) and the day after the candidate drug application day (4th day from the start date of the test) (FIG. 4). Further, a value obtained by dividing the surface distance on the fourth day by the surface distance on the first day was subtracted from 1, and the contraction rate of the skin surface was obtained. This was used as an index of the effect of the drug (corneal contraction rate (%) = [1- (surface distance on the fourth day / surface distance on the first day)] × 100, FIG. 5). It is known that glycerin exhibits a moisturizing effect, and polyoxyethylene (14) polyoxypropylene (7) dimethyl ether is a drug having an effect of improving skin microrelief. Therefore, the skin micro-relief improvement candidate having the effect of improving the skin micro-relief by calculating the surface distance / plane distance or using the stratum corneum contraction rate as an index in the screening method of the above-mentioned skin micro-relief improvement candidate drug Drug screening becomes possible.

Example 2: Tape stripping stratum corneum analysis method The stratum corneum on the surface was peeled from the skin of healthy men using cellophane tape. This tape was affixed on a slide glass with a double-sided tape with the peeled surface with the stratum corneum on top. The stratum corneum was stained with a sodium fluorescein aqueous solution (0.1%) and observed with a fluorescence microscope. Thereafter, a 1% SDS aqueous solution was dropped onto the stratum corneum and allowed to stand at room temperature for 5 minutes. This was thoroughly washed with water to remove SDS, dried at room temperature, and observed at the same site with a fluorescence microscope. The size of stratum corneum cells after SDS + drying treatment was compared with that before treatment, and the contraction state was measured (FIG. 6). Each image was taken and the area of an arbitrary cell was measured using image processing software (Winroof (Mitani Corp.). As a result, the contraction rate based on the area of the cell was 10 to 20%.

Example 3: Tape stripping stratum corneum analysis method The stratum corneum on the surface was peeled off from the skin of a healthy male using Post-it (registered trademark) (3M company). The image was transferred to a carbon tape on a scanning electron microscope (SEM) stage and photographed with an SEM. Next, drying treatment was performed (dry treatment, time, etc. clearly), and images were taken again by SEM. The photographed image before drying and the photographed image after drying were superimposed (FIG. 7). As a result of measuring the area of the cells using image processing software (Winroof), the contraction rate based on the area of the cells was about 10%.

Claims (7)

  Skin microrelief evaluation method using the contraction state of the stratum corneum performed for cosmetic purposes as an index.   The evaluation method according to claim 1, wherein the contraction state of the stratum corneum is quantified by measuring the surface distance / planar distance of the skin.   The evaluation method according to claim 2, wherein the skin surface distance / planar distance measurement is performed on a skin replica obtained by using a replica method. A method for screening a skin microrelief improvement candidate drug,
Measuring the contraction state of the stratum corneum in a skin preparation,
A step of subjecting the skin preparation to deterioration treatment, and a step of measuring the contraction state of the stratum corneum after the deterioration treatment, the step of administering the skin microrelief improvement candidate drug to the skin preparation,
Compared to the step of measuring the contraction state of the stratum corneum at the same site after administration of the skin microrelief improvement candidate drug, and the administration of the skin microrelief improvement candidate drug compared to the contraction state of the stratum corneum after the skin deterioration treatment process A screening method for a skin microrelief improvement candidate drug, comprising a step in which the skin microrelief improvement candidate drug has a skin microrelief improvement effect when the subsequent contraction state has decreased.   The screening method according to claim 4, wherein the skin preparation is obtained by a stratum corneum sheet method or a tape stripping stratum corneum method.   The screening method according to claim 4 or 5, wherein the contraction state is measured by acquiring an image of a skin preparation under a microscope, and the comparison is performed by superimposing the acquired images.   The screening method according to any one of claims 4 to 6, wherein the contraction state is calculated by calculating a contraction rate based on a cell area under a microscope.