Method for evaluating emulsified compositions, apparatus for evaluating emulsified compositions, program for evaluating emulsified compositions, system for evaluating emulsified compositions, and method for designing emulsified cosmetics.

Abstract

To provide a novel technology for evaluating the state of a coating film of an emulsifying composition when it comes into contact with a liquid such as water. [Solution] An evaluation method for an emulsified composition, comprising an evaluation step of evaluating the properties of the coated film of the emulsified composition based on a cross-sectional image in the depth direction of the skin obtained while the coated film of the emulsified composition formed on the skin is in contact with a liquid.

Description

Technical Field

[0001] The present invention relates to a method for evaluating an emulsion composition, an evaluation apparatus, an evaluation program, an evaluation system, and a method for designing an emulsion cosmetic.

Background Art

[0002] Conventionally, in order to evaluate the state of a cosmetic or the like applied to the skin, a technique has been developed for evaluating the adhesion state of a cosmetic film after application of the cosmetic using a tomographic image obtained by optical coherence tomography (OCT). Patent Document 1 discloses a method for evaluating a cosmetic skin, which uses low coherence light in a plurality of visible regions having different wavelengths, compares the OCT images of each wavelength obtained thereby, and evaluates the adhesion state of the cosmetic film and the optical properties inside the cosmetic skin.

[0003] By the way, among cosmetics, especially sunscreen cosmetics, which are emulsion compositions, are required to have a persistence that does not come off even in sweat or water, and the persistence of their effects has been evaluated by conventional evaluations on a substrate, observations using replicas, and in vivo water resistance tests.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] As described above, the conventional evaluation of the water resistance of sunscreen cosmetics does not observe the state of the emulsion composition film, but focuses on the film properties and cannot evaluate the water resistance of the cosmetics based on these properties.

[0006] In view of the above, the object of the present invention is to provide a novel technique for evaluating the state of a coating film of an emulsifying composition when it comes into contact with a liquid such as water. [Means for solving the problem]

[0007] The inventors of this invention diligently conducted research seeking a method that could objectively evaluate the resistance of an emulsified composition to contact liquids such as water, and furthermore, to evaluate its resistance to sweat secreted from the body, and have completed the present invention. The present invention and its preferred embodiments for solving the above problems are as follows.

[0008] [1] A method for evaluating an emulsified composition, comprising an evaluation step of evaluating the properties of a coated film of the emulsified composition based on a cross-sectional image of the depth direction of the skin obtained when the coated film of the emulsified composition formed on the skin is in contact with a liquid. By using cross-sectional images of the skin in the depth direction, the properties of the coated film of an emulsified composition in contact with a liquid can be easily evaluated.

[0009] [2] A contact step of bringing the coated film of the emulsified composition into contact with the liquid, The process includes an evaluation image acquisition step in which a cross-sectional image of the skin in the depth direction is acquired while the coated film is in contact with the liquid, The method for evaluating an emulsified composition according to [1], wherein the characteristics of the coated film of the emulsified composition are evaluated based on the cross-sectional image obtained in the evaluation image acquisition step.

[0010] [3] The cross-sectional image of the skin in the depth direction is obtained with the liquid droplets standing still on the coating film, the method for evaluating the emulsified composition according to [1] or [2]. This configuration allows for easy evaluation of changes in the state of the coated film of the emulsified composition due to contact with an external liquid.

[0011] [4] The method for evaluating an emulsified composition according to [1] or [2], wherein the cross-sectional image of the skin in the depth direction is obtained when the liquid generated from the skin is in contact with the coating film. This configuration allows for easy evaluation of changes in the state of the coated film of the emulsified composition due to liquids such as sweat secreted from the body.

[0012] [5] A method for evaluating an emulsified composition according to any one of [1] to [4], wherein the liquid is sweat. This configuration allows for the evaluation of the coated film of the emulsified composition under conditions close to those in which the emulsified composition is actually used.

[0013] [6] The evaluation step comprises calculating a characteristic quantity indicating a change in the state of the coating film of the emulsified composition, and evaluating the properties of the coating film of the emulsified composition using the characteristic quantity as an indicator, as described in any one of [1] to [5]. This configuration allows for objective evaluation of the properties of the coated film of the emulsified composition.

[0014] [7] The characteristic of the coating film of the emulsified composition is the adhesion of the coating film of the emulsified composition, The method for evaluating an emulsified composition according to [6], wherein the aforementioned feature quantities are feature quantities relating to the lifting of the applied film of the emulsified composition from the skin and / or feature quantities relating to exposed skin. This configuration allows for a simple and objective evaluation of changes in the adhesion of the coating film when it comes into contact with a liquid.

[0015] [8] The method for evaluating an emulsified composition according to any one of [1] to [7], wherein the cross-sectional image is an optical coherence tomography image. Optical coherence tomography (OCT) allows for easy acquisition of cross-sectional images of the skin in the depth direction.

[0016] [9] The optical coherence tomography image is obtained using infrared light, the method for evaluating the emulsified composition according to [8]. By using infrared light, it is possible to obtain a cross-sectional image in the depth direction of the skin, in which the state of the coating film of the emulsified composition can be clearly confirmed even when the coating film of the emulsified composition is in contact with a liquid.

[0017]

[10] An evaluation apparatus for an emulsified composition, comprising an evaluation unit that evaluates the characteristics of the coating film of the emulsified composition based on a cross-sectional image in the depth direction of the skin obtained in a state where the coating film of the emulsified composition formed on the skin is in contact with a liquid.

[0018]

[11] An evaluation program for an emulsified composition, which causes a computer to function as an evaluation unit that evaluates the characteristics of the coating film of the emulsified composition based on a cross-sectional image in the depth direction of the skin obtained in a state where the coating film of the emulsified composition formed on the skin is in contact with a liquid.

[0019]

[12] A cross-sectional image acquisition unit that acquires a cross-sectional image in the depth direction of the skin on which a coating film of an emulsified composition is formed, and an evaluation unit that evaluates the characteristics of the coating film of the emulsified composition based on the cross-sectional image acquired by the cross-sectional image acquisition unit, and the cross-sectional image acquisition unit acquires the cross-sectional image in a state where the coating film is in contact with a liquid, an evaluation system for an emulsified composition.

[0020]

[13] An evaluation step of evaluating the characteristics of the coating film of the emulsified composition based on a cross-sectional image in the depth direction of the skin obtained in a state where a coating film formed on the skin with an emulsified composition prepared using an emulsifier for a subject is in contact with a liquid, and a selection step of selecting, as an emulsifier to be blended in a cosmetic, an emulsifier for which the evaluation of the characteristics of the coating film in the evaluation step was suitable, and A method for designing an emulsified cosmetic, comprising. According to the present invention, an emulsified cosmetic can be designed based on the characteristics of the coating film of the emulsified composition.

Effects of the Invention

[0021] According to the present invention, a novel technique is available that allows for the evaluation of the state of the coating film of an emulsifying composition when it comes into contact with a liquid. [Brief explanation of the drawing]

[0022] [Figure 1] This flowchart shows a specific embodiment of the method for evaluating the emulsified composition of the present invention. [Figure 2] This is a functional block diagram of the evaluation apparatus 10 for the emulsified composition of the present invention. [Figure 3] This is a functional block diagram of the evaluation system 1 for the emulsified composition of the present invention. [Figure 4] This is an optical coherence tomography image showing the state of change in the coating film of the emulsified composition due to the application of artificial sweat from an external source in Test Example 1. [Figure 5] This is an optical coherence tomography image showing the state of change in the coated film of the emulsifying composition due to internal sweating in Test Example 1. [Figure 6] This is an optical coherence tomography image showing an example of calculating the retention rate of the coated film of the emulsified composition in Test Example 2. [Modes for carrying out the invention]

[0023] The present invention relates to a technique for evaluating the properties of a coating film of an emulsified composition. One embodiment of the present invention is described below. However, the present invention is not limited to the embodiments described below and can be modified as appropriate within the scope of the invention.

[0024] <1> Evaluation method for emulsified compositions The method for evaluating an emulsified composition of the present invention (hereinafter also referred to as the evaluation method of the present invention) comprises an application step S1 of applying the emulsified composition to be evaluated onto the skin, a contact step S2 of bringing the applied film of the emulsified composition formed on the skin into contact with a liquid, an evaluation image acquisition step S3 of acquiring a cross-sectional image in the depth direction of the skin, and an evaluation step S4 of evaluating the properties of the applied film of the emulsified composition based on the obtained cross-sectional image (Figure 1).

[0025] The evaluation method of the present invention may perform all of the above steps, or it may perform only a part of the above steps. For example, it may perform only evaluation step S4 based on a cross-sectional image of the skin obtained in the depth direction in advance.

[0026] The following provides a detailed explanation of each step.

[0027] (1) Coating process S1 Application step S1 is the step of applying the emulsified composition to the skin.

[0028] The skin to which the emulsified composition is applied is not particularly limited as long as it has properties similar to skin, and skin substitutes such as human skin or human leather can be used.

[0029] When using human skin, the area to which the emulsified composition is applied is not particularly limited. For example, the back of the hand, arm, foot, etc., can be selected as appropriate.

[0030] The emulsifying composition used is not particularly limited and may be any of O / W type emulsion, W / O type emulsion, W / O / W type emulsion, or O / W / O type emulsion. This invention evaluates the properties of an emulsified composition when it comes into contact with a liquid, and is particularly suitable for evaluating its resistance to liquids such as water, and is therefore especially suitable for evaluating O / W type emulsions.

[0031] Furthermore, preferred examples of emulsifying compositions to be used include cosmetics, pharmaceuticals, quasi-drugs, etc. The emulsifying composition may also be a wound dressing composition.

[0032] In the coating step S1, it is preferable to allow the emulsion composition to dry for a certain period of time after application and before performing the subsequent contact step S2. By drying the emulsion composition, a coating film of the emulsion composition can be formed on the skin, allowing for proper evaluation in the evaluation step S4.

[0033] (2) Contact process S2 Contact step S2 is a step in which the coated film of the emulsified composition is brought into contact with the liquid. The liquid that comes into contact with the coating film of the emulsified composition is not particularly limited, and water such as tap water or purified water, extracorporeal secretions, or imitations thereof can be used.

[0034] In the present invention, the liquid that comes into contact with the coating film of the emulsified composition is preferably an extracorporeal secretion, and more preferably sweat. In the present invention, artificial sweat can be used as an imitation of an extracorporeal secretion. By adopting this form, especially when the emulsified composition is a sunscreen cosmetic, it is possible to evaluate the emulsified composition under conditions that are close to those under which the emulsified composition is actually used.

[0035] In one embodiment, the contact step S2 includes the step of placing a droplet on the coated film. This configuration allows for easy evaluation of changes in the state of the coated film of the emulsified composition due to contact with an external liquid.

[0036] In other embodiments, the contact step S2 includes bringing a liquid generated from the skin into contact with a coated film of the emulsifying composition. The fluid generated from the skin can preferably be an extracorporeal secretion or an imitation thereof. Examples of extracorporeal secretions include sweat, sebum, other secretions, and mixtures thereof. This configuration allows for easy evaluation of changes in the state of the coated film of the emulsified composition due to external secretions such as sweat secreted from within the body.

[0037] In this embodiment, the liquid generated from the skin is more preferably one or more of sweat, sebum, and mixtures thereof.

[0038] The step of bringing the applied film into contact with sweat generated from the skin preferably includes performing an action that promotes sweating. Such actions that promote sweating are preferably exercise and / or actions in a high-temperature environment.

[0039] When exercising to promote sweating, it is preferable to engage in moderate to high intensity exercise, such as walking, running, or cycling. Furthermore, suitable examples of activities in high-temperature environments include activities in constant-temperature rooms, saunas, and outdoors during the summer (for example, outdoors at temperatures above 30°C).

[0040] (3) Evaluation image acquisition process S3 The evaluation image acquisition step S3 is a step in which a cross-sectional image of the skin in the depth direction (hereinafter also simply referred to as a cross-sectional image) is acquired while the coated film of the emulsified composition is in contact with the liquid.

[0041] When a droplet is placed on the coating film during the contact step S2, it is preferable that the cross-sectional image be taken while the droplet is placed on the coating film.

[0042] In the contact step S2, when the liquid generated from the skin is brought into contact with the coating film of the emulsifying composition, it is preferable that the cross-sectional image be taken while the liquid generated from the skin is in contact with the coating film. Furthermore, in this embodiment, it is preferable that the cross-sectional image is obtained when the sweat generated from the skin by performing an action that promotes sweating is in contact with the coated film of the emulsified composition. This configuration makes it possible to evaluate the properties of the coated film of the emulsified composition under conditions of vigorous sweat secretion. A preferred example of an action that promotes sweating is as described in the contact step S2 above.

[0043] In a configuration where a liquid generated from the skin is brought into contact with a coating film of the emulsified composition, it is preferable that the cross-sectional image be obtained with the sweat pores and sweat glands of the skin in an expanded state. This configuration allows for the evaluation of the properties of the coated film of the emulsified composition under conditions of high sweat secretion.

[0044] The cross-sectional images to be acquired can be obtained using optical coherence tomography (OCT). OCT imaging devices can acquire tomographic images at a depth of several millimeters from the epidermis of living organisms. In other words, in the present invention, it is preferable to acquire optical coherence tomography images as cross-sectional images.

[0045] Optical coherence tomography (OCT) images obtained by OCT (hereinafter also referred to as OCT images) are preferably obtained by irradiating with infrared light. Infrared light includes near-infrared light, mid-infrared light, and far-infrared light, ranging from those close to visible light. In this invention, the infrared light irradiated may be any of near-infrared light, mid-infrared light, or far-infrared light. By using the above-mentioned light, it is possible to obtain a cross-sectional image in the depth direction of the skin in which the state of the coating film of the emulsified composition can be clearly confirmed, even when the coating film is in contact with the liquid.

[0046] In this invention, it is preferable that the OCT image is obtained by irradiating with light of a wavelength of 680 to 1500 nm.

[0047] More specifically, the wavelength of the infrared light to be irradiated is preferably 790 nm or more, more preferably 800 nm or more, more preferably 830 nm or more, and even more preferably 850 nm or more. The wavelength of the infrared light to be irradiated may also be 900 nm or more, 950 nm or more, 1000 nm or more, 1100 nm or more, 1200 nm or more, or 1300 nm or more. The wavelength of the infrared light to be irradiated is preferably 2000 nm or less, more preferably 1800 nm or less, more preferably 1500 nm or less, and even more preferably 1400 nm or less. The wavelength of the infrared light to be irradiated is preferably 790 to 2000 nm, more preferably 800 to 1500 nm, even more preferably 830 to 1500 nm, and still more preferably 850 to 1400 nm. The wavelength of the infrared light to be irradiated may also be 900 to 2000 nm, 950 to 1800 nm, 1000 to 1500 nm, 1100 to 1500 nm, 1200 to 1500 nm, or 1300 to 1400 nm.

[0048] The wavelength range can preferably be ±50 to 200 nm around the central wavelength, ±100 to 180 nm around the central wavelength, or ±150 to 180 nm around the central wavelength.

[0049] In one embodiment, light with a central wavelength of 850 nm and a wavelength width of 165 nm can be irradiated. Alternatively, light with a central wavelength of 1310 nm and a wavelength width of 170 nm can also be irradiated.

[0050] By using light of the above wavelengths, it is possible to obtain a cross-sectional image in the depth direction of the skin, which clearly shows the state of the coating film of the emulsified composition, even when the coating film is in contact with the liquid. Furthermore, this configuration also allows for clear confirmation of the boundary between the skin and the coating film.

[0051] Furthermore, it is preferable that the light used to acquire OCT images be low-coherence light.

[0052] Existing OCT imaging devices can be used to acquire OCT images; for example, SS-OCT (IVS-2000-ST, manufactured by Santec Corporation) can be used.

[0053] In the evaluation image acquisition step S3, in order to evaluate the changes in the coating film, it is also preferable to acquire cross-sectional images obtained after the coating step S1 but before the coating film comes into contact with the liquid, in addition to cross-sectional images obtained when the coating film of the emulsified composition is in contact with the liquid. This configuration allows for evaluation of changes in the coated film before and after contact with the liquid.

[0054] (4) Evaluation process S4 Evaluation step S4 is a step in which the properties of the emulsion coating film formed on the skin are evaluated based on a cross-sectional image of the skin in the depth direction obtained while the coating film of the emulsion composition formed on the skin is in contact with a liquid. Preferably, the cross-sectional image is obtained in the evaluation image acquisition step S3.

[0055] The properties of the coated film of the emulsified composition are preferably evaluated by comparing an OCT image taken before the coated film of the emulsified composition formed on the skin comes into contact with a liquid, with an OCT image taken after the coated film comes into contact with the liquid. In one embodiment, it is preferable to evaluate the properties of the coating film of the emulsified composition by calculating a characteristic quantity that indicates the change in the state of the coating film of the emulsified composition when it comes into contact with a liquid (hereinafter referred to as a characteristic quantity related to the change in the coating film), and using this characteristic quantity as an indicator. This configuration allows for objective evaluation of the properties of the coated film of the emulsified composition.

[0056] Examples of characteristic quantities related to changes in the coated film include characteristics related to the lifting of the coated film, characteristics related to exposed skin, characteristics related to the degree of turbidity of the liquid in contact with the coated film, and characteristics related to cracks that have formed in the coated film. In the present invention, one or more of these characteristic quantities can be used.

[0057] The properties of the coating film of the emulsified composition to be evaluated in evaluation step S4 include, but are not limited to, the adhesion of the coating film, the resistance of the coating film to liquids, and the durability of the coating film. In the present invention, one or more of these properties of the coating film of the emulsified composition can be selected and evaluated.

[0058] In one embodiment, it is preferable to evaluate the adhesion of the coating film of the emulsified composition as a characteristic of the coating film of the emulsified composition in evaluation step S4.

[0059] When evaluating the adhesion of an emulsified composition coating film, it is preferable that in evaluation step S4, the characteristic quantity relating to the change in the coating film is a characteristic quantity relating to the lifting of the emulsified composition coating film from the skin, and / or a characteristic quantity relating to exposed skin. This configuration allows for a simple and objective evaluation of changes in the adhesion of the coating film when it comes into contact with a liquid.

[0060] In evaluating the lifting of the coating film, it is preferable to acquire, in the evaluation image acquisition step S3, a cross-sectional image (initial image) after the coating step S1 and before the liquid comes into contact with the coating film, and a cross-sectional image (evaluation image) after a certain period of time has elapsed after the liquid has come into contact with the coating film. In evaluation step S4, the adhesion of the emulsion composition coating can be evaluated by calculating the remaining percentage of the coating film adhered to the skin (coating film retention rate) using the obtained initial image and evaluation image.

[0061] The retention rate of the coating film can be calculated using the following formula 1. (Equation 1) Retention rate of the coating film (%) = (Length of the coating film adhered to the skin calculated from the evaluation image / Length of the coating film adhered to the skin calculated from the initial image) × 100

[0062] In evaluation step S4, a higher retention rate of the coating film indicates higher adhesion of the emulsion composition to the coating film. This evaluation is preferably applicable when comparing two or more emulsion compositions.

[0063] In evaluation step S4, a standard value for the retention rate of the coated film may be set, and if the retention rate is higher than the standard value, the adhesion of the emulsified composition may be evaluated as high.

[0064] When using features related to exposed skin as an indicator, these features can be obtained by acquiring initial and evaluation images using the same procedure as the method for calculating the retention rate of the coating film described above, and then calculating the "length of skin exposed after the coating film has peeled off" instead of the "length of the coating film adhered to the skin".

[0065] In other words, by using the obtained initial image and evaluation image, the adhesion of the emulsion composition coating can be evaluated by calculating the percentage of skin exposed due to peeling of the coating film. The percentage of exposed skin can be calculated using the following formula 2. (Equation 2) Percentage of exposed skin (%) = (Length of exposed skin surface calculated from evaluation image / Length of exposed skin surface calculated from initial image) × 100 Furthermore, it is preferable that the length of the exposed skin surface be the length of the skin surface portion (the upper boundary line of the skin) that is not in contact with the coated film, as seen in the cross-sectional image of the skin in the depth direction.

[0066] In evaluation step S4, a lower percentage of exposed skin indicates higher adhesion of the emulsion composition coating. This evaluation is preferably applicable when comparing two or more emulsion compositions.

[0067] In evaluation step S4, a standard value for the percentage of exposed skin may be set, and if the value of the percentage of exposed skin is lower than the standard value, the adhesion of the emulsified composition may be evaluated as high.

[0068] Furthermore, in one embodiment, in evaluation step S4, the resistance of the coating film of the emulsified composition to liquids can be evaluated as a characteristic of the coating film of the emulsified composition. In a preferred embodiment, the resistance of the coating film of the emulsified composition to liquids can be evaluated against one or more selected from extracorporeal secretions, specifically sweat, sebum, and mixtures thereof. In the present invention, it is more preferable to evaluate the resistance of the coating film of the emulsified composition to sweat.

[0069] When evaluating the resistance of an emulsified composition coating film to liquid, it is preferable that the characteristic quantities relating to changes in the coating film are characteristic quantities relating to cracks that have formed in the coating film and / or characteristic quantities relating to exposed skin. This configuration allows for a simple and objective evaluation of the coating's resistance to bodily secretions such as sweat.

[0070] As characteristic quantities related to cracks occurring in the coating film, one or more selected from the number of cracks and the size of the cracks are preferably exemplified. The size of a crack can be determined by measuring the width of the crack in a cross-sectional image. If multiple cracks are present, the average and / or maximum crack size can be used for evaluation.

[0071] When the number of cracks in the coating film is used as a characteristic quantity, the fewer the number of cracks, the more resistant the coating film of the emulsion composition is to liquids. When the size of cracks in the coating film is used as a characteristic quantity, the smaller the average and / or maximum value of the cracks, the more resistant the coating film of the emulsion composition is to liquids. Such an evaluation is preferably applicable when comparing and evaluating two or more emulsified compositions.

[0072] In evaluation step S4, a standard value may be set for the number and / or size of cracks in the coating film, and if the number and / or size of the cracks are less than the standard value, the coating film of the emulsified composition may be evaluated as having resistance to liquid.

[0073] When evaluating the resistance of an emulsified composition coating film to liquids, if a feature quantity related to exposed skin is used, it is preferable to calculate a feature quantity related to the size of the skin exposed due to cracking. Features related to the size of exposed skin include the total length of the exposed skin surface in the cross-sectional image (i.e., the total width of the cracks if multiple cracks are present).

[0074] In evaluation step S4, the percentage of exposed skin can be calculated and evaluated, similar to the evaluation of the adhesion of the emulsion coating film described above. In this configuration, the lower the percentage of exposed skin, the more resistant the emulsion coating film is to liquids. This evaluation is preferably applicable when two or more emulsion compositions are compared and evaluated.

[0075] In evaluation step S4, a standard value for the percentage of exposed skin may be set, and if the value of the percentage of exposed skin is lower than the standard value, the coating film of the emulsified composition may be evaluated as having resistance to liquid.

[0076] Furthermore, when evaluating the durability of a coating film of an emulsified composition, the durability can be evaluated based on the time-dependent changes in the values ​​of the characteristic quantities related to the changes in the coating film described above. In one embodiment, a reference value can be set for the characteristic quantity related to the change in the coating film, and the durability of the coating film of the emulsified composition can be evaluated based on the time required to exceed or fall below the reference value. In another embodiment, the durability of the coating film of the emulsified composition can be evaluated based on the value of the characteristic quantity related to the change in the coating film after a predetermined time has elapsed.

[0077] Specifically, an example of this method involves using cross-sectional images taken after a predetermined period of time to calculate the retention rate of the emulsion coating film using the procedure described above, and evaluating that the emulsion coating film has durability if the value of the retention rate exceeds a standard value.

[0078] As described above, the evaluation method of the present invention allows for the simple evaluation of the properties of the coated film of an emulsified composition when it comes into contact with a liquid such as sweat, using cross-sectional images of the depth direction of the skin.

[0079] Furthermore, the evaluation method of the present invention may include a acclimatization step to acclimate the skin before applying the emulsified composition to the skin. In the acclimatization process, the skin is cleansed using a cleansing agent or facial wash and allowed to acclimate for a predetermined time. The acclimatization time is not particularly limited, but it is preferably about 10 minutes. The acclimatization process is preferably carried out when using living skin.

[0080] Furthermore, if the present invention includes an evaluation step S4, the evaluation method may be configured such that a computer performs the evaluation step S4.

[0081] The evaluation apparatus, evaluation program, evaluation system, and design method for the emulsified composition of the present invention will be described below. <1> This is for implementing the evaluation method for emulsified compositions described in the section above. Furthermore, in the design method for emulsified cosmetics of the present invention, the evaluation form of the emulsified composition is as described above. <1> This evaluation method will be applied. Therefore, the above <1> The descriptions in this section also apply to the evaluation apparatus, evaluation program, evaluation system, and design method for emulsified cosmetic products described below.

[0082] <2> Evaluation apparatus for emulsified compositions The evaluation apparatus for the emulsified composition of the present invention will be described below with reference to Figure 2. Figure 2 shows the functional configuration of the emulsified composition evaluation apparatus 10 (hereinafter simply referred to as the evaluation apparatus 10). The evaluation apparatus 10 can be a general-purpose computer device equipped with computing units such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit), main memory such as RAM (Random Access Memory), auxiliary storage such as an HDD (Hard Disk Drive), an SSD (Solid State Drive), or flash memory, and various input / output devices including means for connecting to a network. It is also possible to configure the evaluation apparatus 10 using multiple computers.

[0083] In this embodiment, "part" may also include, for example, hardware resources implemented by circuits in a broad sense, and the software information processing that can be specifically realized by these hardware resources.

[0084] The evaluation device 10 includes an image data acquisition unit 101 that acquires image data to be evaluated, a storage unit 102 that stores a program or model for evaluating the properties of the coating film of the emulsified composition, an evaluation unit 103 that evaluates the properties of the coating film, and an output unit 104 that outputs the evaluation results.

[0085] The image data acquisition unit 101 acquires cross-sectional image data of the skin in the depth direction obtained when the coated film of the emulsified composition formed on the skin is in contact with the liquid.

[0086] In this embodiment, the imaging device that acquires cross-sectional images in the depth direction of the skin can be configured to transmit the image data directly to the image data acquisition unit 101 via wired or wireless connection. Alternatively, the image data acquisition unit 101 may acquire the cross-sectional images acquired by the imaging device via a network.

[0087] The storage unit 102 is an HDD, SSD, flash memory, RAM, etc., and stores a program or model for evaluating the properties of the coating film of the emulsified composition, as well as various data. The program or model for evaluating the coating film of the emulsified composition is as described above. <1> This is a program or model for carrying out evaluation process S4 as described in the item.

[0088] The evaluation unit 103 applies a program or model stored in the memory unit 102 for evaluating the emulsion coating film to a cross-sectional image of the skin in the depth direction obtained when the emulsion coating film formed on the skin is in contact with a liquid, and evaluates the properties of the emulsion coating film.

[0089] The evaluation unit 103 may perform image processing for evaluation on the cross-sectional image data acquired by the image data acquisition unit 101.

[0090] The output unit 104 outputs the evaluation results received from the evaluation unit 103 to a display device (not shown), such as a display.

[0091] Although Figure 2 illustrates a configuration that includes the image data acquisition unit 101, storage unit 102, evaluation unit 103, and output unit 104, the present invention is not limited to this configuration. In other words, the evaluation apparatus 10 of the present invention may be configured to include an evaluation unit 103 that evaluates the properties of the emulsion coating film based on a cross-sectional image in the depth direction of the skin obtained while the emulsion coating film formed on the skin is in contact with a liquid.

[0092] The following provides further details about the hardware configuration of the evaluation device 10. The evaluation device 10 comprises a control unit, a storage unit 102, and a communication unit as its hardware configuration. The control unit consists of one or more processors such as a CPU and a GPU, and controls the overall processing in the evaluation device 10 by executing programs or models for evaluating the coated film of the emulsified composition, an OS (Operating System), and other applications. The communication unit controls communication with the communication network and the imaging device, and includes an image data acquisition unit 101 that primarily acquires cross-sectional images used for evaluation.

[0093] <3> Emulsified composition evaluation program The evaluation program for the emulsified composition of the present invention (hereinafter also referred to as the evaluation program of the present invention) is configured to function as an image data acquisition unit 101 that acquires image data to be evaluated, a storage unit 102 that stores a program or model for evaluating the properties of the coating film of the emulsified composition, an evaluation unit 103 that evaluates the properties of the coating film, and an output unit 104 that outputs the evaluation results.

[0094] The evaluation program of the present invention, <2> This corresponds to the functional components of the evaluation device described in the section. Therefore, <2> The description in the section above applies to the evaluation program of this invention.

[0095] Furthermore, the evaluation program of the present invention may also be an evaluation program for an emulsified composition that causes a computer to function as an evaluation unit 103 that evaluates the properties of the coated film of the emulsified composition based on a cross-sectional image in the depth direction of the skin obtained when the coated film of the emulsified composition formed on the skin is in contact with a liquid.

[0096] <4> Evaluation system for emulsified compositions The evaluation system for the emulsified composition of the present invention (hereinafter also referred to as the evaluation system of the present invention) will be described below with reference to Figure 3. The emulsified composition evaluation system 1 (hereinafter referred to as "evaluation system 1") comprises a cross-sectional image acquisition unit 201 that acquires a cross-sectional image in the depth direction of the skin on which a coating film of the emulsified composition is formed, and an evaluation unit 103 that evaluates the properties of the coating film of the emulsified composition based on the cross-sectional image acquired by the cross-sectional image acquisition unit 201.

[0097] In this embodiment, the evaluation system 1 includes an imaging device 20 equipped with a cross-sectional image acquisition unit 201 and an evaluation device 10 equipped with an evaluation unit 103.

[0098] The imaging device 20 is preferably an OCT image acquisition device such as an optical tomography (OCT) scanner. Existing OCT imaging devices can be used, such as SS-OCT (IVS-2000-ST, manufactured by Santec).

[0099] The cross-sectional image acquisition unit 201 of the imaging device 20 acquires a cross-sectional image in the depth direction of the skin while the coated film of the emulsified composition is in contact with the liquid. A preferred form of the method for acquiring the cross-sectional image is: <1> The description in evaluation process S4 for this item can be used as a reference.

[0100] The evaluation device 10 is <2> The evaluation apparatus 10 for emulsified compositions described in the section is preferred.

[0101] The imaging device 20 and the evaluation device 10 may communicate wirelessly or via wired connections, or they may be connected via a network.

[0102] The cross-sectional image of the skin in the depth direction, acquired by the cross-sectional image acquisition unit 201, is output from the communication unit 202 of the imaging device 20. The evaluation device 10 receives the cross-sectional image from the image data acquisition unit 101, and the evaluation unit 103 uses the cross-sectional image to evaluate the properties of the coated film of the emulsified composition.

[0103] Although an example was given in which the imaging device 20 and the evaluation device 10 are different devices, the evaluation system of the present invention may be configured in which the imaging device 20 and the evaluation device 10 are the same device. That is, in the evaluation system of the present invention, the cross-sectional image acquisition unit 201 and the evaluation unit 103 may be configured in the same device or in different devices.

[0104] <5> Design method for emulsified cosmetics The present invention's method for designing emulsified cosmetics (hereinafter also referred to as the "design method of the present invention") includes an evaluation step of evaluating the properties of a coated film of an emulsified composition prepared using an emulsifier under test, and a selection step of selecting an emulsifier to be incorporated into the cosmetic based on the evaluation in the evaluation step.

[0105] The evaluation process involves evaluating the properties of the emulsion coating film, which is formed on the skin using an emulsion composition prepared with the emulsifier under test, based on cross-sectional images of the skin in the depth direction obtained while the coating film is in contact with a liquid. A preferred embodiment of the evaluation process is the above <1> The evaluation process for this item is the same as described in S4.

[0106] The selection step involves selecting an emulsifier that was suitable for evaluating the properties of the coated film of the emulsified composition as an emulsifier to be incorporated into the cosmetic.

[0107] The evaluation of the properties of the coating film of the emulsified composition is considered favorable if, specifically, the coating film of the emulsified composition has high adhesion, is resistant to liquids, and / or is judged to have durability. Of these evaluations, it is sufficient if one or more are favorable, preferably two or more, and even more preferably three or more.

[0108] The design method of the present invention makes it possible to easily select an emulsifier suitable for producing cosmetics that have resistance to liquids in the coated film of the emulsified composition.

[0109] The design method of the present invention can be used for the design of emulsified cosmetics, and preferably for the evaluation of O / W type emulsions. Furthermore, the design method of the present invention can be used not only for cosmetics but also for the design of pharmaceuticals and quasi-drugs. [Examples]

[0110] The present invention will be described in more detail below based on examples, but the present invention is not limited thereto.

[0111] <Test Example 1> Using cross-sectional images of the skin acquired with an OCT scanner, the changes in the state of the sunscreen coating film upon contact with liquid were observed according to the following procedure.

[0112] (1) Apply sunscreen cosmetics The outer forearm was cleansed with a cleanser or face wash and left to stand for 10 minutes to allow it to acclimate. Then, 0.2 mg / cm³ was applied to the outer forearm. 2 Sunscreen cosmetics (Sample 1: O / W type, Sample 2: W / O type) were applied in the following manner. After application, the surface was allowed to dry for 10 minutes, and the state of the sunscreen film was photographed and observed using the OCT device described below.

[0113] [OCT device] ·SS-OCT (IVS-2000‐ST), manufactured by santec ·Field of view: 5mm x 5mm ·Center wavelength: 1310nm, wavelength: 170nm

[0114] (2) Application of sweat to the coated film (2-1) Evaluation of the effects of artificial sweat from external sources After applying and drying the sunscreen cosmetic, apply 0.5 mg / cm² to the application area. 2 Artificial sweat solution (manufactured by Hayashi Pure Chemical Industries, Ltd.) was applied, and the condition of the applied film was photographed and observed using the above-mentioned OCT device immediately after application (0 minutes), and at 3 minutes, 5 minutes, and 10 minutes later.

[0115] (2-2) Evaluation of the effects of internal sweating After applying sunscreen cosmetics and allowing them to dry, participants performed exercise to induce sweating (a 20-minute run outdoors at 35±2℃). The condition of the applied film was photographed and observed immediately after the exercise, and 3 and 10 minutes after the exercise.

[0116] (3) Results (3-1) Changes in the coating film due to the application of artificial sweat from the outside As shown in Figure 4, in the case of Sample 1 (O / W type), swelling of the coating film was observed immediately after application of the artificial sweat solution, and after 3 minutes, the coating film began to dissolve and disperse into the artificial sweat solution. Furthermore, after 5 minutes, the coating film began to detach from the skin, and after 10 minutes, it had completely detached from the skin, with most of the coating film dispersed into the artificial sweat solution. On the other hand, in the case of Sample 2 (W / O type), the coated film repelled the artificial sweat solution, did not swell, and did not detach from the skin, remaining unchanged from its initial state.

[0117] (3-2) Changes in the coating film due to internal sweating As shown in Figure 5, in the case of Sample 1 (O / W type), it was observed that sweat droplets passed through the swollen coating film as sweat was secreted, and after 3 minutes, the sweat that had passed through the coating film was visible on the film surface. After further time had passed, and 10 minutes later when the coating film had dried, cracks were observed in the coating film in the areas where the sweat droplets had passed. On the other hand, in the case of Sample 2 (W / O type), the coating film did not swell, and it was observed that sweat seeped out onto the film surface through gaps in the coating film. Unlike Sample 1 (O / W type), the coating film after drying maintained a uniform coating.

[0118] As described above, it can be seen that changes in the coating film of an emulsified composition when it comes into contact with external water or when it perspires from within can be easily evaluated using OCT images.

[0119] <Test Example 2> We investigated a method for evaluating sunscreen cosmetics using cross-sectional images of the skin taken with an OCT device. Specifically, we evaluated the adhesion of two types of sunscreen cosmetics (oil-in-water emulsions) using the following procedure.

[0120] I washed the back of my hand with a cleanser or face wash and left it to stand for 10 minutes to allow it to acclimate. Next, 0.2 mg / cm³ was applied to a 3 cm x 3 cm area of ​​skin on the back of the hand. 2 0.018g of sunscreen cosmetic was applied to the area. After application, it was allowed to dry for 5 minutes. The dried state was then photographed using an OCT device under the same conditions as in Test Example 1 above. The obtained OCT image was used as the initial image.

[0121] Next, 1-2 drops (0.02g) of water were placed on the coated film formed on the skin. Immediately after placing the water droplets, OCT images were acquired in the same measurement range as the initial image.

[0122] OCT images were continuously acquired under the same conditions for the same measurement range until 15 minutes after placing a water droplet. The OCT image taken at 10 minutes was used as the evaluation image.

[0123] The length of the coating film adhering to the skin was calculated using the initial image. Similarly, the length of the coating film adhering to the skin was calculated for the evaluation image. The length of the coating film adhering to the skin was calculated using image editing software.

[0124] Next, the retention rate of the coating film of the emulsified composition was calculated based on the following formula. Coating retention rate (%) = (Length of coating adhered to skin calculated from evaluation image / Length of coating adhered to skin calculated from initial image) × 100

[0125] Figure 6 shows OCT images of an emulsified composition with a coating retention rate of 95% (a) and an emulsified composition with a coating retention rate of 37% (b). For convenience, Figure 6 shows the areas where the skin and coating are in close contact in the initial image (dotted lines) and the areas where the skin and coating are in close contact in the evaluation image (solid lines) on the evaluation image. As shown in Figure 6, the adhesion of an emulsified composition in contact with a liquid such as water can be easily evaluated using OCT images. [Industrial applicability]

[0126] This invention can be applied to the design, manufacture, and other aspects of emulsified compositions. [Explanation of Symbols]

[0127] 1. Evaluation System 10 Evaluation device 101 Image data acquisition unit 102 Storage section 103 Evaluation Department 104 Output section 20 Imaging device 201 Cross-sectional image acquisition unit 202 Communications Department

Claims

1. A method for evaluating an emulsified composition, comprising an evaluation step of evaluating the properties of a coated film of the emulsified composition based on a cross-sectional image of the skin in the depth direction obtained while the coated film of the emulsified composition formed on the skin is in contact with a liquid.

2. A contact step of bringing the coated film of the emulsifying composition into contact with the liquid, The process includes an evaluation image acquisition step in which a cross-sectional image of the skin in the depth direction is acquired while the coated film is in contact with the liquid, The method for evaluating an emulsified composition according to claim 1, wherein in the evaluation step, the properties of the coated film of the emulsified composition are evaluated based on the cross-sectional image obtained in the evaluation image acquisition step.

3. The method for evaluating an emulsified composition according to claim 1, wherein the cross-sectional image of the skin in the depth direction is obtained with the liquid droplets stationary on the coated film.

4. The method for evaluating an emulsified composition according to claim 1, wherein the cross-sectional image of the skin in the depth direction is obtained when the liquid generated from the skin is in contact with the coating film.

5. A method for evaluating an emulsified composition according to any one of claims 1 to 4, wherein the liquid is sweat.

6. The evaluation step includes calculating a characteristic quantity indicating a change in the state of the coated film of the emulsified composition, and evaluating the properties of the coated film of the emulsified composition using the characteristic quantity as an indicator, the method for evaluating an emulsified composition according to any one of claims 1 to 4.

7. The characteristic of the coating film of the emulsified composition is the adhesion of the coating film of the emulsified composition. The method for evaluating an emulsified composition according to claim 6, wherein the aforementioned characteristic quantity is a characteristic quantity relating to the lifting of the applied film of the emulsified composition from the skin and / or a characteristic quantity relating to exposed skin.

8. The method for evaluating an emulsified composition according to any one of claims 1 to 4, wherein the cross-sectional image is an optical coherence tomography image.

9. The method for evaluating an emulsified composition according to claim 8, wherein the optical coherence tomography image is obtained using infrared light.

10. An evaluation apparatus for emulsified compositions, comprising an evaluation unit that evaluates the properties of the coated film of the emulsified composition based on a cross-sectional image in the depth direction of the skin obtained while the coated film of the emulsified composition formed on the skin is in contact with a liquid.

11. An evaluation program for an emulsified composition, which causes a computer to function as an evaluation unit that evaluates the properties of the coated film of the emulsified composition based on a cross-sectional image of the skin in the depth direction obtained when the coated film of the emulsified composition formed on the skin is in contact with a liquid.

12. A cross-sectional image acquisition unit acquires a cross-sectional image in the depth direction of skin on which an emulsion composition coating film has been formed, The system includes an evaluation unit that evaluates the properties of the coating film of the emulsified composition based on the cross-sectional image acquired by the cross-sectional image acquisition unit, The cross-sectional image acquisition unit is an evaluation system for emulsified compositions that acquires the cross-sectional image while the coating film and the liquid are in contact.

13. An evaluation step in which the properties of the coating film of the emulsified composition are evaluated based on a cross-sectional image of the skin in the depth direction obtained when the coating film formed on the skin using the emulsified composition prepared using the emulsifier of the test is in contact with a liquid, A selection step in which an emulsifier that was deemed suitable in the evaluation step for the properties of the coating film is selected as an emulsifier to be incorporated into the cosmetic composition, A method for designing emulsified cosmetics, comprising the following features.

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