KR20230078557A - Evaluation method for skin-tailored moisturizing ability by age - Google Patents

Abstract

The present invention provides a method for evaluation skin-tailored moisturizing ability by age, which enables low-cost, high-efficiency and reproducible evaluation, and establishes a moisturizing ability evaluation system for the future cosmetics market by evaluating the moisturizing ability of a product and suggesting correlation with human testing, and at the same time, obtains more quantitative and reproducible properties than existing human testing.

Description

Evaluation method for skin-tailored moisturizing ability by age}

The present invention relates to a method for evaluating skin moisturizing ability customized for each age using artificial skin for each age.

Artificial skin is a skin mimic obtained by recombining skin components such as skin cells and extracellular matrix in three dimensions using tissue engineering technology. It has the advantage of being able to expand the research area to areas that were previously impossible because they complement each other and have fewer research limitations. In addition, artificial skin has become an alternative to animal testing for the ban on animal testing for the development of products (cosmetics, etc.) that are not related to human life, led by the European Union (EU), and antipathy to animal testing worldwide. has become an essential element for

On the other hand, human skin undergoes changes in skin structure as aging progresses, and the most characteristic change is a decrease in skin stiffness. The reason for the decrease can be explained by the decrease in the amount of extracellular matrix in the dermal layer of the skin. In particular, it is the result of a significant decrease in the amount of collagen and elastin.

In other words, according to age (degree of aging), skin shows differences in crosslinking and bonding strength of extracellular matrix, and the extracellular matrix, which provides a physical environment in which cells can attach and grow in the human body, not only plays a structural role as a cell support, but also , Because it plays a role as a cell physiological regulator that is very important for cell growth, proliferation, and differentiation, world leading cosmetics companies such as Loreal and MatTek are also trying to develop age-specific artificial skin. It shows a marked difference from the integrated artificial skin development.

Therefore, the inventors of the present invention evaluated the moisturizing ability using live full-thickness cultured skin, and utilized the age-specific full-thickness cultured skin in which the extracellular matrix properties were controlled according to age, and analyzed the efficacy / effect of the product according to age, and the moisturizing function In addition to the evaluation, various efficacy evaluations were attempted.

The problem to be solved by the present invention is to evaluate the moisturizing ability of the product and present a correlation with the human test, thereby establishing a moisturizing ability evaluation system for the future cosmetic market, and at the same time, quantitative and reproducible evaluation results more easily than existing human tests It is to provide an alternative animal test method for skin moisturizing ability tailored to each age using artificial skin for each age that can be obtained.

The present invention is a method for evaluating skin moisturizing ability tailored to each age in order to solve the above problems. The first step of manufacturing artificial skin simulated with different concavo-convex structures for each age, liquid crystal emulsification on the artificial skin simulated with different concavo-convex structures for each age. And a second step of applying a non-liquid crystal emulsified product and a third step of deriving the water loss rate (%) of the artificial skin by the following equations (1) and (2); It provides a method for evaluating skin-specific moisturizing ability for each age, including a.

In addition, according to one embodiment of the present invention, the artificial skin simulated with different concavo-convex structures for each age in the first step includes a dermis layer into which ECM derived substances are introduced; an epidermis layer comprising sequentially stacked stratum corneum and epidermis (Human Epidermis) cell layers and provided on top of the dermis layer; and an epidermal-dermal junction provided between the dermal layer and the epidermal layer; It may be characterized by including.

In addition, according to one embodiment of the present invention, the artificial skin simulated with different concavo-convex structures for each age in the first step is simulated so that the difference in height between the ridge and valley of the concavo-convex structure formed on the surface of the dermal layer has different values for each age. can be characterized as being

In addition, the artificial skin simulated with different concavo-convex structures according to age in the first step may be characterized in that the average of the difference in height between the ridge and valley of the concavo-convex structure formed on the surface of the dermal layer has a different value for each age.

In addition, in the artificial skin simulated with different concavo-convex structures according to age in the first step, in the case of artificial skin aged 20 to less than 40 years old, the average difference in height between peaks and valleys of the concavo-convex structure is 100 μm or more to 200 μm. or less, and in the case of artificial skin aged 40 to less than 60 years of age, the average height difference between peaks and valleys of the concave-convex structure is 50 μm to less than 100 μm, and in the case of artificial skin aged 60 years or more, the unevenness It may be characterized by having a structure and physical properties for each age in which the average difference in height between peaks and valleys of the structure is less than 50 μm.

In addition, in the case of artificial skin aged 20 to less than 40 years of age, the elastic modulus is 20 to 30 kPa, in the case of artificial skin aged 40 to less than 60 years old, the elastic modulus is 10 to 20 kPa, and in the case of artificial skin aged 60 years or older In the case of skin, it may be characterized by having an elastic modulus of 10 kPa or less, structure and physical properties by age.

In addition, the artificial skin simulated with different concavo-convex structures according to age in the first step may be characterized in that the average of the difference in height between the ridge and valley of the concavo-convex structure formed on the surface of the dermal layer has a different value for each age.

In addition, the present invention provides a method for providing age-specific moisturizing cosmetics using the above-described age-specific skin moisturizing ability evaluation method.

The present invention enables low-cost, high-efficiency reproducible evaluation, evaluates the moisturizing ability of products and presents correlation with human tests, thereby establishing a moisturizing ability evaluation system for the cosmetics market in the future, and at the same time, quantitative and reproducible Evaluation results can be obtained more easily.

1 is a photograph showing the dermis layer of artificial skin having structure and physical properties by age according to an embodiment of the present invention.
2 is a photograph showing an automatic measurement system for simulating the body environment, which is an animal alternative test method for evaluating moisturizing ability using artificial skin according to the present invention.
3 is a diagram showing a method of manufacturing artificial skin for each age according to an embodiment of the present invention.
4 is a diagram showing a method for manufacturing a dermal layer according to an embodiment of the present invention.
5 is a graph showing the water loss rate in non-liquid crystal and liquid crystal sample application and control (no application) according to each age of 20's, 40's and 60's.
Figure 6 is a graph showing the water loss rate in artificial skin in their 20s, 40s, and 60s according to the applied samples of non-liquid crystal lotion, liquid crystal lotion, and control group (no application).
7 is a graph showing the water loss rate (Flux) per specific surface area in non-liquid crystal and liquid crystal samples applied and in a control group (no application) according to each age of 20s, 40s, and 60s.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

Conventional methods for evaluating the moisturizing ability of skin by age have been difficult to use in practice due to prohibitions on animal testing methods and fundamental problems in evaluating the efficacy of cosmetics on actual skin, which has practical limitations.

Accordingly, the present invention is a method for evaluating skin moisturizing ability tailored to each age. The first step of manufacturing artificial skin simulated with different concave-convex structures for each age, liquid crystal emulsified and non-liquid crystal emulsified products are applied to the artificial skin simulated with different concave-convex structures for each age. Solving the above problems by providing a method for evaluating skin moisturizing ability tailored to each age, including a second step of applying and a third step of deriving the water loss rate (%) of the artificial skin by Equations (1) and (2) below searched for.

[Equation 1]

[Equation 2]

In Equations 1 and 2 above,

wherein m ₀ is the initial mass of the artificial skin,

The m _t is the mass of the sample at an arbitrary time t (h).

Through this, the present invention enables low-cost, high-efficiency reproducible evaluation, evaluates the moisturizing ability of the product and presents a correlation with the human test, thereby establishing a moisturizing ability evaluation system for the future cosmetic market, and at the same time, quantitative and Reproducible evaluation results can be obtained more easily.

Referring to FIGS. 1 to 7, a method for evaluating skin moisturizing ability tailored to each age according to the present invention will be described.

The first step of the method for evaluating skin moisturizing ability tailored to each age according to the present invention is a step of manufacturing artificial skin simulated with a concavo-convex structure to be different for each age.

Manufacturing the artificial skin of the first step again (1-1) introducing ECM derived substances into the dermis layer to adjust mechanical properties, (1-2) extracellular matrix-derived substances By seeding the epidermal (Hμman Epidermis) cells on the dermal layer into which the matrix-derived material was introduced, the epidermal cell-derived Dermal-Epidermal Junction was formed on the surface of the dermal layer into which the extracellular matrix-derived material was introduced. and (1-3) differentiating epidermal cells to form a stratum corneum on epidermal cells to prepare artificial skin having age-specific structures and physical properties.

First, a step (1-1) of adjusting mechanical properties by introducing ECM derived substances into the dermis layer will be described.

The dermal layer can be used without limitation as long as it is a material that can be commonly used in the art to form the dermal layer of artificial skin, and preferably can be implemented by including fibroblasts (Hμman Dermal Fibroblasts).

On the other hand, the extracellular matrix-derived material performs a function of adjusting the mechanical properties of artificial skin.

Depending on the age (degree of aging), the skin shows a difference in the degree of crosslinking and bonding strength of the extracellular matrix. The extracellular matrix, which provides a physical environment in which cells can attach and grow in the human body, not only plays a structural role as a cell support, but also serves as a very important cell physiological regulator for cell growth, proliferation, and differentiation. Therefore, not only structural simulation but also mechanical properties must be controlled, which can be achieved through the introduction of extracellular matrix-derived materials. The extracellular matrix-derived material can be used without limitation as long as it can be used to form an extracellular matrix-derived material that can be conventionally introduced into the dermal layer of artificial skin in the art, preferably by mimicking the GAG (glycosaminoglycan) structure. It may include at least one selected from the group consisting of polysaccharide, elastin, chitosan, hyaluronic acid (HA), and collagen, more preferably including collagen. can be implemented

In addition, since the structure of human skin, in particular, the concavo-convex structure of the dermal-epidermal junction (DEJ) flattens as it ages, it is necessary to manufacture artificial skin for each age in which the DEJ concavo-convex structure is simulated.

Accordingly, the dermis layer of the artificial skin having structure and physical properties according to age according to an embodiment of the present invention may include a concavo-convex structure on the surface as shown in (a) to (c) of FIGS.

In addition, the concavo-convex structure of the dermis layer may be prepared in a shape-changeable hydrogel mold manufactured by one or more methods selected from the group consisting of ductility and three-dimensional lithography techniques and 3D printing, preferably in shape according to temperature. This change can be made in a shape-changeable hydrogel mold that can control the concavo-convex structure of the collagen gel in the dermal layer.

On the other hand, the shape-changeable hydrogel mold may be manufactured through a shape-changeable hydrogel mold composition having an acrylic compound including a first acrylic compound and a second acrylic compound.

The acrylic compound constitutes a random copolymer when manufacturing a shape-changeable hydrogel mold, and may include a first acrylic compound and a second acrylic compound as described above.

The first acrylic compound serves as the main structure of the shape-changeable hydrogel mold, and any first acrylic compound that is capable of polymerization and has a polymer chain structure that can be commonly used in the art can be used without limitation, preferably. is acrylamide, poly(ethylene glycol)diacrylate, methacrylated alginate, polyacrylamide, poly(ethylene glycol), methacrylate ( methacrylate), sodium polyacrylate (polyacrylate), glyceryl acrylate/acrylic acid copolymer, styrene/acrylate copolymer, sodium acrylate (sodiμm acrylate), Crosspolymer-2 , may include at least one selected from the group consisting of methyl acrylate, ethyl acrylate, normal butyl acrylate, and 2-hydroxyethyl methacrylate, Preferably, acrylamide can be used.

In addition, the second acrylic compound functions to express the sensitivity of a shape-changeable hydrogel mold, and any second acrylic compound capable of expressing sensitivity to external stimuli conventionally in the art can be used without limitation, , preferably N-isopropylacrylamide (NIPAM), acrylic acid, polyvinyl alcohol, poly N-isopropylacrylamide (pNIPAM), poly 2 -Dimethylaminoethyl methacrylate (poly 2-(dimethylamino)ethylmethacrylate, pDMAEMA), hydroxypropylcellulose, HPC, polyvinylcaprolactame, polyvinyl methylether, poly N ,N-dimethylacrylamide (poly(N,N-dimethylacrylamide)) methacrylic acid-methyl methacrylate copolymer, methacrylic acid-methyl acrylate copolymer, methacrylic acid-methyl acrylate-methyl methacrylate, and Poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r-poly(ethylene glycol) methacrylate (poly(2,2-dimethoxy nitrobenzyl methacrylate-r-methyl methacrylate-r- It may include at least one selected from the group consisting of poly(ethylene glycol)methacrylate, PDMP), and preferably N-isopropylacrylamide may be used.

At this time, when acrylamide is used as the first acryl-based compound and N-isopropylacrylamide is used as the second acryl-based compound, the shape and size of the structure to be manufactured can be controlled easily by adjusting the diameter and depth of the mold. This is easy, and as the change rate of the diameter and depth of the mold is large, it may be more advantageous to express excellent separability even when manufacturing a structure having low strength.

The acrylic compound includes the first acrylic compound and the second acrylic compound in a weight ratio of 5:5 to 1:9, preferably the first acrylic compound and the second acrylic compound in a weight ratio of 3:7 to 1:9 can include If the weight ratio of the first acrylic compound and the second acrylic compound included in the acrylic compound is less than 5:5, it is not easy to adjust the diameter and depth of the mold, so it is not easy to adjust the shape and size when manufacturing a predetermined structure. If the weight ratio exceeds 1:9, problems may occur in shape control due to rapid contraction and expansion.

On the other hand, as for the specific description other than the above description of the hydrogel mold, application number 10-2018-0147510 filed by the same applicant and inventor as the present application may be inserted as a reference, detailed description thereof should be omitted.

When the age of the target artificial skin is between 20 and 40 years old, the average height difference between peaks and valleys of the concave-convex structure may be 100 μm to 200 μm, and the target artificial skin is between 40 and 60 years of age. When the age of less than 60 years, the average height difference between peaks and valleys of the concave-convex structure may be greater than or equal to 50 μm and less than 100 μm. It may be less than 50 μm. In addition, the distance between the valley of the concavo-convex structure and other valleys adjacent to the valley may be 250 μm or less, and as these are satisfied, artificial skin for each age similar to the internal structure of human skin for each age may be realized.

Next, by seeding epidermal (Hμman Epidermis) cells on the dermal layer into which the extracellular matrix-derived material was introduced, the epidermal cell-derived epidermal-dermal junction (Dermal-Epidermal Junction) was formed on the surface of the dermal layer into which the extracellular matrix-derived material was introduced. ) The step (1-2) of culturing until formation is described.

The epidermal cells can be used without limitation as long as they are materials that can be commonly used as epidermal cells of artificial skin in the art, and preferably include keratinocytes.

In addition, the culture in step (1-2) can be used without limitation as long as it is a method that can be used for cell culture conventionally in the art, preferably it can be carried out by submerged culture, more preferably It can be performed as a submerged culture containing DMEM culture media.

On the other hand, in step (1-2), the epidermal cells are cultured until the epidermal cell-derived Dermal-Epidermal Junction is formed on the surface of the dermal layer into which the extracellular matrix-derived material has been introduced. The epidermal-dermal junction (DEJ) can perform not only a mechanical support role, but also a function of helping the proliferation and differentiation of the epidermal cells, facilitating the movement of metabolites, and improving the adhesion between the dermis and epidermis.

Next, steps (1-3) of producing artificial skin having age-specific structures and physical properties by differentiating epidermal cells to form a stratum corneum on epidermal cells will be described.

In the step (1-3), the epidermal cells may be differentiated through one or more methods selected from air exposure and ALIC (air-liquid interface culture), and preferably, the epidermal cells containing a certain amount of Ca ²⁺ It can be differentiated through ALIC (air-liquid interface culture) using a medium inducing differentiation.

By forming the stratum corneum on the epidermal cell layer through the above differentiation, it is possible to finally implement artificial skin having age-specific structures and physical properties. On the other hand, when the age of the target artificial skin is 20 to less than 40 years old, the elastic modulus of the artificial skin may be 20 to 30 kPa, and when the age of the target artificial skin is 40 to 60 years old, the artificial skin The elastic modulus may be 10 to 20 kPa, and when the age of the target artificial skin is 60 years or older, the elastic modulus of the artificial skin may be 10 kPa or less. By satisfying these requirements, artificial skin for each age similar to physical properties of human skin for each age can be implemented.

On the other hand, the artificial skin having structure and physical properties according to age according to the present invention includes a dermis layer into which ECM derived substances are introduced, a stratum corneum, and an epidermis (Hμman Epidermis) cell layer that are sequentially stacked, , It may be implemented by including an epidermis layer provided on top of the dermis layer and a dermal-epidermal junction provided between the dermis layer and the epidermis layer.

At this time, as described above, the dermal layer may include a concave-convex structure on the surface, and the epidermal cell layer and the epidermal-dermal junction may have a shape corresponding to the concave-convex structure of the dermal layer.

Next, the second step of the method for evaluating skin moisturizing ability tailored to each age according to the present invention is a step of applying liquid crystal emulsified and non-liquid crystal emulsified products to the artificial skin simulated with different concavo-convex structures for each age.

At this time, the liquid crystal emulsification refers to an emulsification in which a multi-layer lamellar structure similar to skin lipid is formed, and a known conventional material can be used, so it is not particularly limited. A non-limiting example of this may be emulsification using ceramide, cholesterol, fatty acid, and higher alcohol as a surfactant, which can confirm the maltachrous structure of skin lipids with a polarizing microscope. In addition, it may be advantageous to restore the skin barrier when applied to the skin.

In this case, the non-liquid crystal emulsification refers to any emulsification other than liquid crystal emulsification, and conventional materials known in the art may be used, so there is no particular limitation. A non-limiting example of this may be emulsification using polysorbate or sorbitan oleate as a surfactant, which may be advantageous for moisturizing when applied to the skin.

In addition, the liquid crystal emulsion and the non-liquid crystal emulsion may be applied in an amount of 0.001 g to 1 g, more preferably 0.002 g to 0.05 g, based on the weight part of the artificial skin for each age of each subject to be applied. At this time, if the liquid crystal emulsion and the non-liquid crystal emulsion are less than 0.001g with respect to the weight part of the artificial skin for each age of the target to be applied, the application may be difficult, and if the liquid crystal emulsion and the non-liquid crystal emulsion are applied to the artificial skin for each age of the target to be applied If the amount exceeds 1 g per part by weight, there may be a problem in that the function is deteriorated due to an excessive application amount.

On the other hand, by using liquid crystal emulsification and non-liquid crystal emulsification products on artificial skin for each age, the mass is measured every 30 minutes to 2 hours from 6 to 48 hours after application, and through a three-step automatic measurement system to be described later, moisturizing ability tailored to the skin by age can be evaluated.

Next, the third step of the method for evaluating skin moisturizing ability tailored to each age according to the present invention is a step of deriving the water loss rate (%) of the artificial skin by the following equations (1) and (2).

[Equation 1]

[Equation 2]

In Equations 1 and 2 above,

wherein m ₀ is the initial mass of the artificial skin,

The m _t is the mass of the sample at an arbitrary time t (h).

At this time, the method of evaluating the water loss rate (%) using Equations 1 and 2 in the third step can utilize an automatic measurement system simulating the human body environment as an alternative to animal testing.

That is, referring to FIG. 2, the automatic measurement system according to the present invention may be composed of a constant temperature and humidity chamber, a moisture evaporation measuring unit, and an operating program. The temperature setting range of the chamber may be 4 to 50 degrees, the humidity setting range is 10 to 80%, the measurement specimen part can measure 10 or more specimens at the same time, and the temperature can be set within the range of 10 to 60 degrees.

In addition, since a scale can be mounted on the lower part of the specimen part, the change in mass can be automatically measured, the temperature of the constant temperature and humidity chamber can also be set, the experiment time and measurement interval can be set, and the moisture loss rate (%) and the loss rate per comparative area ( flux) can be automatically calculated.

As such, according to the age-specific skin moisturizing ability evaluation method according to the present invention, low-cost, high-efficiency reproducible evaluation is possible, and the moisturizing ability evaluation system of the future cosmetics market by evaluating the moisturizing ability of the product and presenting correlation with the human body test At the same time, it is possible to obtain quantitative and reproducible evaluation results more easily than existing human tests. Accordingly, the present invention provides a method for providing age-specific moisturizing cosmetics by using a skin moisturizing ability evaluation method customized for each age.

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. This invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

Preparation Examples 1 to 3

First, an acrylic compound containing acrylamide as a first acrylic compound and N-isopropylacrylamide as a second acrylic compound in a weight ratio of 2:8, and N,N'-methylenebis as a crosslinking agent based on 100 parts by weight of the acrylic compound. 0.1 part by weight of acrylamide (N,N'-methylenebisacrylamide), 1 part by weight of ammonium persulfate as an initiator, 0.1 part by weight of tetramethylethylenediamine as a catalyst, and 88.8 parts by weight of water as a solvent A shape-changeable hydrogel mold was prepared by a radical polymerization reaction method through a shape-changeable hydrogel mold composition comprising the same.

At this time, the shape-changeable hydrogel mold was prepared in Preparation Example 1 to Preparation Example 3 according to the concavo-convex structure of artificial skin by age.

At this time, the preparation example 1 was prepared to have a diameter and spacing of 100 to 200 μm, and an average difference in height between peaks and valleys of the concavo-convex structure of 150 μm.

In addition, Preparation Example 2 was prepared to have holes having a diameter and spacing of 50 to 100 μm and an average difference in height between peaks and valleys of the concave-convex structure of 50 μm.

In addition, in Preparation Example 3, holes were prepared with a diameter and spacing of 0 to 50 μm and an average difference in height between peaks and valleys of the concave-convex structure of 0 μm.

Example 1 - Manufacture of artificial skin in 20's

Artificial skin having structure and physical properties for each age was manufactured through the same method as shown in FIG. 3 . Specifically, first, a dermal layer was formed using human dermal fibroblasts as cells forming the dermal layer, a concavo-convex structure was introduced, and collagen was introduced as an extracellular matrix-derived material.

In addition, as an extracellular matrix-derived material to control the strength, methacrylic alginate (MA) with a methacrylate functional group introduced into alginate was applied and 4.8 mg/ml was used based on the concentration of collagen 4.8 mg/ml.

At this time, the mechanical strength was manufactured to be formed at 25 (± 5) kPa, and the introduction of the concavo-convex structure was prepared in Preparation Example 1 having holes with a diameter and spacing of 100-200 μm and a depth of 100 μm in order to increase the roughness. It was used when preparing the dermal layer. (FIG. 4) Then, keratinocytes are seeded with human epidermis cells on the dermal layer into which the concave-convex structure has been introduced to form a dermal-epidermal junction derived from epidermal cells on the surface of the dermal layer. It was cultured through submerged culture until it was formed.

Example 2 - Manufacture of artificial skin in 40's

It was prepared in the same manner as in Example 1, but 2.4 mg/ml of methacrylic alginate (MA) was used based on the concentration of collagen 4.8 mg/ml, and the mechanical strength was formed at a concentration of 15 (± 5) kPa. Example 2 was prepared using the mold prepared in Preparation Example 2.

Example 3 - Manufacture of artificial skin in 60's

It was prepared in the same manner as in Example 1, but methacrylic alginate (MA) was used at 0 mg/ml based on the collagen concentration of 4.8 mg/ml, and the mechanical strength was formed at a concentration of 5 (± 5) kPa. and Example 3 was prepared using the mold prepared in Preparation Example 3.

Experimental example

For Examples 1 to 3, the moisturizing ability was evaluated through the measuring instrument shown in FIG. At this time, liquid crystal emulsification and non-liquid crystal emulsification products (manufacturer name or brand name, capacity, respectively) were used on each artificial skin, and the mass was measured every hour until 24 hours after application. After this, the control method experiment was performed 3 times in the chamber.

Thereafter, each of the artificial skins was stored in a dryer at a temperature of 60 degrees for 24 h to completely dry, and the mass was measured using an electronic balance. The moisture loss rate (%) of the artificial skin for each age group in the 20s, 40s, and 60s was calculated by the following equations (1) and (2) did

[Equation 1]

[Equation 2]

In Equations 1 and 2 above,

wherein m ₀ is the initial mass of the artificial skin,

The m _t is the mass of the sample at an arbitrary time t (h).

Hereinafter, it will be described with reference to the derived water loss rate and FIGS. 5 to 7.

Referring to FIG. 5, it can be seen that the water loss rate in the non-liquid crystal and liquid crystal samples applied and the control group (no application) according to each age of 20s, 40s, and 60s.

In other words, even for skin in their twenties, the water loss rate increased over time by age group, and the water loss rate decreased in the order of application of the unapplied control group, non-liquid crystal lotion, and liquid crystal lotion. Among them, it can be seen that a significant difference is shown in the liquid crystal and control samples after 6 h. In addition, the moisture loss rate increased over time for skin in their 40s by age group, and the moisture loss rate decreased in the order of application of the unapplied control group, non-liquid crystal lotion, and liquid crystal lotion. Among them, non-liquid crystal and liquid crystal samples after 3h elapsed It can be seen that there is a significant difference between the liquid crystal and the control sample. In addition, it can be seen that after 6 h, there is a significant difference between the non-liquid crystal and liquid crystal samples and the liquid crystal and control samples. On the other hand, even for skin in their 60s, the water loss rate increased over time for each age group, and it was found that the water loss rate decreased in the order of application of the unapplied control group, non-liquid crystal lotion, and liquid crystal lotion. Among them, liquid crystal after 1 hour, It can be seen that there is a significant difference between the control sample and the liquid crystal and control sample after 3 h, and a significant difference between the liquid crystal and control sample after 6 h.

Significant differences in the liquid crystal and non-liquid crystal samples appeared only in the skin in their 40s, but after 6 h, significant differences were found in all liquid crystal and control samples in the skin in their 20s, 40s, and 60s, and no significant difference was found in the non-liquid crystal and control samples. It can be seen that there is a difference in water loss between liquid crystal and non-liquid crystal samples.

Referring to FIG. 6, it can be seen that the water loss rate in artificial skin in the 20s, 40s, and 60s according to the applied samples of the non-liquid crystal lotion, the liquid crystal lotion, and the control group (no application).

Overall, the water loss rate of each sample increased over time, and the water loss rate increased in the order of application of the product to the full-thickness cultured skin in the 20s, 40s, and 60s, with the lowest water loss rate in the 20s and the lowest moisture loss in the 60s. It can be seen that the loss rate was the highest.

Even in the non-liquid crystal samples, the water loss rate increased with time, and it can be seen that the water loss rate increased in the order of application of the product to the full-thickness cultured skin of 20s, 40s, and 60s, among which, after 3h, 20s and 40s It can be seen that only significant differences are shown.

In addition, it can be seen that the water loss rate increased with time in the liquid crystal sample, and the water loss rate increased in the order of application of the product to the full-thickness cultured skin of people in their 20s, 40s, and 60s. Among them, after 3 hours, there was a significant difference between those in their 20s and 60s, and those in their 40s and 60s, and after 6 hours, significant differences were found in the skin of those in their 40s and 60s. can know that

On the other hand, in the control sample, it can be seen that there is a difference by age in the data, but there is no significant difference.

Referring to FIG. 7, it can be seen that the water loss rate (Flux) per specific surface area in the non-liquid crystal and liquid crystal samples applied and the control group (no application) according to each age of 20s, 40s, and 60s.

. When measuring the moisture evaporation of the full-layer cultured skin, there was a difference in the amount of water evaporation for each product applied up to 6 h and for each full-layer cultured skin for each age, but since the remaining moisture content almost disappeared, no significant results could be obtained. sound can be heard Therefore, the evaluation of the moisturizing ability of the water loss rate per specific surface area was evaluated up to 6h and the result was derived. When checking the water loss rate (flux) per specific surface area by dividing into artificial skin by age, the water loss rate increased as the age increased, and a significant difference was confirmed in the liquid crystal of the 20's skin and the control sample. In addition, when checking the water loss rate (flux) per specific surface area by classifying each sample, a significant difference was confirmed in the skin of the 20s and 40s of the non-liquid crystal sample, and of the skin of the 20s and 60s of the liquid crystal sample A significant difference can be identified.

As such, the present invention was able to confirm different moisturizing abilities according to skin age, and through this, it was confirmed that when developing a product, it can be designed to show appropriate moisturizing results according to the target age. In addition, through evaluation by age, the higher the age, the higher the water loss rate regardless of the product applied. Therefore, regardless of the applied sample, the highest water loss rate was found in the artificial skin in the 60s, which is due to the internal As shown by the difference in cross-linking, it can be said that the skin in the 60s with the least degree of cross-linking has the greatest loss of moisture due to the low strength of the dermal layer, and it can be said that it is a similar result to the actual skin.

On the other hand, overall, regardless of the applied product, the higher the age, the higher the water loss rate. In addition, there was almost no difference in water loss rate between the application of non-liquid crystal lotion and liquid crystal lotion on skin in their 20s, but the difference in water loss rate between non-liquid crystal lotion and liquid crystal lotion appeared large in skin in their 60s, as the age increased. It can be seen that the moisturizing effect is excellent and that products similar to the skin structure should be used.

Through this, the present invention enables low-cost, high-efficiency reproducible evaluation, evaluates the moisturizing ability of the product and presents a correlation with the human test, thereby establishing a moisturizing ability evaluation system for the future cosmetic market, and at the same time, quantitative and Reproducible evaluation results can be obtained more easily.

Claims (8)

As a method for evaluating skin moisturizing ability tailored to each age,
A first step of manufacturing artificial skin simulated with different concavo-convex structures by age;
A second step of applying liquid crystal emulsification and non-liquid crystal emulsification products to the artificial skin simulated with different concavo-convex structures by age; and
A third step of deriving the water loss rate (%) of the artificial skin by Equations (1) and (2) below; Age-specific skin moisturizing ability evaluation method including
[Equation 1]

[Equation 2]

In Equations 1 and 2 above,
wherein m ₀ is the initial mass of the artificial skin,
The m _t is the mass of the sample at an arbitrary time t (h).
According to claim 1,
The artificial skin simulated with different concavo-convex structures for each age in the first step,
Dermis layer into which ECM derived substances are introduced; an epidermis layer comprising sequentially stacked stratum corneum and epidermis (Human Epidermis) cell layers and provided on top of the dermis layer; and
Epidermal-dermal junction (Dermal-Epidermal Junction) provided between the dermal layer and the epidermal layer; Age-specific skin moisturizing ability evaluation method comprising a.
According to claim 1,
The artificial skin simulated with different concavo-convex structures for each age in the first step,
Age-specific skin moisturizing ability evaluation method, characterized in that the difference in height between the ridge and the valley of the concave-convex structure formed on the surface of the dermal layer is simulated to have different values for each age.
According to claim 1,
The artificial skin simulated with different concavo-convex structures for each age in the first step,
Age-specific skin moisturizing ability evaluation method, characterized in that the uneven structure formed on the surface of the dermal layer has different values for the average of the difference in height between the ridge and valley.
According to claim 1,
The artificial skin simulated with different concavo-convex structures for each age in the first step,
In the case of artificial skin between the ages of 20 and 40, the average height difference between peaks and valleys of the concave-convex structure is 100 μm to 200 μm, and in the case of artificial skin between 40 and 60 years of age, the above The average height difference between peaks and valleys of the concave-convex structure is 50 μm to less than 100 μm, and in the case of artificial skin aged 60 years or older, the average height difference between peaks and valleys of the concavo-convex structure is less than 50 μm. Age-specific skin moisturizing ability evaluation method characterized in that it has physical properties.
According to claim 1,
In the case of artificial skin aged 20 to 40 years old, the modulus of elasticity is 20 to 30 kPa,
In the case of artificial skin aged 40 to 60 years old, the modulus of elasticity is 10 to 20 kPa,
In the case of artificial skin aged 60 years or older, the modulus of elasticity is less than 10 kPa,
Age-specific skin moisturizing ability evaluation method, characterized in that it has a structure and physical properties by age.
According to claim 1,
The artificial skin simulated with different concavo-convex structures for each age in the first step,
Age-specific skin moisturizing ability evaluation method, characterized in that the uneven structure formed on the surface of the dermal layer has different values for the average of the difference in height between the ridge and valley.
A method of providing age-specific moisturizing cosmetics using the age-specific skin moisturizing ability evaluation method according to any one of claims 1 to 7.

Images