Cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling and method for preparing thereof

Abstract

The present invention relates to a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling and a method for manufacturing the same. More specifically, the invention relates to a cosmetic composition for daily home care and a method for manufacturing the same, which uses a hydrangea extract containing hydrangenol as a main active ingredient and combines a complex peeling active ingredient, a multilayer moisturizing ingredient, and a multifunctional elasticity-enhancing ingredient in a scientifically optimized mixing ratio to provide a low-irritation peeling effect along with skin moisturizing and elasticity-enhancing effects simultaneously. The cosmetic composition of the present invention comprises a hydrangea extract prepared by hot water extraction of hydrangea leaves, wherein the hydrangea extract contains 0.5 to 2.0 weight% of hydrangenol, a combination of AHA, BHA, PHA and an enzyme peeling agent as peeling active ingredients, hyaluronic acid, glycerin, butylene glycol, dipropylene glycol and natural moisturizing factors of various molecular weights as moisturizing ingredients, and various peptides, adenosine, retinol derivatives and plant collagen precursors as elasticity-enhancing ingredients.

Description

Technology Field

[0001] The following examples relate to a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling, and a method for manufacturing the same. Background Technology

[0002] Skin aging is classified into intrinsic and extrinsic aging and is accompanied by symptoms such as skin dryness, wrinkle formation, and decreased elasticity. In particular, skin hydration is an essential element for maintaining skin homeostasis; skin dryness is a major cause of wrinkle formation and negatively affects skin cell function.

[0003] Methods to improve skin hydration have primarily focused on increasing the expression of hyaluronic acid synthases such as HAS-1, HAS-2, and HAS-3, or inhibiting the activity of hyaluronidase. Additionally, approaches to reduce transepidermal water loss by strengthening skin barrier factors such as filaggrin, transglutaminase-1, occludin, and involucrin are also being utilized.

[0004] Meanwhile, peeling products are effective in promoting skin regeneration and improving skin texture by removing dead cells from the skin surface. Conventional peeling products utilize chemical peeling agents such as AHA (Alpha Hydroxy Acid), BHA (Beta Hydroxy Acid), and PHA (Poly Hydroxy Acid), as well as enzyme peeling agents. However, these products have drawbacks, such as high chemical content that can cause skin irritation and low repurchase rates due to the difficulty of frequent use.

[0005] Hydrangea serrata is a plant native to the mountainous regions of Korea and Japan, and its leaves have traditionally been consumed as tea. Hydrangea extracts contain various polyphenol compounds, including hydrangenol, and recent studies have reported anti-obesity, muscle synthesis-promoting, and anti-photoaging effects. In particular, hydrangenol is a natural compound of the dehydroisocoumarin family known for its anti-allergic, antifungal, anti-inflammatory, anti-diabetic, and anti-angiogenic effects.

[0006] Recent studies have reported that hot water extract of hydrangea increases the expression of hyaluronic acid synthase and decreases the expression of hyaluronidase, and promotes collagen synthesis through the activation of the AP-1 and Akt / PI3K pathways. Additionally, clinical trials using a cream containing 0.5% hydrangea extract for 4 weeks confirmed a significant increase in skin hydration and a reduction in wrinkle depth.

[0007] However, existing studies have focused only on the single effects of hydrangea extract, and have not specifically presented a cosmetic composition or a method for manufacturing the same that simultaneously achieves low-irritation peeling, moisturizing, and elasticity-enhancing effects by combining peeling active ingredients, moisturizing ingredients, and elasticity-enhancing ingredients. Prior art literature

[0008] Korean Published Patent 10-2014-0082555 Korean Published Patent 10-2016-0024675 Korean Registered Patent 10-1946526 Korean Registered Patent 10-1934022 The problem to be solved

[0009] The present invention develops a cosmetic composition that solves the problem of skin irritation caused by strong chemical components in existing peeling products and provides a low-irritation yet effective peeling function.

[0010] In addition, unlike existing products that provide only a peeling function, the present invention provides a multifunctional cosmetic composition that can be used daily for daily home care by providing a combination of peeling, skin moisturizing, and elasticity-enhancing effects simultaneously.

[0011] In addition, the present invention provides a cosmetic composition that exhibits a synergistic effect between each ingredient by combining a peeling active ingredient, a moisturizing ingredient, and an elasticity-enhancing ingredient in a scientifically optimized ratio to maximize the skin-improving effect of hydrangenol contained in hydrangea extract.

[0012] In addition, the present invention provides an effective method for manufacturing the cosmetic composition, and specifically defines the preparation step, mixing order, mixing conditions, formulation conditions, homogenization conditions, etc. of each component to provide a manufacturing method that ensures the stability and efficacy of the product.

[0013] In addition, the present invention provides a method for quantitatively managing and standardizing the content of hydranzenol, an active ingredient of hydrangea extract, thereby ensuring product quality consistency and reproducibility of efficacy.

[0014] In addition, the present invention provides a method for manufacturing a cosmetic composition that exhibits optimal absorption and efficacy when applied to the skin, including quality control steps such as pH control, viscosity control, and particle size control. means of solving the problem

[0015] The present invention relates to a method for preparing a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling, wherein a hydrangea extract, a peeling active ingredient, a moisturizing ingredient, and an elasticity-enhancing ingredient are each prepared, mixed, and then formulated and homogenized.

[0016] At this time, (a) a step of preparing a hydrangea extract by extracting the leaves of *Hydrangea serrata* with hot water to prepare a hydrangea extract, wherein the hydrangea extract is prepared to contain 0.5 to 2.0 weight% of hydrangenol; (b) a step of preparing a peeling active ingredient, wherein the peeling active ingredient comprises AHA (Alpha Hydroxy Acid), BHA (Beta Hydroxy Acid), PHA (Poly Hydroxy Acid), and an enzyme peeling agent; (c) a step of preparing a moisturizing ingredient, wherein the moisturizing ingredient comprises hyaluronic acid, glycerin, butylene glycol, dipropylene glycol, and natural moisturizing factors; (d) a step of preparing an elasticity-enhancing ingredient, wherein the elasticity-enhancing ingredient comprises peptides, adenosine, retinol derivatives, and plant collagen precursors; (e) a mixing step of preparing a mixture by mixing 5 to 30 parts by weight of the hydrangea extract from step (a), 1 to 15 parts by weight of the peeling active ingredient from step (b), 10 to 40 parts by weight of the moisturizing ingredient from step (c), and 1 to 20 parts by weight of the elasticity-enhancing ingredient from step (d); (f) a formulation step of preparing a weakly acidic cosmetic composition with a pH in the range of 5.0-6.5 by further adding an emulsifier, a thickener, a preservative, and a pH adjuster to the mixture from step (e); and (g) a homogenization step of obtaining a final cosmetic composition by homogenizing the cosmetic composition from step (f).

[0017] At this time, the above step (a) is a step of preparing raw materials by washing and hot-air drying hydrangea leaves, adding purified water, obtaining an extract by hot-water extraction at high temperature, obtaining a filtrate by filtering with a membrane filter, preparing a concentrate using a vacuum concentrator, obtaining hydrangea extract powder through freeze-drying or spray-drying, and preparing a hydrangea extract containing a certain amount of hydrangenol by analyzing and confirming the hydrangenol content in the hydrangea extract powder using HPLC or LC-MS / MS via a calibration curve method; and the above step (b) is a step of preparing an AHA containing glycolic acid, lactic acid, mandelic acid, and citric acid together with a solvent and a stabilizer, preparing a BHA containing salicylic acid or a derivative together with a solvent and a stabilizer, preparing a PHA containing gluconolactone or lactobionic acid together with a solvent and a stabilizer, and preparing an enzyme peeling agent containing papain, bromelain, pumpkin enzyme, and pineapple enzyme together with a solvent and a stabilizer The step of preparing, then mixing the prepared peeling active ingredients and adjusting with a solvent and a stabilizer to prepare a low-irritation peeling active ingredient mixture, and the step (c) comprises preparing low molecular weight, medium molecular weight, and high molecular weight hyaluronic acid with a solvent and a stabilizer, preparing glycerin with a solvent and a stabilizer, preparing butylene glycol with a solvent and a stabilizer, preparing dipropylene glycol with a solvent and a stabilizer, and preparing sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline as natural moisturizing factors with a solvent and a stabilizer, then mixing the prepared moisturizing ingredients and adjusting with a solvent and a stabilizer, and the step (d) comprises preparing palmitoyl pentapeptide-4, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, acetyl hexapeptide-8, copper tripeptide-1, and carnosine as peptides with a solvent and a stabilizer, and preparing adenosine with a solvent and Prepared with stabilizers, retinol, retinyl palmitate, retinyl acetate,The step of preparing a mixture of elasticity-enhancing ingredients by preparing retinaldehydride and retinoic acid as retinol derivatives with a solvent and a stabilizer, and preparing Centella asiatica extract, Korean red ginseng extract, green tea extract, aloe vera extract, and licorice extract as plant collagen precursors with a solvent and a stabilizer, and then mixing the prepared elasticity-enhancing ingredients and adjusting with a solvent and a stabilizer; the above step (e) is a step of preparing a mixture in which each ingredient is uniformly mixed by preparing a mixing container, maintaining it at an appropriate temperature, first adding moisturizing ingredients and performing a first stirring, slowly adding hydrangea extract by dropwise stirring while performing a second stirring, slowly adding peeling active ingredients by dropwise stirring while performing a third stirring, slowly adding elasticity-enhancing ingredients by dropwise stirring while performing a fourth stirring, and then performing a degassing treatment under reduced pressure conditions using a vacuum degassing machine; and the above step (f) is cetearyl alcohol, glyceryl stearate, PEG-100 stearate, The step of preparing a cosmetic composition involves preparing an emulsifier comprising sorbitan oleate and caprylyl / capryl glucoside, preparing a thickener comprising carbomer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer and polyisobutene, preparing a preservative comprising 1,2-hexanediol and phenoxyethanol, and preparing a pH adjuster comprising triethanolamine, then sequentially adding the emulsifier, thickener, and preservative to the mixture, stirring each, measuring the pH, adjusting it to a weakly acidic range using a pH adjuster, and finally stirring while cooling; and the above step (g) involves introducing the cosmetic composition into a homogenization device and performing primary homogenization using a homomixer while maintaining an appropriate temperature, performing secondary homogenization using a high-shear homogenizer, and performing tertiary homogenization by repeatedly passing through a high-pressure homogenizer, then measuring the average particle size using laser diffraction and, if necessary, adding Adjusting particle size through homogenization,This is a step of obtaining a final cosmetic composition by measuring the viscosity using a Brookfield rotational viscometer, adjusting the viscosity by adding a thickener if necessary, and then filling it into a container.

[0018] At this time, the above step (a) comprises: (a1) a step of preparing a hydrangea leaf raw material by washing the leaves of Hydrangea serrata and hot-air drying them at 40°C to 60°C for 12 to 24 hours; (a2) a step of adding 10 to 20 parts by weight of purified water to 1 part by weight of the hydrangea leaf raw material; (a3) ​​a step of obtaining an extract by hot-water extraction of the mixture from step (a2) at a temperature of 95°C to 100°C for 3 to 7 hours; (a4) a step of obtaining a filtrate by filtering the extract obtained from step (a3) ​​through a membrane filter with a pore size of 5㎛ to 15㎛; and (a5) a step of obtaining a concentrate by concentrating the filtrate obtained from step (a4) using a vacuum concentrator at a temperature of 60°C to 80°C under reduced pressure conditions of 0.01 to 0.1 MPa. (a6) A step of obtaining hydrangea extract powder by freeze-drying or spray-drying the concentrate obtained in step (a5) above at -80°C for at least 48 hours in the case of freeze-drying, or at an inlet temperature of 150°C to 180°C and an outlet temperature of 80°C to 100°C in the case of spray-drying; and (a7) a step of confirming that the hydrangenol content in the hydrangea extract powder obtained in step (a6) is 0.5 wt% to 2.0 wt% by analyzing the hydrangenol content in the hydrangea extract powder obtained in step (a6) using a calibration curve method with a hydrangenol standard substance using HPLC (High Performance Liquid Chromatography, mobile phase: acetonitrile / water gradient solvent, detection wavelength: 280 nm) or LC-MS / MS (Liquid Chromatography-Tandem Mass Spectrometry, electrospray ionization mode) with a C18 column.

[0019] At this time, the above step (b) comprises: (b1) a step of preparing an AHA (Alpha Hydroxy Acid) comprising 0.1 to 1.0 wt% glycolic acid, 0.1 to 0.8 wt% lactic acid, 0.1 to 0.7 wt% mandelic acid, and 0.1 to 0.5 wt% citric acid, wherein the remainder consists of a solvent and a stabilizer; (b2) a step of preparing a BHA (Beta Hydroxy Acid) comprising salicylic acid or its derivative at a concentration of 0.1 wt% to 2 wt%, wherein the remainder consists of a solvent and a stabilizer; (b3) a step of preparing a PHA (Poly Hydroxy Acid) comprising gluconolactone or lactobionic acid at a concentration of 0.5 wt% to 3 wt%, wherein the remainder consists of a solvent and a stabilizer; (b4) a step of preparing an enzyme peeling agent comprising 0.02~0.3 wt% papain, 0.02~0.25 wt% bromelain, 0.02~0.25 wt% pumpkin enzyme, and 0.02~0.2 wt% pineapple enzyme, with the remainder consisting of a solvent and a stabilizer; (b5) a step of preparing a low-irritation peeling active ingredient mixture by mixing the peeling active ingredients prepared in steps (b1) to (b4) such that the total concentration of the peeling active ingredients is 1.08 wt% to 9 wt%, with the remainder consisting of a solvent and a stabilizer;

[0020] At this time, the above step (c) comprises: (c1) preparing hyaluronic acid according to molecular weight, wherein low molecular weight hyaluronic acid with a molecular weight of less than 10 kDa, medium molecular weight hyaluronic acid with a molecular weight of 10 kDa or more and 100 kDa or less, and high molecular weight hyaluronic acid with a molecular weight of more than 100 kDa are each prepared at a concentration of 0.1 wt% to 3 wt%, and the remainder is composed of a solvent and a stabilizer; (c2) preparing glycerin at a concentration of 3 wt% to 10 wt%, and the remainder is composed of a solvent and a stabilizer; (c3) preparing butylene glycol at a concentration of 2 wt% to 8 wt%, and the remainder is composed of a solvent and a stabilizer; (c4) preparing dipropylene glycol at a concentration of 1 wt% to 5 wt%, and the remainder is composed of a solvent and a stabilizer; (c5) a step of preparing natural moisturizing factors, each comprising sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline at a concentration of 0.1% to 1% by weight, with the remainder consisting of a solvent and a stabilizer; and (c6) a step of mixing the moisturizing ingredients prepared in steps (c1) to (c5) at a temperature of 25°C to 35°C at a speed of 200 rpm to 400 rpm for 10 to 20 minutes, wherein the total concentration of the moisturizing ingredients is 6.9% to 38% by weight, with the remainder consisting of a solvent and a stabilizer; comprising

[0021] At this time, the above step (d) comprises: (d1) preparing palmitoyl pentapeptide-4, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, acetyl hexapeptide-8, copper tripeptide-1, and carnosine as peptides at a concentration of 0.001 wt% to 1 wt%, with the remainder consisting of a solvent and a stabilizer; (d2) preparing adenosine at a concentration of 0.01 wt% to 0.5 wt%, with the remainder consisting of a solvent and a stabilizer; (d3) preparing retinol derivatives such as retinol, retinyl palmitate, retinyl acetate, retinaldehydride, and retinoic acid at a concentration of 0.01 wt% to 1 wt%, with the remainder consisting of a solvent and a stabilizer; (d4) a step of preparing each of Centella asiatica extract, red ginseng extract, green tea extract, aloe vera extract, and licorice extract as plant-based collagen precursors at a concentration of 0.1% to 5% by weight, with the remainder consisting of a solvent and a stabilizer; and (d5) a step of preparing a mixture of elasticity-enhancing ingredients prepared in steps (d1) to (d4), wherein the total concentration of the elasticity-enhancing ingredients is 0.566% to 36.5% by weight, and the remainder consists of a solvent and a stabilizer; comprising.

[0022] At this time, the above step (e) comprises: (e1) preparing a mixing container and maintaining the temperature of the mixing container at 20℃ to 30℃; (e2) first adding 10 to 40 parts by weight of the moisturizing ingredient of step (c) to the mixing container and stirring first at a speed of 100 rpm to 300 rpm for 5 to 15 minutes; (e3) adding 5 to 30 parts by weight of the hydrangea extract of step (a) to the mixing container stirred first in step (e2) by a dropwise method over 3 to 10 minutes and stirring second at a speed of 250 rpm to 400 rpm for 10 to 20 minutes; (e4) a step of adding 1 to 15 parts by weight of the peeling active ingredient of step (b) to the second-stirred mixing container of step (e3) by a dropwise method over 3 to 10 minutes and stirring a third time at a speed of 150 rpm to 300 rpm for 10 to 20 minutes; (e5) a step of adding 1 to 20 parts by weight of the elasticity-enhancing ingredient of step (d) to the third-stirred mixing container of step (e4) by a dropwise method over 3 to 10 minutes and stirring a fourth time at a speed of 250 rpm to 400 rpm for 15 to 30 minutes; and (e6) a step of preparing a mixture by degassing the 4th stirred mixing vessel of step (e5) using a vacuum degassing machine for 5 to 15 minutes under vacuum conditions of 0.01 MPa to 0.05 MPa;

[0023] At this time, the above step (f) comprises: (f1) a step of preparing an emulsifier comprising 0.3 to 3 parts by weight of cetearyl alcohol, 0.2 to 2 parts by weight of glyceryl stearate, 0.2 to 2 parts by weight of PEG-100 stearate, 0.1 to 1.5 parts by weight of sorbitan oleate, and 0.2 to 1.5 parts by weight of caprylyl / capryl glucoside as an emulsifier; (f2) a step of preparing a thickener comprising 0.05 to 1.5 parts by weight of carbomer, 0.03 to 1 part by weight of sodium acrylate / sodium acryloyl dimethyl taurate copolymer, and 0.02 to 0.5 parts by weight of polyisobutene as a thickener; (f3) a step of preparing a preservative comprising 0.3 to 2 parts by weight of 1,2-hexanediol and 0.2 to 1 part by weight of phenoxyethanol as a preservative; (f4) a step of preparing a pH adjuster comprising 0.01 to 1 part by weight of triethanolamine as a pH adjuster; (f5) a step of adding the emulsifier of step (f1) to the mixture of step (e) and stirring for 10 to 20 minutes at a speed of 300 rpm to 500 rpm at a temperature of 30℃ to 50℃; (f6) a step of adding the thickener of step (f2) to the stirred mixture of step (f5) and stirring for 15 to 30 minutes at a speed of 200 rpm to 400 rpm; (f7) a step of adding the preservative of step (f3) to the stirred mixture of step (f6) and stirring at a speed of 150 rpm to 300 rpm for 5 to 15 minutes; (f8) a step of measuring the pH of the stirred mixture of step (f7) and adjusting the pH by adding the pH adjuster of step (f4) so ​​that the measured pH is in the range of 5.0 to 6.5; and (f9) a step of preparing a cosmetic composition by cooling the pH-adjusted mixture of step (f8) to 20℃ to 30℃ while performing final stirring at a speed of 100 rpm to 200 rpm for 10 to 20 minutes;

[0024] At this time, step (g) comprises: (g1) a step of introducing the cosmetic composition of step (f) into a homogenizing device; (g2) a step of maintaining the temperature of the homogenizing device at 25℃ to 35℃; (g3) a step of first homogenizing the cosmetic composition by using a homomixer at a speed of 3,000 rpm to 6,000 rpm for 5 minutes to 15 minutes; (g4) a step of secondarily homogenizing the cosmetic composition homogenized in step (g3) by using a high shear homogenizer at a speed of 8,000 rpm to 12,000 rpm for 10 minutes to 20 minutes; (g5) A step of tertiarily homogenizing the secondary homogenized cosmetic composition from step (g4) using a high-pressure homogenizer, by passing it through 3 to 4 times repeatedly under pressure conditions of 80 bar to 150 bar; (g6) A step of checking whether the average particle size of the tertiary homogenized cosmetic composition from step (g5) is in the range of 0.1 μm to 5 μm by measuring by laser diffraction after ultrasonically treating with purified water as a dispersion medium for 3 minutes at a temperature of 25°C, and if it falls outside the above range, adjusting the particle size by repeating step (g5) 1 to 2 additional times; (g7) A step of checking the viscosity of the cosmetic composition confirmed in step (g6) using a Brookfield rotational viscometer at 20°C with spindle No. The method comprises the steps of: using 5 and measuring for 1 minute at a rotational speed of 12 rpm to determine if the viscosity is in the range of 10,000 cps to 25,000 cps, and if it falls outside the range, adding a thickener to adjust the viscosity; and (g8) filling the cosmetic composition confirmed in step (g7) into a container to obtain a final cosmetic composition.

[0025] A device according to one embodiment may be combined with hardware and controlled by a computer program stored on a medium to execute the method of any one of the methods described above. Effects of the invention

[0026] The cosmetic composition of the present invention significantly increases the expression of hyaluronic acid synthases (HAS-1, HAS-2, HAS-3) by activating the AP-1 pathway and the Akt / PI3K pathway by hydrangenol contained in hydrangea extract, and at the same time reduces the expression of hyaluronidases (HYAL-1, HYAL-2, HYAL-3, HYAL-4), thereby maximizing the skin moisturizing effect.

[0027] In addition, the cosmetic composition of the present invention combines AHA, BHA, PHA, and an enzyme peeling agent as peeling active ingredients, and by adjusting the concentration of each ingredient to a low-irritation range, it creates a daily home care product that can be used every day while minimizing skin irritation while maintaining an effective exfoliation effect.

[0028] In addition, the cosmetic composition of the present invention provides a three-dimensional moisturizing effect from the surface layer to the deep layer of the skin by combining low, medium, and high molecular weight hyaluronic acids with different molecular weights, and by including various moisturizing ingredients such as glycerin, butylene glycol, and dipropylene glycol, along with natural moisturizing factors.

[0029] In addition, the cosmetic composition of the present invention combines various peptides, adenosine, retinol derivatives, and plant collagen precursors as elasticity-enhancing ingredients to promote procollagen synthesis, and in particular, increases the mRNA and protein expression of COL1A1, thereby exhibiting the effect of improving skin elasticity and reducing wrinkles.

[0030] In addition, the cosmetic composition of the present invention increases the expression of skin barrier factors such as transglutaminase-1, involucrin, occludin, and filaggrin, and promotes the expression of keratin 5, 6, and 16, thereby strengthening skin barrier function, reducing transepidermal water loss, and promoting skin cell proliferation.

[0031] In addition, the manufacturing method of the present invention maximizes the interaction between ingredients by optimizing the order of addition and stirring conditions of each ingredient, and in particular, preserves the stability and efficacy of each ingredient to the maximum extent by adopting a method of adding moisturizing ingredients first, followed by sequentially adding hydrangea extract, peeling active ingredients, and elasticity-enhancing ingredients.

[0032] In addition, the manufacturing method of the present invention includes precise quality control steps such as vacuum degassing, multi-stage homogenization, particle size measurement and control, and viscosity measurement and control, thereby optimizing the physical stability and skin absorption rate of the product.

[0033] In addition, the cosmetic composition of the present invention is formulated to be weakly acidic in the pH range of 5.0-6.5, so as to be maintained similarly to the natural pH of the skin, thereby minimizing skin irritation and protecting the skin barrier function. Specific details for implementing the invention

[0034] Embodiments are described in detail below. However, various modifications may be made to the embodiments, and thus the scope of the patent application is not limited or restricted by these embodiments. It should be understood that all modifications, equivalents, and substitutions to the embodiments are included within the scope of the rights.

[0035] Specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and may be modified and implemented in various forms. Accordingly, the embodiments are not limited to the specific disclosed forms, and the scope of this specification includes modifications, equivalents, or substitutions that fall within the technical concept.

[0036] Terms such as "first" or "second" may be used to describe various components, but these terms should be interpreted solely for the purpose of distinguishing one component from another. For example, the first component may be named the second component, and similarly, the second component may be named the first component.

[0037] When it is stated that a component is "connected" to another component, it should be understood that it may be directly connected to or coupled with that other component, or that there may be other components in between.

[0038] The terms used in the embodiments are for illustrative purposes only and should not be interpreted as intended to be limiting. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0039] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the embodiments pertain. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0040] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described in detail below. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0041] In the embodiments of the present invention, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the embodiments of the present invention.

[0042] The shapes, sizes, ratios, angles, numbers, etc. disclosed to describe embodiments of the present invention are exemplary and are not limited to the disclosed matters. Furthermore, in describing the present invention, if it is determined that a detailed description of related known technology may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "comprising," "having," or "consisting of" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it includes the plural unless specifically stated otherwise.

[0043] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0044] The size and thickness of each disclosed component are disclosed for convenience of explanation and the present invention is not necessarily limited to the size and thickness of the disclosed components.

[0045] The features of each of the various embodiments of the present invention may be combined or combined with one another, either partially or wholly, and as will be fully understood by those skilled in the art, various technical interlocking and operation are possible, and each embodiment may be implemented independently of one another or together in an interlocking relationship.

[0046] The present invention relates to a method for preparing a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling, wherein a hydrangea extract, a peeling active ingredient, a moisturizing ingredient, and an elasticity-enhancing ingredient are each prepared, mixed, and then formulated and homogenized.

[0047] At this time, (a) a step of preparing a hydrangea extract by extracting the leaves of *Hydrangea serrata* with hot water to prepare a hydrangea extract, wherein the hydrangea extract is prepared to contain 0.5 to 2.0 weight% of hydrangenol; (b) a step of preparing a peeling active ingredient, wherein the peeling active ingredient comprises AHA (Alpha Hydroxy Acid), BHA (Beta Hydroxy Acid), PHA (Poly Hydroxy Acid), and an enzyme peeling agent; (c) a step of preparing a moisturizing ingredient, wherein the moisturizing ingredient comprises hyaluronic acid, glycerin, butylene glycol, dipropylene glycol, and natural moisturizing factors; and (d) a step of preparing an elasticity-enhancing ingredient, wherein the elasticity-enhancing ingredient comprises peptides, adenosine, retinol derivatives, and plant collagen precursors; (e) a mixing step of preparing a mixture by mixing 5 to 30 parts by weight of the hydrangea extract from step (a), 1 to 15 parts by weight of the peeling active ingredient from step (b), 10 to 40 parts by weight of the moisturizing ingredient from step (c), and 1 to 20 parts by weight of the elasticity-enhancing ingredient from step (d); (f) a formulation step of preparing a weakly acidic cosmetic composition with a pH in the range of 5.0-6.5 by additionally adding an emulsifier, a thickener, a preservative, and a pH adjuster to the mixture from step (e); and (g) a homogenization step of obtaining a final cosmetic composition by homogenizing the cosmetic composition from step (f).

[0048] At this time, the above step (a) is a step of preparing raw materials by washing and hot-air drying hydrangea leaves, adding purified water, obtaining an extract by hot-water extraction at high temperature, obtaining a filtrate by filtering with a membrane filter, preparing a concentrate using a vacuum concentrator, obtaining hydrangea extract powder through freeze-drying or spray-drying, and preparing a hydrangea extract containing a certain amount of hydrangenol by analyzing and confirming the hydrangenol content in the hydrangea extract powder using HPLC or LC-MS / MS via a calibration curve method; and the above step (b) is a step of preparing an AHA containing glycolic acid, lactic acid, mandelic acid, and citric acid together with a solvent and a stabilizer, preparing a BHA containing salicylic acid or a derivative together with a solvent and a stabilizer, preparing a PHA containing gluconolactone or lactobionic acid together with a solvent and a stabilizer, and preparing an enzyme peeling agent containing papain, bromelain, pumpkin enzyme, and pineapple enzyme together with a solvent and a stabilizer The step of preparing, then mixing the prepared peeling active ingredients and adjusting with a solvent and a stabilizer to prepare a low-irritation peeling active ingredient mixture, and the step (c) comprises preparing low molecular weight, medium molecular weight, and high molecular weight hyaluronic acid with a solvent and a stabilizer, preparing glycerin with a solvent and a stabilizer, preparing butylene glycol with a solvent and a stabilizer, preparing dipropylene glycol with a solvent and a stabilizer, and preparing sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline as natural moisturizing factors with a solvent and a stabilizer, then mixing the prepared moisturizing ingredients and adjusting with a solvent and a stabilizer, and the step (d) comprises preparing palmitoyl pentapeptide-4, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, acetyl hexapeptide-8, copper tripeptide-1, and carnosine as peptides with a solvent and a stabilizer, and preparing adenosine with a solvent and Prepared with stabilizers, retinol, retinyl palmitate, retinyl acetate,The step of preparing a mixture of elasticity-enhancing ingredients by preparing retinaldehydride and retinoic acid as retinol derivatives with a solvent and a stabilizer, and preparing Centella asiatica extract, Korean red ginseng extract, green tea extract, aloe vera extract, and licorice extract as plant collagen precursors with a solvent and a stabilizer, and then mixing the prepared elasticity-enhancing ingredients and adjusting with a solvent and a stabilizer; the above step (e) is a step of preparing a mixture in which each ingredient is uniformly mixed by preparing a mixing container, maintaining it at an appropriate temperature, first adding moisturizing ingredients and performing a first stirring, slowly adding hydrangea extract by dropwise stirring while performing a second stirring, slowly adding peeling active ingredients by dropwise stirring while performing a third stirring, slowly adding elasticity-enhancing ingredients by dropwise stirring while performing a fourth stirring, and then performing a degassing treatment under reduced pressure conditions using a vacuum degassing machine; and the above step (f) is cetearyl alcohol, glyceryl stearate, PEG-100 stearate, The step of preparing a cosmetic composition involves preparing an emulsifier comprising sorbitan oleate and caprylyl / capryl glucoside, preparing a thickener comprising carbomer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer and polyisobutene, preparing a preservative comprising 1,2-hexanediol and phenoxyethanol, and preparing a pH adjuster comprising triethanolamine, then sequentially adding the emulsifier, thickener, and preservative to the mixture, stirring each, measuring the pH, adjusting it to a weakly acidic range using a pH adjuster, and finally stirring while cooling; and the above step (g) involves introducing the cosmetic composition into a homogenization device and performing primary homogenization using a homomixer while maintaining an appropriate temperature, performing secondary homogenization using a high-shear homogenizer, and performing tertiary homogenization by repeatedly passing through a high-pressure homogenizer, then measuring the average particle size using laser diffraction and, if necessary, adding Adjusting particle size through homogenization,This is a step of obtaining a final cosmetic composition by measuring the viscosity using a Brookfield rotational viscometer, adjusting the viscosity by adding a thickener if necessary, and then filling it into a container.

[0049] At this time, the above step (a) comprises: (a1) a step of preparing a hydrangea leaf raw material by washing the leaves of Hydrangea serrata and hot-air drying them at 40°C to 60°C for 12 to 24 hours; (a2) a step of adding 10 to 20 parts by weight of purified water to 1 part by weight of the hydrangea leaf raw material; (a3) ​​a step of obtaining an extract by hot-water extraction of the mixture from step (a2) at a temperature of 95°C to 100°C for 3 to 7 hours; (a4) a step of obtaining a filtrate by filtering the extract obtained from step (a3) ​​through a membrane filter with a pore size of 5㎛ to 15㎛; (a5) a step of obtaining a concentrate by concentrating the filtrate obtained from step (a4) using a vacuum concentrator at a temperature of 60°C to 80°C under reduced pressure conditions of 0.01 to 0.1 MPa; and (a6) The method comprises the step of obtaining a hydrangea extract powder by freeze-drying the concentrate obtained in step (a5) at -80°C for 48 hours or more in the case of freeze-drying, or by spray-drying under conditions of an inlet temperature of 150°C to 180°C and an outlet temperature of 80°C to 100°C in the case of spray-drying, and (a7) the step of confirming that the hydrangenol content in the hydrangea extract powder obtained in step (a6) is 0.5 wt% to 2.0 wt% by analyzing the hydrangenol content in the hydrangea extract powder obtained in step (a6) using HPLC (High Performance Liquid Chromatography, mobile phase: acetonitrile / water gradient solvent, detection wavelength: 280 nm) or LC-MS / MS (Liquid Chromatography-Tandem Mass Spectrometry, electrospray ionization mode) using a hydrangenol standard substance by a calibration curve method using HPLC (High Performance Liquid Chromatography, mobile phase: acetonitrile / water gradient solvent, detection wavelength: 280 nm) or LC-MS / MS (Liquid Chromatography-Tandem Mass Spectrometry, electrospray ionization mode) using a C18 column.

[0050] At this time, the above step (b) comprises: (b1) a step of preparing an AHA (Alpha Hydroxy Acid) comprising 0.1 to 1.0 wt% glycolic acid, 0.1 to 0.8 wt% lactic acid, 0.1 to 0.7 wt% mandelic acid, and 0.1 to 0.5 wt% citric acid, wherein the remainder consists of a solvent and a stabilizer; (b2) a step of preparing a BHA (Beta Hydroxy Acid) comprising salicylic acid or its derivative at a concentration of 0.1 wt% to 2 wt%, wherein the remainder consists of a solvent and a stabilizer; (b3) a step of preparing a PHA (Poly Hydroxy Acid) comprising gluconolactone or lactobionic acid at a concentration of 0.5 wt% to 3 wt%, wherein the remainder consists of a solvent and a stabilizer; and (b4) an enzyme peeling agent comprising 0.02 to 0.3 wt% papain, 0.02 to 0.25 wt% bromelain, and 0.02 to 0.25 wt% pumpkin enzyme. The method comprises the step of preparing a mixture of a peeling active ingredient prepared in steps (b1) to (b4) such that the total concentration of the peeling active ingredient is 1.08% to 9% by weight, and the remainder is prepared as a solvent and a stabilizer, and the step of preparing a low-irritation peeling active ingredient mixture by mixing the peeling active ingredients prepared in steps (b1) to (b4) such that the total concentration of the peeling active ingredient is 1.08% to 9% by weight, and the remainder is prepared as a solvent and a stabilizer.

[0051] At this time, the above step (c) comprises: (c1) preparing hyaluronic acid according to molecular weight, wherein low molecular weight hyaluronic acid with a molecular weight of less than 10 kDa, medium molecular weight hyaluronic acid with a molecular weight of 10 kDa or more and 100 kDa or less, and high molecular weight hyaluronic acid with a molecular weight of more than 100 kDa are each prepared at a concentration of 0.1 wt% to 3 wt%, and the remainder consists of a solvent and a stabilizer; (c2) preparing glycerin at a concentration of 3 wt% to 10 wt%, and the remainder consists of a solvent and a stabilizer; (c3) preparing butylene glycol at a concentration of 2 wt% to 8 wt%, and the remainder consists of a solvent and a stabilizer; (c4) preparing dipropylene glycol at a concentration of 1 wt% to 5 wt%, and the remainder consists of a solvent and a stabilizer; and (c5) sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline as natural moisturizing factors. The method comprises the steps of preparing each at a concentration of 0.1% to 1% by weight and the remainder composed of a solvent and a stabilizer, and (c6) mixing the moisturizing ingredients prepared in steps (c1) to (c5) at a temperature of 25°C to 35°C at a speed of 200 rpm to 400 rpm for 10 to 20 minutes, such that the total concentration of the moisturizing ingredients is 6.9% to 38% by weight and the remainder composed of a solvent and a stabilizer.

[0052] At this time, the above step (d) comprises: (d1) preparing palmitoyl pentapeptide-4, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, acetyl hexapeptide-8, copper tripeptide-1, and carnosine as peptides at a concentration of 0.001 wt% to 1 wt%, with the remainder consisting of a solvent and a stabilizer; (d2) preparing adenosine at a concentration of 0.01 wt% to 0.5 wt%, with the remainder consisting of a solvent and a stabilizer; (d3) preparing retinol derivatives such as retinol, retinyl palmitate, retinyl acetate, retinaldehydride, and retinoic acid at a concentration of 0.01 wt% to 1 wt%, with the remainder consisting of a solvent and a stabilizer; and (d4) preparing plant collagen precursors such as Centella asiatica extract, Korean red ginseng extract, green tea extract, aloe vera extract, and licorice extract. The method comprises the steps of: (d5) preparing each at a concentration of 0.1% to 5% by weight and preparing the remainder to consist of a solvent and a stabilizer; and (d5) mixing the elasticity-enhancing components prepared in steps (d1) to (d4), such that the total concentration of the elasticity-enhancing components is 0.566% to 36.5% by weight, and preparing the remainder to consist of a solvent and a stabilizer to produce an elasticity-enhancing component mixture.

[0053] At this time, the above step (e) comprises: (e1) preparing a mixing container and maintaining the temperature of the mixing container at 20°C to 30°C; (e2) first adding 10 to 40 parts by weight of the moisturizing ingredient of step (c) to the mixing container and stirring first at a speed of 100 rpm to 300 rpm for 5 to 15 minutes; (e3) adding 5 to 30 parts by weight of the hydrangea extract of step (a) to the mixing container stirred first in step (e2) by a dropwise method over 3 to 10 minutes and stirring secondly at a speed of 250 rpm to 400 rpm for 10 to 20 minutes; and (e4) adding 1 to 15 parts by weight of the peeling active ingredient of step (b) to the mixing container stirred secondly in step (e3) over 3 to 10 minutes. The method comprises the steps of: (e5) adding 1 to 20 parts by weight of the elasticity-enhancing component of step (d) by adding it by drop over 3 to 10 minutes and stirring it for 15 to 30 minutes at a speed of 250 to 400 rpm to the mixing container stirred for the third time in step (e4), and stirring it for the fourth time in 15 to 30 minutes at a speed of 250 to 400 rpm; and (e6) preparing a mixture by degassing the mixing container stirred for the fourth time in step (e5) using a vacuum degassing machine under vacuum conditions of 0.01 MPa to 0.05 MPa for 5 to 15 minutes.

[0054] At this time, the above step (f) comprises: (f1) a step of preparing an emulsifier comprising 0.3 to 3 parts by weight of cetearyl alcohol, 0.2 to 2 parts by weight of glyceryl stearate, 0.2 to 2 parts by weight of PEG-100 stearate, 0.1 to 1.5 parts by weight of sorbitan oleate, and 0.2 to 1.5 parts by weight of caprylyl / capryl glucoside as an emulsifier; (f2) a step of preparing a thickener comprising 0.05 to 1.5 parts by weight of carbomer, 0.03 to 1 part by weight of sodium acrylate / sodium acryloyl dimethyl taurate copolymer, and 0.02 to 0.5 parts by weight of polyisobutene as a thickener; and (f3) 0.3 to 2 parts by weight of 1,2-hexanediol and 0.2 to 1 part by weight of phenoxyethanol as a preservative A step of preparing a preservative to include; (f4) a step of preparing a pH adjuster to include 0.01 to 1 weight part of triethanolamine as a pH adjuster; (f5) a step of adding the emulsifier of step (f1) to the mixture of step (e) and stirring for 10 to 20 minutes at a speed of 300 rpm to 500 rpm at a temperature of 30℃ to 50℃; (f6) a step of adding the thickener of step (f2) to the stirred mixture of step (f5) and stirring for 15 to 30 minutes at a speed of 200 rpm to 400 rpm; (f7) a step of adding the preservative of step (f3) to the stirred mixture of step (f6) and stirring for 5 to 15 minutes at a speed of 150 rpm to 300 rpm; and (f8) measuring the pH of the stirred mixture of step (f7), and the measured The method comprises the step of adjusting the pH by adding the pH adjuster of step (f4) so ​​that the pH is in the range of 5.0 to 6.5, and the step of preparing a cosmetic composition by cooling the pH-adjusted mixture of step (f8) to 20°C to 30°C while stirring at a speed of 100 rpm to 200 rpm for 10 to 20 minutes.

[0055] At this time, the above step (g) comprises: (g1) a step of introducing the cosmetic composition of step (f) into a homogenizing device; (g2) a step of maintaining the temperature of the homogenizing device at 25℃ to 35℃; (g3) a step of first homogenizing the cosmetic composition using a homomixer at a speed of 3,000 rpm to 6,000 rpm for 5 minutes to 15 minutes; (g4) a step of secondarily homogenizing the cosmetic composition homogenized in step (g3) using a high shear homogenizer at a speed of 8,000 rpm to 12,000 rpm for 10 minutes to 20 minutes; and (g5) a step of thirdly homogenizing the cosmetic composition homogenized in step (g4) using a high-pressure homogenizer. A step of homogenizing by passing through 3 to 4 times repeatedly under pressure conditions of 80 bar to 150 bar, and (g6) a step of checking whether the average particle size of the cosmetic composition tertiarily homogenized in step (g5) is in the range of 0.1 μm to 5 μm by measuring by laser diffraction after ultrasonically treating with purified water as a dispersion medium for 3 minutes at a temperature of 25°C, and if it falls outside the above range, adjusting the particle size by repeating step (g5) 1 to 2 additional times, and (g7) a step of checking the viscosity of the cosmetic composition confirmed in step (g6) using a Brookfield rotational viscometer at 20°C with spindle No. The method comprises the steps of: using 5 and measuring for 1 minute at a rotational speed of 12 rpm to check if the viscosity is in the range of 10,000 cps to 25,000 cps, and if it is outside the above range, adding a thickener to adjust the viscosity; and (g8) filling the cosmetic composition confirmed in step (g7) into a container to obtain a final cosmetic composition.

[0056] The clinical paper cited in this invention is "Hydrangea serrata Hot Water Extract and Its Major Ingredient Hydrangenol Improve Skin Moisturization and Wrinkle Conditions via AP-1 and Akt / PI3K Pathway Upregulation" published by Yoon et al. (2023) in the journal Nutrients (Vol. 15, No. 2436).

[0057] The above clinical trial was conducted with a double-blind, randomized, placebo-controlled design and was carried out from October 1, 2021 to November 16, 2021, after receiving approval from the Institutional Review Board (IRB) of the Global Medical Research Center (Seoul) (Approval No.: GIRB-21929-NY, Approval Date: October 5, 2021).

[0058] The subjects were 22 healthy women aged 30 to 59 (average 49.2 years) (9 in their 40s and 12 in their 50s), selected for having dry skin and wrinkles around the eyes. The subjects applied a cream containing 0.5% Hydrangea serrata hot water extract (Hs-WE) to the left side of their face and a placebo to the right side twice daily for 4 weeks.

[0059] For the test results, skin moisture was measured using the Corneometer CM825 (Courage and Khazaka, Germany), and wrinkle depth was measured using the Antera 3D CS (Miravex, Ireland). Evaluations were conducted at time points before use (0 weeks), 2 weeks after use, and 4 weeks after use. Statistical analysis was performed using IBM SPSS Statistics 25.0 program; after testing for normality, a paired samples t-test or a Wilcoxon signed rank test was conducted.

[0060] As a result, the 0.5% Hs-WE application group showed a significant increase in skin hydration compared to the placebo group (weeks 0→weeks 4: 51.544→58.525 AU, improvement rate 13.544%, p<0.001), and wrinkle depth was significantly reduced (weeks 0→weeks 4: 0.102→0.074 mm, improvement rate 27.451%, p<0.001). Safety was also confirmed as no adverse events were reported during the study period.

[0061] In addition, through in vitro cell experiments, this paper confirmed that Hs-WE and its main component, hydrangenol, increase the expression of hyaluronic acid synthase (HAS-1, 2, 3), skin barrier factors (filaggrin, transglutaminase-1, occludin, involucrin), and collagen type I (COL1A1) in human keratinocytes (HaCaT cells), and inhibit hyaluronidase (HYAL) expression, and identified that the mechanism is achieved through the activation of AP-1 and Akt / PI3K signaling pathways.

[0062] The technical reasons, critical significance, and specific implementation methods of the above steps (a) and (a1) to (a7) are as follows.

[0063] Technical reasons for the manufacturing steps of hydrangea extract and the critical significance of the numerical range

[0064] (a1) Step: Washing and hot air drying

[0065] In this step, hot-air drying of hydrangea leaves at a temperature range of 40°C to 60°C for 12 to 24 hours has a decisive impact on the quality of the raw materials and the preservation of active ingredients. If the drying temperature is below 40°C, the drying time becomes excessively long, increasing the risk of microbial growth, and moisture removal is incomplete, leading to reduced extraction efficiency in the subsequent extraction process. On the other hand, if the temperature exceeds 60°C, the decomposition of heat-sensitive polyphenol compounds, including hydrangenol, is accelerated, resulting in a decrease in the content of active ingredients, browning of the raw materials, and volatilization of fragrance components, which degrades the quality of the final product. In particular, hydrangenol is a compound of the dihydroisocoumarin family, and exposure to excessive heat can cause oxidation and isomerization reactions.

[0066] The drying time was set to 12 to 24 hours to ensure storage stability by lowering the moisture content of hydrangea leaves to 10% or less, while optimizing energy efficiency. Drying for less than 12 hours poses a risk of microbial contamination and enzymatic decomposition due to residual moisture, while drying for more than 24 hours results in minimal additional moisture removal, increased energy consumption, and a greater risk of component degradation due to prolonged heat exposure.

[0067] (a2) Step: Add purified water

[0068] The ratio of adding 10 to 20 parts by weight of purified water to 1 part by weight of hydrangea leaf raw material is the optimal range considering both extraction efficiency and economic feasibility. If the amount of purified water is less than 10 parts by weight, the extraction solvent is insufficient, so the active ingredients inside the raw material are not completely eluted, and the solid content becomes excessively high, increasing viscosity and making it difficult to move and filter the extract. In addition, localized overheating occurs, posing a risk of component decomposition.

[0069] Conversely, if the amount of purified water exceeds 20 parts by weight, the increase in extraction efficiency is minimal, while the amount of water that must be removed in the subsequent concentration step becomes excessive, leading to increased energy consumption, longer processing time, and greater loss of components due to prolonged heat exposure during the concentration process. Additionally, the concentration of the extract becomes excessively diluted, resulting in a decrease in the yield of the final powder product. The range of 10 to 20 parts by weight is a critical range that ensures the economic viability of the process while maximizing the extraction rate of hydrangenol and other polyphenol compounds.

[0070] (a3) Step: Hot water extraction

[0071] The condition of hot water extraction at a temperature of 95°C to 100°C for 3 to 7 hours is an essential range for maximizing the extraction of water-soluble active ingredients and ensuring microbial safety. If the extraction temperature is below 95°C, the extraction efficiency of hydrangenol and other polyphenol compounds is significantly reduced, and the destruction of the cell wall structure is incomplete, preventing the sufficient extraction of active ingredients from within the cells. Furthermore, complete sterilization of microorganisms is not achieved, and thus the microbiological safety of the product cannot be ensured.

[0072] Temperatures exceeding 100℃ are difficult to achieve under normal atmospheric pressure conditions, and during pressurized extraction, excessive heat promotes the decomposition of hydrangenol and accelerates the oxidation reaction of polyphenols, resulting in a darker color of the final extract and reduced antioxidant activity. According to clinical studies, the hot water extract of hydrangea exhibited optimal efficacy when extracted at 98℃ for 5 hours, which falls within the temperature and time range of the present invention.

[0073] The extraction time range of 3 to 7 hours takes into account the minimum time required to reach extraction equilibrium of the active ingredient and the maximum time required to prevent side effects caused by excessive extraction. Extraction of less than 3 hours results in incomplete elution of hydrangenol, making it difficult to reach the content standard of 0.5% by weight of the final product, while exceeding 7 hours results in minimal additional ingredient elution effects, but also causes disadvantages such as ingredient decomposition due to prolonged heating and increased energy consumption.

[0074] (a4) Step: Membrane filtration

[0075] Using a membrane filter with a pore size of 5㎛ to 15㎛ is a critical range for effectively removing insoluble solids while minimizing the loss of active ingredients. If the pore size is less than 5㎛, the filtration speed becomes excessively slow, reducing process efficiency, and the filter clogs frequently, requiring frequent replacement, and some active ingredients may be adsorbed onto the filter, which may reduce the yield.

[0076] On the other hand, if the pore size exceeds 15㎛, fine insoluble particles pass through without being filtered, forming precipitates during subsequent concentration and drying stages or degrading the appearance of the final product. Additionally, microorganisms or spores may not be completely removed, which can reduce the microbiological safety of the product. The range of 5㎛ to 15㎛ is the optimal range that effectively removes cell wall fragments, insoluble cellulose, protein coagulants, etc., while allowing low-molecular-weight polyphenol compounds such as hydrangenol to pass through without loss.

[0077] (a5) Step: Reduced pressure concentration

[0078] Concentrating at a temperature of 60°C to 80°C under reduced pressure conditions of 0.01 to 0.1 MPa is a key condition for achieving efficient moisture removal while protecting heat-sensitive active ingredients. If the reduced pressure is less than 0.01 MPa, some volatile active ingredients may be removed along with the active ingredients due to excessive vacuum, and the increased requirements for equipment specifications reduce economic efficiency. If it exceeds 0.1 MPa, the boiling point of water is not lowered sufficiently, requiring the concentration temperature to be increased, which promotes the thermal decomposition of hydrangenol.

[0079] The concentration temperature range of 60°C to 80°C is a critical range that allows for the maintenance of hydrangenol stability while achieving efficient water evaporation under reduced pressure conditions. Below 60°C, the concentration rate is excessively slow, leading to longer process times, while above 80°C, the oxidation and degradation of polyphenol compounds are accelerated despite reduced pressure conditions. Considering the preparation methods for hydrangea extracts reported in clinical papers, this temperature range is essential for maintaining the hydrangenol content at 0.5 to 2.0 wt%.

[0080] (a6) Step: Freeze-drying or spray-drying

[0081] In the case of freeze-drying, processing at -80°C for at least 48 hours is an essential condition to ensure the complete freezing and sublimation drying of the concentrate. Temperatures below -80°C are difficult to achieve with conventional freeze-drying equipment and result in excessive energy consumption; at temperatures higher than -80°C, the concentrate does not freeze completely, leading to melting instead of sublimation drying, which can cause the product's structure to collapse. Processing for less than 48 hours leaves residual moisture, reducing the storage stability of the product and causing microbial growth and chemical decomposition reactions.

[0082] In the case of spray drying, conditions of an inlet temperature of 150°C to 180°C and an outlet temperature of 80°C to 100°C are the optimal range for achieving complete drying while minimizing thermal damage through instantaneous drying. If the inlet temperature is below 150°C, the drying of the droplets is incomplete, resulting in the powder being recovered in a wet state and aggregation between particles. If the temperature exceeds 180°C, casing occurs due to rapid drying of the particle surface, trapping internal moisture and potentially causing some hydrangenol to decompose by heat.

[0083] If the outlet temperature is below 80℃, the moisture content of the powder is high, causing caking during storage and posing a risk of microbial growth; if it exceeds 100℃, excessive drying causes the powder to become excessively fine, making it difficult to handle and increasing hygroscopicity. This temperature range is a critical condition that minimizes the loss of hydrangenol content while maintaining the moisture content of the powder at 5% or less.

[0084] (a7) Step: Hydranzenol content analysis

[0085] Setting the hydrangenol content to 0.5% by weight to 2.0% by weight is an essential range for simultaneously achieving clinical efficacy and standardization of the raw material. According to clinical papers, hydrangenol is a key indicator component of hydran extract, and this compound activates the AP-1 and Akt / PI3K pathways to increase the expression of hyaluronic acid synthase, thereby exhibiting skin moisturizing and wrinkle improvement effects. At a content of less than 0.5% by weight, these physiological effects are not significantly observed, and when exceeding 2.0% by weight, the additional increase in efficacy is minimal, while the cost of the raw material increases and there is a possibility of causing irritation in some sensitive skin.

[0086] The use of a C18 column and a detection wavelength of 280 nm in HPLC analysis is based on the chemical structural characteristics of hydrangenol. Hydrangenol possesses an aromatic ring structure and exhibits maximum absorbance at 280 nm, and the C18 reverse-phase column provides excellent separation capabilities due to the appropriate hydrophobic properties of this compound. The acetonitrile and water gradient solvent system effectively separates hydrangenol from other polyphenol compounds, enabling accurate quantitative analysis.

[0087] The electrospray ionization mode of LC-MS / MS is utilized as a confirmatory analysis method that complements HPLC, as it can confirm the molecular weight and structure of hydrangenol and detect even trace amounts of compounds with high sensitivity. The calibration curve method using standards guarantees the accuracy and reproducibility of quantitative analysis and is essential for ensuring quality consistency between batches.

[0088] Specific implementation methods for each step

[0089] (a1) Specific implementation method of step

[0090] Hydrangea leaves are first washed under running tap water to remove surface soil, dust, and foreign substances. Subsequently, a second wash is performed with purified water to completely remove residual impurities and water-soluble contaminants. After washing, the hydrangea leaves are dried using a sieve or a spin dryer to remove surface moisture before being fed into the drying process. Since excessive surface moisture increases energy consumption and prolongs drying time during the initial stages, it is desirable to remove it as much as possible.

[0091] A circulating hot air dryer capable of maintaining a uniform internal temperature is used, and the temperature is reached at a set level of 40°C to 60°C through preheating before drying. Hydrangea leaves are spread out in a single layer on the dryer trays without overlapping, and sufficient spacing is ensured between trays to facilitate smooth hot air circulation. During drying, the trays are rotated every two hours to ensure uniform drying.

[0092] The drying temperature is monitored by installing temperature sensors at various points inside the dryer, ensuring that the temperature deviation is maintained within ±2℃. The drying time is adjusted within a range of 12 to 24 hours depending on the initial moisture content of the raw material, leaf thickness, and loading amount. The completion of drying is confirmed by the degree to which the leaves crumble when touched and by measuring the moisture content using a moisture meter; drying is terminated when the final moisture content reaches 10% or less. The dried hydrangea leaves are placed in an airtight container and stored in a cool place away from direct sunlight, and are introduced into the extraction process as soon as possible.

[0093] (a2) Specific implementation method of step

[0094] The dried hydrangea leaf raw material is weighed to determine the exact weight before being placed in the extraction container. Large leaves can be cut into appropriate sizes to increase extraction efficiency; generally, cutting them to a size of 2 cm to 5 cm is appropriate. Excessive grinding should be avoided, as it makes filtration of the extract difficult and causes suspension of fine particles.

[0095] Purified water is water with a purity of 10 μS / cm or less and a total organic carbon of 500 ppb or less. Room temperature or lukewarm water may be used considering extraction efficiency, and excessively cold water prolongs the time required to reach the extraction temperature. The ratio of 10 to 20 parts by weight of purified water to 1 part by weight of hydrangea leaf raw material is determined considering the absorption characteristics of the raw material and extraction efficiency.

[0096] The extraction vessel uses a stainless steel extractor and is equipped with an internal stirring device to ensure uniform contact between the raw material and the solvent during extraction. After adding the raw material and purified water, stirring is performed to ensure the raw material is completely immersed in the purified water; if the raw material floats on the water surface, additional purified water is added or a mesh net is used to submerge the raw material. Allowing a preliminary immersion time of 30 minutes to 1 hour at room temperature after addition hydrates the cell walls of the raw material, thereby increasing the efficiency of the subsequent hot water extraction.

[0097] (a3) Specific implementation method of step

[0098] The extraction vessel is heated to raise the internal temperature to 95°C to 100°C. An electric heater, steam jacket, or direct flame heating method may be used, and a method with excellent accuracy and uniformity of temperature control is selected. The rate of temperature increase is controlled to 2°C to 5°C per minute to prevent loss of components or entrainment of droplets due to rapid temperature changes.

[0099] After reaching the set temperature, extraction is carried out for 3 to 7 hours while maintaining that temperature. During extraction, a stirrer is operated to stir gently at a speed of 50 to 100 revolutions per minute. Excessive stirring should be avoided, as it causes foaming of the extract and dispersion of fine particles. A reflux condenser is installed in the extraction vessel to prevent water vapor from escaping and to maintain a constant amount of solvent.

[0100] The extraction temperature is monitored in real time via a thermometer or temperature sensor installed inside the container, and the heating intensity is adjusted to ensure the temperature does not exceed the set range. The extraction time is determined within the range of 3 to 7 hours, taking into account the type of raw material, particle size, and extraction temperature; generally, optimal results are obtained with a 5-hour extraction. Once extraction is complete, heating is stopped, and the process is waited until the temperature of the extract drops below 80℃ before being transferred to the filtration process.

[0101] (a4) Specific implementation method of step

[0102] The extract first undergoes a coarse filtration stage to remove large solids. For coarse filtration, a stainless steel mesh or non-woven fabric filter is used, and a mesh size of 100 to 200 mesh is suitable. By removing leaf fragments, large fibers, etc. through coarse filtration, the load on subsequent fine filtration is reduced.

[0103] Microfiltration uses a membrane filter with a pore size of 5㎛ to 15㎛. The membrane filter material may be cellulose acetate, polyethersulfone, nylon, etc., and is selected considering chemical stability and filtration efficiency. Gravity filtration, pressurized filtration, or vacuum filtration may be used, and pressurized filtration applying a pressure of 0.1 to 0.3 MPa is generally efficient.

[0104] Before filtration, the membrane filter is washed with purified water to remove preservatives or impurities, and the filter is stabilized by performing preliminary filtration with a small amount of extract. If the filtration rate decreases, it indicates clogging of the filter, so it should be replaced with a new filter. The filtered liquid must be clear and transparent, and no suspended particles or sediment should be observed.

[0105] To increase the yield of the filtrate, the solids remaining in the filter can be washed with a small amount of purified water to recover the residual extract. At this time, the amount of washing water is limited to within 10% of the total extract to prevent excessive dilution of the filtrate. The filtered filtrate is placed in a stainless steel container, protected from direct sunlight, and transferred to the concentration process as quickly as possible.

[0106] (a5) Specific implementation method of step

[0107] The filtrate is fed into a vacuum concentrator. The vacuum concentrator consists of a vacuum pump, a heating device, a reflux cooler, and a condenser, and utilizes equipment capable of precisely controlling temperature and pressure. The vacuum pump is operated to lower the pressure inside the concentrator to 0.01 to 0.1 MPa. Pressure is monitored in real-time via a vacuum gauge, and heating begins when the set pressure is reached.

[0108] Heating is controlled so that the temperature of the filtrate reaches 60°C to 80°C. Within this temperature range, water evaporates efficiently due to reduced pressure conditions, and the decomposition of heat-sensitive components, including hydranzenol, is minimized. A water bath or mantle heater is used for heating, and a method with precise temperature control is selected. During concentration, in the case of a rotary evaporator, the flask is rotated at a speed of 30 to 60 revolutions per minute to increase the surface area of ​​the liquid and improve evaporation efficiency.

[0109] The evaporated water vapor passes through a cooler, condenses, and is collected in a separate collection container. Concentration proceeds until the volume of the filtrate is reduced to 1 / 5 to 1 / 10 of the initial volume, and the concentration is terminated when the solid content of the concentrate reaches 20% to 40%. Excessive concentration increases viscosity excessively, making handling difficult during the subsequent drying process, and poses a risk of component decomposition due to localized overheating.

[0110] Once concentration is complete, the vacuum is slowly released to recover the concentrate. The concentrate is a viscous liquid ranging from dark brown to blackish-brown in color with a distinctive odor. The recovered concentrate is placed in a sealed container and stored under refrigerated conditions at 4°C or below; it is transferred to a drying process within 24 hours if possible. Prompt processing is required because prolonged storage poses a risk of microbial growth or component degradation.

[0111] (a6) Specific implementation method of step

[0112] If freeze-drying is selected, spread the concentrate thinly in a suitable container or tray. A liquid thickness of 5mm to 10mm is appropriate; an excessively thick layer prolongs the freezing and drying time. Place the container holding the concentrate on a shelf of the freeze-dryer, seal the chamber, and start the freezing stage.

[0113] In the freezing stage, the temperature of the shelf is lowered to -80°C to completely freeze the concentrate. The freezing time varies depending on the amount and thickness of the concentrate, but generally takes 4 to 8 hours. Once the concentrate is completely frozen, a vacuum pump is activated to lower the pressure inside the chamber to 0.01 to 0.1 Pa. Subsequently, a sublimation drying stage is performed, during which the frozen moisture is removed by sublimating directly into a gas without passing through a liquid state.

[0114] Sublimation drying is carried out for at least 48 hours, and may take more than 72 hours if the sample volume is large. During drying, the temperature of the shelf can be gradually increased to -40°C to -20°C to optimize the sublimation rate. Whether drying is complete is determined by monitoring changes in pressure inside the chamber, the moisture collection rate of the condenser, and the temperature of the sample. Once drying is complete, the vacuum is gradually released and the dried powder is recovered.

[0115] When selecting spray drying, the concentrate is fed into the hopper of the spray dryer. If the viscosity of the concentrate is high, a small amount of purified water can be added to adjust the viscosity and increase the spraying efficiency. The inlet temperature of the spray dryer is set to 150°C to 180°C, and the inside of the drying chamber is preheated by operating a hot air generator.

[0116] The concentrate is supplied to a nozzle through a high-pressure pump and sprayed as fine droplets from the nozzle. The pressure of the nozzle is controlled to 10 to 30 MPa, and the droplet size is set to 20 µm to 50 µm. The sprayed droplets are instantaneously dried by contact with high-temperature hot air, and the outlet temperature is maintained at 80°C to 100°C. The dried powder is separated from the air and recovered through a cyclone separator, and the fine powder is further collected through a bag filter.

[0117] During spray drying, the inlet temperature, outlet temperature, feed rate, and hot air flow rate are continuously monitored and controlled to produce powder of consistent quality. The recovered powder is immediately placed in a sealed container to prevent moisture absorption, and the moisture content of the powder is confirmed to be 5% or less. Both drying methods ultimately yield a fine light brown to brown powder, which is hydrangea extract powder.

[0118] (a7) Specific implementation method of step

[0119] To quantitatively analyze the hydrangenol content in hydrangea extract powder, a standard substance is first prepared. Reagent-grade hydrangenol standard substance with a purity of 95% or higher is used, and a 1 mg / mL standard solution is prepared by dissolving it in methanol or ethanol. This is sequentially diluted to prepare standard solutions for calibration curves at concentrations of 0.01, 0.05, 0.1, 0.5, and 1.0 mg / mL.

[0120] For the sample solution, accurately weigh 100 mg of hydrangea extract powder and place it in a 50 mL volumetric flask. Add 40 mL of methanol or ethanol and extract using an ultrasonic extractor for 30 minutes. After cooling to room temperature, fill to the mark with methanol or ethanol and mix thoroughly. Filter this solution through a 0.45 µm or 0.22 µm syringe filter to prepare a sample solution for HPLC analysis.

[0121] The HPLC analysis conditions are as follows. A C18 reverse-phase column is used, and generally, specifications of 4.6 mm × 250 mm with a particle size of 5 µm are suitable. Acetonitrile and water are used as the mobile phase via a gradient elution method. The gradient program typically starts with an initial 10% acetonitrile and increases linearly to 80% over 30 minutes. The flow rate is set to 1.0 mL / min, and the column temperature is maintained at 30°C.

[0122] A UV detector is used, and the detection wavelength is set to 280 nm. This wavelength corresponds to the maximum absorption wavelength of hydrangenol and provides optimal sensitivity. The injection volume for both the standard solution and the sample solution is set to 10 µl. A chromatogram is obtained by sequentially injecting the standard solution, and a calibration curve is constructed from the relationship between the area of ​​the hydrangenol peak and the concentration. The correlation coefficient of the calibration curve must be 0.999 or higher.

[0123] A chromatogram is obtained by injecting the sample solution, and the hydrangenol peak is identified. The retention time of hydrangenol generally appears in the range of 15 to 20 minutes. The identification of the peak is confirmed by comparing it with the retention time of a standard substance, and if necessary, it can be confirmed by switching the detector to a PDA (Photodiode Array Detector) and comparing the UV spectra. The concentration is calculated by substituting the hydrangenol peak area of ​​the sample solution into the calibration curve, and the hydrangenol content in the hydrangea extract powder is calculated as a percentage by considering the dilution factor.

[0124] When performing LC-MS / MS analysis, samples are prepared and separated using the same method as for HPLC, and then detected by a mass spectrometer. Electrospray ionization is used, and either positive or negative mode can be selected. Since the molecular weight of hydrangenol is 290, [M+H]+ or [MH]- ions are monitored. In MS / MS mode, specific precursor ions are selected, and product ions generated through collision-induced dissociation are detected to enhance selectivity and sensitivity.

[0125] For quantitative analysis using LC-MS / MS, the method of constructing a calibration curve using standard substances and calculating the content from the peak area of ​​the sample is the same. Finally, it is confirmed that the hydrangenol content of the hydrangea extract powder is within the range of 0.5 wt% to 2.0 wt%; if it falls outside this range, the extraction or drying conditions are reviewed to optimize the process. The analysis is repeated at least three times to obtain the mean value and standard deviation, and the reproducibility of the analysis results is determined to be secured when the relative standard deviation is within 3%.

[0126] The technical reasons, critical significance, and specific implementation methods of the above steps (b) and (b1) to (b5) are as follows.

[0127] Technical reasons for the preparation step of peeling active ingredients and critical significance of the numerical range

[0128] (b1) Step: Technical Significance of AHA Ingredients

[0129] The complex combination of glycolic acid, lactic acid, mandelic acid, and citric acid in this step is intended to achieve a low-irritation yet effective peeling effect by utilizing the different molecular weights and skin penetration characteristics of each ingredient. Glycolic acid has a molecular weight of 76, the smallest among AHAs, allowing for excellent skin penetration. It effectively weakens the bonds between keratinocytes in the epidermal layer, resulting in superior exfoliation. However, due to its small molecular weight and rapid penetration speed, there is also a higher potential for skin irritation.

[0130] Limiting the concentration of glycolic acid to 0.1 to 1.0 weight percent is a key strategy for achieving low-irritation peeling. While general peeling products use 5 to 10 weight percent or more of glycolic acid, this causes side effects such as severe irritation, redness, and stinging, making daily use impossible. Below 0.1 weight percent, the exfoliating effect is negligible, failing to adequately perform the peeling function, while exceeding 1.0 weight percent can lead to accumulated skin irritation and damage to the skin barrier during daily use. The range of 0.1 to 1.0 weight percent is a critical range that minimizes irritation while providing a sufficient peeling effect through synergistic effects with other AHA ingredients.

[0131] Lactic acid has a molecular weight of 90, which is greater than that of glycolic acid, and is characterized by providing both exfoliating and moisturizing effects simultaneously. As one of the skin's natural moisturizing factors, lactic acid improves the moisture retention capacity of the stratum corneum and prevents skin dryness that may occur during the peeling process. The concentration of lactic acid is set to 0.1 to 0.8 weight% to achieve a balance between peeling and moisturizing. Below 0.1 weight%, the moisturizing effect is negligible, and above 0.8 weight%, the pH becomes excessively low, which may increase skin irritation.

[0132] Mandelic acid has the largest molecular weight among AHAs with 152, and exhibits the mildest peeling effect due to its slow skin penetration rate. Additionally, mandelic acid possesses lipophilic properties, allowing it to penetrate into the sebaceous glands to prevent acne, and antibacterial activity has also been reported. The concentration of mandelic acid is set to 0.1 to 0.7 weight%, which is a range that allows for safe use even on sensitive skin. Below 0.1 weight%, the peeling effect is insufficient, and above 0.7 weight%, the total acid concentration may become excessive due to aggregation with other AHA ingredients.

[0133] Citric acid is a tricarboxylic acid with a molecular weight of 192 and a triple carboxyl group, primarily functioning as a pH regulator and chelating agent. Although citric acid has a relatively weak exfoliating effect, it improves product stability by chelating metal ions and plays a role in adjusting the pH of the peeling active ingredient mixture to an optimal range. The concentration of citric acid is limited to 0.1 to 0.5 weight% to prevent excessive acidification while performing the pH-regulating function. Below 0.1 weight%, the pH-regulating effect is insufficient, and above 0.5 weight%, the pH of the product becomes excessively low, leading to increased skin irritation.

[0134] (b2) Step: Technical Significance of BHA Ingredients

[0135] Salicylic acid is a fat-soluble hydroxy acid with a unique mechanism of removing dead skin cells by dissolving the intercellular binding substances composed of sebum and lipids. Unlike water-soluble AHAs, BHAs penetrate deep into the pores to dissolve sebum plugs and effectively keep the pores clean. Additionally, salicylic acid has anti-inflammatory effects, which suppress micro-inflammation that may occur during the peeling process.

[0136] The concentration of salicylic acid was set to 0.1 to 2 weight percent to simultaneously consider the usage limit in cosmetics and the purpose of low-irritation peeling. The domestic Cosmetics Act limits the maximum usage concentration of salicylic acid to 2 weight percent, which is a range where safety is ensured. Below 0.1 weight percent, the pore cleansing and exfoliation effects are negligible, and exceeding 2 weight percent not only violates legal regulations but may also lead to excessive skin irritation, dryness, and peeling.

[0137] Salicylic acid derivatives include beta-hydroxybutanoic acid, tropolone, and beta-hydroxycapryloyl salicylic acid, which exhibit a milder peeling effect than salicylic acid while causing less skin irritation. Even when using derivatives, the same concentration range is applied to ensure safety. BHA components work complementarily with AHA components; while AHA removes dead skin cells from the surface of the epidermis, BHA removes dead skin cells and sebum from inside the pores, thereby achieving a three-dimensional peeling effect.

[0138] (b3) Step: Technical Significance of PHA Components

[0139] Polyhydroxy acids are known as next-generation peeling ingredients; due to their large molecular weight and numerous hydroxyl groups, they are characterized by slow skin penetration and very low irritation. Gluconolactone has a molecular weight of 178 and possesses a lactone ring structure; it exhibits a gentle peeling effect as it slowly hydrolyzes in the skin and converts into gluconic acid. Lactobionic acid has a molecular weight of 358 and possesses a disaccharide structure; due to its even larger molecular weight compared to gluconolactone, it causes almost no irritation and provides a powerful moisturizing effect.

[0140] The concentration of the PHA component is set to 0.5 to 3 weight% to achieve sufficient exfoliation and moisturizing effects while implementing a low-irritation peeling effect. Below 0.5 weight%, the peeling effect is negligible and the buffering effect to alleviate irritation from AHA and BHA is insufficient, and above 3 weight%, the viscosity increases excessively, which degrades the usability of the formulation and reduces economic efficiency due to high raw material costs.

[0141] Although PHA has a slower skin penetration rate compared to AHA or BHA, it has an excellent humectant effect that attracts moisture from the skin surface, effectively preventing skin dryness that occurs during the peeling process. In addition, PHA has an antioxidant effect, which reduces oxidative stress on the skin after peeling, and improves product stability through its metal ion chelating function. In the present invention, one or both of gluconolactone and lactobionic acid may be used in combination, and when used in combination, the sum of their respective concentrations is adjusted to be 0.5 to 3 weight%.

[0142] (b4) Step: Technical Significance of Enzyme Peeling Agents

[0143] Enzyme peeling agents operate through a completely different mechanism from acidic chemical peeling agents. Proteolytic enzymes remove dead skin cells by specifically hydrolyzing the peptide bonds of keratin proteins that constitute keratinocytes; since they function independently of pH or irritation, they can be safely used even on sensitive skin. Papain is a cysteine ​​protease extracted from papaya that possesses broad substrate specificity and has the characteristic of selectively degrading dead skin cells without affecting living cells.

[0144] The concentration of papain is set to 0.02 to 0.3 weight%, a range that takes into account enzyme activity and stability. Below 0.02 weight%, the amount of enzyme is insufficient, resulting in a negligible exfoliation effect; above 0.3 weight%, excessive protein degradation may cause skin irritation and drastically increase raw material costs. Papain exhibits optimal activity at pH 5.0 to 7.0, which matches the pH range of the peeling active ingredient mixture of the present invention.

[0145] Bromelain is a cysteine ​​protease extracted from pineapple stems that has a mechanism of action similar to papain, but has slightly different substrate specificity. The concentration of bromelain was set to 0.02 to 0.25 weight% to account for the complementary effect with papain. Using the two enzymes together allows for the degradation of a wider range of protein substrates, thereby enhancing the peeling effect.

[0146] Pumpkin enzyme is an enzyme complex extracted from pumpkin that contains various hydrolytic enzymes in addition to protease. Pumpkin enzyme exhibits skin soothing and antioxidant effects along with exfoliation effects, and promotes skin regeneration by containing trace nutrients such as vitamin A precursors and zinc. The concentration of pumpkin enzyme is set to 0.02 to 0.25 weight% to achieve a balance between peeling and skin soothing effects.

[0147] Pineapple enzyme has an enzyme profile similar to, but slightly different from, bromelain extracted from pineapple pulp. The concentration of pineapple enzyme was set to 0.02 to 0.2 weight%, which is the range that exhibits the optimal peeling effect when combined with other enzymes. The use of four enzymes in combination is intended to produce a synergistic effect by allowing each enzyme to cleave different peptide bonds, thereby achieving a more uniform and smoother peeling effect than when using a single enzyme.

[0148] The lower limit concentration of the enzyme peeling agent is set to 0.02% by weight, taking into account the minimum effective concentration of the enzyme, and the upper limit concentration is set differentially to 0.2 to 0.3% by weight according to the characteristics of each enzyme to prevent excessive protein degradation. Unlike acidic ingredients, enzyme peeling agents do not cause irritation due to pH and can achieve effective exfoliation without damaging the skin barrier, making them a key ingredient in low-irritation peeling products suitable for daily use.

[0149] (b5) Step: Set the total concentration of the peeling active ingredient

[0150] Setting the total concentration of the peeling active ingredients to 1.08 to 9 weight% represents a critical range that finds a balance between low-irritation peeling and effective exfoliation. The total concentration of 1.08 weight% is the sum of the minimum concentrations of each ingredient; adding 0.1% glycolic acid, 0.1% lactic acid, 0.1% mandelic acid, 0.1% citric acid, 0.1% salicylic acid, 0.5% gluconolactone, 0.02% papain, 0.02% bromelain, 0.02% pumpkin enzyme, and 0.02% pineapple enzyme results in 1.08%. Even at this concentration, the four classes of peeling ingredients work together to exhibit a significant exfoliating effect.

[0151] If the total concentration is less than 1.08% by weight, the peeling effect is too weak, so dead skin cells are not sufficiently removed despite daily use, and no noticeable skin improvement effect is observed by the consumer. On the other hand, a total concentration of 9% by weight is an upper limit achieved by appropriately combining the maximum concentrations of each ingredient; exceeding this limit deviates from the concept of low-irritation peeling, causing irritation similar to that of typical high-concentration peeling products. In particular, daily use can damage the skin barrier and cause redness, stinging, and peeling, while long-term use may thin the skin and make it sensitive.

[0152] The range of 1.08 to 9 weight percent is the golden ratio in which the four peeling mechanisms of AHA, BHA, PHA, and enzymes work complementarily to achieve a more effective and safer peel than using each one individually at high concentrations. As reported in clinical papers, low-irritation peeling products simultaneously improve skin hydration and elasticity, because they normalize the turnover of the stratum corneum and enhance the penetration of active ingredients without damaging the skin barrier caused by excessive peeling.

[0153] Specific implementation methods for each step

[0154] (b1) Specific implementation method of step

[0155] Glycolic acid is used in the form of an aqueous solution with a reagent-grade purity of 70% or higher, and is weighed to achieve a final concentration of 0.1 to 1.0 wt%, taking purity into account. For example, to use a 70% aqueous glycolic acid solution to ensure the final product contains 0.5 wt% glycolic acid, 0.5 ÷ 0.7 = 0.714 wt% of the aqueous glycolic acid solution is added. Since glycolic acid is a strong acid, protective gloves and safety glasses must be worn when handling it, and care must be taken to avoid contact with skin or eyes.

[0156] Lactic acid with a reagent-grade purity of 85% or higher should be used. Since L-lactic acid exhibits superior skin affinity among the optical isomers, it should be used whenever possible. Lactic acid should be weighed to achieve a final concentration of 0.1 to 0.8 weight% and added based on an 85% aqueous lactic acid solution. As lactic acid is highly hygroscopic, it should be stored in a sealed container and used promptly after opening.

[0157] Reagent-grade mandelic acid with a purity of 98% or higher, supplied in powder form, is used. Since mandelic acid has relatively low solubility in water, a method is used in which it is first dissolved in a small amount of ethanol or propylene glycol and then diluted by adding purified water. The amount is calculated and added so that the final concentration of mandelic acid is 0.1 to 0.7 weight%. As crystals may precipitate from the mandelic acid solution at room temperature, it is heated to 40°C to 50°C to ensure complete dissolution before use.

[0158] Citric acid is used in the form of anhydrous or monohydrate powder, and food additive or reagent grade with a purity of 99% or higher is used. Since citric acid has high solubility in water, it can be used by dissolving it directly in purified water. Citric acid is weighed so that the final concentration is 0.1 to 0.5 weight%, and the amount is accurately converted by taking into account the difference in molecular weight between the anhydrous and monohydrate forms.

[0159] The four AHA ingredients are dissolved in separate containers and then mixed. Purified water is mainly used as the solvent, and ethanol, propylene glycol, butylene glycol, etc., may be used as auxiliary solvents if necessary. 0.01 to 0.1 weight% of EDTA or its salt is added as a stabilizer to prevent oxidation by metal ions, and if necessary, 0.01 to 0.05 weight% of the antioxidant tocopherol or ascorbyl palmitate is added.

[0160] The pH of the mixed AHA solution is measured and is generally in the range of 2.5 to 4.0. If the pH is excessively low, a small amount of aqueous sodium hydroxide solution or triethanolamine is added dropwise to adjust the pH to 3.0 to 3.5. If the pH is excessively high, the peeling effect is reduced, so the AHA component is added to adjust it. Finally, the AHA mixed solution is transparent and colorless to pale yellow; it is then placed in a sealed container and stored in a cool, dark place.

[0161] (b2) Specific implementation method of step

[0162] Reagent-grade salicylic acid with a purity of 99% or higher is used in powder form. Since salicylic acid has low solubility in water, a method is used in which it is first dissolved in ethanol and then purified water is added. Specifically, salicylic acid powder is dissolved in ethanol equivalent to twice the target concentration, and after complete dissolution, an equal amount of purified water is added so that the final concentration becomes 0.1 to 2 weight%. The stability and solubility of salicylic acid are maintained by adjusting the ethanol concentration to 5 to 10 weight% in the final product.

[0163] When using salicylic acid derivatives, beta-hydroxybutanoic acid can be prepared directly as an aqueous solution because its solubility in water is higher than that of salicylic acid. Since beta-hydroxycapryloyl salicylic acid is fat-soluble, it is dissolved in the oil phase and then mixed with the aqueous phase through an emulsification process. Each derivative is used by converting it to a concentration that exhibits equivalent efficacy to salicylic acid, and generally, derivatives show similar effects at concentrations 1.5 to 2 times higher than salicylic acid.

[0164] 0.01 to 0.05 weight% of butylhydroxytoluene or butylhydroxyanisole is added to the BHA solution as a stabilizer to prevent oxidation. Additionally, adding 0.1 to 0.5 weight% of polysorbate 20 or 80 as a solubilizing agent improves the solubility of salicylic acid and the transparency of the formulation. The pH of the BHA solution is generally in the range of 3.5 to 4.5, and if necessary, it is adjusted to pH 4.0 using citric acid or sodium citrate buffer.

[0165] Since salicylic acid is susceptible to photodegradation, store it in a brown glass bottle and avoid direct sunlight. Additionally, as salicylic acid can decompose into phenol through decarboxylation at high temperatures, store it in a cool, dark place at 25°C or below. The prepared BHA solution should be transparent, colorless to pale yellow, and free from precipitation or turbidity. If crystals precipitate, heat the solution to 40°C to 50°C to re-dissolve them before use.

[0166] (b3) Specific implementation method of step

[0167] Gluconolactone is used in powder form with a purity of 98% or higher. Since gluconolactone has very high solubility in water and dissolves easily even at room temperature, it can be used by dissolving it directly in purified water. Gluconolactone is weighed to achieve a final concentration of 0.5 to 3 weight% and added to purified water, and then completely dissolved by stirring with a magnetic stirrer at 20 to 30°C for 10 to 20 minutes.

[0168] Lactobionic acid is supplied in powder or syrup form, and in the case of powder, a product with a purity of 95% or higher is used. Since lactobionic acid forms a highly viscous solution due to its disaccharide structure, stirring conditions are adjusted considering the concentration. Lactobionic acid is weighed to achieve a final concentration of 0.5 to 3 weight% and added to purified water, and stirred for 30 to 60 minutes while heating to 40 to 50°C to completely dissolve it.

[0169] When gluconolactone and lactobionic acid are used in combination, the concentrations of each are adjusted to a total of 0.5 to 3 weight%. Generally, mixing 0.3 to 1.5 weight% of gluconolactone and 0.2 to 1.5 weight% of lactobionic acid can achieve an optimal balance of peeling and moisturizing effects. The two ingredients can be dissolved separately and then mixed, or they can be added to purified water simultaneously and dissolved.

[0170] 0.01 to 0.1 weight percent of EDTA is added to the PHA solution as a stabilizer to prevent decomposition by metal ions. In addition, a small amount of sodium citrate or phosphate buffer may be added to stabilize the pH. The pH of the PHA solution is generally in the range of 4.5 to 6.0, and if necessary, sodium hydroxide or citric acid is used to adjust the pH to 5.0 to 5.5.

[0171] Since gluconolactone slowly hydrolyzes into gluconic acid in aqueous solution, it is best to use it as soon as possible after preparation. If long-term storage is required, adjusting the pH to 5.5 to 6.0 and refrigerating the product improves stability. Although lactobionic acid is more stable than gluconolactone, it can undergo caramelization at high temperatures, so it should be stored at 25°C or below. The PHA solution is clear, colorless, and has slight viscosity.

[0172] (b4) Specific implementation method of step

[0173] Papain is used in the form of crude enzyme powder or purified enzyme powder extracted from papaya latex. Since papain activity varies by product, check the enzyme activity unit; generally, use a product with an activity of 2,000 to 6,000 USP unit / mg. Dissolve papain in water, using cold or lukewarm water to maintain enzyme activity. Add papain powder to purified water at 10°C to 25°C and dissolve by gently stirring. Exercise caution, as excessive stirring or foaming can cause enzyme denaturation.

[0174] Papain is weighed to a final concentration of 0.02 to 0.3 weight% and adjusted considering enzyme activity. For example, when using papain with 4000 USP unit / mg activity, adding 0.1 weight% results in an enzyme activity of 4 USP unit / g in the final product. L-cysteine ​​or reduced glutathione is added to the papain solution at a concentration of 0.01 to 0.05 weight% as an enzyme stabilizer to prevent oxidation of the cysteine ​​residue, which is the active site of the enzyme.

[0175] Bromelain is used as an enzyme powder extracted from pineapple stems, and its activity is generally 1,000 to 3,000 GDU / g. Bromelain is dissolved in cold or lukewarm water in the same way as papain and weighed to a final concentration of 0.02 to 0.25 weight%. Since bromelain has a wider pH stability range than papain and maintains activity at pH 4.0 to 8.0, pH adjustment of the formulation is relatively easy.

[0176] Pumpkin enzyme is used as an enzyme complex extracted from pumpkin flesh or seeds. Since the pumpkin enzyme is supplied in the form of a complex extract containing various enzymes and nutrients, the pure enzyme content is checked and adjusted so that the final concentration is 0.02 to 0.25 weight%. As the pumpkin enzyme also contains fat-soluble components, a small amount of emulsifier is used to disperse it in the aqueous phase.

[0177] The pineapple enzyme used is an enzyme extracted from pineapple pulp, and its activity is 500 to 2000 CDU / g. The pineapple enzyme is weighed and dissolved in cold water so that the final concentration is 0.02 to 0.2 weight%. The four enzymes can be dissolved in separate containers and then mixed, or they can be added sequentially to the same container and dissolved.

[0178] The pH of the enzyme mixture solution is adjusted to 5.0 to 6.0 to ensure that all enzymes exhibit optimal activity. Sodium citrate buffer or phosphate buffer is used as a pH adjuster; strong acids or strong bases are not used as they can denature the enzymes. To prevent microbial contamination, 0.5 to 1.0 wt% of phenoxyethanol or 0.5 to 1.0 wt% of 1,2-hexanediol is added to the enzyme solution as a preservative. Common paraben preservatives are avoided as they can be degraded by enzymes.

[0179] The enzyme solution is clear to slightly cloudy, colorless, or pale yellow. Due to its low stability at room temperature, it should be refrigerated immediately after preparation or mixed into the final product. Since enzyme activity may decrease with long-term storage, it is recommended to use the solution within one week of preparation. While freezing can maintain enzyme activity for a longer period, repeated freezing and thawing should be avoided, as some enzymes may be denatured during the process.

[0180] (b5) Specific implementation method of step

[0181] A low-irritation peeling active ingredient mixture is prepared by mixing the AHA solution, BHA solution, PHA solution, and enzyme solution prepared in steps (b1) to (b4). Mixing is carried out in a large stainless steel mixing vessel, which is washed with purified water beforehand, disinfected with 70% ethanol, and then dried. The mixing vessel must be equipped with a stirring device and a temperature control device.

[0182] The mixing order is to first add the PHA solution to the container, followed by the sequential addition of the AHA solution, BHA solution, and enzyme solution. This order is intended to moderate pH changes and prevent rapid pH exposure of the enzyme. Since PHA is relatively weakly acidic and has buffering capabilities, adding it first can mitigate the pH shock of the subsequent components. After adding each solution, the mixture is uniformly mixed by stirring at a speed of 100 to 200 rpm for 5 to 10 minutes.

[0183] During mixing, the temperature is maintained at 20°C to 25°C to preserve the activity of the enzymes. If the temperature exceeds 30°C, the activity of some enzymes begins to decrease, so a cooling device is operated if necessary. After adding all four solutions, a final stirring is performed at a speed of 200 to 300 rpm for 15 to 30 minutes to prepare a completely homogeneous mixture.

[0184] The total concentration of the peeling active ingredient in the mixture is calculated and checked to see if it falls within the range of 1.08 to 9 weight%. If the concentration is higher than the target range, it is diluted by adding purified water; if it is lower, it is adjusted by adding the missing ingredient. The remaining components, namely the solvent and stabilizer, consist of solvents such as purified water, ethanol, butylene glycol, and propylene glycol, and stabilizers such as EDTA, antioxidants, and preservatives.

[0185] Measure the pH of the mixture and adjust the final pH to a range of 4.5 to 5.5. This pH range is the optimal range for preserving enzyme activity and minimizing skin irritation while maintaining the peeling effects of AHA and BHA. If the pH is below 4.5, add a small amount of triethanolamine or arginine aqueous solution dropwise to raise the pH; if it exceeds 5.5, add an aqueous citric acid solution dropwise to lower the pH. When adjusting the pH, do not add an excess amount at once, but add small amounts dropwise while monitoring the pH.

[0186] The final mixture is transparent to slightly cloudy pale yellow in color and is a low-viscosity liquid with a viscosity of approximately 5 to 50 cps. The uniformity of the mixture should be visually checked, and there should be no precipitation or phase separation. The finished peeling active ingredient mixture should be placed in a brown glass bottle or light-blocking plastic container, sealed, and stored under refrigerated conditions at 4°C to 10°C. Since it contains enzymes, it should be used for the production of the final product as soon as possible after preparation; however, as enzyme activity may decrease with long-term storage, it is recommended to use it within two weeks of the date of manufacture.

[0187] Stability tests are conducted on the mixture to monitor changes in the content of peeling active ingredients and enzyme activity. The stability test is performed under three temperature conditions: 4°C, 25°C, and 40°C. Samples are collected at weeks 0, 1, 2, and 4, and the content of AHA, BHA, and PHA is analyzed by HPLC, while enzyme activity is measured using an enzyme activity test kit. Stability is deemed to be ensured if, when stored at 4°C for 4 weeks, the content of each ingredient is maintained at 90% or more of the initial level and the enzyme activity is maintained at 80% or more.

[0188] The technical reasons, critical significance, and specific implementation methods of the above steps (c) and (c1) to (c6) are as follows.

[0189] Technical reasons for the moisturizing ingredient preparation step and critical significance of numerical ranges

[0190] (c1) Step: Formulation of hyaluronic acid by molecular weight

[0191] In this step, classifying hyaluronic acid into low, medium, and high molecular weights and combining them is a key strategy to achieve three-dimensional moisturizing effects on each layer of the skin. Hyaluronic acid is an excellent moisturizing ingredient capable of retaining up to 1,000 times its own weight in moisture, and its skin penetration depth and moisturizing mechanism differ depending on its molecular weight.

[0192] Low molecular weight hyaluronic acid with a molecular weight of less than 10 kDa can penetrate the stratum corneum to the deep epidermis and form water bonds at the dermal boundary to produce a moisturizing effect from within the skin. According to clinical studies, hydrangea extract increases the expression of hyaluronic acid synthases HAS-1, HAS-2, and HAS-3, and low molecular weight hyaluronic acid exhibits a synergistic effect with this endogenous hyaluronic acid synthesis to enhance skin hydration. However, at concentrations of less than 0.1% by weight, the concentration becomes diluted after penetration, failing to produce a significant moisturizing effect, and when exceeding 3% by weight, excessive osmotic pressure differences may cause skin irritation and reduce economic efficiency.

[0193] Medium molecular weight hyaluronic acid with a molecular weight of 10 kDa or more and 100 kDa or less is mainly distributed within the stratum corneum and increases the moisture content of the stratum corneum by retaining moisture in the intercellular spaces. This molecular weight range acts as a bridge connecting moisture between the skin surface and the deep layers, effectively reducing transepidermal water loss. Medium molecular weight hyaluronic acid plays an important role in filling the moisture gap between low and high molecular weight hyaluronic acid, and a concentration range of 0.1% to 3% by weight is a critical range that provides sufficient moisture retention capacity within the stratum corneum while maintaining the viscosity of the formulation appropriately.

[0194] High molecular weight hyaluronic acid with a molecular weight exceeding 100 kDa forms a protective film on the skin surface to physically block moisture evaporation and performs a barrier function to protect the skin from the external environment. Due to its high viscoelasticity, high molecular weight hyaluronic acid forms a film on the skin surface, which provides immediate hydration and improves the texture of the cosmetic product. Below 0.1 weight%, the film-forming effect is insufficient, and above 3 weight%, the viscosity of the formulation increases excessively, leading to reduced spreadability and stickiness.

[0195] By combining hyaluronic acid of three different molecular weights in amounts of 0.1 to 3 weight percent each, a three-dimensional moisturizing network is established across the entire layer from the skin surface to the dermal boundary. This provides significantly superior long-lasting moisturization compared to using hyaluronic acid of a single molecular weight and is the key mechanism behind the significant increase in skin hydration observed in clinical trials.

[0196] (c2) Step: Glycerin

[0197] Glycerin is a polyol compound with three hydroxyl groups that exhibits strong hygroscopic properties and is the most widely used moisturizer in the cosmetics field. The moisturizing mechanism of glycerin consists of two main parts: first, a hygroscopic action that absorbs moisture from the atmosphere and supplies it to the stratum corneum, and second, a moisture-binding action that binds moisture within the stratum corneum to inhibit evaporation.

[0198] The concentration range of 3% to 10% by weight is the critical range for achieving a balance between the moisturizing efficacy and the feel of glycerin. At a concentration below 3% by weight, the hygroscopic and water-binding effects are insufficient, resulting in short-lasting moisturization and limited synergistic effects with hyaluronic acid and other moisturizing ingredients. On the other hand, if it exceeds 10% by weight, excessive hygroscopic action may actually draw moisture from within the skin to the surface in low-humidity environments, potentially increasing transepidermal water loss. Additionally, a sticky sensation may occur, degrading the sensory quality of the cosmetic and potentially causing irritation in some sensitive skin types.

[0199] Glycerin also acts as a stabilizer for other moisturizing ingredients, promotes the hydration of hyaluronic acid, and increases the solubility of natural moisturizing factors. The range of 3 to 10 weight percent is a scientifically proven concentration range that optimizes these multifunctional roles while maintaining the overall balance of the formulation.

[0200] (c3) Step: Butylene Glycol

[0201] Butylene glycol is a diol compound with two hydroxyl groups on a four-carbon chain; it has a larger molecular weight and relatively higher hydrophobicity than glycerin. Due to these structural characteristics, butylene glycol provides a moisturizing effect while offering a lighter and fresher feel compared to glycerin.

[0202] The concentration range of 2% to 8% by weight is a setting intended to optimize the multifaceted functions of butylene glycol. First, as a moisturizing function, it increases the moisture content of the stratum corneum while providing a texture that is not sticky like glycerin. Below 2% by weight, the moisturizing effect is negligible, and above 8% by weight, greasiness may occur in some skin types.

[0203] Second, butylene glycol functions as a solvent and acts as a crosslinker between water-soluble and fat-soluble components. This improves the stability of the formulation and increases the solubility of the active ingredient. Third, butylene glycol acts as an adjuvant preservative to inhibit the growth of microorganisms. The range of 2 to 8 weight percent is a safe concentration that minimizes skin irritation while exhibiting these preservative effects.

[0204] In particular, when used in combination with peeling active ingredients such as AHA, BHA, and PHA, butylene glycol acts as a buffer that alleviates skin irritation caused by these ingredients while maintaining the exfoliating effect. This characteristic of butylene glycol contributes significantly to the realization of the low-irritation peeling effect of the present invention.

[0205] (c4) Step: Dipropylene glycol

[0206] Dipropylene glycol has a structure in which two propylene glycol units are bonded, and it has a higher molecular weight and hydrophobicity than butylene glycol. Due to these characteristics, dipropylene glycol is considered a moisturizer that provides the lightest feel.

[0207] The concentration range of 1% to 5% by weight is set considering the specialized functions of dipropylene glycol. Below 1% by weight, the moisturizing and solvent functions are insufficient, and above 5% by weight, it may cause dryness in some sensitive skin. Dipropylene glycol has relatively high volatility and provides a cooling sensation as it evaporates quickly after application to the skin; however, an excessive concentration poses a risk of evaporating moisture from the skin surface along with the evaporation during this process.

[0208] The primary role of dipropylene glycol is to improve the feel of the formulation. It optimizes the overall texture by adding lightness and freshness to the moisturizing effect provided by glycerin and butylene glycol. It also stabilizes the product's fragrance by increasing the solubility of fragrance ingredients and controlling their volatility. A range of 1 to 5 weight percent represents a balance point that exhibits these sensory improvement effects without negatively affecting the moisturizing efficacy.

[0209] By combining three polyol moisturizers—glycerin, butylene glycol, and dipropylene glycol—taking into account differences in molecular weight and hydrophobicity, the product simultaneously achieves maximum moisturizing efficacy and optimized user experience. This is a key strategy to enhance user compliance as a daily home care product.

[0210] (c5) Step: Natural moisturizing factors

[0211] Natural Moisturizing Factors (NMFs) are water-soluble low-molecular-weight substances present in the normal stratum corneum, primarily composed of amino acids, pyrrolidone carboxylic acid, lactates, urea, and minerals. As a key factor determining the moisture retention capacity of the stratum corneum, NMFs decrease in content when the skin is dry, leading to a decline in skin barrier function.

[0212] In this invention, sodium pyrrolidone carboxylate and five types of amino acids were selected as the main components of NMF. Sodium pyrrolidone carboxylate is the component with the highest content among NMFs and exhibits strong hygroscopic and moisturizing properties. Serine, glycine, and alanine are neutral amino acids that naturally exist in high concentrations in the stratum corneum, arginine is a basic amino acid that provides pH regulation and skin conditioning effects, and proline is a major constituent amino acid of collagen and is related to skin elasticity.

[0213] The purpose of setting each NMF component to 0.1% by weight to 1% by weight is to provide a replenishing effect while mimicking the skin's natural NMF composition. Below 0.1% by weight, the moisturizing effect is negligible and insufficient to replenish the skin's NMF depletion. If it exceeds 1% by weight, the following problems may occur for each component. Sodium pyrrolidone carboxylate may cause irritation due to excessive sodium ions, amino acids may act as a nutrient source for microorganisms and reduce the microbiological stability of the product, and some amino acids may cause a browning reaction and change the color of the product.

[0214] The purpose of combining six types of NMF ingredients is to comprehensively replicate the natural NMF composition of the skin's stratum corneum. Numerous studies have proven that complex ingredients offer superior moisturizing effects and are more effective in restoring skin barrier function than single ingredients. The increased expression of skin barrier factors, such as filaggrin and transglutaminase-1, reported in clinical papers, is expected to show synergy with this NMF supplementation.

[0215] (c6) Step: Mixing moisturizing ingredients

[0216] Mixing each of the above moisturizing ingredients at a temperature of 25°C to 35°C is a setting that simultaneously considers the stability of the ingredients and mixing efficiency. At temperatures below 25°C, the viscosity of glycerin and polyol components increases, making mixing difficult and hindering uniform dispersion. In particular, the hydration of high molecular weight hyaluronic acid may be incomplete, leading to the formation of lumps. At temperatures exceeding 35°C, the decomposition or denaturation of amino acids may begin, volatilization of some components may occur, and the risk of microbial growth increases.

[0217] A stirring speed of 200 rpm to 400 rpm is a range that provides sufficient mixing power while minimizing foam generation. Below 200 rpm, the dispersion of high molecular weight hyaluronic acid is incomplete and variations between components occur. If it exceeds 400 rpm, the molecular weight of hyaluronic acid may decrease due to excessive shear force, and a large amount of foam is generated due to air entrainment, requiring degassing treatment in subsequent processes.

[0218] A mixing time of 10 to 20 minutes is the time required for all ingredients to be homogeneously dispersed and for hyaluronic acid to be sufficiently hydrated. If the time is less than 10 minutes, mixing is incomplete, resulting in concentration variations within the formulation, and if it exceeds 20 minutes, the additional mixing effect is minimal while only the processing time increases.

[0219] Setting the total concentration of moisturizing ingredients to 6.9% by weight to 38% by weight is a critical range that considers the balance between the moisturizing efficacy of the cosmetic and the stability of the formulation. Below 6.9% by weight, the moisturizing effect is insufficient, making it difficult to achieve a clinically significant increase in skin hydration. If it exceeds 38% by weight, the viscosity of the formulation becomes excessively high, reducing spreadability, and precipitation or phase separation of some ingredients may occur, and stickiness becomes severe, significantly reducing the user experience.

[0220] The significant increase in skin hydration observed after 4 weeks of use in clinical trials is directly related to the scientific formulation of these moisturizing ingredients. Each ingredient acts independently yet exhibits mutually complementary synergy, delivering an all-encompassing moisturizing effect from the skin surface to the deep layers.

[0221] Specific implementation methods for each step

[0222] (c1) Specific implementation method of step

[0223] For low molecular weight hyaluronic acid, products with a molecular weight of less than 10 kDa are selected; generally, products with a molecular weight in the range of 1 kDa to 8 kDa are commercially available. Low molecular weight hyaluronic acid is supplied in powder or aqueous solution form; in the case of the powder form, it is first dissolved in purified water before use. Accurately weigh the low molecular weight hyaluronic acid powder and place it in a beaker, then add purified water equivalent to 5 to 10 times the target concentration. Stir the mixture using a magnetic bar at room temperature for 30 minutes to 1 hour to ensure complete dissolution.

[0224] After dissolution, dilute with purified water so that the final concentration is between 0.1% by weight and 3% by weight. For example, to prepare 100 g of a low molecular weight hyaluronic acid solution with a final concentration of 1% by weight, weigh 1 g of low molecular weight hyaluronic acid powder, add about 80 g of purified water to completely dissolve it, and then add more purified water to adjust the total weight to 100 g. If foam occurs during the dissolution process, remove it by letting it stand or centrifuging. A small amount of a chelating agent or antioxidant may be added as a stabilizer, but this is limited to 0.1% by weight or less of the total formulation.

[0225] Medium molecular weight hyaluronic acid is used with a molecular weight of 10 kDa or more and 100 kDa or less, and the preparation method is similar to that of low molecular weight. However, since medium molecular weight hyaluronic acid has a relatively high viscosity, the dissolution time is extended to 1 to 2 hours, and the stirring speed is slightly increased to 200 rpm to 300 rpm. Raising the dissolution temperature slightly to 30℃ to 40℃ can accelerate the dissolution speed, but excessive temperatures should be avoided.

[0226] High molecular weight hyaluronic acid is a product with a molecular weight exceeding 100 kDa, and generally, products in the range of 500 kDa to 2000 kDa are used. Due to its very high viscosity, high molecular weight hyaluronic acid requires the longest dissolution time. The high molecular weight hyaluronic acid powder should be slowly dispersed in purified water; however, instead of adding it all at once, it should be added in small increments while stirring. Strong stirring is required to prevent the powder from aggregating and forming gel clumps, and the stirring speed should be set to 300 rpm to 500 rpm. The dissolution time takes 2 to 4 hours, and it is recommended to let it stand overnight after dissolution to ensure complete hydration.

[0227] Once hyaluronic acid solutions of three different molecular weights are prepared, place them in individual containers, label them, and store them under refrigerated conditions at 4°C or below until use. To prevent microbial contamination, use sterile containers and tools, and a small amount of preservative may be added. Reconfirm the concentration of each solution immediately before use, and verify the concentration using a viscometer or spectrophotometer if necessary.

[0228] (c2) Specific implementation method of step

[0229] Glycerin is generally cosmetic-grade glycerin with a purity of 95% or higher. Glycerin is supplied as a highly viscous, colorless, transparent liquid at room temperature and can be used directly without separate pretreatment. To prepare a glycerin solution of 3% to 10% by weight, first determine the target concentration. For example, to prepare 100 g of a 5% by weight glycerin solution, accurately weigh 5 g of glycerin and place it in a beaker.

[0230] Slowly add about 90 g of purified water to glycerin while stirring. Glycerin has a high affinity for water and mixes easily, but sufficient stirring is required due to its high viscosity. Prepare a homogeneous solution by stirring with a magnetic stirrer at a speed of 100 rpm to 200 rpm for 10 to 20 minutes. Since the temperature may rise during stirring, take care to maintain a temperature of 25°C to 30°C.

[0231] Check the final weight of the glycerin solution, and if it falls short of the target weight, add purified water to adjust it to exactly 100 g. A small amount of a chelating agent or pH adjuster may be added as a stabilizer, provided that this is 0.1% by weight or less of the total weight. The prepared glycerin solution can be stored at room temperature in a sealed container, but it is preferable to keep it refrigerated to prevent microbial contamination.

[0232] As viscosity increases with higher glycerin concentration, when preparing a high-concentration solution close to 10% by weight, the stirring time can be extended to 20 to 30 minutes and the stirring speed increased to 200 rpm to 300 rpm. Since glycerin is highly hygroscopic, the work must be performed quickly and the container sealed to minimize the absorption of moisture from the atmosphere during the weighing and mixing process.

[0233] (c3) Specific implementation method of step

[0234] For the butylene glycol, cosmetic-grade 1,3-butylene glycol with a purity of 95% or higher is used. Butylene glycol is a colorless, transparent liquid with low viscosity at room temperature and is easier to handle than glycerin. A target concentration is set to prepare a butylene glycol solution of 2% to 8% by weight. For example, to prepare 100 g of a 5% by weight butylene glycol solution, 5 g of butylene glycol is weighed using a precision balance.

[0235] Since butylene glycol is volatile, the weighing process should be performed quickly to account for weight loss due to evaporation. Place the weighed butylene glycol in a beaker and add about 90 g of purified water. Butylene glycol has excellent miscibility with water and mixes without stirring, but to ensure uniformity, stir at a speed of 100 rpm to 200 rpm for 5 to 10 minutes.

[0236] The mixing temperature is maintained at room temperature between 25°C and 30°C, and excessive temperature increases are avoided as they promote the volatilization of butylene glycol. The final weight is checked and adjusted with purified water to exactly 100 g. Since butylene glycol also functions as a solvent, active ingredients such as water-soluble vitamins or plant extracts can be dissolved together at this stage if necessary.

[0237] Small amounts of pH adjusters or antioxidants may be added as stabilizers; however, since butylene glycol itself provides an auxiliary preservative effect, the use of separate preservatives should be minimized. The prepared butylene glycol solution should be stored in an airtight container at room temperature or in the refrigerator, and the container's airtightness should be checked to prevent volatilization during long-term storage.

[0238] (c4) Specific implementation method of step

[0239] Dipropylene glycol is used as a cosmetic-grade product with a purity of 95% or higher, and it is a transparent liquid with low viscosity at room temperature. Since dipropylene glycol is more volatile than butylene glycol, extra caution is required when handling it. Determine the target concentration to prepare a dipropylene glycol solution of 1% to 5% by weight. For example, to prepare 100 g of a 3% by weight dipropylene glycol solution, quickly weigh 3 g of dipropylene glycol.

[0240] To minimize volatilization during weighing, use a weighing container with a stopper, and mix with purified water immediately after weighing. First, place about 95 g of purified water into a beaker, and slowly add the weighed dipropylene glycol while stirring. Although dipropylene glycol has excellent miscibility with water, sufficient stirring is required because temporary layer separation may occur due to differences in specific gravity. Stir at a speed of 100 rpm to 200 rpm for 5 to 10 minutes to prepare a completely homogeneous solution.

[0241] The mixing temperature is maintained between 25°C and 30°C; temperature control is important because the mixing speed slows down at low temperatures and volatilization increases at high temperatures. The final weight is measured to check for losses due to volatilization, and any shortfall is supplemented with purified water to ensure the total weight reaches exactly 100 g. Since dipropylene glycol also has the function of increasing the solubility of fragrance components, the fragrance can be added and dissolved together at this stage if necessary.

[0242] Stabilizers are used minimally, and since dipropylene glycol itself is effective in inhibiting microbial growth, separate preservatives may not be necessary. The prepared dipropylene glycol solution is stored in a highly airtight container under refrigeration; to prevent evaporation, the container is filled to the brim and headspace is minimized.

[0243] (c5) Specific implementation method of step

[0244] The natural moisturizing factor ingredients are each prepared as separate solutions and then mixed. First, for sodium pyrrolidone carboxylate, a cosmetic-grade powder product with a purity of 95% or higher is used. To prepare a solution of 0.1% to 1% by weight of sodium pyrrolidone carboxylate, for example, to make 100 g of a 0.5% by weight solution, 0.5 g of sodium pyrrolidone carboxylate is accurately weighed.

[0245] Place a small amount of purified water, approximately 20 g, into a beaker and slowly add the weighed sodium pyrrolidone carboxylate while stirring. Stir using a magnetic stirrer at a speed of 100 to 200 rpm for 10 to 20 minutes until the powder is completely dissolved. Although sodium pyrrolidone carboxylate has excellent water solubility and dissolves easily even at room temperature, it is added slowly to prevent lump formation. After complete dissolution, add purified water to adjust the total weight to 100 g.

[0246] Each amino acid solution is prepared individually. Serine, glycine, alanine, arginine, and proline are all L-type amino acids with a purity of 98% or higher. Each amino acid is prepared at a concentration of 0.1% to 1% by weight; for example, when each amino acid is prepared at 0.5% by weight, 0.5 g of each is weighed.

[0247] Since serine has somewhat low solubility at room temperature, dissolution is promoted by first dispersing it in a small amount of purified water and then stirring while heating to 30°C to 40°C. Glycine dissolves easily at room temperature because it has high solubility at a neutral pH. Alanine also has excellent water solubility and can be dissolved by stirring at room temperature without additional heating. Arginine is a basic amino acid with very high solubility in water; since dissolution raises the pH, it can be neutralized with a small amount of acid if necessary. Proline dissolves sufficiently by stirring at room temperature due to its high solubility and excellent stability resulting from its structural characteristics.

[0248] Once each amino acid solution is prepared, five amino acid solutions and a sodium pyrrolidone carboxylate solution are mixed in a single container. When mixing, each solution is added in equal amounts or at the designed ratio, and the mixture is uniformly mixed by stirring at a speed of 100 to 200 rpm for 10 minutes. The pH of the mixed natural moisturizing factor solution is measured to ensure it is within the range of 5.0 to 7.0, and adjusted with a small amount of acid or base if necessary.

[0249] Since amino acids can serve as a nutrient source for microorganisms, a preservative must be added to the natural moisturizing factor solution. Preservatives such as phenoxyethanol and ethylhexylglycerin are added at a concentration of 0.5% to 1% by weight and mixed thoroughly. The prepared solution is placed in a sterile container and stored under refrigerated conditions at 4°C or below, and aseptic procedures are strictly observed to prevent microbial contamination.

[0250] (c6) Specific implementation method of step

[0251] All moisturizing ingredient solutions prepared in the above step are combined into a single mixing container. For the mixing container, a jacketed container with sufficient capacity and temperature control, or a beaker placed in a temperature-controlled water bath, is used. The temperature of the mixing container is pre-set and stabilized to between 25°C and 35°C. A temperature sensor is installed inside the container to monitor the temperature in real time.

[0252] First, purified water acting as a solvent is added to a mixing container. The total concentration of moisturizing ingredients in the entire formulation is calculated to be between 6.9% by weight and 38% by weight, and the amount of purified water required to satisfy this is determined. For example, when preparing 1000 g of the final formulation and setting the total concentration of moisturizing ingredients to 20% by weight, approximately 700 g of purified water is added first.

[0253] Start the stirrer and begin stirring at a speed of 200 to 400 rpm. Use propeller-type or anchor-type stirring blades, selecting the appropriate shape based on the size and viscosity of the container. During stirring, sequentially add each moisturizing ingredient solution. Generally, it is efficient to add the ingredients in order from lowest viscosity to highest viscosity.

[0254] First, add the dipropylene glycol solution and stir for 2 minutes. Next, add the butylene glycol solution and stir for 2 minutes. Then, add the glycerin solution and stir for 3 minutes. Since glycerin has high viscosity, ensure sufficient stirring time. Add the natural moisturizing factor solution and stir for 2 minutes.

[0255] The hyaluronic acid solution is added sequentially, taking into account viscosity and molecular weight. First, the low molecular weight hyaluronic acid solution is added and stirred for 3 minutes. The medium molecular weight hyaluronic acid solution is added and stirred for 3 minutes. Finally, the high molecular weight hyaluronic acid solution is added slowly while increasing the stirring speed to 300 rpm to 400 rpm. Since high molecular weight hyaluronic acid has very high viscosity, it is not added all at once but is added in small amounts, and sufficient stirring is performed after each addition to prevent lump formation.

[0256] After all ingredients have been added, check the temperature and verify that it is maintained within the range of 25°C to 35°C. Achieve complete homogenization by stirring for an additional 5 to 10 minutes while maintaining a stirring speed of 300 to 400 rpm. If foam occurs during stirring, reduce the stirring speed or remove it using a vacuum degassing device.

[0257] Once mixing is complete, take a small sample to measure its appearance, viscosity, and pH. The appearance should be a clear or translucent viscous liquid free of suspended particles or precipitates. Viscosity is measured using a Brookfield viscometer, with a range of 1,000 to 5,000 cps generally being appropriate. The pH should be targeted at a range of 5.0 to 7.0; if it falls outside this range, it should be adjusted with a small amount of acid or base.

[0258] Check whether the total concentration of moisturizing ingredients has reached the target range of 6.9% by weight to 38% by weight. Record the amount of each ingredient added, sum it up, and calculate the total; if necessary, verify the actual concentration using a refractometer or dry weight method. If the concentration is insufficient, add the corresponding ingredient; if it is excessive, dilute with purified water.

[0259] The final mixture should be placed in a sealed container and stored in a cool, dark place, and transferred to the subsequent formulation stage within 24 hours if possible. If long-term storage is required, it should be stored under refrigerated conditions at 4°C or below, with additional preservatives added to ensure microbial stability. Periodically check for phase separation or precipitation during storage, and re-stir before use to restore uniformity.

[0260] The moisturizing ingredient mixture prepared in this way serves as a key intermediate constituting the final cosmetic composition together with hydrangea extract, peeling active ingredients, and elasticity-enhancing ingredients, and is an essential component for realizing the low-irritation peeling and moisturizing elasticity-enhancing effects of the present invention.

[0261] The technical reasons, critical significance, and specific implementation methods of the above steps (d) and (d1) to (d5) are as follows.

[0262] Technical reasons for the preparation stage of elasticity-enhancing ingredients and critical significance of numerical ranges

[0263] (d1) Step: Technical Significance of Peptide Components

[0264] The six types of peptides selected in this step each have a unique mechanism of action for improving skin elasticity, and their combined use maximizes collagen synthesis through a synergistic effect. Setting the peptide concentration to 0.001% by weight to 1% by weight is a critical range to ensure both efficacy and safety simultaneously.

[0265] Palmitoyl pentapeptide-4 directly promotes the synthesis of collagen types I and III in fibroblasts and increases procollagen production by activating the TGF-β signaling pathway. According to clinical studies, COL1A1 mRNA and protein expression were significantly increased when used in combination with hydrangea extract. At concentrations below 0.001 wt%, stimulation of fibroblasts is insufficient, resulting in a negligible effect on collagen synthesis; when exceeding 1 wt%, there is a risk of cytotoxicity, reduced cost-effectiveness, and no additional increase in efficacy is observed.

[0266] Palmitoyl tripeptide-1 exhibits a dual action of promoting the synthesis of collagen and fibronectin and preventing the degradation of existing collagen by inhibiting the activity of Matrix Metalloproteinases (MMPs). This peptide is particularly effective in photoaged skin and contributes to increased dermal thickness and reduced wrinkle depth. Palmitoyl tetrapeptide-7 inhibits the production of inflammatory cytokines such as IL-6 and IL-8, thereby preventing collagen degradation caused by chronic inflammation and improving the microinflammatory state of the skin.

[0267] Acetyl hexapeptide-8 possesses a unique mechanism that regulates the release of neurotransmitters to alleviate excessive contraction of facial muscles and inhibit the formation of facial wrinkles. Copper tripeptide-1 binds to copper ions to promote fibroblast proliferation and collagen synthesis, thereby accelerating the wound healing process. Carnosine has antioxidant and anti-glycation effects and prevents stiffness caused by collagen glycation by inhibiting the formation of advanced glycation end products (AGEs).

[0268] Formulating these six types of peptides in a range of 0.001% to 1% by weight for each is done considering the minimum effective concentration and maximum safe concentration of each peptide. 0.001% by weight is the minimum concentration at which the peptide can reach target cells and initiate receptor binding and signal transduction, and 1% by weight is the maximum concentration at which safety as a cosmetic ingredient is ensured and the stability of the formulation is maintained. The optimal concentration within this range is selected by considering the molecular weight, solubility, and skin permeability of each peptide.

[0269] (d2) Step: Technical Significance of Adenosine

[0270] Adenosine is an ingredient recognized by the Ministry of Food and Drug Safety of the Republic of Korea as a functional ingredient for wrinkle improvement, and it has a dual mechanism of action that promotes collagen synthesis in dermal fibroblasts and inhibits the expression of MMP-1. A concentration range of 0.01% to 0.5% by weight is a range in which efficacy and safety as a cosmetic ingredient have been proven.

[0271] Adenosine increases intracellular cAMP levels through adenosine receptors, which promotes the transcription of genes related to collagen synthesis. Additionally, adenosine promotes the regeneration of dermal tissue by increasing the expression of fibroblast growth factor (FGF). According to clinical studies, crow's feet significantly improved when a 0.04% concentration of adenosine was used for 8 weeks.

[0272] At concentrations below 0.01 wt%, receptor activation is insufficient, resulting in no significant wrinkle improvement effect; if it exceeds 0.5 wt%, only the cost of raw materials increases without additional efficacy, and erythema or itching may occur in some sensitive skin. In particular, high concentrations of adenosine can reduce the stability of the formulation and cause precipitation or crystal formation.

[0273] Adenosine has a molecular weight of approximately 267 and is hydrophilic, so the selection of appropriate solvents and stabilizers is essential. Generally, purified water is used as a solvent, and pH adjusters and chelating agents are used as stabilizers to prevent the hydrolysis of adenosine. Adenosine is most stable in the pH range of 5.0 to 7.0, and its decomposition is accelerated under strongly acidic or strongly alkaline conditions.

[0274] (d3) Step: Technical Significance of Retinol Derivatives

[0275] Retinol and its derivatives are the active forms of vitamin A and exhibit multifaceted skin improvement effects, such as promoting collagen synthesis, cell proliferation, and normalizing keratinization. Five types of retinol derivatives were selected to achieve an optimal combination by considering differences in safety, irritancy, and the speed of efficacy onset.

[0276] Retinol, as the basic form of retinoids, exerts its effects by being converted to retinoic acid via retinalaldehyde in the skin. Retinoic acid binds to nuclear retinoid receptors (RAR and RXR) to directly promote the transcription of collagen synthesis genes and prevents collagen degradation by inhibiting the expression of MMP-1, MMP-3, and MMP-9. Additionally, retinoic acid regulates the proliferation and differentiation of epidermal cells, normalizing skin turnover and increasing skin thickness.

[0277] However, retinol and retinoic acid have the disadvantage of low stability against oxygen, light, and heat, as well as high skin irritation. To compensate for this, retinyl palmitate and retinyl acetate are used together. Retinyl palmitate is a form in which palmitic acid is esterified to retinol; it offers excellent stability and low irritation, and provides sustained effects as it is slowly converted to retinol by esterases in the skin. Retinyl acetate possesses similar characteristics but exhibits a faster conversion rate.

[0278] Retinaldehyde is a form closer to retinoic acid than retinol; since it becomes retinoic acid through only a single step of oxidation, it exhibits rapid onset of action while being less irritating than retinoic acid. Additionally, retinalaldehyde has antibacterial properties, making it useful for acne-prone skin. Although retinoic acid demonstrates the most potent efficacy, it is often classified as a pharmaceutical ingredient, so it is used in cosmetics only at very low concentrations.

[0279] Setting the concentration of each retinol derivative to 0.01 wt% to 1 wt% represents a balance between efficacy and safety. Below 0.01 wt%, the collagen synthesis-promoting effect is negligible, while exceeding 1 wt% increases the risk of retinoid dermatitis, such as erythema, peeling, dryness, and itching. In particular, it is common practice to limit retinoic acid to 0.1 wt% or less. When used in combination with hydrangea extract as presented in clinical studies, retinol derivatives showed a synergistic effect in increasing COL1A1 expression.

[0280] (d4) Step: Technical Significance of Plant Collagen Precursors

[0281] The five types of plant extracts selected as plant-based collagen precursors each contain unique bioactive components that support collagen synthesis, and their combined use promotes dermal regeneration through a multifaceted approach.

[0282] Centella asiatica extract contains triterpenoid saponins such as asiaticoside, madecassoside, asiatic acid, and madecassic acid, which activate TGF-β signaling to directly increase collagen synthesis in fibroblasts. In addition, Centella asiatica extract promotes wound healing, suppresses inflammation, and stimulates angiogenesis, thereby creating a regenerative environment for dermal tissue. Studies have reported that Centella asiatica extract increases the synthesis of procollagen type I by up to 30%.

[0283] Red ginseng extract contains ginsenosides as its main components; in particular, ginsenosides such as Rg1, Rb1, and Rg3 promote the proliferation of fibroblasts and collagen synthesis. Furthermore, red ginseng extract possesses powerful antioxidant effects, preventing collagen degradation caused by free radicals and strengthening the skin's immune function to protect collagen from external stimuli. Clinical studies have shown that red ginseng extract contributes to skin regeneration through the activation of the AP-1 pathway.

[0284] Green tea extract contains catechins, including EGCG (Epigallocatechin Gallate), which exhibit powerful antioxidant and MMP inhibitory effects. Green tea extract inhibits UV-induced collagenase expression, prevents collagen glycation, and promotes procollagen synthesis in fibroblasts. Additionally, green tea extract has anti-inflammatory effects and inhibits collagen degradation caused by chronic inflammation.

[0285] Aloe vera extract contains various components such as polysaccharides, glycoproteins, enzymes, and vitamins, and promotes wound healing and skin regeneration. The mannan polysaccharides in aloe vera activate fibroblast growth factor receptors to promote cell proliferation and collagen synthesis, and increase the skin's moisture retention capacity, thereby creating an environment favorable for collagen synthesis.

[0286] Licorice extract contains components such as glycyrrhizic acid, glabridin, and lycochalcone, and exhibits anti-inflammatory, antioxidant, and whitening effects. Licorice extract inhibits the production of inflammatory cytokines to prevent collagen degradation caused by inflammation, improves pigmentation by inhibiting tyrosinase activity, and prevents oxidative damage to collagen through its antioxidant effect.

[0287] The concentration of each plant extract is set to 0.1% by weight to 5% by weight, a range that takes into account the content of active ingredients and safety. Below 0.1% by weight, the concentration of physiologically active ingredients is insufficient, resulting in a negligible effect on collagen synthesis promotion; above 5% by weight, irritation or allergic reactions may occur in some sensitive skin, and the color or scent of the extract may negatively affect the sensory characteristics of the product. Additionally, high concentrations of plant extracts can reduce the stability of the formulation and increase the risk of microbial contamination.

[0288] (d5) Step: Critical Significance of the Elasticity-Enhancing Component Mixture

[0289] The total concentration of elasticity-enhancing ingredients is set to 0.566 wt% to 36.5 wt%, which is the range obtained by summing the minimum and maximum concentrations of each ingredient group. The lower limit of 0.566 wt% is the sum of 0.001% of 6 types of peptides, 0.01% of adenosine, 0.01% of 5 types of retinol derivatives, and 0.1% of 5 types of plant extracts, and represents the minimum concentration required to exhibit an elasticity-enhancing effect. Below this concentration, the effects of the individual ingredients fall below the threshold, so no significant collagen synthesis promotion or wrinkle improvement effect is observed.

[0290] The upper limit of 36.5 wt% is the sum of 6 types of peptides × 1%, adenosine 0.5%, 5 types of retinol derivatives × 1%, and 5 types of plant extracts × 5%, representing the maximum concentration at which safety and formulation stability are ensured. If this concentration is exceeded, precipitation or separation may occur due to interactions between ingredients, the risk of skin irritation increases due to excessive active ingredients, and the physical stability of the formulation is reduced due to insufficient proportions of solvents and stabilizers.

[0291] By adjusting the concentration of each ingredient within this range, customized formulations tailored to various skin types and age groups can be developed. For example, a concentration close to the lower limit can be selected for preventive use in younger age groups, while a concentration close to the upper limit can be chosen for intensive care in middle-aged and older adults. The wrinkle improvement and elasticity enhancement effects presented in clinical studies were achieved through a formulation optimized within this concentration range.

[0292] Specific implementation methods for each step

[0293] (d1) Specific implementation method of step

[0294] The preparation of peptide components begins with selecting appropriate solvents and stabilizers by considering the physicochemical properties of individual peptides. Since palmitoylpentapeptide-4 has a molecular weight of approximately 580 and possesses amphiphilic properties, it is dissolved in a mixed solvent of purified water and glycerin or butylene glycol. Generally, the solvent is prepared in a ratio of 70 wt% purified water, 25 wt% glycerin, and 5 wt% butylene glycol.

[0295] The peptide powder is accurately weighed using a precision balance and calculated to achieve a target concentration of 0.001% to 1% by weight. For example, when preparing 100g of the final mixture and setting the concentration of palmitoylpentapeptide-4 to 0.05% by weight, 50mg of peptide is weighed. The weighed peptide is first dispersed in a small amount of solvent, and then treated using an ultrasonic processor for 5 to 10 minutes to completely dissolve it. Care must be taken to prevent the temperature from rising excessively during ultrasonic treatment, and if necessary, it is cooled with ice water.

[0296] A stabilizer is added to the peptide solution. Citric acid or sodium citrate, which are pH adjusters, are used as stabilizers to adjust the pH to a range of 5.0 to 6.5, and 0.01% to 0.1% by weight of EDTA, which is a chelating agent, is added to prevent peptide degradation by metal ions. Additionally, 0.01% to 0.05% by weight of tocopherol or BHT, which are antioxidants, are added to prevent oxidation.

[0297] Palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, and acetyl hexapeptide-8 are prepared in the same manner, but the solvent composition is finely adjusted according to the solubility of each peptide. Since copper tripeptide-1 contains copper ions, it is prepared separately and stored separately so that it can be added at the end to avoid interaction with other metal ions or chelating agents. For copper tripeptide-1, purified water is used as the main solvent and the pH is adjusted to 6.0–7.0.

[0298] Carnosine is an amino acid derivative with excellent water solubility, so it is dissolved directly in purified water. Since carnosine is sensitive to oxidation, stability is ensured by replacing it with nitrogen gas or adding antioxidants. Each prepared peptide solution is filtered through a 0.22 µm membrane filter to remove microorganisms and fine particles, and then stored in a brown or light-shielding container at 4°C. It is preferable to use the peptide solution within 48 hours of preparation if possible, and for long-term storage, it should be frozen to prevent decomposition.

[0299] (d2) Specific implementation method of step

[0300] Adenosine is a white to off-white crystalline powder with a molecular weight of 267 and a melting point of 234 to 238°C. Since adenosine is slightly soluble in cold water and highly soluble in hot water, the temperature is controlled to increase dissolution efficiency. The adenosine powder is precisely weighed to achieve a target concentration of 0.01% to 0.5% by weight.

[0301] Heat purified water to 60°C to 80°C, and add weighed adenosine in small amounts while stirring with a magnetic stirrer. Set the stirring speed to 300 rpm to 500 rpm to form a vortex so that the powder is efficiently dispersed. Continue stirring for 30 minutes to 1 hour until the adenosine is completely dissolved, and maintain the heater to prevent the temperature from dropping.

[0302] Once the adenosine is completely dissolved, cool the solution to 40°C or below. Continue stirring during cooling to prevent recrystallization. Since adenosine is sensitive to pH, check the pH with a pH meter and adjust it to a range of 5.5 to 6.5 using a pH adjuster. If the pH is below 5.0, the N-glycosidic bonds of adenosine may be hydrolyzed, and if the pH exceeds 7.0, the oxidation reaction may be accelerated.

[0303] 0.05 wt% of EDTA-2Na, a chelating agent, is added as a stabilizer to prevent the decomposition of adenosine by trace amounts of metal ions. Additionally, 0.01 wt% to 0.05 wt% of sodium ascorbate or tocopherol, which are antioxidants, are added to prevent oxidation. If necessary, a preservative is added to ensure microbiological safety.

[0304] To enhance the stability of the adenosine solution, a small amount of water-soluble polymers such as sodium hyaluronate or carbomer may be added to increase viscosity and limit the mobility of adenosine. This helps prevent the precipitation of adenosine and maintain the uniformity of the formulation. The prepared adenosine solution is filtered through a 0.22 µm filter to remove microorganisms and insoluble particles, and then stored in a brown container under a light-shielded refrigerator. Since adenosine is sensitive to photodegradation, it must always be stored and handled under light-shielded conditions.

[0305] (d3) Specific implementation method of step

[0306] Retinol and its derivatives are extremely sensitive to oxygen, light, and heat, so special care is required during the preparation process. All operations should be performed in a glove box under a nitrogen or argon atmosphere whenever possible, or at least carried out rapidly under light-shielded conditions. All containers and equipment used must be pre-filled with nitrogen gas to remove oxygen.

[0307] Since retinol and retinol derivatives are fat-soluble, an appropriate oily solvent is selected. Generally, esters such as squalane, caprylic / capric triglycerides, and ethylhexyl palmitate are used as solvents. In the case of retinol, vitamin E (tocopherol) is added in an amount of 5% to 10% by weight as a co-solvent and stabilizer, particularly considering stability.

[0308] Weigh the retinol powder or retinol raw material using a precision balance, taking into account the purity of the retinol, and calculate the actual content so that it is a target concentration of 0.01% to 1% by weight. Since commercially available retinol raw materials have a purity of 95% to 99%, this is taken into account. The weighing process should be carried out as quickly as possible, and the time exposed to air should be minimized.

[0309] Weighed retinol is added to a pre-prepared oily solvent and completely dissolved by stirring with a magnetic stirrer at room temperature or a temperature of 30°C or lower. Excessive temperature should be avoided as it promotes isomerization or decomposition of retinol. A stirring time of 10 to 30 minutes is appropriate, and the stirring speed is set to 200 rpm to 400 rpm.

[0310] Retinyl palmitate and retinyl acetate are more stable than retinol, making them easier to handle. They are available in wax or oil form and are heated to 60°C to 70°C to increase fluidity, after which they are mixed with a solvent. Retinaldehydride is prepared in a manner similar to that of retinol, but since it is more sensitive to oxidation than retinol, it is handled under stricter light-shielding and nitrogen atmosphere conditions.

[0311] Since retinoic acid can be classified as a pharmaceutical ingredient, it is used in cosmetics only at very low concentrations. Because retinoic acid has acidic properties, care must be taken to control the pH, and the pH can be adjusted to a range of 4.5 to 5.5 by adding a small amount of neutralizing agent after dissolving it in a lipid-soluble solvent.

[0312] To each retinol derivative solution, 0.05% to 0.1% by weight of BHT or BHA is added as an antioxidant, and 0.01% by weight of EDTA fatty acid ester as a chelating agent is added to prevent metal catalyst oxidation. The prepared retinol derivative solution is immediately placed in a light-shielding, sealed container, the headspace is replaced with nitrogen gas, and the container is sealed. It is stored under refrigerated conditions at 4°C or below, and mixed into the final formulation as soon as possible after preparation. Since the activity of retinol derivatives decreases with long-term storage, it is preferable to use them within one month.

[0313] (d4) Specific implementation method of step

[0314] The five types of plant extracts used as plant-based collagen precursors are generally provided in the form of liquid extracts or powder extracts. The form and solid content of each extract are checked, and the amount to be used is determined by converting it to a target concentration of 0.1% to 5% by weight.

[0315] In the case of Centella asiatica extract, it is advisable to select a standardized product based on its asiaticoside content. Generally, products containing 40% or more asiaticoside or 70% or more total triterpenoids are used. If the extract is in powder form, it is first dissolved in a suitable solvent. Since Centella asiatica extract contains both water-soluble and fat-soluble components, a mixed solvent of purified water and propylene glycol or butylene glycol is used. Generally, a ratio of 50% by weight of purified water, 40% by weight of butylene glycol, and 10% by weight of ethanol is appropriate.

[0316] First, the weighed Centella asiatica extract powder is dispersed in a small amount of ethanol to wet it, then butylene glycol is added and stirred. Subsequently, purified water is slowly added while continuously stirring until completely dissolved. Stirring is performed at a speed of 500 to 800 rpm for 30 minutes to 1 hour. If the extract is in liquid form, the solid content is measured and calculated, then used directly or diluted with a solvent.

[0317] For red ginseng extract, select a standardized product based on ginsenoside content. Generally, use a product that specifies a total ginsenoside content of 10% or more, or the content of major ginsenosides (Rb1, Rg1, Rg3, etc.). Since red ginseng extract is water-soluble, purified water is used as the main solvent, but 20% to 30% by weight of glycerin or propylene glycol is added to increase solubility. Because red ginseng extract has a strong characteristic color and aroma, the concentration used is determined by considering the sensory characteristics of the final product.

[0318] For green tea extract, select a product standardized based on catechin content, particularly EGCG content. Generally, use a product containing at least 50% total catechins or at least 30% EGCG. Since green tea extract is water-soluble, dissolve it in purified water, but add an antioxidant to prevent the oxidation of catechins. Adjust the pH to a range of 4.5 to 5.5, as excessive alkaline conditions accelerate the oxidation of catechins, causing discoloration.

[0319] Select a standardized aloe vera extract product based on its polysaccharide content or aloveroside content. When using aloe vera gel directly, wash the leaves, separate only the gel portion, homogenize it, and filter it for use. When using commercially available extracts, dilute them with purified water before use as they are in the form of a concentrate or powder. Since aloe vera extract is susceptible to microbial contamination, add an appropriate amount of preservatives.

[0320] For licorice extract, select a product standardized based on the glycyrrhizic acid or glabridin content. Since glycyrrhizic acid is water-soluble and glabridin is fat-soluble, select an appropriate solvent depending on the type of extract. Standardized glycyrrhizic acid products are dissolved in purified water, while standardized glabridin products are dissolved in ethanol or propylene glycol. Since licorice extract also has a distinctive sweet taste and color, consider its impact on the final product.

[0321] Each prepared plant extract solution is filtered through a 0.45 µm or 0.22 µm filter to remove insoluble particles and microorganisms. The filtered extracts are placed in individual containers, labeled, and stored in a cool, dark place. Since there is a risk of microbial contamination and degradation of components, it is advisable to use the plant extracts within 2 weeks if possible.

[0322] (d5) Specific implementation method of step

[0323] The preparation of the elasticity-enhancing ingredient mixture is carried out sequentially, taking into account the compatibility and stability of each ingredient. First, the mixing container is prepared and its cleanliness is verified. The container must be made of stainless steel and washed with purified water and ethanol beforehand and dried. The mixing container must be equipped with a stirrer and capable of adjusting the stirring speed.

[0324] The mixing sequence begins with the water-soluble components. First, the basic base of the solvent and stabilizer is added to the mixing container. Generally, an aqueous base is prepared in the ratio of 40% to 60% by weight of purified water, 10% to 20% by weight of glycerin, 5% to 10% by weight of butylene glycol, and 3% to 7% by weight of dipropylene glycol. Each component is added while stirring at a speed of 200 rpm to 300 rpm by operating a stirrer.

[0325] Once the aqueous base is prepared, water-soluble elasticity-enhancing ingredients are added sequentially. First, the adenosine solution is added and stirred for 5 minutes to ensure thorough mixing. Subsequently, the water-soluble peptide solutions are added one by one, stirring for 5 minutes after each addition to ensure uniform dispersion. The order of peptide addition is Palmitoyl Pentapeptide-4, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Acetyl Hexapeptide-8, Carnosine, and Copper Tripeptide-1. Since Copper Tripeptide-1 contains metal ions, it is added last to minimize interaction with other ingredients.

[0326] Add plant extracts. Add Centella asiatica extract, red ginseng extract, green tea extract, aloe vera extract, and licorice extract sequentially, stirring for 5 minutes after each addition. Since plant extracts may have a dark color and high viscosity, add them in small amounts to prevent lump formation.

[0327] Once the mixing of the water-soluble components is complete, the fat-soluble components are added. Prepare a retinol derivative solution; since the retinol derivative is fat-soluble, it may be added together with an emulsifier or prepared as a separate oil phase for emulsification mixing in a subsequent step. To ensure the stability of the retinol derivative, maintain the mixing temperature at 40°C or lower and work under light-shielded conditions.

[0328] Retinol, retinyl palmitate, retinyl acetate, retinaldehydride, and retinoic acid solutions are added sequentially, and after each addition, they are stirred sufficiently to be uniformly dispersed. When mixing fat-soluble components, the stirring speed is increased to 300 rpm to 500 rpm, and a homomixer is used to process at a speed of 1000 rpm to 3000 rpm for 5 to 10 minutes to achieve fine and uniform dispersion.

[0329] Once all ingredients have been added, measure the pH of the mixture. Check the pH of the mixture using a pH meter and adjust it to a range of 5.0 to 6.5 using a pH adjuster. If the pH is low, neutralize it with triethanolamine or a sodium hydroxide solution; if the pH is high, acidify it with citric acid or lactic acid. After adjusting the pH, stir for an additional 10 minutes to ensure a uniform distribution of pH.

[0330] Finally, a stabilizer is added to the mixture. 0.05% to 0.1% by weight of EDTA-2Na, a chelating agent, is added to prevent the decomposition of components by metal ions, and 0.05% to 0.1% by weight of tocopherol or sodium ascorbate, antioxidants, is added to prevent oxidation. 0.5% to 1% by weight each of phenoxyethanol and 1,2-hexanediol are added as preservatives to ensure microbiological safety.

[0331] After adding the stabilizer, continue stirring for 30 minutes to ensure all ingredients are completely mixed and a uniform solution is formed. Visually inspect the appearance of the elasticity-enhancing ingredient mixture once mixing is complete to check for any precipitation, separation, or discoloration. The solution must be clear and uniform; if it is opaque or precipitation is observed, perform additional stirring or homomixer treatment.

[0332] The prepared elasticity-enhancing ingredient mixture is filled into a light-shielding, sealed container. The container is made of a brown or opaque material to prevent photodegradation and is sealed to minimize exposure to oxygen. A label indicating the manufacturing date, ingredient composition, concentration, batch number, etc., is attached to the container. It is stored under refrigerated conditions at 4°C or below, and direct sunlight is avoided. It is preferable to use the prepared mixture for the preparation of the final cosmetic composition within two weeks if possible, and its quality is verified before use through visual inspection, pH measurement, viscosity measurement, etc.

[0333] The technical reasons, critical significance, and specific implementation methods of the above steps (e) and (e1) to (e6) are as follows.

[0334] Technical reasons for the mixing stage and critical significance of the numerical range

[0335] (e) Setting the mixing ratio for the entire mixing stage

[0336] In this invention, the formulation ratio set to 5 to 30 parts by weight of hydrangea extract, 1 to 15 parts by weight of a peeling active ingredient, 10 to 40 parts by weight of a moisturizing ingredient, and 1 to 20 parts by weight of an elasticity-enhancing ingredient represents the optimal range resulting from a comprehensive consideration of clinical trial results and the concentrations at which each ingredient demonstrates efficacy. In the case of hydrangea extract, at a ratio of less than 5 parts by weight, the absolute amount of hydrangenol is insufficient, resulting in insufficient activation of the AP-1 pathway and the Akt / PI3K pathway, and a significant increase in the expression of hyaluronic acid synthase is not observed. Considering that a cream containing 0.5% hydrangea extract showed significant effects in clinical studies, at least 5 parts by weight is required to ensure a concentration of at least 0.5% in the final product.

[0337] On the other hand, if the amount of hydrangea extract exceeds 30 parts by weight, the additional increase in efficacy is minimal, while the cost of raw materials increases excessively, and the color of the formulation becomes excessively dark, which may reduce consumer preference. In addition, an excessive amount of hydrangea extract may affect the stability of the formulation and cause precipitation or separation. Therefore, the range of 5 to 30 parts by weight is a critical range that can simultaneously ensure efficacy, cost-effectiveness, and formulation stability.

[0338] In the case of peeling active ingredients, if the amount is less than 1 part by weight, the exfoliation effect is insufficient, making it impossible to achieve the low-irritation peeling function pursued by the present invention. Even if AHA, BHA, PHA, and enzyme peeling agents are combined, if the total amount is less than 1 part by weight, the softening and removal of dead skin cells on the skin surface do not occur effectively. On the other hand, if the amount exceeds 15 parts by weight, the core characteristic of the present invention, which is low irritation, is lost, and skin irritation increases, making it unsuitable as a daily home care product for daily use. As mentioned in clinical papers, in order to solve the problem that existing peeling products cause irritation and are difficult to use frequently due to strong chemical ingredients, it is essential to limit the total amount of peeling active ingredients to 1 to 15 parts by weight.

[0339] The moisturizing ingredient is set in the range of 10 to 40 parts by weight, which is the formulation ratio constituting the core of the skin moisturizing effect. If the moisturizing ingredient is less than 10 parts by weight, even if hyaluronic acid of various molecular weights, glycerin, butylene glycol, dipropylene glycol, and natural moisturizing factors are complexly blended, the absolute amount is insufficient to achieve a three-dimensional moisturizing effect from the surface layer to the deep layer of the skin. The significant increase in skin hydration after 4 weeks of use in clinical trials is due to the inclusion of a sufficient amount of moisturizing ingredient. If it exceeds 40 parts by weight, the formulation becomes excessively sticky and heavy, leading to reduced consumer satisfaction, and the relative proportion of other functional ingredients decreases, weakening the peeling and elasticity-enhancing effects.

[0340] The elasticity-enhancing ingredient was set to 1 to 20 parts by weight. At less than 1 part by weight, even if various peptides, adenosine, retinol derivatives, and plant collagen precursors are combined, the effect of promoting procollagen synthesis is not sufficiently observed. Just as hydrangea extract improved wrinkles by increasing the mRNA and protein expression of COL1A1 in clinical papers, at least 1 part by weight of the elasticity-enhancing ingredient is required to maximize these effects. If it exceeds 20 parts by weight, the risk of skin irritation due to the excessive use of certain retinol derivatives or peptides increases, the stability of the formulation decreases, and raw material costs increase excessively.

[0341] (e1) Step: Mixing vessel temperature conditions

[0342] Maintaining the temperature of the mixing container at 20°C to 30°C is a key condition for simultaneously ensuring the physicochemical stability of each component and mixing efficiency. If the temperature is below 20°C, the fluidity of some high-viscosity moisturizing components decreases, making uniform mixing difficult, and excessive shear force is required during stirring, leading to increased energy consumption. In particular, at low temperatures, the activity of emulsifiers decreases, and some components may precipitate. Furthermore, low temperature conditions reduce the solubility of hydrangenol and other polyphenol compounds in hydrangea extract, thereby hindering the uniformity of the mixture.

[0343] On the other hand, at temperatures exceeding 30°C, the decomposition of heat-sensitive components may begin. In particular, enzyme peeling agents may experience changes in activity or denaturation at temperatures above 30°C, and some peptide components may also undergo structural changes due to heat. Furthermore, retinol derivatives are highly sensitive to heat and light, and oxidation and isomerization are accelerated under conditions exceeding 30°C. Hydrangenol in hydrangea extract may also experience accelerated oxidation reactions at excessive temperatures, potentially leading to a decrease in efficacy. The range of 20°C to 30°C is the optimal temperature range for ensuring appropriate fluidity and miscibility while maintaining the stability of all components.

[0344] (e2) Step: Prioritize addition of moisturizing ingredients and primary stirring

[0345] Introducing moisturizing ingredients first is a strategic choice to form the basic matrix of the cosmetic formulation. As water-soluble ingredients, moisturizing ingredients have a high affinity for water, and hyaluronic acid, glycerin, butylene glycol, etc., of various molecular weights are mixed to form a basic base with appropriate viscosity and structure. Once this base is stabilized, subsequent ingredients such as hydrangea extract, peeling active ingredients, and elasticity-enhancing ingredients can be uniformly dispersed and stabilized.

[0346] A stirring speed of 100 rpm to 300 rpm is a range designed to achieve effective mixing of moisturizing ingredients while preventing excessive bubble generation. At speeds below 100 rpm, the mixing of viscous ingredients, such as high molecular weight hyaluronic acid, is incomplete, and localized concentration differences occur. At speeds exceeding 300 rpm, excessive shear force can cause the molecular chains of hyaluronic acid to break, and excessive air entrainment leads to the generation of large amounts of bubbles, which impairs the appearance and stability of the product.

[0347] A stirring time of 5 to 15 minutes is sufficient time for the moisturizing ingredients to be completely mixed and to form a uniform solution. Stirring for less than 5 minutes results in incomplete mixing of the ingredients, leaving localized concentration variations, while stirring for more than 15 minutes provides minimal additional mixing effects, increases the risk of air entrainment, and unnecessarily extends the process time.

[0348] (e3) Step: Add hydrangea extract dropwise and stir a second time

[0349] Adding hydrangea extract dropwise is an essential method considering the extract's high concentration characteristics and pigment components. Since hydrangea extract contains high concentrations of various polyphenol compounds, including hydranzenol, adding a large amount at once can lead to localized supersaturation, which may result in precipitation or aggregation. Additionally, due to the intense color of the extract, adding it all at once can cause color non-uniformity, which may lead to stains or color variations on the appearance of the final product.

[0350] Dropping over a period of 3 to 10 minutes allows the extract to gradually disperse into the existing moisturizing ingredient base, thereby achieving a uniform concentration distribution. Rapid addition in less than 3 minutes does not fully exhibit the benefits of dropping and results in localized concentration variations, while excessively slow addition exceeding 10 minutes reduces process efficiency and may cause quality variations due to the difference in processing time between the previously added and later added parts.

[0351] Increasing the stirring speed to 250 rpm to 400 rpm is necessary for the effective dispersion of the extract. Since hydrangea extract has a higher viscosity and may have a different density than moisturizing ingredients, stronger stirring force is required. Below 250 rpm, the extract may not be completely dispersed and may concentrate locally or settle. If it exceeds 400 rpm, the oxidation of polyphenol compounds is promoted and bubble generation increases due to excessive shear force.

[0352] A stirring time of 10 to 20 minutes is sufficient time for the hydrangea extract to be uniformly dispersed and stabilized throughout the moisturizing ingredient base. Clinical studies have reported that hydrangea extract increases the expression of hyaluronic acid synthase via the AP-1 pathway, and for consistent efficacy to be achieved when applied to the skin, this bioactive ingredient must be uniformly distributed within the formulation.

[0353] (e4) Step: Dropping of peeling active ingredient and tertiary stirring

[0354] Adding the peeling active ingredient after the hydrangea extract is a sequence designed to consider the interactions between ingredients and pH stability. As AHAs, BHAs, and PHAs are acidic substances, adding large quantities at once can cause a rapid change in the mixture's pH, potentially affecting the stability of other ingredients. Adding them dropwise allows for gradual pH changes, enabling a buffering effect and facilitating pH control in subsequent steps.

[0355] Dropping over a period of 3 to 10 minutes ensures uniform dispersion of the peeling active ingredient and a gradual change in pH. Since enzyme peeling agents exhibit optimal activity within a specific pH range, rapid changes in pH can lead to enzyme denaturation. Through dropping, the pH is gradually adjusted, allowing each ingredient to be mixed in a stable state.

[0356] Setting the stirring speed to 150 rpm to 300 rpm takes into account the characteristics of the peeling active ingredient. At this stage, since the hydrangea extract has already been mixed and the viscosity of the formulation has been formed to some extent, an excessively high stirring speed is not required. Below 150 rpm, the dispersion of the peeling active ingredient is incomplete, and above 300 rpm, low molecular weight organic acids such as AHA or BHA may volatilize or oxidize, and bubble generation increases.

[0357] A stirring time of 10 to 20 minutes is an appropriate time for the peeling active ingredient to be fully integrated into the existing mixture and stabilized. At this stage, a synergistic effect begins to form between the peeling active ingredient and the hydrangea extract, specifically the antioxidant effect of the hydrangea extract, which alleviates the irritation caused by the peeling ingredient.

[0358] (e5) Step: Dropping of elasticity-enhancing ingredients and 4th stirring

[0359] Adding elasticity-enhancing ingredients last is a strategy to protect the stability of peptides and retinol derivatives to the maximum extent. Peptides are sensitive to acidic conditions or excessive shear forces, which can lead to structural changes, while retinol derivatives are highly susceptible to oxidation. When elasticity-enhancing ingredients are added after moisturizing ingredients, hydrangea extract, and peeling active ingredients have already formed a stabilized matrix in the preceding steps, they mix in a protected environment, thereby improving stability.

[0360] Dropping over 3 to 10 minutes ensures that expensive peptides and retinol derivatives are uniformly dispersed throughout the formulation and prevents precipitation or crystallization caused by localized high concentrations. Plant collagen precursors such as Centella asiatica extract and red ginseng extract are also gradually fused with the existing mixture through dropping.

[0361] Increasing the stirring speed again to 250 rpm to 400 rpm is necessary for the effective dispersion of the elasticity-enhancing ingredients. Since the viscosity of the formulation reaches its peak at this stage, sufficient stirring force is required, and in particular, appropriate shear force is required to ensure uniform distribution of macromolecules such as peptides. Below 250 rpm, the elasticity-enhancing ingredients are not completely dispersed, and above 400 rpm, structural damage to the peptides and oxidation of retinol are promoted.

[0362] Setting the stirring time to 15 to 30 minutes, which is longer than other steps, is intended to provide sufficient time for the elasticity-enhancing ingredients to be fully incorporated into the final mixture and for the interactions between all ingredients to stabilize. Clinical studies have shown that when used with hydrangea extract, collagen synthesis was promoted and wrinkles were improved, which is due to the proper manifestation of the synergistic effect between the hydrangea extract and the elasticity-enhancing ingredients. Sufficient mixing time is essential to optimize this synergy at the formulation stage.

[0363] (e6) Step: Vacuum degassing

[0364] Vacuum degassing is an essential process for improving product appearance, stability, and usability by removing air introduced during the mixing process. Bubbles inevitably generated during mixing reduce product transparency, and oxygen-containing bubbles accelerate the decomposition of oxidation-sensitive ingredients such as hydrangenol and retinol derivatives. Furthermore, products containing a large amount of bubbles exhibit separation during pumping or application and make it difficult to provide a consistent volume.

[0365] A vacuum condition of 0.01 MPa to 0.05 MPa is the range required to maintain the structure of the formulation while achieving effective degassing. If the vacuum level is less than 0.01 MPa, some volatile components may be lost due to excessive vacuum, and the formulation may boil violently, leading to structural destruction or the splashing of components. If it exceeds 0.05 MPa, the vacuum level is insufficient, and the removal of microbubbles is not completely achieved.

[0366] A processing time of 5 to 15 minutes is the optimal range considering the volume and viscosity of the mixture. Processing for less than 5 minutes results in incomplete bubble removal, while processing for more than 15 minutes provides minimal additional degassing effect, whereas the risk of oxidation or denaturation of some components increases. After vacuum degassing, the mixture becomes a uniform, bubble-free state and is ready to proceed to the subsequent formulation step.

[0367] Specific implementation methods for each step

[0368] (e1) Specific implementation method of step

[0369] Jacketed stainless steel containers shall be used for mixing, and the capacity shall be selected within the range of 50 L to 500 L depending on the batch size. Before use, the interior of the container shall be washed with a cleaning agent, rinsed with purified water, and then disinfected with 70% ethanol to prevent microbial contamination. After disinfection, the container shall be dried with sterile air or air-dried.

[0370] To control the temperature, a constant temperature water bath is connected to the jacket or a cooling water circulation system is constructed. The constant temperature water bath is selected with specifications capable of precisely maintaining a temperature between 20°C and 30°C, and the temperature deviation is controlled to within ±1°C. Before starting the mixing operation, hot water is circulated through the jacket for at least 30 minutes to uniformly preheat the temperature of the container walls to the set temperature.

[0371] Temperature sensors are installed inside the container to monitor the actual temperature of the mixture in real time. These sensors are installed at the center of the container and near the walls to verify the uniformity of the temperature distribution. The stirrer is equipped with anchor-type, paddle-type, or turbine-type impellers, and the appropriate type is selected considering the viscosity and volume of the mixture. Mechanical seals or magnetic couplings are used to seal the stirring shaft to prevent contamination.

[0372] The work environment shall be a cleanroom or semi-cleanroom maintained at a temperature of 20°C to 25°C and a relative humidity of 40% to 60%. Workers shall wear sterile clothing, masks, and gloves, and disinfect their hands before commencing work. All tools and containers shall be sterilized or disinfected with alcohol.

[0373] (e2) Specific implementation method of step

[0374] Moisturizing ingredients are added in the form of a pre-prepared mixed solution. Low, medium, and high molecular weight hyaluronic acid are each dissolved separately in purified water and then mixed; in the case of high molecular weight hyaluronic acid, it is dissolved while stirring slowly until it is completely hydrated and forms a viscous solution. Rapid stirring should be avoided as it can cause molecular chain cleavage of the hyaluronic acid.

[0375] Glycerin, butylene glycol, and dipropylene glycol are each weighed and mixed in separate containers. Natural moisturizing factors, such as sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline, are prepared by dissolving them in a small amount of purified water. All of these ingredients are mixed to prepare a moisturizing ingredient mixture, but the mixing order is performed from the ingredient with the lowest viscosity to the ingredient with the highest viscosity to increase mixing efficiency.

[0376] 10 to 40 parts by weight of the prepared moisturizing ingredient mixture are added to a mixing container all at once. When adding, allow it to flow slowly along the inner wall of the container to minimize droplet generation. Immediately after adding, operate the stirrer, starting at a low speed of 50 to 100 rpm initially to ensure the ingredients are thoroughly mixed. After 1 to 2 minutes, gradually increase the stirring speed to reach a set speed of 100 to 300 rpm.

[0377] During stirring, check whether ingredients are adhering to the inner walls of the container, and if necessary, scrape them off with a rubber spatula or scraper to ensure uniform mixing. After 5 minutes of stirring, visually inspect the appearance, viscosity, and color of the mixture to evaluate the mixing status. Terminate the first stirring step when the hyaluronic acid is completely hydrated and all ingredients are uniformly mixed to form a transparent, viscous solution. Adjust the stirring time within the range of 5 to 15 minutes while monitoring the mixing status.

[0378] (e3) Specific implementation method of step

[0379] If the hydrangea extract is in powder form, it is prepared as a concentrated solution by pre-dissolving it in a small amount of purified water or glycerin. When dissolving, it is added slowly while stirring to prevent lump formation. Allow sufficient time for complete dissolution, which generally takes 30 minutes to 1 hour. After dissolution, fine insoluble particles can be removed by filtering through a 0.45㎛ or 0.22㎛ filter.

[0380] After the first stirring is completed, the stirring speed of the mixing container is increased to 250 rpm to 400 rpm. The speed increase is carried out in stages to prevent the formation of bubbles caused by sudden changes in shear force. Once the stirring speed is stabilized, the prepared hydrangea extract solution is added dropwise using a dropping funnel or a peristaltic pump.

[0381] Dropping is performed at the center of the mixing container or at the point where a stirring vortex is formed. The dropping speed is adjusted to 0.5 to 3 parts by weight per minute, and a total of 5 to 30 parts by weight are added over 3 to 10 minutes. During dropping, changes in color and viscosity of the mixture are observed. It is checked whether the brown color of the hydrangea extract spreads uniformly throughout, and attention is paid to whether there are any locally dark areas.

[0382] Continue stirring even after the addition is complete to ensure that the hydrangea extract is completely dispersed. The stirring time should be set to 10 to 20 minutes, and should continue until the color of the mixture becomes completely uniform and no precipitation or separation is observed. During stirring, periodically take a small sample, spread it on a slide glass, and observe it under a microscope to check for the presence of particles or aggregates.

[0383] The temperature is continuously monitored and maintained within the range of 20°C to 30°C. If the temperature rises due to frictional heat generated by stirring, the temperature of the jacket cooling water is lowered to regulate it. Once secondary stirring is completed, the pH of the mixture is measured and recorded, and the color, viscosity, and appearance are evaluated to verify compliance with quality standards.

[0384] (e4) Specific implementation method of step

[0385] The peeling active ingredients are prepared by separately preparing AHA, BHA, PHA, and an enzyme peeling agent, and then mixing them. The AHA components—glycolic acid, lactic acid, mandelic acid, and citric acid—are prepared in aqueous solutions, and their respective concentrations and pH are checked. Salicylic acid, a BHA, is dissolved in an alcohol or glycol solvent, taking into account its solubility. Gluconolactone or lactobionic acid, PHAs, are dissolved in water.

[0386] Enzyme peeling agents such as papain, bromelain, pumpkin enzyme, and pineapple enzyme are prepared together with a stabilizer, and are taken out immediately before use from refrigerated storage to maintain enzyme activity. All of these are mixed to prepare a peeling active ingredient mixture, but a buffer solution is added as necessary to adjust the pH so that it does not become excessively low. The pH of the final mixture should be in the range of 3.0 to 4.0.

[0387] After the second stirring is completed, the stirring speed of the mixing vessel is adjusted to 150 rpm to 300 rpm. Lowering the speed compared to the previous step is intended to mitigate reactions sensitive to pH changes and prevent enzyme denaturation. 1 to 15 parts by weight of the prepared peeling active ingredient mixture are added dropwise over 3 to 10 minutes using a dropping funnel or peristaltic pump.

[0388] During the dropwise addition, a pH electrode is inserted into the mixture to monitor changes in pH in real time. As the pH of the mixture gradually decreases with the addition of the peeling active ingredient, the rate of dropwise addition is controlled so that this change proceeds gradually rather than abruptly. If the pH deviates significantly from the target range of 5.0 to 6.5, the dropwise addition can be temporarily stopped and adjusted by adding a small amount of pH adjuster.

[0389] After the dropwise addition is complete, continue stirring for 10 to 20 minutes to ensure that the peeling active ingredient is completely dispersed and the pH is stabilized. During stirring, observe changes in the appearance of the mixture and check for any increase in turbidity or precipitation. Since the enzyme peeling agent is a protein component, it may denature and increase in turbidity if pH or temperature conditions are inappropriate. Terminate the third stirring step when the mixture remains clear or maintains slight turbidity without precipitation.

[0390] (e5) Specific implementation method of step

[0391] For the elasticity-enhancing ingredients, peptides, adenosine, retinol derivatives, and plant-based collagen precursors are prepared separately. Peptides such as palmitoyl pentapeptide-4 and palmitoyl tripeptide-1 are dissolved in a small amount of purified water or glycerin if they are in powder form, and used as is if supplied in solution form. When dissolving peptides, avoid excessive stirring and mix gently.

[0392] Since adenosine has limited solubility in water, it is dissolved at a slightly higher temperature of 40°C to 50°C and then cooled to room temperature for use. Retinol derivatives are highly sensitive to light and oxygen, so they should be stored in brown bottles and prepared under a state filled with an inert gas. Retinol, retinyl palmitate, etc., are generally found in a form dissolved in an oil solvent.

[0393] For plant-based collagen precursors such as Centella asiatica extract, Korean red ginseng extract, green tea extract, aloe vera extract, and licorice extract, prepare individual extracts or use a mixed extract. Mix all of these to prepare a mixture of elasticity-enhancing ingredients, but add the retinol derivative immediately before mixing to prevent oxidation.

[0394] After the third stirring is completed, the stirring speed of the mixing container is increased again to 250 rpm to 400 rpm. This is to effectively disperse the elasticity-enhancing ingredients while the viscosity of the formulation has increased. 1 to 20 parts by weight of the prepared elasticity-enhancing ingredient mixture are added dropwise through a dropping funnel over a period of 3 to 10 minutes.

[0395] During the dropping process, the mixing container is shielded from light or lighting is minimized to prevent photodegradation of the retinol derivative. The dropping point is positioned at the center of the stirring vortex so that the elasticity-enhancing component is immediately dispersed into the mixture. The dropping rate is maintained constant to prevent localized aggregation of polymeric components such as peptides.

[0396] After the addition is complete, stir thoroughly for 15 to 30 minutes. Since this step is a critical process for the final integration of all functional ingredients, allocate sufficient time. During stirring, periodically check the uniformity, color, scent, and viscosity of the mixture. In particular, ensure that the retinol derivative containing oil components is completely emulsified with the aqueous component and does not separate.

[0397] At the end of stirring, a small sample is taken, spread onto a slide, and observed under a microscope to evaluate the dispersion and emulsification states of the particles. When the particles are uniformly dispersed and the size of the emulsion droplets is constant, the fourth stirring is terminated. The final pH, viscosity, and specific gravity of the mixture are measured, recorded, and compared with quality standards.

[0398] (e6) Specific implementation method of step

[0399] A vacuum degassing machine uses equipment consisting of a vacuum chamber and a vacuum pump. The size of the chamber should be selected considering the volume of the mixture, but extra space should be ensured so that the mixture occupies no more than 50% of the chamber volume. This is because the mixture may expand or bubble and overflow during vacuum processing.

[0400] Transfer the mixture, after the fourth stirring is completed, to the vacuum chamber. During transfer, to minimize air entrainment, let it flow slowly through the outlet at the bottom of the mixing container. Place the container holding the mixture inside the chamber and seal the chamber door. After confirming the seal, start the vacuum pump.

[0401] The vacuum level is lowered in stages. It is started with a weak vacuum of 0.08 MPa to 0.1 MPa, and the reaction of the mixture is observed. When bubbles are observed slowly rising and bursting on the surface of the mixture, normal degassing is proceeding. After 2 to 3 minutes, the vacuum level is gradually increased to finally reach 0.01 MPa to 0.05 MPa.

[0402] After reaching the set vacuum level, maintain it for 5 to 15 minutes. The processing time is adjusted according to the viscosity and bubble content of the mixture. If the viscosity is high, a longer time may be required as the rate of bubble rise is slow. During vacuum processing, monitor the condition of the mixture through the observation window of the chamber. Initially, a large number of bubbles burst on the surface, but bubble generation decreases over time.

[0403] Degassing is considered complete when almost no bubbles are observed and the surface of the mixture becomes flat and uniform. When releasing the vacuum, air is introduced slowly to avoid sudden pressure changes. The vacuum valve is opened gradually to return to atmospheric pressure over 1 to 2 minutes. Sudden pressure changes can form new bubbles within the mixture or destroy the formulation structure.

[0404] Open the chamber and remove the mixture. The degassed mixture exhibits a clear, uniform appearance free of bubbles, allowing for smooth pumping or application during use. Transfer the mixture to a sealed container, label it, and transfer it to the subsequent formulation stage. Record the temperature, vacuum level, and processing time at the completion of degassing, and take a small sample to keep as a quality inspection sample. After degassing, proceed with the mixture to the next process as quickly as possible to prevent re-contamination or degradation of ingredients.

[0405] The technical reasons, critical significance, and specific implementation methods of the above steps (f) and (f1) to (f9) are as follows.

[0406] Technical reasons for the formulation stage and critical significance of numerical ranges

[0407] (f1) Step: Prepare emulsifier

[0408] The emulsifier used in this step is a key ingredient that stably mixes the aqueous and oil phases to form a uniform emulsion and determines the product's texture and feel on the skin. The range of 0.3 to 3 parts by weight of cetearyl alcohol is the critical range for ensuring the viscosity and stability of the formulation. Below 0.3 parts by weight, emulsion stability is insufficient, leading to separation of the aqueous and oil phases and making it difficult to maintain quality throughout the product's shelf life. If it exceeds 3 parts by weight, the formulation becomes excessively heavy and sticky, and upon application to the skin, it may cause a white cast and clog pores, potentially leading to skin irritation. As an aliphatic alcohol, cetearyl alcohol functions as an emulsification aid and viscosity modifier, and also contributes to strengthening the skin barrier.

[0409] 0.2 to 2 parts by weight of glyceryl stearate acts as a nonionic emulsifier and serves as the main emulsifier for the O / W (oil-in-water) emulsion. Less than 0.2 parts by weight results in insufficient emulsifying power, making it difficult to form a stable emulsion; if it exceeds 2 parts by weight, excessive emulsification causes the formulation to become too watery or the emulsion particles to become excessively fine, leading to excessively rapid skin absorption and reduced surface moisturizing effect.

[0410] 0.2 to 2 parts by weight of PEG-100 stearate is a highly hydrophilic nonionic emulsifier that exhibits a synergistic effect with glyceryl stearate. Less than 0.2 parts by weight results in reduced stability of the emulsion system, while more than 2 parts by weight results in increased stickiness upon skin application and difficulty in removal during cleansing. PEG-100 stearate has excellent skin affinity, enabling effective emulsification while minimizing irritation.

[0411] 0.1 to 1.5 parts by weight of sorbitan oleate acts as a lipophilic emulsifier to assist in the formation of a W / O emulsion and appropriately adjusts the Hydrophile-Lipophile Balance (HLB) of the emulsion system. Less than 0.1 parts by weight results in incomplete emulsification of the oil phase components, while more than 1.5 parts by weight results in the formulation becoming excessively oily and losing its fresh feel. Sorbitan oleate also has a skin softening effect, contributing to the improvement of the product's texture.

[0412] 0.2 to 1.5 parts by weight of caprylyl / caprylglucoside acts as a nonionic surfactant, providing mild emulsifying action, and as a naturally derived ingredient, minimizes skin irritation. Less than 0.2 parts by weight results in a negligible emulsifying aid, while exceeding 1.5 parts by weight may weaken the skin barrier due to excessive surfactant activity. This ingredient plays a crucial role in helping to disperse hydrangea extract and peeling active ingredients, and in maintaining a low-irritation peeling effect.

[0413] (f2) Step: Prepare thickener

[0414] 0.05 to 1.5 parts by weight of carbomer, as a water-soluble polymer, increases the viscosity of the formulation and forms a gel structure, thereby improving the product's stability and usability. Below 0.05 parts by weight, the thickening effect is insufficient, resulting in a formulation that is excessively thin, causing it to run off upon skin application; consequently, the reduced skin contact time of the active ingredient leads to decreased efficacy. Above 1.5 parts by weight, the formulation becomes excessively hard, making skin application difficult, and excessive viscosity hinders the penetration of the active ingredient into the skin. Since carbomer exhibits a characteristic where viscosity increases rapidly upon neutralization by triethanolamine, a pH adjuster, the appropriate mixing ratio is critical.

[0415] 0.03 to 1 weight part of sodium acrylate / sodium acryloyl dimethyl taurate copolymer acts as a synthetic polymer thickener and exhibits a synergistic effect with carbomer. Below 0.03 weight parts, the thickening aid effect is negligible, and above 1 weight part, the texture of the formulation feels artificial, and a stuffy sensation may occur due to film formation upon skin application. This ingredient exhibits excellent stability against electrolyte and pH changes, making it suitable for the cosmetic composition of the present invention containing various active ingredients.

[0416] 0.02 to 0.5 parts by weight of polyisobutene acts as an oil phase thickener to strengthen the structure of the formulation and provide a non-sticky feel. Less than 0.02 parts by weight results in insufficient viscosity control of the oil phase, while more than 0.5 parts by weight results in the formulation becoming excessively heavy and slowing down skin absorption. Polyisobutene has low volatility and also has the effect of preventing transepidermal water loss by forming a protective barrier on the skin.

[0417] (f3) Step: Preservative preparation

[0418] 0.3 to 2 parts by weight of 1,2-hexanediol, as a polyhydric alcohol, exhibits both preservative and moisturizing effects. Less than 0.3 parts by weight results in insufficient inhibitory effect against microorganisms, failing to ensure the microbiological safety of the product, while exceeding 2 parts by weight may cause irritation in some sensitive skin. 1,2-hexanediol exhibits broad-spectrum antimicrobial activity against Gram-positive and Gram-negative bacteria and shows a synergistic effect, particularly when used with hydrangea extract and peeling active ingredients.

[0419] 0.2 to 1 part by weight of phenoxyethanol acts synergistically with 1,2-hexanediol as a preservative with a broad antimicrobial spectrum. Less than 0.2 parts by weight results in insufficient inhibitory effects against yeast and mold, while more than 1 part by weight results in a strong chemical odor and increased potential for skin irritation. Since phenoxyethanol is stable and effective over a wide pH range, it is suitable for the weakly acidic formulation of the present invention. The combined use of the two preservatives achieves an effective preservative effect while reducing the individual amounts used, thereby realizing a low-irritation formulation.

[0420] (f4) Step: Prepare pH adjuster

[0421] 0.01 to 1 part by weight of triethanolamine is used as a basic pH adjuster to neutralize carbomer and adjust the pH of the final product. Less than 0.01 parts by weight results in incomplete neutralization of carbomer, making it impossible to obtain a sufficient thickening effect, and the final pH does not reach the target range. If more than 1 part by weight is used, excessive neutralization causes the viscosity of the formulation to become excessively high, and residual triethanolamine may cause skin irritation.

[0422] The pH of the final product is set within the range of 5.0 to 6.5 to protect the skin barrier and minimize irritation by maintaining a pH similar to the skin's natural pH. Below pH 5.0, the keratolytic effect of peeling active ingredients AHA and BHA becomes excessively strong, leading to increased skin irritation and reduced stability of some protein-based peptide components. Above pH 6.5, the skin's natural slightly acidic environment becomes alkaline, weakening skin barrier function, reducing peeling effectiveness, and increasing the risk of microbial proliferation. As reported in clinical studies, a slightly acidic environment is optimal for promoting the activity of hyaluronic acid synthase and maximizing skin moisturizing effects.

[0423] (f5) Step: Add emulsifier and stir

[0424] The temperature range of 30°C to 50°C is the optimal temperature for the emulsifier to completely dissolve and form an effective emulsion structure. Below 30°C, solid emulsifiers such as cetearyl alcohol do not completely dissolve, resulting in the formation of a non-uniform emulsion; above 50°C, the hydrangenol and peptide components of the hydrangea extract blended in the previous step may be denatured by heat. A stirring speed of 300 rpm to 500 rpm provides appropriate shear force to uniformly disperse the emulsifier and form emulsion particles. Below 300 rpm, mixing is insufficient, and above 500 rpm, excessive air incorporation causes bubbles to form, degrading the appearance and stability of the product. A stirring time of 10 to 20 minutes is the essential time required for the emulsifier to completely disperse and for a stable emulsion structure to be formed.

[0425] (f6) Step: Add thickener and stir

[0426] Lowering the stirring speed to 200 rpm to 400 rpm when adding the thickener is intended to ensure swelling and uniform dispersion of the thickener. Below 200 rpm, the thickener aggregates locally to form gel clumps, and above 400 rpm, the polymer chains of the thickener are cut due to mechanical shearing, reducing the thickening effect. A stirring time of 15 to 30 minutes is essential for the thickener to be sufficiently hydrated and swollen to be uniformly dispersed throughout the formulation. In the case of carbomer, hydration requires a significant amount of time; if this time is insufficient, gel particles are observed in the final product and the texture becomes rough.

[0427] (f7) Step: Add preservative and stir

[0428] Lowering the stirring speed to between 150 rpm and 300 rpm when adding preservatives is intended to uniformly disperse the preservatives while maintaining the already formed formulation structure. Below 150 rpm, the dispersion of the preservatives is uneven, which may result in areas where the preservative effect is partially insufficient; above 300 rpm, the gel structure formed by the thickener is destroyed, causing a decrease in viscosity. A stirring time of 5 to 15 minutes is the optimal time to sufficiently disperse the preservatives without excessively disturbing the formulation structure.

[0429] (f8) Step: pH measurement and adjustment

[0430] pH measurement is performed using a calibrated pH meter, and pH uniformity is verified by taking samples from various parts of the formulation. If the measured pH is below 5.0, triethanolamine is added in small amounts to raise the pH; while a value exceeding 6.5 generally does not occur, it can be adjusted using a weak acid such as citric acid if necessary. Triethanolamine is added in small, divided doses; after each addition, the mixture is thoroughly mixed, and the pH is re-measured to ensure it reaches the target range. Excessive, all-in-one addition can lead to localized over-neutralization and cause rapid changes in the viscosity of the formulation.

[0431] (f9) Step: Cooling and final stirring

[0432] Cooling to 20°C to 30°C is intended to stabilize the formulation and determine the final viscosity. Cooling below 20°C may cause some components to crystallize or precipitate, while temperatures exceeding 30°C may result in an unstable formulation and significant quality changes due to temperature fluctuations after filling. A low stirring speed of 100 rpm to 200 rpm is used to ensure uniform cooling while mixing gently. Final stirring for 10 to 20 minutes is a finishing process to equalize the temperature of the formulation and ensure stable dispersion of all components. After undergoing this step, the cosmetic composition is ready to be transferred to the filling process as a uniform and stable cream or lotion formulation.

[0433] Specific implementation methods for each step

[0434] (f1) Specific implementation method of step

[0435] The preparation of the emulsifier begins with accurately weighing each component. Since cetearyl alcohol is in a solid or paste state, it is stored at room temperature before weighing to maintain appropriate hardness. The exact amount is determined within the range of 0.3 to 3 parts by weight, taking into account the viscosity and texture of the target formulation. Generally, 1.5 to 2.5 parts by weight is suitable for cream-type formulations, and 0.5 to 1.5 parts by weight is suitable for lotion-type formulations.

[0436] Glyceryl stearate is a white to off-white waxy solid and is weighed in the range of 0.2 to 2 parts by weight. Since this component forms the basic framework of the emulsion system together with cetearyl alcohol, accurate weighing is important. PEG-100 stearate is a cream-colored solid or paste and is weighed in the range of 0.2 to 2 parts by weight. Since this component is hygroscopic, it should be stored in a sealed container and weighed quickly.

[0437] Sorbitan oleate is an amber-colored viscous liquid, and 0.1 to 1.5 parts by weight are accurately weighed. Due to its high viscosity, the container should be gently warmed or a pipette used to measure the exact amount during weighing. Caprylyl / Capryl Glucoside is a colorless to pale yellow viscous liquid, and 0.2 to 1.5 parts by weight are weighed. Since this component mixes well with water, it can be prepared by mixing it with a small amount of purified water after weighing.

[0438] All weighed emulsifiers are placed together in a clean stainless steel container. The solid and liquid emulsifiers are mixed first, and if necessary, heated to 50°C to 60°C to completely melt the solid components. During this process, the mixture is stirred at a low speed to ensure that the components are uniformly mixed. The preparation is complete when the emulsifier mixture becomes a transparent or translucent, uniform liquid. The prepared emulsifier is maintained at 50°C or below and kept warm until it is fed into the subsequent process.

[0439] (f2) Specific implementation method of step

[0440] Carbomer is a white, fine powder, and 0.05 to 1.5 parts by weight are accurately weighed. Since carbomer is a very light powder, work should be done in an environment with appropriate humidity to minimize static electricity generation during weighing, and if possible, an antistatic weighing container should be used. Generally, 0.5 to 1.0 parts by weight is suitable for cream formulations, and 0.3 to 0.7 parts by weight is suitable for light gel formulations.

[0441] Sodium acrylate / sodium acryloyl dimethyl taurate copolymer is weighed in an amount of 0.03 to 1 part by weight as a white powder. This thickener has larger particles and better flowability than carbomer, making it easy to weigh. The mixing ratio with carbomer is generally appropriate to be about 2:1 to 3:1 for carbomer to this thickener.

[0442] Polyisobutene is a colorless, transparent, viscous liquid, and 0.02 to 0.5 parts by weight are weighed. Since the viscosity is very high, allow sufficient time during weighing to ensure it flows completely out of the container. If necessary, the fluidity can be increased by heating to 40°C to 50°C.

[0443] The thickener is prepared by separating the powder and liquid components. Carbomer and sodium acrylate / sodium acryloyldimethyltaurate copolymer are mixed together to create a homogeneous powder mixture. To do this, place the two powders in a clean plastic bag or airtight container and shake gently to mix. Exercise caution, as excessive stirring can generate dust. Polyisobutene is prepared separately and mixed into the oil phase when added. The prepared thickener is stored in a sealed container to prevent moisture absorption.

[0444] (f3) Specific implementation method of step

[0445] 1,2-hexanediol is a colorless, transparent, viscous liquid, and 0.3 to 2 parts by weight should be accurately weighed. Although this ingredient is liquid at room temperature, crystals may precipitate at low temperatures; therefore, check the container before use, and if crystals are present, gently heat it to completely melt them before use. Generally, 1 to 1.5 parts by weight provides appropriate preservative and moisturizing effects simultaneously.

[0446] Phenoxyethanol is a colorless, transparent liquid, and 0.2 to 1 part by weight is weighed. Since this component is volatile, work quickly during weighing and handling, and use a sealed container. Phenoxyethanol has a distinctive odor, so use in excess should be avoided, and generally 0.5 to 0.8 parts by weight is appropriate.

[0447] Weigh the two preservatives together in a clean beaker or container and mix. Weigh 1,2-hexanediol first, then add phenoxyethanol, and mix by gently stirring with a glass rod or spatula. Since both components are liquids, they mix easily and uniformly. Place the mixed preservative in a container with a lid to prevent evaporation and keep it sealed until just before adding. Since it is preferable to add the preservative after the temperature of the formulation has dropped to 40°C or lower, it remains in a prepared state until it is added in step (f7).

[0448] (f4) Specific implementation method of step

[0449] Triethanolamine is a colorless, transparent, or pale yellow viscous liquid, and 0.01 to 1 part by weight is weighed. Since this component exhibits strong basicity, caution is required during handling, and direct contact with skin or eyes should be avoided. Because triethanolamine is hygroscopic and absorbs carbon dioxide, it should be stored in a sealed container and sealed immediately after use.

[0450] The amount of triethanolamine to be weighed is determined by the amount of carbomer used. Generally, 0.3 to 0.5 parts by weight of triethanolamine per 1 part by weight of carbomer is an appropriate neutralization ratio. However, it is desirable to prepare a slightly larger amount than required to account for the additional amount needed for final pH adjustment. The actual amount added is adjusted while measuring the pH in step (f8).

[0451] Triethanolamine can be prepared as a diluted solution by pre-mixing it with a small amount of purified water. For example, mixing 1 part by weight of triethanolamine with 9 parts by weight of purified water to create a 10% solution allows for more precise control when adjusting the pH. When preparing the diluted solution, triethanolamine is slowly added to the purified water while stirring with a glass rod. Caution is exercised during this process, as an exothermic reaction occurs. The prepared triethanolamine solution should be stored in a sealed plastic or glass container.

[0452] (f5) Specific implementation method of step

[0453] A thermometer is installed in the container holding the mixture prepared in the previous step (e), and the temperature of the mixture is checked. Since the temperature at the completion of step (e) is generally between 20°C and 30°C, it is heated to raise it to between 30°C and 50°C. Heating methods may include water bath heating, a mantle heater, or hot water circulation in a jacketed container. The heating rate is adjusted gradually to 1°C to 2°C per minute so that the temperature of the mixture rises uniformly.

[0454] When the temperature of the mixture reaches 30°C, the stirrer is activated to begin preliminary stirring at a speed of approximately 200 rpm. This is to equalize the temperature of the entire mixture and to prepare for the subsequent addition of the emulsifier. When the temperature reaches the target range of 30°C to 50°C, heating is controlled to maintain that temperature. Generally, 40°C to 45°C is the optimal emulsification temperature.

[0455] The prepared emulsifier mixture is added to a mixing container. If the emulsifier contains solid components, it is preferable to preheat it to 50°C to 60°C and add it in a completely melted state. Rather than adding the emulsifier all at once, it is added gradually over 2 to 5 minutes while increasing the stirring speed to 300 rpm. During addition, a spatula is used to assist to prevent the emulsifier from adhering to the walls of the container or the stirring blades.

[0456] Once the addition of the emulsifier is complete, the stirring speed is adjusted to 300 rpm to 500 rpm to proceed with full-scale emulsification. For the first 5 minutes, stirring is performed at an intermediate speed of 300 rpm to 400 rpm to disperse the emulsifier in the aqueous phase, and thereafter, the speed is increased to 400 rpm to 500 rpm to finely refine the emulsion particles and form a stable emulsion. During stirring, heating is controlled to maintain the temperature within the set range, and if excessive bubbles form on the surface, the depth of the stirring blades is adjusted or the speed is temporarily reduced.

[0457] During a stirring time of 10 to 20 minutes, samples are taken periodically to check the emulsification state. Spread the sample thinly on a glass slide and observe it under a microscope, or apply a small amount to the back of the hand and spread it to check for a uniform and smooth texture. If emulsification proceeds properly, the formulation becomes a uniform emulsion that is opaque white to cream-colored, and no separation of the oil and water phases is observed. Once emulsification is complete, prepare for the next step.

[0458] (f6) Specific implementation method of step

[0459] The stirring speed of the mixture after emulsification is completed is gradually reduced to between 200 rpm and 400 rpm. Since sudden changes in speed can shock the already formed emulsion structure, the speed is gradually reduced over 1 to 2 minutes. The temperature of the mixture is maintained within the range of 30°C to 50°C.

[0460] Add the prepared thickener powder mixture (carbomer and sodium acrylate / sodium acryloyl dimethyl taurate copolymer). Since adding the thickener all at once will form lumps, it must be added in divided portions. Divide the total thickener into 3 to 5 portions, with an interval of 3 to 5 minutes between each addition. During the first addition, sprinkle approximately 30% of the total amount evenly onto the liquid surface. When the thickener powder falls onto the liquid surface, it is gradually dispersed into the aqueous phase by stirring.

[0461] Immediately after adding the thickener, adjust the stirring speed to 250 rpm to 350 rpm to ensure the thickener is evenly dispersed. Slowly move the stirring blades up and down to ensure that all parts of the bottom, walls, and surface of the container are thoroughly stirred. After 3 to 5 minutes, add the second thickener and stir in the same manner. Repeat this process until all the thickener has been added.

[0462] Polyisobutene is added separately after the addition of the thickener powder is completed. Since polyisobutene has high viscosity, it is easier to disperse if mixed with a small amount of oil phase component (e.g., caprylyl / caprylglucoside) beforehand to lower the viscosity before addition. After addition, the mixture is stirred additionally at a speed of 200 to 300 rpm for 5 minutes to ensure uniform mixing.

[0463] After all thickeners have been added, the mixture is stirred continuously for 15 to 30 minutes. During this time, the carbomer and sodium acrylate / sodium acryloyldimethyltaurate copolymer hydrate and swell, causing the viscosity to gradually increase. During stirring, the walls and bottom of the container are periodically scraped with a spatula to remove any adhering material and ensure that the entire mixture is uniformly mixed. As the viscosity of the formulation increases over time and the stirring load becomes larger, the stirring speed may be slightly increased or a more powerful stirrer may be switched. At the completion of stirring, the formulation should be in the form of a smooth cream or gel, and no gel particles or lumps should be observed.

[0464] (f7) Specific implementation method of step

[0465] Check the temperature of the formulation in which the thickener is completely mixed. If the temperature is higher than 45°C, stop heating and allow it to cool naturally or circulate cold water to lower it to 40°C or lower. Although preservatives are heat-stable, volatilization increases at excessive temperatures, so it is advisable to add them at an appropriate temperature.

[0466] Reduce the stirring speed to 150 rpm to 300 rpm. Since the viscosity of the formulation has already increased significantly, mixing is insufficient at too low a speed, and the gel structure may be destroyed at too high a speed. Generally, 200 rpm to 250 rpm is appropriate.

[0467] The prepared preservative mixture (1,2-hexanediol and phenoxyethanol) is added to the formulation. Since the amount of preservative is small, it may be added all at once, but it can be added in two stages for more uniform dispersion. When adding, the container is rotated to disperse the mixture into various locations within the formulation.

[0468] After adding the preservative, stir at a speed of 150 to 300 rpm for 5 to 15 minutes. This time is sufficient for the preservative to be uniformly dispersed throughout the formulation. During stirring, scrape the walls and bottom of the container with a spatula to prevent localized concentration of the preservative. Once the preservative is completely mixed, the characteristic odor of the preservative should be uniformly detected in the formulation, and the color and texture should be uniform when a sample is taken and observed.

[0469] (f8) Specific implementation method of step

[0470] Measure the pH of the formulation while maintaining continuous stirring. Use the pH meter electrode after calibrating it with a calibration solution (pH 4.0, 7.0, 10.0). Since the viscosity of the formulation is high, insert the pH electrode deeply into the formulation and wait for a sufficient amount of time (30 seconds to 1 minute) to obtain a stable measurement value. Check for uniformity by measuring the pH in various parts of the formulation (top, middle, and bottom).

[0471] If the measured pH is less than 5.0, triethanolamine is added in small amounts to raise the pH. If the triethanolamine is in pure form, 0.1 mL to 0.5 mL is added using a dropper or pipette, and if it is a 10% aqueous solution, 0.5 mL to 2 mL is added. After each addition, the mixture is stirred for 5 to 10 minutes to ensure that the triethanolamine is uniformly mixed and the neutralization reaction of the carbomer is completed.

[0472] When triethanolamine is added, the viscosity of the formulation increases rapidly as the carbomer is neutralized. This is because the carboxyl groups of the carbomer are neutralized, causing the polymer chains to elongate and absorb water to form a gel network. Therefore, the addition of triethanolamine must be carried out cautiously while monitoring changes in the viscosity of the formulation. Excessive neutralization increases viscosity excessively, making handling difficult in subsequent processes.

[0473] When the pH reaches the target range of 5.0 to 6.5, stop further addition and continue stirring for 10 minutes. Afterward, measure the pH again to check if the value remains stable. Although it is rare for the pH to exceed 6.5, if it does, the pH can be lowered by adding small amounts of an aqueous solution of a weak acid, such as citric acid or lactic acid. When the final pH is in the range of 5.5 to 6.0, a formulation is completed that is skin-friendly while optimizing peeling and moisturizing effects.

[0474] (f9) Specific implementation method of step

[0475] Check the temperature of the pH-adjusted formulation. At this point, the temperature is generally in the range of 35°C to 45°C. Stop heating and start cooling to cool the formulation to 20°C to 30°C. Cooling methods include circulating cold water outside the container, immersing the container in a cold water bath, or using a cooling coil. The cooling rate should be controlled gradually at 0.5°C to 1°C per minute to avoid thermal shock to the formulation.

[0476] As cooling begins, reduce the stirring speed to 100 to 200 rpm. A low stirring speed ensures that the temperature is distributed evenly while maintaining the structure of the formulation. Rotate the stirring blades slowly to ensure that the entire formulation cools evenly. Exercise caution, as excessive stirring can destroy the already formed emulsion structure and gel network.

[0477] During cooling, the cooling rate is monitored by measuring the temperature of the formulation at 5-minute intervals. When the temperature approaches 30°C, the cooling rate is further reduced to prevent excessive cooling. During the cooling process, an additional increase in the viscosity of the formulation can be observed. This is a normal phenomenon resulting from the decrease in temperature and is a process in which the structures of the emulsifier and thickener are stabilized.

[0478] Cooling is stopped when the temperature of the formulation reaches the range of 20°C to 30°C. Generally, 25°C to 28°C is the ideal temperature for the final formulation. At this temperature, final stirring is performed for 10 to 20 minutes at a speed of 100 rpm to 200 rpm. This step is a finishing process that ensures the temperature of the formulation is completely uniform and that all ingredients are stably dispersed.

[0479] Once final stirring is complete, stop stirring and visually inspect the formulation. The formulation must be a uniform white to cream-colored opaque cream or lotion and must be free from defects such as phase separation, precipitation, bubbles, or color non-uniformity. Take a small sample, apply it to the back of the hand, and spread it to check the texture. The formulation should spread smoothly, have minimal stickiness, and provide a moist and fresh feeling after absorption into the skin.

[0480] For quality inspection, the viscosity of the formulation is measured using a Brookfield viscometer, the pH is reconfirmed, and, if necessary, the size and distribution of emulsion particles are observed under a microscope. Once all quality standards are met, the formulation is transferred to a filling container to proceed with the filling process, or placed in a sealed stainless steel container and filled within 24 hours. Until filling, it is stored at room temperature, avoiding direct sunlight. This completes the manufacture of a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling.

[0481] The technical reasons, critical significance, and specific implementation methods of the above steps (g) and (g1) to (g8) are as follows.

[0482] Technical reasons for the homogenization step and the critical significance of the numerical range

[0483] (g2) Step: Maintain homogenization temperature

[0484] Performing the homogenization process within a temperature range of 25°C to 35°C is an essential condition for simultaneously achieving physical stability of the cosmetic composition and preserving the activity of the active ingredients. If the temperature is below 25°C, the viscosity of the composition increases excessively, which lowers homogenization efficiency, reduces the emulsifying ability of the emulsifier, and poses a risk of some components crystallizing or precipitating. In particular, higher alcohol components such as cetearyl alcohol can solidify at low temperatures to form particles, which degrades the texture and appearance of the product.

[0485] On the other hand, if the temperature exceeds 35℃, the physiological activity of heat-sensitive peptides, enzyme peeling agents, natural moisturizing factors, and hydrangenol contained in hydran extract may decrease. According to clinical studies, hydrangenol activates the AP-1 pathway and the Akt / PI3K pathway to increase the expression of hyaluronic acid synthase, and this physiological activity tends to decrease as the temperature rises. Furthermore, at high temperatures, the emulsion structure becomes unstable, the loss of volatile components increases, and the risk of microbial growth increases. The range of 25℃ to 35℃ is the optimal temperature range that can preserve the stability and activity of all components while maintaining the fluidity of the composition appropriately.

[0486] (g3) Step: 1st Homogenization - Homomicker

[0487] In the primary homogenization using a homomixer, processing at a rotational speed of 3,000 to 6,000 rpm for 5 to 15 minutes is a step intended to ensure macroscopic uniformity and disperse large particles or lumps. If the rotational speed is less than 3,000 rpm, the shear force is insufficient, resulting in incomplete mixing between components, ineffective placement of emulsifiers at the interface between the oil and water phases, and the persistence of local concentration differences, which degrades the uniformity of the product. In particular, high-viscosity thickeners or solid components may not be completely dispersed, leaving behind particles or lumps.

[0488] On the other hand, speeds exceeding 6,000 rpm can cause the emulsion structure to be destroyed due to excessive shear force, excessive air incorporation leading to foaming, and structural damage to some components. In particular, peptide or protein components may be denatured by excessive shear force, and the emulsion stability may actually decrease as the size of the emulsion particles becomes too small. The range of 3,000 rpm to 6,000 rpm is a critical range that provides appropriate shear force to achieve macroscopic uniformity while minimizing damage to components.

[0489] The processing time of 5 to 15 minutes is a range that takes into account the amount, viscosity, and composition of the components. Processing for less than 5 minutes results in incomplete homogenization and insufficient mixing of the components, while processing for more than 15 minutes provides minimal additional homogenization effects, increases energy consumption, and raises the risk of component damage and temperature rise due to excessive shear. Since mechanical friction caused by the rotation of the homomixer blades can raise the temperature of the composition, the need for a cooling device increases as the processing time lengthens.

[0490] (g4) Step: Secondary Homogenization - High-shear Homogenizer

[0491] In secondary homogenization using a high-shear homogenizer, processing at a speed of 8,000 to 12,000 rpm for 10 to 20 minutes is a key step for ensuring microscopic uniformity and refining particle size. The high-shear homogenizer applies extremely high shear force while passing the composition through a narrow gap between the stator and the rotor to finely grind the particles and reduce the size of the emulsion particles.

[0492] If the rotation speed is less than 8,000 rpm, the shear force is insufficient, resulting in inadequate particle refinement and a widening of the emulsion particle size distribution, which lowers product stability and skin absorption rate. Large particles or aggregates formed during the first homogenization are not completely dispersed, which may cause a gritty texture or separation in the final product. In particular, if various peeling active ingredients and complex moisturizing ingredients for low-irritation peeling are not uniformly dispersed, the reproducibility of the product's efficacy is reduced.

[0493] Conversely, speeds exceeding 12,000 rpm cause problems such as destruction of emulsion structures, denaturation of peptide or enzyme components, oxidation of retinol derivatives, and excessive heat generation due to excessive shear force. As reported in clinical papers, since the effect of hydrangenol activation via the MAPK pathway depends on the integrity of the molecular structure, structural changes caused by excessive shear force lead to a decrease in physiological activity. The range of 8,000 to 12,000 rpm is the optimal range that can effectively micronize particles while preserving the structural integrity of physiologically active components.

[0494] A processing time of 10 to 20 minutes is the time required to reach the target particle size. Processing for less than 10 minutes results in incomplete particle refinement, while processing for more than 20 minutes results in minimal further reduction in particle size, whereas the risk of temperature rise due to exothermic reaction and component damage increases. During high-shear homogenization, the temperature of the composition must be continuously monitored and a cooling device operated to maintain the set temperature range.

[0495] (g5) Step: Tertiary Homogenization - High-pressure Homogenizer

[0496] Passing the composition through a high-pressure homogenizer three to four times under pressure conditions of 80 to 150 bar is the final homogenization step for nano-level particle refinement and ensuring long-term stability. The high-pressure homogenizer grinds the particles to an extremely fine level by applying complex physical forces such as cavitation, turbulence, and collision while passing the composition through a very narrow valve or orifice at high pressure.

[0497] If the pressure is less than 80 bar, the particle micronization effect is insufficient, so the average particle size of the final product may deviate from the target range of 0.1 μm to 5 μm, and the wide size distribution of emulsion particles may lead to particle aggregation or creaming during long-term storage. In particular, if hyaluronic acid of various molecular weights and complex peptides are not uniformly dispersed, the skin absorption efficiency is reduced and the reproducibility of efficacy decreases.

[0498] On the other hand, pressures exceeding 150 bar cause problems such as destruction of the emulsion structure, temperature rise, and physicochemical denaturation of components due to excessive energy input. In particular, natural components such as hydranzenol from hydrangea extract and plant collagen precursors may undergo structural changes or reduced activity due to extreme physical stress. The pressure range of 80 to 150 bar is a critical range that allows for the preservation of the integrity of physiologically active components while achieving nano-level particle refinement.

[0499] Setting the number of repeated passes to 3 to 4 is the result of simultaneously considering particle size uniformity and process efficiency. Passing fewer than 3 times does not ensure particle size uniformity, resulting in the retention of some large particles; if it exceeds 4 times, while the additional reduction in particle size is minimal, process time and energy consumption increase, and the risk of component damage increases. After each pass, the temperature of the composition is cooled to 25°C to 35°C before proceeding with the next pass to prevent heat accumulation.

[0500] (g6) Step: Particle size measurement and adjustment

[0501] Managing the average particle size within the range of 0.1 μm to 5 μm is an essential condition for optimizing the product's skin absorption rate, stability, and user experience. If the particle size is less than 0.1 μm, the particles are excessively fine, making them thermodynamically unstable and prone to aggregation, which may increase the risk of skin irritation from certain active ingredients. Furthermore, nano-sized particles pose a risk of penetrating deep into the skin and inducing unexpected biological reactions.

[0502] On the other hand, if the particle size exceeds 5 μm, the skin absorption rate decreases, a gritty texture is felt upon application, and product stability is compromised due to sedimentation or creaming during long-term storage. Clinical studies have shown that a cream containing hydrangea extract increased skin hydration and reduced wrinkle depth after 4 weeks of use, which is attributed to the effective absorption of active ingredients into the skin through proper particle size management. The range of 0.1 μm to 5 μm is the critical range that allows for the simultaneous achievement of optimal absorption through the stratum corneum and long-term stability.

[0503] The specification of measurement conditions—a temperature of 25°C, the use of purified water as a dispersion medium, and ultrasonic treatment for 3 minutes—is intended to ensure the reproducibility and accuracy of the measurement. Since temperature affects particle size and dispersion state, it must be maintained constant, and purified water provides an environment most similar to that of a cosmetic composition. Ultrasonic treatment disperses aggregated particles, allowing for the measurement of primary particle size, and treatment for 3 minutes is the optimal time to achieve sufficient dispersion while preventing particle destruction.

[0504] (g7) Step: Viscosity measurement and adjustment

[0505] Managing viscosity within the range of 10,000 to 25,000 cps is an essential condition for optimizing the product's feel, stability, and efficacy delivery. If the viscosity is less than 10,000 cps, the composition becomes excessively thin, causing it to run off upon application to the skin; the retention time of active ingredients on the skin is short, leading to reduced efficacy; and emulsion stability is lowered, which may result in phase separation. In particular, if AHA, BHA, PHA, and enzyme peeling agents for a low-irritation peeling effect do not contact the skin for a sufficient amount of time, the exfoliation effect is reduced.

[0506] On the other hand, if the viscosity exceeds 25,000 cps, the composition becomes excessively sticky and thick, making it difficult to spread on the skin, resulting in slow absorption, and lowering consumer satisfaction due to a stuffy sensation. Furthermore, excessive viscosity can physically hinder the skin penetration of active ingredients, potentially reducing efficacy. Considering that clinical studies aimed for a lightweight, daily-use formulation to develop a product for daily home care, proper viscosity management is essential to encourage continued consumer use.

[0507] The range of 10,000 to 25,000 cps is a critical range that can optimize the delivery efficiency of active ingredients while providing appropriate fluidity and skin adhesion as a cream-type cosmetic. This viscosity range allows for light application as an ampoule-type formulation while providing sufficient moisturizing and elasticity-enhancing effects.

[0508] The specification of measurement conditions—a Brookfield rotational viscometer, 20°C, spindle No. 5, 12 rpm, and a measurement for 1 minute—is intended to ensure the standardization and reproducibility of the measurement. The Brookfield rotational viscometer is the most widely used viscosity measuring instrument in the cosmetics industry, and standard methods have been established. 20°C is a room temperature condition similar to actual usage environments, and the conditions of spindle No. 5 and 12 rpm are standard conditions suitable for measuring the viscosity of cream-type cosmetics. The measurement time of 1 minute is the minimum time required for stabilizing the viscometer and obtaining accurate measurement values.

[0509] Specific implementation methods for each step

[0510] (g1) Specific implementation method of step

[0511] Before introducing the cosmetic composition into the homogenization device, the condition of the composition is visually inspected. It is checked whether the composition is uniformly mixed, whether there are any precipitates or aggregates, and whether there is any separation between the oil and water phases. If any abnormalities are found, the composition is re-stirred at a low speed before introduction to restore uniformity.

[0512] Before use, the homogenizing device should be cleaned and dried to ensure there are no residues or contaminants from the previous batch. Verify that all parts of the device are functioning properly, and inspect the condition of parts in direct contact with the composition, in particular, such as the blades of the homomixer, the stator and rotor of the high-shear homogenizer, and the valve of the high-pressure homogenizer. Replace any worn or damaged parts.

[0513] The amount of the composition to be added is determined by considering the capacity of the homogenization device. Generally, it is appropriate to add 60% to 80% of the device capacity; excessive addition reduces homogenization efficiency, while insufficient addition reduces equipment usage efficiency. The composition is added slowly through the inlet of the device, and rapid addition should be avoided as it may cause air to be mixed in.

[0514] After addition, preliminary stirring is performed at a low speed so that the composition is evenly distributed inside the device. This is a process to equalize the temperature of the composition and remove large bubbles before full-scale homogenization. Preliminary stirring is performed for 1 to 3 minutes at a low speed of 500 rpm to 1,000 rpm.

[0515] (g2) Specific implementation method of step

[0516] The homogenization device must be equipped with a temperature control system. Generally, a double-jacketed container is used, and cooling water or hot water is circulated inside the jacket to control the temperature of the composition. The cooling water circulation device uses a thermostat or a chiller, and circulates cooling water at a temperature 5 to 10°C lower than the set temperature.

[0517] The temperature of the composition is monitored in real time through a temperature sensor inserted inside the device. The temperature sensor is installed at least two points, one at the center of the composition and one near the surface, to verify the uniformity of the temperature distribution. Temperature data is recorded using a digital thermometer or a data logger, and measurements are taken at one-minute intervals to identify the trend of temperature changes.

[0518] During the homogenization process, the temperature of the composition may rise due to mechanical friction and shear heat. If the temperature approaches or exceeds 35°C, homogenization is immediately suspended, and the composition is cooled to 25°C to 30°C by increasing the flow rate of the cooling water or lowering the temperature. During cooling, stirring is continued at a low speed to ensure that the temperature of the composition is lowered uniformly. Homogenization is resumed when the target temperature is reached.

[0519] In particular, since significant heat generation occurs during the high-shear and high-pressure homogenization stages, the temperature is managed by allowing sufficient cooling time between each stage. When using a continuous high-pressure homogenizer, a heat exchanger can be installed to cool the composition immediately after passing through it. Since product quality deteriorates if the temperature exceeds 35°C due to improper temperature control, efforts should be made to record and minimize the time exceeding the temperature.

[0520] (g3) Specific implementation method of step

[0521] A homomixer is equipment that achieves simultaneous mixing and dispersion by using high-speed rotating blades to vigorously agitate a composition. Homomixer blades generally come in various forms, such as turbine, propeller, or disc types, and the appropriate type is selected based on the viscosity and characteristics of the composition. Turbine-type blades are suitable for cream-type cosmetics.

[0522] Before operating the homomixer, ensure that the blades are completely submerged in the composition. If the blades are exposed above the liquid surface, excessive air will be incorporated and splashing will occur. Increase the rotation speed of the homomixer in stages. Start at a low speed of about 1,000 rpm, and after confirming that the composition is being stably stirred, gradually increase the speed to reach the final target speed of 3,000 to 6,000 rpm. A sudden increase in speed will cause scattering of the composition or excessive bubble generation.

[0523] Homogenization is carried out for 5 to 15 minutes at the target speed. During homogenization, the condition of the composition is observed periodically. If the color of the composition becomes uniform, gloss develops, and no lumps or aggregates are observed, homogenization is proceeding properly. If the composition is stagnant on the walls or bottom of the container, the position of the blade is adjusted or the container is tilted to ensure that the entire composition is homogenized.

[0524] Bubbles generated during homogenization should be minimized as much as possible. If excessive bubbles occur, reduce the rotation speed or adjust the blade depth. After homogenization is complete, gradually reduce the rotation speed until it comes to a stop. Sudden stopping can shock the composition and alter its structure. The composition after the first homogenization must be in a uniform cream state when observed with the naked eye, and no distinct particles or lumps should be visible.

[0525] (g4) Specific implementation method of step

[0526] A high-shear homogenizer is equipment that applies extremely high shear force while passing a composition through a narrow gap between a high-speed rotating rotor and a stationary stator. The gap between the rotor and the stator is generally 0.1 mm to 0.5 mm, and as the composition passes through this narrow gap, it experiences strong shear, compression, and collision, causing the particles to be finely ground.

[0527] The primary homogenized composition is fed into or transferred to a high-shear homogenizer. When using a batch-type high-shear homogenizer, the composition is transferred to the equipment's container, and when using an inline-type, the composition is continuously supplied using a pump. The rotor rotation speed of the high-shear homogenizer is gradually increased to reach a target speed of 8,000 rpm to 12,000 rpm. A sudden increase in speed overloads the equipment and causes scattering of the composition.

[0528] Homogenization is performed for 10 to 20 minutes at the target speed. In the case of the batch type, the composition is gradually refined as it repeatedly passes between the rotor and the stator. In the case of the inline type, the pump flow rate is adjusted so that the composition passes through at a constant speed. The temperature of the composition is continuously monitored during homogenization. Since high-shear homogenization generates significant heat, a cooling device is operated to ensure that the temperature does not exceed 35°C.

[0529] The progress of homogenization can be confirmed through changes in the appearance of the composition. If the gloss of the composition increases, the texture becomes smoother, and the color becomes more uniform, homogenization is proceeding effectively. If necessary, a small sample can be taken in the middle to observe the particle condition under a microscope or perform a simple particle size measurement to check whether the target particle size is being approached.

[0530] Once homogenization is complete, the rotation speed of the rotor is gradually reduced and stopped. The secondary homogenized composition has a finer and more uniform texture than the primary homogenized product and exhibits the characteristic of spreading smoothly when applied to the skin. The composition is transferred or prepared for the next step, high-pressure homogenization.

[0531] (g5) Specific implementation method of step

[0532] A high-pressure homogenizer is equipment that pressurizes a composition with a high-pressure pump and causes a rapid pressure drop as it passes through a very narrow valve or orifice. During this process, complex physical phenomena such as cavitation, turbulence, and high-speed collisions occur, thereby miniaturizing the particles to the nano level.

[0533] The secondary homogenized composition is introduced into the supply tank of a high-pressure homogenizer. The supply tank is equipped with a stirring device to continuously stir the composition so that it does not settle or separate. A high-pressure pump is operated to pressurize the composition. The pressure is increased in steps until it finally reaches a target pressure of 80 to 150 bar. Generally, it is appropriate to select an intermediate pressure of 100 to 120 bar.

[0534] The composition experiences a rapid pressure drop as it passes through a homogenization valve under high pressure. The valve gap is very narrow, at the level of tens of micrometers, and the composition passes through this narrow gap at a speed of hundreds of meters per second. Immediately after passing through, as the pressure drops rapidly, a cavitation phenomenon occurs in which bubbles form and collapse within the liquid, and the shock waves at this time finely pulverize the particles.

[0535] After passing through once, the composition passes through a cooler to lower the temperature to 25°C to 30°C. Immediate cooling is required because the temperature of the composition rises due to frictional heat generated during the high-pressure homogenization process and the conversion of pressure energy. The cooled composition is returned to the supply tank or collected in a separate container and re-introduced to proceed with the second pass.

[0536] The material is passed through a total of 3 to 4 times under the same pressure conditions. With each pass, the particles become finer and the size distribution narrows. After the third pass, check whether the particle size has reached the target range of 0.1 μm to 5 μm, and if necessary, perform a fourth pass. Excessive repetition is not performed more than 4 times, as it has minimal effect and poses a risk of damaging the material.

[0537] After final passage, the composition is sufficiently cooled, and then a sample is taken for the next step, particle size measurement. The composition, having undergone high-pressure homogenization, has a very fine and uniform texture, exhibits excellent gloss, and shows the characteristic of being immediately absorbed upon application to the skin.

[0538] (g6) Specific implementation method of step

[0539] Particle size measurement utilizes a particle size analyzer employing the laser diffraction method. Laser diffraction is a standard method widely used in the cosmetics industry that calculates the particle size distribution by measuring the angle and intensity of laser light scattered by particles.

[0540] Sample preparation for measurement is carried out as follows. Purified water, heated to 25°C, is used as a dispersion medium and filled into the measurement cell of the particle size analyzer. A small amount of the cosmetic composition, after tertiary homogenization, is taken and added to the dispersion medium. The amount added is adjusted so that the light shielding degree of the particle size analyzer falls within the range of 10% to 20%. If the light shielding degree is too low, measurement accuracy decreases, and if it is too high, multiple scattering occurs, increasing measurement error.

[0541] After introducing the sample, ultrasonic treatment is performed for 3 minutes using an ultrasonic generator. Ultrasonic treatment disperses aggregated particles, allowing the size of the primary particles to be measured. The ultrasonic output is set to an intermediate level, as excessive output can destroy the particles. During ultrasonic treatment, the measurement cell is stirred with a circulation pump to ensure that the sample is uniformly dispersed.

[0542] Laser diffraction measurements are started immediately after ultrasonic processing is complete. The measurement time is typically 1 to 3 minutes, during which thousands to tens of thousands of particle data are collected. Once the measurement is complete, the particle size analyzer software calculates the particle size distribution and displays the average particle size. For the average particle size, the average diameter by volume D[4,3] or the median diameter D50 is typically used.

[0543] If the average particle size is within the range of 0.1 μm to 5 μm as a result of measurement, the particle size is determined to be suitable. The particle size distribution is also checked to evaluate whether the distribution is narrow and exhibits a single peak. A double peak or a wide distribution indicates that homogenization is incomplete or aggregation has occurred.

[0544] If the average particle size exceeds 5 μm, the high-pressure homogenization step is repeated one or two additional times. During additional homogenization, the same pressure conditions may be maintained, or the pressure may be increased to 10 bar to 20 bar if necessary. After each additional homogenization, the particle size is measured again to check if it has reached the target range. Although it is rare for the average particle size to be less than 0.1 μm, if it occurs, it indicates that the homogenization conditions were excessive, so the pressure is lowered or the number of passes is reduced in the next batch.

[0545] Particle size measurements are repeated at least three times to obtain the average value and standard deviation. Once the reproducibility of the measurements is ensured, particle size management is deemed complete, and the process proceeds to the next step, viscosity measurement.

[0546] (g7) Specific implementation method of step

[0547] Viscosity measurement is performed using a Brookfield rotational viscometer. The Brookfield viscometer is an instrument that calculates viscosity by measuring the resistance as the spindle rotates within the sample; due to its ease of use and excellent reproducibility, it is used as the standard measurement method in the cosmetics industry.

[0548] Sample preparation for measurement is carried out as follows. Place the cosmetic composition with confirmed particle size into a suitable container. A 600 mL beaker is generally used for Brookfield viscometer measurements. Fill the beaker with approximately 500 mL of the sample, but add an amount sufficient so that the spindle is completely submerged and does not touch the walls or bottom when rotated.

[0549] Adjust the temperature of the sample to 20℃. Since temperature significantly affects viscosity, it must be managed accurately. Leave the sample in a 20℃ constant temperature bath for at least 30 minutes to ensure the temperature is uniformly adjusted throughout. Alternatively, insert a thermometer into the sample to confirm that it has reached 20℃.

[0550] Mount Spindle No. 5 on the Brookfield viscometer. The selection of the spindle is determined by the expected viscosity range, and Spindle No. 5 is suitable for cream-type cosmetics in the range of 10,000 to 25,000 cps. Insert the spindle vertically into the center of the sample, ensuring it is submerged up to the immersion line marked on the spindle. Adjust the position so that the spindle does not touch the walls or bottom of the beaker.

[0551] Set the rotation speed of the viscometer to 12 rpm. 12 rpm is a standard speed suitable for measuring the viscosity of cream-type cosmetics. Operate the viscometer to rotate the spindle and conduct measurements for 1 minute. Since the initial 30 seconds are the time required for the sample structure to stabilize, record the viscosity value after 30 seconds. In the case of a digital viscometer, the stabilized value is automatically displayed.

[0552] Once the measurement is complete, record the viscosity value displayed on the viscometer. Use the unit cps or mPa·s. If the measured viscosity is within the range of 10,000 cps to 25,000 cps, the viscosity is determined to be acceptable. Viscosity measurements are repeated at least three times to obtain the average value, and reproducibility is determined to be ensured when the deviation of the measured value is within 5%.

[0553] If the measured viscosity is less than 10,000 cps, a thickening agent is added to increase the viscosity. Carbomer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer, or polyisobutene may be used as the thickening agent. The amount of the thickening agent added is small, ranging from 0.05% to 0.2% of the total weight of the composition. After each addition, the mixture is blended with a homomixer for 5 to 10 minutes to completely disperse the thickening agent, after which the viscosity is measured again. This process is repeated until the target viscosity range is reached.

[0554] Viscosity generally does not exceed 25,000 cps, but if it does, dilute by adding a small amount of purified water or reduce the amount of thickener in the next batch. Once viscosity adjustment is complete, finally re-measure the viscosity to confirm that it is within the target range.

[0555] (g8) Specific implementation method of step

[0556] Once it is confirmed that both particle size and viscosity are within the target range, the final cosmetic composition is filled into a container. Before filling, the following items are checked to verify the final quality of the composition. The appearance must be a uniform cream state with no visible particles or lumps, and it must be glossy and have a uniform color. The odor must be free of off-flavors and have the natural scent of the raw materials. The pH is checked using a pH meter to ensure it is within the range of 5.0 to 6.5.

[0557] Filling containers are selected according to the product's intended use and marketing plan. Pump containers, tube containers, or airless containers are suitable for daily home care products. Containers should be washed and dried before use, and UV sterilization or alcohol disinfection should be performed if necessary. The container material should be selected to ensure it does not react with the cosmetic composition and can stably protect the contents.

[0558] Filling operations should be performed in a clean environment. To prevent microbial contamination, work should be done within a clean room or clean bench whenever possible. When using an automatic filling machine, the filling amount should be set accurately; for manual filling, the exact weight or volume should be measured. Care should be taken to prevent air bubbles from being introduced during filling, and the opening of the container should be finished cleanly to ensure no contents adhere to it.

[0559] Seal the container after filling. Assemble the pump for pump-type containers, attach the cap for tube-type containers, and assemble the disc and cap for airless containers. To verify the seal's integrity, invert the container or shake it to check for any leakage. After filling is complete, wipe the outside of the container clean to ensure no contents remain on it.

[0560] Labels are affixed to the final product. The label displays all legally required information, such as the product name, manufacturing date, expiration date, full list of ingredients, net weight, manufacturer information, usage instructions, and precautions. In particular, product features, such as hydrangea extract content, low-irritation peeling effect, and moisturizing and elasticity-enhancing effects, are indicated in a way that is easy for consumers to understand.

[0561] Store the filled product in a suitable packaging box. Storage conditions should be a cool place away from direct sunlight, maintaining a temperature of 5°C to 25°C and a humidity of 60% or less. The product typically has a shelf life of 3 years from the date of manufacture, but it is recommended to use it within 6 to 12 months after opening.

[0562] Stability tests are conducted on the final product. Room temperature stability tests are performed at 25°C for 3 months, with appearance, pH, viscosity, particle size, and microbial limit tests conducted at 1-month intervals. Harsh condition stability tests are performed at 40°C and 4°C for 1 month each, while testing the same items. If all stability test results meet the standards, the final product is deemed complete and its shipment is approved.

[0563] In addition, the present invention relates to a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling, and is manufactured by a method for manufacturing a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling.

[0564] Hereinafter, the structure of the present invention and the resulting effects will be explained in more detail through specific embodiments and comparative examples. However, these embodiments are intended to explain the present invention more specifically, and the scope of the present invention is not limited to these embodiments.

[0565] [Example 1]

[0566] Hydrangea extract preparation

[0567] Hydrangea leaf raw material was prepared by washing the hydrangea leaves and then hot-air drying them at 50°C for 18 hours. 1500 g of purified water was added to 100 g of the hydrangea leaf raw material. The mixture was subjected to hot water extraction at 98°C for 5 hours to obtain an extract. The extract was filtered through a membrane filter with a pore size of 10 μm to obtain a filtrate. The filtrate was concentrated using a vacuum concentrator at a temperature of 70°C under a reduced pressure of 0.05 MPa to obtain a concentrate. The concentrate was spray-dried under conditions of an inlet temperature of 165°C and an outlet temperature of 90°C to obtain 120 g of hydrangea extract powder. The hydrangenol content in the hydrangea extract powder was analyzed by liquid chromatography and confirmed to be 1.2 wt%.

[0568] Preparation of peeling active ingredient mixture

[0569] 0.5 g of glycolic acid, 0.4 g of lactic acid, 0.3 g of mandelic acid, and 0.2 g of citric acid were dissolved in 48.6 g of purified water, and 0.5 g of salicylic acid, 1.5 g of gluconolactone, 0.1 g of papain, 0.08 g of bromelain, 0.08 g of pumpkin enzyme, and 0.05 g of pineapple enzyme were sequentially added to the mixture and mixed at a speed of 300 rpm for 20 minutes to prepare 52.31 g of a peeling active ingredient mixture. The pH of the peeling active ingredient mixture was 4.2.

[0570] Preparation of moisturizing ingredient mixtures

[0571] 0.8 g of low molecular weight hyaluronic acid (molecular weight 5 kDa), 0.6 g of medium molecular weight hyaluronic acid (molecular weight 50 kDa), and 0.4 g of high molecular weight hyaluronic acid (molecular weight 800 kDa) were dissolved in 20 g of purified water and stirred at 300 rpm for 1 hour at 30°C. To this, 5.0 g of glycerin, 3.0 g of butylene glycol, 2.0 g of dipropylene glycol, 0.3 g of sodium pyrrolidone carboxylate, 0.2 g of serine, 0.2 g of glycine, 0.15 g of alanine, 0.15 g of arginine, and 0.1 g of proline were sequentially added and mixed at 300 rpm for 15 minutes at 30°C to prepare a moisturizing ingredient mixture of 32.9 g.

[0572] Preparation of a mixture of elasticity-enhancing ingredients

[0573] 0.05 g of palmitoyl pentapeptide-4, 0.04 g of palmitoyl tripeptide-1, 0.03 g of palmitoyl tetrapeptide-7, 0.04 g of acetyl hexapeptide-8, 0.03 g of copper tripeptide-1, and 0.02 g of carnosine were dissolved in 5 g of purified water and ultrasonically treated for 10 minutes to prepare a peptide solution. To this, 0.04 g of adenosine, 0.02 g of retinol, 0.03 g of retinyl palmitate, 2.0 g of Centella asiatica extract, 1.5 g of red ginseng extract, 1.0 g of green tea extract, 0.8 g of aloe vera extract, and 0.5 g of licorice extract were sequentially added and mixed at 25°C at a speed of 250 rpm for 20 minutes to prepare 11.09 g of a mixture of elasticity-enhancing ingredients.

[0574] Preparation of cosmetic compositions

[0575] A mixing container was prepared and maintained at 25℃. 25.0 g of the moisturizing ingredient mixture was added to the mixing container and stirred for 10 minutes at a speed of 200 rpm. A hydrangea extract solution, prepared by dissolving 15.0 g of the hydrangea extract powder in 50 g of purified water, was added dropwise over 5 minutes while stirring for 15 minutes at a speed of 350 rpm. To the mixture stirred for the second time, 8.0 g of the peeling active ingredient mixture was added dropwise over 5 minutes while stirring for 15 minutes at a speed of 250 rpm. To the mixture stirred for the third time, 10.0 g of the elasticity-enhancing ingredient mixture was added dropwise over 5 minutes while stirring for 20 minutes at a speed of 350 rpm. The mixture stirred for the fourth time was degassed using a vacuum degasser under a vacuum condition of 0.03 MPa for 10 minutes to produce a mixture of 108.0 g.

[0576] To the above mixture, 1.5 g of cetearyl alcohol, 1.0 g of glyceryl stearate, 1.0 g of PEG-100 stearate, 0.8 g of sorbitan oleate, and 0.8 g of caprylyl / capryl glucoside were added and stirred at 400 rpm for 15 minutes at 40°C. Then, 0.8 g of carbomer, 0.5 g of sodium acrylate / sodium acryloyl dimethyl taurate copolymer, and 0.3 g of polyisobutene were added and stirred at 300 rpm for 20 minutes. Subsequently, 1.2 g of 1,2-hexanediol and 0.6 g of phenoxyethanol were added and stirred at 250 rpm for 10 minutes. After measuring the pH of the mixture, triethanolamine was added dropwise to adjust the pH to 5.6. A cosmetic composition of 116.5 g was prepared by cooling the above pH-adjusted mixture to 25°C and stirring it for 15 minutes at a speed of 150 rpm.

[0577] The above cosmetic composition was introduced into a homogenization device and first homogenized for 10 minutes at a speed of 4,500 rpm using a homomixer while maintaining the temperature at 30°C. The first homogenized composition was secondarily homogenized for 15 minutes at a speed of 10,000 rpm using a high-shear homogenizer. The secondly homogenized composition was thirdly homogenized by passing it through a high-pressure homogenizer three times under a pressure of 100 bar. The particle size of the thirdly homogenized composition was measured, and it was confirmed that the average particle size was 2.1 μm. The viscosity of the composition was measured, and it was confirmed to be 15,500 cps. The composition was filled into a container to obtain a final cosmetic composition of 115.8 g.

[0578] [Comparative Example 1]

[0579] A cosmetic composition of 113.2 g was prepared by the same method as in Example 1, but without using 15.0 g of hydrangea extract powder and replacing it with 15.0 g of purified water.

[0580] [Comparative Example 2]

[0581] The peeling active ingredient mixture was prepared using the same method as in Example 1, except that 0.5 g of glycolic acid, 0.4 g of lactic acid, 0.3 g of mandelic acid, and 0.2 g of citric acid were not used, and only 3.5 g of glycolic acid was used. The remaining 114.6 g of the cosmetic composition was prepared using the same method as in Example 1.

[0582] [Comparative Example 3]

[0583] A cosmetic composition of 112.8 g was prepared by the same method as in Example 1, but without using the elasticity-enhancing ingredient mixture and replacing it with 10.0 g of purified water.

[0584] [pH Measurement Experiment]

[0585] 50 g of each cosmetic composition prepared in Example 1 and Comparative Examples 1 to 3 was placed in a beaker and left to stand at a temperature of 25°C for 30 minutes. A pH measuring electrode was inserted to a depth of 5 cm into the center of the composition and stabilized for 5 minutes, after which the pH value was measured. For each composition, the measurement was repeated three times to calculate the mean value and standard deviation. After the measurement, the electrode was washed with purified water and recalibrated with a standard buffer solution, after which the next sample was measured.

[0586] division pH (mean ± standard deviation) Whether the weakly acidic range (pH 5.0-6.5) is met Example 1 5.58 ± 0.04 Satisfaction Comparative Example 1 5.62 ± 0.05 Satisfaction Comparative Example 2 3.78 ± 0.06 Unsatisfied Comparative Example 3 5.54 ± 0.03 Satisfaction

[0587] The cosmetic composition of Example 1 exhibited a pH of 5.58, which corresponds to the skin's natural pH range of 5.0 to 6.5, indicating a weakly acidic nature. This is determined to be the result of precisely adjusting the pH by sequentially mixing hydrangea extract, a complex peeling active ingredient, a moisturizing ingredient, and an elasticity-enhancing ingredient, and finally adding a pH adjuster. The above pH range is a level suitable for minimizing skin irritation and protecting skin barrier function.

[0588] Comparative Example 1 showed a pH of 5.62, satisfying the weakly acidic range despite replacing the hydrangea extract with purified water. This appears to be due to the acidic characteristics of the peeling active ingredient and the appropriate use of a pH adjuster. However, due to the absence of hydrangea extract, it is judged that it is difficult to expect skin moisturization and elasticity improvement effects through hydrangenol.

[0589] Comparative Example 2 exhibited a pH of 3.78, which significantly deviated from the weakly acidic range of pH 5.0 to 6.5. This is judged to be due to the use of a single component, glycolic acid, at a high concentration instead of a complex peeling active ingredient, resulting in strong acidity. Glycolic acid is a strong acid with a pKa of 3.83; when used in a high concentration of 3.5 g, it makes the entire composition strongly acidic, which poses a high risk of causing skin irritation and damaging the skin barrier. Therefore, Comparative Example 2 is not suitable as a cosmetic for daily home care, and it can be confirmed that the low-concentration formulation of the complex peeling active ingredient presented in the present invention is essential for achieving low-irritation peeling.

[0590] Comparative Example 3 satisfied the weakly acidic range by exhibiting a pH of 5.54, even though the elasticity-enhancing ingredient mixture was replaced with purified water. This appears to be due to the pH characteristics of the remaining ingredients and the action of the pH regulator. However, due to the absence of peptides, adenosine, retinol derivatives, and plant collagen precursors, the skin elasticity-enhancing effect is expected to be significantly reduced.

[0591] Based on the above results, it was confirmed that Example 1 is an optimal composition capable of simultaneously achieving low-irritation peeling, moisturizing, and elasticity-enhancing effects by including hydrangea extract, a complex peeling active ingredient, a moisturizing ingredient, and an elasticity-enhancing ingredient, while satisfying a weakly acidic range of pH 5.0 to 6.5.

[0592] [Visual Stability Assessment]

[0593] 30 g of each cosmetic composition prepared in Example 1 and Comparative Examples 1 to 3 was placed in a transparent glass container and sealed. The container was stored under constant temperature and humidity conditions maintained at 25°C and 60% relative humidity. Visual changes in each composition were observed and recorded at 0, 1, 2, and 4 weeks. The observation items included vertical separation, precipitation, color change, bubble formation, and viscosity change. At each observation point, the container was tilted horizontally to check fluidity and to check for the presence of precipitation at the bottom of the container. Color change was observed against a white background and compared with the initial color.

[0594] division 0 weeks 1 week 2 weeks 4 weeks Comprehensive Stability Assessment Example 1 Uniform cream texture, white, no bubbles No change No change No change excellence Comparative Example 1 Uniform cream texture, white, no bubbles No change No change Slight moisture separation observed commonly Comparative Example 2 Uniform cream texture, white, no bubbles Surface microbubble generation Start separating top and bottom Clear two-layer separation, upper layer transparency error Comparative Example 3 Uniform cream texture, white, no bubbles No change Viscosity decreased slightly Continued decrease in viscosity, increased liquidity commonly

[0595] No instability phenomena, such as vertical separation, precipitation, color change, or bubble generation, were observed in the cosmetic composition of Example 1 throughout the entire period from week 0 to week 4. This is attributed to the fact that hydrangea extract, peeling active ingredients, moisturizing ingredients, and elasticity-enhancing ingredients were sequentially added dropwise, and stirred at an appropriate speed and time at each stage, resulting in the formation of a uniform dispersion among the ingredients and a stable emulsion structure. In particular, it is analyzed that the physical stability of the formulation was secured by effectively removing microbubbles introduced during the mixing process through vacuum degassing, and by finely reducing and homogenizing the particle size to 2.1 μm through multi-stage homogenization.

[0596] Comparative Example 1 maintained a relatively stable state until the 4th week despite the exclusion of hydrangea extract, but slight water separation was observed at the 4th week. This suggests that hydrangea extract contributes to the stabilization of the formulation to some extent, and that in its absence, slight instability may occur during long-term storage. It is presumed that the polyphenol compounds and sugar components contained in the hydrangea extract interact with moisturizing ingredients and elasticity-enhancing ingredients to improve the stability of the formulation.

[0597] Comparative Example 2 exhibited severe instability, with microbubbles beginning to form on the surface from the first week, upper and lower separation starting in the second week, and the upper layer becoming transparent along with clear two-layer separation in the fourth week. This is attributed to the high concentration of glycolic acid as a single component, which destroyed the emulsion structure and excessively lowered the pH, thereby degrading the functions of the emulsifier and thickener. Since glycolic acid is strongly acidic, it is analyzed that under conditions of pH 3.78, the emulsifying power of nonionic emulsifiers such as cetearyl alcohol and glyceryl stearate decreased, and viscosity was not sufficiently formed because thickeners such as carbomer were not neutralized. Furthermore, it appears that the overall formulation stability collapsed due to accelerated degradation of hyaluronic acid and reduced stability of peptides under strongly acidic conditions. Therefore, it can be clearly confirmed that the low-concentration formulation method of the complex peeling active ingredient presented in the present invention is essential for ensuring formulation stability.

[0598] Comparative Example 3 excluded the elasticity-enhancing ingredient mixture, and a phenomenon was observed in which viscosity began to decrease slightly from the second week and fluidity increased by the fourth week. It is believed that ingredients such as peptides and plant extracts included in the elasticity-enhancing ingredients contribute to the viscosity and structural stability of the formulation. In particular, plant extracts such as Centella asiatica extract, red ginseng extract, and green tea extract contain polysaccharides and protein components, and are presumed to strengthen the network structure by interacting with moisturizing ingredients and thickeners.

[0599] Synthesizing the above results, it was confirmed that Example 1 can maintain a stable formulation for more than 4 weeks at 25°C through the optimal combination of hydrangea extract, a complex peeling active ingredient, a moisturizing ingredient, and an elasticity-enhancing ingredient, as well as sequential mixing and a multi-stage homogenization process. On the other hand, as shown in Comparative Example 2, serious formulation instability occurs when a high concentration single acid ingredient is used instead of the complex peeling active ingredient; thus, it was proven that the hypoallergenic complex peeling system of the present invention is an essential component for simultaneously achieving stability and efficacy.

Claims

Claim 1 A method for preparing a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling, comprising: (a) a step of preparing a hydrangea extract by extracting the leaves of *Hydrangea serrata* with hot water, wherein the hydrangea extract is prepared to contain 0.5 to 2.0 weight% of hydrangenol; (b) a peeling active ingredient, wherein the peeling active ingredient comprises an enzyme peeling agent comprising an AHA (Alpha Hydroxy Acid) containing one or more selected from the group consisting of glycolic acid, lactic acid, mandelic acid, and citric acid; a BHA (Beta Hydroxy Acid) containing salicylic acid or a derivative thereof; a PHA (Poly Hydroxy Acid) containing gluconolactone or lactobionic acid; and one or more selected from the group consisting of papain, bromelain, pumpkin enzyme, and pineapple enzyme. Ingredient preparation step; (c) a moisturizing ingredient preparation step comprising a moisturizing ingredient comprising one or more natural moisturizing factors selected from the group consisting of hyaluronic acid, glycerin, butylene glycol, dipropylene glycol, sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline; (d) an elasticity-enhancing ingredient preparation step comprising a peptide comprising one or more selected from the group consisting of palmitoyl pentapeptide-4, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, acetyl hexapeptide-8, copper tripeptide-1, and carnosine, adenosine, a retinol derivative comprising one or more selected from the group consisting of retinol, retinyl palmitate, retinyl acetate, retinaldehydride, and retinoic acid, and Centella asiatica extract, red ginseng extract, green tea extract, A step of preparing an elasticity-enhancing ingredient comprising a plant-based collagen precursor including one or more selected from the group consisting of aloe vera extract and licorice extract; (e) 5 to 30 parts by weight of the hydrangea extract from step (a),A mixing step of preparing a mixture by mixing 1 to 15 parts by weight of the peeling active ingredient of step (b), 10 to 40 parts by weight of the moisturizing ingredient of step (c), and 1 to 20 parts by weight of the elasticity-enhancing ingredient of step (d); (f) preparing a weakly acidic cosmetic composition with a pH in the range of 5.0-6.5 by further infusing the mixture of step (e) an emulsifier comprising one or more selected from the group consisting of cetearyl alcohol, glyceryl stearate, PEG-100 stearate, sorbitan oleate, and caprylyl / capryl glucoside, a thickener comprising one or more selected from the group consisting of carbomer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer, and polyisobutene, a preservative comprising one or more selected from the group consisting of 1,2-hexanediol and phenoxyethanol, and a pH adjuster comprising triethanolamine. Formulation step; and (g) a homogenization step of homogenizing the cosmetic composition of step (f) above to obtain a final cosmetic composition; wherein step (a) is a step of preparing a raw material by washing and hot-air drying hydrangea leaves, adding purified water, obtaining an extract by hot-water extraction at 95°C to 100°C, obtaining a filtrate by filtering with a membrane filter, preparing a concentrate using a vacuum concentrator, obtaining hydrangea extract powder through freeze-drying or spray-drying, and preparing a hydrangea extract containing a certain amount of hydrangenol by analyzing and confirming the hydrangenol content in the hydrangea extract powder using HPLC or LC-MS / MS with a calibration curve method; and step (b) is a step of preparing an AHA including glycolic acid, lactic acid, mandelic acid, and citric acid with a solvent, preparing a BHA including salicylic acid or a derivative with a solvent, and including gluconolactone or lactobionic acid Prepare PHA with a solvent, and prepare an enzyme peeling agent containing papain, bromelain, pumpkin enzyme, and pineapple enzyme with a solvent, and then,The step of preparing a low-irritation peeling active ingredient mixture by mixing the prepared peeling active ingredients and adjusting with a solvent, and the step (c) is to prepare low molecular weight hyaluronic acid with a molecular weight of less than 10 kDa, medium molecular weight hyaluronic acid with a molecular weight of 10 kDa or more and 100 kDa or less, and high molecular weight hyaluronic acid with a molecular weight of more than 100 kDa, each with a solvent, prepare glycerin with a solvent, prepare butylene glycol with a solvent, prepare dipropylene glycol with a solvent, and prepare sodium pyrrolidone carboxylate, serine, glycine, alanine, arginine, and proline, each as natural moisturizing factors with a solvent, and then mix the prepared moisturizing ingredients and adjust with a solvent, and the step (d) is to prepare palmitoyl pentapeptide-4, palmitoyl tripeptide-1, palmitoyl tetrapeptide-7, acetyl hexapeptide-8, copper tripeptide-1 and The step of preparing carnosine as a peptide with a solvent, preparing adenosine with a solvent, preparing retinol, retinyl palmitate, retinyl acetate, retinaldehydride, and retinoic acid as retinol derivatives with a solvent, and preparing Centella asiatica extract, red ginseng extract, green tea extract, aloe vera extract, and licorice extract as plant collagen precursors with a solvent, and then mixing the prepared elasticity-enhancing ingredients and adjusting with a solvent to prepare a mixture of elasticity-enhancing ingredients; and the above step (e) involves preparing a mixing container and maintaining it at 20°C to 30°C, first adding moisturizing ingredients and performing a first stirring, slowly adding hydrangea extract by dropwise stirring while performing a second stirring, slowly adding peeling active ingredients by dropwise stirring while performing a third stirring, slowly adding elasticity-enhancing ingredients by dropwise stirring while performing a fourth stirring, and then performing a degassing treatment under reduced pressure conditions using a vacuum degassing machine to prepare a mixture in which each ingredient is uniformly mixed. Step (f) comprises preparing an emulsifier comprising cetearyl alcohol, glyceryl stearate, PEG-100 stearate, sorbitan oleate, and caprylyl / capryl glucoside, andA step of preparing a cosmetic composition by preparing a thickener comprising carbomer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer, and polyisobutene; preparing a preservative comprising 1,2-hexanediol and phenoxyethanol; and preparing a pH adjuster comprising triethanolamine, then sequentially adding an emulsifier, a thickener, and a preservative to the mixture, stirring each, measuring the pH, adjusting it to a weakly acidic range using a pH adjuster, and finally stirring while cooling; and the above step (g) comprises introducing the cosmetic composition into a homogenizing device and performing primary homogenization using a homomixer while maintaining a temperature of 25°C to 35°C, performing secondary homogenization using a high-shear homogenizer rotating at a speed of 8,000 rpm to 12,000 rpm, performing tertiary homogenization by repeatedly passing the composition through a high-pressure homogenizer having a pressure of 80 bar to 150 bar, and then a laser A method for manufacturing a cosmetic composition having moisturizing and elasticity-enhancing effects through low-irritation peeling, characterized by the step of measuring the average particle size by diffraction and adjusting the particle size by additional homogenization if necessary, measuring the viscosity by Brookfield rotational viscometer and adjusting the viscosity by adding a thickener if necessary, and then filling into a container to obtain a final cosmetic composition. Claim 2 delete Claim 3 delete

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