Preparation method of external skin care product

Abstract

The invention discloses a preparation method of an external skin care product, belongs to the technical field of cosmetics, and aims to solve the problems of weak effect of a single target spot, poor transdermal permeability of active ingredients and easy inactivation in the prior art. The method comprises the following steps: preparing a composition containing an A-phase licorice extract and a B-phase bearberry extract, wherein the mass ratio of the A phase to the B phase is 1: (1.5-3); the preparation method comprises the following steps: preparing a liposome suspension of which the entrapment rate is greater than or equal to 88% and the particle size is 50-200nm by using a hydrogenated soybean lecithin-phytosterol-ceramide composite membrane material through a membrane dispersion-high-pressure homogenization method; mixing with auxiliary materials to prepare essence or emulsion; and smearing according to 0.5-1mg / cm < 2 > to realize double-target synergistic blackening inhibition. According to the scheme, the melanin inhibition rate reaches 54%-62% through the double-target design in cooperation with composite membrane material liposome delivery, the active ingredient retention rate is larger than or equal to 89% after storage at 45 DEG C for 6 months, the transdermal rate is increased to 40%-48%, and the method is mild, low in irritation and remarkable in application value.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, specifically to a method for preparing a topical skincare product. Background Technology

[0002] Excessive melanin production is the main cause of dull skin and age spots. Its synthesis process is regulated by multiple links: the key transcription factor MITF regulates the expression of key enzymes in melanin synthesis such as tyrosinase and tyrosinase-associated protein 1. Tyrosinase is the rate-limiting enzyme in the melanin synthesis pathway, which directly catalyzes the conversion of tyrosine to dopaquinone.

[0003] Existing skin whitening technologies mostly focus on single-target inhibition, such as using bearberry extract to inhibit tyrosinase or using vitamin C derivatives to block melanin synthesis. However, these technologies have problems such as limited effectiveness, poor transdermal absorption of active ingredients, and easy oxidation and inactivation.

[0004] Although some studies have mentioned the whitening applications of licorice extract and bearberry extract, they have not clarified the synergistic effect of the two on the dual targets of "MITF transcription factor + tyrosinase", and lack the encapsulation design of specific composite membrane liposomes. Existing conventional liposomes mostly use a single lecithin membrane material, which has insufficient stability and transdermal permeability, making it difficult to achieve efficient delivery of active ingredients.

[0005] Therefore, a whitening method based on clearly defined dual targets and encapsulation with liposomes using specific composite membrane materials is proposed to improve whitening effect and product stability. Summary of the Invention

[0006] To address the shortcomings of existing technologies, such as weak single-target inhibition, low delivery efficiency of active ingredients, and poor stability, this invention provides a whitening method that synergistically inhibits melanin production through dual targets. By combining a specific ratio of biphasic active ingredients with composite membrane liposomes, both transdermal permeability and stability are enhanced.

[0007] To achieve the above objectives, the present invention provides the following technical solution: The technical solution provided by this invention is: A method for preparing a topical skincare product includes the following steps: S1: Prepare an active ingredient composition, which includes phase A and phase B; phase A is licorice extract which inhibits the key transcription factor MITF in melanin production, and phase B is bearberry extract which inhibits tyrosinase activity. The mass ratio of phase A to phase B is 1:(1.5-3). S2: The active ingredient composition is encapsulated by a composite membrane material mixed with liposomes to obtain a liposome suspension with an encapsulation rate of ≥88% and a liposome particle size of 50-200nm; S3: Mix liposome suspension with cosmetic excipients to prepare a topical whitening preparation; S4: Apply the topical whitening preparation to the skin surface. Through the transdermal penetration of liposomes, the A and B phase components enter the basal layer of the skin, respectively inhibiting the expression of MITF and the activity of tyrosinase, and synergistically blocking melanin production.

[0008] Furthermore, the mass content of glycyrrhizin A in phase A licorice extract is ≥45%; and the mass content of arbutin in phase B bearberry extract is ≥90%.

[0009] Furthermore, the composite membrane material in S2 is composed of hydrogenated soybean lecithin, phytosterols, and ceramides in a mass ratio of (5-7):1:(0.5-1); liposomes are prepared using a thin-film dispersion-high pressure homogenization method. The specific steps are as follows: S1: Dissolve the composite membrane material and tocopheryl succinate in anhydrous ethanol and stir at 60-70℃ until completely dissolved to form a membrane material solution; S2: Dissolve the active ingredient composition in a phosphate buffer solution with a pH of 5.5-6.0 to obtain an aqueous solution; S3: Add the membrane material solution to a rotary evaporator and rotary evaporate at 50-60℃ and a vacuum of 0.08-0.1MPa for 1-2 hours to remove ethanol and form a uniform lipid membrane on the inner wall of the flask. S4: Add the aqueous solution to the flask and stir at 60-70℃ for 30-40 minutes to form the initial emulsion; S5: Place the colostrum in a high-pressure homogenizer and homogenize it 3-5 times at a pressure of 800-1200 bar to obtain a liposome suspension.

[0010] Furthermore, in topical whitening preparations, the mass percentage of liposome suspension is 10-30%; cosmetic excipients include glycerin, sodium hyaluronate, xanthan gum and deionized water, of which glycerin accounts for 5-10% by mass, sodium hyaluronate for 0.1-0.5%, and xanthan gum for 0.1-0.3%.

[0011] Furthermore, topical whitening preparations are available in the form of serums or lotions.

[0012] Furthermore, the application rate of the topical whitening agent in S4 is 0.5-1 mg / cm³. 2 Apply once or twice daily for ≥28 days.

[0013] Furthermore, the licorice extract was prepared by the following method: dried licorice root was taken, pulverized, and extracted twice by reflux with 60-70% ethanol for 2-3 hours each time. The extracts were combined, concentrated under reduced pressure until no alcohol odor was detected, purified by D101 macroporous resin, and the 60% ethanol eluent was collected and spray-dried to obtain the licorice extract.

[0014] Furthermore, the bearberry extract was prepared by the following method: dried bearberry leaves were taken, pulverized, and ultrasonically extracted with 50-60% ethanol for 60-90 minutes at an extraction temperature of 40-50℃. The extract was filtered through a 0.45μm filter membrane, concentrated under reduced pressure to a paste, and vacuum dried to obtain the bearberry extract.

[0015] Furthermore, the composite membrane material also contains tocopherol succinate at a mass ratio of 5-8% of the total mass of the membrane material.

[0016] The beneficial effects of this technical solution are: (1) The licorice extract in phase A contains glycyrrhizin A, which can specifically act on the regulatory link of melanin production. By inhibiting the expression of the key transcription factor MITF, it reduces the production of melanin synthesis-related enzymes from the source. The high-purity arbutin in the bearberry extract in phase B can directly act on tyrosinase, the rate-limiting enzyme of melanin synthesis, and block the conversion of tyrosine to dopaquinone. The two are combined in a specific ratio to form a dual-target inhibition system, avoiding the limitation of a single component acting on a single pathway, and achieving synergistic control of the entire chain of melanin production.

[0017] (2) Hydrogenated soybean lecithin, as a base membrane material, has good biocompatibility and encapsulation capacity, and can effectively encapsulate fat-soluble and water-soluble active ingredients. The addition of phytosterols can regulate the fluidity of the membrane material and enhance the stability of the liposome structure. Ceramides are homologous to skin barrier components, which can enhance the affinity between liposomes and skin and help them penetrate the stratum corneum. The tocopheryl succinate has both antioxidant properties and membrane stability, which can prevent the active ingredients from being oxidized and degraded, and strengthen the liposome membrane structure, thus solving the problem of natural active ingredients being easily inactivated and having poor transdermal permeability.

[0018] (3) Glycerin and sodium hyaluronate form a dual moisturizing system, which can alleviate the skin dryness problem that may be caused by active ingredients, and at the same time improve the skin feel of the formulation; Xanthan gum, as a thickener, can maintain the stable form of serum and lotion, and avoid layering or sedimentation. All ingredients are made from cosmetic grade raw materials. Licorice extract and bearberry extract are both natural plant sources. Combined with conventional mild excipients, the risk of skin irritation is reduced, making it suitable for different skin types and taking into account both efficacy and safety. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating the preparation method of a topical skincare product proposed in this invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The specific implementation process is as follows: Example 1: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, which adopts an essence dosage form, wherein A:B=1:2 and the film material ratio is 6:1:0.8; S1: Extract Preparation S1-1: Licorice Extract: Take 500g of dried licorice root, grind it to 20 mesh, add 1500mL of 65% ethanol, place it in a reflux extraction device, heat to boiling, and maintain reflux extraction twice, 2.5h each time. Combine the two extracts, filter with a Buchner funnel to remove residue, place the filtrate in a rotary evaporator, and concentrate under reduced pressure at 55℃ and 0.09MPa until no alcohol odor is detected to obtain an extract; dilute the extract with deionized water to 100mL, load it onto a pretreated D101 macroporous resin column, first wash with deionized water until the eluent is colorless, then elute with 60% ethanol, collect the eluent, and spray dry (inlet air temperature 180℃, outlet air temperature 80℃) to obtain 120g of licorice extract; the content of glycyrrhizin A in this licorice extract is 48%, and the remainder is glycyrrhizic acid 30%, flavonoid derivatives 15%, and plant polysaccharides 7%; S1-2: Bearberry Extract: Take 500g of dried bearberry leaves, pulverize to 20 mesh, add 1500mL of 55% ethanol, place in an ultrasonic extractor, set the temperature to 45℃ and power to 300W, and ultrasonically extract for 75min. After extraction, filter through a 0.45μm organic filter membrane. Place the filtrate in a rotary evaporator and concentrate under reduced pressure at 50℃ and 0.08MPa to a paste (relative density 1.20, 25℃). Place the paste in a vacuum drying oven and dry at 60℃ and -0.09MPa for 8h to obtain 100g of bearberry extract. The bearberry extract contains 92% arbutin, with the remainder being 5% arbutin derivatives, 2% tannins, and 1% plant fiber residue. S2: Preparation of Active Ingredient Composition Accurately weigh 10.0g of licorice extract (phase A, glycyrrhizin A content 48%) and 20.0g of arbutin extract (phase B, arbutin content 92%) using an electronic balance, place them in a stainless steel mixing jar, and stir at 300r / min for 15min until they are evenly mixed to obtain 30.0g of active ingredient composition. S3: Liposome Preparation S3-1: Preparation of membrane material solution: Weigh 30.0g of hydrogenated soybean lecithin (purity ≥98%), 5.0g of phytosterol (purity ≥95%), 4.0g of ceramide (purity ≥90%), and 2.34g of tocopherol succinate (6% of the total mass of the membrane material 39.0g), place them in a three-necked flask, add 200.0mL of anhydrous ethanol (analytical grade), place the three-necked flask in a constant temperature water bath, set the temperature to 65℃, and stir with an electric stirrer at a speed of 400r / min for 30min until the solids are completely dissolved to form a clear and transparent membrane material solution; S3-2: Preparation of aqueous solution: Take 300.0 mL of pH 5.8 phosphate buffer (0.05 mol / L, phosphate is analytical grade), add 30.0 g of active ingredient composition, stir with a magnetic stirrer at 500 r / min for 20 min until the composition is completely dissolved to obtain an aqueous solution; S3-3: Film formation process: The film material solution is transferred to the round bottom flask of the rotary evaporator, the temperature is set to 55℃ and the vacuum degree is 0.09MPa, and the evaporation is carried out at a speed of 60r / min for 1.5h. After the ethanol is completely removed, a uniform and smooth lipid film is formed on the inner wall of the flask. S3-4: Preparation of colostrum: Add aqueous solution to a round-bottom flask containing lipid membrane, place the flask in a constant temperature water bath, set the temperature to 65℃, and stir with an electric stirrer at a speed of 500r / min for 35min to allow the lipid membrane to swell completely and mix with the aqueous phase to form a milky white colostrum. S3-5: Homogenization: The colostrum was transferred to a high-pressure homogenizer, the pressure was set to 800 bar, and homogenized 4 times with a 2-minute interval between each homogenization to obtain 320.0 g of liposome suspension. The suspension was tested and found to have a loading rate of 91% and a liposome particle size of 120 nm. S4: Serum Preparation Weigh 200.0g of liposome suspension, 50.0g of glycerol, 2.0g of sodium hyaluronate, 1.0g of xanthan gum, and 747.0g of deionized water using an electronic balance. Add these ingredients sequentially to a stainless steel mixing jar. Place the mixing jar in a constant temperature water bath at 50℃ and stir at 600 rpm for 30 minutes until all materials are completely mixed and a clear, transparent liquid is formed. Stop stirring and allow the mixture to cool naturally to room temperature. Adjust the pH to 6.0 using a 0.1mol / L sodium hydroxide solution to obtain 1000.0g of the essence. The viscosity of the essence at 25℃ was measured to be 1500 mPa·s.

[0022] detection indicators Test results Liposome loading rate 91% Liposome particle size (nm) 120 Tyrosinase inhibition rate 68% MITF expression inhibition rate 62% Melanin content inhibition rate 58% Retention rate of active ingredients (glycyrrhizin chalcone A / arbutin) after 6 months of storage at 45℃ 92% / 93% Transdermal absorption rate 42% Skin irritation rating (0-5 points) 0.3 points In this embodiment, the liposome loading rate reached 91%, and the particle size of 120nm was within the optimal transdermal range of 50-200nm, laying the foundation for the delivery of active ingredients. The results of 68% tyrosinase inhibition rate and 62% MITF expression inhibition rate confirmed the effects of phase B arbutin extract (arbutin content 92%) and phase A licorice extract (licorice chalcone A content 48%) in the midstream blocking and upstream regulation links, respectively. The two worked synergistically to achieve a melanin content inhibition rate of 58%. After storage at 45℃ for 6 months, the retention rates of both glycyrrhizin A and arbutin exceeded 90%, demonstrating the excellent stability brought by the synergy of composite membrane material and tocopheryl succinate. The transdermal absorption rate of 42% highlighted the homology advantage of ceramides and the skin barrier. The skin irritation score was only 0.3 points, indicating that the ingredient combination is mild and safe, meeting the requirements for cosmetic use.

[0023] Example 2: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, which adopts an essence dosage form, wherein A:B=1:1.5 and the film material ratio is 7:1:1; S1: Extract Preparation S1-1: Licorice Extract: Take 500g of dried licorice root, grind it to 20 mesh, add 1500mL of 65% ethanol, place it in a reflux extraction device, heat to boiling, and maintain reflux extraction twice, 2.5h each time. Combine the two extracts, filter with a Buchner funnel to remove residue, place the filtrate in a rotary evaporator, and concentrate under reduced pressure at 55℃ and 0.09MPa until no alcohol odor is detected to obtain an extract; dilute the extract with deionized water to 100mL, load it onto a pretreated D101 macroporous resin column, first wash with deionized water until the eluent is colorless, then elute with 60% ethanol, collect the eluent, and spray dry (inlet air temperature 180℃, outlet air temperature 80℃) to obtain 120g of licorice extract; the content of glycyrrhizin A in this licorice extract is 48%, and the remainder is glycyrrhizic acid 30%, flavonoid derivatives 15%, and plant polysaccharides 7%; S1-2: Bearberry Extract: Take 500g of dried bearberry leaves, pulverize to 20 mesh, add 1500mL of 55% ethanol, place in an ultrasonic extractor, set the temperature to 45℃ and power to 300W, and ultrasonically extract for 75min. After extraction, filter through a 0.45μm organic filter membrane. Place the filtrate in a rotary evaporator and concentrate under reduced pressure at 50℃ and 0.08MPa to a paste (relative density 1.20, 25℃). Place the paste in a vacuum drying oven and dry at 60℃ and -0.09MPa for 8h to obtain 100g of bearberry extract. The bearberry extract contains 92% arbutin, with the remainder being 5% arbutin derivatives, 2% tannins, and 1% plant fiber residue. S2: Preparation of Active Ingredient Composition Accurately weigh 10.0g of licorice extract (phase A, glycyrrhizin A content 48%) and 15.0g of arbutin extract (phase B, arbutin content 92%), place them in a stainless steel mixing jar, stir at 300r / min for 15min, mix evenly, and obtain 25.0g of active ingredient composition. S3: Liposome Preparation S3-1: Preparation of membrane material solution: Weigh 35.0g of hydrogenated soybean lecithin (purity ≥98%), 5.0g of phytosterol (purity ≥95%), 5.0g of ceramide (purity ≥90%), and 2.25g of tocopherol succinate (5% of the total mass of the membrane material 45.0g), add 200.0mL of anhydrous ethanol (analytical grade), stir at 65℃ for 30min until dissolved, and obtain the membrane material solution; S3-2: Preparation of aqueous solution: Dissolve 25.0 g of the active ingredient composition in 300.0 mL of pH 6.0 phosphate buffer (0.05 mol / L, phosphate is analytical grade), stir for 20 min until dissolved, to obtain an aqueous solution. S3-3: Film formation process: The membrane material solution is rotary evaporated at 60℃ and 0.1MPa for 1 hour to form a lipid membrane; S3-4: Preparation of colostrum: Add aqueous solution and stir at 70℃ for 30 min to obtain colostrum; S3-5: Homogenization: Homogenize 3 times at 1000 bar pressure to obtain 315.0 g of liposome suspension. The loading rate was 89% and the particle size was 150 nm. S4: Serum Preparation Weigh 250.0g of liposome suspension, 70.0g of glycerol, 3.0g of sodium hyaluronate (molecular weight 1 million Da), 1.5g of xanthan gum, and 675.5g of deionized water. Stir at 50℃ for 30 minutes until homogeneous. After cooling, adjust the pH to 5.8 to obtain 1000.0g of essence. The viscosity at 25℃ is 1800mPa·s.

[0024] detection indicators Test results Liposome loading rate 89% Liposome particle size (nm) 150 Tyrosinase inhibition rate 62% MITF expression inhibition rate 65% Melanin content inhibition rate 55% Retention rate of active ingredients (glycyrrhizin chalcone A / arbutin) after 6 months of storage at 45℃ 90% / 91% Transdermal absorption rate 45% Skin irritation rating (0-5 points) 0.2 points This embodiment uses a lower limit ratio of phase A: phase B = 1:1.5. Reducing the amount of phase B (92% arbutin content) lowers the tyrosinase inhibition rate to 62%, but the proportion of phase A (48% glycyrrhizin chalcone A content) is relatively increased, raising the MITF expression inhibition rate to 65%, while still achieving a 55% melanin content inhibition rate, demonstrating the flexibility of dual-target synergy. The proportion of ceramide in the membrane material is increased to 1 part, enhancing the affinity between liposomes and skin, resulting in a transdermal absorption rate of 45%, higher than in Example 1. The liposome loading rate is 89%, and the particle size of 150nm can still effectively penetrate the stratum corneum. After storage at 45℃ for 6 months, the retention rate of active ingredients exceeds 90%, indicating good stability. The skin irritation score is 0.2, indicating that the mildness of the ingredient combination is not affected by minor adjustments to the ratio.

[0025] Example 3: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, which adopts an essence dosage form, wherein A:B=1:3 and the film material ratio is 5:1:0.5; S1: Extract Preparation S1-1: Licorice Extract: Take 500g of dried licorice root, grind it to 20 mesh, add 1500mL of 65% ethanol, place it in a reflux extraction device, heat to boiling, and maintain reflux extraction twice, 2.5h each time. Combine the two extracts, filter with a Buchner funnel to remove residue, place the filtrate in a rotary evaporator, and concentrate under reduced pressure at 55℃ and 0.09MPa until no alcohol odor is detected to obtain an extract; dilute the extract with deionized water to 100mL, load it onto a pretreated D101 macroporous resin column, first wash with deionized water until the eluent is colorless, then elute with 60% ethanol, collect the eluent, and spray dry (inlet air temperature 180℃, outlet air temperature 80℃) to obtain 120g of licorice extract; the content of glycyrrhizin A in this licorice extract is 48%, and the remainder is glycyrrhizic acid 30%, flavonoid derivatives 15%, and plant polysaccharides 7%; S1-2: Bearberry Extract: Take 500g of dried bearberry leaves, pulverize to 20 mesh, add 1500mL of 55% ethanol, place in an ultrasonic extractor, set the temperature to 45℃ and power to 300W, and ultrasonically extract for 75min. After extraction, filter through a 0.45μm organic filter membrane. Place the filtrate in a rotary evaporator and concentrate under reduced pressure at 50℃ and 0.08MPa to a paste (relative density 1.20, 25℃). Place the paste in a vacuum drying oven and dry at 60℃ and -0.09MPa for 8h to obtain 100g of bearberry extract. The bearberry extract contains 92% arbutin, with the remainder being 5% arbutin derivatives, 2% tannins, and 1% plant fiber residue. S2: Preparation of Active Ingredient Composition Accurately weigh 10.0g of licorice extract (phase A, glycyrrhizin A content 48%) and 30.0g of bearberry extract (phase B, arbutin content 92%), place them in a stainless steel mixing jar, stir at 300r / min for 15min, mix evenly, and obtain 40.0g of active ingredient composition. S3: Liposome Preparation S3-1: Preparation of membrane material solution: Weigh 25.0g of hydrogenated soybean lecithin (purity ≥98%), 5.0g of phytosterol (purity ≥95%), 2.5g of ceramide (purity ≥90%), and 3.4g of tocopherol succinate (8% of the total mass of the membrane material 32.5g), add 200.0mL of anhydrous ethanol (analytical grade), stir at 60℃ for 30min until dissolved, and obtain the membrane material solution; S3-2: Preparation of aqueous solution: Dissolve 40.0g of the active ingredient composition in 300.0mL of pH 5.5 phosphate buffer (0.05mol / L, phosphate is analytical grade), stir for 20min until dissolved, to obtain an aqueous solution; S3-3: Film formation process: The membrane material solution is rotary evaporated at 50℃ and 0.08MPa for 2 hours to form a lipid membrane; S3-4: Preparation of colostrum: Add aqueous solution and stir at 60℃ for 40 min to obtain colostrum; S3-5: Homogenization: Homogenize 5 times at 1200 bar to obtain 330.0 g of liposome suspension. The loading rate was 92% and the particle size was 80 nm. S4: Serum Preparation Weigh out 150.0g of liposome suspension, 100.0g of glycerol, 5.0g of sodium hyaluronate (molecular weight 1 million Da), 3.0g of xanthan gum, and 742.0g of deionized water. Stir at 50℃ for 30 minutes until homogeneous. After cooling, adjust the pH to 6.5 to obtain 1000.0g of essence. The viscosity at 25℃ is 1200mPa·s.

[0026] detection indicators Test results Liposome loading rate 92% Liposome particle size (nm) 80 Tyrosinase inhibition rate 75% MITF expression inhibition rate 58% Melanin content inhibition rate 62% Retention rate of active ingredients (glycyrrhizin chalcone A / arbutin) after 6 months of storage at 45℃ 93% / 94% Transdermal absorption rate 48% Skin irritation rating (0-5 points) 0.4 points In this embodiment, the upper limit ratio of phase A: phase B = 1:3 was used. The amount of arbutin extract (92% arbutin content) in phase B was increased, which increased the tyrosinase inhibition rate to 75%. Although the MITF expression inhibition rate of licorice extract (48% glycyrrhizin A content) in phase A decreased to 58%, the melanin content inhibition rate reached 62% under synergistic effect, which was the highest in the embodiment. High-pressure homogenization at 1200 bar for 5 times reduced the liposome particle size to 80nm. Combined with the optimization of membrane material ratio, the loading rate was increased to 92%, and the transdermal absorption rate reached 48%, which further enhanced the delivery efficiency of active ingredients. The amount of 8% tocopherol succinate resulted in an active ingredient retention rate of over 93% after storage at 45°C for 6 months, with optimal stability. The skin irritation score was 0.4, which is still at a low irritation level, proving that the high proportion of arbutin did not significantly increase irritation.

[0027] Example 4: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, which adopts an emulsion formulation, wherein A:B=1:2 and the film material ratio is 6:1:0.8; S1: Extract Preparation S1-1: Licorice Extract: Take 500g of dried licorice root, grind it to 20 mesh, add 1500mL of 65% ethanol, place it in a reflux extraction device, heat to boiling, and maintain reflux extraction twice, 2.5h each time. Combine the two extracts, filter with a Buchner funnel to remove residue, place the filtrate in a rotary evaporator, and concentrate under reduced pressure at 55℃ and 0.09MPa until no alcohol odor is detected to obtain an extract; dilute the extract with deionized water to 100mL, load it onto a pretreated D101 macroporous resin column, first wash with deionized water until the eluent is colorless, then elute with 60% ethanol, collect the eluent, and spray dry (inlet air temperature 180℃, outlet air temperature 80℃) to obtain 120g of licorice extract; the content of glycyrrhizin A in this licorice extract is 48%, and the remainder is glycyrrhizic acid 30%, flavonoid derivatives 15%, and plant polysaccharides 7%; S1-2: Bearberry Extract: Take 500g of dried bearberry leaves, pulverize to 20 mesh, add 1500mL of 55% ethanol, place in an ultrasonic extractor, set the temperature to 45℃ and power to 300W, and ultrasonically extract for 75min. After extraction, filter through a 0.45μm organic filter membrane. Place the filtrate in a rotary evaporator and concentrate under reduced pressure at 50℃ and 0.08MPa to a paste (relative density 1.20, 25℃). Place the paste in a vacuum drying oven and dry at 60℃ and -0.09MPa for 8h to obtain 100g of bearberry extract. The bearberry extract contains 92% arbutin, with the remainder being 5% arbutin derivatives, 2% tannins, and 1% plant fiber residue. S2: Preparation of Active Ingredient Composition Accurately weigh 10.0g of licorice extract (phase A, glycyrrhizin A content 48%) and 20.0g of arbutin extract (phase B, arbutin content 92%) using an electronic balance, place them in a stainless steel mixing jar, and stir at 300r / min for 15min until they are evenly mixed to obtain 30.0g of active ingredient composition. S3: Liposome Preparation S3-1: Preparation of membrane material solution: Weigh 30.0g of hydrogenated soybean lecithin (purity ≥98%), 5.0g of phytosterol (purity ≥95%), 4.0g of ceramide (purity ≥90%), and 2.34g of tocopherol succinate (6% of the total mass of the membrane material 39.0g), place them in a three-necked flask, add 200.0mL of anhydrous ethanol (analytical grade), place the three-necked flask in a constant temperature water bath, set the temperature to 65℃, and stir with an electric stirrer at a speed of 400r / min for 30min until the solids are completely dissolved to form a clear and transparent membrane material solution; S3-2: Preparation of aqueous solution: Take 300.0 mL of pH 5.8 phosphate buffer (0.05 mol / L, phosphate is analytical grade), add 30.0 g of active ingredient composition, stir with a magnetic stirrer at 500 r / min for 20 min until the composition is completely dissolved to obtain an aqueous solution; S3-3: Film formation process: The film material solution is transferred to the round bottom flask of the rotary evaporator, the temperature is set to 55℃ and the vacuum degree is 0.09MPa, and the evaporation is carried out at a speed of 60r / min for 1.5h. After the ethanol is completely removed, a uniform and smooth lipid film is formed on the inner wall of the flask. S3-4: Preparation of colostrum: Add aqueous solution to a round-bottom flask containing lipid membrane, place the flask in a constant temperature water bath, set the temperature to 65℃, and stir with an electric stirrer at a speed of 500r / min for 35min to allow the lipid membrane to swell completely and mix with the aqueous phase to form a milky white colostrum. S3-5: Homogenization: The colostrum was transferred to a high-pressure homogenizer, the pressure was set to 800 bar, and homogenized 4 times with a 2-minute interval between each homogenization to obtain 320.0 g of liposome suspension. The loading rate was 91% and the particle size was 120 nm. S4: Emulsion Preparation S4-1: Aqueous phase preparation: Weigh 100.0g of liposome suspension, 80.0g of glycerol, 4.0g of sodium hyaluronate (molecular weight 1 million Da), 2.0g of xanthan gum, and 654.0g of deionized water, place them in a stainless steel mixing jar, and stir at 50℃ for 20min until completely dissolved to obtain the aqueous phase; S4-2: Oil phase preparation: Weigh 15.0g of polyglycerol-3 diisostearate (emulsifier) ​​and 135.0g of squalane, place them in another stainless steel mixing jar, heat and stir at 70℃ for 10min until completely melted and mixed evenly to obtain the oil phase; S4-3: Emulsification process: Slowly add the oil phase to the water phase (stirring speed 800 r / min) while stirring. After the addition is complete, continue stirring for 10 min. Then transfer the mixture to a homogenizer and homogenize at 70℃ for 5 min (speed 10000 r / min) to form a uniform emulsion. S4-5: Cooling and Adjustment: The emulsion was naturally cooled to room temperature, and the pH was adjusted to 6.2 with 0.1 mol / L hydrochloric acid solution to obtain 1000.0 g of emulsion. The viscosity at 25℃ was measured to be 2500 mPa·s.

[0028] detection indicators Test results Liposome loading rate 91% Liposome particle size (nm) 125nm Tyrosinase inhibition rate 67% MITF expression inhibition rate 61% Melanin content inhibition rate 57% Retention rate of active ingredients (glycyrrhizin chalcone A / arbutin) after 6 months of storage at 45℃ 92% / 93% Transdermal absorption rate 40% Skin irritation rating (0-5 points) 0.2 points Emulsion stability (6 months at 45°C) No stratification, no oil separation In this embodiment, although the proportion of liposome suspension was reduced to 10%, the tyrosinase inhibition rate of phase B arbutin extract (92% arbutin content) was 67%, and the MITF expression inhibition rate of phase A licorice extract (48% glycyrrhizin chalcone A content) was 61%, still achieving a 57% melanin content inhibition rate. The efficacy was not affected by the formulation. The addition of oil phase components squalane and polyglycerol-3 diisostearate slightly reduced the transdermal absorption rate to 40%, but improved the product's moisturizing properties and skin feel. The emulsion showed no separation or oil separation after 6 months of storage at 45°C, with an active ingredient retention rate of over 92%, demonstrating good physical and chemical stability. The skin irritation score was 0.2, indicating that the emulsion formulation is more suitable for dry skin and has excellent gentleness.

[0029] Example 5: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an essence, wherein A:B=1:2, the film material ratio is 5:1:0.5, and tocopherol is 6%; The preparation is the same as in Example 1, except that: Active ingredient composition: 10.0g of licorice extract (containing 48% glycyrrhizin chalcone A, balance 30% glycyrrhizic acid, 15% flavonoids, and 7% polysaccharides) and 20.0g of bearberry extract (containing 92% arbutin, balance 5% phenols, 2% tannins, and 1% fiber) (A:B=1:2). Composite membrane material: 25.0g hydrogenated soybean lecithin, 5.0g phytosterol, 2.5g ceramide (5:1:0.5), 1.95g tocopherol succinate (6% of the total membrane material of 32.5g); Homogenization parameters: Homogenize 4 times at 1000 bar. Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 90% 100 66% 63% 57% 91% / 92% 46% In this embodiment, the composite membrane material ratio was adjusted to 5:1:0.5, and the homogenization pressure was increased to 1000 bar. Data showed that the liposome particle size decreased to 100 nm, and the transdermal permeability increased to 46%. This confirms that reducing the proportion of phytosterols and ceramides in the membrane material, combined with optimized homogenization pressure, can refine the particle size and enhance transdermal performance. The core ratio of active ingredients A:B is maintained at 1:2. The synergistic effect of 66% tyrosinase inhibition rate and 63% MITF inhibition rate results in a melanin inhibition rate of 57%. At the same time, 6% tocopherol succinate ensures a retention rate of over 91% at 45°C, achieving a balance between efficacy and stability.

[0030] Example 6: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an essence, wherein A:B=1:1.5, the film material ratio is 5:1:0.5, and tocopherol is 7%; The preparation is the same as in Example 1, except that: Active ingredient composition: licorice extract 10.0g, bearberry extract 15.0g (A:B=1:1.5); Composite membrane material: 25.0g hydrogenated soybean lecithin, 5.0g phytosterols, 2.5g ceramides, and 2.28g tocopherol succinate (7% of the total membrane material of 32.5g). Aqueous phase pH: 5.6; Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 89% 95 61% 66% 54% 92% / 93% 47% In this embodiment, the A:B ratio was reduced to 1:1.5. The reduced amount of bearberry extract in phase B led to a decrease in the tyrosinase inhibition rate to 61%, but the proportion of licorice extract in phase A was relatively increased, and the MITF inhibition rate rose to 66%. The dual-target synergy still achieved a melanin inhibition rate of 54%, demonstrating the flexibility of ratio adjustment. The membrane material ratio was consistent with that in Example 5, and the particle size of 95nm was the smallest in the example. Combined with an aqueous phase environment of pH 5.6, the transdermal permeability reached 47%. The 7% tocopherol succinate increased the retention rate of active ingredients to over 92%, further improving stability.

[0031] Example 7: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an essence, wherein A:B=1:3, the film material ratio is 7:1:1, and the tocopherol content is 5%; The preparation is the same as in Example 1, except that: Active ingredient composition: licorice extract 10.0g, bearberry extract 30.0g (A:B=1:3); Composite membrane material: 35.0g hydrogenated soybean lecithin, 5.0g phytosterols, 5.0g ceramides, 2.25g tocopherol succinate (5% of the total membrane material of 45g); Homogenization pressure: 1100 bar.

[0032] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 91% 160 74% 59% 61% 89% / 90% 44% In this embodiment, the A:B ratio reaches the upper limit of 1:3. The amount of bearberry extract in phase B is significantly increased, and the tyrosinase inhibition rate rises to 74%, which is the highest value of this indicator in the embodiment. This directly promotes the melanin inhibition rate to 61%. The membrane material ratio is 7:1:1. The increase in the proportion of ceramide increases the particle size to 160nm, but it is still within the optimal range for transdermal absorption, with a transdermal absorption rate of 44%. The amount of 5% tocopherol succinate is the lowest in the embodiment, corresponding to an active ingredient retention rate of 89%-90%, which is slightly lower than other embodiments, clearly demonstrating the positive correlation between tocopherol dosage and stability.

[0033] Example 8: Please see Figure 1The present invention provides a technical solution: a method for preparing a topical skin care product, using an emulsion, wherein A:B=1:1.5, the film material ratio is 6:1:0.8, and the tocopherol content is 6%; The preparation is the same as in Example 1, except that: Active ingredient composition: licorice extract 10.0g, bearberry extract 15.0g (A:B=1:1.5); Liposome preparation: Same membrane material ratio as in Example 1, with 2.34 g of tocopherol; Oil phase of emulsion: 10g polyglycerol-3 diisostearate, 120g squalane.

[0034] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Emulsion stability Transdermal rate 90% 130 63% 64% 55% No layering 43% This embodiment is an emulsion formulation with an A:B ratio of 1:1.5. Reducing the amount of phase B results in a tyrosinase inhibition rate of 63%, while the MITF inhibition rate under the action of phase A is 64%, and the melanin inhibition rate is 55%, which is close to the efficacy of a serum with the same ratio (Example 2). This proves that the change in formulation does not affect the synergistic effect of the two phases. The oil phase was adjusted to 10g of emulsifier and 120g of squalane. Although the transdermal penetration rate of 43% is slightly lower than that of the serum, the emulsion stability test showed no stratification, which is suitable for the needs of dry skin. The liposome loading rate is 90%, ensuring effective delivery of active ingredients.

[0035] Example 9: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an emulsion wherein A:B=1:3, the film material ratio is 6:1:0.8, and the tocopherol content is 8%; The preparation is the same as in Example 1, except that: Active ingredient composition: licorice extract 10.0g, bearberry extract 30.0g (A:B=1:3); Composite membrane material: Tocopheryl succinate 3.12g (8% of the total membrane material of 39g); Aqueous phase of emulsion: 180g of liposome suspension.

[0036] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Emulsion stability Transdermal rate 92% 128 73% 58% 60% No layering 42% In this embodiment, the ratio of A:B is 1:3. The high proportion of phase B results in a tyrosinase inhibition rate of 73%, combined with a 58% MITF inhibition rate, leading to a melanin inhibition rate of 60%. The 8% tocopherol succinate content is the highest among all embodiments, resulting in an active ingredient retention rate of 94%-95% and optimal stability. The amount of liposome suspension in the aqueous phase of the emulsion is increased to 180g, further enhancing the supply of active ingredients. The compatibility between the 128nm particle size and the 42% transdermal penetration rate ensures full efficacy. The absence of emulsion stratification demonstrates good physical stability.

[0037] Example 10: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an emulsion, wherein A:B=1:2, the film material ratio is 7:1:1, and the tocopherol content is 7%; The preparation is the same as in Example 1, except that: Composite membrane material: 35.0g hydrogenated soybean lecithin, 5.0g phytosterol, 5.0g ceramide, 3.15g tocopherol succinate (7% of the total membrane material of 45g); Emulsion viscosity: 2800 mPa·s.

[0038] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Emulsion stability Transdermal rate 89% 140 67% 62% 58% No layering 44% In this embodiment, the membrane material ratio is 7:1:1. The increased proportion of ceramides results in a liposome particle size of 140nm, and the transdermal penetration rate of 44% remains within the high-efficiency range. The 7% tocopherol succinate ensures stable retention of active ingredients and efficacy. The tyrosinase inhibition rate is 67%, the MITF inhibition rate is 62%, and the melanin inhibition rate is 58%. The emulsion viscosity is 2800mPa·s and there is no stratification when stored at 45°C, demonstrating the compatibility between the membrane material ratio and the emulsion formulation, taking into account both skin feel and stability.

[0039] Example 11: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an essence, wherein A:B=1:2, the film material ratio is 6:1:0.8, and the tocopherol content is 7%; The preparation is the same as in Example 1, except that: Composite membrane material: Tocopheryl succinate 2.73g (7% of the total membrane material of 39g); Glycerin content in the serum: 8%.

[0040] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 91% 122 68% 62% 59% 93% / 94% 43% In this embodiment, the proportion of tocopherol succinate was increased to 7%, and the retention rate of active ingredients reached 93%-94% after 6 months of storage at 45°C. This significantly improved the stability compared to Example 1 (6% tocopherol) without affecting the liposome loading rate (91%) and particle size (122nm). The proportion of glycerol in the essence was adjusted to 8%, which is within the limited range of 5-10%. The tyrosinase inhibition rate was 68%, the MITF inhibition rate was 62%, and the melanin inhibition rate was 59%. This indicates that the slight adjustment of the excipient ratio does not interfere with the synergistic effect of the biphasic components, demonstrating the compatibility of the formulation.

[0041] Example 12: Please see Figure 1 The present invention provides a technical solution: a method for preparing a topical skin care product, using an essence, wherein A:B=1:2, the film material ratio is 5:1:0.5, and the tocopherol content is 8%; The preparation is the same as in Example 1, except that: Composite membrane material: Tocopheryl succinate 2.6g (8% of the total membrane material of 32.5g); Homogenization times: 5.

[0042] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 92% 90 67% 64% 58% 94% / 95% 48% In this embodiment, the homogenization times were increased to 5 times, and with a membrane material ratio of 5:1:0.5, the liposome particle size was reduced to 90nm, and the transdermal permeability reached 48%, the highest among all embodiments. This facilitates the efficient delivery of active ingredients to the basal layer. The 8% tocopherol succinate content resulted in an active ingredient retention rate of 94%-95% and optimal stability. At an A:B ratio of 1:2, the tyrosinase inhibition rate of 67% and the MITF inhibition rate of 64% synergistically resulted in a melanin inhibition rate of 58%, confirming the synergistic effect of process parameter optimization (homogenization times) and component optimization (tocopherol content) on efficacy.

[0043] Comparative Example 1: Please see Figure 1 The present invention provides a comparative solution: an essence lacking phase A; S1: Preparation steps S1-1: Preparation of bearberry extract: Take 500g of dried bearberry leaves, pulverize to 20 mesh, add 1500mL of 55% ethanol, place in an ultrasonic extractor, set the temperature to 45℃ and the power to 300W, and ultrasonically extract for 75min. After extraction, filter with a 0.45μm organic filter membrane. Place the filtrate in a rotary evaporator and concentrate under reduced pressure at 50℃ and 0.08MPa to a paste (relative density 1.20, 25℃). Place the paste in a vacuum drying oven and dry at 60℃ and -0.09MPa for 8h to obtain 100g of bearberry extract. The bearberry extract contains 92% arbutin, with the remainder being 5% arbutin derivatives, 2% tannins, and 1% plant fiber residue. S2: Preparation of active ingredient composition: Accurately weigh 30.0g of bearberry extract (phase B, arbutin content 92%) using an electronic balance, place it in a stainless steel stirring jar, and stir at 300r / min for 15min to obtain 30.0g of active ingredient composition; S3: Liposome Preparation: Weigh 30.0g of hydrogenated soybean lecithin (purity ≥98%), 5.0g of phytosterol (purity ≥95%), 4.0g of ceramide (purity ≥90%), and 2.34g of tocopherol succinate (6% of the total membrane material mass of 39.0g), place them in a three-necked flask, add 200.0mL of anhydrous ethanol (analytical grade), and stir at 65℃ for 30min until dissolved; take 300.0mL of pH 5.8 phosphate buffer (0.05mol / L, phosphate is analytical grade), add 30.0g of the active ingredient composition and stir to dissolve; the membrane material solution is rotary evaporated at 55℃ and 0.09MPa for 1.5h to form a membrane, add the aqueous phase solution and stir at 65℃ for 35min to obtain the colostrum, homogenize 4 times at 800bar to obtain 320.0g of liposome suspension; S4: Preparation of the essence: Weigh 200.0g of liposome suspension, 50.0g of glycerin, 2.0g of sodium hyaluronate (molecular weight 1 million Da), 1.0g of xanthan gum, and 747.0g of deionized water. Stir at 50℃ for 30min until homogeneous. After cooling, adjust the pH to 6.0 to obtain 1000.0g of essence. The encapsulation rate was found to be 87%, the particle size was 130nm, and the viscosity at 25℃ was 1450mPa·s.

[0044] detection indicators Test results Liposome loading rate 87% Liposome particle size (nm) 130 Tyrosinase inhibition rate 70% MITF expression inhibition rate 12% Melanin content inhibition rate 30% Retention rate of active ingredients (arbutin) after 6 months of storage at 45℃ 90% Transdermal absorption rate 41% Skin irritation rating (0-5 points) 0.3 points In this comparative example, the MITF expression inhibition rate of the licorice extract (containing 48% glycyrrhizin A) lacking phase A was only 12%. Although the tyrosinase inhibition rate of the arbutin extract (containing 92% arbutin) of phase B reached 70%, the melanin content inhibition rate was only 30% due to the lack of upstream regulatory links, which was far lower than the 58% of Example 1. This directly confirms the necessity of the dual-target synergy of phase A and phase B. The liposome loading rate of 87% was slightly lower than that of Example 1, which is speculated to be due to the decreased membrane material compatibility when a single component is loaded. The transdermal absorption rate and irritation score were similar to those of Example 1, indicating that the absence of phase A does not affect the formulation delivery performance and mildness, but the efficacy is significantly weakened.

[0045] Comparative Example 2: Please see Figure 1 The present invention provides a comparative solution: an essence lacking phase B; Active ingredient composition: Contains only licorice extract phase A, including 48% glycyrrhizin chalcone A, 30% glycyrrhizic acid, 15% flavonoid derivatives, and 7% plant polysaccharides (30.0g), without phase B bearberry extract; The composite membrane material, liposome preparation process, essence excipient ratio and preparation steps are exactly the same as in Example 1.

[0046] detection indicators Test results Liposome loading rate 88% Liposome particle size (nm) 125 Tyrosinase inhibition rate 15% MITF expression inhibition rate 63% Melanin content inhibition rate 28% Retention rate of active ingredients (licorice chalcone A) after 6 months of storage at 45℃ 92% Transdermal absorption rate 42% Skin irritation rating (0-5 points) 0.3 points This comparative example retains only the A phase component from Example 1, and its MITF expression inhibition rate reaches 63%, which is basically the same as the 62% in Example 1, confirming the efficacy of A phase in targeting and regulating MITF; however, due to the lack of B phase inhibitory effect on tyrosinase, the tyrosinase inhibition rate is only 15%, and the final melanin content inhibition rate is only 28%, highlighting the limitations of the single A phase effect.

[0047] Comparative Example 3: Please see Figure 1 The present invention provides a comparative solution: an essence of a single membrane material; Preparation steps S1: Extract preparation: Same as in Example 1, 120g of licorice extract (48% licorice chalcone A content) and 100g of arbutin extract (92% arbutin content) were obtained; S2: Preparation of active ingredient composition: Weigh 10.0g of licorice extract (phase A, glycyrrhizin A content 48%) and 20.0g of arbutin extract (phase B, arbutin content 92%), stir and mix to obtain 30.0g of composition; S3: Liposome preparation: Weigh 39.0g of hydrogenated soybean lecithin (purity ≥98%) and 2.34g of tocopherol succinate, add 200.0mL of anhydrous ethanol (analytical grade), and stir at 65℃ for 30min until dissolved; take 300.0mL of pH 5.8 phosphate buffer (0.05mol / L, phosphate is analytical grade), add 30.0g of the composition and stir to dissolve; the membrane material solution is rotary evaporated at 55℃ and 0.09MPa for 1.5h to form a membrane, add aqueous solution and stir at 65℃ for 35min to obtain the colostrum, homogenize at 800bar 4 times to obtain 320.0g of liposome suspension; S4: Preparation of essence: Same as in Example 1, 1000.0g of essence was obtained, and the loading rate was 75%, the particle size was 280nm, and the viscosity at 25℃ was 1520mPa·s.

[0048] detection indicators Test results Liposome loading rate 75% Liposome particle size (nm) 280 Tyrosinase inhibition rate 45% MITF expression inhibition rate 40% Melanin content inhibition rate 35% Retention rate of active ingredients (glycyrrhizin chalcone A / arbutin) after 6 months of storage at 45℃ 72% / 75% Transdermal absorption rate 22% Skin irritation rating (0-5 points) 0.4 points This comparative example uses a single hydrogenated soybean lecithin membrane material (without phytosterols and ceramides). The liposome loading rate is reduced to 75%, and the particle size increases to 280nm, exceeding the 50-200nm transdermal range, resulting in a transdermal absorption rate of only 22%. Due to insufficient loading and lack of phytosterol stability regulation, the retention rate of phase A licorice extract (48% glycyrrhizin chalcone A content) and phase B arbutin extract (92% arbutin content) is only 72%-75% after 6 months of storage at 45℃. The inhibition rates of tyrosinase and MITF are significantly reduced, and the final melanin content inhibition rate is only 35%. The data show that the addition of phytosterols and ceramides is crucial to improving the liposome loading rate, stability, and transdermal properties. A single membrane material cannot achieve the efficacy of this technical solution.

[0049] Comparative Example 4: Please see Figure 1 The present invention provides a comparative solution: a serum without liposome encapsulation. Preparation steps S1: Extract preparation: Same as in Example 1, 120g of licorice extract (48% licorice chalcone A content) and 100g of arbutin extract (92% arbutin content) were obtained; S2: Preparation of active ingredient composition: Weigh 10.0g of licorice extract (phase A, glycyrrhizin A content 48%) and 20.0g of arbutin extract (phase B, arbutin content 92%), stir and mix to obtain 30.0g of composition; S3: Essence preparation: 30.0g of active ingredient composition was directly mixed with 50.0g of glycerin, 2.0g of sodium hyaluronate (molecular weight 1 million Da), 1.0g of xanthan gum, and 917.0g of deionized water. The mixture was stirred at 50℃ for 30min until homogeneous. After cooling, the pH was adjusted to 6.0 to obtain 1000.0g of essence. The viscosity at 25℃ was 1480mPa·s, and there was no liposome encapsulation.

[0050] detection indicators Test results Tyrosinase inhibition rate 30% MITF expression inhibition rate 25% Melanin content inhibition rate 20% Retention rate of active ingredients (glycyrrhizin chalcone A / arbutin) after 6 months of storage at 45℃ 60% / 65% Transdermal absorption rate 8% Skin irritation rating (0-5 points) 0.5 points In this comparative example, without liposome encapsulation, phase A licorice extract (48% glycyrrhizin A content) and phase B arbutin extract (92% arbutin content) were directly exposed in the formulation system. After storage at 45°C for 6 months, the retention rate was only 60%-65%, indicating severe oxidative degradation. Due to the lack of transdermal delivery by liposomes, the transdermal absorption rate was only 8%, making it difficult for the active ingredients to reach the basal layer of the skin. This resulted in a tyrosinase inhibition rate of 30%, a MITF expression inhibition rate of 25%, and a melanin content inhibition rate of only 20%, less than half of that in Example 1. The data clearly demonstrate that liposome encapsulation is the core means to improve the stability, transdermal permeability, and whitening efficacy of active ingredients. Without encapsulation, the technical effects of this invention cannot be achieved.

[0051] Comparative Example 5: Please see Figure 1 The present invention provides a comparative solution: an essence for membrane materials lacking phytosterols. Composite membrane material: 34.0g hydrogenated soybean lecithin, 4.0g ceramide (without phytosterols), 2.28g tocopheryl succinate (6% of the total membrane material of 38g); The rest is the same as in Example 1.

[0052] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 80% 220 50% 48% 38% 78% / 80% 28% This comparative composite membrane material lacks phytosterols, retaining only hydrogenated soybean lecithin and ceramides. The liposome loading rate drops to 80%, the particle size increases to 220 nm, and the transdermal penetration rate is only 28%. Due to insufficient loading and hindered delivery of active ingredients, the tyrosinase inhibition rate is 50%, the MITF inhibition rate is 48%, and the melanin inhibition rate is 38%. The retention rate at 45℃ is 78%-80%, and the stability is significantly reduced. The data prove that phytosterols play a key role in regulating membrane fluidity, improving loading rate and particle size uniformity. Without them, the core function of the carrier system cannot be achieved.

[0053] Comparative Example 6: Please see Figure 1 The present invention provides a comparative solution: a tocopherol succinate-free serum. Composite membrane material: only hydrogenated soybean lecithin 30.0g, phytosterol 5.0g, ceramide 4.0g (no tocopherol succinate); The rest is the same as in Example 1.

[0054] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 89% 130 52% 49% 40% 65% / 68% 41% This comparative composite membrane material, which is free of tocopherol succinate, showed normal liposome loading (89%) and particle size (130nm), and its transdermal permeability of 41% was not significantly affected. However, after 6 months of storage at 45°C, the retention rate of active ingredients was only 65%-68%, a significant decrease compared to Example 1 (92%-93%). The oxidative degradation of active ingredients directly resulted in a tyrosinase inhibition rate of 52%, an MITF inhibition rate of 49%, and a melanin inhibition rate of 40%. This clearly demonstrates the antioxidant and stabilizing effect of tocopherol succinate, and its absence leads to the inactivation of active ingredients, confirming the indispensability of this component in the long-term stability of the formulation.

[0055] Comparative Example 7: Please see Figure 1 The present invention provides a comparative solution: an essence of a low-purity extract. Phase A licorice extract: 35% glycyrrhizin A (balance: 35% glycyrrhizic acid, 18% flavonoids, 12% polysaccharides); Phase B bearberry extract: 85% arbutin content (balance 8% phenols, 4% tannins, 3% fiber); The rest is the same as in Example 1.

[0056] Liposome loading rate Particle size (nm) Tyrosinase inhibition rate MITF inhibition rate Melanin inhibition rate Retention rate at 45℃ for 6 months Transdermal rate 90% 128 45% 42% 32% 88% / 90% 42% This comparative example uses low-purity extracts: phase A contains 35% glycyrrhizin A and phase B contains 85% arbutin. Although the liposome loading rate (90%), particle size (128nm), and transdermal penetration rate (42%) are all normal, the insufficient content of effective active ingredients results in a tyrosinase inhibition rate of 45%, an MITF inhibition rate of 42%, and a melanin inhibition rate of only 32%. The data highlight the decisive influence of extract purity on efficacy, proving the rationality of limiting to high-purity extracts. Low-purity raw materials cannot achieve the expected effects of the invention.

[0057] A comprehensive analysis of the core data from Examples 1-12 and Comparative Examples 1-7 clearly demonstrates that this scheme employs a dual-target design, with licorice extract (phase A) targeting and inhibiting MITF transcription factor and bearberry extract (phase B), completely overcoming the limitations of single-target effects in existing technologies. In Examples 1-12, regardless of whether phase A and phase B are combined in a ratio of 1:1.5, 1:2, or 1:3, a melanin inhibition rate of 54%-62% is achieved. In Example 3, due to the 3-fold increase in the proportion of phase B, the tyrosinase inhibition rate reaches 75%, and the melanin inhibition rate climbs to 62%. Even in Example 4, which is an emulsion formulation, a melanin inhibition rate of 57% is maintained despite the liposome suspension ratio being reduced to 10%. In contrast, the lack of phase A in Comparative Example 1 results in a melanin inhibition rate of only 30%, directly confirming the non-obviousness and synergistic effect of the dual-target combination, thus solving the industry pain point of weak efficacy of existing single-component formulations. In the composite membrane materials, in Examples 1-12, after the membrane materials were compounded in a ratio of 5-7:1:0.5-1, the liposome loading rate remained stable at 89%-92%, and the particle size was controlled within the optimal transdermal range of 80-160 nm. After storage at 45°C for 6 months, the retention rate of active ingredients reached 89%-95%. In Example 12, due to the increase in homogenization times to 5 times and the tocopherol content reaching 8%, the particle size decreased to 90 nm, the transdermal rate increased to 48%, and the stability retention rate reached 95%. In contrast, in Comparative Example 2, the single membrane material, due to the lack of phytosterol for membrane fluidity regulation and ceramide for skin affinity optimization, experienced a sharp drop in loading rate to 75%, and the particle size increased to [missing information]. The transdermal penetration rate was only 22% and the stability retention rate was less than 75% for the 280nm particle size. The phytosterol loading rate of the comparative example 4 decreased to 80% with a particle size of 220nm and a transdermal penetration rate of only 28%. Although the tocopherol loading rate of the comparative example 5 reached 89%, the stability retention rate was only 65%-68%, and the active ingredient was severely oxidatively degraded. These data comparisons show that the formulation design of the composite membrane material is not a simple mixing of conventional components, but a precise optimization based on the functional requirements of the carrier. Its effect on improving loading efficiency, transdermal performance and stability far exceeds that of the single membrane material system, overcoming the inherent defects of traditional liposomes such as low drug loading, easy leakage and poor transdermal penetration. Meanwhile, by adjusting parameters such as homogenization pressure (800-1200 bar), tocopherol content (5%-8%), and excipient ratio, Examples 5-12 verified the stability and adaptability of the solution under different conditions. Whether it is a serum or an emulsion, it can maintain excellent performance, while the transdermal rate of Comparative Example 3 (without liposome encapsulation) is only 8%, and the melanin inhibition rate is only 20%, which is more than 3 times lower than that of the Examples. In summary, this technical solution, through multi-dimensional innovations such as dual-target component combination, composite membrane carrier, and high-purity raw material limitation, not only achieves a comprehensive surpassing of existing technologies in terms of efficacy, stability, and transdermal properties, but also forms a synergistic closed loop among the various innovative elements, including components, carrier, and process.

[0058] To further illustrate the beneficial technical effects of the whitening methods for inhibiting melanin production involved in the various embodiments of the present invention, relevant performance tests were conducted on the whitening methods for inhibiting melanin production involved in Examples 1-12 and Comparative Examples 1-7; the test methods are as follows: I. Liposome-related performance testing 1. Liposome loading rate test Sample preparation: Take 1 mL of liposome suspension, place it in a centrifuge tube, add 3 mL of anhydrous ethanol to break the membrane, vortex mix for 1 min to fully release the active ingredients; take another equal amount of suspension, centrifuge at 12000 r / min for 20 min, take 1 mL of supernatant, and dilute with 3 mL of anhydrous ethanol.

[0059] Detection procedure: High performance liquid chromatography (HPLC) was used to determine the total active ingredient content (A total) after membrane rupture and the free active ingredient content (A free) in the centrifuged supernatant. The detection conditions for glycyrrhizin A were: C18 column, mobile phase acetonitrile-0.1% phosphoric acid water (45:55), flow rate 1.0 mL / min, and detection wavelength 276 nm; the detection conditions for arbutin were: C18 column, mobile phase methanol-water (20:80), flow rate 0.8 mL / min, and detection wavelength 280 nm.

[0060] Calculation method: Load factor (%) = (Total A - Surfing A) / Total A × 100.

[0061] 2. Liposome particle size test Sample pretreatment: Take 0.1 mL of liposome suspension, dilute it with deionized water to 10 mL, vortex mix for 30 s to ensure that the sample is uniformly dispersed and free from agglomeration.

[0062] Detection process: A dynamic light scattering particle size analyzer was used, with the temperature set at 25℃ and the scattering angle at 90°. The diluted sample was injected into the detection cell and detected three times in a row, with each scan lasting 10 seconds. The average value was taken as the liposome particle size.

[0063] II. Whitening Efficacy Related Tests 1. Tyrosinase inhibition rate test Reagent preparation: Tyrosinase solution (200 U / mL, prepared with pH 6.8 phosphate buffer), L-tyrosine solution (0.5 mmol / L, prepared with the same buffer), sample solution (take the topical whitening preparation and dilute it with buffer to an active ingredient concentration of 0.1 mg / mL).

[0064] Reaction procedure: Add 50 μL of sample solution and 50 μL of tyrosinase solution to a 96-well plate sequentially, and incubate at 37°C for 10 min; add 50 μL of L-tyrosine solution and continue incubation for 30 min.

[0065] Detection and calculation: The absorbance (sample A) was measured at a wavelength of 475 nm using an ELISA reader. A blank group (sample replaced by buffer) and a control group (enzyme solution replaced by buffer) were set up. The inhibition rate (%) was calculated as [1 - (sample A - control A) / blank A] × 100.

[0066] 2. MITF expression inhibition rate test Cell culture: B16 mouse melanoma cells were cultured in DMEM medium containing 10% fetal bovine serum at 37°C in a 5% CO2 incubator until the logarithmic growth phase.

[0067] Sample preparation: Cells were seeded in 6-well plates (1×10⁻⁶ cells / well). 6 After culturing for 24 hours, culture medium containing the sample (final concentration of active ingredient 0.1 mg / mL) was added, and culture continued for another 48 hours; the control group was given culture medium without the sample.

[0068] Detection process: Cells were collected, total protein was extracted using RIPA lysis buffer, and protein concentration was measured using the BCA method; 20 μg of protein was taken for SDS-PAGE electrophoresis, transferred to a membrane and incubated with MITF antibody and β-actin antibody, and the band gray values ​​were analyzed using a gel imaging system after development.

[0069] Calculation method: MITF expression inhibition rate (%) = [1 - (gray value of sample group / gray value of β-actin in sample group) / (gray value of control group / gray value of β-actin in control group)] × 100.

[0070] 3. Melanin content inhibition rate test Cell treatment: B16 cells were seeded in 6-well plates (1×10⁻⁶ cells per well). 6 (samples / well), after culturing for 24 hours, add culture medium containing the sample (final concentration of active ingredient 0.1 mg / mL), and culture for 72 hours; the control group is given culture medium without the sample.

[0071] Detection procedure: Collect cells, wash twice with PBS, add 1 mol / L NaOH solution (containing 10% dimethyl sulfoxide), incubate at 80℃ for 30 min to dissolve melanin, centrifuge and collect the supernatant.

[0072] Detection and calculation: The absorbance of the microplate reader at 490nm was measured (sample A), and the absorbance of the control group was sample A. The inhibition rate (%) = [1 - (sample A / sample A)] × 100.

[0073] III. Stability Testing 1. Active ingredient retention rate test Sample storage: Take 50g of the topical whitening preparation, place it in a brown bottle, seal it, and put it in a 45℃ constant temperature incubator. Take samples at 0 days, 3 months, and 6 months.

[0074] Detection process: The sample was extracted with methanol by ultrasonication for 30 min, the supernatant was collected by centrifugation, and the contents of glycyrrhizin chalcone A and arbutin were determined by HPLC (detection conditions were the same as those for the inclusion loading test).

[0075] Calculation method: Retention rate (%) = (content after storage / initial content) × 100.

[0076] 2. Emulsion stability test Storage conditions: After sealing, the emulsion samples were placed in a 45℃ constant temperature incubator, a -20℃ freezer, and a room temperature (25℃) environment for 6 months.

[0077] Testing process: Regularly observe whether the sample shows phenomena such as layering, oil separation, clumping, discoloration, etc. Record the appearance after 6 months, and at the same time measure the viscosity change rate with a viscometer (≤15% is considered stable).

[0078] IV. Transdermal Absorption Rate Test Transdermal model: A Franz diffusion cell was used. 0.5 g of topical whitening agent was added to the supply chamber and 5 mL of pH 7.4 phosphate buffer was added to the receiving chamber. Fresh pig ear skin (subcutaneous fat removed, thickness 0.2 mm) was fixed between the two chambers and stirred at 37°C (500 r / min).

[0079] Sample collection: 1 mL of solution was collected from the receiving chamber at 2 h, 4 h, 8 h, 12 h and 24 h (with an equal amount of fresh buffer added at the same time).

[0080] Detection and calculation: The total amount of active ingredients in the receiving solution is determined by HPLC. Transdermal absorption rate (%) = (total content in the receiving chamber / initial content in the supply chamber) × 100.

[0081] V. Skin Irritation Test Volunteer selection: 30 healthy volunteers (aged 20-45, without skin diseases) will be recruited and divided into 3 groups of 10 people each.

[0082] Test method: Apply 0.02g of sample to a 3cm×3cm area on the inner forearm of the volunteer, cover and fix with gauze, and apply deionized water to the other side as a control. Remove the sample after 24 hours, and observe the skin reaction at 1h, 24h and 48h after removal.

[0083] Scoring criteria: Scoring is based on the redness, swelling, itching, and papules (0 points: no reaction; 1 point: slight redness; 2 points: obvious redness; 3 points: redness and swelling with itching; 4 points: redness and swelling, papules; 5 points: severe redness and swelling, blisters), and the average value is taken as the irritation score.

[0084] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for preparing an external skin care product, characterized by, The method comprises the following steps: S1: preparing an active ingredient composition, which comprises phase A and phase B; the phase A is a liquorice extract inhibiting MITF, a key transcription factor of melanin production, and the phase B is a bearberry extract inhibiting the activity of tyrosinase, and the mass ratio of the phase A to the phase B is 1:(1.5-3); S2: loading the active ingredient composition in a composite membrane material mixed liposome to obtain a liposome suspension with a loading rate of ≥88%, and the particle size of the liposome is 50-200 nm; S3: mixing the liposome suspension with cosmetic adjuvants to prepare a topical whitening preparation; S4: applying the topical whitening preparation on the skin surface, and through the transdermal penetration of the liposome, the components of the phase A and the phase B enter the skin basal layer to inhibit the expression of MITF and the activity of tyrosinase, respectively, and synergistically block melanin production.

2. The whitening method of claim 1, wherein, The mass content of liquorice chalcone A in the phase A liquorice extract is ≥45%, and the mass content of bearberry glycoside in the phase B bearberry extract is ≥90%.

3. The whitening method of claim 1, wherein, The composite membrane material in S2 is composed of hydrogenated soybean lecithin, phytosterol and ceramide with a mass ratio of (5-7):1:(0.5-1), and the liposome is prepared by a film dispersion-high pressure homogenization method; The specific steps are as follows: S1: dissolving the composite membrane material and tocopherol succinate in anhydrous ethanol, stirring at 60-70℃ until completely dissolved to form a membrane solution; S2: dissolving the active ingredient composition in a phosphate buffer with a pH of 5.5-6.0 to obtain an aqueous solution; S3: adding the membrane solution into a rotary evaporator, rotary evaporation at 50-60℃ under a vacuum degree of 0.08-0.1 MPa for 1-2 h to remove ethanol and form a uniform lipid film on the inner wall of the flask; S4: adding the aqueous solution into the flask, stirring at 60-70℃ for 30-40 min to form a preliminary emulsion; S5: placing the preliminary emulsion in a high-pressure homogenizer, homogenizing 3-5 times under a pressure of 800-1200 bar to obtain a liposome suspension.

4. The whitening method of claim 1, wherein, In the topical whitening preparation, the mass proportion of the liposome suspension is 10-30%, and the cosmetic adjuvants include glycerol, sodium hyaluronate, xanthan gum and deionized water, wherein the mass proportion of glycerol is 5-10%, the mass proportion of sodium hyaluronate is 0.1-0.5%, and the mass proportion of xanthan gum is 0.1-0.3%.

5. The whitening method of claim 1, wherein the composition is applied to the skin of the subject in an amount of about 0.1 to about 10 grams per square centimeter of skin. The dosage form of the topical whitening preparation is serum or emulsion.

6. The whitening method of claim 1, wherein, The amount of the external whitening preparation applied in S4 is 0.5-1 mg / cm 2 1-2 times a day, for ≥28 consecutive days.

7. The whitening method of claim 2, wherein the composition is applied to the skin of the subject in an amount of about 0.1 to about 10 grams per square centimeter of skin. The liquorice extract is prepared by the following method: taking dried liquorice roots, crushing them, and extracting them twice with 60-70% ethanol by reflux extraction, each time for 2-3 h, combining the extract, concentrating under reduced pressure until there is no alcohol taste, purifying with D101 macroporous resin, collecting the 60% ethanol eluate, and spray drying to obtain the liquorice extract.

8. The whitening method of claim 2, wherein, The bearberry extract is prepared by the following method: taking dried bearberry leaves, crushing them, and ultrasonically extracting them with 50-60% ethanol for 60-90 min, the extraction temperature being 40-50℃, filtering the extract through a 0.45 μm filter membrane, and concentrating under reduced pressure to a paste, and vacuum drying to obtain the bearberry extract.

9. The whitening method according to claim 3, characterized in that, The composite membrane material further comprises tocopherol succinate with a mass proportion of 5-8% of the total mass of the membrane material.

Images