A glabridin liposome, a whitening product, a preparation method and an application

Abstract

The present invention discloses a glabridin liposome, a whitening product, a preparation method and an application thereof, which relate to the technical field of cosmetics. The glabridin liposome of the present invention is made of the following components by mass percentage: 0.5%-2.5% of glabridin, 1%-8% of phospholipid, 0%-1% of cholesterol, 10%-15% of liquid oil, 0.5%-1.5% of emulsifier, 0.5%-1.5% of antioxidant, 0.2%-1% of trehalose, 10%-30% of glycerol and the balance of water. Through the innovation of the process and formula, the present invention solves the problems of the instability of glabridin, the non-uniformity of liposomes, etc., can not only improve the encapsulation rate, but also increase the transdermal absorption ability and stability, and improve the inhibitory activity against cell tyrosinase and melanin.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, and in particular to a glabridin liposome, a whitening product, a preparation method and an application thereof. Background Art

[0002] Glabridin is a unique isoflavone component in Glycyrrhiza glabra L., accounting for about 11% of the total flavonoid components in Glycyrrhiza glabra L. Glabridin has excellent whitening effects. It can penetrate deep into the skin and maintain high activity, effectively inhibiting the activities of various enzymes in the process of melanin production, especially inhibiting the activity of tyrosinase. At the same time, it also has the effects of preventing skin roughness and anti-inflammatory and antibacterial. Glabridin also has good antioxidant effects, showing strong anti-free radical oxidation effects. It can significantly inhibit the free radicals generated during the body's metabolism process, avoiding the oxidation damage of free radical-sensitive biological macromolecules and cell walls by free radicals, thereby playing a role in delaying cell aging. Therefore, it is widely used in skin care products. However, glabridin has defects such as low water solubility (the solubility is only 0.10 mg / L at 25°C), strong lipophilicity (logP = 4.85), and easy oxidation and degradation, with poor stability, resulting in its easy loss of activity in the preparation. In addition, glabridin is difficult to penetrate the skin barrier, and its transdermal absorption rate is relatively low, which limits its efficacy in skin care products.

[0003] The prior art usually adopts means such as adding penetration enhancers or new nano-preparation technologies (such as nanoemulsion, hydrogel, liposome, nanocrystal, cyclodextrin inclusion compound) to improve the water solubility of glabridin, enhance the stability or transdermal absorption rate. However, these technologies still have certain defects. For example, penetration enhancers can stimulate the skin. Especially when used at high concentrations or on sensitive skin types, it may cause redness, stinging or allergic reactions; nanoemulsion requires a high concentration of emulsifier, which stimulates the skin and is not resistant to dilution. If there is too much aqueous phase, it will affect the physicochemical properties of the nanoemulsion; the mechanical strength of the hydrogel is relatively low, it is easily damaged, has a low drug loading rate and an unstable release rate; the physical stability of nanocrystals is relatively poor, and there are phenomena such as aggregation and sedimentation, and crystal form transformation; cyclodextrin has a large molecular weight and is hydrophilic on the surface, and it is difficult to penetrate the stratum corneum composed of lipids; the particle size and structure of conventional liposomes may be uneven, the encapsulation rate is low, and it needs to be stored under low temperature and light protection conditions, otherwise it is easy to degrade or delaminate.

[0004] Chinese Patent CN118662374A discloses a glabridin liposome targeting melanocytes, its preparation method and application. The liposome is mainly made of the following components by mass percentage: phospholipid 1.0% - 5.0%, targeting phospholipid 0.05% - 0.25%, glabridin 1.0% - 2.0%, absolute ethanol 1.0% - 6.0%, cholesterol 0.1% - 0.2%, emulsifier 1.0% - 5.0%, co-emulsifier 0% - 20.0%, and water 61.55% - 95.85%. Among them, the emulsifier includes behenyl alcohol polyether-25; the targeting phospholipid includes DSPE-PEG-Nonapeptide-1. The liposome has small particle size, high homogeneity, high stability, is gentle to the human body and has a sustained release effect. The liposome carries a targeting phospholipid with a targeting molecule through covalent modification and encapsulates glabridin, which can specifically promote the absorption and effect of glabridin.

[0005] Due to the good structure and biocompatibility of liposomes, they are more likely to penetrate the skin barrier. Moreover, the bilayer membrane can protect the active ingredients contained therein from being damaged by light, oxygen or enzymatic hydrolysis, and can release drugs slowly, enabling the active ingredients to act continuously for a longer time, having relatively good advantages. At present, the research on the preparation of liposomes for glabridin is still very scarce. Summary of the Invention

[0006] In view of this, the present invention provides a glabridin liposome, a whitening product, its preparation method and application. Through innovation in technology and formulation, problems such as the instability of glabridin and the non-uniformity of liposomes are solved. It can not only improve the encapsulation efficiency, but also increase the transdermal absorption ability and stability, and enhance the inhibitory activity against cellular tyrosinase and melanin.

[0007] To achieve the above-mentioned invention purposes, the technical solutions of the present invention are as follows:

[0008] On the one hand, the present invention provides a glabridin liposome, which is made of the following components by mass percentage: glabridin 0.5% - 2.5%, phospholipid 1% - 8%, cholesterol 0% - 1%, liquid oil 10% - 15%, emulsifier 0.5% - 1.5%, antioxidant 0.5% - 1.5%, trehalose 0.2% - 1%, glycerol 10% - 30% and the balance water.

[0009] Among them:

[0010] The liquid oil is selected from at least one of glyceryl caprylate, polydimethylsiloxane, and rice bran oil;

[0011] The emulsifier is selected from at least one of sorbitan sesquioleate, polyethylene glycol monolauryl ether, and polyoxyethylene stearate;

[0012] The mass ratio of glabridin, liquid oil, emulsifier, antioxidant and trehalose is 0.5-2.5:10:1:0.5-1.5:0.5-1.

[0013] Preferably, the liquid oil is glyceryl caprylocaprate.

[0014] Preferably, the emulsifier is sorbitan sesquioleate.

[0015] Preferably, the antioxidant is selected from at least one of ascorbyl tetraisopalmitate and tocopheryl acetate, and more preferably ascorbyl tetraisopalmitate.

[0016] Preferably, the phospholipid is selected from at least one of hydrogenated lecithin, hydrogenated phosphatidylcholine, soybean lecithin, and egg yolk lecithin, more preferably at least one of hydrogenated lecithin and hydrogenated phosphatidylcholine, and most preferably hydrogenated lecithin.

[0017] Preferably, the mass ratio of glabridin, liquid oil, emulsifier, antioxidant and trehalose is 1.1:10:1:0.5:0.5.

[0018] More preferably, as the optimal implementation mode of the present invention, the mass ratio of glabridin, glyceryl caprylocaprate, sorbitan sesquioleate, ascorbyl tetraisopalmitate and trehalose is 1.1:10:1:0.5:0.5.

[0019] Preferably, the glabridin liposome is made of the following components in mass percentage: glabridin 1.1%, phospholipid 4.5%, cholesterol 1%, liquid oil 10%, emulsifier 1%, antioxidant 0.5%, trehalose 0.5%, glycerol 20% and the balance water.

[0020] Most preferably, the glabridin liposome is made of the following components in mass percentage: glabridin 1.1%, hydrogenated lecithin 4.5%, cholesterol 1%, glyceryl caprylocaprate 10%, sorbitan sesquioleate 1%, ascorbyl tetraisopalmitate 0.5%, trehalose 0.5%, glycerol 20% and the balance water.

[0021] On the other hand, the present invention provides a preparation method of the above glabridin liposome, comprising the following steps:

[0022] (1) Preparing an oil phase: Mixing and dissolving the formulated amounts of glabridin, phospholipid, cholesterol, liquid oil, emulsifier, and antioxidant to obtain an oil phase;

[0023] (2) Preparing an aqueous phase: Mixing the formulated amounts of trehalose, glycerol and water to obtain an aqueous phase;

[0024] (3) Mix the oil phase and the water phase to obtain a primary emulsion, and subject the primary emulsion to high-pressure homogenization treatment to obtain glabridin liposomes.

[0025] Preferably, in step (1), the temperature of the mixing and dissolving is 50 - 85 °C, and more preferably 80 °C.

[0026] As a specific example of the present invention, the mixing and dissolving is carried out with stirring in a water bath.

[0027] Preferably, in step (2), the temperature of the mixing is 50 - 85 °C, and more preferably 80 °C.

[0028] As a specific example of the present invention, the mixing is carried out with stirring in a water bath.

[0029] Preferably, in step (3), the mixing is specifically as follows: Add the oil phase to the water phase, stir while adding, after mixing evenly, continue to stir for 10 - 30 min at a rotation speed of 1000 - 3000 rpm to obtain a primary emulsion. As a specific example of the present invention, the mixing is specifically as follows: Add the oil phase to the water phase, stir while adding, after mixing evenly, continue to stir for 15 min at a rotation speed of 2000 rpm to obtain a primary emulsion.

[0030] Preferably, in step (3), the conditions of the high-pressure homogenization are: pressure 400 - 600 bar, number of times 4 - 12 times. As a specific example of the present invention, the conditions of the high-pressure homogenization are: pressure 600 bar, number of times 8 times.

[0031] On the other hand, the present invention provides a whitening product, including the above-mentioned glabridin liposomes or the glabridin liposomes prepared by the above-mentioned preparation method.

[0032] On the other hand, the present invention provides the application of the above-mentioned glabridin liposomes, the glabridin liposomes prepared by the above-mentioned preparation method or the above-mentioned whitening product in the preparation of cosmetics.

[0033] Preferably, the cosmetics include eye cream, face cream, primer, essence, lotion, toner, body lotion, facial mask liquid.

[0034] The beneficial effects of the present invention are as follows:

[0035] (1) Aiming at the component of glabridin, through the innovation of technology and formula, the present invention solves the problems of the instability of glabridin, the non-uniformity of liposomes, etc., can not only improve the encapsulation rate, but also increase the transdermal absorption ability and stability, and improve the inhibitory effect on the activity of cellular tyrosinase and melanin production.

[0036] (2) The present invention selects glabridin, specific liquid oils, specific emulsifiers, antioxidants and trehalose for compatibility, and at a specific ratio, has a synergistic effect, which can significantly improve the encapsulation efficiency, transdermal absorption ability, stability and inhibitory activity against cellular tyrosinase and melanin.

[0037] (3) It is found in the present invention that when the mass ratio of glabridin, glyceryl caprylate / caprate, sorbitan sesquioleate, ascorbyl tetraisopalmitate and trehalose is 1.1:10:1:0.5:0.5, the obtained liposomes have the best effect, significantly superior to other components and ratios. Description of the Drawings

[0038] Figure 1 It is a comparison chart of the particle size distribution of liposomal glabridin in Example 1 and commercially available liposomal glabridin.

[0039] Figure 2 It is a morphological diagram of the liposomal glabridin prepared in Example 1.

[0040] Figure 3 It is an in vitro release curve of glabridin and three kinds of liposomal glabridin.

[0041] Figure 4 It is an in vitro release curve of Example 1 and Comparative Example 2, Comparative Example 4, Comparative Example 6.

[0042] Figure 5 It is a schematic diagram of the working vertical diffusion cell.

[0043] Figure 6 It is a cumulative permeation amount curve of glabridin and three kinds of liposomal glabridin.

[0044] Figure 7 It is a change diagram of the particle size, potential, encapsulation efficiency, PDI of the liposomal glabridin in Example 1.

[0045] Figure 8 It is a result diagram of the relative activity of cellular tyrosinase of glabridin and the liposomes in Example 1;

[0046] In the figure, indicates a significant difference. Compared with the blank control group, P <0.01.

[0047] Figure 9 It is a result diagram of the relative content of cellular melanin of glabridin and the liposomes in Example 1;

[0048] In the figure, indicates a significant difference. Compared with the blank control group, P <0.01. Detailed Embodiments

[0049] The following non-limiting examples can enable those of ordinary skill in the art to more comprehensively understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary illustration of the scope claimed for the present invention. Those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes and modifications should also fall within the scope claimed in this application.

[0050] The present invention will be further described below by way of specific examples. All the various chemical reagents used in the examples of the present invention are obtained through conventional commercial channels unless otherwise specified. Unless otherwise specified, the contents described below are mass contents. Unless otherwise specified, it is understood to be carried out at room temperature.

[0051] In the following examples, the commercially available glabridin liposome 1 is branded as Sikexi, and the commercially available glabridin liposome 1 is branded as Fengtai.

[0052] In the following examples, the raw material sources are shown in Table 1:

[0053] Table 1

[0054]

[0055] Examples 1 - 2, Comparative Example 1

[0056] The formulations of Examples 1 - 2 and Comparative Example 1 are shown in Table 2:

[0057] Table 2

[0058]

[0059] Preparation method:

[0060] (1) Prepare the oil phase: Mix the formulated amounts of caprylic / capric triglyceride, emulsifier, antioxidant, glabridin, phospholipid, and cholesterol, and dissolve them by stirring in a water bath at 80°C to obtain the oil phase;

[0061] (2) Prepare the aqueous phase: Dissolve the formulated amounts of trehalose, glycerol, and water by stirring in a water bath at 80°C to obtain the aqueous phase;

[0062] (3) Add the oil phase to the aqueous phase, stir while adding, and after mixing evenly, continue to stir for 15 min at a rotation speed of 2000 rpm to obtain the primary emulsion. Then, subject the primary emulsion to high-pressure homogenization treatment, circulate and homogenize 8 times at a pressure of 600 bar, and the total duration of high-pressure homogenization is 5 min to obtain the glabridin liposome.

[0063] Example 3

[0064] The difference from Example 1 is that the liquid oil is polydimethylsiloxane, and the rest are the same.

[0065] Example 4

[0066] Different from Example 1, the liquid oil and fat is rice bran oil, and the rest are the same.

[0067] Example 5

[0068] Different from Example 1, the emulsifier is polyethylene glycol monolauryl ether, and the rest are the same.

[0069] Example 6

[0070] Different from Example 1, the emulsifier is polyoxyethylene stearate, and the rest are the same.

[0071] Example 7

[0072] Different from Example 1, the antioxidant is tocopheryl acetate, and the rest are the same.

[0073] Example 8

[0074] Different from Example 1, the phospholipid is hydrogenated phosphatidylcholine, and the rest are the same.

[0075] Example 9

[0076] Different from Example 1, the addition amount of trehalose is 0.2%, and the rest are the same.

[0077] Example 10

[0078] Different from Example 1, the addition amount of trehalose is 1%, and the rest are the same.

[0079] Comparative Example 2

[0080] Different from Example 1, the raw material formula is: glabridin 1.1%, hydrogenated lecithin 4.5%, cholesterol 1%, glyceryl caprylate / caprate 20%, sorbitan sesquioleate 0.5%, ascorbyl tetraisopalmitate 0.5%, trehalose 0.5%, glycerol 20% and the balance of water, and the rest are the same.

[0081] Comparative Example 3

[0082] Different from Example 1, trehalose is not added, and the rest are the same.

[0083] Comparative Example 4

[0084] Different from Example 1, the liquid oil and fat is glyceryl behenate, and the rest are the same.

[0085] Comparative Example 5

[0086] Different from Example 1, the liquid oil and fat is glyceryl monostearate, and the rest are the same.

[0087] Comparative Example 6

[0088] Differing from Example 1, the emulsifier is PEG-40 hydrogenated castor oil, and the rest are the same.

[0089] Comparative Example 7

[0090] Differing from Example 1, the emulsifier is behenyl alcohol polyether-25, and the rest are the same.

[0091] Result Detection:

[0092] 1. Determination of particle size, zeta potential and PDI

[0093] A nano particle size and zeta potential analyzer was used to determine the particle size, potential, and PDI (polydispersity index) of the liposomes. The results are shown in Table 3:

[0094] Table 3

[0095]

[0096] Examples of the particle size distributions of the glabridin liposomes prepared in Example 1 and commercially available glabridin liposomes are as Figure 1 shown. The particle size, potential, and PDI of the glabridin liposomes prepared in Examples 1-10 are all superior to those of Comparative Examples 1-7. Among them, the particle size of Example 1 is the smallest, 93.8 nm; the PDI is the smallest, 0.151, indicating that its particle size is more uniform. At the same time, the glabridin liposomes prepared in the present invention are significantly superior to commercially available glabridin liposomes.

[0097] 2. Encapsulation efficiency and drug loading

[0098] The microcolumn centrifugation method was used to determine the encapsulation efficiency of the glabridin liposomes. Preparation of the microgel column: Weigh a certain amount of Sephadex G-50, swell it with distilled water for 12 h, then load it into a 3 mL syringe without an inner plug (pack 3-5 mm of glass fiber at the bottom). After removing air bubbles, equilibrate it with distilled water for 2-3 column volumes, and centrifuge at 1000 r / min for 2 min. After centrifugation, the volume of the gel column is about 2 mL. Precisely pipette 0.2 g each of the liposome and drug solution (dissolved and fixed volume with methanol), slowly add it to the top of the column (note that when adding the sample, do not drip it on the edge of the column bed), centrifuge at 1000 r / min for 1 min to allow the sample to be measured to enter the microcolumn. Continue to add 1 mL of distilled water from the top of the column, repeat the elution, and collect 6 mL; after diluting the eluate with methanol, detect the content of glabridin and calculate the encapsulation efficiency.

[0099] Encapsulation efficiency = amount of drug in liposomes / total amount of drug × 100%

[0100] Drug loading = amount of drug in liposomes / sample mass × 100%

[0101] The results are shown in Table 4 as follows:

[0102] Table 4

[0103]

[0104] The liposomes prepared in the examples of the present invention are milky white liquids; the commercially available glabridin liposomes 1 are yellow transparent liquids; the commercially available glabridin liposomes 2 are light yellow pastes. The encapsulation efficiency, drug content, particle size, zeta potential and PDI of the liposomes prepared in the examples of the present invention are all superior to those of the commercially available liposomes.

[0105] The encapsulation efficiency of the glabridin liposomes prepared in Examples 1-10 is ≥80%, which meets the guiding principles for particulate preparations in Part IV of the Chinese Pharmacopoeia 2020 Edition. However, the encapsulation efficiency of the glabridin liposomes prepared in Comparative Examples 1-7 does not meet the requirements. Since the proportion of glabridin in Example 2 is relatively high, the drug loading is also relatively high, but the encapsulation efficiency is 82.4%, which meets the requirements but is lower than that of Example 1.

[0106] Meanwhile, the encapsulation efficiency and drug loading of the glabridin liposomes prepared in Examples 1-10 are superior to those of the commercially available glabridin liposomes.

[0107] 3. Morphological investigation

[0108] The morphology of the liposomes was observed by transmission electron microscopy and negative staining technique. 10 μL of the liposomes was pipetted onto a copper grid and allowed to precipitate for 1 min, and the floating liquid was blotted off with filter paper. Then 10 μL of phosphotungstic acid staining solution was pipetted onto the copper grid and allowed to precipitate for 1 min, and the floating liquid was blotted off with filter paper. After drying at room temperature for several minutes, electron microscopy detection and imaging were carried out at 80-120 kV, and observations were made under a transmission electron microscope, and images were collected for analysis.

[0109] The morphology of the liposomes prepared in Example 1 is as Figure 2 , the shape of the glabridin liposomes is round, with a bilayer structure, round edges, and good dispersibility.

[0110] 4. Determination of in vitro release ability

[0111] The dialysis bag method was used to investigate and compare the in vitro release behaviors of the liposome raw materials prepared by the optimal process and the commercially available raw materials of the control. The specific operations are as follows: A cellulose semi-permeable membrane was selected as the dialysis membrane, and 30% ethanol-saline was used as the release medium. 1 g of each test sample was placed in a dialysis bag, and both ends were sealed and placed in a conical flask containing 50 mL of the release medium. The mixture was shaken and released in a shaker at (37±0.5)°C and 100 r / min. Samples of 1 mL were taken at 1 h, 2 h, 4 h, 8 h, and 24 h, and 1 mL of fresh release medium at the same temperature was quickly added. The obtained samples were analyzed by HPLC and the cumulative release degrees of glabridin at different times were calculated.

[0112] The release curves of glabridin, the glabridin liposomes prepared in Example 1, and the commercially available glabridin liposomes are as Figure 3 shown. The release rates of the three kinds of glabridin liposomes at 0.5 h were all < 40%, and there was no burst release. The naked drug was released rapidly in the first 4 h, and the release rate reached 79.3%. Subsequently, the release rate became smaller, and it basically showed a stable state until 24 h later, and the final release rate was 84.3%. Within the first 4 h, at the initial stage of drug release of the glabridin liposomes, the drug attached to its surface was rapidly released, forming a slight burst release effect. Since the encapsulation rate of Fengtai glabridin liposomes was low, its release was faster. In the later stage, the drug release of the three kinds of liposomes was gentle, and the drug release rates after 24 h were 64.6%, 56.3% and 52.0% respectively. Compared with the glabridin group, the liposome group had a smaller release rate and a longer sustained release time. It shows that making glabridin into liposomes is beneficial to the sustained release effect of glabridin and increases the action time of glabridin.

[0113] The release curves of the glabridin liposomes prepared in Example 1, Comparative Example 2, Comparative Example 4 and Comparative Example 6 are as Figure 4 shown. The results show that the release rates of the four kinds of glabridin liposomes at 0.5 h were all < 40%, and there was no burst release; however, the glabridin liposomes prepared in Comparative Example 2, Comparative Example 4 and Comparative Example 6 were released faster in the early stage and tended to be gentle in the later stage; the release rate of the liposomes prepared in Example 1 was relatively uniform, the sustained release effect lasted for a long time, and it was more beneficial to the action time of the drug.

[0114] 5. Determination of transdermal absorption ability

[0115] The in vitro transdermal performance of liposomes was evaluated by the vertical Franz diffusion cell method (the working schematic diagram of the vertical diffusion cell is as Figure 5 ), and the in vitro transdermal performance of the liposome raw materials prepared by the optimal process and the commercially available raw materials of the control product was compared.

[0116] Bama minipig skin was selected for the experiment. The receiving solution was 30% ethanol - normal saline, the sample loading amount was 1 g, and samples were taken at 1 h, 2 h, 4 h, 8 h, and 24 h. At different time points, 0.5 mL of the receiving solution was aspirated with a syringe needle, and the same volume of isothermal fresh receiving solution was added in time. The receiving solution samples were centrifuged at 12000 r / min for 10 min, and the supernatant was taken for analysis.

[0117] (1) Cumulative permeation amount Q (μg / cm -2 ):

[0118] .

[0119] C n is the drug concentration in the receiving solution measured at the nth sampling point, C iCi is the drug concentration in the receiving solution measured at the i-th (≤ n - 1) sampling point, V is the total volume of the receiving solution, and Vi i is the volume of each sampling, and A is the effective diffusion area.

[0120] The release curves of glabridin, the glabridin liposomes prepared in Example 1, and the commercially available glabridin liposomes are as Figure 6 shown. The results show that the cumulative transdermal amount of each group of samples increases with the extension of time. After 24 h of treatment, the cumulative transdermal amount of the glabridin liposomes prepared in Example 1 of the present invention is the highest.

[0121] (2) Skin retention amount (μg / cm -2 ) :

[0122] At the end of the transdermal absorption test, the excised skin was taken down intact, rinsed thoroughly with warm normal saline, dried at room temperature, then cut into pieces and homogenized, added with 10 mL of methanol, ultrasonically extracted for 30 min, filtered through a 0.45 μm microporous membrane, and the skin retention amount was determined by HPLC method. The results are shown in Table 5:

[0123] Table 5

[0124]

[0125] The cumulative penetration amount and skin retention amount of the glabridin liposomes prepared in Examples 1 - 10 are higher than those of Comparative Examples 1 - 7, indicating that the glabridin liposomes prepared in Examples 1 - 10 have stronger transdermal absorption ability. At the same time, the encapsulation efficiency and drug loading of the glabridin liposomes prepared in Examples 1 - 10 are better than those of the commercially available glabridin liposomes.

[0126] The cumulative penetration amounts of Example 1, commercially available glabridin liposome 1, and commercially available glabridin liposome 2 are 2.94 times, 2.33 times, and 1.61 times that of free glabridin, respectively; the skin retention amounts are 1.98 times, 1.71 times, and 1.37 times that of free glabridin. The above results show that encapsulating glabridin in nano - liposomes can significantly improve its transdermal effect and increase the skin penetration and skin retention of glabridin; among them, the liposomes prepared in the examples of the present invention have better effects.

[0127] 6. Stability investigation

[0128] The liposomes prepared in Example 1 were stored at room temperature in the dark, and the particle size, zeta potential, PDI, and encapsulation efficiency (leakage rate) were detected at the 0th month (i.e., just prepared), 1st month, and 2nd month. The results of Example 1 are as Figure 7 shown.

[0129] Meanwhile, the stability in the cosmetic matrix was investigated. 5% by mass of liquiritigenin liposomes was added to the cosmetic emulsion. Under the condition of avoiding light at room temperature, the liquiritigenin content and the liposome encapsulation rate were measured at the 0th month (i.e., just after preparation) and the 2nd month. The results are shown in Table 6 as follows:

[0130] Table 6

[0131]

[0132] After adding the liposomes to the cosmetic emulsion matrix for 2 months, the degree of decrease in the encapsulation rate of the liquiritigenin liposomes prepared in Examples 1 - 10 was significantly lower than that in Comparative Examples 1 - 7. At the same time, it could protect the stability of liquiritigenin and reduce the loss of components.

[0133] 7. Whitening efficacy test

[0134] 1 Reagents and instruments

[0135] 1.1 Reagents

[0136] Mouse melanoma cells (B16 - F10 cells), fetal bovine serum, DMEM medium, etc.

[0137] 1.2 Instruments

[0138] Microplate reader, water bath, magnetic stirrer, electronic balance, etc.

[0139] 2 Experimental methods

[0140] 2.2 Cell tyrosinase activity

[0141] The cells were inoculated into 6 - well plates and divided into a cell normal control group and different concentration sample groups (containing different concentrations of samples). The cell control group was added with DMEM medium containing 10% fetal bovine serum, and the sample groups were added with medium and different concentrations of samples. The cells were collected, washed twice with PBS, centrifuged to discard the supernatant, lysed with 1 mL of 1% Triton X - 100, quickly placed in a - 80 °C refrigerator for 30 min, thawed at room temperature for about 20 min, mixed well and left to stand at 4 °C for 20 min, centrifuged to take the supernatant, 100 μL of the cell extract was taken into a 96 - well plate, 100 μL of L - levodopa solution was added and mixed well, incubated at 37 °C for 1 h, the OD475 was measured, and at the same time, the total protein P content (mg) in each well was measured using a BCA kit. The experiment was repeated 3 times. The calculation method of the melanin production inhibition rate is as follows:

[0142] .

[0143] 2.3 Cell melanin production

[0144] Cells were seeded in 6-well plates and divided into a normal cell control group and different concentration sample groups (containing different concentrations of the sample). The cell control group was added with DMEM medium containing 10% fetal bovine serum, and the sample groups were added with medium and different concentrations of the sample. The cells were collected, washed twice with PBS, centrifuged to discard the supernatant, and 1 mL of NaOH (1 mol / L) solution containing 10% DMSO was added, followed by a 1-hour water bath at 80 °C. 200 μL of the solution was taken and added to a 96-well plate to measure A400nm. The experiment was repeated 3 times, and the calculation method of the relative content of melanin production was as follows:

[0145] .

[0146] 3 Results and Analysis

[0147] 3.1 Cell safety results

[0148] The safe concentrations of free drug and liposome on B16-F10 cells are shown in Table 7.

[0149] Table 7

[0150]

[0151] 3.3 Results of cell tyrosinase activity

[0152] The inhibitory results of glabridin and the liposome of Example 1 on cell tyrosinase activity are shown in Figure 8 . The results show that both glabridin and the liposome of Example 1 have significant inhibitory effects on cell tyrosinase activity.

[0153] 3.4 Results of cell melanin production

[0154] The inhibitory results of glabridin and the liposome of Example 1 on cell melanin production are shown in Figure 9 . The results show that the glabridin raw material (purity 90%) and its liposome can significantly reduce the amount of melanin production.

[0155] The liposome was converted into free drug (about 100 times). The results show that at the same concentration, the liposome has higher ability to inhibit tyrosinase activity and inhibit melanin production than glabridin, because the liposome structure is similar to the cell membrane and is more likely to pass through the cell membrane and enter the cell to exert the whitening effect.

[0156] The measurement results of the glabridin liposomes prepared in Example 1 and Comparative Examples 2 - 7 at a dosage of 25 μg / mL are shown in Table 8:

[0157] Table 8

[0158]

[0159] The results showed that the glabridin liposomes prepared in Example 1 had the strongest inhibitory ability on the relative activity of cellular tyrosinase and also had the strongest effect on reducing the amount of cellular melanin production, indicating that the whitening effect was stronger than that of Comparative Examples 2-7.

Claims

1. A glabridin liposome, characterized in that: The invention is made of the following components in percentage by mass: 0.5%-2.5% glabridin, 1%-8% phospholipids, 0%-1% cholesterol, 10%-15% liquid oil, 0.5%-1.5% emulsifier, 0.5%-1.5% antioxidant, 0.2%-1% trehalose, 10%-30% glycerol and the balance water. in: The liquid oil is selected from at least one of caprylic / capric glyceride, polydimethylsiloxane, and rice bran oil; The emulsifier is selected from at least one of sorbitan sesquioleate, polyethylene glycol monolauryl ether, and polyoxyethylene stearate; The mass ratio of the glabridin, liquid oil, emulsifier, antioxidant and trehalose is 0.5-2.5:10:1:0.5-1.5:0.5-1.

2. The glabridin liposome according to claim 1, characterized in that The liquid oil is caprylic / capric glyceride.

3. The glabridin liposome according to claim 1, characterized in that The emulsifier is sorbitan sesquioleate.

4. The glabridin liposome according to claim 1, characterized in that The antioxidant is selected from at least one of ascorbyl tetraisopalmitate and tocopherol acetate.

5. The glabridin liposome according to claim 4, characterized in that The antioxidant is ascorbyl tetraisopalmitate.

6. The glabridin liposome according to claim 1, characterized in that The phospholipid is selected from at least one of hydrogenated lecithin, hydrogenated phosphatidylcholine, soybean lecithin and egg yolk lecithin.

7. The glabridin liposome according to claim 6, characterized in that The phospholipid is hydrogenated lecithin.

8. The glabridin liposome according to any one of claims 1 to 7, characterized in that: The mass ratio of the glabridin, liquid oil, emulsifier, antioxidant and trehalose is 1.1:10:1:0.5:0.

5.

9. The glabridin liposome according to claim 1, characterized in that The invention is prepared from the following components in percentage by mass: 1.1% of glabridin, 4.5% of phospholipids, 1% of cholesterol, 10% of liquid oil, 1% of emulsifier, 0.5% of antioxidant, 0.5% of trehalose, 20% of glycerol and the balance of water.

10. The glabridin liposome according to claim 9, characterized in that The glabridin liposome is made of the following components in percentage by mass: 1.1% glabridin, 4.5% hydrogenated lecithin, 1% cholesterol, 10% caprylic acid glyceride, 1% sorbitan sesquioleate, 0.5% ascorbyl tetraisopalmitate, 0.5% trehalose, 20% glycerol and the balance water.

11. The method for preparing the glabridin liposome according to any one of claims 1 to 10, characterized in that: The following steps are involved: (1) Preparing the oil phase: mixing and dissolving the formulated amounts of glabridin, phospholipids, cholesterol, liquid oil, emulsifier, and antioxidant to obtain the oil phase; (2) Preparing an aqueous phase: mixing the formulated amounts of trehalose, glycerol and water to obtain an aqueous phase; (3) The oil phase and the water phase are mixed to obtain a primary emulsion, and the primary emulsion is subjected to high pressure homogenization to obtain glabridin liposomes.

12. The preparation method according to claim 11, characterized in that: In step (3), the mixing is specifically as follows: adding the oil phase to the water phase, stirring while adding, and after mixing evenly, continuously stirring for 10-30 minutes at a rotation speed of 1000-3000 rpm to obtain a primary emulsion.

13. The preparation method according to claim 11, characterized in that: In step (3), the conditions of high pressure homogenization are: pressure 400-600 bar, number of times 4-12 times.

14. A whitening product, characterized in that: The invention comprises the glabridin liposome according to any one of claims 1 to 10, or the glabridin liposome prepared by the preparation method according to any one of claims 11 to 13.

15. Use of the glabridin liposome according to any one of claims 1 to 10, or the glabridin liposome prepared by the preparation method according to any one of claims 11 to 13, or the whitening product according to claim 14 in the preparation of cosmetics.

16. The use according to claim 15, characterized in that The cosmetics include eye cream, face cream, primer, essence, lotion, toner and facial mask liquid.

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