CN113520892B - Aqueous composition of glabridin and preparation method thereof - Google Patents

Abstract

The invention relates to an aqueous composition of glabridin and a preparation method thereof. The composition comprises the following components: 0.1 to 5.0 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 5.0 to 50.0 weight percent of amphiphilic humectant, 0 to 5.0 weight percent of O/W emulsifier and the balance of water. The composition does not need heating in the preparation process, has simple and energy-saving process, reduces the dosage of the emulsifying agent, has low irritation, fresh and cool skin feel, is moist and non-sticky, and has good permeability and absorption and good stability. Can be directly added into water or emulsion cosmetics as ingredients, improves the convenience of glabridin use, and exerts the efficacy to the greatest extent.

Description

Aqueous composition of glabridin and preparation method thereof

Technical Field

The invention relates to an aqueous composition of functional components and a preparation method thereof, in particular to an aqueous composition of glabridin and a preparation method thereof.

Background

Glabridin is a natural high-efficiency whitening factor extracted from Glycyrrhiza glabra, and mainly inhibits melanin production by inhibiting active oxygen production and tyrosinase activity. Since glabridin is expensive and excellent in whitening effect, glabridin is known as whitening gold.

The biggest limitation of glabridin application in skin care products is water insolubility. For aqueous formulations, such as facial masks, aqueous essences, lotions, it is difficult to directly add glabridin. This property of glabridin limits its use in skin care products.

Reference 1 (CN 108815012 a) discloses a preparation method of water-soluble glabridin, which adopts a microcapsule coating agent alpha-cyclodextrin technology, and the prepared water-soluble glabridin powder is very easily dissolved in purified water at normal temperature, and no additional treatment is needed, so that the application range of glabridin is greatly improved. However, the glabridin raw material obtained by the technology can be prepared into transparent water aqua products only under the condition of extremely low addition amount. When the addition amount is large, sticky skin feel can be brought, and the cost is relatively high.

Microemulsions are transparent or translucent, isotropic thermodynamically stable systems that are spontaneously formed from water, oil, surfactant and cosurfactant in appropriate proportions. In recent years, the microemulsification technology is increasingly applied to efficacy type skin care products, and mainly plays roles in solubilization, permeation and slow release of active substances. The main reason is that the diameter of pores on the skin of the human body is only 60nm, the particle size of the microemulsion disperse phase liquid beads is generally 10-100 nm, and the active ingredients can penetrate into deep dermal tissues through pores under the help of the microemulsion technology, thereby being beneficial to exerting the efficacy. However, microemulsion technology itself has drawbacks such as generally, the amount of surfactant required to form a microemulsion system is large, thereby causing adverse reactions such as skin irritation, allergy, and the like. In addition, the surfactants currently available for preparing the microemulsion system are relatively few, and the composition and the proportion of the surfactants are not thoroughly studied.

The bicontinuous phase microemulsion (BiContinuous MicroEmulsion, BCME for short) is an intermediate transition phase which occurs during the mutual transition of the oil-in-water microemulsion and the water-in-oil microemulsion. The bicontinuous phase microemulsion has a strong solubilizing ability and a large interfacial area relative to the droplet type microemulsion. BCME is currently mainly used in the development of makeup removal products because it has both hydrophilicity and lipophilicity, has good compatibility with cosmetic stains, can easily wash the cosmetic stains, and provides a fresh feel after use. In addition, BCME is also used in sunscreen compositions, but the amount of surfactant used in bicontinuous phase microemulsion compositions is increased compared to conventional oil-in-water emulsions and water-in-oil emulsions, and the light and thin feeling of use is impaired. Therefore, there is still a need for further development and improvement of the composition of BCME and its application.

Prior art literature

Patent document 1: CN108815012A

Disclosure of Invention

Problems to be solved by the invention

The invention provides an aqueous composition of glabridin, a preparation method thereof and a cosmetic containing the composition, wherein the composition can solve the problem that the glabridin is difficult to apply in an aqueous skin care product, and the obtained composition has good use feeling (quick absorption speed, moist feeling in the absorption process, no sticky feeling after absorption), stability and low irritation. The preparation method has the advantages of no need of heating in the preparation process, simple process, energy consumption saving and low cost.

Solution for solving the problem

In order to solve the above problems, the inventors have found that, by compounding the O/W emulsifier and the amphiphilic humectant of the present invention, or by using the amphiphilic humectant of the present invention, bicontinuous phase microemulsion of glabridin can be successfully obtained, and by forming bicontinuous phase microemulsion of glabridin, it is ensured that glabridin can be dissolved in water very easily at normal temperature, for example, it can be applied to aqueous products having high transparency and fresh skin feel. The invention also reduces the dosage of the emulsifying agent, which reduces the occurrence of adverse reactions such as skin irritation, allergy and the like. And the process for preparing the composition does not need heating, the process is simple, the energy consumption is saved, and the cost is low. That is, the present invention provides a scheme for preparing an aqueous glabridin composition comprising: 0.1 to 5.0 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 5.0 to 50.0 weight percent of amphiphilic humectant, 0 to 5.0 weight percent of O/W emulsifier and the balance of deionized water.

The composition comprises greater than 0wt% of the O/W emulsifier.

The polyhydric alcohol is a dihydric or higher alcohol, preferably a dihydric or trihydric alcohol. The number of carbon atoms of the polyol is, for example, 2 to 10, preferably 2 to 6.

The polyalcohol comprises one or more than two of 1, 2-pentanediol, butanediol, propylene glycol, dipropylene glycol and glycerol. Preferably, the polyol is one or a mixture of two of 1, 2-pentanediol and butanediol.

The amphiphilic humectant is one or a mixture of more than two components of PEG/PPG copolymer or derivatives thereof. Preferably, the amphiphilic humectant is PEG/PPG copolymer or a derivative thereof, and the content is 20-50 wt%.

The O/W emulsifier comprises one or a mixture of more than two of HLB values ranging from 8 to 18. The O/W emulsifier comprises one or more than two of polyoxyethylene type surfactant and ethylene oxide-propylene oxide block copolymer.

Preferably, the purity of glabridin is 99% or more.

The preparation method of the composition comprises the following steps:

(1) Weighing glabridin, polyalcohol, amphiphilic humectant, O/W emulsifier and deionized water according to weight percentage;

(2) Mixing the polyol, amphiphilic humectant and O/W emulsifier;

(3) Adding the glabridin powder into the solution obtained in the step (2), and stirring until the glabridin powder is completely dissolved;

(4) Adding a proper amount of water into the solution obtained in the step (3) to form bicontinuous phase microemulsion;

(5) Adding the remaining water to the solution obtained in (4) to obtain the composition.

The invention also provides a cosmetic, which comprises the aqueous composition of glabridin. The invention also relates to the use of said aqueous composition for the preparation of cosmetics.

ADVANTAGEOUS EFFECTS OF INVENTION

Compared with the prior art, the composition obtained by the invention does not need heating in the preparation process, has simple process, saves energy consumption, reduces the dosage of the emulsifying agent, has low irritation, fresh and cool skin feel, is moist and non-sticky, and has good osmotic absorption and stability. Can be directly added into water or emulsion cosmetics as ingredients, improves the convenience of glabridin use, and exerts the efficacy to the greatest extent.

Drawings

Fig. 1 is a result of BCME status formation in example 3 of the present application.

Detailed Description

The following detailed description of specific embodiments of the invention is, but it should be understood that the invention is not limited to specific embodiments.

[ aqueous composition of glabridin ]

The aqueous composition of glabridin of the present invention comprises: 0.1 to 5.0 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 5.0 to 50.0 weight percent of amphiphilic humectant, 0 to 5.0 weight percent of O/W emulsifier and the balance of deionized water.

< glabridin powder >

Glabridin (alias: licoflavone, glabridin; english name: glabridin) is one of main flavonoid components in Glycyrrhiza glabra.

Glabridin is a natural whitening agent separated from licoflavone, and the licoflavone is extracted from rhizomes of specific variety of licorice plants (such as uralensis, glycyrrhiza distenosa, glycyrrhiza glabra, etc.), and has the advantages of no pollution, no side effects on human body, and no pollution. Light yellow to reddish brown powder at normal temperature, is insoluble in water, and is easily dissolved in organic solvents such as ethanol, propylene glycol, 1, 3-butanediol, etc. Glabridin has strong antibacterial, ultraviolet-induced inflammation, pigmentation and rough skin preventing effects, can remove superoxide ions, inhibit hemolysis caused by hydrogen peroxide, can inhibit tyrosinase activity, can inhibit dopachrome interconversion and DHICA oxidase activity, is a rapid, efficient and green whitening and freckle-removing cosmetic additive, has the similar capability of removing oxygen free radicals as SOD (superoxide dismutase), and has the similar capability of resisting oxygen free radicals as vitamin E. In addition, glabridin has strong oxidation effect, anti-atherosclerosis and certain effects of reducing blood fat and blood pressure.

The amount of glabridin used in the present invention is 0.1wt% to 5.0wt%, and if the amount of glabridin is less than 0.1wt%, it is difficult to bring about remarkable effects by adding the composition of the present invention to a cosmetic formulation in conventional amounts, and if the amount of glabridin is more than 5wt%, it is necessary to greatly increase the amount of emulsifier, the irritation of the composition increases, and the cost is excessively high. Preferably, the content is 0.3wt% to 4.0wt%, further preferably, the content is 0.5wt% to 3.0wt%, still further preferably, the content is 1.0wt% to 2.0wt%, and as the content of glabridin used in the present invention, for example, there may be exemplified: 0.2wt%, 0.4wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.5wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%.

< polyol >

The polyhydric alcohol used in the present invention is a dihydric or higher alcohol, preferably a dihydric or trihydric alcohol. The number of carbon atoms of the polyol is, for example, 2 to 10, preferably 2 to 6.

Examples of the polyhydric alcohol include ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, dipropylene glycol, glycerin, and the like, and preferably butylene glycol and 1, 2-pentylene glycol.

As the polyhydric alcohol, 1 or 2 or more selected from them may be used singly or simultaneously. For example, a mixed solution composed of 25 to 75% by mass of butanediol and 75 to 25% by mass of 1, 2-pentanediol can be used.

The polyol used in the present invention is contained in an amount of 2.0 to 25wt%, if the content is less than 2.0wt%, the preservative ability of the composition of the present invention is insufficient, and if the content is more than 25.0wt%, the irritation of the composition of the present invention is increased, preferably, the content is 3.0 to 10.0wt%, more preferably, the content is 4.0 to 8.0wt%, still more preferably, the content is 5.0 to 7wt%. As the content of the polyol used in the present invention, there may be mentioned, for example: 6wt%, 9wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt%.

< amphiphilic humectant >

The amphiphilic humectant used in the present invention is a humectant having a hydrophilic lipophilic group, and examples thereof include a PEG/PPG copolymer or a mixture of one or two or more components thereof. The PEG/PPG copolymer is a product of EO (ethylene oxide) and PO (propylene oxide) which are randomly polymerized, the surface activity is not shown, and the derivative is a product obtained by reacting the PEG/PPG copolymer with methanol or polyalcohol compounds.

Preferably, the amphiphilic humectant comprises one or more of PEG/PPG-17/6 copolymer, PEG/PPG-18/4 copolymer, PEG/PPG-14/7 dimethyl ether, PEG/PPG-17/4 dimethyl ether, PEG/PPG/polybutylene glycol-8/5/3 glycerin.

The content of the amphiphilic humectant used in the present invention is 5.0wt% to 50.0wt%, and if the content is less than 5.0wt%, the effect of reducing the amount of the surfactant cannot be exerted, and if the content is more than 50.0wt%, the cost cannot be taken into consideration. Preferably, the content is 10.0wt% to 40.0wt%, further preferably, the content is 15.0wt% to 35.0wt%, still further preferably, the content is 20wt% to 30wt%. The content of the amphiphilic humectant used in the present invention may be, for example: 6wt%, 7wt%, 8wt%, 9wt%, 11wt%, 12wt%, 13wt%, 14wt%, 16wt%, 17wt%, 18wt%, 19wt%, 21wt%, 22wt%, 23wt%, 24wt%, 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 31wt%, 32wt%, 33wt%, 34wt%, 36wt%, 37wt%, 38wt%, 39wt%, 41wt%, 42wt%, 43wt%, 44wt%, 45wt%, 46wt%, 47wt%, 48wt%, 49wt%.

Preferably, the content ratio of the glabridin powder to the amphiphilic humectant is 1:300-1:10, more preferably, the content ratio of the glabridin powder to the amphiphilic humectant is 1:200-1:10, still more preferably, the content ratio of the glabridin powder to the amphiphilic humectant is 1:50-1:10. As the content ratio of glabridin powder to the amphiphilic humectant used in the present invention, there can be exemplified, for example: 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20, 1:21, 1:22, 1:23, 1:24, 1:25, 1:26, 1:27, 1:28, 1:29, 1:30, 1:31, 1:32, 1:33, 1:34, 1:35, 1:36, 1:37, 1:38, 1:39, 1:40, 1:41, 1:42, 1:43, 1:44, 1:45, 1:46, 1:47, 1:48, 1:49, 1:60, 1:70, 1:80, 1:90, 1:100, 1:110, 1:120, 1:130, 1:140, 1:150, 1:160, 1:170, 1:180, 1:190, 1:210, 1:220, 1:230, 1:240, 1:280, 1:250, 1:260, 1:270, 1:260.

< O/W emulsifier >

The O/W emulsifier used in the present invention includes a mixture of one or two or more of HLB values of 8 to 18.

Examples of the O/W emulsifier used in the present invention include one or a mixture of two or more of a polyoxyethylene surfactant and an ethylene oxide-propylene oxide block copolymer.

Preferably, one or a mixture of two or more of PPG-13-decyl tetradecyl polyether-24, PPG-26-butanol polyether-26, PEG-40 hydrogenated castor oil, and PEG-60 hydrogenated castor oil is used.

The O/W emulsifier used in the present invention is preferably contained in an amount of 0wt% to 5.0wt% in order to reduce the irritation of the emulsifier to the skin as low as possible, and if the content is controlled to 5.0wt% or less in consideration of cost and the like, the skin irritation can be reduced and the dissolution of glabridin into water can be promoted. Preferably, the content is more than 0wt%, more preferably the content is 1.0wt% to 4.0wt%, and as the content of the O/W emulsifier used in the present invention, for example, there may be exemplified: 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1.1wt%, 1.2wt%, 1.3wt%, 1.4wt%, 1.5wt%, 1.6wt%, 1.7wt%, 1.8wt%, 1.9wt%, 2.0wt%, 2.1wt%, 2.2wt%, 2.3wt%, 2.4wt%, 2.5wt%, 2.6wt%, 2.7wt%, 2.8wt%, 2.9wt%, 3.0wt%, 3.1wt%, 3.2wt%, 3.3wt%, 3.4wt%, 3.6wt%, 3.7wt%, 3.8wt%, 3.9wt%, 4.1wt%, 4.2wt%, 4.3wt%, 4.4wt%, 4.5wt%, 4.6wt%, 4.7wt%, 4.8wt%, 4.9wt%.

Preferably, the content ratio of the glabridin powder to the O/W emulsifier is 1:3-5:1, more preferably, the content ratio of the glabridin powder to the O/W emulsifier is 1:2-5:1.5, still more preferably, the content ratio of the glabridin powder to the O/W emulsifier is 1:1-5:2. The content ratio of glabridin powder to O/W emulsifier used in the present invention may be, for example: 5:3, 5:4, 2:1, 4:3, 4:1, 3:2, 3:1.

[ Water ]

The water used in the present invention includes purified water, distilled water, ion-exchanged water, and the like.

[ bicontinuous phase microemulsion ]

The bicontinuous phase microemulsion is prepared by mixing the polyalcohol, the O/W emulsifier, the amphiphilic humectant, the glabridin powder and a proper amount of water.

[ aqueous composition of glabridin ]

The aqueous composition of glabridin of the present invention is prepared by further mixing the bicontinuous microemulsion formed as described above with water. The composition of the invention has good antiseptic ability due to the use of the polyol, is convenient to store, and can be used as a cosmetic ingredient according to the need.

In specific examples, the following aqueous compositions of glabridin can be exemplified, for example: an aqueous composition of glabridin comprising: 0.1 to 0.3 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 5.0 to 50.0 weight percent of amphiphilic humectant and the balance of deionized water. For another example: an aqueous composition of glabridin comprising: 0.1 to 1.0 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 5.0 to 50.0 weight percent of amphiphilic humectant, more than 0 weight percent and less than 1.0 weight percent of O/W emulsifier and the balance of deionized water. For another example: an aqueous composition of glabridin comprising: 0.1 to 5.0 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 5.0 to 50.0 weight percent of amphiphilic humectant, 1.0 to 5.0 weight percent of O/W emulsifier and the balance of deionized water.

[ cosmetics ]

In the cosmetic of the present invention, in addition to the aqueous composition containing glabridin according to the present invention, raw materials commonly used in cosmetics may be appropriately blended as required. The raw materials are not particularly limited as long as the objects of the present invention are not impaired, and examples thereof include moisturizers, oily components, tackifiers, emulsifiers, preservatives, antioxidants, pH adjusters, perfumes, other skin care components, and the like.

[ preparation method of aqueous glabridin composition ]

As a method for preparing the aqueous composition of glabridin of the present invention, the preparation method comprises the steps of:

(1) Weighing the glabridin, the polyol, the amphiphilic humectant, the O/W emulsifier and the deionized water according to the weight percentage;

(2) Mixing the polyol, amphiphilic humectant and O/W emulsifier;

(3) Adding the glabridin powder into the solution obtained in the step (2), and stirring until the glabridin powder is completely dissolved;

(4) Adding a proper amount of water into the solution obtained in the step (3) to form bicontinuous phase microemulsion;

(5) Adding the remaining water to the solution obtained in (4) to obtain the composition.

The preparation process does not need heating, and has simple process and energy consumption saving.

The raw materials used in the invention are all common raw materials for cosmetics, can be obtained commercially, do not need subsequent treatments such as purification and the like, have simple process, and can save time and resources.

Examples

Example 1

The method for preparing the aqueous composition of glabridin of the present invention comprises:

3.0g of 1, 2-pentanediol, 0.2. 0.2g Solubilisant LRI (composition: PPG-26-butanol polyether-26, PEG-40 hydrogenated castor oil), 22.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol were mixed.

0.1g glabridin powder was added to the above solution and stirred until it was completely dissolved.

To the above solution, 3.0g of water was added and mixed well to form a BCME state.

Adding the solution into the rest 71.7g of water, and uniformly mixing to obtain the product, namely the glabridin aqueous composition.

Example 2

(in this example, PPG-13-decyl tetradecyl polyether-24 is replaced by PEG-60 hydrogenated castor oil)

6.0g of 1, 2-pentanediol, 1.0g of PPG-13-decyl tetradecyl polyether-24, 30.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol are mixed.

1.0g of glabridin powder was added to the above solution, and stirred until it was completely dissolved.

To the above solution, 4.0g of water was added and mixed well to form a BCME state.

Adding the solution into the rest 58.0g of water, and uniformly mixing to obtain the product, namely the glabridin aqueous composition.

Example 3

The PEG/PPG/polytetramethylene glycol-8/5/3 glycerin of example 2 was replaced with a PEG/PPG-17/6 copolymer, and the other parameters and steps were the same as in example 2. The final product was an aqueous composition of glabridin according to the invention.

Example 4

5.0g of butanediol, 4.0. 4.0g Solubilisant LRI (composition: PPG-26-butanol polyether-26, PEG-40 hydrogenated castor oil), 25.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol were mixed.

Adding 2.0g glabridin powder into the above solution, stirring to dissolve completely.

To the above solution, 4.0g of water was added and mixed well to form a BCME state.

Adding the solution into the rest 60.0g of water, and uniformly mixing to obtain the product, namely the glabridin aqueous composition.

Example 5

5.0g of butanediol, 2.0g of 1, 2-pentanediol, 1.50g of PPG-13-decyl tetradecyl polyether-24, 50.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol were mixed.

5.0g of glabridin powder was added to the above solution, and stirred until it was completely dissolved.

To the above solution, 5.0g of water was added and mixed well to form a BCME state.

Adding the solution into the rest 31.5g of water, and uniformly mixing to obtain the product, namely the glabridin aqueous composition.

Example 6

5.0g of butanediol, 2.0g of 1, 2-pentanediol, 50.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol were mixed.

0.3g glabridin powder was added to the above solution and stirred until it was completely dissolved.

To the above solution, 5.0g of water was added and mixed well to form a BCME state.

Adding the solution into the rest 37.7g of water, and uniformly mixing to obtain the product, namely the glabridin aqueous composition.

Comparative example 1

5.0g of butanediol, 2.0g of 1, 2-pentanediol, 1.5g of PPG-13-decyl tetradecyl polyether-24 are mixed. 5.0g of glabridin powder was added to the above solution, and stirred until it was completely dissolved.

To the above solution, the remaining 86.5g of water was added and mixed. Glabridin is precipitated as white lump, and can not be dissolved.

Comparative example 2

5.0g of butanediol, 2.0g of 1, 2-pentanediol, 22.5g of PPG-13-decyl tetradecyl polyether-24 are mixed.

5.0g of glabridin powder was added to the above solution, and stirred until it was completely dissolved.

To the above solution, the remaining 65.5g of water was added and mixed. A transparent solution was formed, but the solution was viscous and poor in skin feel.

Comparative example 3

6.0g of 1, 2-pentanediol, 1.0g of PPG-13-decyl tetradecyl polyether-24, 4.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol are mixed.

1.0g of glabridin powder was added to the above solution, and stirred until it was completely dissolved.

To the above solution, 4.0g of water was added and mixed well.

The above solution was added to the remaining 84.0g of water and mixed with stirring, and the resulting sample was a cloudy emulsion.

Comparative example 4

6.0g of 1, 2-pentanediol, 1.0g of PEG-7 glycerol cocoate, 30.0g of PEG/PPG/polytetramethylene glycol-8/5/3 glycerol were mixed.

1.0g of glabridin powder was added to the above solution, and stirred until it was completely dissolved.

To the above solution, 4.0g of water was added and mixed well.

The above solution was added to the remaining 58.0g of water and mixed with stirring, and the resulting sample was a cloudy emulsion. The above method for confirming the formation of bicontinuous phase microemulsion (BCME) is: the water-soluble pigment (yellow) and the oil-soluble pigment (blue) were added to the sample to be confirmed, respectively, and if both the water-soluble pigment and the oil-soluble pigment were uniformly dispersed in the sample, it was confirmed that the BCME state was formed. If either or both of the water-soluble dye and the oil-soluble dye cannot be uniformly dispersed in the sample, it can be confirmed that the BCME state is not formed.

Results

The embodiments of examples 1-6 of the present application use less O/W emulsifier, even at zero O/W emulsifier, to set the glabridin to BCME and form a clear aqueous glabridin composition even with the addition of a significant amount of water.

Comparative examples 1 and 3 to 4, although O/W emulsifiers were used, did not set the Glycyrrhiza glabra to a clear aqueous composition when a large amount of water was added, indicating that instead of using an O/W emulsifier with solubilization, the glabridin powder was dissolved in an aqueous medium and brought to a clear state, and an amphipathic humectant was added at the same time in a proper ratio. Although comparative example 2 uses O/W emulsifier to dissolve glabridin powder, the obtained emulsion is viscous and poor in skin feel, and since a large amount of O/W emulsifier is used, skin sensitivity and irritation are caused, so that a better effect can be achieved only in the composition within the scope of the present invention.

Skin feel test

The invention compares the absorption speed, the moisture feeling in the absorption process and the sticky feeling degree of 5s-10s after the absorption.

Test sample: the aqueous composition of glabridin prepared in example 4 of the present invention (glabridin content: 2%)

Comparison sample: an aqueous solution of OLI-2182AW glabridin manufactured by Shanghai Olive industries, inc., which is subjected to envelope treatment with hydroxypropyl cyclodextrin, the glabridin content is 2%.

The testing method comprises the following steps:

30 healthy skin subjects were enrolled, and the same amount of test sample and comparative sample were used at the back of hand, respectively, to sense the absorption rate and freshness of the samples. The subjects scored the test and comparative samples according to their subjective feelings, and given scores of +2, +1, 0, -1, respectively, according to the effect from best to poor. The scores of all subjects were averaged. The test results are shown in Table 1 below:

TABLE 1

Summary of the test: the water-soluble glabridin solution prepared by the commercially available enveloping technology is very sticky after being absorbed although the solution is moist in the smearing process; the aqueous composition of glabridin prepared by the invention has the advantages of faster absorption and good skin feel without stickiness after absorption. The inventors also conducted the same skin feel tests on examples 1-3, 5-6 of the present application, and obtained a use feel similar to example 4.

Industrial applicability

The glabridin aqueous composition and the preparation method thereof can be applied to aqueous cosmetics, have good use sense, simple preparation process and energy consumption saving.

Claims (9)

1. An aqueous glabridin composition comprising: 0.1 to 5.0 weight percent of glabridin powder, 2.0 to 25.0 weight percent of polyalcohol, 15.0 to 50.0 weight percent of amphiphilic humectant, 0 to 5.0 weight percent of O/W emulsifier and the balance of water;

the amphiphilic humectant comprises one or more than two components selected from PEG/PPG-17/6 copolymer, PEG/PPG-18/4 copolymer, PEG/PPG-14/7 dimethyl ether, PEG/PPG-17/4 dimethyl ether, and PEG/PPG/polytetramethylene glycol-8/5/3 glycerin;

the O/W emulsifier comprises one or more than two of PPG-13-decyl tetradecyl polyether-24, PPG-26-butyl alcohol polyether-26, PEG-40 hydrogenated castor oil and PEG-60 hydrogenated castor oil.

2. The composition of claim 1, comprising greater than 0wt% of the O/W emulsifier.

3. The composition of claim 1, comprising 20.0wt% to 50.0wt% of the amphiphilic humectant.

4. A composition according to any one of claims 1 to 3, the polyol comprising a dihydric or more alcohol.

5. The composition of claim 4, wherein the polyol comprises a dihydric or trihydric alcohol having 2 to 10 carbon atoms.

6. The composition of claim 5, wherein the polyol has 2 to 6 carbon atoms.

7. A method of preparing a composition according to any one of claims 1 to 6, comprising the steps of:

(1) Weighing glabridin, polyalcohol, amphiphilic humectant, O/W emulsifier and deionized water according to weight percentage;

(2) Mixing the polyol, amphiphilic humectant and O/W emulsifier;

(3) Adding the glabridin powder into the solution obtained in the step (2), and stirring until the glabridin powder is completely dissolved;

(4) Adding a proper amount of water into the solution obtained in the step (3) to form bicontinuous phase microemulsion;

(5) Adding the remaining water to the solution obtained in (4) to obtain the composition.

8. Cosmetic, characterized in that it comprises a composition according to any one of claims 1 to 6.

9. Use of a composition according to any one of claims 1 to 6 for the preparation of a cosmetic.

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