CN110731925A

CN110731925A - Whitening cosmetic composition

Info

Publication number: CN110731925A
Application number: CN201910694297.9A
Authority: CN
Inventors: 王莎莎; 张正方
Original assignee: Zhejiang Yangshengtang Institute of Natural Medication Co Ltd
Current assignee: Natural Medicine Institute of Zhejiang Yangshengtang Co Ltd; Zhejiang Yangshengtang Institute of Natural Medication Co Ltd
Priority date: 2019-07-30
Filing date: 2019-07-30
Publication date: 2020-01-31
Also published as: WO2021017877A1

Abstract

The present invention relates to the use of concentrated birch juice in whitening cosmetic compositions, and whitening cosmetic compositions comprising concentrated birch juice.

Description

Whitening cosmetic composition

Technical Field

Background

Birch is a deciduous tree of the betulinaceae family, and currently, there are about 100 varieties worldwide, mainly distributed in the northern temperate zone and the cold temperate zone. Wherein, there are about 29 varieties in China, and the varieties are mainly distributed in the northeast, northwest and southwest. Birch trees are mostly grown in remote mountainous areas with less human intervention and no industrial pollution. Birch sap (also called birch sap) is fresh sap obtained by cutting bark or drilling trunk of birch, and is colorless or yellowish, has no precipitate or impurity, and has light birch fragrance. The birch juice contains abundant saccharide, amino acids, vitamins, biotin, cytokinin, trace mineral elements, aromatic oil, betulin, saponin, etc., and has good skin care effects of keeping moisture, resisting inflammation, removing wrinkle, whitening, etc.

Disclosure of Invention

the present invention provides concentrated birch juices, at a concentration of about 1.05-8 times, preferably about 1.1-4 times, more preferably about 1.2-2 times.

in another aspect, the present invention relates to the use of concentrated birch sap in whitening cosmetic compositions, wherein the concentrated birch sap is concentrated from about 1.05 to about 8 times, preferably from about 1.1 to about 4 times, more preferably from about 1.2 to about 2 times, said concentrated birch sap has good whitening and spot-removing effects, inhibits the production and transport of melanin, reduces skin dullness, and makes the skin more fair and bright.

Birch juices contemplated in the present invention are derived from Betula genus of betulinaceae family, and may be derived from four varieties of white birch (Betula alba), Betula luminifera (Betula pubescens), Betula Pendula (Betula Pendula) and Betula asiatica (Betula platyphylla). The birch juice is colorless, transparent, precipitate-free and impurity-free juice which is obtained by manually drilling and collecting at the base of a trunk of the birch between thawing and early spring leaf emergence and has birch faint scent and rich nutrition. The birch juice is commercially available and used as such, for example from greater Khingan over wild berry development, LLC.

The concentrated birch sap of the present invention is obtained by concentrating the above-mentioned commercially available products. Concentration methods are known in the art, such as heat concentration, low temperature vacuum concentration, membrane concentration, and the like. In the present invention, the concentration is preferably performed by a low-temperature freeze concentration or membrane concentration process, for example, commercially available birch juice stock solution is fed into a low-temperature drying device, cooled to-40 ℃ to-70 ℃, and vacuumized to 0.1 to 30Pa to perform low-temperature vacuum concentration, so as to obtain concentrated birch juice with different concentration times.

Unexpectedly, the inventors found that concentrated birch sap had significantly better whitening efficacy as compared to the unconcentrated birch sap stock solution, as demonstrated by inhibiting the synthesis and activity of tyrosinase, inhibiting the synthesis and transport of melanin, reducing dark skin tone, and making the skin whiter and brighter.

, the inventor has also found that the whitening efficacy of concentrated birch juice is not simply linear with its concentration, but rather it shows a tendency to increase and then decrease as the concentration factor increases, therefore, it is critical to control the concentration factor of birch juice, which in the present invention is about 1.05-8 times, preferably about 1.1-4 times, and more preferably about 1.1-2 times.

In another aspect, the present invention relates to whitening cosmetic compositions comprising (a) the concentrated birch juice, wherein the concentration of the concentrated birch juice is about 1.05-8 times, preferably about 1.1-4 times, more preferably about 1.2-2 times.

In a preferred embodiment, the whitening cosmetic composition of the present invention does not contain a chelating agent such as EDTA salt, sodium polyphosphate, sodium metaphosphate, gluconic acid, and the like.

In a preferred embodiment, the whitening cosmetic composition of the present invention does not include any added water, but does not exclude moisture inherently included in the respective components.

The concentrated birch juice is present in the whitening cosmetic composition in an amount of about 18-98% by weight, preferably 20-95% by weight, more preferably 22-90% by weight, most preferably 30-90% by weight, based on the total weight of the whitening cosmetic composition.

In addition to the (a) concentrated birch juice, the whitening cosmetic composition optionally comprises (B) ingredients commonly used in skin care cosmetics, including vehicles, active ingredients, adjuvants, and the like. Component (B) is known in the art and can be selected by those skilled in the art as desired, for example, in an amount of about 2 to 82% by weight, based on the total weight of the cosmetic composition.

The vehicle includes, for example, diluents, dispersants or carriers and the like, examples of which include, but are not limited to, ethanol, dipropylene glycol, butylene glycol, and the like. The amount of said vehicle in said cosmetic composition is known in the art, and is for example generally comprised between 0.5 and 20% of the total weight of component (B).

Such active ingredients include, for example, emollients, humectants, whitening actives and the like.

Examples of such emollients include, but are not limited to, olive oil, macadamia nut oil, sweet almond oil, grape seed oil, avocado oil, corn oil, sesame oil, soybean oil, peanut oil, meadowfoam seed oil, safflower seed oil, rosa canina oil, argan oil, jojoba seed oil, sunflower seed oil, palm kernel oil, squalane, ethylhexyl palmitate, isopropyl myristate, hydrogenated polyisobutene, isohexadecane, isododecane, diethylhexyl carbonate, dioctyl carbonate, isopropyl lauroyl sarcosinate, isononyl isononanoate, hydrogenated polydecene, tris (ethylhexanoate), cetyl ethylhexanoate, bis-diethoxydiol cyclohexane 1, 4-dicarboxylate, caprylic/capric triglyceride, oleyl erucate myristate, octyldodecanol, dimethicone, octylmethicone, cetyl dimethicone, cyclopentadecyl dimethicone, and the like, examples of solid emollients include, but are not limited to, stearyl alcohol, cetyl stearyl alcohol, shark alcohol, behenyl wax, and the like, these waxes are commonly known in the art, such compositions of these waxes are included in the amounts of these waxes are 50% by weight of these waxes, such as the cosmetic compositions.

Examples of such moisturizers include, but are not limited to, or more of glycerin, diglycerin, butylene glycol, propylene glycol, 1, 3-propanediol, dipropylene glycol, 1, 2-pentanediol, polyethylene glycol-8, polyethylene glycol-32, methyl gluceth-10, methyl gluceth-20, PEG/PPG-17/6 copolymer, glyceryl polyether-7, glyceryl polyether-26, glyceryl glucoside, PPG-10 methyl glucose ether, PPG-20 methyl glucose ether, PEG/PPG/polytetramethylene glycol-8/5/3 glycerin, sucrose, trehalose, rhamnose, mannose, raffinose, betaine, erythritol, xylitol, urea, glyceryl polyether-5 lactate, sodium hyaluronate, hydrolyzed sodium hyaluronate, acetylated sodium hyaluronate, sodium polyglutamate, hydrolyzed sclerotium rolum, pullulan, tremella polysaccharides, tamarind seed polysaccharides, and the like.

The whitening active ingredients, including but not limited to, kojic acid, ascorbyl glucoside, arbutin, tranexamic acid, niacinamide, phytosterols/behenyl alcohol/octyldecanol lauroyl glutamate, phenethyl resorcinol, turmeric root extract, birch bark extract, ceramide 2, ceramide 3, acetyl phytosphingosine, resveratrol, palmetto bark extract, coleus forskohlii root extract, pepper seed extract, ubiquinone, cholesterol stearate, ascorbic acid, ascorbyl dipalmitate, tocopherol (vitamin E), tocopheryl acetate, bisabolol, ascorbyl tetraisopalmitate, pyridoxine dicaprylate, pyridoxine dipalmitate, retinol palmitate, phytosterols/octyldodecanoyl laurate glutamate, bis-behenyl alcohol/isostearyl alcohol/phytosterol dimer linoleate, phytosteryl macadamia oleate, various plant extracts, or more of the whitening active ingredients in the composition are generally present in the art at a weight level of 0.01, and a weight percentage of the composition is generally present invention.

Such adjuvants include, for example, emulsifiers, thickeners, preservatives, fragrances and the like.

Examples of such emulsifiers include, but are not limited to, cetearyl olivate, sorbitan olivate, polysorbate-60, polysorbate-80, methylgluco-sesquistearate, PEG-20 methylgluco-sesquistearate, PEG-40 hydrogenated castor oil, PPG-26-butanoeth-26, PEG-4 polyglyceryl-2 stearate, PEG-60 hydrogenated castor oil, steareth-2, steareth-21, PPG-13-decyltetraeth-24, cetearyl glucoside, PEG-100 stearate, glyceryl stearate SE, coco glucoside, ceteareth-25, PEG-40 stearate, polyglyceryl-3 methylgluco distearate, glyceryl stearate citrate, polyglyceryl-10 stearate, polyglyceryl-10 myristate, polyglyceryl-10 dioleate, polyglyceryl-10 laurate, polyglyceryl-10 isostearate, polyglyceryl-10 oleate, polyglyceryl-10 diisostearate, polyglyceryl-6 laurate, polyglyceryl-6 myristate, sucrose % of the total weight of such emulsifiers, e.g. the emulsifier is generally known in the art, and the amount of such emulsifiers are 0.5% by weight of the cosmetic composition.

Examples of the thickener include, but are not limited to, kinds or more of high molecular polymers such as carbomers, acrylates and derivatives thereof, xanthan gum, arabic gum, polyethylene glycol-14M, polyethylene glycol-90M, succinoglycan, hydroxyethyl cellulose, hydroxypropyl methyl cellulose, etc. the content of the thickener in the cosmetic composition is known in the art, and for example, it is usually 0.1 to 10% by weight based on the total weight of the component (B).

Examples of such preservatives include, but are not limited to, or more of methylparaben, propylparaben, phenoxyethanol, benzyl alcohol, phenylethyl alcohol, bis (hydroxymethyl) imidazolidinyl urea, potassium sorbate, sodium benzoate, chlorphenesin, sodium dehydroacetate, caprylhydroxamic acid, 1, 2-hexanediol, 1, 2-pentanediol, p-hydroxyacetophenone, capryl glycol, caprylic glyceride, glyceryl deca carbonate, sorbitan caprylate, ethylhexylglycerin, moutan root extract, and the like, the content of such preservatives in the cosmetic composition is known in the art, for example, it is typically 0.01 to 2% by weight of the total component (B).

The whitening cosmetic composition of the present invention may be prepared by any suitable method known in the art. For example, it is prepared using a dissolving tank, an emulsifying pot, a disperser, a transfer pump, etc., which are commonly used in the cosmetic field. The preparation method comprises putting water soluble substance into water phase dissolving kettle, putting oil soluble substance into oil phase dissolving kettle, heating the two kettles to about 80 deg.C, wherein the raw material easy to agglomerate can be pre-dispersed with disperser. After the dissolution is finished, the oil phase and the water phase are conveyed into an emulsifying pot, and homogenized and emulsified for about 5-15 minutes. After emulsification is finished, the temperature of the material body is reduced to normal temperature, optional essence, preservative and the like are added, and the pH of the product is adjusted according to needs. After the relevant detection indexes are qualified, the products can be filled and delivered. The preparation method can be deleted or adjusted according to the requirements of the preparation formulation, and can be used for preparing the preparation formulations such as cream, milky lotion, essence and the like according to the requirements.

Examples

The invention is described in further detail at with reference to the following examples, however, it should be understood that these examples and comparative examples are intended only to illustrate the invention in more detail and should not be construed as limiting in any way the scope of the appended claims.

Example 1: influence of stock solution and concentrated birch juice on melanin synthesis and transport related gene expression

In this example, the effect of birch sap stock solution and concentrated birch sap at different concentration factors on melanin synthesis, transport-related gene expression was tested and compared.

1. Concentration of birch sap

Fresh birch juice stock solution purchased from Daxingan Ling surpassing the company Limited for wild berry development is input into a low-temperature drying device, cooled to-65 ℃, vacuumized to 0.1Pa, and concentrated to 1.05 times, 1.1 times, 1.2 times, 1.5 times, 2 times, 4 times and 8 times respectively.

2. Testing

An experimental instrument: a fluorescent quantitative PCR instrument (Roche), a super clean bench (Sujing), a carbon dioxide incubator (Binder), a microplate reader (BIO-TEK) and a micro oscillator.

Experimental reagents and consumables: human primary melanocytes, 6-well plates, melanocyte culture solution, RNA extraction kit, reverse transcription kit, Trizol lysate and the like.

Melanocyte-based gene expression analysis procedures were as follows:

(1) inoculation: cells were seeded into 6-well plates at a seeding density of 5E 5/well at 37 ℃ and 5% CO₂Incubating in an incubator overnight;

(2) administration: when the cell plating rate in the 6-hole plate reaches about 60%, adding the test substances of each group, and arranging 6 multiple holes in each group;

(3) collecting a sample: at 37 ℃ and 5% CO₂After 24 hours in the incubator, discarding the culture solution, adding 1mL Trizol into each hole, blowing and beating the lysed cells, and collecting the samples;

(4) and (3) PCR detection: extracting RNA, carrying out reverse transcription to cDNA, and carrying out fluorescent quantitative PCR detection;

(5) and (3) analysis: by using 2^-△△CTThe method carries out result calculation and adopts a T-Test method for statistical analysis.

The test results are shown in the following table:

note: indicates significant in comparison to the original juice, P value less than 0.05; indicated as very significant compared to the raw juice, P values were less than 0.01.

The results show that the birch juice with the concentration multiple of 1.1-4 times obviously inhibits the expression of genes related to the synthesis and transportation of melanin compared with the birch juice raw juice, and particularly, when the concentration multiple is 1.1-2 times, the expression levels of the genes related to the synthesis of melanin, TYR1, TYR2, PMEL 17, MIFT M and MIFT B as well as the genes related to the transportation of melanin, Rab-27a and Myosin va are all obviously lower than the expression levels of the birch juice raw juice.

Example 2: effect of stock solution and concentrated birch juice on melanin synthesis and transport related protein expression

In this example, the effect of birch sap stock and birch sap at different fold concentrations on protein expression associated with melanin synthesis and transport was tested and compared.

1. Concentration of birch sap

2. Testing

An experimental instrument: super clean bench (Sujing), plate washing machine (BIO-RAD), enzyme labeling instrument (BIO-TEK), carbon dioxide incubator (Binder)

Experimental reagents and consumables: human primary melanocytes, 12-hole plates, melanocyte culture solution, ELISA detection kits with different indexes and the like.

The test procedure was as follows:

(1) inoculating at the inoculation density of 2E 5/well in 12-well culture plate, culturing at 37 deg.C in 5% CO2 incubator, and changing culture medium every two days for times;

(2) administration: when the cell fusion reaches more than 60 percent again, adding the test substances of different groups, and arranging 6 compound holes in each group;

(3) collecting a sample: at 37 ℃ and 5% CO₂After 48 hours in the incubator, discarding the culture solution, adding 1mL Trizol into each hole, blowing and beating the lysed cells, and collecting the samples;

(4) and (3) detection: performing index measurement according to a measurement method of the ELISA kit;

(5) and (3) analysis: and carrying out statistical analysis by adopting a T-Test method.

The test results are shown in the following table.

The results show that the birch juice with the concentration multiple of 1.1-4 times can obviously inhibit the expression of the melanin synthesis and transportation related proteins compared with the birch juice raw juice, and especially when the concentration multiple is 1.1-2 times, the expression levels of the melanin synthesis related proteins TYR, TYR1, TYR2, PMEL 17, MIFT M and MIFT B and the melanin transportation related proteins Rab-27a and Myosin va are all obviously lower than that of the birch juice raw juice.

Example 3: effect of stock birch juice and concentrated birch juice on melanogenesis in melanocytes

In this example, the effect of birch juice stock and birch juice at different concentration factors on melanin production in melanocytes was tested and compared.

1. Concentration of birch sap

2. Testing

An experimental instrument: clean bench (Sujing), carbon dioxide incubator (Binder), water bath, enzyme labeling instrument (BIO-TEK).

Experimental reagents and consumables: human primary melanocytes, 12-well plates, melanocyte culture solution and NaOH lysate.

The experimental method comprises the following steps:

(1) inoculation, inoculating the strain into a 12-hole culture plate at the inoculation density of 2E 5/hole, culturing at 37 ℃ in a 5% CO2 incubator, and changing the culture medium for times every two days.

(2) Administration: when the cell fusion reaches more than 60% again, adding the test substances of different groups, and simultaneously setting a negative control group (without adding drugs) and setting 6 multiple holes in each group.

(3) Collecting a sample: after culturing in a 5% CO2 incubator at 37 ℃ for 48 hours, the culture medium was discarded, washed 3 times with PBS, and then 100ul of 1mol/L NaOH was added thereto, and the mixture was subjected to 80 ℃ water bath for 1 hour.

(4) And (3) detection: after completion of the water bath, centrifugation was carried out at 10000rpm for 10 minutes, and the supernatant was aspirated and the absorbance (A) was measured at 460nm with a microplate reader, and the melanin inhibition was calculated according to the following formula: melanin inhibition (%) was 100% (a negative control group-a administration group)/a negative control group%

(5) And (3) analysis: statistical analysis was performed using the T-Test method.

The test results are shown in the following table.

The above test results show that the birch juice concentrated by 1.1-4 times can significantly inhibit the production of melanin in melanocytes, compared with the birch juice stock solution.

Example 4: effect of birch sap stock solution and concentrated birch sap on melanogenesis in 3D melanocyte models

In this example, the effect of birch juice stock and birch juice at different concentration folds on melanin production in a 3D melanocyte model was tested and compared.

1. Concentration of birch sap

Fresh birch juice stock solution purchased from Daxingan mountain surpassing the company Limited for wild berry development is input into a reverse osmosis circulating device, the operating pressure is controlled at 0.5-5bar, the operating temperature is controlled at 20-35 ℃, and the circulation is carried out until the birch juice is respectively concentrated to 1.1 times, 1.2 times, 1.5 times, 2 times and 4 times.

2. Test method

An experimental instrument: clean bench (Sujing), carbon dioxide incubator (Binder), UVB irradiator, water bath, enzyme labeling instrument (BIO-TEK).

Experimental reagents and consumables: 3D melanoderm model (self-made in laboratory), model culture solution, NaOH lysate.

The experimental method comprises the following steps:

(1)3D model construction: the 3D skin model was constructed using keratinocytes and melanocytes.

(2) Model making and administration, namely carrying out UVB irradiation treatment (UVB: 50mJ/cm2) every day when the model leaves a factory, namely 0 day, then respectively coating quantitative samples on the surfaces of the corresponding models, coating model culture solution only on a model control group, coating 6 multiple holes in each group, coating times every day, and prolonging the total action time for 4 days.

(3) Collecting and detecting: after the action of the sample is finished, taking out the model, washing the model for 3 times by PBS, placing the model in a centrifuge tube, adding 100ul NaOH with the concentration of 1mol/L, carrying out water bath at 80 ℃ for 1 hour, centrifuging the model for 10 minutes under the condition of 10000rpm after the water bath is finished, sucking the supernatant, measuring the light absorption value (A) by an enzyme-labeling instrument at 460nm, and calculating the melanin inhibition rate according to the following formula:

melanin inhibition (%) was 100% (model a control group-a administration group)/model a control group%

(4) And (3) analysis: statistical analysis was performed using the T-Test method.

The test results are shown in the following table.

The above test results show that, compared with the birch juice stock solution, the birch juice concentrated by 1.1-4 times can significantly inhibit the generation of melanin in a 3D melanin skin model.

Example 5: preparation of whitening essence emulsion composition

The formula of the whitening essence emulsion composition is shown in the following table:

phase (C)	Composition (I)	S	S1
				A	Concentrated birch juice 1.2 times	0	68.17
	Water (W)	68.17	0
					Hyaluronic acid sodium salt	0.03	0.03
	Xanthan gum	0.1	0.1
					Allantoin	0.1	0.1
	Hydroxy phenyl methyl ester	0.2	0.2
					PEG-11 methyl Ether Dimethicone	0.1	0.1
	Panthenol	0.3	0.3
					Cetearyl olive oleate and sorbitan olive oleate	1	1
	Glycerol	4	4
					Butanediol	5	5
	(ester) acrylic acid/vinyl isodecanoate crosspolymer	0.3	0.3
				B	Batyl alcohol	0.3	0.3
	Phytosterol/octyldodecanol lauroyl glutamate	0.3	0.3
					Tocopherol (vitamin E)	0.2	0.2
	Glycerol tri (ethylhexanoate) ester	3	3
				C	Polymethylsilsesquioxane	0.5	0.5
	Polydimethylsiloxane	1	1
				D	Tromethamine	0.4	0.4
E	Ascorbic acid	2	2
					Concentrated birch juice 1.2 times	0	13
	Water (W)	13	0

The whitening essence composition is prepared as follows:

respectively heating phases 1 and A, B to 80 ℃ to be dissolved uniformly;

2. keeping the temperature at 80 ℃, slowly adding the phase B into the phase A under stirring, stirring for 10 minutes, and homogenizing at 10000 RPM/minute for 5 minutes;

3. slowly stirring and cooling to 60 ℃ after defoaming, adding the pre-dispersed phase C into the phase AB, and homogenizing for 3 minutes at 10000 RPM/minute;

4. adding the phase D into the phase ABC, and cooling to 50 ℃ under stirring;

5. and adding the E phase which is uniformly mixed in advance into the ABCD phase, uniformly stirring, cooling to 40 ℃, and discharging.

Using the half-face control test method, 20 volunteers were tested before and 8 weeks after using the product as follows:

1) measuring L of facial skin using a Colorimeter instrument;

2) the changes of melanin and haematochrome of the skin at the same position were measured using a Maxmeter MX18 reflectance spectrometer.

3) The facial patterns of the subjects were collected by VISIA-CR under different light sources at different times and the skin gloss, whiteness L and visible spot area of the subject's face were analyzed by IPP software at different test time points and measurement areas.

The result shows that compared with the whitening essence composition S, the whitening essence composition S1 can improve the facial skin brightness L value by 3.54 percent, reduce the melanin content by 15.86 percent, reduce the heme content by 19.8 percent and improve the skin brightness by 18.53 percent after being used for 8 weeks.

Example 6: preparation of whitening cream composition

The formula of the whitening cream composition is shown in the following table:

the whitening cream composition is prepared as follows:

respectively heating phases 1 and A, B to 80 ℃ to be dissolved uniformly;

3. slowly stirring and cooling to 60 ℃ after defoaming, adding the phase C into the phase AB, and homogenizing for 3 minutes at 10000 PM/min;

4. cooling to 50 ℃ under stirring, adding the components of the phase D except the potassium hydroxide into the phase ABC, uniformly stirring, and adjusting the pH value of the system to 6.5-6.8 by using the potassium hydroxide;

5. adding the phase E into the paste, stirring and cooling to 40 ℃ to discharge.

After 20 subjects used the above-described formula for 4 weeks, the use was subjectively evaluated. The result shows that 18 people have obviously improved dark skin color, and the overall brightness and the white skin degree of the skin are obviously improved. 16 of them reflect that the local plaque is obviously lightened and the skin color becomes more uniform.

Example 7: whitening emulsion composition

The formula of the whitening emulsion composition is shown in the following table:

the skin care emulsion composition is prepared as follows:

respectively heating phases 1 and A, B to 80 ℃ to be dissolved uniformly;

3. slowly stirring and cooling to 60 ℃ after defoaming, and adding the phase C into the phase AB;

4. cooling to 50 ℃ under stirring, adding the pre-mixed uniformly-mixed phase D into the phase ABC, and uniformly stirring;

The technical solutions of the above-described embodiments are preferred embodiments of the present invention, and several modifications and changes can be made without departing from the principle of the present invention, and these modifications and changes should also be considered as being within the protection scope of the present invention.

Claims

concentrated birch juice with concentration ratio of 1.05-8 times, preferably 1.1-4 times, more preferably 1.2-2 times.
2. Use of concentrated birch sap in a whitening cosmetic composition, wherein the concentrated birch sap is concentrated 1.05-8 times, preferably 1.1-4 times, more preferably 1.2-2 times.
A whitening cosmetic composition comprising (A) concentrated birch sap, wherein the concentrated birch sap is concentrated 1.05-8 times, preferably 1.1-4 times, more preferably 1.2-2 times.
4. The whitening cosmetic composition of claim 3, comprising 18 to 98% by weight, preferably 20 to 95% by weight, more preferably 22 to 90% by weight, most preferably 30 to 90% by weight of the concentrated birch juice, based on the total weight of the whitening cosmetic composition.
5. The whitening cosmetic composition of claim 3 or 4, wherein the composition does not include any added water.
6. The whitening cosmetic composition of any of claims 3-5, wherein the composition further comprises (B) ingredients commonly used in skin care cosmetics.