Micro-capsule with whitening effect in cosmetics and whitening face cream prepared from micro-capsule

Abstract

The invention relates to a micro-capsule with a whitening effect in cosmetics and a whitening face cream prepared from the micro-capsule. The preparation method comprises the following steps: firstly, preparing emulsified liquid by taking Arabic gum, octenyl succinic acid modified starch, sodium hyaluronate and beta-cyclodextrin as raw materials; then, freezing and drying the emulsion to prepare the micro-capsule; and finally, applying the micro-capsule to the face cream. After the face cream is used by people for 8 weeks, the whitening effect of a skin test area is obviously improved, and the skin whiteness value L * and the skin brightness value ITA degree are obviously increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of the preparation of cosmetics, and particularly relates to microcapsules with whitening effects in cosmetics and a whitening cream prepared therefrom. Background Art

[0002] With the rapid development of social economy and the improvement of people's living standards, the public pays more and more attention to appearance, and the improvement of skin color and texture has become the focus of the beauty industry. Under the influence of the traditional aesthetic concept of "one white covers three ugliness", how to improve dull skin color and brighten and whiten facial skin has become a hot topic in the industry.

[0003] In the prior art, kojic acid and arbutin are widely used in the whitening of cosmetics. The application and discovery of kojic acid originated from ancient people's daily work and life. Kojic acid can chelate with the copper cofactor on tyrosinase and reduce the activity of tyrosinase through competitive inhibition. Kojic acid can also block the intermediate products in melanin production and inhibit related proteins (TRP-2), thereby achieving the whitening effect of inhibiting melanin production. Kojic acid has poor stability to light and heat, is easy to oxidize and change color, is easy to chelate with metal ions, and has poor skin absorption effect.

[0004] Arbutin is derived from plants of the Ericaceae family and belongs to a glucosylated hydroquinone derivative. It is reported that it has the effect of reducing the activity of tyrosinase; at the same time, it is reported that arbutin also has the function of inhibiting the maturation of melanosomes in the skin. The results of the research on the whitening mechanism of arbutin show that arbutin can inhibit the formation of melanin by inhibiting the genes related to melanin synthesis. A study found in 2009 that arbutin achieves the whitening effect by reducing the level of α-melanocyte-stimulating hormone (α-MSH) in melanocytes. However, the skin absorption effect of arbutin is not significant and needs to be further improved.

[0005] Aiming at the problem of difficult absorption of kojic acid and arbutin by the skin, the present invention has made a breakthrough in this technical defect. Summary of the Invention

[0006] Aiming at the defects of the prior art, the purpose of the present invention is to provide microcapsules with whitening effects in cosmetics. The wall material of the microcapsules contains a large amount of sodium hyaluronate, and the core material contains kojic acid and arbutin, which have good whitening effects.

[0007] The microcapsules described in the present invention can be prepared by the following method: First, an emulsion is prepared from gum arabic, octenyl succinic anhydride starch ester, sodium hyaluronate and β-cyclodextrin as raw materials; then, the emulsion is freeze-dried to obtain microcapsules.

[0008] Another object of the present invention is to provide a preparation method of the microcapsules with whitening effects in the cosmetics, including the following steps:

[0009] (1) At 50 - 60 °C, kojic acid and arbutin are added to shea butter to obtain a shea butter mixture.

[0010] Preferably, the dosage ratio of kojic acid, arbutin and shea butter is 1 g∶(1 - 2) g∶(20 - 30) g.

[0011] (2) Gum arabic, octenyl succinic anhydride modified starch, sodium hyaluronate and β - cyclodextrin are dissolved in deionized water, stirred and gelatinized in a water bath at 80 - 85 °C for 20 - 40 min. After cooling to 50 - 60 °C, the shea butter mixture prepared in step (1) is added, and homogenized and emulsified at a stirring speed of 7000 - 9000 r / min for 3 - 5 min to obtain an emulsion.

[0012] Preferably, the dosage ratio of gum arabic, octenyl succinic anhydride modified starch, sodium hyaluronate, β - cyclodextrin, shea butter mixture to deionized water is 1 g∶(1 - 2) g∶(1 - 3) g∶(1 - 3) g∶(10 - 12) g∶(150 - 200) mL.

[0013] (3) The emulsion obtained in step (2) is transferred to a petri dish, and the thickness of the emulsion in each dish is 3 - 5 mm. It is pre - cooled in an ultra - low temperature refrigerator for 2 - 3 d, and then frozen in a vacuum freeze - dryer at - 60 - 50 °C and 7.5 - 8.0 mTorr for 8 - 10 h. After freezing, microcapsules are obtained.

[0014] Another object of the present invention is to provide a whitening cream, and the raw material composition of the whitening cream includes the microcapsules with whitening effect in the above - mentioned cosmetics. Among them, the mass ratio of the microcapsules in the whitening cream is 3 - 5%.

[0015] Another object of the present invention is to provide a preparation method of the above - mentioned whitening cream, and the preparation method includes the following steps:

[0016] The first step: 0.98 - 1.02% shea butter, 0.48 - 0.52% cetyl alcohol, 1.98 - 2.02% squalane, 2.95 - 3.05% glycerol caprylate, 0.38 - 0.42% stearic acid and 0.48 - 0.52% glyceryl stearate are uniformly mixed and heated to 85 °C to obtain an oil phase.

[0017] The second step: 0.38 - 0.42% carbomer 980, 0.29 - 0.31% xanthan gum, 1.98 - 2.02% niacinamide, 0.48 - 0.52% sodium hyaluronate, 5.5 - 6.5% butanediol, 4.8 - 5.2% panthenol, 0.48 - 0.52% symextrine, 0.09 - 0.11% disodium EDTA and deionized water are uniformly mixed and heated to 85 °C to obtain an aqueous phase.

[0018] Step 3: Uniformly mix 0.48 - 0.52% sodium benzoate, 0.28 - 0.32% arginine, 0.02 - 0.04% essence, 3 - 5% of the microcapsules of the present invention, and deionized water to obtain the post - added phase.

[0019] Step 4: Slowly pour the oil phase into the water phase, homogenize at 3000 r / min for 6 min, continue stirring at 85°C for 10 min, cool to 41°C, add the post - added phase, homogenize at 5000 r / min for 5 min, evacuate to remove air bubbles, stir and cool to 25°C, then discharge and fill to obtain the whitening cream.

[0020] Note: In the preparation method of the above - mentioned whitening cream, the percentage content before the name of each substance refers to the mass percentage of the substance in the total amount of all preparation raw materials.

[0021] The present invention has the following remarkable advantages:

[0022] (1) According to the whitening mechanism of kojic acid and arbutin, kojic acid and arbutin are complementary in the skin whitening mechanism, thus exerting the maximum whitening effect on the skin.

[0023] (2) Kojic acid and arbutin have good whitening effects on the skin. However, due to their small molecular weights, kojic acid and arbutin are easily absorbed into the human blood and have difficulty binding to the dermal tissue. As a result, the skin absorption amount is small and their maximum efficacy cannot be exerted. The present invention uses kojic acid and arbutin as raw materials to prepare microcapsules. The microcapsules have a relatively large size and can stay well in the dermal tissue area, thus exerting the maximum efficacy of kojic acid and arbutin.

[0024] (3) The wall material of the microcapsules prepared by the present invention contains a large amount of sodium hyaluronate, and the dermal tissue of the human body also contains sodium hyaluronate. Therefore, the microcapsules have better compatibility with the dermal tissue, that is, better binding. After binding, kojic acid and arbutin exert their maximum whitening effect on inhibiting melanin production.

[0025] (4) After the microcapsules prepared by the present invention are added to the whitening cream, after the whitening cream is used by people for 8 weeks, the whitening effect in the skin test area is significantly increased, and the skin whiteness value L* and the skin brightness value ITA° are significantly increased. Among them, the skin whiteness value L* and the skin brightness value ITA° reach above 64.5 and 44.3 respectively.

[0026] (5) Kojic acid and arbutin are easily oxidized when exposed to air. The present invention uses them as the core material and wraps them with the wall material to extend their service life. Detailed implementation mode

[0027] Main source of reagents: Kojic acid and arbutin are purchased from Sinopharm Chemical Reagent Co., Ltd.

[0028] Example 1

[0029] In this embodiment, the microcapsules with whitening effect in cosmetics are prepared by the following method, including the following steps:

[0030] (1) At 55 °C, 1 g of kojic acid and 1.5 g of arbutin are added to 25 g of shea butter to obtain a shea butter mixture.

[0031] (2) 1 g of gum arabic, 1.5 g of octenyl succinic anhydride starch ester, 2 g of sodium hyaluronate and 2 g of β-cyclodextrin are dissolved in 175 mL of deionized water, stirred and gelatinized in a water bath at 83 °C for 30 min. After cooling to 55 °C, 11 g of the shea butter mixture prepared in step (1) is added, and homogenized and emulsified at a stirring speed of 8000 r / min for 4 min to obtain an emulsion.

[0032] (3) The obtained emulsion is transferred to a petri dish, the thickness of the emulsion in each dish is 4 mm, pre-cooled in an ultra-low temperature refrigerator for 2.5 d, and then frozen in a vacuum freeze dryer at -65 °C and 7.6 mTorr for 9 h. After freezing, microcapsules are obtained.

[0033] Example 2

[0034] In this embodiment, the microcapsules with whitening effect in cosmetics are prepared by the following method, including the following steps:

[0035] (1) At 50 °C, 1 g of kojic acid and 1 g of arbutin are added to 20 g of shea butter to obtain a shea butter mixture.

[0036] (2) 1 g of gum arabic, 1 g of octenyl succinic anhydride starch ester, 1 g of sodium hyaluronate and 1 g of β-cyclodextrin are dissolved in 150 mL of deionized water, stirred and gelatinized in a water bath at 80 °C for 20 min. After cooling to 50 °C, 10 g of the shea butter mixture prepared in step (1) is added, and homogenized and emulsified at a stirring speed of 7000 r / min for 3 min to obtain an emulsion.

[0037] (3) The obtained emulsion is transferred to a petri dish, the thickness of the emulsion in each dish is 3 mm, pre-cooled in an ultra-low temperature refrigerator for 2 d, and then frozen in a vacuum freeze dryer at -60 °C and 7.5 mTorr for 8 h. After freezing, microcapsules are obtained.

[0038] Example 3

[0039] In this embodiment, the microcapsules with whitening effect in cosmetics are prepared by the following method, including the following steps:

[0040] (1) At 60 °C, 1 g of kojic acid and 2 g of arbutin are added to 30 g of shea butter to obtain a shea butter mixture.

[0041] (2) Dissolve 1 g of gum arabic, 2 g of octenyl succinic anhydride starch ester, 3 g of sodium hyaluronate, and 3 g of β-cyclodextrin in 200 mL of deionized water, stir and gelatinize in a water bath at 85 °C for 40 min. After cooling to 60 °C, add 12 g of the shea butter mixture prepared in step (1), and homogenize and emulsify at a stirring speed of 9000 r / min for 5 min to obtain an emulsion.

[0042] (3) Transfer the obtained emulsion to a petri dish, with the thickness of the emulsion in each dish being 5 mm. Place it in a ultra-low temperature refrigerator and pre-cool for 3 d, then freeze in a vacuum freeze dryer at -50 °C and 8.0 mTorr for 10 h. After freezing, microcapsules are obtained.

[0043] Comparative Example A

[0044] Taking Example 1 as a comparison, in this Comparative Example A, kojic acid is not added, and "add 1 g of kojic acid and 1.5 g of arbutin to 25 g of shea butter at 55 °C" in step (1) is adjusted to "add 1.5 g of arbutin to 25 g of shea butter at 55 °C", and other preparation methods are implemented according to the preparation method of Example 1.

[0045] Comparative Example B

[0046] Taking Example 1 as a comparison, in this Comparative Example B, arbutin is not added, and "add 1 g of kojic acid and 1.5 g of arbutin to 25 g of shea butter at 55 °C" in step (1) is adjusted to "add 1 g of kojic acid to 25 g of shea butter at 55 °C", and other preparation methods are implemented according to the preparation method of Example 1.

[0047] Comparative Example C

[0048] Taking Example 1 as a comparison, in this Comparative Example C, the dosages of kojic acid and arbutin are reduced, and "add 11 g of the shea butter mixture prepared in step (1)" in step (2) is adjusted to "add 1.1 g of the shea butter mixture prepared in step (1)", and other preparation methods are implemented according to the preparation method of Example 1.

[0049] Comparative Example D

[0050] Taking Example 1 as a comparison, in this Comparative Example D, the same amounts of kojic acid and arbutin in Example 1 are directly mixed to obtain a mixture, which is used in Comparative Example D for application.

[0051] Application Examples and Performance Evaluation:

[0052] (1) Preparation of Whitening Cream

[0053] The microcapsules prepared in Examples 1 to 3 and Comparative Examples A to C and the mixture prepared in Comparative Example D were applied to a whitening cream, and the prepared whitening creams were labeled as Applied Example 1, Applied Example 2, Applied Example 3, Applied Comparative Example A, Applied Comparative Example B, Applied Comparative Example C, and Applied Comparative Example D, respectively.

[0054] The contents (percentages, %) of the components in the whitening creams of Applied Examples 1 to 3 and Applied Comparative Examples A to D are shown in Table 1 below, and the whitening creams were prepared according to the following steps:

[0055] First step: Shea butter, cetyl alcohol, squalane, glyceryl caprylate, stearic acid, and glyceryl stearate were uniformly mixed and heated to 85 °C to obtain an oil phase.

[0056] Second step: Carbomer 980, xanthan gum, niacinamide, sodium hyaluronate, butanediol, panthenol, symex, disodium EDTA, and water were uniformly mixed and heated to 85 °C to obtain an aqueous phase.

[0057] Third step: Sodium benzoate, arginine, fragrance, the microcapsules prepared in the present invention or kojic acid and arbutin, and deionized water were uniformly mixed to obtain a post-addition phase.

[0058] Fourth step: The oil phase was slowly poured into the aqueous phase, homogenized at 3000 r / min for 6 min, continuously stirred at 85 °C for 10 min, cooled to 41 °C, the post-addition phase was added, homogenized at 5000 r / min for 5 min, degassed under vacuum, and stirred and cooled to 25 °C, then it was ready for discharging and filling.

[0059] Table 1 Formulation of the microcapsules prepared in Examples 1 to 3 and Comparative Examples A to D applied to the whitening cream (by mass percentage, %)

[0060]

[0061] Note 1 : The corresponding microcapsules: refer to the microcapsules prepared in Examples 1 to 3 and Comparative Examples A to C. For example, the microcapsules prepared in Example 1 were applied to Applied Example 1, and so on.

[0062] Note 2 : The dosages of kojic acid and arbutin are the same as those in Applied Example 1.

[0063] (2) Evaluation of the whitening effect of the whitening cream:

[0064] (a) Test indexes

[0065] Skin whiteness (brightness) L* value: The L* value is for white balance. The larger the value, the more the color tends to white, and vice versa, it tends to black.

[0066] Skin brightness (sallow degree) ITA° value: The ITA° value is the Individual Typological Angle (ITA°). The larger the ITA° value, the brighter the skin. Conversely, the darker and sallower the skin.

[0067] (b) Subject screening

[0068] Thirty subjects were selected, including women aged 20 - 45 years old; indoor workers; in line with the Helsinki Declaration; the inclusion and exclusion criteria of the subjects met the inclusion and exclusion criteria of the "Diagnostic Criteria and Treatment Principles for Cosmetic Contact Dermatitis"; no severe systemic diseases, no immunodeficiency or autoimmune diseases; no active allergic diseases; no history of allergy to skin care cosmetics; no systemic use of hormonal drugs and immunosuppressants within 1 month, not pregnant or lactating; no ethical taboos; according to the Chardon grouping method, the skin color was between II - IV.

[0069] The evaluation results of the efficacy of whitening cosmetics will be affected by factors such as the degree of sun exposure of the subjects. Therefore, subjects engaged in outdoor work and those with outdoor activity plans during the experiment should be avoided to minimize the influence of external factors on the experimental results. The skin background value should be collected at each test to record the skin color change of the subjects.

[0070] (c) Test method

[0071] The washout period was at least 1 week. The inner sides of the flexor arms of the left and right arms of the subjects were selected as the test areas, randomly marked, and a blank area (without using any samples) was set. Samples 1, 2, and 3 were applied to the test areas, once in the morning and once in the evening every day (the dosage was 2 mg / cm 2 ), and the usage period was 8 weeks. During the test, the subjects did not change the brand and habit of the facial cleanser they usually used. Data collection was carried out before using the samples and 8 weeks after using the samples. The skin background value was collected for both tests. Ensure that the test time used in each data collection process was unified, the test environment had a constant temperature of (22 ± 1) °C and a humidity of 50% ± 5%. After the subjects cleaned the test area with clean water before the test, they sat quietly in this environment for 20 minutes.

[0072] These subjects were randomly divided into seven groups, numbered as Group A of subjects, Group B of subjects, Group C of subjects, Group D of subjects, Group E of subjects, Group F of subjects and Group G of subjects. Each group used the whitening cream prepared by the corresponding numbered Application Example 1, Application Example 2, Application Example 3, Application Comparative Example A, Application Comparative Example B, Application Comparative Example C and Application Comparative Example D (for example, Group A of subjects used the whitening cream prepared by Application Example 1, and so on). Each group of subjects used the same sample. The experimental period was 8 weeks. After 8 weeks, the whitening degree of the test area of the subjects was observed, and then the whitening degree of the test area was quantitatively analyzed using a VISIA digital skin analyzer, and the analysis results were statistically calculated. The test results are shown in the following table.

[0073] Table 2 Results of Seven Groups of Subjects after Using the Whitening Cream

[0074] Project Skin whiteness value L* Skin brightness value ITA° Subject group A 64.8 44.3 Subject group B 64.5 44.7 Subject group C 65.2 44.6 Subject group D 62.7 41.8 Subject group E 62.6 41.7 Subject group F 60.4 40.3 Subject group G 60.8 40.5

[0075] As can be seen from Table 2, after the microcapsules prepared by the present invention were added to the whitening cream and the whitening cream was used by people for 8 weeks, the skin whiteness value L* and the skin brightness value ITA° increased significantly. Among them, the skin whiteness value L* and the skin brightness value ITA° reached above 64.5 and 44.3 respectively.

[0076] As can be seen from Table 2, the skin whiteness value L* and the skin brightness value ITA° of Group A - C of subjects were significantly higher than those of Group D - G of subjects, which indicates that: the simultaneous addition of kojic acid and arbutin, an appropriate amount of kojic acid and arbutin, and the use in the form of microcapsules all have important effects on the whitening efficacy of the whitening cream.

Claims

1. A method for preparing microcapsules with whitening effect in cosmetics, characterized in that: The preparation method comprises the following steps: (1) adding kojic acid and arbutin to shea butter at 50-60° C. to obtain a shea butter mixed solution; (2) dissolving gum arabic, octenyl succinate starch, sodium hyaluronate and β-cyclodextrin in deionized water, stirring and gelatinizing in a water bath at 80-85° C. for 20-40 min, cooling to 50-60° C., adding the shea butter mixture obtained in step (1), and homogenizing and emulsifying at a stirring speed of 7000-9000 r / min for 3-5 min to obtain an emulsion; (3) The emulsion obtained in step (2) is transferred to a culture dish, wherein the thickness of the emulsion in each dish is 3 to 5 mm, and is placed in an ultra-low temperature refrigerator for precooling for 2 to 3 days, and then frozen in a vacuum freeze dryer at -60 to -50°C and 7.5 to 8.0 mTorr for 8 to 10 hours. After the freezing is completed, microcapsules are obtained.

2. The method for preparing microcapsules with whitening effect in cosmetics according to claim 1, characterized in that: The usage ratio of kojic acid, arbutin and shea butter in step (1) is 1g: (1-2)g: (20-30)g.

3. The method for preparing microcapsules with whitening effect in cosmetics according to claim 1, characterized in that: The dosage ratio of the mixed solution of gum arabic, octenyl succinate starch, sodium hyaluronate, β-cyclodextrin, shea butter and deionized water in step (2) is 1g: (1-2)g: (1-3)g: (1-3)g: (10-12)g: (150-200)mL.

4. A microcapsule with whitening effect in cosmetics, characterized in that: The invention is prepared by the method according to any one of claims 1 to 3.

5. A whitening face cream, wherein the raw material composition of the whitening face cream includes the microcapsules with whitening effect in any one of the cosmetics of claims 1 to 4, wherein: The mass ratio of the microcapsules to the whitening cream is 3-5%.

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