Soap-based whitening facial cleanser and preparation method thereof

Abstract

The invention relates to the technical field of A61K8 / 00, in particular to a soap-based whitening facial cleanser and a preparation method thereof.The soap-based whitening facial cleanser is at least prepared from, by mass, 20%-35% of natural grease soap liquid, 15%-50% of amino acid surfactant, 10%-25% of zwitterionic surfactant, 0.1%-2% of cationic high-molecular polymer and 1%-10% of thickener, by optimizing a formula system of the facial cleanser, the pH value of the provided facial cleanser is stabilized to be 8.0 or below, the problems that the functional substances of the whitening facial cleanser are inactivated and degraded due to the fact that the pH value of a soap base system is high are solved, and the actual application requirements are better met.

Description

Technical Field

[0001] The invention relates to the technical field of A61K8 / 00, in particular to a soap-based whitening cleanser and a preparation method thereof. Background Art

[0002] At present, the basic framework of whitening cleansers on the market mainly includes three categories: soap system, amino acid system and surfactant system. Most whitening agents are mainly niacinamide, supplemented by ursolic acid, glabridin, 377, VCIP, etc., to form a complete whitening cleanser. Most soap systems use stearic acid or palmitic acid, which are then neutralized with potassium hydroxide and compounded with a small amount of betaine. It has the advantages of rich foam, strong cleansing feeling and low cost. The amino acid system mainly uses sodium cocoyl glycinate, sodium methyl cocoyl taurate, potassium lauroyl sarcosinate and potassium lauroyl glutamate as the main surfactants, and then thickens by adding a variety of thickeners, such as PEG-150 distearate, acrylic acid (ester) copolymers and hydroxypropyl starch phosphate. There are many types of main surfactants in the surfactant system, some are based on AES, some are based on sodium lauroyl isethionate or sodium lauryl glucoside carboxylate. The system is thickened by combining amphoteric surfactants, inorganic salts and polymer thickeners. The foam performance is equivalent to that of the amino acid system, but the false slippery feeling after rinsing is more obvious.

[0003] With the development of the facial cleansing market, some composite systems have also appeared in recent years, such as the combination of amino acid surfactants and soap-based surfactants. It is compounded with a small amount of fatty acid salts and N-acyl amino acid salts. Although the foam density and cleansing feeling of the system are slightly improved, the improvement effect is limited due to the small amount of fatty acid salts. In terms of whitening effect, one is to add substances with whitening effect, and the other is to use whitening effect substances in combination with physical covering. Most of the whitening effect substances use niacinamide, mainly because of low cost, good effect and good stability. Although other ursolic acid, glabridin and ferulic acid have better effects, they are more expensive and easy to change color. There are also studies that use a variety of plant extracts as whitening ingredients, but the mechanism of action is not clear. Physical covering is mainly through the addition of titanium dioxide, pearl powder and other substances, so that the skin looks obviously whitening, so that consumers insist on using it to achieve a virtuous circle.

[0004] The products currently on the market, such as soap-based whitening cleansers, have a high pH value. Since most whitening actives are sensitive to pH values, they will be destroyed or degraded if they exist at high pH values ​​for a long time, resulting in a decrease in whitening effect and discoloration and taste changes in the product. If the amount of potassium hydroxide is directly reduced or citric acid is added to reduce the pH value to below 8.0, there will be almost no foam, the paste will even become rough, and stratification will occur due to the low neutralization degree of fatty acids. At present, there are studies on compounding amino acid surfactants or AES with soap-based systems, but due to the low soap content in some products, the cleaning power is insufficient and the cleansing feeling is poor. Some soap-based products are also compounded with a small amount of amino acids or AES and other surfactants. The system is still dominated by soap in general, and the pH value is still greater than 8, resulting in poor effect of whitening actives. The pH value of the amino acid system whitening cleanser is moderate, and the whitening actives can remain stable, but the foam volume and foam density are worse than the soap-based system, and the cleaning ability is relatively general. The amino acid system itself is difficult to thicken. Once a large amount of whitening active ingredients are added, the system is even more difficult to form. At this time, adding a large amount of thickener will greatly increase the product cost on the one hand, and on the other hand, it will seriously affect the application performance and foam volume of the cleanser, thereby affecting the consumer experience. The whitening cleanser of the surfactant system has better cleaning power, but it still cannot solve the problems of slow flushing, weak cleaning feeling and poor foam density. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a soap-based whitening cleanser. By optimizing the cleanser formula system, the pH of the provided cleanser is stabilized below 8.0, thereby solving the problem that the high pH value of the soap-based system leads to the inactivation and degradation of the whitening cleanser functional ingredients, and better meets the actual application needs.

[0006] On one hand, the present invention provides a soap-based whitening facial cleanser, which comprises, by mass percentage, at least 20% to 35% of natural oil soap solution, 15% to 50% of amino acid surfactant, 10% to 25% of zwitterionic surfactant, 0.1% to 2% of cationic high molecular polymer, 1% to 10% of thickener, 0.1% to 10% of whitening active ingredient, and the balance is made up of deionized water.

[0007] As a preferred technical solution, the soap-based whitening facial cleanser further comprises, by mass percentage, 0.1%-2% of a physical covering agent, wherein the physical covering agent comprises at least one of titanium dioxide, pearl powder and pearlescent flakes.

[0008] As a preferred technical solution, the soap-based whitening cleanser also includes 0.1%-1% fatty acid by mass percentage.

[0009] Preferably, the fatty acid is selected from at least one of oleic acid, linoleic acid and lauric acid.

[0010] As a preferred technical solution, the mass ratio of the natural oil soap solution, the amino acid surfactant, and the zwitterionic surfactant is (20-35): (20-50): (15-20).

[0011] As a preferred technical solution, the total mass ratio of the natural oil soap solution to the amino acid surfactant and the zwitterionic surfactant is 35:(30-40).

[0012] As a preferred technical solution, the natural oil soap liquid is selected from at least one of fatty acid potassium salt, fatty acid TEA salt, fatty acid diethanolamine salt, and fatty acid monoethanolamine salt, and is preferably at least one of potassium cocoate, potassium laurate, potassium myristate, TEA laurate, TEA myristic acid, and TEA cocoate.

[0013] Preferably, the natural oil soap liquid is TEA cocoate or a combination of TEA cocoate and potassium cocoate. Preferably, the mass ratio of TEA cocoate to potassium cocoate is (15-30):5, preferably 30:5.

[0014] As a preferred technical solution, the amino acid surfactant is selected from at least one of sodium cocoyl taurate, sodium myristoyl taurate, sodium lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl myristoyl taurate, sodium methyl lauroyl taurate, sodium laurate taurate, sodium cocoyl taurate, and sodium myristate taurate.

[0015] Preferably, the amino acid surfactant is a combination of sodium cocoyl taurate and sodium laurate taurate. Preferably, the mass ratio of sodium cocoyl taurate and sodium laurate taurate is (1-3):(1-2), preferably (1-1.5):1.

[0016] As a preferred technical solution, the zwitterionic surfactant is selected from at least one of lauryl hydroxysulfonyl betaine, cocoyl hydroxysulfonyl betaine, lauryl amidopropyl hydroxysulfonyl betaine, cocoamidopropyl betaine, lauryl amidopropyl betaine, cocoyl betaine and lauryl betaine.

[0017] Preferably, the zwitterionic surfactant is lauryl hydroxysulfonate.

[0018] As a preferred technical solution, the cationic high molecular polymer is selected from at least one of polyquaternium-7, polyquaternium-10, polyquaternium-22, polyquaternium-39, polyquaternium-47, and polyquaternium-43.

[0019] Preferably, the cationic high molecular polymer is a combination of polyquaternium-7 and polyquaternium-39 or polyquaternium-7 & polyquaternium-43.

[0020] As a preferred technical solution, the whitening active ingredient at least includes niacinamide;

[0021] Preferably, the whitening active ingredient further comprises at least one of α-arbutin and glabridin.

[0022] The soap-based whitening facial cleanser provided by the present invention forms a composite buffer system of natural oil soap liquid-amino acid surfactant-amphoteric surfactant by compounding natural oil soap liquid and amino acid surfactant and collocation of zwitterionic surfactant, the pH value of the soap-based whitening facial cleanser can be stabilized between 7.0-8.0, and the foam and washing feeling of the soap-based system can be maintained. In particular, TEA cocoate or a combination of TEA cocoate and potassium cocoate is used as the natural oil soap liquid, and the total mass ratio of the natural oil soap liquid to the amino acid surfactant and the zwitterionic surfactant is further controlled to be 35: (30-40), so that the provided soap-based whitening facial cleanser has a suitable viscosity to meet the actual use requirements. In addition, the irritation of the pure soap system is reduced by compounding amino acid surfactant and zwitterionic surfactant, the problem of insufficient cleaning power of a single amino acid facial cleanser is solved, and the problems of slow flushing speed, weak cleaning feeling and poor foam density are effectively solved while ensuring the cleaning ability.

[0023] As a preferred technical solution, the thickener is a cellulose thickener and / or an acrylate copolymer. Preferably, the thickener is selected from hydroxypropyl methylcellulose, hydroxyethyl cellulose, and acrylate polymers, preferably acrylate / stearyl alcohol polyether-20 methacrylate cross-linked polymer.

[0024] The soap-based whitening facial cleanser provided by the present invention solves the problem of difficult thickening of the whitening facial cleanser system by introducing acrylic acid (ester) / stearyl alcohol polyether-20 methacrylate cross-linked polymer, and still has a high viscosity under a high content of whitening components, while also increasing the density of the foam, with low product cost, avoiding the problem of reduced application performance and foam volume of the facial cleanser due to the introduction of a large amount of thickener, and ensuring the use experience of consumers.

[0025] Another aspect of the present invention provides a method for preparing a soap-based whitening facial cleanser, which comprises at least the following steps: premixing a thickener with deionized water at a mass ratio of 1:1 to obtain a thickener solution, and premixing a cationic high molecular polymer with deionized water at a mass ratio of 1:1 to obtain a cationic high molecular polymer solution; stirring and mixing a natural oil soap solution, an amino acid surfactant, and a remaining amount of deionized water, adding the thickener solution and stirring and mixing, adding a physical covering agent, a fatty acid, a cationic high molecular polymer solution, and niacinamide, stirring and mixing, cooling, adding 50-70wt% of an amphoteric surfactant, continuing to stir and cool to obtain a mixture, dispersing whitening active substances other than niacinamide with the remaining amount of the amphoteric surfactant, adding the mixture to the mixture, stirring and mixing, adjusting the pH range to 7.0-8.0, and discharging the mixture after passing the test.

[0026] Preferably, the preparation method of the soap-based whitening cleanser comprises the following steps:

[0027] (1) premixing a thickener with deionized water at a mass ratio of 1:1 to obtain a thickener solution, and premixing a cationic polymer with deionized water at a mass ratio of 1:1 to obtain a cationic polymer solution;

[0028] (2) stirring and mixing the natural oil soap solution, the amino acid surfactant, and the remaining deionized water at 80-85° C. and 10-15 rpm for 20-60 min to obtain a clear and transparent material 1;

[0029] (3) Adding a thickener solution to the clear and transparent material 1, the thickener solution addition time is controlled to be 15-25 minutes, stirring is started, the stirring speed is controlled to be 15-25 rpm, auxiliary homogenization is 500-1500 rpm, and the temperature is kept until it becomes clear and transparent, and there is almost no foam on the surface, at this time, the material 2 is obtained;

[0030] (4) adding a physical covering agent, fatty acid, cationic polymer solution, and nicotinamide to the material body 2, stirring and mixing to obtain a clear and transparent material body 3, and starting stirring and cooling;

[0031] (5) cooling to 60-65° C., adding 50-70 wt % of an amphoteric surfactant, and continuing to stir and cool to obtain a mixture;

[0032] (6) Cooling to 40-50° C., dispersing the whitening active ingredients except niacinamide with the remaining amount of amphoteric surfactant, adding the mixture to the mixture and stirring, adjusting the pH range to 7.0-8.0, and discharging the mixture after it passes the test.

[0033] Beneficial Effects

[0034] 1. The present invention provides a soap-based whitening cleanser. By optimizing the cleanser formula system, the pH value of the provided cleanser is stabilized below 8.0, thereby solving the problem that the high pH value of the soap-based system leads to the inactivation and degradation of the whitening cleanser's functional ingredients, and better meeting the actual application needs.

[0035] 2. The soap-based whitening facial cleanser provided by the present invention is compounded with natural oil soap solution and amino acid surfactant and matched with zwitterionic surfactant to form a composite buffer system of natural oil soap solution-amino acid surfactant-amphoteric surfactant. The pH value of the soap-based whitening facial cleanser can be stabilized between 7.0 and 8.0, and the foam and washing feeling of the soap-based system can be maintained.

[0036] 3. The present invention adopts TEA cocoate or a combination of TEA cocoate and potassium cocoate as natural oil soap liquid, and further controls the total mass ratio of natural oil soap liquid to amino acid surfactant and zwitterionic surfactant to be 35:(30-40), so that the provided soap-based whitening cleanser has a suitable viscosity to meet actual use requirements.

[0037] 4. The present invention reduces the irritation of the pure soap system by compounding amino acid surfactants and amphoteric surfactants, thereby solving the problem of insufficient cleaning power of a single amino acid facial cleanser. While ensuring the cleaning ability, it effectively solves the problems of slow flushing speed, weak cleaning feeling and poor foam density.

[0038] 5. The soap-based whitening cleanser provided by the present invention solves the problem of difficult thickening of the whitening cleanser system by introducing acrylic acid (ester) / stearyl alcohol polyether-20 methacrylate cross-linked polymer. It still has a high viscosity at a high content of whitening ingredients, and also increases the density of the foam. The product cost is low, and the problem of reduced application performance and foam volume of the cleanser caused by the introduction of a large amount of thickeners is avoided, thereby ensuring the consumer's usage experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The foam volume and sponginess test results of the facial cleansers provided in Examples 1-8 are shown in the figure. From left to right and from top to bottom, they correspond to Examples 1-8 respectively.

[0040] Figure 2 The foam volume and sponge density test results of the facial cleansers provided for Comparative Examples 1-7 are shown in the figure. From left to right and from top to bottom, they correspond to Comparative Examples 1-7 respectively. DETAILED DESCRIPTION

[0041] Examples 1-8

[0042] On the one hand, Examples 1-8 of the present invention provide a soap-based whitening cleanser, and the formula is shown in Table 1 in terms of mass percentage.

[0043] Table 1

[0044]

[0045]

[0046] On the other hand, embodiments 1-8 of the present invention provide a method for preparing a soap-based whitening cleanser, comprising the following steps:

[0047] (1) premixing a thickener with deionized water at a mass ratio of 1:1 to obtain a thickener solution, and premixing a cationic polymer with deionized water at a mass ratio of 1:1 to obtain a cationic polymer solution;

[0048] (2) stirring and mixing the natural oil soap solution, the amino acid surfactant, and the remaining deionized water at 84° C. and 15 rpm for 30 min to obtain a clear and transparent material 1;

[0049] (3) Adding a thickener solution to the clear and transparent material 1, the thickener solution addition time is controlled to be 20 minutes, stirring is started, the stirring speed is controlled to be 20 rpm, the auxiliary homogenization is 1000 rpm, and the temperature is kept until it is clear and transparent, and there is almost no foam on the surface, at this time, the material 2 is obtained;

[0050] (4) adding a physical covering agent, fatty acid, cationic polymer solution, and nicotinamide to the material body 2, stirring and mixing to obtain a clear and transparent material body 3, and starting stirring and cooling;

[0051] (5) cooling to 60° C., adding 60 wt % of an amphoteric surfactant, and continuing to stir and cool to obtain a mixture;

[0052] (6) Cooling to 45° C., dispersing the whitening active ingredients except niacinamide with the remaining amount of amphoteric surfactant, and adding the mixture to the mixture and stirring to mix. Adjusting the pH range is as shown in Table 3. After the test is qualified, the mixture is discharged.

[0053] Comparative Examples 1-7

[0054] Comparative Examples 1-7 of the present invention provide a soap-based whitening cleanser on the one hand, and the formula is shown in Table 2 in terms of mass percentage.

[0055] Table 2

[0056]

[0057]

[0058] Comparative Examples 1-7 of the present invention provide, on the other hand, a method for preparing a soap-based whitening cleanser, comprising the following steps: (1) premixing a thickener with deionized water at a mass ratio of 1:1 to obtain a thickener solution, and premixing a cationic polymer with deionized water at a mass ratio of 1:1 to obtain a cationic polymer solution;

[0059] (2) stirring and mixing the natural oil soap solution, the amino acid surfactant, and the remaining deionized water at 84° C. and 15 rpm for 30 min to obtain a clear and transparent material 1;

[0060] (3) Adding a thickener solution to the clear and transparent material 1, the thickener solution addition time is controlled to be 20 minutes, stirring is started, the stirring speed is controlled to be 20 rpm, the auxiliary homogenization is 1000 rpm, and the temperature is kept until it is clear and transparent, and there is almost no foam on the surface, at this time, the material 2 is obtained;

[0061] (4) adding a physical covering agent, fatty acid, cationic polymer solution, and nicotinamide to the material body 2, stirring and mixing to obtain a clear and transparent material body 3, and starting stirring and cooling;

[0062] (5) cooling to 60° C., adding 60 wt % of an amphoteric surfactant, and continuing to stir and cool to obtain a mixture;

[0063] (6) Cooling to 45° C., dispersing the whitening active ingredients except niacinamide with the remaining amount of amphoteric surfactant, and adding the mixture to the mixture and stirring to mix. Adjusting the pH range is as shown in Table 3. After the test is qualified, the mixture is discharged.

[0064] Performance Testing

[0065] 1. pH:

[0066] Take 1 g of the facial cleanser samples prepared in Examples 1 to 8 and Comparative Examples 1 to 7, add 9 g of deionized water, stir evenly until completely dissolved, keep warm, and measure the pH value with a pH tester. The results are shown in Table 3.

[0067] Table 3

[0068]

[0069] 2. Viscosity:

[0070] Appropriate amounts of the facial cleansing milk samples prepared in Examples 1 to 8 and Comparative Examples 1 to 7 were taken respectively, and the viscosities were tested at 25° C. using a viscometer (IKA Rotary Viscometer ROTAVISC Lo-vi). The results are shown in Table 4.

[0071] Table 4

[0072]

[0073] 3. Foam volume and density:

[0074] Take the same amount of 1.2g of the cleansing milk prepared in Examples 1 to 8 and Comparative Examples 1 to 7, add appropriate amount of tap water and foam by hand 40 times, record the foam state, and refer to the results. Figure 1 , Figure 2 .

[0075] 4. Clean feeling after washing:

[0076] The facial cleansing milks prepared in Examples 1 to 8 and Comparative Examples 1 to 7 were distributed to 15 volunteers respectively, and the samples were used to evaluate the cleansing sensation of the face after washing during the flushing process.

[0077] Evaluation criteria: 5 points for a very obvious sense of cleanliness, 4 points for a relatively clean feeling, 3 points for an average feeling, 2 points for a feeling of unclean and greasy feeling after flushing, and 1 point for a very greasy and unclean feeling.

[0078] The results are shown in Table 5.

[0079] Table 5

[0080]

[0081] 5. Moisturizing:

[0082] The facial cleansers prepared in Examples 1 to 8 and Comparative Examples 1 to 7 were distributed to 15 volunteers respectively, and the moisturizing properties of the products were evaluated 5 minutes after washing using the samples.

[0083] Evaluation criteria: 5 points for very moisturizing after washing, 4 points for moderately moisturizing, 3 points for average, 2 points for relatively tight and dry after washing, 1 point for very dry and tight after washing.

[0084] The results are shown in Table 6.

[0085] Table 6

[0086]

[0087] 6. Low temperature stability:

[0088] Take 50 grams of each of the facial cleansers prepared in Examples 1 to 8 and Comparative Examples 1 to 7, put them in a refrigerator at a low temperature of 5° C., refrigerate for 1 month, and observe whether the state of the samples changes.

[0089]

[0090] Examples 1 to 7 are all in a uniform and stable state at low temperatures and have a suitable viscosity. Examples 1 to 3 all have particles precipitated at low temperatures, while Comparative Examples 6 and 7 have increased viscosity at low temperatures and present a jelly state.

[0091] 6. Toxicology test

[0092] (1) Acute eye irritation test: The facial cleanser provided in Example 7 was used as the test substance, and the results of the acute eye irritation test of the test substance on rabbits were recorded (30 s rinse), as shown in Table 7.

[0093] (2) Acute skin irritation test: The facial cleanser provided in Example 7 was used as the test substance, and the results of the acute skin irritation test of the test substance on rabbits were recorded. See Table 8 for details.

[0094] Table 7

[0095]

[0096]

[0097]

[0098] Table 8

[0099] 7. Human safety trial test (internal laboratory internal control preliminary test). The facial cleanser provided in Example 7 was tested on humans. The results of the human trial test showed that there were no cases of adverse skin reactions among 30 people. The test results are shown in Table 9.

[0100] Table 9

[0101]

[0102] 8. Human open use freckle removal and whitening efficacy test (Chapter 8, Method 5, Method 2, Safety Technical Specifications for Cosmetics 2015 Edition) (Preliminary internal laboratory control test). The internal laboratory control conducted a preliminary screening of the cleanser provided in Example 7 for the ITA° index and the spot area ratio index. The number of people screened was greater than 30. The screening results are shown in Table 10.

[0103] Table 10

[0104]

Claims

1. A soap-based whitening cleanser, characterized in that: The raw materials for its preparation include at least 20% to 35% natural oil soap solution, 15% to 50% amino acid surfactant, 10% to 25% zwitterionic surfactant, 0.1% to 2% cationic high molecular polymer, 1% to 10% thickener, 0.1% to 10% whitening active substance, and deionized water to make up the balance.

2. The soap-based whitening facial cleanser according to claim 1, characterized in that: Calculated by mass percentage, the soap-based whitening facial cleanser also includes 0.1%-2% of a physical covering agent, and the physical covering agent includes at least one of titanium dioxide, pearl powder, and pearlescent flakes.

3. The soap-based whitening facial cleanser according to claim 1, characterized in that: In terms of mass percentage, the soap-based whitening facial cleanser also includes 0.1%-1% fatty acid, and the whitening active ingredient includes at least niacinamide.

4. The soap-based whitening facial cleanser according to claim 1, characterized in that: The mass ratio of the natural oil soap solution, the amino acid surfactant and the zwitterionic surfactant is (20-35): (20-50): (15-20).

5. The soap-based whitening facial cleanser according to claim 4, characterized in that: The total mass ratio of the natural oil soap solution to the amino acid surfactant and the zwitterionic surfactant is 35:(30-40).

6. The soap-based whitening facial cleanser according to claim 5, characterized in that: The natural oil soap liquid is selected from at least one of fatty acid potassium salt, fatty acid TEA salt, fatty acid diethanolamine salt, and fatty acid monoethanolamine salt, and is preferably at least one of potassium cocoate, potassium laurate, potassium myristic acid, TEA laurate, TEA myristic acid, and TEA cocoate.

7. The soap-based whitening facial cleanser according to claim 5, characterized in that: The amino acid surfactant is selected from at least one of sodium cocoyl taurate, sodium myristoyl taurate, sodium lauroyl taurate, sodium methyl cocoyl taurate, sodium methyl myristoyl taurate, sodium methyl lauroyl taurate, sodium laurate taurate, sodium cocoyl taurate, and sodium myristate taurate.

8. The soap-based whitening facial cleanser according to claim 5, characterized in that: The zwitterionic surfactant is selected from at least one of lauryl hydroxysulfonyl betaine, cocoyl hydroxysulfonyl betaine, lauryl amidopropyl hydroxysulfonyl betaine, cocoamidopropyl betaine, lauryl amidopropyl betaine, cocoyl betaine and lauryl betaine.

9. The soap-based whitening facial cleanser according to claim 1, characterized in that: The cationic high molecular polymer is selected from at least one of polyquaternium-7, polyquaternium-10, polyquaternium-22, polyquaternium-39, polyquaternium-47 and polyquaternium-43.

10. A method for preparing a soap-based whitening cleanser according to any one of claims 3 to 9, characterized in that: The method comprises at least the following steps: premixing a thickener with deionized water at a mass ratio of 1:1 to obtain a thickener solution, and premixing a cationic high molecular polymer with deionized water at a mass ratio of 1:1 to obtain a cationic high molecular polymer solution; stirring and mixing a natural oil soap solution, an amino acid surfactant, and a remaining amount of deionized water, adding the thickener solution and stirring and mixing, adding a physical covering agent, a fatty acid, a cationic high molecular polymer solution, and nicotinamide, stirring and mixing, cooling, adding 50-70wt% of an amphoteric surfactant, continuing to stir and cool to obtain a mixture, dispersing whitening active substances except nicotinamide with the remaining amount of the amphoteric surfactant, adding the mixture to the mixture, stirring and mixing, adjusting the pH range to 7.0-8.0, and discharging the mixture after passing the test.

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