Mild depilating composition containing sulfhydryl compound as well as preparation method and application of mild depilating composition

Abstract

The invention provides a mild depilating composition containing a sulfhydryl compound as well as a preparation method and application of the mild depilating composition, and relates to the technical field of daily chemical products. The unhairing composition comprises the following raw materials: L-cysteine wrapped by microcapsules, bromelain, a water dragon extract, a calendula extract, a pH regulator, a humectant and water. Through specific components and specific dosage, the prepared unhairing composition is better in unhairing effect, higher in safety, milder, easier to accept in taste and better in stability.

Description

Mild hair removal compositions containing thiol compounds, their preparation methods and applications Technical Field

[0001] This invention relates to the field of daily chemical products technology, specifically to a mild hair removal composition containing thiol compounds, its preparation method, and its application. Background Technology

[0002] As people's living standards improve, they are paying more and more attention to the appearance and care of their skin. Hair on the body, such as hand, foot, and armpit hair, is easily exposed when wearing clothes in summer, affecting appearance, especially for women who care about their looks. As a result, hair removal products have emerged. However, current hair removal products are not very effective, often leaving a large amount of hair residue and resulting in incomplete hair removal.

[0003] Hair removal products work by using chemicals to dissolve the hair structure, thus achieving hair removal. Current hair removal formulations contain many irritating ingredients for rapid hair removal, such as salts of thioglycolic acids, known as disulfide bond breakers. When applied, these thioglycolic acid salts act as active ingredients, attacking the hair shaft (the part closest to the skin surface), disrupting the hair shaft's structure.

[0004] The breaking of disulfide bonds in keratin makes the hair shaft fragile and causes it to break on the skin surface. This is similar to cutting hair off the skin with a razor, except that a chemical hair removal method is used, and the root of the hair remains in the hair follicle after it breaks.

[0005] For example, Chinese patent application CN114053180A discloses a hair removal composition, its preparation method, and its application. The hair removal composition comprises the following raw materials in parts by weight: 1.5-5 parts thickener, 2-6 parts emulsifier, 3-6 parts surfactant, 3-5 parts hair removal agent, 1-2 parts pH adjuster, 0.5-1.5 parts compatibilizer, 1-5 parts physical foaming agent, and 50-70 parts water; the hair removal agent is selected from one or two of calcium thioglycolate and potassium thioglycolate. Chinese patent application CN118615179A discloses a hair removal composition and its preparation method. The hair removal composition comprises the following components in parts by weight: 2-4 parts potassium thioglycolate, 0.1-0.5 parts citrus fruit extract, 0.1-0.5 parts kava pepper root extract, 2-8 parts moisturizer, 5-10 parts emollient, 1-3 parts thickener, 5-8 parts emulsifier, 1-3 parts co-emulsifier, 0.5-2 parts pH adjuster, 0.1-0.5 parts preservative, 0.02-0.1 parts fragrance, and water to a total of 100 parts. The active ingredient in the above-mentioned hair removal agent is a salt of thiohydroxy acid.

[0006] However, these synthetically produced salts of thioglycolic acids are highly irritating and can cause redness, swelling, and even allergies after hair removal. For example, thioglycolic acid is highly corrosive; ammonium thioglycolate is not alkali-resistant and has a strong odor, making it unsuitable for hair removal creams; sodium / potassium thioglycolate is also unsuitable due to its highly reactive metal ions and strong irritant properties; and while calcium thioglycolate is more inert and milder than metals, its hair removal effect is relatively average, and improper use can cause irritation or poor results.

[0007] Based on this, it is of great significance to develop a hair removal cream that uses natural thiol compounds to replace the salts of thiol hydroxy acids, thereby solving the problems of existing technologies such as high irritation and unpleasant odor caused by the salts of thiol hydroxy acids, which cannot meet the higher requirements of sensitive skin for safety and irritation. Summary of the Invention

[0008] To address the aforementioned problems, this invention provides a mild hair removal composition containing thiol compounds, its preparation method, and its application. On the one hand, it solves the problems existing in the prior art, such as the high irritation and unpleasant odor caused by salts of thiol hydroxy acids, which cannot meet the higher requirements for safety and irritation of sensitive skin. On the other hand, it solves the problems of insufficient purity and instability of natural thiol compounds.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0010] On one hand, the present invention provides a mild hair removal composition containing thiol compounds, comprising the following ingredients: microencapsulated L-cysteine, bromelain, water dragon extract, calendula extract, pH adjuster, moisturizer, and water.

[0011] Preferably, the method for preparing the microencapsulated L-cysteine ​​includes the following steps: (1) mixing soybeans with 5.5-6.0 mol / L hydrochloric acid, hydrolyzing to obtain a hydrolysate; (2) adjusting the pH of the hydrolysate to 4.5-5.0, separating to obtain a supernatant; (3) passing the supernatant through a strongly acidic cation exchange column, eluting with 2.0-2.5 mol / L hydrochloric acid, collecting the eluent; concentrating and cooling to crystallize, and vacuum drying at 60-70℃ to obtain L-cysteine; (4) dissolving Eudragit S100 in a 50-60 wt% ethanol aqueous solution to obtain a 10-20 wt% Eudragit S100 solution, then mixing it with L-cysteine, homogenizing, and spray drying to obtain microencapsulated L-cysteine.

[0012] Preferably, in step (1), the soybeans need to be crushed and passed through a 100-200 mesh sieve.

[0013] Preferably, in step (1), the ratio of soybean to hydrochloric acid is 1g:10-15mL.

[0014] Preferably, in step (1), the mixing is ultrasound.

[0015] Preferably, in step (1), the hydrolysis is boiling reflux hydrolysis, and the time is 6-8 hours.

[0016] Preferably, in step (2), the pH is adjusted to 4.5-5.0 with citric acid.

[0017] Preferably, in step (3), the preparation of the strongly acidic cation exchange column is as follows: the resin is pretreated by soaking in 0.5 mol / L hydrochloric acid for 1 h, and then washed until neutral before being packed into the column.

[0018] Preferably, in step (3), the cooling crystallization is performed by mixing the concentrated eluent with a mixture of ethanol and acetone in a volume ratio of 10:1, cooling the mixture from room temperature to 0°C at 2°C / min, then cooling it to -5°C at 1°C / min, and stirring at 60-80 rpm to crystallize.

[0019] Preferably, in step (4), the mass of L-cysteine ​​is 5%-15% of the mass of the Eudragit S100 solution.

[0020] Preferably, in step (4), the pressure of the homogenization is 35-40 MPa.

[0021] Preferably, in step (4), the inlet air temperature of the spray dryer is 150-220℃ and the outlet air temperature is 80-100℃.

[0022] Among them, Water Dragon (also known as Pond Snake, River Dragon, etc.) refers to the whole herb or above-ground parts of the plant *Ludwigia* in the family Onagraceae; the species corresponding to the scientific name is a perennial floating / rising herbaceous plant.

[0023] Preferably, the preparation method of the water dragon extract includes the following steps: drying and pulverizing the whole water dragon herb, adding 50wt%-70wt% ethanol solution and extracting at 70-90℃ for 1-3 hours to obtain the extract.

[0024] Preferably, the ratio of the whole herb to the ethanol solution is 1g:6-10mL.

[0025] Preferably, the ingredients, by weight, include the following: 5-15 parts microencapsulated L-cysteine, 0.5-2 parts bromelain, 1-3 parts water dragon extract, 2-5 parts calendula extract, 5-10 parts moisturizer, and 50-80 parts water, with a pH adjuster adjusted to pH 8-9.

[0026] More preferably, the ingredients, by weight, include the following: 10 parts microencapsulated L-cysteine, 1 part bromelain, 2 parts water dragon extract, 4 parts calendula extract, 8 parts humectant, and 55 parts water, with a pH adjuster adjusted to pH 8.5.

[0027] Preferably, the pH adjuster is potassium carbonate.

[0028] Preferably, the moisturizer is selected from at least one of glycerin, butylene glycol, propylene glycol, urea, sodium hyaluronate, or polyethylene glycol.

[0029] More preferably, the moisturizer is selected from at least one of glycerin, butylene glycol, or sodium hyaluronate.

[0030] Secondly, the present invention provides a method for preparing the hair removal composition, comprising the following steps: mixing raw materials.

[0031] Thirdly, the present invention provides the use of the hair removal composition in the preparation of hair removal products.

[0032] Preferably, the hair removal product also includes excipients acceptable in the skin care industry.

[0033] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention can achieve the following effects by extracting natural L-cysteine ​​from plant protein: (1) Natural thiol compounds are generally less irritating to the skin and are less likely to cause contact dermatitis or chemical burns, and are safer; (2) They cause less damage to the skin barrier, are suitable for sensitive skin, and are more gentle; (3) Natural ingredients have lower sensitization, which reduces the risk of use for people with allergies; (4) Plant protein hydrolysates have lower irritation, which is suitable for the application of daily chemical products that are sensitive to animal-derived ingredients.

[0034] 2. This invention solves the problem of poor stability of natural thiol compounds by preparing microencapsulated L-cysteine, further reducing irritation, avoiding contact with air and moisture, releasing activity only after being applied to the skin, and extending the product's shelf life.

[0035] 3. This invention significantly improves hair removal effect, significantly reduces irritation, and improves the taste of the composition by combining microencapsulated L-cysteine ​​with bromelain, water dragon extract, and calendula extract.

[0036] 4. The hair removal composition prepared by the present invention through specific components and specific dosages has better hair removal effect, higher safety, gentler, more acceptable taste, and better stability. Detailed Implementation

[0037] To make the technical means, creative features, achieved objectives, and effects of this invention readily understandable, the invention is further illustrated below with specific embodiments. However, these embodiments are merely preferred embodiments and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments described herein without creative effort are all within the scope of protection of this invention. It is worth noting that the raw materials used in this invention are all common commercially available products, and their sources are not specifically limited. The technical and scientific terms used in the embodiments have the meanings commonly understood by those skilled in the art to which this invention pertains.

[0038] Calendula extract: purchased from Wuhan Kemic Biomedical Technology Co., Ltd., brand: Kemic, CAS: 84776-23-8, content 5%.

[0039] Water dragon extract: The whole water dragon herb is dried and pulverized, and 50wt% ethanol solution is added (material-liquid ratio of 1g:6mL). It is extracted at 70℃ for 2h, and then ethanol is added until the final ethanol concentration is 70wt% (material-liquid ratio of 1g:10mL). It is extracted at 90℃ for 1h, and the extracts are combined and dried to obtain water dragon extract.

[0040] Example 1 A mild hair removal composition containing thiol compounds, comprising, by weight, the following ingredients: 10 parts microencapsulated L-cysteine, 1 part bromelain, 2 parts water dragon extract, 4 parts calendula extract, 8 parts glycerin and 55 parts water, with the pH adjusted to 8.5 by potassium carbonate.

[0041] The method for preparing a mild hair removal composition containing thiol compounds is as follows: mix the above raw materials evenly.

[0042] The preparation method of the microcapsule-encapsulated L-cysteine ​​includes the following steps: (1) Soybeans are crushed, passed through a 100-200 mesh sieve, and ultrasonically mixed with 5.8 mol / L hydrochloric acid at a material-to-liquid ratio of 1 g:12 mL. The mixture is then hydrolyzed at 110°C for 7 h to obtain a hydrolysate; (2) The hydrolysate is adjusted to pH 4.5 with citric acid, separated, and a supernatant is obtained; (3) The supernatant is passed through a strongly acidic cation exchange column and eluted with 2.2 mol / L hydrochloric acid. The eluent containing cysteine ​​is collected; after concentration, the mixture is cooled and crystallized. The specific operation of cooling and crystallization is as follows: the concentrated eluent is mixed with a mixture of ethanol and acetone at a volume ratio of 10:1, and the temperature is lowered from room temperature to 0°C at 2°C / min, then to -5°C at 1°C / min, and the temperature is maintained at 60-80°C. Crystallize by stirring at rpm; then dry under vacuum at 65°C to obtain L-cysteine; the preparation of the strong acid cation exchange column is as follows: the resin is pretreated by soaking in 0.5 mol / L hydrochloric acid for 1 h, then washed until neutral and packed into the column; (4) Eudragit S100 is dissolved in 55 wt% ethanol aqueous solution to obtain 15 wt% Eudragit S100 solution, then mixed with L-cysteine, the mass of L-cysteine ​​being 10% of the mass of Eudragit S100 solution, homogenized, homogenized at 38 MPa, spray dried, inlet air temperature being 200°C, outlet air temperature being 90°C, to obtain microencapsulated L-cysteine.

[0043] Example 2 A mild hair removal composition containing thiol compounds, comprising the following ingredients by weight: 5 parts microencapsulated L-cysteine, 2 parts bromelain, 1 part water dragon extract, 2 parts calendula extract, 5 parts sodium hyaluronate and 50 parts water, with the pH adjusted to 8.0 by potassium carbonate.

[0044] The method for preparing a mild hair removal composition containing thiol compounds is as follows: mix the above raw materials evenly.

[0045] The preparation method of the microcapsule-encapsulated L-cysteine ​​includes the following steps: (1) Soybeans are crushed, passed through a 100-200 mesh sieve, and ultrasonically mixed with 5.5 mol / L hydrochloric acid at a material-to-liquid ratio of 1 g:15 mL. The mixture is then hydrolyzed at 105°C for 8 h to obtain a hydrolysate; (2) The hydrolysate is adjusted to pH 4.8 with citric acid, separated, and a supernatant is obtained; (3) The supernatant is passed through a strongly acidic cation exchange column and eluted with 2.5 mol / L hydrochloric acid. The eluent containing cysteine ​​is collected; after concentration, the mixture is cooled and crystallized. The specific operation of cooling and crystallization is as follows: the concentrated eluent is mixed with a mixture of ethanol and acetone at a volume ratio of 10:1, and the temperature is lowered from room temperature to 0°C at 2°C / min, then to -5°C at 1°C / min, and the temperature is maintained at 60-80°C. Crystallize by stirring at rpm; then dry under vacuum at 70°C to obtain L-cysteine; the preparation of the strong acid cation exchange column is as follows: the resin is pretreated by soaking in 0.5 mol / L hydrochloric acid for 1 h, then washed until neutral and packed into the column; (4) Eudragit S100 is dissolved in 60 wt% ethanol aqueous solution to obtain 10 wt% Eudragit S100 solution, then mixed with L-cysteine, the mass of L-cysteine ​​being 5% of the mass of Eudragit S100 solution, homogenized, homogenized at 40 MPa, spray dried, inlet air temperature being 150°C, outlet air temperature being 100°C, to obtain microencapsulated L-cysteine.

[0046] Example 3 A mild hair removal composition containing thiol compounds, comprising, by weight, the following ingredients: 15 parts microencapsulated L-cysteine, 0.5 parts bromelain, 3 parts water dragon extract, 5 parts calendula extract, 10 parts butylene glycol, and 80 parts water, with the pH adjusted to 9.0 by potassium carbonate.

[0047] The method for preparing a mild hair removal composition containing thiol compounds is as follows: mix the above raw materials evenly.

[0048] The preparation method of the microcapsule-encapsulated L-cysteine ​​includes the following steps: (1) Soybeans are crushed, passed through a 100-200 mesh sieve, and ultrasonically mixed with 6.0 mol / L hydrochloric acid at a material-to-liquid ratio of 1 g:10 mL. The mixture is then hydrolyzed at 115°C for 6 h to obtain a hydrolysate; (2) The hydrolysate is adjusted to pH 5.0 with citric acid, separated, and a supernatant is obtained; (3) The supernatant is passed through a strongly acidic cation exchange column and eluted with 2.0 mol / L hydrochloric acid. The eluent containing cysteine ​​is collected; after concentration, the mixture is cooled and crystallized. The specific operation of cooling and crystallization is as follows: the concentrated eluent is mixed with a mixture of ethanol and acetone at a volume ratio of 10:1, and the temperature is lowered from room temperature to 0°C at 2°C / min, then to -5°C at 1°C / min, and the temperature is maintained at 60-80°C. Crystallize by stirring at rpm; then dry under vacuum at 60°C to obtain L-cysteine; the preparation of the strong acid cation exchange column is as follows: the resin is pretreated by soaking in 0.5 mol / L hydrochloric acid for 1 h, then washed until neutral and packed into the column; (4) Eudragit S100 is dissolved in 50 wt% ethanol aqueous solution to obtain 20 wt% Eudragit S100 solution, then mixed with L-cysteine, the mass of L-cysteine ​​being 15% of the mass of Eudragit S100 solution, homogenized, homogenized at 35 MPa, spray dried, inlet air temperature being 220°C, outlet air temperature being 80°C, to obtain microencapsulated L-cysteine.

[0049] Comparative Example 1: A mild hair removal composition containing a thiol compound, which is the same as Example 1 except for the amount of the component.

[0050] The product comprises the following ingredients by weight: 20 parts microencapsulated L-cysteine, 0.4 parts bromelain, 5 parts water dragon extract, 6 parts calendula extract, 4 parts glycerin, and 44.6 parts water, with the pH adjusted to 8.5 by potassium carbonate.

[0051] Comparative Example 2: A mild hair removal composition containing a thiol compound, which, compared to Example 1, replaces the active ingredient with microencapsulated potassium thioglycolate, and is otherwise identical to Example 1.

[0052] Eudragit S100 was dissolved in a 50 wt% aqueous ethanol solution to obtain a 20 wt% Eudragit S100 solution, which was then mixed with potassium thioglycolate, the mass of which was 15% of the mass of the Eudragit S100 solution. The mixture was homogenized at a homogenization pressure of 35 MPa and spray-dried at an inlet air temperature of 220°C and an outlet air temperature of 80°C to obtain microencapsulated potassium thioglycolate.

[0053] Comparative Example 3: A mild hair removal composition containing a thiol compound, which, compared to Example 1, replaces bromelain with the same amount of alkaline protease by mass, otherwise remains the same as Example 1.

[0054] Comparative Example 4: A mild hair removal composition containing thiol compounds, compared to Example 1, except that the water dragon extract was replaced with the same mass fraction of kava pepper root extract, and the calendula extract was replaced with the same mass fraction of citrus fruit extract, otherwise the same as Example 1.

[0055] Test Example 1: Skin Irritation Test: The conjunctival sac of the rabbit eye is a sensitive area and is easily irritated. In this test, 35 adult, healthy rabbits weighing between 1.5 and 2.0 kg were randomly divided into 7 groups of 5 rabbits each. The 7 groups of rabbits were subjected to a rabbit eye irritation test corresponding to the hair removal compositions obtained in Examples 1-3 and Comparative Examples 1-4, respectively.

[0056] Experimental Method: 0.5g of the hair removal compositions obtained in Examples 1-3 and Comparative Examples 1-4 were dissolved in 20mL of deionized water and stirred until homogeneous. 0.1mL of the corresponding group's product solution was dripped into the conjunctival sac of rabbits, and the eyes were passively closed for 1 minute. Changes in the eyes of the rabbits were recorded at 12 hours, 1 day, 2 days, 3 days, and 7 days after treatment. The results were then summarized.

[0057] The experimental results are as follows: In the test rabbits of Examples 1-3 and Comparative Example 3, no congestion, edema, cloudiness, or discharge was observed in the cornea, conjunctiva, or iris of the eyes of any group of rabbits 12 hours, 1 day, 2 days, 3 days, or 7 days after drug application. Their activity and diet remained normal. This indicates that the hair removal compositions of Examples 1-3 are non-irritating to the eyes of rabbits, and the hair removal cream formulation of this example is mild and non-irritating, suitable even for sensitive skin.

[0058] In comparative groups 1-2 and 4, the eyes of the rabbits tested showed slight congestion of the cornea, conjunctiva, and iris at 12 hours, 1 day, and 2 days after drug administration. No abnormalities such as edema, cloudiness, or discharge were observed, and their activity and diet were normal.

[0059] Test Example 2: Hair Removal Effect. The hair removal compositions prepared in Examples 1-3 and Comparative Examples 1-4 were used as test samples to evaluate the effectiveness of the hair removal compositions.

[0060] The testing method is as follows: Seventy healthy women with sensitive skin and a desire for hair removal were selected as subjects. Each subject was randomly divided into seven groups of ten. An appropriate amount of test sample was applied to the underarms or legs where there was body hair, ensuring complete coverage. After waiting 5 minutes, the sample was gently wiped away against the direction of hair growth with a tissue, and then rinsed thoroughly with water. After the test, each subject rated the hair removal effect, gentleness, and odor tolerance of the test sample. The ratings for hair removal effect, gentleness, and odor tolerance were all on a 10-point scale, with 1 being the worst and 10 the best. Specific rating criteria are shown in Table 1. The test results are the average of each group's scores, as shown in Table 2.

[0061] Table 1

[0062] Table 2

[0063] As shown in Table 2, compared with the comparative example, the hair removal composition prepared in the embodiments of the present invention exhibits significantly improved hair removal effect, gentleness, and odor acceptability. This indicates that the hair removal composition obtained under the specific components and proportions of the present invention achieves further improved hair removal effect while significantly reducing irritation and optimizing odor acceptability, thus meeting the needs of a wide range of consumers.

[0064] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A mild hair removal composition containing a thiol compound, characterized in that, It includes the following ingredients: microencapsulated L-cysteine, bromelain, water dragon extract, calendula extract, pH adjuster, humectant, and water.

2. The hair removal composition according to claim 1, characterized in that, The method for preparing the microencapsulated L-cysteine ​​includes the following steps: (1) Soybeans are mixed with 5.5-6.0 mol / L hydrochloric acid and hydrolyzed to obtain a hydrolysate; (2) The pH of the hydrolysate is adjusted to 4.5-5.0, separated, and a supernatant is obtained; (3) The supernatant is passed through a strongly acidic cation exchange column and eluted with 2.0-2.5 mol / L hydrochloric acid. The eluent is collected, concentrated, cooled and crystallized, and vacuum dried at 60-70℃ to obtain L-cysteine; (4) Eudragit S100 is dissolved in 50-60 wt% ethanol aqueous solution to obtain 10-20 wt% Eudragit S100 solution, which is then mixed with L-cysteine, homogenized, and spray-dried to obtain microencapsulated L-cysteine.

3. The hair removal composition according to claim 2, characterized in that, In step (1), the soybeans need to be crushed and passed through a 100-200 mesh sieve; the ratio of soybeans to hydrochloric acid is 1g:10-15mL; the mixing is ultrasonic; the hydrolysis is boiling reflux hydrolysis for 6-8 hours.

4. The hair removal composition according to claim 2, characterized in that, In step (3), the cooling crystallization is as follows: the concentrated eluent is mixed with a mixture of ethanol and acetone in a volume ratio of 10:1, and the mixture is cooled from room temperature to 0°C at 2°C / min, and then cooled to -5°C at 1°C / min, while stirring at 60-80 rpm for crystallization.

5. The hair removal composition according to claim 2, characterized in that, In step (4), the mass of L-cysteine ​​is 5%-15% of the mass of Eudragit S100 solution; the homogenization pressure is 35-40 MPa; the inlet air temperature of the spray drying is 150-220℃ and the outlet air temperature is 80-100℃.

6. The hair removal composition according to claim 1, characterized in that, By weight, it includes the following ingredients: 5-15 parts microencapsulated L-cysteine, 0.5-2 parts bromelain, 1-3 parts water dragon extract, 2-5 parts calendula extract, 5-10 parts moisturizer, and 50-80 parts water, with pH adjusted to 8-9 by pH adjuster.

7. The hair removal composition according to claim 1, characterized in that, The preparation method of the water dragon extract includes the following steps: drying and pulverizing the whole water dragon herb, adding 50wt%-70wt% ethanol solution and extracting at 70-90℃ for 1-3 hours to obtain the extract.

8. A method for preparing the hair removal composition according to any one of claims 1-7, characterized in that, The process includes the following steps: mixing the raw materials.

9. The use of the hair removal composition according to any one of claims 1-7 in the preparation of hair removal products.

10. The application according to claim 9, characterized in that, The hair removal products also include excipients acceptable in the skincare industry.

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