Amino acid liquid crystal composition and method of making same

Abstract

This invention relates to the field of daily cosmetics technology, specifically to an amino acid soft crystal composition and its preparation method. The amino acid soft crystal composition comprises the following components by weight: 15-25 parts amino acid complex, 0.5-2 parts thickener, 0.5-2 parts dispersant, 2-10 parts moisturizer, 0.05-1 part preservative, and 70-90 parts deionized water. The amino acid complex is composed of sodium cocoylaminoalanine, potassium cocoylglycinate, and lauroylalanine, forming a stable amino acid crystal matrix with specific thickeners and dispersants. The product is clear and transparent, has a smooth and moisturizing feel when applied to the skin, and quickly melts into fine, moisturizing beads upon application.

Description

Technical Field

[0001] This invention relates to the field of daily cosmetics technology, specifically to an amino acid soft crystal composition and its preparation method. Background Technology

[0002] One of the main causes of skin aging is the loss of collagen (a type of protein), which leads to the breakage of collagen peptide bonds and elastic networks that support the skin. This disrupts the helical network structure, causing skin tissue to oxidize, atrophy, and collapse. Consequently, the skin becomes dry, wrinkled, loose, and lacks elasticity. Therefore, replenishing collagen is essential to delay aging. Since amino acids are the basic building blocks of proteins in living organisms, they can stimulate skin cells to synthesize collagen, improving skin elasticity and firmness. Therefore, cosmetics with amino acids as their main ingredient have gradually become a market hotspot in recent years.

[0003] Amino acid cosmetics, with their gentle, safe, and effective characteristics, have gained widespread popularity among consumers. The unique amino and carboxyl group structures of amino acids give them excellent moisturizing properties. By regulating the moisture balance of the stratum corneum on the skin's surface, they improve the skin barrier function and alleviate discomfort such as redness, swelling, and itching. Simultaneously, amino acids can inhibit inflammatory responses, reduce skin sensitivity, and enhance skin resistance. By binding to stratum corneum proteins on the skin's surface, amino acids promote skin metabolism, improve skin transparency, achieve whitening, inhibit melanin production, and reduce pigmentation. Commonly used amino acids in cosmetics include glycine, glutamic acid, alanine, serine, aspartic acid, and leucine. Different types of amino acids have different functions in cosmetics; for example, glutamic acid has a moisturizing effect, arginine helps with skin repair, and proline can enhance the skin barrier function.

[0004] Patent CN113171331B discloses an ice crystal amino acid shower gel containing glycerin, a complex surfactant, taurine, natural plant extracts, acrylate copolymers, cocamide DEA, fragrance, preservatives, and deionized water. By using a specific composition of complex surfactants, suspending stabilizers, and natural plant extracts, the shower gel achieves a unique ice crystal appearance, providing strong moisturizing power without being greasy, while also offering gentle cleansing and skin-nourishing effects. Meanwhile, patent CN114053172B discloses an ice crystal amino acid crystal composition. By adding a supersaturated active amino acid component—taurine—and using it in combination with specific complex polyols, emulsifying stabilizers, and suspending stabilizers, the precipitated taurine crystals can be evenly distributed in the composition. When applied to leave-on cosmetic products, this provides highly effective skincare. However, due to the precipitation of taurine crystals, the aforementioned ice crystal amino acid products have a fine grainy feel during use, which may not be suitable for consumers with thin stratum corneum. Therefore, a gentler product needs to be developed. Summary of the Invention

[0005] Based on the deficiencies of the prior art, the present invention provides an amino acid soft crystal composition, its preparation method and application. By scientifically compounding three amino acid surfactants, sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine, and comprehensively applying specific thickeners and dispersants, an amino acid crystalline product with a soft and clear effect is obtained, which has a softer skin feel and a better cleansing effect.

[0006] This invention provides an amino acid soft crystal composition comprising the following components by weight: 15-25 parts amino acid compound, 0.5-2 parts thickener, 0.5-2 parts dispersant, 2-10 parts humectant, 0.05-1 part preservative, and 70-90 parts deionized water; The amino acid complex is composed of sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine in a mass ratio of (3-5):(2-5):(10-15). The thickener is composed of an acrylic (ester) / C12-22 alkanol methacrylate copolymer, sodium alginate, and hydroxyethyl cellulose in a mass ratio of (0.1-0.5):(0.2-0.7):(0.3-0.8). The dispersant is composed of oleyl erucic acid ester and silachlorite hydropyroxene in a mass ratio of (0.3-1):(0.2-1).

[0007] Preferably, the amino acid complex is composed of sodium cocoylaminoalanine, potassium cocoylglycinate, and lauroylalanine in a mass ratio of (3-4):(2-4):(11-13).

[0008] Preferably, the thickener is composed of an acrylic (ester) / C12-22 alkanol methacrylate copolymer, sodium alginate and hydroxyethyl cellulose in a mass ratio of (0.2-0.4):(0.3-0.6):(0.5-0.6).

[0009] Preferably, the dispersant is composed of oleyl erucic acid ester and silachlorite hydropyroxene in a mass ratio of (0.5-0.8):(0.5-0.7).

[0010] Preferably, the moisturizer is selected from one or more of hyaluronic acid, ceramide, butylene glycol, propylene glycol, polyethylene glycol, urea, sodium lactate, and sodium polyaspartate.

[0011] Preferably, the preservative is selected from one or more of phenoxyethanol, methylparaben, ethylparaben, propylparaben, sodium benzoate, potassium sorbate, and iodopropynylcarbamate.

[0012] The present invention further provides a method for preparing the above-mentioned amino acid soft crystal composition, comprising the following steps: (1) Sodium alginate and hydroxyethyl cellulose are dispersed in 2 / 5-3 / 5 deionized water and heated. Acrylic (ester) / C12-22 alkanol methacrylate copolymer and dispersant are added and homogenized. (2) The amino acid complex was dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add humectant, preservative and amino acid solution to step (1), stir well, and cool to obtain the product.

[0013] Preferably, the heating temperature in step (1) is 75-85℃.

[0014] Preferably, the homogenization pressure in step (1) is 40-80 MPa, and the cycle is repeated 3-5 times.

[0015] The present invention further provides an amino acid soft crystal cosmetic, comprising the above-mentioned amino acid soft crystal composition or the amino acid soft crystal composition prepared by the above-mentioned preparation method.

[0016] Preferably, the cosmetics include, but are not limited to, facial cleansers, shower gels, bath oils, and shampoos.

[0017] The beneficial effects of this invention are as follows: 1. Sodium cocoylaminoalanine, potassium cocoyl glycinate, and lauroyl alanine are scientifically formulated surfactants that offer both highly effective and gentle cleansing, as well as long-lasting moisturizing and repairing benefits. Combined with specific thickeners such as acrylates / C12-22 alkanol methacrylate copolymer, sodium alginate, and hydroxyethyl cellulose, the system generates a dense and highly stable amino acid crystal matrix. Furthermore, the dispersant effectively inhibits the aggregation and sedimentation of amino acid crystals, ensuring uniform dispersion of crystals throughout the system and maintaining overall homogeneity and stability, thus preventing quality issues such as layering, clumping, and precipitation.

[0018] 2. The amino acid crystal structure of this application gives the product a clear and translucent appearance. It has a smooth and moisturizing feel when applied to the skin. When gently rubbed onto the skin, the crystals quickly melt into fine, moisturizing beads upon contact with the skin's surface temperature and slight friction, significantly reducing skin friction damage during washing and minimizing the risk of redness and stinging. After melting, the beads form a thin, moisturizing film, slowing down moisture loss. After washing, the skin is soft and supple without feeling dry, balancing cleansing, soothing, and long-lasting moisturizing power, making it suitable for all skin types, including sensitive and dry skin. Attached Figure Description

[0019] Figure 1 This is a photograph of the amino acid soft crystal composition of Example 1. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1 This embodiment provides an amino acid flexible crystal composition, comprising the following components: Table 1. Components of the Amino Acid Soft Crystal Composition

[0022] The preparation method of the above-mentioned amino acid soft crystal composition includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose were dispersed in 40 parts of deionized water and heated to 80°C. Acrylic (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 60 MPa for 4 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add hyaluronic acid, phenoxyethanol and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0023] A photograph of the amino acid soft crystal composition is attached. Figure 1 .

[0024] This embodiment also provides an amino acid soft crystal shower gel, comprising the above-mentioned amino acid soft crystal composition.

[0025] Example 2 This embodiment provides an amino acid flexible crystal composition, comprising the following components: Table 2 Components of Amino Acid Soft Crystal Composition

[0026] The preparation method of the above-mentioned amino acid soft crystal composition includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose were dispersed in 28 parts of deionized water and heated to 75°C. Acrylic (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 40 MPa for 5 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add polyethylene glycol-8, methylparaben and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0027] This embodiment also provides an amino acid-based soft crystal shampoo, comprising the above-mentioned amino acid soft crystal composition.

[0028] Example 3 This embodiment provides an amino acid flexible crystal composition, comprising the following components: Table 3 Components of Amino Acid Soft Crystal Composition

[0029] The preparation method of the above-mentioned amino acid soft crystal composition includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose were dispersed in 54 parts of deionized water and heated to 85°C. Acrylic acid (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 80 MPa for 3 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add ceramide, sodium benzoate and amino acid solution to step (1) and stir until uniform. After cooling, the amino acid soft crystal composition is obtained.

[0030] This embodiment also provides an amino acid soft crystal shower gel, comprising the above-mentioned amino acid soft crystal composition.

[0031] Example 4 This embodiment provides an amino acid flexible crystal composition, comprising the following components: Table 4. Components of the Amino Acid Soft Crystal Composition

[0032] The preparation method of the above-mentioned amino acid soft crystal composition includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose were dispersed in 40 parts of deionized water and heated to 80°C. Acrylic (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 60 MPa for 4 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add hyaluronic acid, phenoxyethanol and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0033] This embodiment also provides an amino acid soft crystal shower gel, comprising the above-mentioned amino acid soft crystal composition.

[0034] Example 5 This embodiment provides an amino acid flexible crystal composition, comprising the following components: Table 5. Components of the Amino Acid Soft Crystal Composition

[0035] The preparation method of the above-mentioned amino acid soft crystal composition includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose were dispersed in 40 parts of deionized water and heated to 80°C. Acrylic (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 60 MPa for 4 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add hyaluronic acid, phenoxyethanol and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0036] This embodiment also provides an amino acid soft crystal shower gel, comprising the above-mentioned amino acid soft crystal composition.

[0037] Comparative Example 1 This comparative example provides an amino acid composition that differs from Example 1 only in that it uses sodium lauroyl sarcosinate instead of lauroyl alanine.

[0038] Comparative Example 2 This comparative example provides an amino acid composition that differs from Example 1 only in that sodium lauroylaminopropionate is used instead of sodium cocoylaminoalanine.

[0039] Comparative Example 3 This comparative example provides an amino acid composition that differs from Example 1 only in that the thickener consists of 0.3 parts of acrylate / C10-30 alkanol acrylate crosspolymer, 0.5 parts of sodium alginate, and 0.6 parts of hydroxyethyl cellulose.

[0040] The method for preparing the amino acid composition includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose were dispersed in 40 parts of deionized water and heated to 80°C. Acrylic (ester) crosspolymer / C10-30 alkanol acrylate, oleyl erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 60 MPa for 4 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add hyaluronic acid, phenoxyethanol and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0041] Comparative Example 4 This comparative example provides an amino acid composition that differs from Example 1 only in that the thickener consists of 0.3 parts of acrylate / C12-22 alkanol methacrylate copolymer and 1.1 parts of sodium alginate.

[0042] The method for preparing the amino acid composition includes the following steps: (1) Sodium alginate was dispersed in 40 parts of deionized water and heated to 80°C. Acrylic acid (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 60 MPa for 4 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add hyaluronic acid, phenoxyethanol and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0043] Comparative Example 5 This comparative example provides an amino acid composition that differs from Example 1 only in that the thickener consists of 0.3 parts of acrylate / C12-22 alkanol methacrylate copolymer and 1.1 parts of hydroxyethyl cellulose.

[0044] The method for preparing the amino acid composition includes the following steps: (1) Hydroxyethyl cellulose was dispersed in 40 parts of deionized water and heated to 80°C. Acrylic (ester) / C12-22 alkanol methacrylate copolymer, oleyl alcohol erucic acid ester and silachlor ammonium pyroxene were added and homogenized at 60 MPa for 4 cycles. (2) Sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine were dissolved in deionized water to obtain an amino acid solution; (3) Add hyaluronic acid, phenoxyethanol and amino acid solution to step (1) and stir until homogeneous. After cooling, the amino acid soft crystal composition is obtained.

[0045] Comparative Example 6 This comparative example provides an amino acid composition that differs from Example 1 only in that the dispersant used is 1.2 parts of oleyl erucic acid ester.

[0046] Comparative Example 7 This comparative example provides an amino acid composition that differs from Example 1 only in that the dispersant used is 1.2 parts of silachlor hydrate.

[0047] Experimental Example 1 The appearance and stability of the amino acid crystalline compositions were tested using an optical microscope (Nikon ECLIPSE Ci-L, 400× magnification) to observe the crystal morphology and quantity distribution of the amino acid compositions in Examples 1-5 and Comparative Examples 1-7. The specific method was as follows: 0.5g of each sample was placed on a glass slide and evenly spread into a thin layer approximately 0.5mm thick. After covering with a coverslip, the sample was observed under the optical microscope. Ten different fields of view were randomly selected and photographed. ImageJ image analysis software was used to count the number and size of crystal particles in each field of view (with a fixed area of ​​0.5mm × 0.5mm), and the average crystal count (number of crystals / mm²) and D50 / D90 ratio were calculated for the ten fields of view. The morphological characteristics of the crystals were also recorded. All samples were tested on the third day after preparation to ensure complete crystallization.

[0048] Each product was sealed and placed at 45℃±1℃ and RH60%±5% for 1 month. The changes in product condition were observed, and the results are shown in Table 6.

[0049] Table 6. Results of appearance and stability tests on the amino acid crystalline compositions.

[0050] Note: "Not detected (<5)" indicates that the number of crystals in this field of view is extremely small and cannot be effectively counted; the closer the particle size uniformity ratio D50 / D90 is to 1, the more concentrated and uniform the crystal particle size distribution is.

[0051] Table 6 shows that in Comparative Examples 3-5, the number of crystals per unit area decreased significantly after the thickener component was omitted or replaced. This indicates that the acrylic (ester) / C12-22 alkanol methacrylate copolymer, sodium alginate, and hydroxyethyl cellulose together constitute the "skeleton network" of crystallization. The absence of any one component cannot induce the amino acid surfactant to arrange itself into crystals in an orderly manner. In addition, Comparative Examples 3-5 showed obvious stratification after being placed at 45°C for one month, indicating that changing the thickener could not maintain the spatial network structure of the crystal matrix. The increase in temperature led to increased polymer chain segment movement, and the crystals lost their physical constraints, resulting in dissolution and precipitation.

[0052] After replacing the amino acid components in Comparative Examples 1-2, the number of crystals decreased significantly, and the crystal morphology changed from regular prismatic to fine needle-like. This indicates that lauroyl alanine plays a crystal form guiding role in the crystal growth process. Its specific molecular structure forms a eutectic with the other two amino acid salts, promoting the balanced growth of crystals in three dimensions. The fine needle-like crystal form also leads to a significant decrease in particle size uniformity. In addition, Comparative Examples 1-2 showed stratification after being placed at 45°C for one month, indicating that changing the amino acid composition causes the combined crystals to lose their thermodynamic stability, transforming them into a more stable amorphous state, thereby causing the product to lose its "flexible crystal" properties.

[0053] Although a small amount of crystals formed in Comparative Examples 6-7, the number of crystals per unit area was only 41%~45% of that in Example 1, and the particle size uniformity D50 / D90 ratio was significantly reduced. This indicates that oleyl erucic acid ester and silachlorite slurry synergistically exerted dispersion and suspension effects, and neither dispersant alone could suppress crystal aggregation and sedimentation, ultimately leading to uneven distribution. More significantly, Comparative Examples 6-7 all exhibited agglomeration and sedimentation, further demonstrating that oleyl erucic acid ester and silachlorite slurry synergistically exerted dispersion and suspension effects, maintaining product stability.

[0054] In summary, the superior performance of the amino acid soft crystal composition of the present invention stems from the synergistic cooperation of the amino acid compound, the specific ternary thickener system, and the specific binary dispersant system in the three stages of crystallization nucleation, crystal growth, and crystal stabilization, which together achieve the synergistic technical effect of "numerous crystals, regular and uniform morphology, and stable distribution".

[0055] Experimental Example 2 Cleaning power evaluation of amino acid crystalline compositions. The foaming performance of Examples 1-5 and Comparative Examples 1-2 was evaluated using a SITA foam tester, which can repeatedly evaluate the foaming performance of surfactants by automatically measuring foam volume. The test temperature was set at 25°C, tap water was used, the sample volume was 300 mL, and the sample concentration was 1.0%. The results are shown in Table 7.

[0056] Table 7. Foaming performance test results of amino acid crystallization compositions

[0057] Table 7 shows that Example 1 exhibits the highest foaming speed and maximum foam height, indicating that Example 1 has the best foaming performance and good cleaning properties. The foaming performance of Examples 2-5 is similar to that of Example 1. However, after changing the amino acid composition, Comparative Examples 1-2 show a significant decrease in both foaming speed and maximum foam height, resulting in a substantial reduction in the cleaning power of the products.

[0058] Experimental Example 3 Evaluation of the use of amino acid crystallization compositions.

[0059] Sixty volunteers aged 20-45 with healthy skin were selected, with 30 volunteers in each group. The samples to be tested (Examples 1-5 and Comparative Examples 1-7) were divided into two batches (Batch 1: Examples 1, 3, 5 + Comparative Examples 1, 3, 6; Batch 2: Examples 2, 4 + Comparative Examples 2, 4, 5, 7), and a double-blind, randomized, self-controlled design was used for testing. Six identical test areas (2cm × 2cm) were marked on the inner side of one forearm of each volunteer, with an interval of ≥1.5cm between areas. The six samples were applied to each area in a randomized order at a dosage of 2.0 mg / cm², massaged in circular motions for 30 seconds, and then rinsed with running water. The interval between two consecutive tests was at least 15 minutes to ensure that the skin condition returned to baseline. Each volunteer completed one batch of samples, and after a 24-hour interval, another batch of samples was tested using the same method. Finally, the average value of the data obtained for each sample was taken. The evaluation criteria are shown in Table 8, and the results are shown in Table 9.

[0060] Table 8 Product User Experience Evaluation Criteria

[0061] Table 9 Results of User Experience with the Amino Acid Composition

[0062] Table 9 shows that the scores of the examples are significantly better than those of the comparative examples, indicating that this application achieves a comprehensive effect of "high cleaning power + rapid bead melting + long-lasting moisturizing" through the synergistic effect of specific amino acid complexes, ternary thickeners and binary dispersants. Among them, the bead melting speed (9.1) and smoothness (8.9) of Example 1 are significantly better than those of Comparative Examples 6-7 (approximately 5.0), indicating that the uniformly distributed fine prisms melt upon contact, while the agglomerated large crystal particles have a noticeable scratching sensation. The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An amino acid soft crystal composition, characterized in that, It includes the following components by weight: 15-25 parts amino acid compound, 0.5-2 parts thickener, 0.5-2 parts dispersant, 2-10 parts humectant, 0.05-1 part preservative, and 70-90 parts deionized water; The amino acid complex is composed of sodium cocoylaminoalanine, potassium cocoylglycinate and lauroylalanine in a mass ratio of (3-5):(2-5):(10-15). The thickener is composed of an acrylic (ester) / C12-22 alkanol methacrylate copolymer, sodium alginate, and hydroxyethyl cellulose in a mass ratio of (0.1-0.5):(0.2-0.7):(0.3-0.8). The dispersant is composed of oleyl erucic acid ester and silachlorite hydropyroxene in a mass ratio of (0.3-1):(0.2-1).

2. The amino acid flexible crystal composition according to claim 1, characterized in that, The amino acid complex is composed of sodium cocoylaminoalanine, potassium cocoylglycinate, and lauroylalanine in a mass ratio of (3-4):(2-4):(11-13).

3. The amino acid flexible crystal composition according to claim 1, characterized in that, The thickener is composed of acrylate / C12-22 alkanol methacrylate copolymer, sodium alginate and hydroxyethyl cellulose in a mass ratio of (0.2-0.4):(0.3-0.6):(0.5-0.6).

4. The amino acid flexible crystal composition according to claim 1, characterized in that, The dispersant is composed of oleyl erucic acid ester and silachlorite hydropyroxene in a mass ratio of (0.5-0.8):(0.5-0.7).

5. The amino acid flexible crystal composition according to claim 1, characterized in that, The moisturizer is selected from one or more of hyaluronic acid, ceramide, butylene glycol, propylene glycol, polyethylene glycol, urea, sodium lactate, and sodium polyaspartate.

6. The amino acid flexible crystal composition according to claim 1, characterized in that, The preservative is selected from one or more of phenoxyethanol, methylparaben, ethylparaben, propylparaben, sodium benzoate, potassium sorbate, and iodopropynylcarbamate.

7. A method for preparing the amino acid soft crystal composition according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Sodium alginate and hydroxyethyl cellulose are dispersed in 2 / 5-3 / 5 deionized water and heated. Acrylic (ester) / C12-22 alkanol methacrylate copolymer and dispersant are added and homogenized. (2) The amino acid complex was dissolved in the remaining deionized water to obtain an amino acid solution; (3) Add humectant, preservative and amino acid solution to step (1), stir well, and cool to obtain the product.

8. The preparation method according to claim 7, characterized in that, The heating temperature in step (1) is 75-85℃.

9. The preparation method according to claim 7, characterized in that, The homogenization pressure in step (1) is 40-80 MPa, and the cycle is repeated 3-5 times.

10. An amino acid-based soft crystal cosmetic, characterized in that, The amino acid flexible crystal composition according to any one of claims 1-6 or the amino acid flexible crystal composition prepared by the preparation method according to any one of claims 7-9.

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