A seven-dimensional soothing dual cleansing and care foam intimate care lotion and a method of preparing the same

Abstract

This invention discloses a seven-dimensional soothing and dual-cleansing foam feminine wash and its preparation method, belonging to the field of feminine feminine care technology. The wash consists of a "seven-dimensional soothing" system composed of seven active ingredients, including ectoine, α-mannan, and Centella asiatica extract, combined with a "dual-cleansing" system composed of amino acid surfactants. Its pH value (25℃) is 5.00±0.05, viscosity (25℃) is 300~700 mPa·s, foam half-life is ≥120 seconds, bubble diameter is ≤0.3mm, it can withstand 300 consecutive pumping cycles without clogging, and shows no stratification or sedimentation after three freeze-thaw cycles. Its preparation employs a unique "phase-separated premixing-low-temperature confluence" process, preheating and solubilizing oil-soluble components such as bisabolol, followed by low-temperature confluence after cooling, and supplemented with a glycerin-assisted hydration process, effectively avoiding the risks of product turbidity and pump head clogging. It is suitable for daily cleaning and care of the female vulva.

Description

Technical Field

[0001] This invention belongs to the technical field of feminine intimate care products, specifically relating to a foam-type intimate care wash with seven-dimensional synergistic soothing and dual gentle cleansing effects and its preparation method. Background Technology

[0002] The skin of the female vulva is thin with a dense distribution of nerve endings, making it sensitive to external stimuli. Daily life presents multiple challenges, including menstruation, exercise, and seasonal changes, easily leading to dryness, tightness, redness, and other discomforts. Modern women's needs for intimate care products have evolved from basic cleansing to a comprehensive demand for "gentle cleansing + multi-dimensional soothing + environmental adaptation + pleasurable experience." However, existing products generally suffer from the following technical deficiencies: (1) Limited scope of relief. Most commercially available products use single or simple compounded soothing ingredients, which can only address a specific dimension of discomfort and cannot simultaneously deal with complex problems such as dryness, tightness, and redness, resulting in a poor consumer experience.

[0003] (2) The pH is not compatible with the vulvar environment. Healthy vulvar skin is slightly acidic (pH 4.5-5.5), which differs from the vaginal environment. Most existing products are designed with the latter pH (3.8-4.5), and long-term use for vulvar cleaning can easily disrupt its natural acid-base balance, leading to dry and tight skin.

[0004] (3) Poor product stability and user experience. Oil-soluble ingredients such as bisabolol, added to enhance the skincare effect, are difficult to disperse stably in the aqueous phase and are prone to precipitation under conventional processes, resulting in product turbidity and clogging of the mousse pump head. At the same time, large molecular moisturizers such as sodium hyaluronate are prone to agglomeration when added directly, exacerbating pump head clogging and coarse foam problems.

[0005] In summary, there is an urgent need for a feminine wash that can simultaneously address multi-dimensional soothing, precise pH matching, and process stability. Summary of the Invention

[0006] The purpose of this invention is to provide a seven-dimensional soothing and dual-care foaming feminine wash and its preparation method. This invention, through a specific combination of components and a unique low-temperature phase separation preparation process, aims to simultaneously solve the aforementioned challenges of multi-dimensional soothing, pH compatibility, and product stability.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A seven-dimensional soothing dual-cleansing foam feminine wash, characterized in that its raw material composition, by weight percentage, is as shown in Table 1: Functional category component weight percentage (%) Double-cleansing surfactant sodium methyl cocoyl taurate 2.00~3.50 Cocamidopropyl betaine 0.80–1.50 pH buffer system with lactic acid 0.07–0.13 Sodium lactate 0.50–1.10 Seven-Dimensional Soothing System: Ectoin 0.40–0.80 α-Mannan 0.10–0.30 Sodium hyaluronate (molecular weight 100,000 Da) 0.03~0.10 Dipotassium glycyrrhizate 0.10–0.30 Panthenol 0.30–0.80 Centella asiatica extract 0.10–0.40 Bisabolol 0.03–0.10 Solubilizer and preservative: p-hydroxyacetophenone 0.10–0.25 PEG-40 hydrogenated castor oil 0.80~1.50 Caprylyl glycol 0.30–0.70 Ethylhexylglycerin 0.15–0.40 1,2-Hexanediol 0.30–0.70 Chelating and moisturizing EDTA disodium 0.10–0.25 Glycerin 2.00–5.00 Solvent, deionized water balance Note: Due to the inability to upload the table, the following correspondence is used. The pH value of the washing solution is 5.00±0.05 (25℃); the washing solution is fragrance-free, and after standing, it does not separate into layers, precipitate, or produce flocculent matter. It is a uniform, semi-transparent, clear liquid with a slight blue opalescence, and no visible particles or free oil droplets are observed when examined under light; the viscosity at 25℃ is 300~700 mPa·s.

[0008] Terminology Definition The "Seven-Dimensional Synergistic Soothing System" described in this invention refers to a care system formed by the synergistic effects of seven ingredients—ectoine, α-mannan, sodium hyaluronate, dipotassium glycyrrhizate, panthenol, centella asiatica extract, and bisabolol—acting synergistically in seven dimensions. The functions of the seven ingredients are as follows: (1) Ectoin: Maintains the skin barrier and enhances tolerance to external stimuli; (2) α-Mannan: As a prebiotic, it helps maintain the balance of the skin's surface microecology; (3) Centella Asiatica extract: for dry and rough skin, and to maintain the good condition of the stratum corneum; (4) Dipotassium glycyrrhizate: effectively relieves skin redness, burning and other discomforts; (5) Panthenol: Deeply hydrates and enhances the skin's own barrier resilience; (6) Bisabolol: Reduces skin sensitivity and soothes stinging and itching; (7) Sodium hyaluronate (molecular weight 100,000 Da): forms a water-locking film on the skin surface to achieve long-lasting moisturization.

[0009] The seven ingredients work synergistically to provide comprehensive care from seven dimensions: barrier maintenance, microecological nutrition, surface hydration, redness relief, deep moisturization, dryness care, and sensitivity care. The effect is far superior to that of a single ingredient or a simple combination.

[0010] The "dual cleaning and protection system" described in this invention refers to a surfactant system composed of sodium methylcocoyl taurate and cocamidopropyl betaine. Sodium methylcocoyl taurate is an amino acid-type anionic surfactant, while cocamidopropyl betaine is an amphoteric surfactant. The two are compounded in a specific weight ratio (1.8–3.5):1, achieving moderate cleaning power while also possessing extremely low degreasing power and excellent foam stability, leaving skin feeling neither tight nor dry after washing.

[0011] The "medium-low temperature phase-separated premixing process" described in this invention refers to a process in which fat-soluble components, poorly soluble components, and active ingredients are premixed into independent phases outside the main pot, with the temperature of each phase controlled not to exceed 50°C, before being sequentially introduced into the main pot. This process effectively avoids the problems of turbidity caused by the separation of fat-soluble components, agglomeration of large-molecule humectants clogging the pump head, and high-temperature deactivation of heat-sensitive active ingredients.

[0012] The "glycerol-assisted hydration process" described in this invention refers to a process in which sodium hyaluronate powder is pre-dispersed with glycerol, then pure water is added and allowed to hydrate at room temperature until it is fully swollen. This process utilizes the excellent wetting and encapsulating properties of glycerol on sodium hyaluronate powder to prevent it from agglomerating upon direct contact with water, ensuring complete hydration and the absence of white-core particles.

[0013] The term "fragrance-free" as used in this invention refers to the absence of added synthetic fragrances or plant essential oils used in daily chemical products. Trace amounts of natural odorous substances naturally present in the raw materials themselves are not included in this definition.

[0014] Seven-dimensional synergistic soothing system Seven active ingredients work synergistically to form a multi-dimensional skincare network. The mechanisms of action of each ingredient are as defined in the terminology definition. The combination of the seven ingredients produces a synergistic effect, which can simultaneously address multiple coexisting skin discomforts such as dryness, tightness, redness, and stinging. The effect is far superior to that of a single ingredient or a simple combination (see Comparative Example 1 for data comparison).

[0015] Sodium methyl cocoyl taurate is an amino acid-type anionic surfactant, and cocamidopropyl betaine is an amphoteric surfactant. When the two are compounded in a specific weight ratio (1.8-3.5):1, the foam is fine and dense, with moderate degreasing power. While providing effective cleaning, it greatly reduces damage to the sebum film, leaving the skin moisturized and not tight after washing.

[0016] Lactic acid and sodium lactate form a buffer pair with a weight ratio of (0.08~0.16):1, stabilizing the pH of the system at 5.00±0.05, which is highly compatible with the physiological environment of a healthy vulva (pH 4.5~5.5), ensuring that the vulva does not feel dry or tight during long-term care.

[0017] Caprylyl glycol, ethylhexylglycerin, 1,2-hexanediol and p-hydroxyacetophenone work synergistically to form a polyol synergistic preservative system. No additional phenoxyethanol or paraben-based traditional preservatives are added, which greatly reduces the potential risk of irritation and is suitable for the daily care needs of delicate skin.

[0018] Stable clarification system By using a medium-low temperature phase separation premixing and glycerin-assisted hydration process, the fat-soluble components are fully solubilized and the sodium hyaluronate is fully swollen, resulting in a product with a uniform, semi-transparent, stable micelle emulsion, which, combined with the mousse pump head, provides continuous foaming.

[0019] This invention also provides a method for preparing the washing solution, the core of which is "phase-separated premixing and low-temperature confluence," adhering to the principle of "medium and low temperature priority," and setting dual temperature red lines: ≤38℃ for the surfactant dissolution stage in the main pot, and ≤30℃ for the active ingredient addition stage. Only the solubilizing premixed phase can be briefly heated to 45-50℃ (it can only be added to the pot after cooling). The specific steps are as follows: (1) Preparation of solubilized premixed phase (D1): Mix PEG-40 hydrogenated castor oil with bisabolol, heat to 45-50℃ and stir until completely transparent, cool to a temperature difference of ≤5℃ with the main pot liquid and set aside. The cooled D1 solubilized phase must be added to the main pot within 4 hours; if turbidity occurs after cooling, it needs to be reheated to 45-50℃ to dissolve and then cooled before use.

[0020] (2) Preparation of p-hydroxyacetophenone pre-solution (D2): p-hydroxyacetophenone was dissolved in 4% of deionized water by heating to 40-50°C and then cooled for later use.

[0021] (3) Preparation of hyaluronic acid pre-dissolved slurry (D3): Disperse sodium hyaluronate powder evenly with a portion of glycerol, wherein the weight ratio of glycerol used for pre-dispersion to sodium hyaluronate is ≥5:1; add 5% of the total water volume of deionized water, stir at room temperature and let stand for hydration for ≥45 minutes until completely swollen into a particle-free and transparent slurry, stirring at low speed for 1 minute every 15 minutes during hydration, and then pass through a 200-mesh sieve for later use.

[0022] (4) Preparation of mannan presol (D4): Dissolve α-mannan in 3% of total water by heating to 40-50°C, pass through a 200-mesh sieve, and cool for later use.

[0023] (5) Preparation of active ingredient pre-solution (D5): At room temperature (≤30℃), ectoine, panthenol, dipotassium glycyrrhizate and Centella asiatica extract are dissolved in 5% of the total water volume of deionized water. The solution is prepared and used immediately, and then poured into the main pot within 1 hour.

[0024] (6) Feeding the main pot: Add 60% of the total water volume of deionized water to the main pot, then add disodium EDTA, sodium lactate and the remaining glycerin in sequence. After stirring and dissolving, control the temperature at 35-38℃. Slowly add sodium methyl cocoyl taurate and cocamidopropyl betaine below the liquid surface. After complete dissolution, immediately cool down to ≤30℃.

[0025] (7) Low-temperature homogenization: In the order of D3, D5, D4, D2 and D1, each premixed phase is added to the main pot in sequence. After each phase is added, it is stirred at medium speed to achieve uniformity. When adding D1, it is necessary to ensure that the temperature difference between the material and the main pot is ≤5℃. Stir until the system presents a uniform, semi-transparent, stable micelle blue light, without any white turbidity or abnormal opalescence caused by precipitation or demulsification.

[0026] (8) Adding and adjusting the pH: Add octyl glycol, ethylhexylglycerin, and 1,2-hexanediol in sequence and stir well. Dilute lactic acid 15 times with deionized water and slowly add it dropwise to 2 / 3 of the liquid surface in the stirrer. Fine-tune the pH to 5.00±0.05 under constant temperature of 25℃. If the pH is lower than 4.95, adjust it with sodium lactate solution. After adding water and adjusting the volume, retest.

[0027] (9) Post-processing and filling: The material is filtered through a two-stage filter consisting of a 200-mesh filter cloth and a 1.2μm polyethersulfone filter element. It is then slowly stirred (100rpm) for 15 minutes under a vacuum of -0.08 to -0.09MPa. After standing and buffering for 30 minutes, it is filled into a mousse pump head bottle equipped with a 300-mesh double-layer foaming net in a clean environment.

[0028] The initial water volume of each pre-dissolved phase and the main pot accounts for 77% of the total water volume, and the remaining water volume is used for lactic acid dilution, volume adjustment and pH adjustment.

[0029] Beneficial effects Compared with the prior art, the outstanding advantages of the present invention are: (1) Seven-dimensional synergy for comprehensive relief: Seven active ingredients work synergistically from seven dimensions to comprehensively care for various discomforts such as dryness, tightness, and redness, significantly improving post-wash comfort; (2) Precise pH and environmental compatibility: The pH value is stable at 5.00±0.05, which precisely matches the weakly acidic environment of a healthy vulva and does not cause dryness or irritation with long-term use; (3) Double cleansing and gentle cleansing: The unique amino acid compound system effectively cleanses without damaging the sebum film, leaving the skin moisturized and not tight after washing; (4) Microecological friendly: α-Mannan, as a prebiotic, helps maintain the microecological balance of the private parts; (5) Innovative process, stable and smooth: The original "phase-separation premixing-low temperature convergence" process effectively avoids the risk of product turbidity and pump head blockage, and the product foam is delicate and the foaming is continuous. Detailed Implementation The present invention will be further described in detail below through specific embodiments and comparative examples, but the present invention is not limited to these embodiments.

[0030] A seven-dimensional soothing dual-cleansing foam feminine wash, composed of the ingredients shown in Table 2 by weight percentage: Functional category component weight percentage (%) Double-cleansing surfactant sodium methyl cocoyl taurate 2.80 Cocamidopropyl betaine 1.20 pH buffer system with 0.11% lactic acid Sodium lactate 0.85 Seven-Dimensional Soothing System Ectoin 0.60 α-Mannan 0.18 Sodium hyaluronate (100,000 Da) 0.06 Dipotassium glycyrrhizate 0.20 Panthenol 0.50 Centella asiatica extract 0.20 Bisabolol 0.06 Solubilizer and preservative: 0.15g p-hydroxyacetophenone PEG-40 hydrogenated castor oil 1.10 Octyl glycol 0.50 Ethylhexylglycerin 0.25 1,2-Hexanediol 0.50 Chelating and moisturizing EDTA disodium 0.18 Glycerin 2.80 Solvent, deionized water balance The product was prepared according to the aforementioned method. The resulting product was a uniform, semi-transparent, clear liquid with a slight blue opalescence, a pH of 5.00, a viscosity of 450 mPa·s, a foam half-life of 158 seconds, and could be continuously pressed 300 times without clogging. After three freeze-thaw cycles, the material became clear and could be pressed normally.

[0031] Comparative Example 1 (without the seven-dimensional efficacy system) All seven soothing active ingredients, including ectoine and α-mannan, were removed; the rest remained the same as in Example 1. This study aimed to demonstrate the substantial contribution of the seven-dimensional synergistic soothing system to moisturizing and calming effects.

[0032] Bisabolol and p-hydroxyacetophenone were mixed directly with the main pot at room temperature without premixing, and the rest was the same as in Example 1. This was intended to demonstrate the necessity of the phase-separated premixing process for product clarity and pump head unobstructed flow.

[0033] By increasing the amount of lactic acid and correspondingly decreasing the amount of sodium lactate, the product's pH was adjusted to 4.0 (simulating the typical acidity of commercially available vaginal douches), with the rest remaining the same as in Example 1. This was intended to demonstrate the crucial impact of a pH of 5.00, precisely adapted to the slightly acidic environment of the vulva, on user comfort.

[0034] Sodium hyaluronate was added directly as a dry powder to the main pot without glycerol dispersion and hydration, and the rest was the same as in Example 1. This was intended to demonstrate the indispensable role of the glycerol-assisted hydration process in preventing agglomeration, precipitation, and pump head clogging.

[0035] Performance tests were conducted on Example 1 and Comparative Examples 1-4 using standard methods, and the results are shown in Table 3. Test Item Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, Comparative Example 4 pH value (25℃): 5.00 5.00 5.00 4.00 5.00 Uniform appearance, semi-transparent, blue light, clear, transparent, cloudy, abnormally opalescent, clear, transparent, flocculent precipitate Viscosity (mPa·s, 25℃) 450 420 — 445 — Foam half-life (s): 158, 120, 95, 132, 88 Press continuously 300 times without blockage; 82nd press results in blockage without blockage; 38th press results in blockage. Stability after 3 freeze-thaw cycles: no stratification, slight stratification, no stratification, stratification Post-wash moisturizing rate (%): +33.8 +11.6 +31.4 +29.7 +24.1 Volunteer comfort level: 4.8 (3.1), 4.1 (3.4), 3.6 (3.6) Table 3 Note: All performance tests were conducted at a constant temperature of 25℃ and a constant humidity of 55%RH. Moisturizing rate was measured using a skin moisture meter to determine the change in moisture 30 minutes after washing. Volunteer comfort was assessed using a subjective rating of 1-5 points from 30 female subjects after a single use, with rating dimensions including post-wash dryness, tightness, redness relief, and itching relief. "—" indicates that viscosity could not be accurately measured due to turbidity or flocculent sedimentation of the product, making viscosity testing impossible.

[0036] Results Analysis (1) Comparison of Example 1 and Comparative Example 1: The moisturizing rate jumped from +11.6% to +33.8%, and the comfort level increased from 3.1 points to 4.8 points. This intuitively demonstrates the significant synergistic effect of the seven-dimensional synergistic system, proving that the combination of the seven active ingredients is not a simple addition, but rather produces a substantial synergistic care effect.

[0037] (2) Comparison between Example 1 and Comparative Example 2: The lack of phase separation and solubilization led to abnormal white opalescence, freeze-thaw instability, and blockage on the 82nd time. In contrast, Example 1 showed stable and uniform micelle blue light and all indicators were normal, which strongly proves that the phase separation premixing process is the core technical means to ensure stable product clarification and smooth foaming of the pump head.

[0038] (3) Comparison between Example 1 and Comparative Example 3: After the pH deviated to 4.0, the comfort level dropped sharply from 4.8 to 3.4. Although pH 4.0 is highly acidic, it deviates from the original weakly acidic environment of the vulva, and long-term use can easily disrupt the microecological balance; while the pH 5.0 of this invention achieves a precise match between gentle cleaning and microecological maintenance, which fully proves the scientific nature and necessity of the pH setting of this invention.

[0039] (4) Comparison between Example 1 and Comparative Example 4: Direct feeding of hyaluronic acid dry powder caused flocculent precipitation, difficulty in filtration, and blockage on the 38th time. On the contrary, it verified that the glycerin-assisted hydration process is an indispensable process to prevent the aggregation of macromolecular moisturizers, ensure product clarification, and ensure smooth pump head.

Claims

1. A seven-dimensional soothing dual-cleansing foam feminine wash, characterized in that, By weight percentage, the raw material composition is as follows: sodium methyl cocoyl taurate 2.00%–3.50%, cocamidopropyl betaine 0.80%–1.50%, lactic acid 0.07%–0.13%, sodium lactate 0.50%–1.10%, ectoine 0.40%–0.80%, α-mannan 0.10%–0.30%, and sodium hyaluronate (molecular weight 100,000 Da). 0.03%–0.10%, dipotassium glycyrrhizate 0.10%–0.30%, panthenol 0.30%–0.80%, Centella asiatica extract 0.10%–0.40%, bisabolol 0.03%–0.10%, p-hydroxyacetophenone 0.10%–0.25%, disodium EDTA 0.10%–0.25%, PEG-40 hydrogenated castor oil 0.80%–1.50%, caprylyl glycol 0.30%–0.70%, ethylhexyl glycol The washing solution contains 0.15%–0.40% oil, 0.30%–0.70% 1,2-hexanediol, 2.00%–5.00% glycerol, with the balance being deionized water; the pH value of the washing solution is 5.00±0.05 (25℃); the washing solution is fragrance-free, and after standing, it does not separate into layers, precipitate, or produce flocculent matter, but is a uniform, semi-transparent, clear liquid with a slight blue opalescence, and no visible particles or free oil droplets are observed when examined under light; the viscosity at 25℃ is 300–700 mPa·s.

2. The washing solution according to claim (1), characterized in that, The weight ratio of lactic acid to sodium lactate is (0.08–0.16):

1.

3. The washing solution according to claim (1), characterized in that, The sodium hyaluronate is pre-dispersed with glycerol, and the weight ratio of glycerol used for pre-dispersion to sodium hyaluronate is ≥5:

1.

4. The washing solution according to claim (1), characterized in that, The total weight percentage of the seven active ingredients—ecodyne, α-mannan, sodium hyaluronate, dipotassium glycyrrhizate, panthenol, Centella asiatica extract, and bisabolol—is 1.50%–2.80%, forming a seven-dimensional soothing system. The weight ratio of sodium methyl cocoyl taurate to cocamidopropyl betaine is (1.8–3.5):1, forming a dual cleansing system.

5. The washing solution according to claim (1), characterized in that, The washing solution is filled into a gas-liquid suspension pump head equipped with a 300-mesh double-layer foaming net. It can be continuously pressed 300 times at room temperature and pressure without clogging. After standing for 24 hours, the first pump runs smoothly without drying out, and the foam half-life is ≥120 seconds and the bubble diameter is ≤0.3mm.

6. A method for preparing a washing solution as described in any one of claims (1) to (4), characterized in that, The entire process adheres to the principle of prioritizing medium and low temperatures, and sets dual temperature red lines: ≤38℃ during the main pot surfactant dissolution stage and ≤30℃ during the active material addition stage. Only the solubilized premixed phase can be heated to 45-50℃ for a short time. Includes the following steps: (6-1) Mix PEG-40 hydrogenated castor oil with bisabolol, heat to 45-50℃ and stir until transparent, cool to a temperature difference of ≤5℃ with the main pot liquid and set aside to obtain phase D1; the cooled phase D1 solubilized phase must be added to the main pot within 4 hours; if turbidity occurs after cooling, it needs to be reheated to 45-50℃ to dissolve and then cooled before use; (6-2) Dissolve p-hydroxyacetophenone in a mixture of p-hydroxyacetophenone and some deionized water at 40-50°C, and then cool to obtain phase D2; (6-3) Disperse sodium hyaluronate with a portion of glycerol, wherein the weight ratio of glycerol to sodium hyaluronate is ≥5:1, add a portion of deionized water, let stand at room temperature for ≥45 minutes to hydrate, stirring at low speed for 1 minute every 15 minutes during this period, until a clear slurry without particles is obtained, and pass through a 200-mesh sieve to obtain phase D3. (6-4) Dissolve α-mannan in a mixture of deionized water at 40-50°C, pass through a 200-mesh sieve, and cool to obtain phase D4; (6-5) At room temperature (≤30℃), ectoine, panthenol, dipotassium glycyrrhizate and Centella asiatica extract are dissolved in a portion of deionized water to obtain phase D5. It should be prepared and used immediately and poured into the main pot within 1 hour. (6-6) Add the remaining deionized water, disodium EDTA, sodium lactate and the remaining glycerin to the main pot. After dissolving, control the temperature at 35-38℃. Slowly add sodium methyl cocoyl taurate and cocamidopropyl betaine below the liquid surface. After completely dissolving, cool down to ≤30℃. (6-7) Add the materials to the main pot in the order of D3, D5, D4, D2 and D1, and stir until they are uniform after each addition. When adding D1, ensure that the temperature difference between the material and the main pot is ≤5℃. Stir until the system shows a uniform, semi-transparent, stable micelle blue light, without any white turbidity or abnormal opalescence caused by precipitation or demulsification. (6-8) Add octyl glycol, ethylhexylglycerin, and 1,2-hexanediol in sequence and stir well; dilute lactic acid with deionized water 15 times and slowly add it dropwise to 2 / 3 of the liquid surface in the stirrer; finely adjust the pH to 5.00±0.05 under constant temperature of 25℃; if the pH is lower than 4.95, adjust it with sodium lactate solution; after adding water to make up the volume, retest. (6-9) The material is filtered through a 200-mesh filter cloth and a 1.2μm polyethersulfone filter element. It is then slowly stirred (100rpm) for 15 minutes under a vacuum of -0.08 to -0.09MPa to degas the material. After standing for 30 minutes, it is filled into a mousse pump head equipped with a 300-mesh double-layer foaming net.

7. The preparation method according to claim (6), characterized in that, In step (6-6), sodium methyl cocoyl taurate and cocamidopropyl betaine are slowly added below the liquid surface, and the temperature of the main pot is controlled at 35-38℃. After complete dissolution, the temperature is immediately reduced to ≤30℃. In step (6-8), the diluted lactic acid solution is slowly added dropwise at 2 / 3 below the liquid surface of the stirring paddle, and the pH is finely adjusted to 5.00±0.05 at a constant temperature of 25℃.

8. The preparation method according to claim (6), characterized in that, After the material described in steps (6-9) is degassed under vacuum, it is allowed to stand for 30 minutes.

9. The preparation method according to claim (6), characterized in that, When adding D1 in steps (6-7), the temperature difference between the material and the main pot should be ≤5℃. Stir until the system exhibits a uniform, semi-transparent, stable micelle blue light, without any white turbidity or abnormal opalescence.

10. A feminine intimate care foam product, characterized in that, The washing liquid comprises any one of claims (1) to (5) and is packaged in a gas-liquid suspension pump head with a 300-mesh double-layer foaming net; when the washing liquid is sprayed out through the pump head, the foam half-life is ≥120 seconds and the bubble diameter is ≤0.3mm; after the washing liquid is subjected to three freeze-thaw cycles at -5℃ to 40℃, there is no stratification or sedimentation, the first pump is smooth and there is no dryness, and there is no blockage after 300 consecutive presses.