A mild stable povidone iodine private part bacteriostatic care liquid and a preparation method thereof

Abstract

The present application relates to the technical field of private part care bacteriostatic agent, and discloses a mild and stable povidone iodine private part bacteriostatic care liquid and a preparation method thereof.The care liquid comprises a copolymerized povidone VA64-iodine complex, a surfactant, a moisturizing agent, a conditioning agent, a thickening agent, a buffer, a preservative and water, the effective iodine content is 0.05-0.20 g / L, and the pH is 3.8-5.5.The present application improves the stability of effective iodine and reduces irritation through mechanical grinding complexing, low-temperature cold compounding and buffer adjustment, and is suitable for daily bacteriostatic care of private parts.

Description

Technical Field

[0001] This invention relates to antibacterial preparations for feminine hygiene, and more particularly to a mild and stable povidone-iodine feminine hygiene antibacterial care solution and its preparation method. Background Technology

[0002] Povidone-iodine is widely used for skin, mucous membrane, and wound disinfection due to its broad-spectrum antibacterial activity, rapid action, and low likelihood of developing resistance. Unlike conventional disinfection applications, intimate area care products need to simultaneously ensure cleanliness, antibacterial properties, gentleness on mucous membranes, pH compatibility, and storage stability. Because povidone-iodine exists in a dynamic balance between bound and free iodine in the aqueous phase, and in complex systems containing multiple surfactants, humectants, and conditioning components, the effective iodine content is easily affected by pH, micellar distribution, organic matter consumption, and storage conditions, thus impacting antibacterial efficacy and user experience.

[0003] Existing technology CN108451903A discloses a povidone-iodine solution, which uses povidone-iodine, phosphate buffer, potassium iodate, glycerin, aloe polysaccharide zinc, and sodium citrate to improve the stability and long-lasting bactericidal effect of the povidone-iodine solution, and is mainly aimed at piglet bathing, wound protection, and livestock and poultry disinfection. Although this solution focuses on the stability of povidone-iodine, it still uses ordinary povidone-iodine as the effective iodine source and relies on film-forming or protective components such as aloe polysaccharide zinc. The system design does not focus on low irritation, low effective iodine, gentle cleaning with multiple surfactants, and mucosal pH adaptation in daily genital care.

[0004] Existing technology CN112315974A discloses a stability-enhanced povidone-iodine solution, which is a system composed of povidone-iodine, sodium dihydrogen phosphate, disodium hydrogen phosphate dodecahydrate, potassium iodate, sodium dodecyl sulfate, and purified water, with the pH controlled at 5.20-5.30 to maintain the effective iodine content and bactericidal efficacy. This solution mainly improves the pH and effective iodine stability of ordinary povidone-iodine solutions through phosphate buffering, potassium iodate, and sodium dodecyl sulfate. However, its formulation leans towards a disinfectant system, lacking a mild surfactant combination and a moisturizing mucosal conditioning system for intimate area care. It also fails to address the issue of how to compensate for the release of low-concentration effective iodine after continuous consumption by organic load.

[0005] Therefore, it is still necessary to provide a povidone-iodine antibacterial care solution suitable for daily feminine hygiene, which can have antibacterial effect, mucosal gentleness, pH compatibility and storage stability at a low effective iodine content, and further improve the continuous supply of effective iodine under complex care solution systems and organic load conditions. Summary of the Invention

[0006] To address the issues of insufficient effective iodine stability, high irritation of free iodine, and insufficient pH compatibility in the complex surfactant system of feminine hygiene solutions, this application provides a mild and stable povidone-iodine feminine antibacterial hygiene solution and its preparation method.

[0007] In a first aspect, the present invention provides a mild and stable povidone-iodine antibacterial care solution for intimate areas. Based on the total mass of the care solution, the solution comprises the following components: 0.10%-0.25% copovidone VA64-iodine complex, 2.0%-10.0% surfactant, 1.0%-10.0% moisturizer, 0.05%-3.0% conditioning agent, 0.005%-0.30% thickener, 0.05%-1.0% buffer solution, 0.10%-1.0% preservative, and the balance being water; the effective iodine content of the care solution is 0.05-0.20 g / L, and the pH is 3.8-5.5.

[0008] The copolyvinylpyrrolidone VA64-iodine complex provides carbonyl complexation sites and steric hindrance to polymer chains for iodine, enabling iodine to maintain a relatively stable complexed / dispersed state in aqueous phases and surfactant micelle systems. Limiting the effective iodine content to 0.05-0.20 g / L is beneficial for maintaining the inhibitory effect on Escherichia coli, Staphylococcus aureus, and Candida albicans under relatively low irritation conditions.

[0009] The copovidone VA64-iodine complex is obtained by copovidone VA64, iodine, and water through light-protected mechanical grinding and complexation. Based on a total mass of 100% for copovidone VA64, iodine, and water, the amount of copovidone VA64 is 87.0%-91.8%, the amount of iodine is 8.0%-12.0%, and the amount of water is 0.2%-2.0%; preferably, the amount of copovidone VA64 is 88.5%-90.5%, the amount of iodine is 9.0%-10.5%, and the amount of water is 0.3%-1.0%.

[0010] In a preferred embodiment, the preparation method of the copovidone VA64-iodine complex includes: adding copovidone VA64, iodine, and water to a closed mechanical grinding device for grinding under light-protected conditions; controlling the material temperature during grinding at 15-30°C, preferably 20-25°C; grinding time at 30-180 min, preferably 30-90 min; and obtaining the copovidone VA64-iodine complex after grinding. Mechanical grinding and complexation can reduce the introduction of organic solvents, lower the risk of residue, and improve the uniformity of iodine dispersion in copovidone VA64.

[0011] More preferably, the copovidone VA64-iodine complex is a gradient-bound copovidone VA64-iodine complex. Based on the total mass of the gradient-bound copovidone VA64-iodine complex being 100%, the amount of copovidone VA64 is 87.0%-91.8%, the amount of iodine is 8.0%-12.0%, and the amount of water is 0.2%-2.0%. The gradient-bound copovidone VA64-iodine complex is prepared by the following method: copovidone VA64 and water are mixed, and 70%-90% of the total iodine is added. The mixture is then mechanically ground under light-protected and cooled conditions, with the material temperature controlled at 15-30℃, for 30-120 minutes to obtain the first-stage iodine loading. The first-stage iodine loading is then matured under light-protected and sealed conditions for 6-24 hours to obtain the deeply bound iodine loading. The remaining iodine is then added, and the mixture is mixed under low-shear conditions for 5-30 minutes, and then matured further under light-protected conditions for 1-6 hours to obtain the gradient-bound copovidone VA64-iodine complex.

[0012] The aforementioned gradient-bound copolyvinylpyrrolidone VA64-iodine complex was prepared through a staged iodine loading and staged ripening process, resulting in some iodine forming a relatively stable bound state and another portion forming a relatively easily exchangeable bound state. When the rapidly exchangeable iodine in the nursing solution is consumed by the organic load, the relatively easily exchangeable bound iodine can participate in the dynamic equilibrium and replenish the exchangeable iodine in the aqueous phase, thereby improving the iodine compensation capacity under continuous organic load conditions.

[0013] The surfactants include lauryl glucoside, cocamidopropyl betaine, fatty alcohol polyoxyethylene ether AEO-9, and PEG-7 glyceryl cocoate. This combination of surfactants forms a mild cleaning and micellar solubilizing system, reducing irritation caused by the transient release of localized free iodine and improving rinsing performance.

[0014] The moisturizers include glycerin and propylene glycol. Glycerin and propylene glycol improve the feeling of moisture after application and help maintain the homogeneity of the liquid system.

[0015] The conditioning agents include one or more of the following: D-panthenol, inulin, α-glucan oligosaccharides, seaweed polysaccharides, natural aloe vera extract, Lactobacillus fermentation products, Lactobacillus lysates, or Lactobacillus post-biotics. These components are used to improve the daily care experience and local microenvironment compatibility.

[0016] The thickeners include sodium hyaluronate and carbomer. Sodium hyaluronate provides moisturizing and adhesive properties, while carbomer provides appropriate viscosity, giving the treatment solution good spreadability and retention.

[0017] The buffer solution includes citrate-sodium citrate buffer and / or lactate-sodium lactate buffer. Maintaining the pH of the care solution at 3.8-5.5 using the buffer solution helps balance pH compatibility for feminine hygiene and the storage stability of available iodine. Preferably, the pH of the feminine care solution is 3.8-5.2, and the pH of the male care solution is 5.2-5.5.

[0018] Secondly, the present invention provides a method for preparing the nursing solution, comprising the following steps:

[0019] 1) Add sodium hyaluronate to water and stir at room temperature until the sodium hyaluronate is completely dissolved to obtain sodium hyaluronate stock solution;

[0020] 2) Add water and surfactant to the mixing tank and stir for 15-30 minutes at 150-200 rpm and 20-30℃ to obtain an aqueous phase system;

[0021] 3) Control the temperature of the aqueous system to be no higher than 30°C, add the copovidone VA64-iodine complex and stir for 10-30 minutes, then add the humectant, conditioning agent and the sodium hyaluronate stock solution to obtain an iodine-containing mixture;

[0022] 4) Add preservative to the iodine-containing mixture and stir for 10-35 minutes at 80-120 rpm and 20-35℃ to obtain the liquid to be adjusted;

[0023] 5) Adjust the pH of the solution to be adjusted to 3.8-5.5 using a buffer solution, let it stand for 10-20 minutes, filter it, and fill and seal it under light-protected conditions to obtain the nursing solution.

[0024] The above preparation method employs low-temperature cold preparation and light-protected operation to avoid the adverse effects of traditional heating emulsification on the stability of effective iodine. Pre-preparing sodium hyaluronate into a stock solution reduces clumping; adding the copovidone VA64-iodine complex at a temperature not exceeding 30°C helps reduce iodine precipitation or uneven color caused by localized high concentrations of iodine; and through subsequent pH fine-tuning and filtration filling, a uniform, stable, and convenient daily care solution can be obtained.

[0025] The beneficial effects of this invention include:

[0026] This invention uses copovidone VA64-iodine complex as an effective iodine source, and combines it with a mild surfactant and a low-temperature cold compounding process to improve the stability of effective iodine in complex aqueous systems.

[0027] This invention controls the effective iodine content at 0.05-0.20 g / L, and reduces local irritation through micellar solubilization, moisturizing conditioning, and pH buffering, so that the care solution can balance antibacterial efficacy and gentleness for daily care.

[0028] This invention allows for pH adjustment according to different usage scenarios, creating products suitable for women or men, which helps meet the pH compatibility requirements of different intimate care scenarios.

[0029] This invention is prepared and filled under light-protected and low-temperature conditions, without introducing an organic solvent complexation step, which is beneficial for industrial scale-up and product quality control. Detailed Implementation

[0030] The following examples are used to illustrate the present invention, but are not intended to limit the scope of protection of the present invention. Unless otherwise stated, all percentages below are mass percentages.

[0031] The raw materials used in this embodiment are as follows:

[0032] Copovidone VA64: Pharmaceutical grade, CAS number 25086-89-9, brand name Kollidon ® VA 64, with a mass ratio of N-vinylpyrrolidone to vinyl acetate of 60:40 and a K value of 25-31, is derived from BASF SE.

[0033] Lauryl glucoside APG 1214: active ingredient content not less than 50%, free fatty alcohol content not more than 1.0%, viscosity at 40℃ not less than 2000 mPa·s, sourced from Yangzhou Chenhua New Materials Co., Ltd.

[0034] Cocamidopropyl Betaine: Brand Name: Dehyton ® PK 45, with an active ingredient content of 44%-46%, is derived from BASFSE.

[0035] Fatty alcohol polyoxyethylene ether AEO-9: HLB value is 12-13.

[0036] PEG-7 glyceryl cocoate: brand name Cetiol ® HE comes from BASF SE.

[0037] Carbopol: brand name ® The viscosity of the 980 NF, 0.5% water dispersion system is 40,000-60,000 mPa·s, sourced from Lubrizol Advanced Materials, Inc.

[0038] Sodium hyaluronate: average molecular weight 200,000-400,000 Da, reference brand Hybloom TM HA-TLM 20-40 is from Bloomage Biotechnology Co., Ltd.

[0039] Inulin: Average degree of polymerization not less than 10.

[0040] Natural Aloe Extract: An aqueous extract derived from the leaves of Aloe barbadensis Miller. Preparation method: Fresh Aloe barbadensis leaves were collected, washed, and the leaf skin and yellow sap were removed. The transparent pulp was collected and crushed. Purified water was added at a mass ratio of 1:3 (transparent pulp to purified water). The mixture was stirred and extracted at 50°C for 1 hour. After filtration, the filtrate was concentrated under reduced pressure at a temperature not exceeding 50°C until the solid content was 20 wt%, yielding the natural aloe extract.

[0041] Seaweed polysaccharides: Fucoidan derived from brown algae, with a fucoidan mass fraction of not less than 85%, a sulfate group content of not less than 20%, and an average molecular weight of 10-100 kDa.

[0042] Lactobacillus post-biotic: Post-biotic raw material obtained by inactivating and drying Lactobacillus plantarum fermentation product, with no detectable live bacteria and a solid content of not less than 90%.

[0043] Ordinary povidone-iodine: pharmaceutical grade, CAS number 25655-41-8, effective iodine content 10.0wt%.

[0044] The preservative is composed of phenoxyethanol and ethylhexylglycerin in a mass ratio of 9:1.

[0045] Example 1

[0046] A mild and stable povidone-iodine feminine hygiene wash comprises the following components by weight: 1.50 kg of copovidone VA64-iodine complex, 25.00 kg of lauryl glucoside APG 1214, 20.00 kg of cocamidopropyl betaine, 5.00 kg of fatty alcohol polyoxyethylene ether AEO-9, 5.00 kg of PEG-7 glyceryl cocoate, 30.00 kg of glycerin, 20.00 kg of propylene glycol, 1.00 kg of carbomer, 0.20 kg of sodium hyaluronate, 2.00 kg of D-panthenol, 5.00 kg of inulin, 2.00 kg of α-glucan oligosaccharide, 3.00 kg of natural aloe vera extract, 3.00 kg of citrate-sodium citrate buffer, 2.00 kg of lactate-sodium lactate buffer, 4.00 kg of preservative, and 871.30 kg of purified water, totaling 1000.00 kg.

[0047] The preparation method is as follows:

[0048] 1) Add sodium hyaluronate to 2.00 kg of purified water and stir at 25°C for 30 min until the sodium hyaluronate is completely dissolved to obtain sodium hyaluronate stock solution;

[0049] 2) Add the remaining purified water to a sterilized stainless steel mixing tank, turn on the stirrer and control the speed at 180 rpm, and add lauryl glucoside APG 1214, cocamidopropyl betaine, fatty alcohol polyoxyethylene ether AEO-9, PEG-7 glyceryl cocoate, glycerol, propylene glycol and carbomer in sequence. Stir at 25°C for 20 min to obtain a transparent and homogeneous aqueous phase system.

[0050] 3) Control the temperature of the aqueous system to 25℃, add copovidone VA64-iodine complex in the dark, stir for 15 min, then add D-panthenol, inulin, α-glucan oligosaccharide, natural aloe vera extract and sodium hyaluronate stock solution in sequence, stirring for 5 min after each addition to obtain an iodine-containing mixture.

[0051] 4) Add preservative to the iodine-containing mixture and stir at 100 rpm and 25°C for 10 minutes to obtain the liquid to be adjusted;

[0052] 5) Add 3.00 kg of pre-prepared citrate-sodium citrate buffer solution with pH 4.5 and 2.00 kg of lactate-sodium lactate buffer solution with pH 4.5 to the solution to be adjusted. Continue stirring at 100 rpm and 25°C for 5 min. The pH of the solution is measured to be 4.5. Let it stand for 15 min. Filter the solution through a 150-mesh filter and fill it into a clean, sealed container under light-protected conditions to obtain a mild and stable povidone-iodine feminine hygiene antibacterial care solution.

[0053] Preparation method of copovidone VA64-iodine complex: Under light-protected conditions, 89.5 kg of copovidone VA64, 10.0 kg of iodine, and 0.5 kg of purified water were weighed and added to a high-energy mechanical grinding device. The mixture was ground at 20°C for 30 min to obtain the copovidone VA64-iodine complex. The effective iodine content of the obtained copovidone VA64-iodine complex was determined to be 9.9 wt%.

[0054] Preparation of citric acid-sodium citrate buffer solution: At 25°C, place a 10% citric acid aqueous solution in a stirred container, stir at 150 rpm, and slowly add a 10% sodium citrate aqueous solution. During the addition process, continuously monitor the pH with a pH meter. When the pH of the mixture reaches 4.5, stop adding the solution and continue stirring for 5 minutes.

[0055] Preparation of lactate-sodium lactate buffer solution: At 25°C, place a 10% (w / w) aqueous solution of lactate in a stirred container, stir at 150 rpm, and slowly add a 10% (w / w) aqueous solution of sodium lactate. During the addition process, continuously monitor the pH with a pH meter. When the pH of the mixture reaches 4.5, stop adding the solution and continue stirring for 5 minutes.

[0056] Example 2

[0057] The male-friendly and stable povidone-iodine genital antibacterial care solution is formulated as follows: 1.30 kg of copovidone VA64-iodine complex, 20.00 kg of lauryl glucoside APG 1214, 25.00 kg of cocamidopropyl betaine, 6.00 kg of fatty alcohol polyoxyethylene ether AEO-9, 6.00 kg of PEG-7 glyceryl cocoate, 25.00 kg of glycerin, 25.00 kg of propylene glycol, 0.80 kg of carbomer, 0.15 kg of sodium hyaluronate, 2.00 kg of D-panthenol, 4.00 kg of inulin, 3.00 kg of seaweed polysaccharide, 2.00 kg of lactobacillus postbiotic, 2.00 kg of citrate-sodium citrate buffer, 1.00 kg of lactate-sodium lactate buffer, 4.00 kg of preservative, and 872.75 kg of purified water, totaling 1000.00 kg.

[0058] The preparation method is as follows:

[0059] 1) Add sodium hyaluronate to 2.00 kg of purified water and stir at 25°C for 30 min until the sodium hyaluronate is completely dissolved to obtain sodium hyaluronate stock solution;

[0060] 2) Add the remaining purified water to a sterilized stainless steel mixing tank, turn on the stirrer and control the speed at 180 rpm, and add lauryl glucoside APG 1214, cocamidopropyl betaine, fatty alcohol polyoxyethylene ether AEO-9, PEG-7 glyceryl cocoate, glycerol, propylene glycol and carbomer in sequence. Stir at 25°C for 20 min to obtain a transparent and homogeneous aqueous phase system.

[0061] 3) Control the temperature of the aqueous system to 25℃, add copovidone VA64-iodine complex in the dark, stir for 15 min, then add D-panthenol, inulin, seaweed polysaccharide, lactobacillus post-genetic agent and sodium hyaluronate stock solution in sequence, stirring for 5 min after each addition to obtain iodine-containing mixture;

[0062] 4) Add preservative to the iodine-containing mixture and stir at 100 rpm and 25°C for 10 minutes to obtain the liquid to be adjusted;

[0063] 5) Add 2.00 kg of pre-prepared citrate-sodium citrate buffer solution with pH 5.5 and 1.00 kg of lactate-sodium lactate buffer solution with pH 5.5 to the solution to be adjusted. Continue stirring at 100 rpm and 25°C for 5 min. The pH of the solution is measured to be 5.5. Let it stand for 15 min. Filter the solution through a 150-mesh filter and fill it into a clean, sealed container under light-protected conditions to obtain a mild and stable povidone-iodine antibacterial care solution for male genitals.

[0064] Preparation method of copovidone VA64-iodine complex: Under light-protected conditions, 89.5 kg of copovidone VA64, 10.0 kg of iodine, and 0.5 kg of purified water were weighed and added to a high-energy mechanical grinding device. The mixture was ground at 20°C for 30 min to obtain the copovidone VA64-iodine complex. The effective iodine content of the obtained copovidone VA64-iodine complex was determined to be 9.9 wt%.

[0065] Preparation of citric acid-sodium citrate buffer: At 25°C, place a 10% citric acid aqueous solution in a stirred container and stir at 150 rpm. Slowly add a 10% sodium citrate aqueous solution. During the addition process, continuously monitor the pH with a pH meter. Stop adding when the pH of the mixture reaches 5.5, and continue stirring for 5 minutes.

[0066] Preparation of lactate-sodium lactate buffer solution: At 25°C, place a 10% (w / w) aqueous solution of lactate in a stirred container and stir at 150 rpm. Slowly add a 10% (w / w) aqueous solution of sodium lactate. During the addition process, continuously monitor the pH with a pH meter. Stop adding when the pH of the mixture reaches 5.5, and continue stirring for 5 minutes.

[0067] Example 3

[0068] A general-purpose, mild, and stable povidone-iodine antibacterial care solution for intimate areas, comprising the following components by weight: 1.70 kg of copovidone VA64-iodine complex, 30.00 kg of lauryl glucoside APG 1214, 20.00 kg of cocamidopropyl betaine, and 0.9 kg of fatty alcohol polyoxyethylene ether AEO-9. 8.00 kg of PEG-7 glyceryl cocoate, 40.00 kg of glycerin, 30.00 kg of propylene glycol, 1.20 kg of carbomer, 0.25 kg of sodium hyaluronate, 3.00 kg of D-panthenol, 5.00 kg of inulin, 3.00 kg of α-glucan oligosaccharide, 3.00 kg of seaweed polysaccharide, 3.00 kg of natural aloe vera extract, 2.50 kg of citrate-sodium citrate buffer, 1.50 kg of lactate-sodium lactate buffer, 5.00 kg of preservative, and 834.85 kg of purified water, totaling 1000.00 kg.

[0069] The preparation method is as follows:

[0070] 1) Add sodium hyaluronate to 2.00 kg of purified water and stir at 25°C for 30 min until the sodium hyaluronate is completely dissolved to obtain sodium hyaluronate stock solution;

[0071] 2) Add the remaining purified water to a sterilized stainless steel mixing tank, turn on the stirrer and control the speed at 180 rpm, and add lauryl glucoside APG 1214, cocamidopropyl betaine, fatty alcohol polyoxyethylene ether AEO-9, PEG-7 glyceryl cocoate, glycerol, propylene glycol and carbomer in sequence. Stir at 25°C for 20 min to obtain a transparent and homogeneous aqueous phase system.

[0072] 3) Control the temperature of the aqueous system to 25℃, add copovidone VA64-iodine complex in the dark, stir for 15 min, then add D-panthenol, inulin, α-glucan oligosaccharide, seaweed polysaccharide, natural aloe vera extract and sodium hyaluronate stock solution in sequence, stirring for 5 min after each addition to obtain an iodine-containing mixture.

[0073] 4) Add preservative to the iodine-containing mixture and stir at 100 rpm and 25°C for 10 minutes to obtain the liquid to be adjusted;

[0074] 5) Add 2.50 kg of pre-prepared citrate-sodium citrate buffer solution with pH 5.0 and 1.50 kg of lactate-sodium lactate buffer solution with pH 5.0 to the solution to be adjusted. Continue stirring at 100 rpm and 25°C for 5 min. The pH of the solution is measured to be 5.0. Let it stand for 15 min. Filter the solution through a 150-mesh filter and fill it into a clean, sealed container under light-protected conditions to obtain a general-purpose, mild, and stable povidone-iodine antibacterial care solution for private parts.

[0075] Preparation method of copovidone VA64-iodine complex: Under light-protected conditions, 89.5 kg of copovidone VA64, 10.0 kg of iodine, and 0.5 kg of purified water were weighed and added to a high-energy mechanical grinding device. The mixture was ground at 20°C for 30 min to obtain the copovidone VA64-iodine complex. The effective iodine content of the obtained copovidone VA64-iodine complex was determined to be 9.9 wt%.

[0076] Preparation of citric acid-sodium citrate buffer solution: At 25°C, place a 10% citric acid aqueous solution in a stirred container, stir at 150 rpm, and slowly add a 10% sodium citrate aqueous solution. During the addition process, continuously monitor the pH with a pH meter. When the pH of the mixture reaches 5.0, stop adding the solution and continue stirring for 5 minutes.

[0077] Preparation of lactate-sodium lactate buffer solution: At 25°C, place a 10% (w / w) aqueous solution of lactate in a stirred container, stir at 150 rpm, and slowly add a 10% (w / w) aqueous solution of sodium lactate. During the addition process, continuously monitor the pH with a pH meter. When the pH of the mixture reaches 5.0, stop adding the solution and continue stirring for 5 minutes.

[0078] Example 4

[0079] A mild and stable povidone-iodine feminine hygiene wash comprises the following components by weight: 1.50 kg of gradient-bound copovidone VA64-iodine complex, 25.00 kg of lauryl glucoside APG 1214, 20.00 kg of cocamidopropyl betaine, 5.00 kg of fatty alcohol polyoxyethylene ether AEO-9, 5.00 kg of PEG-7 glyceryl cocoate, 30.00 kg of glycerin, 20.00 kg of propylene glycol, 1.00 kg of carbomer, 0.20 kg of sodium hyaluronate, 2.00 kg of D-panthenol, 5.00 kg of inulin, 2.00 kg of α-glucan oligosaccharide, 3.00 kg of natural aloe vera extract, 3.00 kg of citrate-sodium citrate buffer, 2.00 kg of lactate-sodium lactate buffer, 4.00 kg of preservative, and 871.30 kg of purified water, totaling 1000.00 kg.

[0080] The preparation method is as follows:

[0081] 1) Add sodium hyaluronate to 2.00 kg of purified water and stir at 25°C for 30 min until the sodium hyaluronate is completely dissolved to obtain sodium hyaluronate stock solution;

[0082] 2) Add the remaining purified water to a sterilized stainless steel mixing tank, turn on the stirrer and control the speed at 180 rpm, and add lauryl glucoside APG 1214, cocamidopropyl betaine, fatty alcohol polyoxyethylene ether AEO-9, PEG-7 glyceryl cocoate, glycerol, propylene glycol and carbomer in sequence. Stir at 25°C for 20 min to obtain a transparent and homogeneous aqueous phase system.

[0083] 3) Control the temperature of the aqueous system to 25℃, add the gradient-bound copovidone VA64-iodine complex in the dark, stir for 15 min, and then add D-panthenol, inulin, α-glucan oligosaccharide, natural aloe vera extract and sodium hyaluronate stock solution in sequence. Stir for 5 min after each addition to obtain an iodine-containing mixture.

[0084] 4) Add preservative to the iodine-containing mixture and stir at 100 rpm and 25°C for 10 minutes to obtain the liquid to be adjusted;

[0085] 5) Add 3.00 kg of pre-prepared citrate-sodium citrate buffer solution with pH 4.5 and 2.00 kg of lactate-sodium lactate buffer solution with pH 4.5 to the solution to be adjusted. Continue stirring at 100 rpm and 25°C for 5 min. The pH of the solution is measured to be 4.5. Let it stand for 15 min. Filter the solution through a 150-mesh filter and fill it into a clean, sealed container under light-protected conditions to obtain a mild and stable povidone-iodine feminine hygiene solution with a self-compensating iodine reservoir.

[0086] The preparation method of gradient-bound copolyvinylpyrrolidone VA64-iodine complex is as follows:

[0087] 1) First stage iodine loading: Under light-protected conditions, weigh 89.5 kg of copovidone VA64 and 0.5 kg of purified water, mix them evenly, add 8.0 kg of iodine, and place them in a closed high-energy mechanical grinding equipment with a circulating cooling device for grinding; during the grinding process, control the material temperature at 20-25℃ and grind for 45 min to ensure that the iodine added in the first stage is in full contact with copovidone VA64, thus obtaining the first stage iodine-loaded material;

[0088] 2) First stage curing: The first stage iodine loading material was transferred to a light-proof and sealed container and cured at 25°C for 12 hours to allow the iodine distributed on the surface and near-surface region of VA64 during the grinding process to be further redistributed into the interior of the polymer, resulting in a deeply bound iodine loading material.

[0089] 3) Second stage iodine loading: Add the remaining 2.0 kg of iodine to the deeply bound iodine loading material, transfer it to a closed low-shear mixing device, and mix for 15 min at 25℃ and 60 rpm to make the iodine added in the second stage form a relatively easily exchangeable binding state, thus obtaining a dual-bound iodine loading material.

[0090] 4) Second-stage curing: The dual-bound iodine-supported material was further cured at 25°C under light-proof and sealed conditions for 2 hours. This allowed the iodine added in the second stage to maintain a relatively easily exchangeable state while forming a stable bond with VA64, resulting in a gradient-bound copovidone VA64-iodine complex. The effective iodine content of the obtained gradient-bound copovidone VA64-iodine complex was determined to be 9.9 wt%.

[0091] The aforementioned gradient-bound copolyvinylpyrrolidone VA64-iodine complex was prepared using a two-stage iodine loading and staged ripening method. The first stage employed higher mechanical energy input and a longer ripening time, which was beneficial for forming a relatively stable deep-bound iodine library; the second stage employed lower mechanical energy input and a shorter ripening time, which was beneficial for forming a relatively easily exchangeable compensated-bound iodine library.

[0092] When the obtained gradient-bound copovidone VA64-iodine complex is added to the nursing solution, the relatively easily exchangeable iodine component is used to maintain the initial free iodine level. When free iodine is consumed by organic load during use, the compensating bound iodine can preferentially release into the aqueous phase through dynamic equilibrium. Subsequently, the relatively stable bound iodine gradually participates in the dynamic equilibrium, further replenishing the exchangeable iodine in the system. This helps to reduce the excessive release of initial free iodine and improve the effective iodine compensation capacity under continuous organic load conditions.

[0093] Preparation of citric acid-sodium citrate buffer: At 25°C, place a 10% citric acid aqueous solution in a stirred container, stir at 150 rpm, and slowly add a 10% sodium citrate aqueous solution. During the addition process, continuously monitor the pH with a pH meter. When the pH of the mixture reaches 4.5, stop adding the solution and continue stirring for 5 minutes.

[0094] Preparation of lactate-sodium lactate buffer solution: At 25°C, place a 10% (w / w) aqueous solution of lactate in a stirred container, stir at 150 rpm, and slowly add a 10% (w / w) aqueous solution of sodium lactate. During the addition process, continuously monitor the pH with a pH meter. When the pH of the mixture reaches 4.5, stop adding the solution and continue stirring for 5 minutes.

[0095] Comparative Example 1

[0096] A feminine antibacterial care solution is basically the same as that in Example 1, except that: instead of using copovidone VA64-iodine complex as an effective iodine source, pharmaceutical-grade ordinary povidone iodine is used as an effective iodine source.

[0097] Weigh the following components by weight: 1.50 kg of ordinary povidone-iodine, 25.00 kg of lauryl glucoside APG 1214, 20.00 kg of cocamidopropyl betaine, 5.00 kg of fatty alcohol polyoxyethylene ether AEO-9, 5.00 kg of PEG-7 glyceryl cocoate, 30.00 kg of glycerol, 20.00 kg of propylene glycol, 1.00 kg of carbomer, 0.20 kg of sodium hyaluronate, 2.00 kg of D-panthenol, 5.00 kg of inulin, 2.00 kg of α-glucan oligosaccharide, 3.00 kg of natural aloe vera extract, 3.00 kg of citrate-sodium citrate buffer, 2.00 kg of lactate-sodium lactate buffer, 4.00 kg of preservative, and 871.30 kg of purified water, totaling 1000.00 kg.

[0098] The preparation method is the same as in Example 1, except that in step 3), the 1.50 kg copovidone VA64-iodine complex used in Example 1 is replaced with 1.50 kg of ordinary povidone iodine with an effective iodine content of 10.0 wt%. The other raw materials, dosages and preparation conditions are the same as in Example 1.

[0099] Test Example 1

[0100] Multiple vaginal mucosal stimulation tests

[0101] The test sample was the mild and stable povidone-iodine antibacterial care solution for private parts prepared in Examples 1-4.

[0102] The test was conducted according to the repeated vaginal mucosal irritation test method in WS / T 10009-2023 "Test Methods for Disinfection Products".

[0103] Fifteen healthy, early-adult, common-grade female New Zealand rabbits, weighing 2.0-2.5 kg, were selected. Before the experiment, the vaginal openings of the animals were examined to confirm the absence of abnormal discharge, congestion, edema, or other damage. The 15 animals were randomly divided into four groups: Example 1, Example 2, Example 3, Example 4, and a control group, with three animals in each group.

[0104] During the experiment, an approximately 8cm blunt-tipped flexible tube was connected to a 2mL syringe. The animal was positioned supine and its vaginal opening exposed. The tube was moistened with the appropriate test solution and gently inserted 4-5cm into the vagina, with 2mL of the test solution slowly injected. The control group received the same treatment with an equal volume of physiological saline. Exposure was repeated every 24 hours for 5 consecutive days.

[0105] Animals were euthanized 24 hours after the last exposure. The intact vagina was removed and longitudinally incised for visual inspection to check for obvious congestion, edema, or other signs of infection. The tissue was then fixed in 10% neutral buffered formalin solution for at least 24 hours. Tissue sections were prepared from three sites, one at each end and one in the center of the vagina, and subjected to hematoxylin and eosin (HE) staining for pathological examination.

[0106] The vaginal mucosal irritation response was scored based on four indicators: epithelial tissue damage, leukocyte infiltration, vascular congestion, and edema. The sum of the scores from nine observation sites across three animals in each group was divided by nine to obtain the average score for the group's vaginal mucosal irritation response. The irritation index was calculated using the following formula:

[0107] Stimulation index = Average score of the test group - Average score of the control group.

[0108] A stimulus index less than 1 indicates no stimulus response, 1-4 indicates a very mild stimulus response, 5-8 indicates a mild stimulus response, 9-12 indicates a moderate stimulus response, and >12 indicates a severe stimulus response. The test results are shown in Table 1.

[0109] Table 1 Results of repeated vaginal mucosal stimulation tests

[0110]

[0111] As shown in Table 1, the vaginal mucosal irritation indices for Examples 1-4 were 0.33, 0.45, 0.33, and 0.33, respectively, all less than 1, indicating no irritation. Histopathological examination revealed no obvious epithelial damage, severe inflammatory cell infiltration, significant vascular congestion, or edema.

[0112] The above results indicate that, while maintaining the effective antibacterial effect of iodine, the present invention, by controlling a low effective iodine content and combining it with mild surfactants, moisturizing and conditioning components and an organic acid buffer system, makes the resulting care solution have good mucosal gentleness and is suitable for daily care of the intimate area.

[0113] Test Example 2

[0114] Antibacterial efficacy test

[0115] The test samples were mild and stable povidone-iodine feminine hygiene solution prepared in Examples 1-4. The tests were conducted according to the quantitative suspension antibacterial test method in WS / T650-2019 "Evaluation Methods for Antibacterial and Bacteriostatic Effects".

[0116] The test strains were: Escherichia coli 8099; Staphylococcus aureus ATCC 6538; and Candida albicans ATCC 10231. All of the above test strains were commercially available.

[0117] Take fresh 24-hour cultures of each test bacterium, wash with 0.03 mol / L phosphate buffer (pH 7.2-7.4), and prepare a solution with a concentration of 5.0 × 10⁻⁶. 5 -4.5×10 6 CFU / mL bacterial suspension.

[0118] Add 5.0 mL of the original test sample solution to a sterile test tube and equilibrate at 20±1℃ for 5 min. Then add 0.1 mL of the test bacterial suspension, mix quickly, and start timing. After 2 min, inoculate 1.0 mL of the sample and bacterial suspension mixture into a Petri dish, with two parallel Petri dishes for each sample. Perform the same procedure using PBS instead of the test sample as a positive control. Use the same batch of PBS and culture medium as negative controls.

[0119] Escherichia coli and Staphylococcus aureus were cultured on nutrient agar medium at 36±1℃ for 48 h; Candida albicans was cultured on Sabouraud agar medium at 36±1℃ for 72 h. The experiment was independently repeated three times, and the colony count was recorded and the average value was calculated.

[0120] The antibacterial rate is calculated using the following formula:

[0121] Antibacterial rate / % = (A0 - A1) / A0 × 100%

[0122] In the formula: A0 is the average recovered bacterial count in the positive control group, CFU / mL; A1 is the average recovered bacterial count in the experimental group, CFU / mL.

[0123] The test results are shown in Table 2.

[0124] Table 2 Results of antibacterial efficacy test

[0125]

[0126] Negative controls showed no bacterial growth.

[0127] As shown in Table 2, after 2 minutes of action, Examples 1-3 all achieved an inhibition rate of over 99.90% against Escherichia coli, Staphylococcus aureus, and Candida albicans, demonstrating a strong antibacterial effect.

[0128] In Example 2, the amount of copovidone VA64-iodine complex added was relatively low, but it still maintained an inhibition rate of over 99.90% against the three test bacteria. In Example 3, the amount of copovidone VA64-iodine complex added was relatively high, further improving the inhibition rate against the three test bacteria. These results indicate that within the effective iodine content range defined in this invention, the obtained care solution can maintain a stable antibacterial effect within a short period of action. Example 4 used a gradient-bound copovidone VA64-iodine complex as the effective iodine source, and its inhibition rates against Escherichia coli, Staphylococcus aureus, and Candida albicans were 99.97%, 99.96%, and 99.94%, respectively, at the same level as Example 1. These results demonstrate that Example 4, by changing the binding state and release mode of iodine, did not reduce the initial antibacterial performance of the care solution.

[0129] Test Example 3

[0130] Accelerated storage stability testing

[0131] The test samples were the nursing solutions prepared in Examples 1-4 and Comparative Example 1.

[0132] Each test sample was placed into a light-proof, sealed container of the same material as the actual product, with three parallel samples in each group. The samples were stored in a constant temperature incubator at 37±2℃ for 90 days in the dark. The effective iodine content was measured at 0, 30, 60 and 90 days of storage, and the pH was measured at 0 and 90 days.

[0133] The determination of effective iodine content shall be performed by sodium thiosulfate titration method in WS / T 10009-2023 "Test Methods for Disinfection Products".

[0134] Accurately measure 50.0 mL of thoroughly mixed test sample and place it in an iodine flask. Add 5 drops of acetic acid and titrate with a standardized 0.01 mol / L sodium thiosulfate solution. Shake while titrating, and when the sample color turns pale yellow, add 10 drops of 5 g / L starch indicator solution. Continue titrating until the blue color just disappears. Perform a blank test simultaneously.

[0135] Each sample was measured in triplicate, and the average value was taken.

[0136] The effective iodine content is calculated according to the following formula:

[0137] ρ = c × V × 0.1269 × 1000 / V0

[0138] In the formula: ρ is the effective iodine content, g / L; c is the actual concentration of sodium thiosulfate titrant, mol / L; V is the volume of sodium thiosulfate titrant consumed after blank correction, mL; V0 is the volume of the test sample, mL.

[0139] The rate of decrease in effective iodine content is calculated using the following formula:

[0140] The rate of decrease in effective iodine content / % = (C0 - C) 90 ) / C0×100%

[0141] In the formula: C0 is the effective iodine content at storage 0 days; C 90 This represents the effective iodine content after 90 days of storage.

[0142] pH was measured using a pH meter calibrated with a standard buffer solution at 25±1℃. Each sample was measured in triplicate, and the average value was taken.

[0143] The test results are shown in Table 3.

[0144] Table 3. Accelerated Storage Stability Test Results

[0145]

[0146] As shown in Table 3, the effective iodine content reduction rates of Examples 1-4 after 90 days of storage at 37°C in the dark were 6.71%, 6.20%, 5.36%, and 4.70%, respectively, all below 10%. Among them, the effective iodine reduction rate of Example 4 was lower than that of Example 1, which prepared the copovidone VA64-iodine complex using a one-time mechanical grinding method.

[0147] The basic formulations, initial effective iodine content, and pH of the nursing solutions in Examples 1 and 4 are basically the same. The main difference lies in the preparation method of the copovidone VA64-iodine complex. Example 4, through a first-stage high-energy iodine loading and prolonged curing, followed by a second-stage low-energy iodine loading and shorter curing, forms a gradient-bound iodine library. Its 90-day effective iodine reduction rate decreased from 6.71% in Example 1 to 4.70%, indicating that staged iodine loading is beneficial for further improving the long-term storage stability of effective iodine.

[0148] Comparative Example 1 used ordinary povidone-iodine as the effective iodine source, and its 90-day effective iodine reduction rate reached 25.33%, which was significantly higher than that of Examples 1-4.

[0149] Test Example 4

[0150] Continuous Organic Load Consumption Response and Self-Compensation Test

[0151] The test samples were the nursing solutions prepared in Examples 1 and 4. To compare the effects of different iodine loading methods on the iodine compensation capacity after organic loading was consumed, bovine serum albumin was used as the standardized organic loading. The test samples were subjected to three consecutive rounds of organic loading treatment, and the concentration of rapidly exchangeable iodine was measured before, after, and after recovery in each round of treatment.

[0152] The rapidly exchangeable iodine refers to the iodine component that can enter the low molecular weight filtrate under specified dilution and separation conditions, and is used to evaluate the iodine content in the nursing solution that can participate in rapid exchange and compensatory release. This test is used for relative comparison between examples and does not replace the determination of the total effective iodine content.

[0153] The method for determining rapidly exchangeable iodine is as follows:

[0154] The nursing solutions from Examples 1 and 4 were diluted 10 times with a citrate-sodium citrate buffer solution at pH 4.5 to obtain a 10-fold dilution test system. Subsequent organic load treatments were all carried out in the 10-fold dilution test system.

[0155] The obtained test system was subjected to ultrafiltration using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa, and the filtrate was collected. 1.0 mL of the filtrate was taken, and potassium iodide colorimetric solution was added to convert the rapidly exchangeable iodine in the filtrate into triiodine ions. The absorbance was measured at 352 nm, and the concentration of rapidly exchangeable iodine was calculated based on the standard curve established using iodine standard solutions. A system containing the same concentration of bovine serum albumin and buffer solution but without the test sample was used as a blank for subtraction. The standard curve was established using iodine standard solutions through the same potassium iodide colorimetric procedure.

[0156] Before the first round of organic loading treatment, the concentration of rapidly exchangeable iodine in the test system was measured and recorded as the concentration before the first round of treatment, C. 前 Subsequently, bovine serum albumin solution prepared with citrate-sodium citrate buffer at pH 4.5 was added to the test system to bring the final concentration of bovine serum albumin in the test system to 0.3% (m / v). After mixing thoroughly, the concentration of rapidly exchangeable iodine was immediately measured and recorded as C0. Then, the system was incubated at 25°C in the dark for 30 minutes, and the concentration of rapidly exchangeable iodine was measured again and recorded as C. 30 ;

[0157] After the first round of treatment, an equal amount of organic load was applied to the same test system again to complete the second round of treatment using the same method. After the second round of treatment, an equal amount of organic load was applied again to complete the third round of treatment. The C values ​​for the second and third rounds... 前 These are the rapidly exchangeable iodine concentrations measured before the addition of organic load in this round.

[0158] Three complete test systems were prepared in parallel for each test sample; each test system underwent three rounds of organic loading treatment. Ultrafiltration and detection were performed immediately after sampling at each measurement time point, and the test results were the average of the three systems. Before testing, the ultrafiltration recovery rate was verified using a known concentration of iodine standard solution; a recovery rate of 90%-110% was used for sample detection.

[0159] The iodine compensation recovery rate for each round of treatment is calculated using the following formula:

[0160] Iodine compensation recovery rate / % = (C 30 -C0) / (C 前 -C0)×100%

[0161] In the formula, C 前 C0 is the rapidly exchangeable iodine concentration before the organic load treatment; C0 is the rapidly exchangeable iodine concentration measured immediately after the organic load is added and mixed thoroughly .... 30 The concentration of rapidly exchangeable iodine after adding organic load and standing in the dark for 30 minutes.

[0162] Table 4 Results of continuous organic load consumption response and self-compensation test

[0163]

[0164] As shown in Table 4, before the first round of organic loading treatment, the rapidly exchangeable iodine concentrations in Examples 1 and 4 were 4.8 mg / L and 4.3 mg / L, respectively, which were at similar levels. This indicates that Example 4 did not achieve the subsequent effect by increasing the initial rapidly exchangeable iodine content.

[0165] After the first round of organic loading treatment, the concentration of rapidly exchangeable iodine in both Examples 1 and 4 decreased significantly, indicating that the organic loading could consume the rapidly exchangeable iodine in the test system. After standing in the dark for 30 minutes, the iodine compensation recovery rate of Example 1 was 48.5%; the iodine compensation recovery rate of Example 4 reached 89.7%, which was significantly higher than that of Example 1.

[0166] As the organic load increased continuously, the iodine compensation recovery rate in Example 1 gradually decreased from 48.5% to 30.8%; in Example 4, after three consecutive rounds of organic load treatment, the iodine compensation recovery rate still reached 73.1%.

[0167] The basic formulations, initial effective iodine content, and pH of the nursing solutions in Examples 1 and 4 are basically the same. The main difference lies in the preparation method of the copovidone VA64-iodine complex. The above results indicate that, compared with the copovidone VA64-iodine complex prepared by single-stage mechanical grinding, the gradient-bound copovidone VA64-iodine complex prepared in Example 4 using a staged iodine loading and staged ripening method exhibits stronger compensation and recovery capabilities after the rapidly exchangeable iodine is consumed by organic loading, and can still maintain a high iodine compensation level under continuous multi-round consumption conditions.

[0168] The above results show that Example 4 does not simply increase the initial effective iodine content, but rather changes the binding and exchange state of iodine in copovidone VA64, so that the system can be continuously replenished after the rapidly exchangeable iodine is consumed, thereby forming an organic load consumption-responsive self-compensating iodine reservoir.

[0169] Test Example 5

[0170] Physicochemical and hygiene indicator tests

[0171] The test sample was the mild and stable povidone-iodine antibacterial care solution for private parts prepared in Examples 1-4.

[0172] The effective iodine content was determined by the sodium thiosulfate titration method described in Test Example 3. Each sample was measured in triplicate, and the average value was taken.

[0173] pH was measured directly at 25±1℃ using a calibrated pH meter. Each sample was measured in triplicate, and the average value was taken.

[0174] To determine the contents of lead, mercury, and arsenic, accurately weigh 0.5 g of the mixed test sample, add nitric acid and hydrogen peroxide, and perform microwave digestion. After digestion, bring the volume to a final level with ultrapure water. Inductively coupled plasma mass spectrometry (ICP-MS) was then used to determine the contents of lead, mercury, and arsenic.

[0175] The limits of detection for each element are as follows: lead: 0.03 mg / kg; mercury: 0.003 mg / kg; arsenic: 0.03 mg / kg. Results below the limits of detection are indicated as "not detected".

[0176] For microbiological indicators, since the test sample itself has antibacterial properties, it must be neutralized before testing. Take 10 mL of the test sample and add it to 90 mL of sterile neutralizing diluent containing sodium thiosulfate, mix thoroughly to inactivate any residual available iodine. The neutralizing agent used should be verified in advance to effectively terminate the antibacterial effect of the test sample and should not have significant toxicity to the test microorganisms.

[0177] The neutralized samples were tested as follows: total bacterial count was calculated using nutrient agar medium at 36±1℃ for 48 hours; total fungal count was calculated using Sabouraud agar medium at 28±1℃ for 5 days; coliform bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, and hemolytic streptococci were detected by enrichment culture, selective culture, and necessary biochemical identification, respectively.

[0178] A blank control of the culture medium and a negative control of the neutralization solution were set up. The test results are shown in Table 5.

[0179] Table 5. Test results of physicochemical and hygienic indicators for Examples 1-4

[0180]

[0181] As shown in Table 5, the effective iodine content of Examples 1-4 is within the range of 0.05-0.20 g / L as defined in this invention; the pH values ​​are 4.50, 5.50, 5.00 and 4.50, respectively, which are consistent with the target pH values ​​of each example and are all within the range of 3.8-5.5 as defined in this invention.

[0182] In Examples 1-4, lead, mercury, and arsenic levels were all below the detection limits of their respective methods; the total bacterial count was less than 5 CFU / mL; and the total fungal count and the specific microorganisms tested were not detected. These results demonstrate that the nursing solution obtained by this invention has stable physicochemical properties and good hygienic quality.

[0183] The care solution of this invention can be produced using conventional mixing tanks, filtration equipment, and light-proof filling equipment. The preparation process does not require high-temperature emulsification or organic solvent complexation steps; the process conditions are mild and suitable for large-scale production. The resulting care solution is characterized by effective iodine stability, pH adjustability, low irritation, and good antibacterial effect, and can be used as a daily cleaning and antibacterial product for intimate areas.

Claims

1. A mild and stable povidone-iodine antibacterial care solution for intimate areas, characterized in that, The solution comprises, by weight percentage, the following components: 0.10%-0.25% copovidone VA64-iodine complex, 2.0%-10.0% surfactant, 1.0%-10.0% humectant, 0.05%-3.0% conditioning agent, 0.005%-0.30% thickener, 0.05%-1.0% buffer solution, 0.10%-1.0% preservative, and the balance being water; the effective iodine content of the solution is 0.05-0.20 g / L, and the pH is 3.8-5.

5.

2. The mild and stable povidone-iodine vaginal antibacterial care solution according to claim 1, characterized in that: The copovidone VA64-iodine complex is obtained by copovidone VA64, iodine and water through light-protected mechanical grinding and complexation, and the effective iodine content in the copovidone VA64-iodine complex is 8.0wt%-12.0wt%.

3. The mild and stable povidone-iodine antibacterial care solution for intimate areas according to claim 1, characterized in that: The copovidone VA64-iodine complex is a gradient-bound copovidone VA64-iodine complex. The gradient-bound copovidone VA64-iodine complex is prepared by the following method: copovidone VA64 and water are mixed, and 70%-90% of the total iodine content is added. The mixture is then mechanically ground under light-protected and cooled conditions to obtain a first-stage iodine loading. This first-stage iodine loading is then matured under light-protected and sealed conditions for 6-24 hours to obtain a deeply bound iodine loading. The remaining iodine is then added, and the mixture is mixed under low-shear conditions for 5-30 minutes, and matured further under light-protected conditions for 1-6 hours to obtain the gradient-bound copovidone VA64-iodine complex.

4. The mild and stable povidone-iodine vaginal antibacterial care solution according to claim 1, characterized in that: The surfactants include lauryl glucoside, cocamidopropyl betaine, fatty alcohol polyoxyethylene ether AEO-9, and PEG-7 glyceryl cocoate; based on the total mass of the care solution, lauryl glucoside is 0.8%-4.0%, cocamidopropyl betaine is 1.0%-5.0%, fatty alcohol polyoxyethylene ether AEO-9 is 0.2%-2.0%, and PEG-7 glyceryl cocoate is 0.1%-2.0%.

5. The mild and stable povidone-iodine vaginal antibacterial care solution according to claim 1, characterized in that: The moisturizer comprises glycerin and propylene glycol; based on the total mass of the care solution, glycerin comprises 0.5%-5.0% and propylene glycol comprises 0.5%-5.0%.

6. The mild and stable povidone-iodine feminine hygiene solution according to claim 1, characterized in that: The conditioning agents include one or more of D-panthenol, inulin, α-glucan oligosaccharides, seaweed polysaccharides, natural aloe vera extract, lactobacillus fermentation products, lactobacillus lysates, or lactobacillus metabiotics.

7. The mild and stable povidone-iodine feminine hygiene solution according to claim 1, characterized in that: The thickeners include sodium hyaluronate and carbomer; the buffers include citrate-sodium citrate buffer and / or lactate-sodium lactate buffer.

8. The mild and stable povidone-iodine vaginal antibacterial care solution according to claim 1, characterized in that: When the care solution is a feminine care solution, the pH is 3.8-5.2; when the care solution is a male care solution, the pH is 5.2-5.

5.

9. A method for preparing the mild and stable povidone-iodine antibacterial care solution for intimate areas according to any one of claims 1-8, characterized in that, Includes the following steps: 1) Add sodium hyaluronate to water and stir at room temperature until the sodium hyaluronate is completely dissolved to obtain sodium hyaluronate stock solution; 2) Add water and surfactant to the mixing tank and stir at 150-200 rpm and 20-30℃ for 15-30 min to obtain an aqueous phase system; 3) Control the temperature of the aqueous system to be no higher than 30°C, add the copovidone VA64-iodine complex and stir for 10-30 minutes, then add the humectant, conditioning agent and the sodium hyaluronate stock solution to obtain an iodine-containing mixture; 4) Add preservative to the iodine-containing mixture and stir for 10-35 minutes at 80-120 rpm and 20-35℃ to obtain the liquid to be adjusted; 5) Adjust the pH of the solution to be adjusted to 3.8-5.5 using a buffer solution, let it stand for 10-20 minutes, filter it, and fill and seal it under light-protected conditions to obtain the nursing solution.

10. The method for preparing a mild and stable povidone-iodine antibacterial agent for genital use according to claim 9, characterized in that: In step 5), a 100-200 mesh filter is used for filtration; steps 1-5) are all carried out under conditions of avoiding light or low light.

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