A gynecological antibacterial gel and its preparation method

Abstract

This invention belongs to the technical field of medical gels, specifically relating to a gynecological antibacterial gel and its preparation method. The gel comprises an antibacterial phase and a probiotic phase. Through the synergistic ratio of naringin, nisin, and lauroyl arginine ethyl hydrochloride, broad-spectrum inhibition of common pathogenic bacteria is achieved. Simultaneously, the introduction of *Lactobacillus rhamnosus* metabolites and sodium hyaluronate constructs a probiotic phase, promoting probiotic colonization and the restoration of vaginal microecological balance. The gel maintains a stable pH of 4.0–4.5, exhibiting good rheological properties and retention performance. In the preparation method, each component is added stepwise, and the system temperature and stirring conditions are controlled to ensure component activity and product stability. This invention can effectively alleviate bacterial vaginosis, fungal infections, and microecological disorders, providing synergistic, safe, and gentle comprehensive care effects.

Description

Technical Field

[0001] This invention belongs to the technical field of medical gels, specifically relating to a gynecological antibacterial gel and its preparation method. Background Technology

[0002] Gynecological diseases are common health problems for women, especially vaginitis and cervicitis caused by pathogenic microorganisms. These diseases have a high incidence rate and are prone to recurrence, seriously affecting women's quality of life. With the improvement of people's health awareness and the popularization of personalized treatment concepts, safe, convenient, and highly targeted topical preparations have gradually attracted attention. In particular, gel-based preparations applied locally in the vagina have become an important research and development direction in the field of gynecological treatment due to their advantages such as good adhesion, strong controllable release, and direct action on lesions.

[0003] Currently, gynecological gels commonly found on the market are mainly divided into three categories: first, medicated gels containing antibiotics or antifungal components; second, natural antibacterial gels with traditional Chinese medicine extracts as the main ingredient; and third, functional drug-loaded gels constructed based on polymer materials. While the first type of preparation has a rapid onset of action, it easily induces drug resistance and disrupts the vaginal flora balance; the second type has complex components, and the extraction process affects stability, with a lag in the release of its effects; the third type focuses on building a sustained-release system, but often lacks targeted antibacterial components and has low antibacterial activity. Furthermore, some gels exhibit poor stability in the vagina, strong irritation, and poor user comfort, which also limits their widespread application.

[0004] Therefore, developing a gynecological gel that combines good antibacterial activity, biocompatibility, and adhesive properties is an urgent direction for promoting innovation in gynecological topical preparations and meeting women's health needs. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a gynecological antibacterial gel comprising the following components by weight percentage: naringin 0.1%–0.3%; lauroyl arginine ethyl ester hydrochloride 0.05%–0.15%; nisin 0.02%–0.08%; Lactobacillus rhamnosus metabolite powder 0.3%–0.8%; sodium hyaluronate 0.2%–0.5%; polyvinyl alcohol 1.2%–3.0%; carbomer 0. 0.5%–1.0%; Glycerin 0.5%–1.2%; Propylene glycol 0.2%–0.6%; Sodium citrate 0.05%–0.2%; Sodium lactate 0.2%–0.6%; Hydroxypropyl methylcellulose 0.1%–0.4%; Potassium sorbate 0.05%–0.2%; Phenoxyethanol 0.1%–0.25%; Disodium EDTA 0.01%–0.05%; Triethanolamine 0.1%–0.25%; Balance: Deionized water;

[0006] The mass ratio of naringin, nisin and lauroyl arginine ethyl hydrochloride is (4-6):(1-1.5):(1-2).

[0007] The mass ratio of Lactobacillus rhamnosus metabolites, sodium hyaluronate, and polyvinyl alcohol is (2-3):(1-1.5):(3-5).

[0008] The mass ratio of carbomer to triethanolamine is (2.5–4):1;

[0009] The total mass fraction of glycerol, propylene glycol and hydroxypropyl methylcellulose is 1.2% to 2.2%.

[0010] The gel has a pH of 4.0–4.5, exhibits a uniform semi-solid appearance when left to stand at 25°C, and has a shear rate of 10 s⁻¹. -1 The viscosity is 8000–14000 mPa·s, and no visible layering, precipitation or sedimentation occurs within 48 hours.

[0011] As a preferred technical solution, the naringin is obtained by pulverizing the peel of citrus fruits after low-temperature drying to a moisture content of no more than 8%. The extraction solvent is a 70% ethanol-water system with a material-to-liquid ratio of 1:10. The extraction is carried out by ultrasonic extraction at 55°C for 2 hours. The resulting extract is concentrated under reduced pressure, filtered to remove impurities, cooled to crystallize, and then filtered and dried to obtain a yellow crystalline powder.

[0012] As a preferred technical solution, the lauroyl arginine ethyl ester hydrochloride is a salt-type amphoteric compound obtained by neutralization treatment after condensation esterification reaction of lauric acid and L-arginine. The resulting product is a white or off-white crystalline powder with a drying loss of no more than 5%, a particle size D90 of less than 80 μm, and dissolves in an aqueous phase at 25°C to form a clear solution.

[0013] As a preferred technical solution, the lactic acid nisin is a peptide component derived from the liquid fermentation broth of *Streptococcus lactis*. After filtration through a 0.2 μm ceramic membrane, desalination with a strong acid resin, and concentration via reverse osmosis, it is freeze-dried to obtain a powdered solid. The molecular weight of this substance ranges from 2500 to 3500 Da, its whiteness is not less than 80%, its solubility in deionized water at 25°C is ≥10 mg / mL, and the pH of the resulting solution is 6.5 to 7.0.

[0014] As a preferred technical solution, the Lactobacillus rhamnosus metabolite is a white to pale yellow powder prepared by spray drying after the cell supernatant obtained by deep liquid fermentation is concentrated to 1 / 6 of the original volume by an ultrafiltration membrane with a molecular retention limit of 3000 Da. The powder has a solid content of not less than 90% and a water content of less than 5%.

[0015] As a preferred technical solution, the sodium hyaluronate is a medium molecular weight product produced by fermentation, with a number average molecular weight of 7 × 10⁻⁶. 4 ~1.2×10 5 Da, in its dry powder state, has a moisture content of less than 8%, and its 0.5% aqueous solution has a viscosity of 1000-1500 mPa·s at 25℃.

[0016] As a preferred technical solution, the glycerol and propylene glycol are pharmaceutical-grade liquid components, with contents of 0.5%–1.2% and 0.2%–0.6%, respectively. The glycerol has a trihydroxypropane structure and a viscosity of 1000-1500 mPa·s at 25°C, while the propylene glycol is a colorless, transparent liquid with a density of 1.036 g / cm³. 3 The two are added and mixed separately during the matrix stage, with a total amount not exceeding 1.8%; the hydroxypropyl methylcellulose is a low-viscosity white powder with a particle size controlled between 80 and 120 mesh.

[0017] This invention also provides a method for preparing the aforementioned gynecological antibacterial gel, comprising the following steps:

[0018] S1. Constructing the initial dispersed phase and adjusting the pH: Carbomer was added to deionized water at 25°C and stirred for 30-45 minutes until completely dispersed to obtain the initial dispersed phase. Triethanolamine was then added to adjust the pH to 4.1±0.1, and stirring was continued for 10 minutes.

[0019] S2. Gradually construct the gel matrix system: Add polyvinyl alcohol, sodium hyaluronate, hydroxypropyl methylcellulose, glycerol and propylene glycol in sequence. Each component is added after the previous component is completely dispersed. Stir for at least 15 minutes after each component is added. The entire matrix construction stage lasts for at least 60 minutes.

[0020] S3. Introduction of bioregulatory functional components: Nisin and Lactobacillus rhamnosus metabolites were dissolved in deionized water to prepare a 1% mass concentration solution, which was then added dropwise to the matrix system at 35°C and stirred for 25 minutes to form a uniform dispersion.

[0021] S4. Add synergistic antibacterial active ingredients: Add lauroyl arginine ethyl ester hydrochloride and naringin pre-solution, control the dropping rate to within 1.0 mL / min, maintain the system temperature not higher than 38℃, and keep the pH value stable between 4.0 and 4.3;

[0022] S5. Add auxiliary components and complete final conditioning: Add sodium lactate, sodium citrate, disodium EDTA, phenoxyethanol, and potassium sorbate, stir for 15 minutes, clarify the system, degas under vacuum at -0.09 MPa for 15 minutes, cool to room temperature, and then fill to obtain the finished product.

[0023] As a preferred technical solution, the naringin mentioned in step S4 is pre-dissolved in a 1:4 volume ratio 70% ethanol-water system at a concentration of 10 mg / mL, and slowly added dropwise to the preparation system at a volume ratio not exceeding 3%, with the dropping rate controlled at 0.5-1.0 mL / min. During the dropping process, the mixture is continuously stirred at a speed of 300 rpm. After the dropping is completed, stirring is continued for 15 minutes.

[0024] As a preferred technical solution, in step S2, polyvinyl alcohol is added before other matrix components, dissolved in an 80°C water bath for 30 minutes, cooled to below 35°C, and then sodium hyaluronate is added. After stirring for 30 minutes, hydroxypropyl methylcellulose is slowly added. During the mixing process, the pH value of the system is stable in the range of 4.2±0.1.

[0025] Beneficial effects:

[0026] This invention overcomes the limitation of unstable activity of a single antibacterial component in a low-pH vaginal environment by setting a synergistic ratio range of (4-6):(1-1.5):(1-2) for naringin, nisin, and lauroyl arginine ethyl hydrochloride. The three components exhibit complementary characteristics with different mechanisms of action under acidic conditions, effectively achieving the goal of multi-pathway intervention for microecological imbalance. Naringin, as a flavonoid component, has a membrane structure interference effect; nisin has a good perforation effect on Gram-positive bacteria; and lauroyl arginine ethyl hydrochloride, as a surfactant antibacterial agent, can achieve rapid penetration. The synergistic use of the two in a specific ratio avoids the irritation risk caused by dose superposition, ensuring biocompatibility and targeting at low doses.

[0027] Furthermore, this invention establishes a mass ratio control mechanism (2-3):(1-1.5):(3-5) among Lactobacillus rhamnosus metabolites, sodium hyaluronate, and polyvinyl alcohol. This mechanism not only maintains the moisturizing and rheological properties of the gel carrier but, more importantly, precisely regulates the osmotic pressure and sustained-release rate of the local microenvironment by adjusting the ratio of probiotic metabolites to water-retaining factors. This ratio setting enables the gradual release of probiotic signaling factors at the target site while ensuring that the gel forms a uniform coating layer locally, making it difficult to be expelled and prolonging the effective action time. It exhibits superior sustained bioregulatory capabilities compared to existing probiotic gels.

[0028] Furthermore, this invention optimizes the ratio control range of carbomer to triethanolamine (2.5–4):1, and strictly limits the total mass fraction of glycerol, propylene glycol, and hydroxypropyl methylcellulose (1.2%–2.2%) to ensure that the system achieves a shear rate of 10 s⁻¹ at 25°C. -1This invention presents a homogeneous semi-solid structure with a viscosity of 8000–14000 mPa·s, which remains free from stratification, separation, or precipitation for up to 48 hours. Compared to the viscoelastic instability or thermodynamic phase separation problems of traditional gel systems, the component synergistic region established in this invention exhibits high process controllability and physical stability in actual preparation and storage, making it more suitable for preparing gynecological care formulations with good adhesion and precise drug release. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the method flow of the present invention;

[0030] Figure 2 This is a schematic diagram of the antibacterial performance test results of the present invention;

[0031] Figure 3 This is a schematic diagram of the probiotic survival and colonization simulation test results of the present invention;

[0032] Figure 4 This is a schematic diagram of the pH buffering capacity test results of the present invention;

[0033] Figure 5 This is a schematic diagram of the slippage test results of the present invention;

[0034] Figure 6 This is a schematic diagram of the adhesion rate test results of the present invention. Detailed Implementation

[0035] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0036] Example 1

[0037] Experimental Group 1 (T1): Gel formulation and preparation using the lower limit of the parameter range:

[0038] This experimental group is an embodiment of the present invention, aiming to verify whether the described antibacterial and antimicrobial biphasic gel can still achieve good physical stability and target functional performance when the mass percentage of each major active component is taken as the lower limit of the set range. All raw materials used are pharmacopoeia or enterprise standards, and the test was conducted in a constant temperature and clean environment. The preparation steps are as follows: Figure 1 As shown, the details are as follows:

[0039] Formula composition (by weight percentage):

[0040] Naringin: 0.1%;

[0041] Lauroyl arginine ethyl ester hydrochloride: 0.05%;

[0042] Nisin: 0.02%;

[0043] Lactobacillus rhamnosus metabolite dry powder: 0.3%;

[0044] Sodium hyaluronate: 0.2%;

[0045] Polyvinyl alcohol: 1.2%;

[0046] Carbomer: 0.5%;

[0047] Glycerin: 0.5%;

[0048] Propylene glycol: 0.2%;

[0049] Sodium citrate: 0.05%;

[0050] Sodium lactate: 0.2%;

[0051] Hydroxypropyl methylcellulose: 0.1%;

[0052] Potassium sorbate: 0.05%;

[0053] Phenoxyethanol: 0.1%;

[0054] Disodium EDTA: 0.01%;

[0055] Triethanolamine: 0.1%;

[0056] Deionized water: Add to 100%.

[0057] Preparation process:

[0058] S1. Weigh 0.5% carbomer and slowly add it to deionized water at room temperature (25℃). Turn on medium speed (350 rpm) and continue stirring for 45 minutes until it is fully expanded and dispersed to form a uniform and transparent initial gel phase. Slowly add 0.1% triethanolamine to adjust the pH to 4.1±0.1 and continue stirring for 10 minutes to stabilize the system.

[0059] S2. Sequentially add 1.2% polyvinyl alcohol (pre-dissolved in an 80°C water bath for 30 minutes and cooled to below 35°C for later use), 0.2% sodium hyaluronate, 0.1% hydroxypropyl methylcellulose, 0.5% glycerin, and 0.2% propylene glycol. Stir for at least 15 minutes after each addition to ensure the system is fully swollen and mixed. The entire matrix construction phase should be maintained for a total of 60 minutes.

[0060] S3. Prepare 1% solutions of 0.02% nisin and 0.3% Lactobacillus rhamnosus metabolite powder respectively, and slowly add them dropwise in equal volumes to the above matrix system at 35°C. Stir for 25 minutes to form a transparent and uniformly dispersed system.

[0061] S4. In addition, 0.1% naringin is pre-dissolved in a 70% ethanol-water system at a volume ratio of 1:4, with the concentration controlled at 10 mg / mL and the dropping rate controlled at no more than 0.5 mL / min. At the same time, 0.05% lauroyl arginine ethyl ester hydrochloride is dissolved in deionized water. The two are added to the system one after the other, with a total dropping time of no less than 20 minutes. The temperature is maintained at ≤38℃ during the dropping process, and the pH value of the system is controlled within the range of 4.0 to 4.3.

[0062] S5. Finally, add sodium lactate (0.2%), sodium citrate (0.05%), disodium EDTA (0.01%), phenoxyethanol (0.1%), and potassium sorbate (0.05%) in sequence, and stir continuously for 15 minutes. After confirming that the system is clear in appearance, degas it under vacuum at -0.09 MPa for 15 minutes. After degassing, cool it to room temperature and fill it into the finished product to obtain the test sample of experimental group 1.

[0063] Experimental Group 2 (T2): Gel formulation and preparation using the upper limit of the parameter range:

[0064] To further verify the performance of the gynecological antibacterial gel described in this invention under the upper limit of component ratio, experimental group 2 was prepared and formulated with the upper limit of the set range of each core component, focusing on the physical stability, rheological behavior and continuous regulation ability of the gel system under high activity loading conditions.

[0065] Formula composition (by weight percentage):

[0066] Naringin: 0.3%;

[0067] Lauroyl arginine ethyl ester hydrochloride: 0.15%;

[0068] Nisin: 0.08%;

[0069] Lactobacillus rhamnosus metabolite dry powder: 0.8%;

[0070] Sodium hyaluronate: 0.5%;

[0071] Polyvinyl alcohol: 3.0%;

[0072] Carbomer: 1.0%;

[0073] Glycerin: 1.2%;

[0074] Propylene glycol: 0.6%;

[0075] Sodium citrate: 0.2%;

[0076] Sodium lactate: 0.6%;

[0077] Hydroxypropyl methylcellulose: 0.4%;

[0078] Potassium sorbate: 0.2%;

[0079] Phenoxyethanol: 0.25%;

[0080] Disodium EDTA: 0.05%;

[0081] Triethanolamine: 0.25%;

[0082] Deionized water: Add to 100%.

[0083] Preparation steps:

[0084] S1. At 25℃, 1.0% carbomer is evenly sprinkled into deionized water and stirred rapidly until it fully expands to form a colloidal solution. The stirring time is 40 minutes. 0.25% triethanolamine is slowly added dropwise to adjust the pH value. The final pH value of the system is controlled at 4.1±0.1. Stirring is continued for 10 minutes to form a transparent initial gel base.

[0085] S2. Add 3.0% polyvinyl alcohol (pre-dissolved in an 80°C water bath for 30 minutes and then cooled for later use), 0.5% sodium hyaluronate, 0.4% hydroxypropyl methylcellulose, 1.2% glycerol and 0.6% propylene glycol in sequence. Each component is added one at a time after the previous component has been completely dissolved and dispersed. Stir for at least 15 minutes at a time to ensure that the system is fully integrated. The entire matrix construction stage is maintained for a total of 80 minutes.

[0086] S3. Prepare 1% aqueous solutions of 0.08% nisin and 0.8% Lactobacillus rhamnosus metabolite powder, respectively. Slowly add these solutions to the matrix system at a constant temperature of 35℃ for at least 10 minutes. Stir the mixture for 25 minutes to obtain a stable and uniform dispersion system of microecological functional factors.

[0087] S4. Pre-dissolve 0.3% naringin in a 70% ethanol-water system at a volume ratio of 1:4, controlling the concentration to 10 mg / mL, and add it dropwise to the system at a rate not exceeding 1.0 mL / min. At the same time, add 0.15% lauroyl arginine ethyl ester hydrochloride aqueous solution. During the dropwise addition, control the system temperature not to exceed 38℃ and the pH value to be stable in the range of 4.0 to 4.3.

[0088] S5. Subsequently, add 0.6% sodium lactate, 0.2% sodium citrate, 0.05% disodium EDTA, 0.25% phenoxyethanol, and 0.2% potassium sorbate, and stir thoroughly for 15 minutes. After observing that the system is clear and free of flocculation or insoluble particles, degas at -0.09 MPa for 15 minutes, cool to room temperature, and then fill into containers to obtain the gel sample of experimental group 2.

[0089] Experimental Group 3 (T3): Gel formulation and preparation using the median value of the parameter range:

[0090] Without prioritizing extreme formulation performance, this experimental group selected the median value of the mass percentage settings for each key functional component in the technical solution of this invention as the optimal ratio for gel formulation and preparation. The aim was to explore the compatibility and synergistic effect between the microecological regulating components and the antibacterial components under reasonable concentration configurations, as well as the physical stability and operability of the system in practical application scenarios.

[0091] Formula composition (by weight percentage):

[0092] Naringin: 0.2%;

[0093] Lauroyl arginine ethyl ester hydrochloride: 0.10%;

[0094] Nisin: 0.05%;

[0095] Lactobacillus rhamnosus metabolite dry powder: 0.55%;

[0096] Sodium hyaluronate: 0.35%;

[0097] Polyvinyl alcohol: 2.1%;

[0098] Carbomer: 0.75%;

[0099] Glycerin: 0.85%;

[0100] Propylene glycol: 0.4%;

[0101] Sodium citrate: 0.125%;

[0102] Sodium lactate: 0.4%;

[0103] Hydroxypropyl methylcellulose: 0.25%;

[0104] Potassium sorbate: 0.125%;

[0105] Phenoxyethanol: 0.175%;

[0106] Disodium EDTA: 0.03%;

[0107] Triethanolamine: 0.175%;

[0108] Deionized water: Add to 100%.

[0109] Preparation steps:

[0110] S1. Slowly add 0.75% carbomer to deionized water at room temperature and stir at medium speed (about 350 rpm) for 40 minutes to form a uniformly dispersed transparent colloid. Add 0.175% triethanolamine to adjust the pH to 4.1±0.1 and continue stirring for 10 minutes to enhance the initial viscoelastic structure of the system.

[0111] S2. Add 2.1% polyvinyl alcohol (completely dissolved in an 80°C water bath for 30 minutes beforehand), 0.35% sodium hyaluronate, 0.25% hydroxypropyl methylcellulose, 0.85% glycerol and 0.4% propylene glycol in sequence. Stir each component separately for no less than 15 minutes after adding it to ensure that they are fully mixed and hydrated. The total time for the entire matrix construction stage is about 70 minutes.

[0112] S3. Prepare 1% aqueous solutions of 0.05% nisin and 0.55% Lactobacillus rhamnosus metabolite powder respectively. Slowly add the solutions dropwise to the above matrix system at a constant temperature of 35°C for 15 minutes, and then stir continuously for 25 minutes to ensure that the two types of bioregulatory components are fully and evenly distributed.

[0113] S4. Dissolve 0.2% naringin in a 70% ethanol-water system (volume ratio 1:4) to prepare a solution with a concentration of 10 mg / mL. Add the solution dropwise to the system at a rate of 0.8 mL / min, while simultaneously adding 0.10% lauroyl arginine ethyl ester hydrochloride aqueous solution. Maintain the temperature ≤38℃ and the pH of the system at approximately 4.1 throughout the entire dropwise addition process.

[0114] S5. Add 0.4% sodium lactate, 0.125% sodium citrate, 0.03% disodium EDTA, 0.175% phenoxyethanol, and 0.125% potassium sorbate. After stirring for 15 minutes, the system becomes completely clear. Degas under -0.09 MPa vacuum for 15 minutes, cool to room temperature, and then fill to obtain the test sample of experimental group 3.

[0115] Control group 1 (C1): Comparative gel preparation method for gel lacking naringin:

[0116] To verify the key role of naringin in the synergistic antibacterial system of this invention, a control group 1 was set up. Under the premise that other ratio parameters were the same as those in experimental group 3, the naringin component was removed to observe the effect of its absence on the physicochemical properties and biological functions of the system. This group was used to clarify whether naringin is one of the core contributing factors to antibacterial activity and to evaluate the proportion of its synergistic mechanism with other components in the system.

[0117] Formula composition (by weight percentage):

[0118] Lauroyl arginine ethyl ester hydrochloride: 0.10%;

[0119] Nisin: 0.05%;

[0120] Lactobacillus rhamnosus metabolite dry powder: 0.55%;

[0121] Sodium hyaluronate: 0.35%;

[0122] Polyvinyl alcohol: 2.1%;

[0123] Carbomer: 0.75%;

[0124] Glycerin: 0.85%;

[0125] Propylene glycol: 0.4%;

[0126] Sodium citrate: 0.125%;

[0127] Sodium lactate: 0.4%;

[0128] Hydroxypropyl methylcellulose: 0.25%;

[0129] Potassium sorbate: 0.125%;

[0130] Phenoxyethanol: 0.175%;

[0131] Disodium EDTA: 0.03%;

[0132] Triethanolamine: 0.175%;

[0133] Deionized water: Add to 100%.

[0134] Preparation steps:

[0135] S1. Disperse 0.75% carbomer in deionized water at 25℃ and stir for 40 minutes. Then add 0.175% triethanolamine to adjust the pH to 4.1±0.1 to form a uniform initial colloidal structure.

[0136] S2. Sequentially add 2.1% polyvinyl alcohol (dissolved in an 80°C water bath and cooled for later use), 0.35% sodium hyaluronate, 0.25% hydroxypropyl methylcellulose, 0.85% glycerol, and 0.4% propylene glycol. Each component is added one at a time after the previous component has been completely dispersed. The stirring time for each step is no less than 15 minutes, and the total time for the entire matrix construction stage is controlled within 70 minutes.

[0137] S3. Prepare a 1% solution by mixing 0.05% nisin with 0.55% Lactobacillus rhamnosus metabolite powder, and slowly add it dropwise to the matrix system at 35°C. Stir for 25 minutes to ensure uniform dispersion of the biological regulator.

[0138] S4. Directly add 0.10% lauroyl arginine ethyl ester hydrochloride solution (without adding naringin), control the dropping rate to not exceed 1.0 mL / min, keep the system temperature below 38℃, and control the pH value between 4.0 and 4.3.

[0139] S5. Add 0.4% sodium lactate, 0.125% sodium citrate, 0.03% disodium EDTA, 0.175% phenoxyethanol, and 0.125% potassium sorbate, and continue stirring for 15 minutes. After confirming that the system is clear, degas under vacuum (-0.09 MPa) for 15 minutes, cool to room temperature, and then complete the filling.

[0140] Control group 2 (C2): Comparative gel preparation method for Lactobacillus rhamnosus metabolites lacking:

[0141] This group deliberately removed the key component of the probiotic mechanism in this invention—the dried powder of Lactobacillus rhamnosus metabolites—to construct a one-way antibacterial system without probiotic metabolic support. Without changing the mass percentage of other components or the preparation process, the group evaluated the role of this probiotic factor in regulating pH buffering capacity, probiotic colonization stability, and local irritation.

[0142] Formula composition (by weight percentage):

[0143] Naringin: 0.2%;

[0144] Lauroyl arginine ethyl ester hydrochloride: 0.10%;

[0145] Nisin: 0.05%;

[0146] (Without adding Lactobacillus rhamnosus metabolite powder);

[0147] Sodium hyaluronate: 0.35%;

[0148] Polyvinyl alcohol: 2.1%;

[0149] Carbomer: 0.75%;

[0150] Glycerin: 0.85%;

[0151] Propylene glycol: 0.4%;

[0152] Sodium citrate: 0.125%;

[0153] Sodium lactate: 0.4%;

[0154] Hydroxypropyl methylcellulose: 0.25%;

[0155] Potassium sorbate: 0.125%;

[0156] Phenoxyethanol: 0.175%;

[0157] Disodium EDTA: 0.03%;

[0158] Triethanolamine: 0.175%;

[0159] Deionized water: Add to 100%.

[0160] Preparation steps:

[0161] S1. At room temperature (25℃), add 0.75% carbomer to deionized water and stir for 40 minutes to form a uniform colloidal dispersion. Add 0.175% triethanolamine to adjust the pH to 4.1±0.1 and continue stirring for 10 minutes.

[0162] S2. Add 2.1% polyvinyl alcohol (dissolved in an 80°C water bath and cooled for later use), 0.35% sodium hyaluronate, 0.25% hydroxypropyl methylcellulose, 0.85% glycerol and 0.4% propylene glycol one by one and stir thoroughly. After each component is evenly dispersed, proceed to the next step. The total matrix construction time should not be less than 70 minutes.

[0163] S3. Prepare a 1% aqueous solution of 0.05% nisin and slowly add it dropwise to the above matrix system at 35°C. Stir for 25 minutes to form a basic one-way antibacterial factor system. (Do not add Lactobacillus rhamnosus metabolite solution in this step).

[0164] S4. Separately, 0.2% naringin was pre-dissolved in a 70% ethanol-water system (volume ratio 1:4) to a concentration of 10 mg / mL, and then slowly added dropwise to the system together with 0.10% lauroyl arginine ethyl ester hydrochloride aqueous solution. The dropping rate was controlled within 0.8 mL / min, and the system temperature was kept ≤38℃ and the pH value was maintained in the range of 4.1.

[0165] S5. Add 0.4% sodium lactate, 0.125% sodium citrate, 0.03% disodium EDTA, 0.175% phenoxyethanol, and 0.125% potassium sorbate. Stir for 15 minutes until the system becomes clear. Degas under -0.09 MPa vacuum for 15 minutes, cool to room temperature, and then complete the filling process.

[0166] Control group 3 (C3): Comparative gel preparation method where the proportion of core components exceeds the specified range:

[0167] To verify the importance of the core component ratio range set in this invention for the system's stability and biological function, a control group 3 was designed. In this control group, the proportions of the three key components—naringin, lauroyl arginine ethyl ester hydrochloride, and carbomer—were exceeded the set upper limits, while the remaining components remained unchanged. This comparison further verifies the rationality and innovation of the formulation setting in this invention.

[0168] Formula composition (by weight percentage):

[0169] Naringin: 0.5% (exceeding the upper limit of 0.3%);

[0170] Lauroyl arginine ethyl ester hydrochloride: 0.25% (exceeding the upper limit of 0.15%);

[0171] Nisin: 0.05%;

[0172] Lactobacillus rhamnosus metabolite dry powder: 0.55%;

[0173] Sodium hyaluronate: 0.35%;

[0174] Polyvinyl alcohol: 2.1%;

[0175] Carbomer: 1.5% (exceeding the upper limit of 1.0%);

[0176] Glycerin: 0.85%;

[0177] Propylene glycol: 0.4%;

[0178] Sodium citrate: 0.125%;

[0179] Sodium lactate: 0.4%;

[0180] Hydroxypropyl methylcellulose: 0.25%;

[0181] Potassium sorbate: 0.125%;

[0182] Phenoxyethanol: 0.175%;

[0183] Disodium EDTA: 0.03%

[0184] Triethanolamine: 0.175%;

[0185] Deionized water: Add to 100%.

[0186] Preparation steps:

[0187] S1. Add 1.5% carbomer to deionized water and stir at 25°C for 40 minutes to form a high-concentration initial gel. Add 0.175% triethanolamine to adjust the pH to 4.1±0.1 to form a high-viscosity system.

[0188] S2, add 2.1% polyvinyl alcohol (dissolved in an 80°C water bath), 0.35% sodium hyaluronate, 0.25% hydroxypropyl methylcellulose, 0.85% glycerol, and 0.4% propylene glycol sequentially. Maintain the same stirring time as in T3 to ensure matrix formation.

[0189] S3. Prepare a 1% solution by mixing 0.05% nisin with 0.55% dried powder of Lactobacillus rhamnosus metabolites, add the solution to the system at 35°C, and stir for 25 minutes to form a stable dispersion.

[0190] S4, naringin was dissolved in 70% ethanol-water (1:4) to 10 mg / mL and then slowly added dropwise (total amount 0.5%). At the same time, 0.25% lauroyl arginine ethyl ester hydrochloride solution was added, and the dropping rate was controlled at 1.0 mL / min. The system temperature was maintained below 38℃.

[0191] S5. Add 0.4% sodium lactate, 0.125% sodium citrate, 0.03% disodium EDTA, 0.175% phenoxyethanol and 0.125% potassium sorbate. Stir for 15 minutes until the system is clear. Degas under -0.09 MPa vacuum for 15 minutes, cool and fill to obtain the control sample.

[0192] Control group 4 (C4): Comparison of typical antibacterial gel formulations in existing technologies:

[0193] To evaluate the overall improvement effect of the present invention compared with existing gynecological antibacterial preparations, a control group (Group 4) was set up, and representative monophasic antibacterial gel solutions from published patent literature and existing commercially available products were selected as reference models. These solutions typically use carbomer as a gel matrix, contain 1-2 antibacterial agents, do not contain probiotics or probiotic metabolites, have a simple structure, and lack a synergistic ratio control mechanism. They are suitable for basic gynecological antibacterial applications, but have significant shortcomings in terms of microecological regulation and system stability.

[0194] Formula composition (by weight percentage):

[0195] Benzalkonium chloride: 0.1% (a commonly used broad-spectrum surfactant antibacterial agent);

[0196] Chlorhexidine acetate: 0.05% (cationic bactericide);

[0197] Carbomer: 1.0%;

[0198] Glycerin: 1.0%;

[0199] Propylene glycol: 1.0%;

[0200] Sodium citrate: 0.1%;

[0201] Sodium lactate: 0.1%;

[0202] Triethanolamine: 0.2%;

[0203] Phenoxyethanol: 0.2%;

[0204] Deionized water: Add to 100%.

[0205] Preparation method:

[0206] S1. Add 1.0% carbomer to deionized water at room temperature and stir for 30 minutes until fully swollen. Add 0.2% triethanolamine dropwise to adjust the pH to 4.3, and continue stirring for 10 minutes to form a preliminary gel.

[0207] S2. Add 1.0% glycerol and 1.0% propylene glycol sequentially and stir for 15 minutes; then add 0.1% sodium citrate and 0.1% sodium lactate to adjust the buffering capacity.

[0208] S3. Dissolve 0.1% benzalkonium chloride and 0.05% chlorhexidine acetate directly in a small amount of water, and slowly add them dropwise to the matrix while stirring for 15 minutes. Finally, add 0.2% phenoxyethanol as a preservative and stir for another 5 minutes to complete the process.

[0209] Comparative experimental design:

[0210] To systematically evaluate the functional performance of the gynecological antibacterial gel described in this invention under different component ratios, verify the mechanism of action of each synergistic factor, and clarify its technological advancements compared to existing technologies, the following comparative experiment was designed. The experiment included six groups: experimental group 1, experimental group 2, experimental group 3, control group 1 (deficient in naringin), control group 2 (deficient in Lactobacillus rhamnosus metabolite dry powder), control group 3 (proportion exceeding the limit), and control group 4 (existing technology formulation).

[0211] Experimental grouping and sample preparation:

[0212] Samples from both the experimental and control groups were prepared according to the formulas and steps listed in the aforementioned examples. After preparation, the samples were sealed and stored at room temperature (25°C) for 48 hours before use. All sample preparation operations were completed in a clean operating table to avoid cross-contamination of microorganisms.

[0213] 1. Antibacterial performance test:

[0214] The inhibitory ability of the samples against common vaginal pathogens, including Candida albicans, Gardnerella vaginalis, Ureaplasma urealyticum, and Staphylococcus aureus, was evaluated using the agar diffusion method, as shown in Table 1.

[0215] All strains were purchased from the standard strain library and diluted to 1×10⁻⁶ after resuscitation culture. 6 CFU / mL was inoculated onto MHA plates, and after punching wells, samples from each group were added. The plates were then incubated at 37°C for 24 hours, and the diameter of the inhibition zone was measured to evaluate the differences in antibacterial ability.

[0216] Table 1 Experimental bacterial strains and culture conditions

[0217]

[0218] 2. Probiotic survival and colonization simulation experiment:

[0219] Lactobacillus rhamnosus GR-1 and Lactobacillus ATCC 11443 probiotic strains were selected and inoculated into an artificial vaginal epithelial model system (a 3D model constructed from human cervical epithelial cells). After spreading the samples, they were incubated at 37°C and 5% CO2 for 48 hours. The colony density and surface distribution were observed by colony counting and fluorescence staining to evaluate the differences in the probiotic support capacity of different samples.

[0220] 3. pH buffering capacity test:

[0221] Each sample was added dropwise to simulated artificial vagina solutions with pH values ​​of 4.5, 6.0, and 7.5, respectively. The pH regulation ability and rate under different background environments were observed, and the stabilization time and fluctuation range of the pH value of the system after regulation were recorded to evaluate its dynamic regulation ability in real microecological fluctuation scenarios.

[0222] 4. Evaluation of Adhesion and Retention:

[0223] A vaginal mucosa model was simulated using an inclined glass plate. Equal amounts of sample were dropped onto the model surface and the temperature was adjusted to a biomimetic temperature (37°C). The sliding distance and sliding time of the gel at a certain angle (30°) were tested to analyze the initial adhesion and surface retention capacity of the gel. The residual rate was evaluated by artificial mucosa model + colorimetric tracer method.

[0224] Experimental data:

[0225] 1. The results of the antibacterial performance test (unit: mm, diameter of the inhibition zone) are shown in Table 2:

[0226] Table 2 Results of antibacterial performance test

[0227]

[0228] 2. The results of the probiotic survival and colonization simulation experiment are shown in Table 3:

[0229] Table 3 Results of Probiotic Survival and Colonization Simulation Experiment

[0230]

[0231] 3. pH buffering capacity test (time required for pH to recover to 4.2±0.1, min), as shown in Table 4:

[0232] Table 4. Results of pH buffering capacity test

[0233]

[0234] 4. The results of the adhesion and retention tests are shown in Table 5:

[0235] Table 5 Results of Adhesion and Retention Tests

[0236]

[0237] Data Analysis:

[0238] Based on the antibacterial performance test results, such as Figure 2 As shown, experimental group 2 exhibited the largest inhibition zone diameter among four representative vaginal pathogens, with the most significant inhibitory effect against Candida albicans and Staphylococcus aureus. Experimental group 3 followed closely behind. Experimental group 1, due to its component concentration being at the lower limit, showed relatively weak antibacterial efficacy. Control group 1, lacking naringin, showed a significantly smaller inhibition zone, suggesting that naringin not only plays a direct role in the synergistic antibacterial system of this invention but also enhances the overall effect through synergistic interaction with nisin and lauroyl arginine ethyl hydrochloride. Although control group 4 also contained antibacterial components, its narrow antibacterial spectrum and weak efficacy were due to its simple system structure and insufficient dosage form stability, making it incomparable to the multi-pathway synergistic structure constructed in this invention.

[0239] In probiotic colonization simulation experiments, such as Figure 3 As shown, experimental group 2 formed a complete and uniform Lactobacillus rhamnosus colonization layer within a given time, and the colonization density of experimental group 3 also remained at a good level. Control group 2 failed to colonize probiotics due to the lack of probiotic metabolites, indicating that metabolites play a key role in maintaining the local microenvironment and promoting probiotic adhesion. In contrast, the existing technology control group 4 failed to form effective colonization within 48 hours, further verifying the necessity and practical effect of the "promoting bacterial phase" construction strategy of this invention.

[0240] pH buffering capacity test results show that, Figure 4 As shown, experimental group 2 can rapidly adjust the system to the target weakly acidic range under various initial pH conditions, with the shortest adjustment time and the best buffer stability; experimental group 3 is second best, while the adjustment effect of experimental group 1 decreases under high pH conditions. Control groups 1 and 4 have slow adjustment speed and short stabilization time in high pH simulated solutions, and the pH value fluctuates greatly, which easily leads to local acid-base imbalance. This verifies the practical value of the acid-base stable range constructed by the synergistic ratio in this invention for the regulation of vaginal microecology.

[0241] In terms of adhesion and retention testing, such as Figure 5 , Figure 6As shown, experimental groups 2 and 3 exhibited excellent adhesion and retention capabilities, with short sliding distances, high residue rates, and good structural extensibility on the inclined plane. In contrast, control group 4, due to its simple structure and lack of gel-regulating components, had long sliding distances and short retention times, which were not conducive to long-term effects. Although control group 3 had strong retention, the excessive carbomer ratio resulted in an overly viscous system, which could easily cause discomfort in actual use. This demonstrates that the ratio range defined in this invention not only establishes a good performance boundary but also ensures comfort and safety in use.

[0242] In summary, this invention achieves multi-dimensional regulation of the vaginal microecology by constructing a dual-structure system of "antibacterial phase + probacterial phase", designing synergistic ratios between components, and defining core parameter ranges. It outperforms existing technologies or control schemes lacking synergistic mechanisms in key performance aspects such as antibacterial, probacterial, adhesion, and buffering regulation, demonstrating significant technological advancement and practical application value.

[0243] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A gynecological antibacterial gel, characterized in that, Includes the following components by mass percentage: Naringin 0.1%–0.3%; Lauroyl arginine ethyl ester hydrochloride 0.05%–0.15%; Nisin 0.02%–0.08%; Lactobacillus rhamnosus metabolite dry powder: 0.3%–0.8%; Sodium hyaluronate 0.2%–0.5%; Polyvinyl alcohol 1.2%–3.0%; Carbomer 0.5%–1.0%; Glycerin 0.5%–1.2%; Propylene glycol 0.2%–0.6%; Sodium citrate 0.05%–0.2%; Sodium lactate 0.2%–0.6%; Hydroxypropyl methylcellulose 0.1%–0.4%; Potassium sorbate 0.05%–0.2%; Phenoxyethanol 0.1%–0.25%; Disodium EDTA 0.01%–0.05%; Triethanolamine 0.1%–0.25%; The remainder is deionized water; The mass ratio of naringin, nisin and lauroyl arginine ethyl hydrochloride is (4-6):(1-1.5):(1-2). The mass ratio of Lactobacillus rhamnosus metabolites, sodium hyaluronate, and polyvinyl alcohol is (2-3):(1-1.5):(3-5). The mass ratio of carbomer to triethanolamine is (2.5–4):1; The combined mass fraction of glycerol, propylene glycol, and hydroxypropyl methylcellulose is 1.2%–2.2%. The gel has a pH of 4.0–4.5, exhibits a uniform semi-solid appearance when left to stand at 25°C, and has a shear rate of 10 s⁻¹. -1 The viscosity is 8000–14000 mPa·s, and no visible layering, precipitation or sedimentation occurs within 48 hours.

2. The gynecological antibacterial gel according to claim 1, characterized in that, The naringin was obtained by pulverizing the crude material obtained from the peel of citrus fruits after low-temperature drying to a moisture content of no more than 8%. The extraction solvent was a 70% ethanol-water system with a material-to-liquid ratio of 1:

10. The extraction was carried out by ultrasonic extraction at 55°C for 2 hours. The resulting extract was concentrated under reduced pressure, filtered to remove impurities, cooled to crystallize, and then filtered and dried to obtain a yellow crystalline powder.

3. The gynecological antibacterial gel according to claim 1, characterized in that, The lauroyl arginine ethyl ester hydrochloride is a salt-type amphoteric compound obtained by neutralization after condensation esterification of lauric acid and L-arginine. The product is a white or off-white crystalline powder with a drying loss of no more than 5% and a particle size D90 of less than 80 μm. It dissolves in an aqueous phase at 25°C to form a clear solution.

4. The gynecological antibacterial gel according to any one of claims 1 to 3, characterized in that, The lactic acid nisin is a peptide component derived from the liquid fermentation broth of *Streptococcus lactis*. After filtration through a 0.2 μm ceramic membrane, desalination with a strong acid resin, and concentration via reverse osmosis, it is freeze-dried to obtain a powdered solid. The molecular weight of this substance ranges from 2500 to 3500 Da, its whiteness is not less than 80%, its solubility in deionized water at 25°C is ≥10 mg / mL, and the pH of the resulting solution is 6.5 to 7.

0.

5. The gynecological antibacterial gel according to claim 1, characterized in that, The Lactobacillus rhamnosus metabolite is a white to pale yellow powder prepared by spray drying after the cell supernatant obtained by deep liquid fermentation is concentrated to 1 / 6 of its original volume by an ultrafiltration membrane with a molecular retention limit of 3000 Da. The powder has a solid content of not less than 90% and a water content of less than 5%.

6. The gynecological antibacterial gel according to claim 1 or 5, characterized in that, The sodium hyaluronate is a medium molecular weight product produced by fermentation, with a number average molecular weight of 7 × 10⁻⁶. 4 ~1.2×10 5 Da, in its dry powder state, has a moisture content of less than 8%, and its 0.5% aqueous solution has a viscosity of 1000-1500 mPa·s at 25℃.

7. The gynecological antibacterial gel according to claim 1, characterized in that, The glycerol and propylene glycol are pharmaceutical-grade liquid components, with contents of 0.5%–1.2% and 0.2%–0.6%, respectively. The glycerol has a trihydroxypropane structure and a viscosity of 1000–1500 mPa·s at 25°C, while the propylene glycol is a colorless, transparent liquid with a density of 1.036 g / cm³. 3 The two are added and mixed separately during the matrix stage, with a total amount not exceeding 1.8%; the hydroxypropyl methylcellulose is a low-viscosity white powder with a particle size controlled between 80 and 120 mesh.

8. The method for preparing the gynecological antibacterial gel according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1. Constructing the initial dispersed phase and adjusting the pH: Carbomer was added to deionized water at 25°C and stirred for 30-45 minutes until completely dispersed to obtain the initial dispersed phase. Triethanolamine was then added to adjust the pH to 4.1±0.1, and stirring was continued for 10 minutes. S2. Gradually construct the gel matrix system: Add polyvinyl alcohol, sodium hyaluronate, hydroxypropyl methylcellulose, glycerol and propylene glycol in sequence. Each component is added after the previous component is completely dispersed. Stir for at least 15 minutes after each component is added. The entire matrix construction stage lasts for at least 60 minutes. S3. Introduction of bioregulatory functional components: Nisin and Lactobacillus rhamnosus metabolites were dissolved in deionized water to prepare a 1% mass concentration solution, which was then added dropwise to the matrix system at 35°C and stirred for 25 minutes to form a uniform dispersion. S4. Add synergistic antibacterial active ingredients: Add lauroyl arginine ethyl ester hydrochloride and naringin pre-solution, control the dropping rate to within 1.0 mL / min, maintain the system temperature not higher than 38℃, and keep the pH value stable between 4.0 and 4.3; S5. Add auxiliary components and complete final conditioning: Add sodium lactate, sodium citrate, disodium EDTA, phenoxyethanol, and potassium sorbate, stir for 15 minutes, clarify the system, degas under vacuum at -0.09 MPa for 15 minutes, cool to room temperature, and then fill to obtain the finished product.

9. The preparation method according to claim 8, characterized in that, In step S4, the naringin is pre-dissolved in a 1:4 volume ratio 70% ethanol-water system at a concentration of 10 mg / mL. It is then slowly added dropwise to the preparation system at a volume ratio not exceeding 3%, with the dropping rate controlled at 0.5–1.0 mL / min. During the dropping process, the mixture is continuously stirred at a speed of 300 rpm. After the dropping is completed, stirring is continued for 15 minutes.

10. The preparation method according to claim 8, characterized in that, In step S2, polyvinyl alcohol is added before other matrix components and dissolved in an 80°C water bath for 30 minutes. After cooling to below 35°C, sodium hyaluronate is added. Hydroxypropyl methylcellulose is then slowly added while stirring for 30 minutes. During the mixing process, the pH value of the system remains stable in the range of 4.2±0.1.

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