Uridil gel for bacteriostasis and its preparation method

Abstract

The present application relates to the technical field of gynecological bacteriostatic gel, and particularly relates to a ulipristal bacteriostatic gel and a preparation method thereof; the ulipristal bacteriostatic gel comprises the following components in parts by weight: chlorhexidine acetate 1-3 parts, meihua grass extract 4-8 parts, carbomer 0.8-1.2 parts, triethanolamine 0.4-0.6 parts, penetration enhancer 0.5-1.5 parts, modified nano-silver 0.04-0.07 parts, glycerol 5-8 parts, hydrogenated polyisobutylene 0.03-0.07 parts, disodium edetate 0.1-0.3 parts and purified water in a remainder amount; the chlorhexidine acetate and the meihua grass ethanol extract are compounded at a ratio of 1:(2.5-4), the flavones and polyphenols in the meihua grass can destroy the cell membrane permeability of microorganisms, promote the chlorhexidine acetate to enter the inside of the microorganism, and significantly reduce the minimum bacteriostatic concentration.

Description

Technical Field

[0001] This invention relates to the field of gynecological antibacterial gel technology, specifically to a Ulidig antibacterial gel and its preparation method. Background Technology

[0002] Gynecological inflammation is a common gynecological disease, mainly classified into bacterial vaginosis, fungal vaginitis, nonspecific vaginitis, and trichomonal vaginitis. According to incomplete statistics from the World Health Organization, the incidence of various gynecological diseases among women is over 65%, and it is showing a trend towards affecting younger women, becoming one of the major threats to the health of women in China. Treatment methods for gynecological inflammation include physical therapy and drug therapy. Physical therapy can cause damage to epithelial cells; drug therapy is mostly based on local treatment. Because the vagina has abundant capillaries and lymphatic vessels, and lacks clearly defined nerve endings, drug administration causes minimal pain and is a good site of drug release for specific diseases and medications. Therefore, various dosage forms such as suppositories, tablets, and gels are prepared for clinical use according to different treatment purposes. Gels are favored by patients due to their good user compliance.

[0003] Traditional medical antibacterial gels, such as those with announcement number CN117797195A, often rely on single chemical bactericides, such as chlorhexidine acetate or zinc salts. Long-term use can easily induce microbial resistance. For example, the carbomer gynecological gel with announcement number CN118576537A directly mixes plant extracts with chemical drugs, resulting in the carbomer gel network encapsulating the active ingredients, with a release rate of ≤60%. At the same time, tannins in the ethanol extract complex with metal ions to produce precipitation, which severely reduces the light transmittance. In view of this, we propose a Ulidige antibacterial gel and its preparation method. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings mentioned in the background section and provide an antibacterial gel called Ulidige and its preparation method.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A Ulidig antibacterial gel comprises the following components by weight: 1-3 parts chlorhexidine acetate, 4-8 parts *Prunus armeniaca* extract, 0.8-1.2 parts carbomer, 0.4-0.6 parts triethanolamine, 0.5-1.5 parts penetration enhancer, 0.04-0.07 parts modified nano-silver, 5-8 parts glycerin, 0.03-0.07 parts hydrogenated polyisobutylene, 0.1-0.3 parts disodium edetate, and the balance being purified water;

[0007] The mass ratio of chlorhexidine acetate to plum blossom extract is 1:(2.5-4).

[0008] Preferably, the modified silver nanoparticles are polydopamine-coated silver nanoparticles with a particle size of 10-20 nm, prepared by in-situ reduction of silver nitrate with dopamine under alkaline conditions.

[0009] Preferably, the plum blossom grass extract is an ethanol gradient extract, and the extraction process includes:

[0010] Step 1: Extract with 56-67% ethanol at 50°C for 1.5 hours;

[0011] Step 2: Extract at 25℃ for 2 hours;

[0012] Step 3: Soak and extract at 4℃ for 12 hours.

[0013] Preferably, the viscosity of the Ulidige antibacterial gel is 11500-12500 mPa·s.

[0014] Preferably, the penetration enhancer is borneol.

[0015] A method for preparing an antibacterial gel, comprising the following steps:

[0016] Step 1: Disperse carbomer in purified water with a total water content of 60% and allow it to swell for 12 hours to obtain a pregel matrix;

[0017] Step 2: Extract the raw material of Prunus mume with a gradient of 56-67% ethanol, filter to obtain Prunus mume extract, add chlorhexidine acetate to it and stir to activate it, and obtain a mixture.

[0018] Step 3: Slowly add the mixture obtained in Step 2 to the pregel matrix in Step 1, and stir at 400 rpm for 15 minutes;

[0019] Step 4: Then add borneol, sonicate for 10 minutes, and then add triethanolamine dropwise to adjust the pH to 5.8-6.2;

[0020] Step 5: Finally, add glycerol, hydrogenated polyisobutylene, disodium edetate and the remaining purified water, and degas under vacuum at -0.08 MPa for 10 minutes to obtain Ulidig antibacterial gel.

[0021] Preferably, the activation conditions for step two are: stirring at 200 rpm for 30 minutes at 35±2℃.

[0022] Preferably, the ultrasonic dispersion power in step four is 300-400W.

[0023] Ulidig antibacterial gel is used in the preparation of gynecological external antibacterial preparations for the treatment of vaginal infections caused by Candida albicans or Staphylococcus aureus.

[0024] Compared with the prior art, the beneficial effects of the present invention are:

[0025] 1. This invention uses chlorhexidine acetate and ethanol extract of *Smilax china* in a ratio of 1:(2.5-4). The flavonoids and polyphenols in *Smilax china* can disrupt the permeability of microbial cell membranes, promote the entry of chlorhexidine acetate into the bacterial cells, and significantly reduce the minimum inhibitory concentration. Therefore, the combination has a 40% higher inhibition rate against Staphylococcus aureus than a single component, and can delay the development of bacterial resistance. Compared with the existing technology that uses chemical antibacterial agents or ordinary Chinese herbal medicines alone, this solution achieves broad-spectrum antibacterial activity through a chemical-plant complex antibacterial pathway, and has a specific inhibitory effect on common gynecological pathogens (Candida albicans, Escherichia coli).

[0026] 2. This invention extracts *Hedyotis diffusa* raw material in 56-67% ethanol using a three-stage gradient temperature control (50℃ initial extraction → 25℃ intermediate extraction → 4℃ fine extraction) to maximize the extraction of small-molecule polar components with antibacterial activity (such as saponins and flavonoids), avoiding degradation of heat-sensitive components. Compared with the traditional water decoction method, the yield of antibacterial active components is increased by 32%. Chlorhexidine acetate is directly added to the filtered *Hedyotis diffusa* extract, and the ethanol solvent environment is used to depolymerize its molecules into active monomers, avoiding the crystal form changes caused by secondary dissolution in the traditional process.

[0027] 3. In this invention, modified nano-silver is added to the gel. It is prepared by in-situ reduction of dopamine-sodium hydroxide. The polydopamine layer coated on the surface of the nano-silver can combine with the carboxyl groups in the carbomer network to form a sustained-release unit, which extends the release time of chlorhexidine acetate to more than 24 hours. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The present invention will describe the above technical solution in detail through the following embodiments:

[0030] Example 1

[0031] A Ulidig antibacterial gel comprises the following components by weight: 1.5 parts chlorhexidine acetate, 3.75 parts *Prunus armeniaca* extract, 1.0 part carbomer, 0.5 parts triethanolamine, 1.0 part borneol, 0.05 parts modified nano-silver, 7 parts glycerin, 0.05 parts hydrogenated polyisobutylene, 0.2 parts disodium edetate, and the balance being purified water;

[0032] The mass ratio of chlorhexidine acetate to plum blossom extract is 1:(2.5-4).

[0033] Specifically, the preparation method of modified silver nanoparticles is as follows: 10 mg of dopamine is dissolved in 50 mL of pH 8.5 Tris-HCl buffer, 1 mM silver nitrate solution is added, and the mixture is stirred at 25°C in the dark for 24 h. After centrifugation and washing (12000 rpm × 10 min), polydopamine-coated silver nanoparticles are obtained.

[0034] The modified nano-silver is a polydopamine-coated nano-silver particle with a particle size of 15 nm, which is prepared by in-situ reduction of silver nitrate by dopamine under alkaline conditions.

[0035] Preferably, the plum blossom grass extract is an ethanol gradient extract, and the extraction process includes:

[0036] Step 1: Extract with 67% ethanol at 50°C for 1.5 hours;

[0037] Step 2: Extract at 25℃ for 2 hours;

[0038] Step 3: Soak and extract at 4℃ for 12 hours.

[0039] Among them, the viscosity of Ulidige antibacterial gel is 12500 mPa·s.

[0040] A method for preparing an antibacterial gel, comprising the following steps:

[0041] Step 1: Disperse carbomer in purified water with a total water content of 60% and allow it to swell for 12 hours to obtain a pregel matrix;

[0042] Step 2: Extract the raw material of Prunus mume with 67% ethanol in a gradient. After filtration, obtain the Prunus mume extract. Add chlorhexidine acetate to the extract and stir to activate it. The activation conditions are: stir at 200 rpm for 30 minutes at 35±2℃ to obtain a mixture.

[0043] Step 3: Slowly add the mixture obtained in Step 2 to the pregel matrix in Step 1, and stir at 400 rpm for 15 minutes;

[0044] Step 4: Then add borneol, sonicate for 10 minutes, and then add triethanolamine to adjust the pH to 5.8. The sonication power is 300W.

[0045] Step 5: Finally, add glycerol, hydrogenated polyisobutylene, disodium edetate and the remaining purified water, and degas under vacuum at -0.08 MPa for 10 minutes to obtain Ulidig antibacterial gel.

[0046] It should be noted that carbomer is pre-swollen in 60% total water for 12 hours to form a homogeneous hydrated layer, which differs from the conventional stirring swelling method. This ensures that the gel is free of particles. Chlorhexidine acetate is mixed with the herb extract first, and then the carbomer matrix is ​​slowly added to avoid the dense network formed when carbomer is neutralized with triethanolamine, which would encapsulate the drug and delay release. After adding triethanolamine, degassing is performed at -0.08 MPa for 10 minutes to eliminate the influence of air bubbles on the gel viscosity.

[0047] Example 2

[0048] The only difference between this embodiment and Embodiment 1 is that in this embodiment, chlorhexidine acetate is 1.5 parts and plum blossom grass extract is 4.5 parts, while all other conditions are the same.

[0049] Example 3

[0050] The only difference between this embodiment and Embodiment 1 is that in this embodiment, 1.5 parts of chlorhexidine acetate and 6 parts of plum blossom grass extract are used, while all other conditions are the same.

[0051] Example 4

[0052] The only difference between this embodiment and Embodiment 1 is that in this embodiment, chlorhexidine acetate is 1 part and plum blossom grass extract is 4 parts, while all other conditions are the same.

[0053] Comparative Example 1

[0054] The only difference between this comparative example and Example 1 is that no modified nano-silver is added in this comparative example, while all other conditions are the same.

[0055] Comparative Example 2

[0056] The only difference between this comparative example and Example 1 is that no borneol is added in this comparative example, while all other conditions are the same.

[0057] Comparative Example 3

[0058] The only difference between this comparative example and Example 1 is that the plum blossom extract in this comparative example omits the gradient extraction and instead undergoes a single extraction at 50°C, while all other conditions remain the same.

[0059] Comparative Example 4

[0060] The only difference between this comparative example and Example 1 is that the carbomer in this comparative example is omitted from the 12-hour pre-swelling process in 60% of the total water volume, while all other conditions are the same.

[0061] Test items:

[0062] I. Minimum Inhibitory Concentration (MIC) Test

[0063] Standard: GB / T 20944.3-2008 Evaluation of antibacterial properties, shaking method

[0064] Procedure: 1. Activation of bacterial strains: Candida albicans (ATCC 10231) and Staphylococcus aureus (ATCC 6538) were inoculated into SDA / TSB medium and incubated at 37°C for 24 h.

[0065] Twofold dilution method: Dilute the gel extract with MH broth to a gradient concentration of 0.39-50 μg / mL.

[0066] Add bacteria for incubation: Add 1×10⁻⁶ bacteria to each tube. 6 CFU / mL bacterial culture, cultured at 37℃ with shaking for 24 h.

[0067] Judgment: The lowest concentration at which no turbidity is observed to the naked eye is the MIC.

[0068] II. Biofilm clearance rate test

[0069] Standard: Modified CLSI M27-A3 protocol (quantitative laser confocal microscopy)

[0070] Procedure: 1. Biofilm construction: Candida albicans was inoculated into 96-well plates (RPMI 1640 containing 10% FBS) and cultured at 37°C for 48 h to form a mature biofilm.

[0071] Gel treatment: Add 0.2 mg / mL gel extraction solution to each well and incubate for 24 h.

[0072] Fluorescent staining: SYTO9 / PI double staining (live bacteria - green, dead bacteria - red).

[0073] CLSM analysis: Calculate the percentage of red pixels (mortality rate) = clearance rate.

[0074] III. Cumulative Release Rate Test

[0075] Standard: Chinese Pharmacopoeia 2020 Edition, 0931, Determination of Release Rate

[0076] Procedure: 1. Dialysis bag method: Take 1.0 g of gel and place it into a dialysis bag with a molecular weight cutoff of 8-14 kDa.

[0077] Receiving medium: 500 mL pH 4.5 acetate buffer (simulating vaginal environment), 37℃±0.5℃, rotation speed 50 rpm.

[0078] Sampling points: 5 mL of receiving solution at 2, 4, 6, 12, and 24 hours (with simultaneous replenishment).

[0079] HPLC detection: C18 column (4.6×250 mm), mobile phase acetonitrile-0.1% phosphoric acid (35:65), flow rate 1.0 mL / min, detection wavelength 254 nm.

[0080] IV. Rabbit Mucosal Irritation Test

[0081] Standard: Disinfection Technical Specifications (2002 Edition)

[0082] Procedure: 1. Animal grouping: New Zealand White Rabbits (female, 2.5-3.0 kg), 6 rabbits per group.

[0083] Administration: Inject 0.2 g of gel into the vagina daily for 7 consecutive days.

[0084] Scoring: 24 hours after the last administration, anatomical observation of the mucosa: 0 points: no redness or swelling, 1 point: mild congestion, 2 points: moderate congestion / edema, 3 points: severe congestion / ulceration, 4 points: necrosis.

[0085] The specific data is shown in Table 1 below:

[0086] Table 1

[0087]

[0088] *Note: Comparative Example 4 showed release stagnation after 6 hours (gel particles blocked the dialysis membrane).

[0089] The data in the table above show that, based on the data from Examples 1 and 4, when the ratio of chlorhexidine acetate to *Prunus armeniaca* extract is 1:2.5, the MIC is the lowest (0.78 μg / mL), and the biofilm clearance rate is the highest, reaching 91.2%. When the ratio of chlorhexidine acetate to *Prunus armeniaca* extract increases to 1:4, the MIC increases by 100%, and the clearance rate decreases by 5.6%.

[0090] Data from Comparative Examples 1 and 2 show that when no modified nano-silver was added, the release rate plummeted by 31.1% (92.3% → 61.2%), demonstrating the crucial role of nano-silver in sustained release. The biofilm clearance rate decreased by 21% due to the lack of silver ions for synergistic penetration. Furthermore, when no borneol was added, the biofilm clearance rate decreased by 25.4% due to the loss of its permeation-enhancing function.

[0091] Data from Comparative Examples 3 and 4 show that when a single extraction was used, the MIC spiked to 3.13 μg / mL. Gradient temperature control ensured the activity of the heat-sensitive components. When carbomer was not pre-swollen in 60% of the total water volume for 12 hours, the release rate decreased by 23% due to gel particle blockage, and the transmittance decreased by 7.7% due to precipitation causing turbidity.

[0092] In summary, Example 1 (chlorhexidine acetate: senna = 1:2.5) achieved peak antibacterial efficacy (MIC 0.78 μg / mL), biofilm clearance (91.2%), and release rate (92.3%).

[0093] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within the present invention.

Claims

1. A Ulidig antibacterial gel, characterized in that: The product comprises the following components by weight: 1-3 parts chlorhexidine acetate, 4-8 parts *Prunus armeniaca* extract, 0.8-1.2 parts carbomer, 0.4-0.6 parts triethanolamine, 0.5-1.5 parts penetration enhancer, 0.04-0.07 parts modified nano-silver, 5-8 parts glycerol, 0.03-0.07 parts hydrogenated polyisobutylene, 0.1-0.3 parts disodium edetate, and the balance being purified water; The mass ratio of chlorhexidine acetate to plum blossom extract is 1:(2.5-4). The modified nano-silver is polydopamine-coated nano-silver particles with a particle size of 10-20 nm, which are prepared by in-situ reduction of silver nitrate by dopamine under alkaline conditions. The plum blossom grass extract is an ethanol gradient extract, and the extraction process includes: Step 1: Extract with 56-67% ethanol at 50°C for 1.5 hours; Step 2: Soak and extract at 25℃ for 2 hours; Step 3: Soak and extract at 4℃ for 12 hours.

2. The Ulidige antibacterial gel as described in claim 1, characterized in that: The viscosity of the Ulidige antibacterial gel is 11500-12500 mPa·s.

3. The Ulidige antibacterial gel as described in claim 1, characterized in that: The penetration enhancer used is borneol.

4. The application of the Ulidige antibacterial gel as described in claim 1 in the preparation of gynecological external antibacterial preparations, characterized in that: The gynecological topical antibacterial preparation is used to treat vaginal infections caused by Candida albicans or Staphylococcus aureus.

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