Gel for radiofrequency therapeutic apparatus used in vagina

Abstract

The invention discloses gel for an intravaginal radiofrequency therapeutic apparatus, and relates to the technical field of intravaginal radiofrequency therapy. The gel for the radio frequency therapeutic instrument is prepared from the following raw materials in percentage by mass: 0.5 to 1.5 percent of nonionic cellulose ether gel matrix, 50 to 88 percent of humectant and 0.001 to 0.01 percent of citric acid, the balance is water; the nonionic cellulose ether gel matrix is hydroxyethyl cellulose; the weight-average molecular weight of the hydroxyethyl cellulose ranges from 720,000 Da to 13,000 Da; the humectant comprises propylene glycol and glycerol in a ratio of (10-18): (40-70); the pH value of the gel for the radio frequency therapeutic instrument is 3.8-6. The gel for the radio-frequency therapeutic instrument has stable physical and chemical stability in a weak acid vagina environment, keeps stable in a radio-frequency heating state, and is free of layering and precipitation, good in viscosity maintenance and stable in electrical property.

Description

Technical Field

[0001] This invention relates to the field of intravaginal radiofrequency therapy technology, specifically a gel for an intravaginal radiofrequency therapy device. Background Technology

[0002] Radiofrequency ablation (RFA) technology has been widely used in gynecology to treat a range of conditions. During this treatment, an RFA head is inserted into the vagina and brought into contact with the mucosal tissue. Radiofrequency current is emitted to generate heat energy to achieve the therapeutic effect. To ensure effective and uniform energy delivery to the target tissue and to avoid overheating and burns to non-target tissues, a specialized gel must be used as a transmission medium between the treatment head and the mucosa. This gel not only needs to act as a lubricant but, more importantly, must possess stable electrical properties to ensure precise delivery of the RFA energy.

[0003] In existing technologies, gels for this type of in vivo therapy still have certain shortcomings: First, poor environmental compatibility: the vaginal cavity is weakly acidic (pH 3.8~4.5) and contains various ions (such as Na+). + K + Ca 2+ Currently, most gels on the market and in patents use anionic polymers such as carbomer or sodium polyacrylate as the gel matrix. However, the resulting gels will produce white flocculent precipitates such as layering in the specific acidic ionic environment of the vagina. For example, patent CN115737536A describes a gel for therapeutic devices and its preparation method. It improves the viscosity stability of carbomer-based gels in ionic environments by optimizing the preparation process. However, such anionic polymers are prone to flocculation reactions in acidic environments and when containing polyvalent metal ions, producing visible white flocculent precipitates. These precipitates not only seriously affect the observation and judgment of colposcopy, but also cause mucosal irritation or discomfort to patients. Secondly, the electrical properties are unstable: Radiofrequency ablation relies on high-frequency current, and its therapeutic effect directly depends on the stability of energy transmission. This places strict requirements on the gel to have stable and consistent impedance under radiofrequency ablation conditions. However, existing gels are prone to changes in their physical structure and composition when diluted by vaginal secretions or when the temperature rises due to the radiofrequency energy itself (tissue temperature can reach 40-45°C during treatment, and the gel's own temperature may be even higher). This leads to significant fluctuations in impedance, directly causing uneven heat distribution in the treatment area, seriously affecting the therapeutic effect and safety. For example, the ultrasonic gel with improved viscosity and stability described in patent CN108778346A focuses on the viscosity stability of the gel after γ-radiation sterilization, but does not address or solve the crucial issue of electrical impedance stability in radiofrequency ablation. Third, insufficient thermal stability: During radiofrequency treatment, the gel is in a continuously heated working environment. However, existing gels will exhibit phenomena such as layering, water separation, or a sudden drop in viscosity when the temperature rises to 40~50℃, resulting in water condensation. This leads to uneven energy transmission and reduced therapeutic heat sensation. For example, patent CN115737536A, a gel for a therapeutic device and its preparation method, indicates that vaginal secretions will dilute the gel, causing the gel structure to collapse, viscosity to decrease, and the effective action time to be shortened. This not only causes the gel to be rapidly lost from the treatment site, greatly affecting the convenience of operation, but also causes the energy transmission to be interrupted, requiring frequent replenishment of the gel, increasing the difficulty of clinical operation, and posing a risk of local thermal damage.

[0004] In summary, to address the aforementioned issues, this application provides a vaginal radiofrequency ablation gel by completely replacing the conventional carbomer matrix with nonionic hydroxyethyl cellulose and using a high-concentration glycerol-propylene glycol system as a moisturizer. This avoids the gel's sedimentation problem in specific environments and simultaneously achieves excellent impedance and thermal stability. The specific ratio of high-concentration glycerol to propylene glycol in the gel forms a dynamically stable structure that inhibits ion migration. Glycerol acts as a high-viscosity, high-resistivity substrate, while propylene glycol acts as a modifier. Their synergistic effect allows the gel to exhibit excellent dielectric stability within the required radiofrequency ablation frequency band (1MHz) and operating temperature range (room temperature to 50°C), successfully controlling the impedance change rate within ≤5%, thus solving the core problem of unstable energy transmission due to temperature increases in existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a gel for vaginal radiofrequency therapy devices to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A gel for vaginal radiofrequency therapy, the gel comprising the following ingredients by mass percentage: 0.5-1.5% nonionic cellulose ether gel matrix, 50-88% moisturizer, 0.001-0.01% citric acid; the remainder being water.

[0007] The water mentioned includes, but is not limited to, ultrapure water and deionized water.

[0008] More preferably, the nonionic cellulose ether gel matrix is ​​hydroxyethyl cellulose; the weight-average molecular weight of the hydroxyethyl cellulose is 720,000~1,300,000 Da.

[0009] In the radiofrequency therapy device gel system, non-ionic hydroxyethyl cellulose completely replaces traditional carbomer as the main gel matrix. Due to its physical entanglement and hydration, it forms a three-dimensional network structure through the physical entanglement and hydrogen bonding of long polymer chains in water. It does not rely on charge or chemical cross-linking and has stable dielectric properties under radiofrequency electric fields, which can maintain the uniformity of the gel. This effectively avoids the problems caused by electrostatic repulsion and neutralization cross-linking in carbomer gel systems. Carbomer has a large number of carboxyl groups (-COOH) on its molecular chains, which ionize into -COO⁻ in an alkaline environment. It stretches and swells due to electrostatic repulsion between chains. Carbomer gel formation requires alkali neutralization (such as triethanolamine or sodium hydroxide) to form an ionic cross-linking network with counterions. Carbomer gels encounter weak acid and ionic environments, and the ionic bond destruction and chemical cross-linking of the gel lead to sudden impedance changes and structural collapse. The selected nonionic hydroxyethyl cellulose possesses the following advantages: 1) Charge immunity: The nonionic nature of hydroxyethyl cellulose fundamentally avoids pH sensitivity issues caused by H⁺ and ionic crosslinking / precipitation issues caused by polyvalent metal ions; 2) Structural toughness: Its gel structure relies on physical chain entanglement and hydrogen bonding. This force is very strong and undisturbed within the physiological pH and ionic strength range, providing inherent structural stability; 3) Chemical inertness: Under application conditions, hydroxyethyl cellulose exhibits excellent chemical inertness, not reacting with any components of vaginal secretions that would lead to dissolution or damage to the gel network. This results in a gel with stable impedance and a stable physical state after heating.

[0010] More preferably, the moisturizer comprises (10-18):(40-70) propylene glycol and glycerin, preferably (55-65):(10-15).

[0011] The radiofrequency therapy device uses a gel with high concentrations of glycerin and propylene glycol as a moisturizer. Glycerin has a polyhydroxy structure and can form hydrogen bonds with the hydroxyethyl groups on the hydroxyethyl cellulose molecular chain, enhancing the degree of molecular chain entanglement. Propylene glycol penetrates into the gaps in the gel network, improving the flexibility of the system. The synergistic effect of the two not only strengthens the structural stability of the hydroxyethyl cellulose gel, but also maintains the viscosity of the gel through water-locking, preventing the gel from drying out or sticking together, thereby ensuring the stability and extensibility of the gel.

[0012] Ideally, the pH of the gel used in the radiofrequency therapy device is 3.8-6, preferably 3.8-4.5.

[0013] In a more optimized manner, the preparation method of the gel for the radiofrequency therapy device includes the following steps: Step 1: Add some of the humectant to the water, mix well, then add the nonionic cellulose ether gel matrix, stir well, let stand or stir to swell, and obtain the gel matrix phase; Step 2: Add the remaining moisturizer to the gel matrix phase in sequence, mix and homogenize, then continue to add the mixed solution of citric acid and water, stir for 20-30 minutes at room temperature, and defoam under vacuum to obtain the gel for radiofrequency therapy device.

[0014] Ideally, the time for standing or stirring to swell is 18-24 hours; the time for mixing and homogenizing is 8-12 minutes.

[0015] In a more optimized manner, the raw material of the gel for radiofrequency therapy device further includes 0.03-0.2% of a fiber-drawing agent, preferably 0.04%-0.06%.

[0016] Ideally, the drawing agent is polyethylene glycol-90M.

[0017] Polyethylene glycol-90M is a high-molecular-weight nonionic water-soluble polymer. The "90M" refers to its average molecular weight of approximately 9 million Daltons. Its extremely high molecular weight allows it to efficiently form fibrous structures, resulting in a "filamentous" effect. Introducing polyethylene glycol-90M into the formulation at very low concentrations imparts a unique filamentous property to the gel. The principle is that the long-chain polymer structure of polyethylene glycol-90M intertwines in the aqueous matrix, forming long, delicate, and resistant-to-break filaments when the gel is stretched. This significantly improves the gel's cohesion and extensibility, effectively solving the operational pain points of difficult gel positioning and easy loss. Furthermore, polyethylene glycol-90M exhibits good compatibility with hydroxyethyl cellulose and humectants, and it does not interfere with the stability of hydroxyethyl cellulose in acidic environments, nor does it negatively affect the crucial electrical impedance properties of the gel.

[0018] In a more optimized manner, the preparation method of the gel for the radiofrequency therapy device is as follows: Step 1: Add a portion of the moisturizer to water, mix evenly, and then add a non-ionic cellulose ether gel matrix. Stir evenly, let stand or stir to swell, and obtain the gel matrix phase. Step 2: Add the mixture of the drawing agent and water, and the remaining moisturizer to the gel matrix phase in sequence, mix and homogenize, then continue to add the mixture of citric acid and water. Stir at room temperature for 20-30 minutes, then defoam under vacuum to obtain the gel for radiofrequency therapy devices.

[0019] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) Environmental adaptability: The gel for radiofrequency therapy prepared in this application has excellent physiological environment adaptability. Under the conditions of the vagina's unique weak acid environment (pH 3.8~4.5) and the presence of multiple ions, the gel can maintain a state of no precipitation and no flocculation for a long time, and can maintain good physical stability, providing a stable medium basis for the treatment process.

[0020] (2) Thermal stability and electrical stability: The gel for radiofrequency therapy prepared in this application has both excellent thermal stability and electrical stability. Under heating conditions from room temperature to 50°C, the structure of the gel can stably maintain a state without layering or precipitation. At the same time, at the 1MHz frequency commonly used in radiofrequency therapy, its impedance change can be strictly controlled within 5%, which effectively avoids the loss of radiofrequency energy or local concentration caused by impedance fluctuations, and can ensure that the radiofrequency energy is uniformly and stably applied to the treatment site during transmission.

[0021] (3) Long-lasting performance: The gel for radiofrequency therapy prepared in this application has long-lasting anti-dilution ability. In actual application environment, in the presence of vaginal secretions, the gel will not be diluted by vaginal secretions and will not experience a sharp drop in viscosity or structural collapse. During the treatment process, it can still maintain viscosity and structure, continuously adhere to the treatment site, ensure continuous conduction of radiofrequency energy, and improve the long-lasting effect and reliability of the treatment.

[0022] (4) Clinical operation stability: The radiofrequency therapy device prepared in this application introduces a drawing agent into the gel, which enables the operator to more accurately deliver and fix the gel to the treatment target in the vagina; at the same time, the drawing effect enables the gel to better "hang" on the wall and cover the surface of the vaginal mucosal folds, forming a uniform and durable gel layer, avoiding rapid loss due to gravity or body fluid flow, and ensuring that there is always a sufficient amount of gel as a medium between the treatment head and the tissue during the entire radiofrequency treatment, effectively ensuring the continuity and stability of energy transmission.

[0023] (5) Safety and comfort: The radiofrequency therapy gel prepared in this application is made of biocompatible materials and contains no preservatives or other irritating additives. It can meet the long-term use needs of the vaginal mucosa and effectively improve the comfort of patients during use. Attached Figure Description

[0024] Figure 1 This is a comparison diagram of the radiofrequency therapy device gel prepared in Example 1 of this invention and the vaginal simulation solution. Figure 2 This is a diagram showing the mixed state of the gel for radiofrequency therapy prepared in Comparative Example 1 with vaginal simulation fluid in this invention; Figure 3 This refers to colposcopy images taken after treatment with the gel prepared in Example 1 using the radiofrequency therapy device in this invention. Figure 4 In this invention, colposcopy images were taken after treatment with the gel prepared in Comparative Example 1 using a radiofrequency therapy device. Figure 5 This is a graph showing the resistance change of the gel for radiofrequency therapy prepared in Example 1 of this invention at room temperature. Figure 6 This is a graph showing the change in resistance of the gel used in the radiofrequency therapy device prepared in Example 1 of this invention after heating. Figure 7 This is a graph showing the resistance change of the gel for radiofrequency therapy prepared in Example 2 of this invention at room temperature; Figure 8 This is a graph showing the change in resistance of the gel used in the radiofrequency therapy device prepared in Example 2 of this invention after heating. Figure 9 This is a graph showing the resistance change of the gel for radiofrequency therapy prepared in Example 3 of this invention at room temperature; Figure 10 This is a graph showing the change in resistance of the gel used in the radiofrequency therapy device prepared in Example 3 of this invention after heating. Figure 11 This is a graph showing the resistance change of the gel for radiofrequency therapy prepared in Example 4 of this invention at room temperature. Figure 12 This is a graph showing the change in resistance of the gel used in the radiofrequency therapy device prepared in Example 4 of this invention after heating. Figure 13 This is a diagram showing the gel fiber-drawing effect of the radiofrequency therapy device prepared in Example 5 of this invention; Figure 14 This is a graph showing the resistance change of the gel for radiofrequency therapy prepared in Example 5 of this invention at room temperature; Figure 15 This is a graph showing the change in resistance of the gel used in the radiofrequency therapy device prepared in Example 5 of this invention after heating. Figure 16 This is a graph showing the resistance change of the gel used in the radiofrequency therapy device prepared in Comparative Example 1 at room temperature in this invention. Figure 17 This is a graph showing the change in resistance of the radiofrequency therapy device prepared in Comparative Example 1 after heating with gel in this invention. Figure 18 This is a graph showing the resistance change of the gel used in the radiofrequency therapy device prepared in Comparative Example 2 at room temperature in this invention. Figure 19 This is a graph showing the change in resistance of the radiofrequency therapy device prepared in Comparative Example 2 after heating with gel. Figure 20 This is a graph showing the resistance change of the gel used in the radiofrequency therapy device prepared in Comparative Example 3 at room temperature in this invention. Figure 21 This is a graph showing the change in resistance of the radiofrequency therapy device prepared in Comparative Example 3 after heating with gel. Figure 22 This is a graph showing the resistance change of the gel used in the radiofrequency therapy device prepared in Comparative Example 4 at room temperature in this invention. Figure 23This is a graph showing the change in resistance of the radiofrequency therapy device prepared in Comparative Example 4 after heating with gel, as described in this invention. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] The following embodiments are by weight percentage; it should be noted that there are no special restrictions on the purchase manufacturers of all raw materials involved in this invention, and they include, for example: propylene glycol (CAS: 57-55-6), hydroxyethyl cellulose (CAS: 9004-62-0), glycerol (CAS: 56-81-5), citric acid (CAS: 72-92-9), polyethylene glycol-90M (brand name Dow POLYOXWSR301, molecular weight 9,000,000 Da), and other reagents not specifically mentioned are commercially available.

[0027] Example 1: A gel for vaginal radiofrequency therapy, the preparation method of which specifically includes the following steps: Step 1: (1) Add 3% propylene glycol to 28% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, and slowly add 0.9% hydroxyethyl cellulose (weight average molecular weight 1,000,000) while stirring, and stir for 35 minutes; then let stand or stir to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 12% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 55% glycerol, continue stirring at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.005% citric acid to the remaining purified water and stir for 5 minutes to obtain an aqueous citric acid solution. Add the solution to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0028] Example 2: A gel for vaginal radiofrequency therapy, the preparation method of which specifically includes the following steps: (1) Add 2.5% propylene glycol to 28% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, slowly add 1.5% hydroxyethyl cellulose (weight average molecular weight 1,000,000) while stirring, and stir for 35 minutes; then let stand or stir to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 15.5% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 40% glycerol, continue stirring at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.01% citric acid to the remaining purified water and stir for 5 minutes to obtain an aqueous citric acid solution. Add the solution to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0029] Example 3: A gel for vaginal radiofrequency therapy, the preparation method of which specifically includes the following steps: (1) Add 2.0% propylene glycol to 18% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, and slowly add 0.5% hydroxyethyl cellulose (weight average molecular weight 1,000,000) while stirring, and stir for 35 minutes; then let stand or stir to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 8% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 70% glycerol, continue stirring at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.001% citric acid to purified water and stir for 5 minutes to obtain an aqueous citric acid solution. Add the solution to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0030] Example 4: A gel for vaginal radiofrequency therapy, the preparation method of which specifically includes the following steps: Step 1: (1) Add 3% propylene glycol to 28% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, and slowly add 0.9% hydroxyethyl cellulose (weight average molecular weight 1,000,000) while stirring, and stir for 35 minutes; then let stand or stir to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 12% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 55% glycerol, continue stirring at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.01% citric acid to the remaining purified water and stir for 5 minutes to obtain an aqueous citric acid solution. Add the solution to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0031] Example 5: Further, based on Example 1, 0.1% polyethylene glycol-90M was added to prepare a gel for radiofrequency therapy devices, specifically including the following steps: Step 1: (1) Add 3% propylene glycol to 22% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, and slowly add 0.9% hydroxyethyl cellulose (weight average molecular weight 1,000,000) while stirring, and stir for 35 minutes; then let stand or stir to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 12% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 55% glycerol, continue stirring at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.1% polyethylene glycol-90M to 5% purified water and stir at 900 rpm until homogeneous. Then add it to the gel matrix phase and stir at 900 rpm for 35 minutes. Next, add 0.005% citric acid to the remaining purified water and stir for 5 minutes to obtain a citric acid aqueous solution. Add this solution to the gel matrix phase and add purified water to bring the solution to 100%. Continue stirring at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy devices.

[0032] Comparative Example 1: Based on Example 1, hydroxyethyl cellulose was replaced with carbomer, and citric acid was replaced with sodium hydroxide to prepare a gel for radiofrequency therapy devices; the rest remained the same as in Example 1, specifically including the following steps: Step 1: (1) Add 3% propylene glycol to 28% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, slowly add 0.9% carbomer while stirring, and stir for 35 minutes; then let it stand to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 12% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 55% glycerol, continue stirring at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.005% sodium hydroxide to the remaining purified water and stir for 5 minutes to obtain a sodium hydroxide aqueous solution. Then add it to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0033] Comparative Example 2: Based on Example 1, hydroxyethyl cellulose with a weight-average molecular weight of 1,000,000 was replaced with a weight-average molecular weight of 700,000 Da to prepare a gel for radiofrequency therapy devices. The rest of the steps remained the same as in Example 1, specifically including the following steps: Step 1: (1) Add 3% propylene glycol to 28% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, slowly add 0.9% hydroxyethyl cellulose (weight average molecular weight 700,000) while stirring, stir for 35 minutes; then let stand to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 12% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 55% glycerol, continue to stir at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.005% citric acid to the remaining purified water and stir for 5 minutes to obtain an aqueous citric acid solution. Add the solution to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0034] Comparative Example 3: Based on Example 1, the component content of the moisturizer was adjusted by adding 15% glycerin and 55% propylene glycol to prepare a gel for radiofrequency therapy devices. The rest remained the same as in Example 1. The specific steps are as follows: Step 1: (1) Add 11% propylene glycol to 28% purified water, stir at 200 rpm for 2 minutes at room temperature, then increase the speed to 1000 rpm, and slowly add 0.9% hydroxyethyl cellulose (weight average molecular weight 1,000,000) while stirring, and stir for 35 minutes; then let it stand to swell for 20 hours to obtain the pretreatment solution; (2) Slowly add 44% propylene glycol to the pretreatment solution, stir at 900 rpm for 35 minutes, then add 15% glycerol, continue to stir at 900 rpm for 35 minutes, homogenize for 10 minutes to obtain the gel matrix phase; Step 2: Add 0.005% citric acid to the remaining purified water and stir for 5 minutes to obtain an aqueous citric acid solution. Add the solution to the gel matrix phase and stir at 900 rpm for 25 minutes at room temperature. Defoam under vacuum to obtain the gel for radiofrequency therapy.

[0035] Comparative Example 4: Based on Example 1, the mass ratio of glycerin to propylene glycol in the formula was further reduced, and a carbomer gel system was used to prepare a gel for radiofrequency therapy devices. The specific steps are as follows: Step 1: Swell 0.5% carbomer in the body cavity by standing in 40% purified water for 8 hours. Then rinse the carbomer in batches with 30% purified water and pour it into the main pot. Stir at 7 rpm for 10 minutes at room temperature. Homogenize at 1500 rpm for 5 minutes under -0.1 MPa conditions, repeating the homogenization process 3 times. Add the pre-dissolved 3% glycerol and 3% propylene glycol mixture and stir at 7 rpm for 10 minutes to obtain the gel matrix phase. Step 2: Add the pre-dissolved 0.5% triethanolamine and the remaining purified water to the gel matrix phase in sequence, and stir at 7 rpm for 30 min to obtain the gel for radiofrequency therapy device.

[0036] Performance testing: Experiment 1: Physical stability test: 1. Prepare the test liquids: vaginal simulation solution, hydroxyethyl cellulose + vaginal simulation solution (ratio 5:5), hydroxyethyl cellulose + vaginal simulation solution (ratio 1:5), and carbomer system + vaginal simulation solution (ratio 1:5), labeled as 0155, 1155, 2155, and 3155 respectively. Heat the test liquids to 55℃ and observe the state of the test liquids respectively; 2. Mix the radiofrequency therapy device gel prepared in Comparative Example 1 with the vaginal simulation solution and observe the state of the gel after mixing.

[0037] Test Experiment 2: Electrical Stability: The gels prepared in Examples 1-5 and Comparative Examples 1-4 were heated at 1 MHz (the actual measured frequency was 1.0005 MHz due to instrument resolution limitations) at room temperature and 50 ℃ respectively. The resistance at room temperature and the resistance after heating were observed to characterize the changes in their electrical properties.

[0038] Results and conclusions: 1. From Figure 1 It can be seen that after heating the prepared samples to 55℃, the vaginal simulated solution itself remained clear. Meanwhile, the hydroxyethyl cellulose + vaginal simulated solution (volume ratio set to 5:5) and hydroxyethyl cellulose + vaginal simulated solution (volume ratio set to 1:5) also remained clear. However, the carbomer system + vaginal simulated solution (1:5 ratio) gel appeared as a white, hazy substance. Figure 2 As can be seen from the above, after the gel for radiofrequency therapy prepared in Comparative Example 1 was mixed with the vaginal simulation solution, the mixture showed obvious stratification and flocculation, indicating that the physical properties of the gel for radiofrequency therapy prepared in the carbomer system are unstable, which limits its therapeutic prospects in clinical scenarios. pass Figure 13It can be seen that the gel prepared by adding a small amount of the stringing agent polyethylene glycol-90M in Example 5 does not exhibit flocculation problems similar to those of the carbomer system when mixed with the vaginal simulation solution. At the same time, the stringing length can reach 10 mm or more. This phenomenon further indicates that the gel can enhance clinical operability and improve the patient's user experience during use.

[0039] Furthermore, the radiofrequency therapy devices prepared in Example 1 and Comparative Example 1 were used for clinical treatment with gel. Figure 3 It can be seen that after rinsing the vagina with saline solution and confirming the vaginal environment with a colposcope before radiofrequency treatment, no white flocculent material was generated or left in the vagina after treatment with the radiofrequency treatment gel prepared in Example 1; however, white flocculent material appeared during the treatment process when using the radiofrequency treatment gel prepared in Comparative Example 1. Figure 4 Even after treatment, white residue may remain in the vagina. Therefore, compared to carbomer gels, hydroxyethyl cellulose gels have superior temperature stability and clinical cleanliness, effectively avoiding potential clinical risks caused by gel flocculation and residue, and are more suitable for vaginal-related clinical treatment scenarios.

[0040] 2. Through Figures 5-6 It can be seen that the gel for radiofrequency therapy obtained in Example 1, at room temperature and with a radiofrequency frequency of 1MHz, had an impedance of 132.01KΩ. After heating to 50℃, at the same frequency, the gel impedance was measured to be 129.48KΩ. This shows that the electrical properties of the gel decreased by 1.92% before and after heating. Using the same testing procedure, the gel for radiofrequency therapy obtained in Example 2 was also measured to have an impedance of... Figures 7-8 As shown, at room temperature, the impedance is 111.81 KΩ, and after heating to 50°C, the impedance is 110.48 KΩ, with the electrical properties of the gel decreasing by 1.19% before and after heating. The gel for radiofrequency therapy obtained in Example 3, as shown in Figures 9 and 10, has an impedance of 193.95 KΩ at room temperature, and after heating to 50°C, the impedance is 193.8 KΩ, with the electrical properties of the gel decreasing by 0.08% before and after heating. Figures 11-12 It can be seen that the gel obtained in Example 4, at room temperature with a radio frequency of 1MHz, had an impedance of 129.79KΩ. After heating to 50℃, at the same frequency, the gel's impedance decreased to 127.04KΩ. Comparing the two impedance data, it can be seen that the electrical properties of the gel decreased by 2.12% before and after heating. Figures 14-15As can be seen, in Example 5, with the addition of the fiber-drawing agent polyethylene glycol-90M, the gel impedance was measured to be 147.13 KΩ at room temperature and with the radio frequency set to 1 MHz. After heating to 50°C, the gel impedance was measured to be 144.23 KΩ at the same frequency. It can be seen that the electrical properties of the gel decreased by 1.97% before and after heating. However, in comparison Figures 16-17 The impedance changes show that the gel for radiofrequency therapy obtained in Comparative Example 1, at room temperature with a radiofrequency frequency of 1MHz, has an impedance of 97.765KΩ. After heating to 50℃, its impedance drops significantly to 59.327KΩ at the same frequency. The electrical properties of the gel obtained in Comparative Example 1 decreased significantly by 39.32% before and after heating. Figures 18-19 As can be seen, the gel obtained in Comparative Example 2, at room temperature with a radio frequency of 1MHz, had an impedance of 102.7KΩ. After heating to 50℃, the impedance of the gel decreased to 84.65KΩ at the same frequency. Comparing the impedance data of the two, it can be seen that the electrical properties of the gel decreased by 17.58% before and after heating. Figures 20-21 As can be seen, the gel obtained in Comparative Example 3, at room temperature with a radio frequency of 1MHz, had an impedance of 76.58KΩ. After heating to 50℃, the impedance of the gel decreased to 53.72KΩ at the same frequency. Comparing the impedance data of the two, it can be seen that the electrical properties of the gel decreased by 29.85% before and after heating. Figures 20-21 It can be seen that, Figures 22-23 As can be seen, the gel obtained in Comparative Example 4, at room temperature with a radio frequency of 1 MHz, had an impedance of 3.20 KΩ. After heating to 50°C, at the same frequency, the impedance of the gel decreased to 2.19 KΩ. Comparing the impedance data of the two examples, it can be seen that the electrical properties of the gel decreased by 31.6% before and after heating. In summary, it can be seen that the gel prepared in Example 1 showed no significant change in impedance before and after heating. With the addition of a fiber-drawing agent, the impedance change was still controlled within 5%, which is far better than Comparative Examples 1-4. This indicates that the gel still has stable electrical properties under radio frequency heating, which can meet the requirements for clinical use.

[0041] 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 gel for vaginal radiofrequency therapy, characterized in that: The gel for the radiofrequency therapy device comprises the following raw materials, by weight percentage: 0.5-1.5% nonionic cellulose ether gel matrix, 50-88% moisturizer, 0.001-0.01% citric acid; the remainder is water.

2. The gel for vaginal radiofrequency therapy according to claim 1, characterized in that: The nonionic cellulose ether gel matrix is ​​hydroxyethyl cellulose; the weight-average molecular weight of the hydroxyethyl cellulose is 720,000~1,300,000 Da.

3. The gel for vaginal radiofrequency therapy according to claim 2, characterized in that: The moisturizer comprises (10~18): (40~70) propylene glycol and glycerin.

4. The gel for vaginal radiofrequency therapy according to claim 1, characterized in that: The pH of the gel used in the radiofrequency therapy device is 3.8~6.

5. The gel for vaginal radiofrequency therapy according to claim 1, characterized in that: The preparation method of the gel for the radiofrequency therapy device includes the following steps: Step 1: Add some of the humectant to the water, mix well, then add the nonionic cellulose ether gel matrix, stir well, let stand or stir to swell, and obtain the gel matrix phase; Step 2: Add the remaining moisturizer to the gel matrix phase in sequence, mix and homogenize, then continue to add the mixed solution of citric acid and water, stir for 20-30 minutes at room temperature, and defoam under vacuum to obtain the gel for radiofrequency therapy device.

6. The gel for vaginal radiofrequency therapy according to claim 5, characterized in that: The time for standing or stirring to swell is 18-24 hours; the time for mixing and homogenizing is 8-12 minutes.

7. The gel for vaginal radiofrequency therapy according to claim 1, characterized in that: The raw materials of the gel used in the radiofrequency therapy device also include 0.03~0.2% of a fiber-drawing agent.

8. The gel for vaginal radiofrequency therapy according to claim 7, characterized in that: The fiber-drawing agent is polyethylene glycol-90M.

9. The gel for vaginal radiofrequency therapy according to claim 7, characterized in that: The preparation method of the gel for the radiofrequency therapy device is as follows: Step 1: Add a portion of the moisturizer to water, mix evenly, and then add non-ionic cellulose ether gel matrix. Stir evenly, let stand or stir to swell, and obtain the gel matrix phase. Step 2: Add the mixture of the drawing agent and water, and the remaining moisturizer to the gel matrix phase in sequence, mix and homogenize, then continue to add the mixture of citric acid and water. Stir at room temperature for 20-30 minutes, then defoam under vacuum to obtain the gel for radiofrequency therapy devices.

Images