Progesterone vaginal sustained-release gel and preparation method thereof

Abstract

The invention relates to the technical field of pharmaceutical preparations, in particular to progesterone vaginal sustained-release gel and a preparation method thereof, and the preparation method comprises the following steps: S100, raw material pretreatment; s200, preparing a hydrogel; s300, preparing an oil phase system; and S400, gel forming is carried out. Through accurate preparation steps and strict quality control, it is ensured that a uniform porous network structure is presented in the gel and progesterone nanocrystals are uniformly distributed in the gel, so that slow and continuous release of the medicine is achieved, in addition, the adhesion performance of the gel is optimized, the gel can be retained in the vagina for a long time, and the effect that the progesterone nanocrystals are uniformly distributed in the gel is achieved. The local action effect of the medicine is further enhanced, the curative effect of the medicine is improved, the administration frequency is reduced, and greater convenience and comfort are brought to patients.

Description

Technical Field

[0001] The invention relates to the technical field of pharmaceutical preparations, in particular to a progesterone vaginal sustained-release gel and a preparation method thereof. Background Art

[0002] Currently, progesterone vaginal preparations are widely used in the field of gynecology, but existing progesterone vaginal preparations still have some shortcomings.

[0003] First, the stability of drug release is poor, which often leads to too fast or too slow drug release in the body, making it difficult to meet clinical needs. This is mainly due to the fact that the preparation process of the preparation is not sophisticated enough to form a uniform and stable release system. Secondly, the bioavailability of existing preparations needs to be improved, and the drug's retention time in the vagina and local effect are not ideal, which affects the therapeutic effect.

[0004] Therefore, a novel method for preparing a progesterone vaginal sustained-release gel is needed to solve the above problems and improve the stability and bioavailability of drug release. Summary of the invention

[0005] Technical issues solved

[0006] In view of the above-mentioned shortcomings of the prior art, the present invention provides a progesterone vaginal sustained-release gel and a preparation method thereof. The present invention ensures that the interior of the gel presents a uniform porous network structure through precise preparation steps and strict quality control, and progesterone nanocrystals are uniformly distributed therein, thereby achieving slow and sustained release of the drug. In addition, the method also optimizes the adhesion properties of the gel, so that it can remain in the vagina for a long time, further enhancing the local effect of the drug, which not only improves the efficacy of the drug, but also reduces the frequency of administration, bringing greater convenience and comfort to patients.

[0007] Technical Solution

[0008] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A method for preparing a progesterone vaginal sustained-release gel, the method comprising the following steps:

[0010] S100, Raw material pretreatment:

[0011] S101, taking a natural plant extract composed of soy isoflavones and ginkgo flavonoids in a mass ratio of 3:2, dissolving it in an ethanol aqueous solution with a mass fraction of 75%, so that the mass concentration of the natural plant extract in the solution reaches 8%, stirring at 35° C. for 25 minutes, and then removing ethanol through a reduced pressure distillation device to obtain a concentrate;

[0012] S102, mixing polyethylene glycol and polylactic acid-co-glycolic acid copolymer with the concentrate in a mass ratio of 2.5:1, heating and melting at 55° C. under nitrogen protection, and stirring for 40 minutes until the two are fully mixed to obtain a mixture A;

[0013] S103, selecting an amphiphilic lipid material composed of dipalmitoylphosphatidylethanolamine and cholesterol in a mass ratio of 5:1, dissolving the material in chloroform to prepare a solution with a mass concentration of 18%, stirring the solution at room temperature for 12 minutes, evaporating the chloroform by a rotary evaporator under a reduced pressure of 0.08 MPa, allowing the lipid material to form a thin film on the container wall, and then drying the solution in a vacuum environment for 3 hours to obtain a lipid film;

[0014] S104, dissolving progesterone in a mixed solvent of acetone and water with a mass fraction of 55%, maintaining the mass concentration of progesterone in the solution at 12%, treating for 12 minutes under the conditions of an ultrasonic frequency of 25 kHz and a power of 150 W, and then preparing nanocrystals by a spray drying method using a spray drying device, wherein the air inlet temperature during spray drying is set to 135° C. and the air outlet temperature is set to 70° C., thereby obtaining progesterone nanocrystals with a particle size of 150 nm;

[0015] S200, hydrogel preparation:

[0016] S201, adding mixture A to purified water sterilized by ultraviolet light, with the mass ratio of mixture A to purified water being 1:12, and stirring at 1200 rpm for 18 minutes at 28° C. to form a uniform dispersion;

[0017] S202, slowly adding carbomer to the dispersion, with the mass ratio of carbomer to mixture A being 1:2.5, while reducing the stirring speed to 500 rpm, and continuing stirring for 25 minutes to obtain a preliminary colloidal mixture;

[0018] S203, then using a 0.55 mol / L borax-sodium hydroxide buffer to adjust the pH value of the colloidal mixture to 7.5, and using an online pH monitor to monitor in real time during the adjustment process. After the adjustment is completed, the mixture is transferred to a water bath heating device with a mechanical stirring function, first stirred at 42° C. at a speed of 250 rpm for 1.2 hours, then heated to 52° C., and continued to stir at this temperature for 2.5 hours until a stable hydrogel is formed;

[0019] S300, oil phase system preparation:

[0020] S301, adding the lipid film to medium chain triglycerides, the mass ratio of the lipid film to the medium chain triglycerides being 1:4, stirring at room temperature for 25 minutes by a stirring device to dissolve the lipid film in the medium chain triglycerides, and obtaining an oil phase solution;

[0021] S302, adding Tween 80 to the oil phase solution, the mass ratio of Tween 80 to the oil phase solution being 1:12, stirring at 35° C. for 12 minutes to uniformly disperse the Tween 80 in the oil phase solution to obtain a uniform oil phase system;

[0022] S400, gel forming:

[0023] S401, slowly dropping the oil phase system into the hydrogel at a dropping speed of 0.8 ml / s through a high-purity nitrogen supply system in a high-purity nitrogen protection atmosphere with a purity of more than 99.999%, maintaining the hydrogel temperature at 52° C. using a circulating water cooling device during the dropping process, and stirring at a speed of 150 rpm using a double-layer paddle stirring paddle, wherein the inner and outer blade angles of the double-layer paddle stirring paddle are 45° and 60° respectively, and the spacing between the inner and outer blades is 6 mm, and stirring is continued for 30 minutes after the dropping is completed;

[0024] S402, then, adding progesterone nanocrystals to the mixed system, the ratio of the total mass of the progesterone nanocrystals to the hydrogel and the oil phase system being 6.5:100, and stirring at 52° C. at a speed of 120 rpm for 20 minutes to uniformly disperse the progesterone nanocrystals;

[0025] S403, then heating the system to 70°C, the heating process is controlled by a programmed temperature control system, the heating rate is 1°C / min, stirring at 100 rpm for 5 hours at this temperature, and finally cooling the system naturally to room temperature;

[0026] S404. During the cooling process, the mixture was stirred at a speed of 50 rpm for 4 minutes every 30 minutes to prevent the gel from stratifying, thereby obtaining a progesterone vaginal sustained-release gel.

[0027] Furthermore, the vacuum distillation equipment in step S101 needs to be calibrated for vacuum and temperature before each use to ensure that the vacuum error is controlled within ±0.01MPa and the temperature error is within ±2°C. At the same time, the distillation device is cleaned and dried to prevent residual impurities from affecting subsequent reactions;

[0028] In step S102, the nitrogen flow rate and temperature stability are monitored by a nitrogen protection heating device to ensure that the nitrogen flow rate fluctuation does not exceed ±0.1 L / min and the temperature error is within ±1°C, so as to ensure the preparation quality of the mixture A;

[0029] In step S103, the sealing performance and vacuum system of the rotary evaporator must be checked before use to keep the vacuum degree between 0.05-0.1 MPa. During the evaporation process, the rotation speed must be controlled at 60 rpm and the temperature must be controlled at 35° C. to ensure uniform formation of the lipid film;

[0030] In step S104, before preparing nanocrystals, the spray drying equipment needs to adjust the spray pressure to 0.2MPa, the inlet temperature error to within ±5°C, and the outlet temperature error to within ±3°C. After preparation, the particle size distribution of the nanocrystals needs to be detected to ensure that the coefficient of variation of the particle size distribution is less than 20% and the crystal integrity rate reaches more than 90%.

[0031] Furthermore, the purified water treated by ultraviolet sterilization in step S201 needs to be tested for microbial content before use to ensure sterility;

[0032] In step S203, the online pH monitor is calibrated every 3 hours using a standard buffer solution to ensure that the pH measurement accuracy is within ±0.02 pH units;

[0033] In step S203, the temperature control system of the water bath heating device accurately controls the temperature so that the temperature fluctuation does not exceed ±0.5°C. The stirring paddle of the mechanical stirring device should be made of corrosion-resistant, non-shedding stainless steel. During the stirring process, the speed stability of the stirring paddle is monitored to ensure that the speed fluctuation does not exceed ±10rpm.

[0034] During the hydrogel formation process, samples are taken regularly to test the viscosity of the hydrogel. The viscosity should be between 12000-14000 mPa·s and the thixotropy should be maintained. If it does not meet the requirements, the preparation parameters are adjusted.

[0035] Furthermore, the medium chain triglycerides in step S301 need to be filtered before use, with a filtering accuracy of 0.3 μm to remove impurities;

[0036] In step S301, the stirring device must ensure stirring uniformity during the stirring process, and the degree of mixing uniformity is determined by detecting the refractive index of the oil phase solution, and the refractive index deviation is required to be no more than ±0.001;

[0037] In step S302, Tween 80 needs to be added slowly and the adding time is controlled within 8 minutes to prevent the local concentration from being too high and causing agglomeration;

[0038] After the oil phase system is prepared, its particle size distribution is detected by using a laser particle size analyzer to ensure that the particle size distribution is between 60-90nm and the distribution uniformity reaches more than 95%. If it does not meet the standards, the preparation process is readjusted.

[0039] Furthermore, in step S401, the high-purity nitrogen gas supply system is equipped with a high-precision flow controller to ensure that the flow control accuracy is within ±0.05L / minute, and a pressure sensor to ensure that the pressure fluctuation does not exceed ±0.03MPa;

[0040] In step S401, the double-layer paddle stirring paddle needs to be dynamically balanced before installation, and the installation angle needs to be accurately adjusted to ensure that the materials are mixed evenly and no bubbles are generated during the stirring process;

[0041] In step S403, the temperature sensor of the programmed temperature control system needs to be calibrated regularly, with the calibration error within ±0.5°C and the heating rate error within ±0.1°C / minute;

[0042] In step S404, during the cooling process, a temperature monitor is used to monitor the temperature change of the system to ensure that the temperature uniformity is within ±0.8°C. After cooling is completed, the gel is subjected to appearance inspection, drug content uniformity test and in vitro release test to ensure that all indicators meet the expected requirements. The drug content uniformity test adopts high performance liquid chromatography, and the in vitro release test adopts dialysis bag method, and the release medium is phosphate buffer with a pH of 4.5-5.5.

[0043] Furthermore, the preparation method also includes the following post-processing operations after gel formation:

[0044] The gel was refrigerated at -10°C for 18 hours in a sealed, sterile plastic container to prevent water evaporation and impurity contamination;

[0045] After the refrigeration, the gel was ground by a cryogenic grinder. The grinding medium of the grinder was zirconia ceramic balls with a ball diameter of 4 mm. The grinding speed was 600 rpm and the grinding time was 45 minutes, so that the particle size of the gel was reduced to 60-90 μm.

[0046] The ground gel was then mixed with a mixture of cross-linked sodium carboxymethyl cellulose and mannitol in a mass ratio of 1:2.5, with the amount of the mixture being 15% of the mass of the gel, and the mixing process was carried out at room temperature using a V-type mixer for 25 minutes;

[0047] Finally, the mixed material is loaded into a vaginal applicator sterilized with ethylene oxide. The applicator is made of medical-grade polypropylene, and the outlet of the applicator is designed to be conical to facilitate the extrusion of the gel and its distribution in the vagina.

[0048] Furthermore, during the entire preparation process:

[0049] The operating environment temperature is maintained at 22°C, the humidity is controlled at 40%, and the cleanliness reaches Class B standard;

[0050] The operation workshop is equipped with an air filtration system, a temperature and humidity control system, and an environmental monitoring system. The air filtration system has a filtration efficiency of more than 99.95% for dust particles larger than 0.5 μm. The monitoring parameters of the temperature and humidity control system and the environmental monitoring system include but are not limited to temperature, humidity, number of dust particles, and number of microbial colonies;

[0051] Operators must undergo strict procedures of changing clothes, washing hands, disinfection and air showering before entering the workshop. After entering the workshop, they must follow aseptic operation procedures to avoid contamination of products by personnel and the environment;

[0052] Establish a complete quality control system and keep detailed records of the raw material procurement, production process, quality inspection and finished product packaging of each batch of products. The records include but are not limited to raw material inspection reports, production equipment operating parameters, operator operation records, quality inspection original data and finished product packaging specifications. All records are kept in both electronic and paper documents for no less than one year after the product's expiration date, so that when quality problems occur in the product, the causes can be quickly traced and analyzed, and effective improvement measures can be taken.

[0053] Furthermore, the gel is composed of: 6.5% progesterone nanocrystals, 12% mixture of natural plant extract and polyethylene glycol-polylactic acid-glycolic acid copolymer, 4% lipid film of dipalmitoyl phosphatidylethanolamine and cholesterol, 18% medium chain triglyceride, 1.5% Tween 80, 4% carbomer, 45% purified water, and 15% mixture of cross-linked sodium carboxymethyl cellulose and mannitol;

[0054] The gel has a porous network structure with a pore size between 60-90nm. Nanocrystals are evenly distributed in the network structure. Its in vitro release curve has specific sustained-release characteristics. The release rate is 3%-4% in the initial 0-2 hours, and then enters a slow release stage. The cumulative release rate within 24 hours is 25%-28%, the cumulative release rate within 48 hours is 45%-48%, and the cumulative release rate within 72 hours reaches 65%-68%. Under the storage conditions of 2-8℃, light-proof and sealed, the shelf life can reach 24-36 months. The gel has certain adhesion properties in the vagina, and the adhesion force reaches 0.4-0.5N / cm 2 It can remain in the vagina for a certain period of time, which can be up to 48-72 hours, slowly releasing drugs and improving the bioavailability of drugs. It also has good biocompatibility and safety and has no obvious irritation to the vaginal mucosa.

[0055] Beneficial Effects

[0056] Compared with the known public technology, the technical solution provided by the present invention has the following beneficial effects:

[0057] 1. The present invention ensures that the final product has excellent stability and sustainability through the steps of raw material pretreatment, hydrogel preparation, oil phase system preparation and gel molding. In particular, the progesterone nanocrystals are prepared by spray drying, and the porosity and thixotropy of the hydrogel are precisely controlled, so that the drug can be released slowly and stably in the vagina. This sustained-release characteristic not only improves the utilization efficiency of the drug, but also reduces the frequency of medication for patients, thereby enhancing the comfort and compliance of patients.

[0058] 2. The double-layer paddle stirring paddle and programmed temperature control system used in the present invention ensure the uniformity and stability of the oil phase system and the hydrogel during the mixing process. This uniform mixing enables the progesterone nanocrystals to be evenly distributed in the porous network structure of the hydrogel, thereby optimizing the distribution of the drug in the vagina. In addition, by precisely controlling various parameters in the preparation process, such as temperature, stirring speed, pH value, etc., the bioavailability of the drug is further improved, allowing the drug to more effectively exert its therapeutic effect. DETAILED DESCRIPTION

[0059] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The present invention will be further described below in conjunction with the embodiments.

[0061] Example 1: Preparation of progesterone vaginal sustained-release gel:

[0062] 1. Raw material pretreatment:

[0063] Preparation of natural plant extract concentrates:

[0064] Accurately weigh a natural plant extract composed of soy isoflavones and ginkgo flavonoids in a mass ratio of 3:2, dissolve it in a 75% ethanol aqueous solution to make the mass concentration of the natural plant extract in the solution reach 8%, and stir at 35°C at a stable stirring speed for 25 minutes to ensure that the natural plant extract is fully dissolved.

[0065] Use a calibrated (vacuum degree error is controlled within ±0.01MPa, temperature error is within ±2°C) and cleaned and dried reduced pressure distillation equipment to remove ethanol. For example, after calibration, the actual vacuum degree is 0.08MPa (set value) ±0.01MPa, and the temperature is 35°C (set value) ±2°C to obtain a concentrate.

[0066] Preparation of mixture A:

[0067] According to the mass ratio of polyethylene glycol to polylactic acid-glycolic acid copolymer of 2.5:1, accurately weigh and mix with the above concentrate, heat to melt at 55°C under nitrogen protection (nitrogen flow fluctuation does not exceed ±0.1L / min, temperature error is within ±1°C, monitored by nitrogen protection heating device), and continue stirring for 40 minutes until the two are fully mixed to obtain mixture A.

[0068] Preparation of lipid films:

[0069] An amphiphilic lipid material composed of dipalmitoylphosphatidylethanolamine and cholesterol in a mass ratio of 5:1 was selected and dissolved in chloroform to prepare a solution with a mass concentration of 18%, and stirred at room temperature (25° C.) for 12 minutes.

[0070] Using a rotary evaporator (check the sealing performance and vacuum system before use to keep the vacuum degree between 0.05-0.1MPa, control the rotation speed at 60rpm and the temperature at 35°C during the evaporation process) to evaporate chloroform under the condition of reduced pressure to 0.08MPa, the lipid material forms a thin film on the container wall, and then dried under vacuum for 3 hours to obtain a lipid film. After testing, the thickness uniformity of the lipid film reached more than 95% (compared with the traditional preparation method, the thickness uniformity of the traditional method is about 85%).

[0071] Preparation of Progesterone Nanocrystals:

[0072] Progesterone was dissolved in a mixed solvent of acetone and water with a mass fraction of 55%, the mass concentration of progesterone in the solution was maintained at 12%, and the solution was treated for 12 minutes under the conditions of an ultrasonic frequency of 25 kHz and a power of 150 W. Then, nanocrystals were prepared by a spray drying method using a spray drying device (the spray pressure was adjusted to 0.2 MPa, the inlet air temperature error was within ±5° C., and the outlet air temperature error was within ±3° C. before preparation). During spray drying, the inlet air temperature was set to 135° C. and the outlet air temperature was set to 70° C., and progesterone nanocrystals with a particle size of 150 nm were obtained. After testing, the particle size distribution variation coefficient of the nanocrystals was 15% (less than 20%), and the crystal form integrity rate reached 92% (higher than 90%), while the particle size distribution variation coefficient of the nanocrystals obtained by the traditional preparation method was about 25%, and the crystal form integrity rate was about 80%.

[0073] 2. Hydrogel Preparation

[0074] Preparation of dispersion:

[0075] The mixture A was added into purified water which was sterilized by ultraviolet light (the microbial content was tested before use to ensure sterility) and whose mass ratio was 12 times that of the mixture A, and stirred at 1200 rpm for 18 minutes at 28°C to form a uniform dispersion.

[0076] Preparation of preliminary colloidal mixture:

[0077] Slowly add carbomer to the dispersion (the mass ratio of carbomer to mixture A is 1:2.5), and reduce the stirring speed to 500 rpm. Stirring is continued for 25 minutes to obtain a preliminary colloidal mixture. During the stirring process, samples are taken regularly to detect the viscosity of the colloidal mixture. The viscosity is required to be between 12000 and 14000 mPa·s and the thixotropy is good (the thixotropy recovery time is between 10 and 15 seconds as detected by a thixotrope, and the thixotropy recovery time of the colloid prepared by the traditional method is about 20 to 25 seconds).

[0078] Hydrogel formation:

[0079] The pH value of the colloidal mixture was adjusted to 7.5 using a 0.55 mol / L borax-sodium hydroxide buffer solution. During the adjustment process, an online pH monitor was used (calibrated every 3 hours, using a standard buffer solution to ensure that the pH measurement accuracy was within ±0.02 pH units) for real-time monitoring. After the adjustment was completed, the mixture was transferred to a water bath heating device with a mechanical stirring function (the temperature control system accurately controlled the temperature so that the temperature fluctuation did not exceed ±0.5°C. The stirring paddle was made of corrosion-resistant, non-shedding stainless steel. The speed stability of the stirring paddle was monitored during the stirring process to ensure that the speed fluctuation did not exceed ±10 rpm). The mixture was first stirred at 42°C at a speed of 250 rpm for 1.2 hours, then heated to 52°C, and stirred at this temperature for 2.5 hours until a stable hydrogel was formed. The porosity of the hydrogel was tested to be 45%-50% (compared with traditional hydrogels, the porosity was increased by 10%-15%).

[0080] 3. Preparation of oil phase system:

[0081] Preparation of oil phase solution:

[0082] The lipid film was added to medium-chain triglycerides that had been filtered through 0.3 μm (the mass ratio of the lipid film to the medium-chain triglycerides was 1:4), and stirred at room temperature for 25 minutes using a stirring device to dissolve the lipid film in the medium-chain triglycerides to obtain an oil phase solution. The degree of mixing uniformity was determined by detecting the refractive index of the oil phase solution, and the refractive index deviation was required to be no more than ±0.001 (the refractive index deviation of the oil phase solution prepared by the traditional method was approximately ±0.003).

[0083] Preparation of uniform oil phase system:

[0084] Slowly drop Tween 80 into the oil phase solution (the mass ratio of Tween 80 to the oil phase solution is 1:12, and the dropping time is controlled within 8 minutes), and stir at 35°C for 12 minutes to evenly disperse Tween 80 in the oil phase solution to obtain a uniform oil phase system. The particle size distribution is detected by a laser particle size analyzer to ensure that the particle size distribution is between 60-90nm and the distribution uniformity reaches more than 95% (the particle size distribution of the oil phase system prepared by the traditional method is between 80-120nm, and the uniformity is about 85%).

[0085] 4. Gel forming:

[0086] Mixing of oil phase system and hydrogel:

[0087] Through the high-purity nitrogen supply system (equipped with a high-precision flow controller to ensure that the flow control accuracy is within ±0.05L / minute, and a pressure sensor to ensure that the pressure fluctuation does not exceed ±0.03MPa), the oil phase system is slowly added to the hydrogel at a dropping rate of 0.8ml / second in a high-purity nitrogen protective atmosphere with a purity of more than 99.999%. During the dropping process, a circulating water cooling device is used to maintain the hydrogel temperature at 52°C. At the same time, a double-layer paddle stirring paddle (installed for forward motion balance test, the installation angle is precisely adjusted, the inner and outer blade angles are 45° and 60° respectively, and the inner and outer blade spacing is 6mm) is used to stir at a speed of 150rpm. After the addition is completed, stirring is continued for 30 minutes.

[0088] Addition and dispersion of progesterone nanocrystals:

[0089] The progesterone nanocrystals were added into the mixed system (the ratio of the total mass of the progesterone nanocrystals to the hydrogel and the oil phase system was 6.5:100), and the mixture was stirred at 120 rpm for 20 minutes at 52° C. to uniformly disperse the progesterone nanocrystals.

[0090] Heating curing and cooling:

[0091] The system was heated to 70°C, and a programmed temperature control system was used during the heating process (the temperature sensor was calibrated regularly, the calibration error was within ±0.5°C, and the heating rate error was within ±0.1°C / minute). The heating rate was 1°C / minute, and the mixture was stirred at 100 rpm for 5 hours at this temperature. Finally, the system was naturally cooled to room temperature. During the cooling process, the mixture was stirred at 50 rpm for 4 minutes every 30 minutes to prevent gel stratification. During the cooling process, a temperature monitor was used to monitor the temperature change of the system to ensure that the temperature uniformity was within ±0.8°C. After cooling, the gel was inspected for appearance (no bubbles, no cracks, and uniform texture), drug content uniformity (using high performance liquid chromatography, content uniformity A+1.80S≤15.0), and in vitro release test (using a dialysis bag method, the release medium was a phosphate buffer solution with a pH of 4.5-5.5, and the release results are shown in the following table).

[0092] Comparison of in vitro release test results:

[0093]

[0094]

[0095] Example 2: Post-treatment of gel after forming

[0096] Refrigeration:

[0097] The prepared gel was placed in a low temperature environment of -10°C for 18 hours. The refrigeration process was carried out in a sealed, sterile plastic container to prevent water evaporation and impurity contamination.

[0098] Grinding treatment:

[0099] After the refrigeration, the gel was ground by a low-temperature grinder (the grinding medium was zirconia ceramic balls with a ball diameter of 4 mm, the grinding speed was 600 rpm, and the grinding time was 45 minutes) to reduce the particle size of the gel to 60-90 μm (the uniformity of the particle size distribution after grinding reached more than 90%, while the uniformity of the particle size distribution by the traditional grinding method was about 75%).

[0100] Mixing and Packaging:

[0101] The ground gel was then mixed with a mixture of cross-linked sodium carboxymethyl cellulose and mannitol in a mass ratio of 1:2.5 (the amount of the mixture was 15% of the mass of the gel, the mixing process was carried out at room temperature, a V-type mixer was used, and the mixing time was 25 minutes), and finally the mixed material was loaded into a vaginal applicator sterilized with ethylene oxide (the material of the applicator was medical grade polypropylene, and the outlet of the applicator was designed to be conical).

[0102] Example 3: Production environment and quality control

[0103] Production environment control:

[0104] The entire preparation process is carried out in a workshop with an operating environment temperature maintained at 22°C, humidity controlled at 40%, and cleanliness reaching Class B standards. The operating workshop is equipped with an air filtration system (with a filtration efficiency of more than 99.95% for dust particles larger than 0.5 μm), a temperature and humidity adjustment system, and an environmental monitoring system (monitoring parameters include but are not limited to temperature, humidity, number of dust particles, and number of microbial colonies).

[0105] Personnel operating specifications:

[0106] Operators must undergo strict changing of clothes, hand washing, disinfection and air shower procedures before entering the workshop. After entering the workshop, they must follow aseptic operating procedures to avoid contamination of the product by personnel and the environment.

[0107] Quality Control System:

[0108] A sound quality control system has been established to keep detailed records of the raw material procurement, production process, quality inspection and finished product packaging of each batch of products. The records include but are not limited to raw material inspection reports, production equipment operating parameters, operator operation records, quality inspection original data and finished product packaging specifications. All records are kept in both electronic and paper documents for a period of no less than one year after the product's expiration date. Through this quality control system, the defective rate of products is controlled within 2% (the defective rate of traditional production methods is about 5%).

[0109] Example 4: Product performance testing

[0110] Gel internal structure detection:

[0111] The internal structure of the gel was observed using a scanning electron microscope, and the results showed that it presented a porous network structure with pore sizes ranging from 60-90nm, and nanocrystals were evenly distributed in the network structure.

[0112] Drug release characteristics testing:

[0113] According to the above-mentioned in vitro release test method, the progesterone vaginal sustained-release gel of the present invention was tested for drug release characteristics, and the results showed that its release rate was 3%-4% within 0-2 hours, and then entered the slow release stage. The cumulative release rate within 24 hours was 25%-28%, the cumulative release rate within 48 hours was 45%-48%, and the cumulative release rate within 72 hours reached 65%-68%, which can achieve slow release of the drug.

[0114] Adhesion performance test:

[0115] The adhesion of the gel to the vaginal mucosa was measured using a texture analyzer, and the results showed that the adhesion reached 0.4-0.5N / cm 2 , can remain in the vagina for a certain period of time, the retention time can be up to 48-72 hours.

[0116] Biocompatibility and safety testing:

[0117] Through biocompatibility tests such as cytotoxicity test and skin irritation test, the results showed that the gel has no obvious irritation to the vaginal mucosa and has good biocompatibility and safety.

[0118] Example 5: Shelf Life Test

[0119] The progesterone vaginal sustained-release gel of the present invention is stored at 2-8° C., protected from light, and sealed, and its appearance, drug content, release rate and other indicators are regularly tested. The results show that within 24-36 months, all indicators of the product meet the quality requirements, indicating that its shelf life can reach 24-36 months.

[0120] It can be seen from the above embodiments that the method for preparing the progesterone vaginal sustained-release gel of the present invention uses precise process control and quality monitoring in each link such as raw material pretreatment, hydrogel preparation, oil phase system preparation, gel molding and post-processing, thereby ensuring the high quality and performance stability of the product, and has significant advantages in terms of drug sustained release, adhesion performance, biocompatibility, etc., and the production process is standardized and controllable, and the quality is stable and reliable.

[0121] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements will not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a progesterone vaginal sustained-release gel, characterized in that: The preparation method comprises the following steps: S100, raw material pretreatment: S101, taking a natural plant extract composed of soy isoflavones and ginkgo flavonoids in a mass ratio of 3:2, dissolving it in an ethanol aqueous solution with a mass fraction of 75%, so that the mass concentration of the natural plant extract in the solution reaches 8%, stirring at 35° C. for 25 minutes, and then removing ethanol through a reduced pressure distillation device to obtain a concentrate; S102, mixing polyethylene glycol and polylactic acid-glycolic acid copolymer with the concentrate in a mass ratio of 2.5:1, heating and melting at 55° C. under nitrogen protection, and stirring for 40 minutes until the two are fully mixed to obtain a mixture A; S103, selecting an amphiphilic lipid material composed of dipalmitoylphosphatidylethanolamine and cholesterol in a mass ratio of 5:1, dissolving the material in chloroform to prepare a solution with a mass concentration of 18%, stirring the solution at room temperature for 12 minutes, evaporating the chloroform by a rotary evaporator under a condition of reduced pressure to 0.08 MPa, allowing the lipid material to form a thin film on the container wall, and then drying the solution in a vacuum environment for 3 hours to obtain a lipid film; S104, dissolving progesterone in a mixed solvent of acetone and water with a mass fraction of 55%, maintaining the mass concentration of progesterone in the solution at 12%, treating for 12 minutes under the conditions of an ultrasonic frequency of 25 kHz and a power of 150 W, and then preparing nanocrystals by a spray drying method using a spray drying device, wherein the air inlet temperature during spray drying is set to 135° C. and the air outlet temperature is set to 70° C., thereby obtaining progesterone nanocrystals with a particle size of 150 nm; S200, hydrogel preparation: S201, adding mixture A to purified water sterilized by ultraviolet light, with the mass ratio of mixture A to purified water being 1:12, and stirring at 1200 rpm for 18 minutes at 28° C. to form a uniform dispersion; S202, slowly adding carbomer to the dispersion, with the mass ratio of carbomer to mixture A being 1:2.5, while reducing the stirring speed to 500 rpm, and continuing stirring for 25 minutes to obtain a preliminary colloidal mixture; S203, then using a 0.55 mol / L borax-sodium hydroxide buffer to adjust the pH value of the colloidal mixture to 7.5, and using an online pH monitor to monitor in real time during the adjustment process. After the adjustment is completed, the mixture is transferred to a water bath heating device with a mechanical stirring function, first stirred at 42° C. at a speed of 250 rpm for 1.2 hours, then heated to 52° C., and continued to stir at this temperature for 2.5 hours until a stable hydrogel is formed; S300, oil phase system preparation: S301, adding the lipid film to medium chain triglycerides, wherein the mass ratio of the lipid film to the medium chain triglycerides is 1:4, and stirring at room temperature for 25 minutes by a stirring device to dissolve the lipid film in the medium chain triglycerides to obtain an oil phase solution; S302, adding Tween 80 to the oil phase solution, the mass ratio of Tween 80 to the oil phase solution being 1:12, stirring at 35° C. for 12 minutes to uniformly disperse Tween 80 in the oil phase solution to obtain a uniform oil phase system; S400, gel forming: S401, slowly dropping the oil phase system into the hydrogel at a dropping speed of 0.8 ml / s through a high-purity nitrogen supply system in a high-purity nitrogen protection atmosphere with a purity of more than 99.999%, maintaining the hydrogel temperature at 52° C. using a circulating water cooling device during the dropping process, and stirring at a speed of 150 rpm using a double-layer paddle stirring paddle, wherein the inner and outer blade angles of the double-layer paddle stirring paddle are 45° and 60° respectively, and the spacing between the inner and outer blades is 6 mm, and stirring is continued for 30 minutes after the dropping is completed; S402, then, adding progesterone nanocrystals to the mixed system, the ratio of the total mass of the progesterone nanocrystals to the hydrogel and the oil phase system being 6.5:100, and stirring at 52° C. at a speed of 120 rpm for 20 minutes to uniformly disperse the progesterone nanocrystals; S403, then heating the system to 70°C, the heating process is controlled by a programmed temperature control system, the heating rate is 1°C / min, stirring at 100 rpm for 5 hours at this temperature, and finally cooling the system naturally to room temperature; S404. During the cooling process, the mixture was stirred at a speed of 50 rpm for 4 minutes every 30 minutes to prevent the gel from stratifying, thereby obtaining a progesterone vaginal sustained-release gel.

2. The method for preparing progesterone vaginal sustained-release gel according to claim 1, characterized in that: In step S101, the vacuum distillation equipment must be calibrated for vacuum and temperature before each use to ensure that the vacuum error is within ±0.01 MPa and the temperature error is within ±2°C. At the same time, the distillation device is cleaned and dried; In step S102, the nitrogen flow rate and temperature stability are monitored by a nitrogen protection heating device to ensure that the nitrogen flow rate fluctuation does not exceed ±0.1 L / min and the temperature error is within ±1°C; In step S103, the sealing performance and vacuum system of the rotary evaporator must be checked before use to keep the vacuum degree between 0.05-0.1 MPa. During the evaporation process, the rotation speed must be controlled at 60 rpm and the temperature must be controlled at 35°C. In step S104, before preparing nanocrystals, the spray drying equipment needs to adjust the spray pressure to 0.2MPa, the inlet temperature error to within ±5°C, and the outlet temperature error to within ±3°C. After preparation, the particle size distribution of the nanocrystals needs to be detected to ensure that the coefficient of variation of the particle size distribution is less than 20% and the crystal integrity rate reaches more than 90%.

3. The method for preparing progesterone vaginal sustained-release gel according to claim 1, characterized in that: The purified water sterilized by ultraviolet light in step S201 needs to be tested for microbial content before use to ensure sterility; In step S203, the online pH monitor is calibrated every 3 hours using a standard buffer solution to ensure that the pH measurement accuracy is within ±0.02 pH units; In step S203, the temperature control system of the water bath heating device accurately controls the temperature so that the temperature fluctuation does not exceed ±0.5°C. The stirring paddle of the mechanical stirring device should be made of corrosion-resistant, non-shedding stainless steel. During the stirring process, the speed stability of the stirring paddle is monitored to ensure that the speed fluctuation does not exceed ±10rpm. During the hydrogel formation process, samples are taken regularly to test the viscosity of the hydrogel. The viscosity should be between 12000-14000 mPa·s and the thixotropy should be maintained. If it does not meet the requirements, the preparation parameters are adjusted.

4. The method for preparing progesterone vaginal sustained-release gel according to claim 1, characterized in that: The medium chain triglycerides in step S301 need to be filtered before use, and the filtering accuracy is 0.3 μm; In step S301, the stirring device must ensure stirring uniformity during the stirring process, and the degree of mixing uniformity is determined by detecting the refractive index of the oil phase solution, and the refractive index deviation is required to be no more than ±0.001; In step S302, Tween 80 needs to be added slowly and the adding time is controlled within 8 minutes; After the oil phase system is prepared, its particle size distribution is detected by using a laser particle size analyzer to ensure that the particle size distribution is between 60-90nm and the distribution uniformity reaches more than 95%. If it does not meet the standards, the preparation process is readjusted.

5. The method for preparing progesterone vaginal sustained-release gel according to claim 1, characterized in that: In step S401, the high-purity nitrogen gas supply system is equipped with a high-precision flow controller to ensure that the flow control accuracy is within ±0.05L / minute, and a pressure sensor to ensure that the pressure fluctuation does not exceed ±0.03MPa; In step S401, the double-layer paddle stirring paddle needs to be dynamically balanced before installation, and the installation angle needs to be accurately adjusted to ensure that the materials are mixed evenly and no bubbles are generated during the stirring process; In step S403, the temperature sensor of the programmed temperature control system needs to be calibrated regularly, with the calibration error within ±0.5°C and the heating rate error within ±0.1°C / minute; In step S404, during the cooling process, a temperature monitor is used to monitor the temperature change of the system to ensure that the temperature uniformity is within ±0.8°C. After cooling is completed, the gel is subjected to appearance inspection, drug content uniformity test and in vitro release test to ensure that all indicators meet the expected requirements. The drug content uniformity test adopts high performance liquid chromatography, and the in vitro release test adopts dialysis bag method, and the release medium is phosphate buffer with a pH of 4.5-5.

5.

6. The method for preparing progesterone vaginal sustained-release gel according to claim 1, characterized in that: The preparation method also includes the following post-processing operations after gel formation: The gel was refrigerated at -10°C for 18 hours in a sealed, sterile plastic container to prevent water evaporation and impurity contamination; After the refrigeration, the gel was ground by a cryogenic grinder. The grinding medium of the grinder was zirconia ceramic balls with a ball diameter of 4 mm. The grinding speed was 600 rpm and the grinding time was 45 minutes, so that the particle size of the gel was reduced to 60-90 μm. The ground gel was then mixed with a mixture of cross-linked sodium carboxymethyl cellulose and mannitol in a mass ratio of 1:2.5, with the amount of the mixture being 15% of the gel mass, and the mixing process was carried out at room temperature using a V-type mixer for 25 minutes; Finally, the mixed materials are loaded into a vaginal applicator sterilized with ethylene oxide. The applicator is made of medical-grade polypropylene, and the outlet of the applicator is designed to be conical.

7. The method for preparing the progesterone vaginal sustained-release gel according to any one of claims 1 to 6, characterized in that: Throughout the preparation process: The operating environment temperature is maintained at 22°C, the humidity is controlled at 40%, and the cleanliness reaches Class B standard; The operation workshop is equipped with an air filtration system, a temperature and humidity control system, and an environmental monitoring system. The air filtration system has a filtration efficiency of more than 99.95% for dust particles larger than 0.5 μm. The monitoring parameters of the temperature and humidity control system and the environmental monitoring system include but are not limited to temperature, humidity, number of dust particles, and number of microbial colonies; Operators must undergo strict procedures of changing clothes, washing hands, disinfection and air showering before entering the workshop. After entering the workshop, they must follow aseptic operation procedures to avoid contamination of products by personnel and the environment; A sound quality control system shall be established to keep detailed records of the raw material procurement, production process, quality inspection and finished product packaging of each batch of products. The records shall include but not be limited to raw material inspection reports, production equipment operating parameters, operator operation records, quality inspection original data and finished product packaging specifications. All records shall be kept in both electronic and paper documents for a period of no less than one year after the product's expiration date.

8. A progesterone vaginal sustained-release gel obtained by the method for preparing the progesterone vaginal sustained-release gel according to any one of claims 1 to 7, characterized in that: The gel is composed of 6.5% progesterone nanocrystals, 12% natural plant extract and polyethylene glycol-polylactic acid-glycolic acid copolymer mixture, 4% dipalmitoyl phosphatidylethanolamine and cholesterol combined lipid film, 18% medium chain triglyceride, 1.5% Tween 80, 4% carbomer, 45% purified water, and 15% cross-linked sodium carboxymethyl cellulose and mannitol mixture. The gel has a porous network structure with a pore size between 60-90nm. Nanocrystals are evenly distributed in the network structure. Its in vitro release curve has specific sustained-release characteristics. The release rate is 3%-4% in the initial 0-2 hours, and then enters a slow release stage. The cumulative release rate within 24 hours is 25%-28%, the cumulative release rate within 48 hours is 45%-48%, and the cumulative release rate within 72 hours reaches 65%-68%.

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