Vacuum freeze drying method of 0.25 g ganciclovir for injection

Abstract

The invention belongs to the technical field of vacuum freeze drying, and particularly relates to a vacuum freeze drying method of 0.25 g ganciclovir for injection, which comprises the following steps: sequentially carrying out pre-freezing, staged temperature-controlled sublimation drying, temperature-controlled desorption drying, nitrogen charging and plug pressing on ganciclovir injection to obtain a ganciclovir freeze-dried preparation. According to the invention, an optimal freeze-drying one-time drying path is designed, a technical route of staged temperature control sublimation drying is adopted under vacuum, efficient freeze-drying of a low-collapse-temperature product is realized, the whole average total freeze-drying time is shortened to be less than 48 hours on the basis of ensuring the product quality, and the prepared freeze-drying preparation can be quickly redissolved and is free of toxic and side effects. The water content of the freeze-dried product is controlled to be less than 3.0%, and the appearance of the freeze-dried product shows complete white loose blocks.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vacuum freeze-drying, and particularly relates to a vacuum freeze-drying method of 0.25 g ganciclovir for injection. BACKGROUND

[0002] Viruses are widely spread, and the diseases caused by viruses are one of the most common infectious diseases in the world. The clinical symptoms and treatment schemes of viral infections are significantly different due to the virus types and individual differences of infected persons. Among them, cytomegalovirus is a common human herpes virus with a high infection rate in the population, and it is easy to cause complications in persons with low immune function, and can even endanger life in severe cases. Ganciclovir has become the main clinical treatment for cytomegalovirus due to its clear anti-cytomegalovirus effect, good bioavailability and long action time.

[0003] Ganciclovir, also known as 9-[[2-hydroxy-1-(hydroxymethyl)ethoxy]methyl] guanine, has a molecular formula of C9H 13 N5O4 and a structural formula of:

[0004] Ganciclovir is a classic anti-DNA virus drug, and its mechanism of action is to block viral replication by inhibiting viral DNA synthesis. It has inhibitory activity on herpes viruses and other common DNA viruses, and can be used clinically to treat cytomegalovirus infection, infectious mononucleosis, herpes zoster and varicella.

[0005] The clinical use of ganciclovir is mainly by injection, but the glycosidic bond in its molecular structure is prone to hydrolysis in a liquid state. Factors such as temperature, pH value and light can accelerate this process, and decomposition can lead to loss of efficacy, so ganciclovir injection is not easy to store for a long time. The freeze-drying process removes water in ganciclovir injection liquid by sublimation at extremely low temperature, forms a stable solid state of the drug, protects the molecular structure of ganciclovir from being destroyed, prolongs the shelf life of the product, ensures that it still maintains 100% bioactivity after reconstitution, and ensures the efficacy of clinical treatment while improving biological safety.

[0006] However, the freeze-drying process currently used in industrial production has a long cycle and extremely low production efficiency when used to prepare ganciclovir for injection, because ganciclovir is in a glassy state during freeze-drying, and the glass transition temperature is low, so collapse and melting easily occur during the first drying process. Therefore, the freeze-drying cycle is usually long, and the production efficiency is extremely low. The existing process easily causes collapse of the freeze-drying microstructure, the appearance of the obtained freeze-dried product shrinks, and the water treatment is not thorough enough, which affects the quality and stability of the drug. SUMMARY

[0007] In view of the prior art defects in the background art, the present application provides a 0.25g ganciclovir freeze-drying method. By controlling the phase gradient heating and vacuum degree control at 0mbar (vacuum without gas mixing, maintaining the limit vacuum) in the sublimation drying, reducing the influence of convective heat in the primary drying process, and controlling the low-oxygen environment cavity design concept, and adopting the gradient heating mode to set the optimal target temperature, the optimized freeze-drying sublimation drying path design is completed, so that the ganciclovir injection can realize efficient freeze-drying at a low collapse temperature on the basis of ensuring product quality. The average total freeze-drying time is less than 48h, the problems of low drying efficiency and easy collapse of finished products are solved, the freeze-dried preparation is completely reconstituted within 180s, the moisture control is less than 3.0%, and the appearance shows a complete white loose block.

[0008] In order to achieve the above-mentioned purpose, the present application adopts the following technical scheme: A 0.25g ganciclovir injection vacuum freeze-drying method, characterized in that it comprises the following steps: (1) Pre-freezing: the temperature of ganciclovir injection is reduced from room temperature to -45~-40℃ within 1min, and maintained for 2~3h; (2) Sublimation drying: The first stage temperature is increased to -15~-13℃ constant temperature within 60~90min, and maintained for 25~30h; the -15~-13℃ constant temperature refers to a certain constant temperature between -15 and -13℃; The second stage temperature is increased to -12℃ within 150~180min, and maintained for 2~3h; The third stage temperature is increased to -6~-4℃ within 100~120min; The fourth stage temperature is increased to 0℃ within 45~75min; (3) Desorption drying: The first stage temperature is increased to 8~12℃ within 50~80min; The second stage temperature is increased to 28~32℃ within 30~60min; The third stage temperature is increased to 55℃ within 40~50min, and maintained for 2~4h; (4) Plug: after freeze-drying, stop gas mixing, charge nitrogen, plug, and release vacuum.

[0009] In an alternative embodiment, the vacuum degree of the sublimation drying and the first stage of desorption drying is controlled at 0mbar, that is, vacuum without gas mixing, maintaining the limit vacuum; the sublimation drying adopts the gradient heating mode and sets the optimal target temperature.

[0010] In an alternative embodiment, the vacuum degree of the resolving drying second and third stages is 0.18-0.22 mbar.

[0011] In an alternative embodiment, the nitrogen gas is used for the aeration in the freeze-drying process, and the aeration is stopped after the temperature reaches 55℃ and is maintained for 2-4 h.

[0012] Compared with the prior art, the present application has the following beneficial effects: 1. The present application controls the vacuum degree by setting reasonable drying stages, thereby improving the drying efficiency to the maximum while ensuring the product quality, shortening the freeze-drying cycle by sufficient pre-freezing and segmented temperature rising, improving the production efficiency, and reducing the exposure time of the product under high-temperature vacuum, which is beneficial to reducing the generation of related substances.

[0013] 2. In the sublimation drying stage of the present application, the shelf temperature is increased and the freeze-drying pressure is adjusted after the product to be prepared is completely sublimated, thereby reducing the risk of product temperature exceeding the eutectic point due to early or rapid temperature rising, and the product obtained under the low collapse temperature is a loose block-shaped product with white color, complete skeleton, no delamination, collapse and shrinkage, full appearance, complete drying and low defect rate, which is significantly superior to the mesh-shaped, honeycomb-shaped or shrinkage deformation problems easily occurred in the traditional process. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Freeze-drying curve of ganciclovir for injection. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application will be further described in detail below with reference to the drawings in the embodiments of the present application. It should be noted that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0016] In order to make the purposes, technical solutions and advantages of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the drawings of the specification. In order to more clearly understand the above purposes, features and advantages of the present application, the advantages of the present application will be further described by comparing the embodiments with reference to the drawings and specific embodiments.

[0017] The formula and dosage of ganciclovir injection used in examples 1-3 and comparative examples 1-6 are shown in Table 1: Table 1 Formula amount of ganciclovir injection of 0.25 g specification

[0018] Preparation process: take 80% purified water, heated to 60℃, nitrogen, add 39.2g sodium hydroxide stirring to dissolve, add 250g of ganciclovir, stirring to dissolve, add purified water to 1500mL, pH value is 10.7~11.1, after filtering with 0.22μm polyether sulfone filter membrane, according to 1.5mL per bottle 10mL in a vial. Half of the filling, freeze-drying, freeze-drying method is described in the examples, with heat conducting oil as the heat transfer medium to control the shelf temperature, the prepared ganciclovir injection in turn through the pre-freezing, sublimation drying, analytical drying. Freeze-drying, nitrogen (-0.03~-0.01MPa), rolling cover, get 1000 bottles of ganciclovir injection freeze-dried preparation.

[0019] Example 1 This example presents a kind of 0.25g ganciclovir injection vacuum freeze-drying method, freeze-drying curve as shown in Figure 1 (1) pre-freezing: ganciclovir injection is in the condition of room temperature into box, set the shelf temperature to-40℃, 1min (within the performance of the equipment within the full power cooling) to-40℃ after the reduction, maintain 2h.

[0020] (2) sublimation drying: condenser to-50℃ or lower, start vacuum pump, vacuum to 0mbar (vacuum without gas, maintain the limit vacuum), start heating; set the shelf temperature to-14℃, 60min to-14℃ after the increase, maintain 25h, need 6 product temperature probe in not less than 5 probes shown temperature reaches shelf set temperature, then proceed to temperature rise, if not continue to sublimate; set the shelf temperature to-12℃, 180min to-12℃ after the increase, maintain 2h; set the shelf temperature to-5℃, 120min to-5℃ after the increase; set the shelf temperature to 0℃, 60min to 0℃.

[0021] (3) analytical drying: set the shelf temperature to 10℃, 60min to 10℃; set the shelf temperature to 30℃, 45min to 30℃; set the shelf temperature to 55℃, 30min to 55℃, maintain 3h.

[0022] Example 2 This example presents a kind of ganciclovir injection vacuum freeze-drying method: (1) pre-freezing: ganciclovir injection is in the condition of room temperature into box, set the shelf temperature to-40℃, 1min (within the performance of the equipment within the full power cooling) to-40℃ after the reduction, maintain 3h.

[0023] ​(2) Sublimation drying: The condenser is set to -50°C or below, the vacuum pump is turned on, and the vacuum is extracted to 0 mbar (vacuum extraction without air mixing, maintaining the limit vacuum). Heating is started. The shelf temperature is set to -15°C, and it is raised to -15°C in 90 min, and then maintained for 30 h. When the temperature of at least 5 probes of the 6 product temperature probes reaches the shelf set temperature, the temperature is raised. If it does not reach, sublimation is continued. The shelf temperature is set to -12°C, and it is raised to -12°C in 150 min, and then maintained for 2.5 h. The shelf temperature is set to -5°C, and it is raised to -5°C in 100 min. The shelf temperature is set to 0°C, and it is raised to 0°C in 45 min.

[0024] (3) Desorption drying: The shelf temperature is set to 12°C, and it is raised to 12°C in 75 min. The shelf temperature is set to 25°C, and it is raised to 25°C in 30 min. The shelf temperature is set to 55°C, and it is raised to 55°C in 50 min, and then maintained for 2 h.

[0025] Example 3 This example proposes a vacuum freeze-drying method for ganciclovir for injection: (1) Pre-freezing: The ganciclovir injection is put into the box at room temperature, the shelf temperature is set to -45°C, and it is reduced to -45°C in 1 min (representing full power cooling within the performance of the equipment), and then maintained for 2.5 h.

[0026] (2) Sublimation drying: The condenser is set to -50°C or below, the vacuum pump is turned on, and the vacuum is extracted to 0 mbar (vacuum extraction without air mixing, maintaining the limit vacuum). Heating is started. The shelf temperature is set to -13°C, and it is raised to -13°C in 75 min, and then maintained for 33 h. When the temperature of at least 5 probes of the 6 product temperature probes reaches the shelf set temperature, the temperature is raised. If it does not reach, sublimation is continued. The shelf temperature is set to -12°C, and it is raised to -12°C in 160 min, and then maintained for 2 h. The shelf temperature is set to -4°C, and it is raised to -4°C in 110 min. The shelf temperature is set to 0°C, and it is raised to 0°C in 75 min.

[0027] (3) Desorption drying: The shelf temperature is set to 8°C, and it is raised to 8°C in 55 min. The shelf temperature is set to 35°C, and it is raised to 35°C in 60 min. The shelf temperature is set to 55°C, and it is raised to 55°C in 40 min, and then maintained for 4 h.

[0028] Comparative Example 1 The vacuum degree is set to 0.2 mbar during the entire drying process (including sublimation drying and desorption drying), and the other steps are the same as in Example 1.

[0029] Comparative Example 2 During the pre-freezing stage, the shelf temperature was first set to -35°C, and after 60 minutes it dropped to -35°C, it was maintained for 3 hours; then the shelf temperature was set to 0°C, and after 30 minutes it rose to 0°C, it was maintained for 1 hour; finally, the shelf temperature was set to -40°C, and after 60 minutes it dropped to -40°C, it was maintained for 1.5 hours; other steps were the same as in Example 1.

[0030] Comparative Example 3 In the first stage of sublimation drying, the shelf temperature was set at -12°C, and after 60 minutes it was raised to -12°C, it was maintained for 25 hours. In the second stage, the shelf temperature was set at -10°C, and after 180 minutes it was raised to -10°C, it was maintained for 2 hours. Other steps were the same as in Example 1.

[0031] Comparative Example 4 The first stage of sublimation drying was set at -16°C. After reaching -16°C in 60 minutes, the temperature was maintained for 25 hours. Other steps were the same as in Example 1.

[0032] Comparative Example 5 After the first stage of sublimation drying reaches the set temperature of the shelf, it is maintained for 20 hours; other steps are the same as in Example 1.

[0033] Comparative Example 6 In the third stage of sublimation drying, the shelf temperature was set at -5°C, and after 120 minutes it was raised to -5°C and maintained for 1 hour. In the fourth stage, the shelf temperature was set at 0°C, and after 60 minutes it was raised to 0°C and maintained for 1 hour. In the first stage of analytical drying, the shelf temperature was set at 10°C, and after 30 minutes it was raised to 10°C and maintained for 1 hour. In the second stage, the shelf temperature was set at 30°C, and after 30 minutes it was raised to 30°C and maintained for 1 hour. Other steps were the same as in Example 1.

[0034] Comparative Example 7 This comparative example presents a vacuum freeze-drying method for 0.5g of ganciclovir for injection: The formulation and dosage of the ganciclovir injection used are shown in Table 2: Table 2. Formulation and dosage of 0.5g ganciclovir injection

[0035] Preparation process: Take 80% purified water, heat to 60℃, purge with nitrogen, add 78.4g of sodium hydroxide and stir to dissolve, add 500g of ganciclovir and stir to dissolve, add purified water to 300mL, adjust the pH to 10.7~11.1, filter through a 0.22μm polyethersulfone membrane, and dispense 3mL into 10mL vials. Half-stop, freeze-dry using the same method as in Example 1. After freeze-drying, purge with nitrogen (pressure -0.03~-0.01MPa), and cap to obtain 1000 vials of ganciclovir for injection.

[0036] The ganciclovir lyophilized formulations obtained in Examples 1-3 and Comparative Examples 1-7 were randomly sampled, and the properties of the finished products were observed. The defect rate of the finished products was calculated, and the clarity and color of the solution were observed. The results are shown in Table 3.

[0037] The formula for the finished product defect rate is as follows:

[0038] Table 3. Details of freeze-dried finished products

[0039] The results showed that, by controlling the vacuum level, setting the sublimation temperature to -13 to -15°C, and maintaining the temperature for 25 to 30 hours, the freeze-dried formulations obtained in Examples 1-3 exhibited better formability, with the lowest defect rate at 0.1% and the lowest moisture content at 1.26%. In contrast, the freeze-dried products obtained in Comparative Examples 1-6 had poorer formability, with the highest defect rate reaching 98% and the highest moisture content reaching 4.18% (exceeding the moisture limit of 3.0%). This indicates that higher vacuum levels or insufficient heat supply can lead to an increased product defect rate. Furthermore, adding pre-freezing annealing or holding the product at the shelf set temperature during the desorption drying stage not only fails to effectively improve the product properties but also prolongs the freeze-drying cycle and increases energy consumption. In Comparative Example 7, the ganciclovir was a 0.5% specification, resulting in a product with poor appearance and a defect rate of 32%, indicating that entering the desorption drying stage before complete sublimation leads to product melting.

[0040] The freeze-dried products obtained in Examples 1-3 and Comparative Examples 1-7 were randomly selected and subjected to high temperature (60°C) and light irradiation (4500±500 lx, near-ultraviolet energy 80 μW / cm²). 2 The product was placed under the following conditions for 10 days, then reconstituted with the lyophilized product that had not undergone any other treatment (0 days), and key formulation indicators were measured and the data were compared.

[0041] Take freeze-dried products that have been stored for 0 days, 10 days at high temperature, and 10 days under light, respectively. Use a sterile syringe to draw 5 mL of water for injection and slowly inject it into the freeze-dried powder injection vial along the vial wall. Gently rotate the vial or shake it slowly by hand to ensure that the water for injection and the freeze-dried powder are in full contact. Start timing after injection and start the shaking device (frequency set to 100 times / min) until the lumps are completely dissolved. Record the reconstitution time.

[0042] The solution after reconstitution of the freeze-dried products after 0 days, 10 days at high temperature, and 10 days under light was tested with a pH meter, and the pH value was recorded.

[0043] The solutions of the lyophilized products after 0 days, 10 days at high temperature, and 10 days under light were reconstituted and compared with Y-0.5 standard colorimetric solution (yellow series standard colorimetric solution, representing a very low intensity of yellow hue) and water for injection (blank control), respectively. If the solution color was no different from the blank control tube or the solution color was lighter than that of Y-0.5 standard colorimetric solution, it was judged as "solution color < Y-0.5". The results are shown in Table 4.

[0044] Table 4. Results of stability study of freeze-dried products

[0045] The results showed that the lyophilized formulations obtained in Examples 1-3 and Comparative Examples 1-7 were resistant to high temperature (60℃) and light irradiation (4500±500lx, 80μW / cm²). 2 After being placed under the specified conditions for 10 days, the sample properties, reconstitution time, alkalinity, color, and related substances did not change significantly, indicating that the finished product has good stability and strong resistance to environmental interference, and no additional optimization of the formulation or storage conditions is required for high temperature and light factors. However, by comparing the reconstitution time of the lyophilized formulations obtained in Examples 1-3 with those in Comparative Examples 1-7, it can be concluded that the reconstitution time of Comparative Examples 1-7 is relatively long, indicating that the lyophilized formulations obtained in the comparative examples have poor solubility.

[0046] In summary, the freeze-drying process provided by this invention, through staged temperature-controlled sublimation drying and temperature-controlled desorption drying under ultimate vacuum, ensures both product yield and freeze-drying efficiency. The prepared ganciclovir injectable freeze-dried formulation exhibits excellent appearance, low moisture content, rapid reconstitution, and good stability, with a clear and colorless solution after dissolution. Compared to the comparative example, it shortens the freeze-drying cycle while demonstrating superior overall performance.

[0047] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0048] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A vacuum freeze-drying method for 0.25g ganciclovir for injection, characterized in that, Includes the following steps: (1) Pre-freezing: The temperature of ganciclovir injection solution was lowered from room temperature to -45~-40℃ within 1 minute and maintained for 2~3 hours; (2) Sublimation drying: The first stage involves raising the temperature to a constant temperature of -15 to -13°C within 60 to 90 minutes and maintaining it for 25 to 30 hours; the constant temperature of -15 to -13°C refers to a constant temperature between -15 and -13°C. In the second stage, the temperature is raised to -12℃ in 150~180 minutes and maintained for 2~3 hours; The temperature in the third stage is increased to -6 to -4℃ in 100 to 120 minutes; In the fourth stage, the temperature is raised to 0℃ in 45-75 minutes; (3) Drying: The temperature in the first stage is increased to 8-12℃ in 50-80 minutes; The temperature in the second stage is increased to 28-32℃ in 30-60 minutes; In the third stage, the temperature is raised to 55℃ in 40-50 minutes and maintained for 2-4 hours. (4) Plugging: After the freeze-drying is completed, stop adding gas, fill with nitrogen, plug, and release the vacuum.

2. The vacuum freeze-drying method for 0.25g ganciclovir for injection according to claim 1, characterized in that, The vacuum level is controlled at 0 mbar throughout the sublimation drying process and the first stage of desorption drying, that is, vacuum is applied without gas mixing to maintain ultimate vacuum; the sublimation drying adopts a gradient heating method and sets the optimal target temperature.

3. The vacuum freeze-drying method for 0.25g ganciclovir for injection according to claim 1, characterized in that, The vacuum level in the second and third stages of the analytical drying process is 0.18~0.22 mbar.

4. The vacuum freeze-drying method for 0.25g ganciclovir for injection according to claim 1, characterized in that, The freeze-drying process uses nitrogen gas, and the gas mixing is stopped after the temperature reaches 55°C and is maintained for 2-4 hours.

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