Leltemovir composition and preparation method thereof

Abstract

The invention belongs to the field of medicine, and provides a letemovir composition and a preparation method thereof, the composition comprises letemovir, an alkaline reagent, a solubilizer, a buffer agent, a pH regulator, an excipient and water for injection; according to the composition, the solubility of letemovir is greatly improved, hydroxypropyl-beta-cyclodextrin is abandoned as a solubilizer in the prescription, so that the harm of kidney accumulation safety is avoided, and the composition does not contain other known organic solvents for injections, so that the medication safety is remarkably improved. The composition can be an injection or a freeze-dried powder injection, after the freeze-dried powder injection is redissolved or the injection is sterilized, the freeze-dried powder injection is clear liquid, no visible foreign matter exists, the compatibility stability is good, the adverse reaction risk caused by capillary obstruction is avoided or reduced, the safety and the clinical medication convenience are remarkably improved, the preparation process is simple and convenient, and the preparation cost is low. Large equipment is not needed, the equipment dependence degree is low, and large-scale production is facilitated.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of medicine, and particularly relates to a letermovir composition and a preparation method thereof. BACKGROUND

[0002] Letermovir is a high-activity drug for responding to HCMV infection, and its chemical name is (4S)-2-(8-fluoro-3-(2-methoxy-5-(trifluoromethyl)phenyl)-2-(4-(3-methoxyphenyl)piperazin-1-yl)-3,4-dihydroquinazolin-4-yl)acetic acid, its molecular formula is C 29 H 28 F4N4O4, and its molecular weight is 572.55, and its structural formula is as follows: .

[0003] Letermovir free base raw material medicine is an amorphous powder, and its pKa values are 3.6 and 7.1, mainly exists in the form of a zwitterion between pH 4 and pH 7, and has a low characteristic solubility of about 0.3 mg / mL. The solubility is increased to 7.7 mg / mL at pH 8 and 25.5 mg / mL at pH 9, respectively.

[0004] Letermovir is a new non-nucleoside anti-cytomegalovirus drug, which is developed by Aicuris Company in Germany for the first time. In October 2012, Merck paid 110 million euros of advance payment and 332.5 million euros of milestone fees to Aicuris to obtain the global rights of letermovir. Letermovir tablets and injections were approved for marketing in the United States for the first time in 2017, and the trade name is Prevymis ® , which becomes the first new anti-CMV drug approved for marketing by FDA in 15 years. In China, letermovir tablets were approved for marketing by NMPA in January 2022, and the trade name is Prevymis, which is used for preventing cytomegalovirus infection and cytomegalovirus disease in adult recipients of allogeneic hematopoietic stem cell transplantation who are cytomegalovirus seropositive. +

[0005] The original research product injection (trade name: Prevymis ® ​The prescription of Letemovir Injection (24 mL: 48 mg) contains a large amount of hydroxypropyl betadex (HP-β-CD) for solubilization, and each bottle of injection contains 3.6 grams of hydroxypropyl betadex (150 mg / mL). For patients with low kidney function, it is easy to cause accumulation of HP-β-CD. Cyclodextrin excipients can also cause damage to glomerular epithelial cells. The FDA instructions for Letemovir Injection clearly warn that HP-β-CD may cause ototoxicity. In addition, the original Letemovir Injection is a colorless and clear liquid and may contain translucent or white small particles related to the product, so additional post-processing is required before the intended use to remove the drug composition that has a tendency to cause particle problems due to dilution.

[0006] The Letemovir compound patent and formulation patent have expired in 2024, and domestic and foreign pharmaceutical companies or research institutions have carried out related research on Letemovir compounds and formulations. Patent document CN100393706C discloses a composition containing {8-fluoro-2-[4-(3-methoxyphenyl)piperazin-1-yl]-3-[2-methoxy-5-(trifluoromethyl)phenyl]-3,4-dihydroquinazolin-4-yl} acetic acid or its salt, solvate or solvate thereof, a promising candidate for introducing antiviral active substances, which can be used to combat infections caused by human cytomegalovirus. However, during the development process, it was found that the solubility of the substance was problematic, especially the complexity of the production process for stable formulations for intravenous administration or solid compositions for intravenous administration.

[0007] Patent document CN105555771A discloses a liquid pharmaceutical formulation containing amorphous Letemovir. However, the use of amorphous substances for the production of drugs is not ideal, as it is difficult to guarantee consistent purity in the case of amorphous substances, on the other hand, it is difficult to guarantee consistent pharmacological parameters, such as bioavailability, in the case of amorphous substances.

[0008] Patent documents CN115427112A and CN115581118A disclose a stable crystalline Letemovir salt, but the liquid composition prepared from the salt is not resistant to heat pressure sterilization, so the Letemovir salt disclosed in the patent can only be prepared into an oral preparation.

[0009] In summary, the related compositions in the prior art contain Letemovir and complexing solubilizers such as polyethylene glycol (PEG), cyclodextrin, etc., and in particular, the composition containing hydroxypropyl betadex (HP-β-CD) has a tendency to cause particle problems when dissolved in a parenterally acceptable diluent such as water for injection, and additional post-processing is required before the intended use, for example, filtering the drug composition before use. Therefore, developing a high-concentration Letemovir formulation that improves the solubility of Letemovir while ensuring safety has become a technical problem that needs to be solved in the field. Summary of the Invention

[0010] To overcome the shortcomings of existing technologies, this invention provides a high-concentration letermovir composition for intravenous infusion and its preparation method. The composition contains letermovir, an alkaline reagent, a solubilizer, a buffer, a pH adjuster, an excipient, and water for injection. This composition significantly improves the solubility of letermovir. The formulation eliminates hydroxypropyl betacyclodextrin as a solubilizer, thus avoiding the safety risks associated with renal accumulation. Furthermore, the composition does not contain other known organic solvents used in injections, significantly improving medication safety. This composition can be an injection solution or a lyophilized powder for injection. Both the reconstituted lyophilized powder for injection and the sterilized injection solution are clear solutions free of visible foreign matter, thereby avoiding or reducing the risk of adverse reactions due to capillary obstruction and significantly improving clinical medication safety.

[0011] The present invention provides a letermovir composition comprising a pH adjuster, an excipient, water for injection, and further comprising letermovir, an alkaline reagent, a solubilizer, and a buffer; the composition may be an injection solution or a lyophilized powder for injection.

[0012] The content of letermovir is 1-100 mg / mL, the molar ratio of letermovir to alkaline reagent is 1:(0.5-10), preferably 1:(0.9-5); the mass ratio of letermovir to solubilizer is 1:(0.1-10), preferably 1:(0.8-5.0); the mass ratio of letermovir to buffer is 1:(0.05-10), preferably 1:(0.5-1.0).

[0013] The alkaline reagent comprises one or more of an inorganic base, an inorganic salt, an organic base, and a basic amino acid. The inorganic base is selected from sodium hydroxide; the inorganic salt is selected from one or more of sodium carbonate, potassium carbonate, and disodium hydrogen phosphate; the organic base is selected from one or more of choline hydroxide, meglumine, ethylenediamine, triethanolamine, and tromethamine; and the basic amino acid is selected from one or more of arginine, lysine, and histidine. More preferably, one or more of sodium hydroxide, sodium carbonate, choline hydroxide, and meglumine are selected. Adding the alkaline reagent to the formulation significantly improves the solubility of the API in water.

[0014] The solubilizer is selected from one or more of polyethylene glycol 15-hydroxystearic acid, poloxamer 188, polyoxyethylene castor oil 35, polysorbate 80, and vitamin E polyethylene glycol succinate (TPGS1000). Preferably, it is selected from one or more of polyethylene glycol 15-hydroxystearic acid, poloxamer 188, and vitamin E polyethylene glycol succinate (TPGS1000). Adding a solubilizer to the formulation further improves the solubility of the API in water. This invention eliminates the use of cyclodextrin, employing a combination of solubilizer and alkaline reagent to significantly improve the solubility of the API in water (commercially available injections have a maximum solubility of only 20 mg / ml, while the injection solution of this invention has a maximum solubility of up to 100 mg / ml), and also increases the stability of the injection solution, thus increasing the safety for clinical use. If no solubilizer is added to the formulation, the injection solution has poor stability, is prone to precipitation, and the related substances results are significantly worse than those of samples with added solubilizers, resulting in a high risk of clinical use.

[0015] The buffer is selected from one or more of 4-hydroxyethylpiperazine ethanesulfonic acid (HEPES), phosphate buffered saline (PBS), and tris(hydroxymethyl)aminomethane (Tris). The phosphate buffer is composed of disodium hydrogen phosphate and sodium dihydrogen phosphate, with a molar ratio of disodium hydrogen phosphate to sodium dihydrogen phosphate of (1-35):1, preferably 20:1. The use of a buffer in the formulation significantly improves the compatibility and stability of the preparation.

[0016] The pH adjuster is selected from one or more of acidic pH adjusters or alkaline pH adjusters, wherein the acidic pH adjuster is selected from one or more of citric acid, acetic acid, hydrochloric acid, and phosphoric acid; and the alkaline pH adjuster is selected from one or more of sodium hydroxide and sodium carbonate.

[0017] When the prepared dosage form is a lyophilized powder injection, an appropriate amount of excipient needs to be added. The mass ratio of letermovir to excipient is 1:(1-50). The excipient includes one or more of mannitol, sucrose, trehalose, lactose, and dextran.

[0018] Furthermore, the present invention provides a method for preparing the aforementioned lemetmovir composition, wherein the dosage form is an injection solution or a lyophilized powder for injection, specifically including the following steps: (1) Weigh the prescribed amount of alkaline reagent, add 50-80% of the volume of the prepared drug solution of water for injection, stir to dissolve, and obtain an alkaline solution; weigh the prescribed amount of Letermovir, add it to the alkaline solution, heat in a water bath at 40-80℃ to obtain a solution, which is recorded as solution 1; (2) Weigh the amount of solubilizer prescribed and add it to solution 1. Heat in a water bath at 40-80℃ until completely dissolved to obtain a clear solution, which is recorded as solution 2. (3) Add the prescribed amount of buffer to solution 2, dissolve it, adjust the pH to 7.0-8.5 with pH adjuster, make up to volume or weight, filter it through a 0.22μm filter membrane to obtain the solution, which is called solution 3; (4) Divide the solution into ampoules or vials, seal or cap them, and autoclave at 121°C for 15 minutes to obtain Letermovir injection. (5) If preparing lyophilized powder for injection, the prescribed amount of excipients need to be added in step (2). After complete dissolution, proceed to step (3) to obtain a solution, which is denoted as solution 4. Dispense into vials, freeze dry, and obtain lyophilized powder for injection.

[0019] Furthermore, in step (1), the prescribed amount of Letermovir and alkaline reagent can be directly weighed and added directly to water for injection that accounts for 50-80% of the volume of the prepared drug solution. The solution is heated in a water bath at 40-80°C to obtain the solution, which is denoted as solution 1.

[0020] Furthermore, the specific steps of the freeze-drying operation in step (5) are as follows: 1) Pre-freezing: Place the partially stoppered sample into a freeze dryer, turn on the circulating pump and diaphragm cooling, set the diaphragm temperature to -30℃~-50℃ for 1 hour, and keep it warm for 2-4 hours; 2) First drying: After the main drying is set for 1 hour, the sample temperature reaches -25℃~15℃, and is kept at this temperature for 20-26 hours with a vacuum degree of 10-30Pa to perform the first drying of the sample; 3) Secondary drying: After setting the sample temperature to 20℃-30℃ for 1 hour, keep it at that temperature for 2-9 hours, and maintain a vacuum of 10-30 Pa to perform secondary drying on the sample.

[0021] The final lemetmovir composition obtained by this invention can be an injection solution or a lyophilized powder for injection, with a content of 1-100 mg / mL, preferably 10-100 mg / mL, a pH of 7.0-8.5, a particle size of 5-30 nm, and a transmittance >90%. When the composition is prepared as a lyophilized powder, it can be reconstituted with a compatible solution.

[0022] The obtained letermovir injection, as a novel non-nucleoside anti-cytomegalovirus drug, is indicated for adult recipients who are serologically positive for cytomegalovirus (CMV) and undergo allogeneic hematopoietic stem cell transplantation (HSCT). [R] + [Prevention of cytomegalovirus infection and cytomegalovirus disease. In specific applications, the reconstituted solution of the letermovir injection or lyophilized powder injection provided by this invention can be mixed with a compatibility solution and then administered by infusion. The compatibility solution is selected from one of sterile water for injection, 0.9% sodium chloride injection, 5% glucose injection, 5% glucose and 0.9% sodium chloride injection, and sodium lactate Ringer's injection. As a preferred embodiment, 5% glucose injection or 0.9% sodium chloride injection is preferred.]

[0023] Compared with the prior art, the present invention has achieved the following beneficial effects: (1) Greatly improves solubility This invention utilizes the salt formation of letermovir with an alkaline reagent to improve its solubility. Furthermore, the innovative addition of a solubilizer further enhances the solubility and stability of letermovir. The letermovir injection solution prepared by this invention achieves a concentration as high as 100 mg / mL, significantly improving drug solubility compared to commercially available injections (20 mg / mL).

[0024] (2) Significantly improves safety Original drug Prumin ® (Prevymis) ® This product contains hydroxypropyl betacyclodextrin, which may accumulate in patients with moderate to severe renal impairment (CrCl < 50 mL / min), raising safety concerns and limiting its clinical use. In particular, the need for CMV prophylaxis in high-risk populations (such as kidney transplant recipients) is significantly reduced or not covered.

[0025] Secondly, the recommended daily dose of hydroxypropyl betacyclodextrin in the original drug, Letermovir injection, is 3600 mg, exceeding the FDA's limit for inactive substances. This may increase the risk of local toxicity, allergies, hemolysis, and organ damage. According to the People's Republic of China's health industry standards for children under 7 years old, the P50 value for a 2-year-old child is 11.9 kg, and the ADI for HP-β-CD injection is 200 mg / kg / day. Therefore, the maximum acceptable daily exposure is 2.38 g. The recommended daily dose for children in the original Letermovir injection is 3.6 g, far exceeding this value. Therefore, a safer Letermovir injection solution needs to be developed to meet clinical needs, such as for pediatric use.

[0026] This invention eliminates the use of cyclodextrin and adopts innovative solubilization technology. The formulation consists of commonly used excipients that are easy to obtain, safe and stable. The amounts added are all within the FDA's range for the use of inactive substances. This significantly improves the safety of clinical medication while increasing solubility.

[0027] The injection prepared by this invention can be a sterile injection solution or a lyophilized powder injection. Both the reconstituted lyophilized powder injection and the sterile injection solution are clear solutions, free of visible foreign matter, contain qualified insoluble particles, and exhibit good stability. Compared to the original injection solution, Prevymis... ® The presence of visible transparent foreign particles avoids or reduces the risk of adverse reactions caused by capillary blockage, significantly improving the safety of the formulation.

[0028] (3) Improve adaptability The marketed original injectable solution is a colorless, clear liquid, but may contain translucent or white small particles. Therefore, additional post-processing is required before intended use to remove particles generated by dilution of the drug composition. For example, the drug composition may be filtered before use and administered through a sterile 0.2 μm or 0.22 μm polyethersulfone (PES) tandem filter.

[0029] This invention provides injectable solutions or lyophilized powder for injection, wherein the injectable solution can be selected from aqueous injections or infusions (corresponding concentrations of 1-2 mg / mL), satisfying multiple choices for clinical medication. The letermovir injection prepared by this invention can be directly diluted with compatible solutions such as 0.9% sodium chloride injection or 5% glucose injection to obtain a dosage concentration of 1-2 mg / mL. After reconstitution, the dosage control is more precise, and the reconstituted solution meets the standards for visible foreign matter and insoluble particles. The solution is clear and transparent, exhibiting good compatibility and greatly improving clinical compliance.

[0030] (4) Low cost and easy to scale up production The excipients in the formulation of this invention are simple, readily available, and inexpensive. The preparation process is simple, requiring only stirring, mixing, dissolving, and filtering. No special equipment is needed, and the process is easy to control. This effectively reduces the difficulty of preparing Letermovir injection and avoids the occurrence of bubbles, wall sticking, opalescence, and precipitation during the preparation process. The operation is simple and can be achieved with ordinary injection and powder injection production lines. It has high industrial feasibility, low production cost, and is easy to implement. Attached Figure Description

[0031] Figure 1 The image shows the morphological appearance of injectable termovir prepared by freeze-drying in Example 4; Figure 2 The image shows the appearance of the lemetmovir injection obtained in Example 1; Figure 3 The high-performance liquid chromatogram of related substances determination of lemetmovir injection obtained in Example 2 is shown. Figure 4 The particle size distribution of the solution prepared by the lyophilization method of Example 5, after being reconstituted with 5% glucose injection, is shown. Figure 5 The particle size distribution of the lemetmovir injection obtained in Example 1 during freeze-thaw cycles is shown. Detailed Implementation

[0032] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed in accordance with the techniques or conditions described in the literature in the field, or in accordance with the product manual.

[0033] Example 1: A letermovir injection solution, with the following formulation: The preparation method includes the following steps: (1) Weigh out the prescribed amount of letermovir and meglumine, add 90 mL of water for injection, and heat in a 50°C water bath until completely dissolved to obtain solution 1; (2) Weigh the prescribed amount of polysorbate 80 into solution 1, heat and stir in a water bath at 50°C until completely dissolved to obtain solution 2; (3) Add the prescribed amount of disodium hydrogen phosphate and sodium dihydrogen phosphate. After complete dissolution, adjust the pH value to 7.5 with 0.5 mol / L citric acid, bring the volume to 120 mL, filter with a 0.22 μm pore size filter membrane, and obtain solution 3; (4) Dispense the solution into 3 ampoules and autoclave at 121°C for 15 minutes to obtain Letemovir injection.

[0034] Figure 2 The image shows the appearance of the lemetmovir injection obtained in Example 1. The injection prepared in Example 1 is a colorless or almost colorless clear liquid with a content of 100.3%, a total impurity of related substances of 0.30%, and a pH of 7.5.

[0035] Example 2: A letermovir injection solution, with the following formulation: The preparation method includes the following steps: (1) Weigh out the prescribed amount of Letermovir and 4.4% choline hydroxide, add 80 mL of water for injection, and heat in a 50°C water bath until completely dissolved to obtain solution 1; (2) Weigh the prescribed amount of TPGS1000 into solution 1, heat and stir in a 50°C water bath until completely dissolved to obtain solution 2; The remaining steps are the same as in Example 1, which yields Lemetmovir injection.

[0036] The injection solution prepared in Example 2 is a colorless or almost colorless clear liquid with a content of 100.3%, a total impurity content of 0.32%, and a pH of 7.6.

[0037] Example 3: A lyophilized powder injection of letermovir, with the following formulation: The preparation method includes the following steps: (1) Weigh out the prescribed amount of sodium carbonate, add 40 mL of water for injection, dissolve completely, then add the prescribed amount of letermovir, heat in a 50°C water bath until completely dissolved, to obtain solution 1; (2) Weigh out the prescribed amount of polyoxyethylene castor oil 35 and trehalose and add them to solution 1. Heat in a water bath at 50°C and stir until completely dissolved to obtain solution 2. (3) Add tris(hydroxymethyl)aminomethane (Tris), and after complete dissolution, adjust the pH value to 8.0 with 0.5 mol / L citric acid or 1 mol / L sodium carbonate solution, bring the volume to 50 mL, filter with a 0.22 μm pore size filter membrane to obtain solution 4; (4) Dispense the solution into vials, each containing 240mg, and freeze-dry to obtain the freeze-dried powder injection.

[0038] The specific steps of the freeze-drying process are as follows: 1) Pre-freezing: Place the partially stoppered sample into a freeze dryer, turn on the circulating pump and diaphragm cooling, set the diaphragm temperature to -30℃~-50℃ for 1 hour, and keep it warm for 2-4 hours; 2) First drying: After the main drying is set for 1 hour, the sample temperature reaches -25℃~15℃, and is kept at this temperature for 20-26 hours with a vacuum degree of 10-30Pa to perform the first drying of the sample; 3) Secondary drying: After setting the sample temperature to 20℃-30℃ for 1 hour, keep it at that temperature for 2-9 hours, and maintain a vacuum of 10-30 Pa to perform secondary drying on the sample.

[0039] Example 3: The injectable temovir prepared by freeze-drying was a white solid or powder. After reconstitution with water for injection, it was a colorless or almost colorless clear liquid with a purity of 99.9%, a total impurity of related substances of 0.24%, a pH of 7.6, and a Z-Average of 8.254 nm.

[0040] Example 4: A lyophilized powder injection of letermovir, with the following formulation: The preparation method includes the following steps: (1) Weigh out the prescribed amount of letermovir and sodium carbonate, add 800 mL of water for injection, heat in a 50°C water bath until completely dissolved, and obtain solution 1; (2) Weigh the prescribed amount of sucrose and 15-hydroxystearic acid polyethylene glycol ester into solution 1, heat in a 50°C water bath, and stir until dissolved to obtain solution 2; (3) Add the prescribed amount of HEPES as a buffer system. After complete dissolution, adjust the pH value to 7.5 with 0.5 mol / L citric acid, bring the volume to 1200 mL, filter with a 0.22 μm pore size filter membrane, and obtain solution 4; (4) Dispense the solution into vials, each containing 240mg, and freeze-dry to obtain the freeze-dried powder injection.

[0041] The freeze-drying process used is the same as in Example 3.

[0042] like Figure 1 As shown, the lyophilized tetimovir injection prepared by the lyophilization method in Example 4 is a white block or powder. After reconstitution with water for injection, it is a colorless or almost colorless clear liquid with a content of 100.1%, a total impurity of related substances of 0.20%, a pH of 7.7, and a Z-Average of 8.760 nm.

[0043] Example 5: A lyophilized powder injection of letermovir, with the following formulation: The preparation method includes the following steps: (1) Weigh out the prescribed amount of sodium carbonate, add 800 mL of water for injection, heat in a 60°C water bath to dissolve, add the prescribed amount of letermovir, and continue stirring until dissolved to obtain solution 1; (2) Weigh out the prescribed amount of 15-hydroxystearic acid polyethylene glycol ester and sucrose, add them to solution 1, heat in a 60°C water bath, stir and dissolve to obtain solution 2; (3) Add the prescribed amount of HEPES, dissolve completely, and adjust the pH to 8.0 with 1 mol / L sodium carbonate solution to obtain solution 4; The subsequent steps are the same as those in Example 4.

[0044] The lyophilized temovir injection obtained in Example 5 was a white lumpy or powdery substance. After reconstitution with water for injection, it became a colorless or nearly colorless clear liquid with a pH of 7.8 and a Z-Average of 6.135 nm.

[0045] Figure 4 The particle size distribution of the solution prepared by the freeze-drying method of Example 5, after being reconstituted with 5% glucose injection, is shown.

[0046] Example 6 A lemetmovir composition, the formulation of which is shown in Table 1 below.

[0047] Table 1 Summary of Prescriptions Observed Prepare 100 mL of each of compositions 1-8 according to the following steps: (1) Weigh the prescribed amount of sodium carbonate and place it in a clean container. Dissolve it in approximately 80% of the target drug volume of water for injection. Add an appropriate amount of letermovir to dissolve it so that the final API concentration in the system is 24 mg / mL. This solution is called solution 1. (2) Add solubilizers such as polyethylene glycol 15-hydroxystearic acid, poloxamer 188, and polyethylene glycol succinate of vitamin E to solution 1 to achieve a final concentration of 24 mg / mL, and record it as solution 2. (3) Add the corresponding buffer in the prescription to solution 2 and adjust the final pH of the solution to the range of 7.0-8.5. Add the composition to the target volume using water for injection and filter it through a 0.22μm filter membrane to obtain solution 3. (4) Divide the solution into ampoules or vials, seal or cap them, and autoclave at 121°C for 15 minutes to obtain Letermovir injection.

[0048] The effect of adding a buffer to the formulation on compatibility stability was investigated, and the experimental results are as follows: (1) Compositions 1-8 were sterilized at 121°C for 15 minutes and all yielded clear solutions. No precipitates were observed after sterilization, and no condensation or layering was observed in the compositions with added solubilizers.

[0049] (2) When a buffer is added to compositions 4-8, surprisingly, the pH value after sterilization is the same as before sterilization. Other compositions (compositions 1-3) without added buffers show a pH value change of more than 1 unit after sterilization, such as from 6.5 to 5.3.

[0050] (3) No crystals were observed in the compositions 1-8 after freeze-thaw cycle test and low temperature cycle test, and no significant changes were observed in solution color, pH value, clarity, content and related substances.

[0051] (4) Compositions 1-8 were respectively mixed with 5% glucose injection to the clinically used concentration, and the pH value of the mixed solutions was in the range of 7.5-8.0. After standing at room temperature (25°C) for 4 hours, precipitates were observed in the mixed solutions of compositions 1-3. Surprisingly, no precipitates were observed in the mixed solutions of compositions 4-8 within 12 hours; and no precipitates or significant turbidity were observed in the mixed solutions within 24 hours. Therefore, it is necessary to add buffers such as HEPES to the prescription. The addition can significantly improve the compatibility stability of the injection and ensure that the mixed solutions are stable and do not precipitate after standing at room temperature (25°C) for 24 hours.

[0052] Comparative Example 1: Letermovir injection was prepared according to the published patent CN104144678A, and its raw material formula is as follows: Letemovir 4.8g Sodium hydroxide 288 mg Hydroxypropyl b cyclodextrin 36g Sodium chloride 744 mg Q.S. with Water for Injection 240 mL The preparation method includes the following steps: (1) Weigh out the prescribed amounts of termovir, sodium chloride and sodium hydroxide, add an appropriate amount of water, and heat in a 50°C water bath; (2) Add hydroxypropyl betacyclodextrin and sodium chloride to the solution obtained in (1) one after another. After dissolving, adjust the pH value to 7.5 with 1 mol / L hydrochloric acid. (3) The solution obtained in (2) was brought to a final volume of 240 mL and filtered through a 0.22 μm pore size filter membrane; (4) Dispense the solution obtained in (3) into vials and sterilize at 121°C for 15 min to obtain Lemetmovir injection.

[0053] Experimental Example 1: Determination of Content and Related Substances The determination of content and related substances shall be carried out according to the following methods.

[0054] 1. Content determination method Chromatographic conditions: Octadecylsilane-bonded silica gel was used as the stationary phase (Agilent Eclipse XDB-C18 250mm×4.6mm, 5μm is recommended); 10mM phosphate buffer (1.36g potassium dihydrogen phosphate, 1000mL water, shaken well; pH adjusted to 2.5 with phosphoric acid) was used as mobile phase A, and water-acetonitrile (10:90) was used as mobile phase B; the detection wavelength was 234nm; the injection volume was 10μl.

[0055] Reference solution: Take about 25 mg of the reference standard and place it in a 25 mL volumetric flask. Dilute to the mark with solvent and shake well. Accurately measure 1 mL and place it in a 20 mL volumetric flask. Dilute to the mark with solvent and shake well.

[0056] Test solution: Accurately measure 5 mL of this product into a 100 mL volumetric flask, dilute to the mark with solvent, and shake well. Accurately measure 1 mL into a 10 mL volumetric flask, dilute to the mark with solvent, and shake well.

[0057] Solvent: 10% acetonitrile.

[0058] 2. Related Substances Testing Methods Chromatographic conditions: Octadecylsilane-bonded silica gel (Sunniest C18, specification: 250×4.6mm, 5μm) was used as the stationary phase; 10mM phosphate buffer (1.36g potassium dihydrogen phosphate, 1000mL water, shaken well; pH adjusted to 2.5 with phosphoric acid) was used as mobile phase A, and water-acetonitrile (10:90) was used as mobile phase B; the detection wavelength was 234nm; and the injection volume was 20μl.

[0059] Table 2 Gradient elution table for related substances test method of Letermovir injection Test solution: Accurately measure 1 mL of this product and place it in a 20 mL volumetric flask. Dilute to the mark with solvent and shake well.

[0060] The contents and related substances of Examples 1-5, Compositions 1-6, and Comparative Example 1 were tested according to the above-mentioned content and related substance detection methods, and the results are shown in Table 3. The prepared lemetmovir composition (after reconstitution of lyophilized powder) was tested for visible foreign matter and insoluble particles according to the Chinese Pharmacopoeia, and the results are shown in Table 4 below. The related substance results after sterilization in Example 2 are shown in the figure below.Figure 3 As shown.

[0061] Figure 3 The high-performance liquid chromatogram of related substances determination of lemetmovir injection obtained in Example 2 is shown, indicating that the method has good separation.

[0062] Table 3. Detection results of content, related substances, etc. in Examples 1-5, Compositions 1-6, and Comparative Example 1. Table 4 Results of Detection of Visible Foreign Matter in Insoluble Particulate Matter The injections of Examples 1-5 and Compositions 1-6 showed no visible foreign matter after sterilization and lyophilization and reconstitution, and the insoluble microparticles met the standards of the 2025 edition of the Chinese Pharmacopoeia. The content and related substances were all within the standards, and the quality of the injections was good. The related substances in the injection prepared in Comparative Example 1 were significantly higher than those in the Example, and there were clearly visible particles under the clarity tester. The insoluble particulate matter exceeded the standard, posing a great risk.

[0063] Experimental Example 2 Compatibility Stability The injection solutions prepared in Examples 1-5, Compositions 4-8, and Comparative Example 1 were subjected to high-temperature testing (60℃ / 30 days), including freeze-thaw cycles (3 rounds) and low-temperature cycles (3 rounds). After final sampling (the lyophilized powder was first reconstituted), the solutions were diluted with 250 ml of 0.9% sodium chloride injection and 5% glucose injection, respectively, and placed at room temperature (25℃) for 24 h to assess their stability under clinical use conditions. The dilution stability was investigated using the content and related substance analysis methods described in Example 1, and the results are shown in Tables 5-7.

[0064] After sampling the prepared injection solution or lyophilized powder injection at the end of the stability period, the samples were mixed and placed at room temperature (25℃) for 24 hours. The properties and pH were then tested. The results are summarized in Table 5.

[0065] Table 5. Compatibility results of the final stability test sample with 0.9% sodium chloride injection. Note: ① "-" indicates "no crystals precipitated", "+" indicates "crystals precipitated", "++" indicates "severe crystal precipitation", and "+++" indicates "turbidity"; ②The compatibility reagent is 5% glucose injection. Take 24 mL of the preparation and put it into 250 mL of the compatibility solution. After standing at room temperature for 24 h, test the properties and pH. ③ " / " indicates "not performed".

[0066] Table 6. Content determination results of the compatibility solution in Example 1 Table 7. Results of related substance determination of the compatibility solution in Example 1 Note: The samples used in Tables 6 and 7 are those after three rounds of freeze-thaw cycle tests.

[0067] As shown in Table 5, the injection solutions prepared in Examples 1-5 were placed at room temperature (25°C) for 24 hours after the completion of three rounds of low temperature cycling and freeze-thaw cycling tests on day 0 and after being placed at a high temperature of 60°C for 30 days. No crystals were precipitated in either case. The pH value of the mixed solutions was in the range of 7.5-8.0.

[0068] As shown in Tables 6-7, after three freeze-thaw cycles, the sample from Example 1 was mixed with 5% glucose injection and 0.9% sodium chloride injection, respectively. The mixed solutions were placed at room temperature (25°C) for 24 hours. Compared with 0 hours, the content and related substances did not change significantly, indicating that the prepared lemetmovir injection has good compatibility stability.

[0069] Figure 4 The particle size distribution diagram of the solution prepared by the freeze-drying method of Example 5, lyophilized lemetmovir powder for injection, after being mixed with 5% glucose injection is shown. There was no significant change in particle size before and after mixing.

[0070] Experiment Example 3: Influencing Factors Experiment The letermovir compositions prepared in Examples 4-5, Compositions 4-6 and Comparative Example 1 were subjected to a high-temperature test at 60°C. Samples were taken at 10 and 30 days respectively. The content of letermovir compositions and related substances were determined according to Experimental Example 1. The results are shown in Table 8.

[0071] Table 8 Results of the Experiment on Influencing Factors After being placed at a high temperature of 60°C for 30 days, compared with day 0, there were no significant differences in the properties, clarity and color, pH value, content and related substances of Examples 4-5, Compositions 4-6 and Comparative Example 1 after reconstitution; compared with Comparative Example 1, there were no significant differences in Examples 7-8 and Compositions 4-6, indicating that the lemetmovir injection prepared by adding solubilizers in this invention is of the same quality as the lemetmovir injection prepared by the original research using hydroxypropyl betacyclodextrin.

[0072] Compared to hydroxypropyl betacyclodextrin, the amount of solubilizers such as 15-hydroxystearic acid polyethylene glycol added to the formulation is significantly reduced, and the solubility of lemetmovir is significantly improved. Moreover, the quality properties of the prepared lemetmovir injection are consistent. The injection prepared by this invention has significant advantages over the original drug.

[0073] Experiment Example 4: Low Temperature Cycling Test The lemetmovir composition prepared in Example 1 was subjected to a low-temperature cycling test. The test should include 3 cycles. Each cycle was placed at 2-8°C for 2 days and then at 40°C for 2 days. Samples were taken and tested after each cycle. The results are shown in Table 9.

[0074] Table 9 Results of the low-temperature cycling test in Example 1 As shown in Table 9, no precipitation occurred after the three cycles. Compared with day 0, there were no significant changes in pH, clarity, color, particle size, content, and related substances, indicating that the prepared Letermovir injection can withstand the low-temperature cycling test and has good low-temperature tolerance.

[0075] Experimental Example 5: Freeze-thaw Test The lemetmovir composition prepared in Example 1 was subjected to a freeze-thaw cycle test. The test should include 3 cycles. Each cycle was placed at -20 to -18°C for 2 days and then at 40°C for 2 days. This was repeated for 3 rounds. Samples were taken and tested after each round. The results are shown in Table 10.

[0076] Table 10 Freeze-thaw test results of Example 1 As shown in Table 10, no precipitation occurred after three rounds of freeze-thaw cycles. Compared with day 0, there were no significant changes in pH, clarity, color, particle size, content, and related substances. The particle size distribution of the lemetmovir injection obtained in Example 1 after three rounds of freeze-thaw cycles is shown in the figure below. Figure 5 As shown, the above results indicate that the Bentemovir composition can withstand freeze-thaw tests.

[0077] Experimental Example 6: Accelerated and Long-Term Tests The letermovir injection solutions in Examples 4-5 and Compositions 4-6 were subjected to stability studies under the following conditions. Changes in appearance, properties, pH value and particle size were recorded. The letermovir content and related substances were determined according to Experimental Example 1 above. The results are shown in Table 11.

[0078] Long-term test: 25℃±2℃ / 60%RH±5%RH; Accelerated test: 40℃±2℃ / 75%RH±5%RH.

[0079] Table 11. Results of stability studies in accelerated and long-term tests. Conclusion: As shown in the table above, the letermovir compositions of Examples 4-5 and Compositions 4-6, after being stored under long-term stability and accelerated stability conditions for 6 months, showed no significant changes in appearance, pH, particle size, content, or related substances. These results indicate that the letermovir injection prepared according to this invention exhibits good stability. The storage conditions for letermovir injection are tentatively set at room temperature, and based on the accelerated stability test results, the shelf life is tentatively set at 2 years.

[0080] For those skilled in the art, the specific embodiments are merely illustrative descriptions of the present invention. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A letimovir composition comprising a pH adjusting agent, an excipient, and water for injection; characterized in that, The composition further comprises letimovir, an alkaline agent, a solubilizer, a buffer; wherein the content of letimovir is 1-100 mg / mL, the molar ratio of letimovir to alkaline agent is 1:0.5-10, the mass ratio of letimovir to solubilizer is 1:0.1-10, and the mass ratio of letimovir to buffer is 1:0.05-10.

2. The letimovir composition according to claim 1, characterized in that, The molar ratio of the letimovir to the alkaline agent is 1:0.9-5; the mass ratio of the letimovir to the solubilizer is 1:0.8-5.0; and the mass ratio of the letimovir to the buffer is 1:0.5-1.

0.

3. The letimovir composition according to claim 1, characterized in that, The alkaline agent comprises one or more of inorganic bases, inorganic salts, organic bases, and basic amino acids; wherein the inorganic base is selected from sodium hydroxide, the inorganic salt is selected from one or more of sodium carbonate, potassium carbonate, and disodium hydrogen phosphate, the organic base is selected from one or more of choline hydroxide, meglumine, ethylenediamine, triethanolamine, and tromethamine, and the basic amino acid is selected from one or more of arginine, lysine, and histidine; The solubilizer is selected from one or more of 15-hydroxystearic acid polyethylene glycol ester, poloxamer 188, polyoxyethylene castor oil 35, polysorbate 80, and vitamin E polyethylene glycol succinate; The buffer is selected from one or more of 4-hydroxyethylpiperazine ethanesulfonic acid, phosphate buffer, and tris-hydroxymethyl aminomethane, wherein the phosphate buffer is composed of disodium hydrogen phosphate and sodium dihydrogen phosphate, and the molar ratio of disodium hydrogen phosphate to sodium dihydrogen phosphate is 1-35:1; The pH regulator is selected from one or more of an acidic pH regulator or an alkaline pH regulator, wherein the acidic pH regulator is selected from one or more of citric acid, acetic acid, hydrochloric acid, and phosphoric acid, and the alkaline pH regulator is selected from one or more of sodium hydroxide and sodium carbonate.

4. The letimovir composition according to claim 3, characterized in that, The alkaline agent is one or more of sodium hydroxide, sodium carbonate, choline hydroxide, and meglumine; The solubilizer is one or more of 15-hydroxystearic acid polyethylene glycol ester, poloxamer 188, and vitamin E polyethylene glycol succinate; The molar ratio of disodium hydrogen phosphate to sodium dihydrogen phosphate in the phosphate buffer is 20:

1.

5. The telomexo composition according to any one of claims 1 to 4, characterized in that, The content of the letimovir composition is 10-100 mg / mL, the pH is 7.0-8.5, the particle size is 5-30 nm, and the light transmittance is >90%.

6. The letimovir composition according to claim 5, characterized in that, The composition is an injection solution or a lyophilized powder, wherein when the composition is a lyophilized powder, the lyophilized powder is reconstituted with a compatible solution selected from one of sterile water for injection, 0.9% sodium chloride injection, 5% glucose injection, 5% glucose and 0.9% sodium chloride injection, and sodium lactate Ringer's injection.

7. The letimovir composition according to claim 6, characterized in that, When the composition is a lyophilized powder, an excipient is added, wherein the mass ratio of letimovir to the excipient is 1:1-50, and the excipient is one or more of mannitol, sucrose, trehalose, lactose, and dextran.

8. A process for the preparation of a letimovir composition, characterized in that, Specifically comprising the following steps: (1) Weigh the prescribed amount of alkaline agent, add 50-80% of the volume of water for injection based on the prepared solution, stir and dissolve to obtain an alkaline solution; weigh the prescribed amount of letimovir and add it to the alkaline solution, heat in a water bath at 40-80°C to obtain a solution, which is recorded as solution 1; (2) Take the prescribed amount of solubilizer to solution 1, heated in water bath at 40-80℃, to obtain a clear solution, recorded as solution 2; (3) Add the prescribed amount of buffer to solution 2, after dissolution, adjust the pH to 7.0-8.5 with pH adjuster, constant volume or constant weight, filter with 0.22μm filter membrane to obtain a solution, recorded as solution 3; (4) Divide solution 3 into ampoules or vials, seal or plug and cap, heat sterilization at 121℃ for 15min, to obtain letmovir injection; (5) When preparing lyophilized powder injection, add the prescribed amount of excipient to solution 1 in step (2), after complete dissolution, proceed with step (3) to obtain solution, recorded as solution 4, divide into vials, lyophilize to obtain letmovir lyophilized powder injection.

9. The method of preparing a letimovir composition according to claim 8, characterized in that, In step (1), take the prescribed amount of letmovir and alkaline reagent, add 50-80% of the volume of water for injection, heated in water bath at 40-80℃ to obtain a solution, recorded as solution 1.

10. The method of claim 8, wherein the letimovir composition is prepared by, The specific steps of lyophilization in step (5) are as follows: 1) Pre-freezing: Put the half-plugged sample into the freeze-drying machine, start the circulating pump baffle refrigeration, set the baffle temperature to reach -30℃ to -50℃ for 1h, and keep the temperature for 2-4h; 2) First drying: After setting for 1h, the sample temperature reaches -25℃ to 15℃, keep the temperature for 20-26h, vacuum degree is 10-30Pa, and the sample is dried for the first time; 3) Second drying: After setting for 1h, the sample temperature reaches 20℃ to 30℃, keep the temperature for 2-9h, vacuum degree is 10-30Pa, and the sample is dried for the second time.

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