Hematopoietic stem cell activator injection containing plerixafor and preparation method thereof

Abstract

The invention discloses a hematopoietic stem cell activator injection containing plerixafor and a preparation method thereof, and belongs to the technical field of medicines. Aiming at the problems of low dissolution efficiency, insufficient stability, risk of organic solvent residue and the like in the development of a plerixafor preparation, the preparation method comprises the following steps: dissolving plerixafor in a hydrochloric acid-organic solvent system to realize synergistic pre-dissolution, adding citric acid to form a stable compound, and carrying out reduced pressure rotary evaporation to remove the organic solvent. According to the injection and the preparation method thereof, the dissolution time and the process time are remarkably shortened, the stability of the preparation can be effectively enhanced, the clinical adverse reaction risk is reduced, and the injection is suitable for clinical application related to hematopoietic stem cell transplantation.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to an injection solution containing plexafor as a hematopoietic stem cell activator and its preparation method. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Prexavir is a hematopoietic stem (progenitor) cell activator that stimulates the proliferation, differentiation, and entry into the bloodstream of hematopoietic stem (progenitor) cells. Multiple studies have demonstrated that, under the combined action of granulocyte-stimulating factor (G-CSF) or granulocyte-monocyte-stimulating factor (GM-CSF), Prexavir can increase the proliferation of hematopoietic stem (progenitor) cells, significantly increasing the number released into the peripheral blood, and increasing the peripheral blood CD34+ cell population and hematopoietic progenitor cell colonies, thus significantly increasing the success rate of autologous hematopoietic stem cell transplantation.

[0004] Since most remission and progression cases of non-Hodgkin lymphoma (NHL) and multiple myeloma (MM) require peripheral blood autologous hematopoietic stem cell transplantation, and Mozobil combined with G-CSF can significantly increase the number of CD34+ cells in the peripheral blood of patients, increasing the number of CD34+ cells in the peripheral blood of approximately 60% of patients, thus ensuring the success of autologous hematopoietic stem cell transplantation in NHL and MM patients, it has good market development prospects.

[0005] Prexafolate is a polycyclic molecule containing nitrogen atoms. It is slightly soluble in aqueous solution with a pH greater than 11. Researchers have found that although the free base form of prexafolate is poorly soluble, its solubility increases significantly when it combines with an acid to form a bound salt. Therefore, to develop injectable formulations of prexafolate and increase the solubility of its active group, current research focuses on increasing drug solubility and improving its stability in aqueous solution. The traditional process involves directly adding prexafolate to water and then adjusting with acid to form a salt, thereby increasing its solubility and stability in water. However, in practice, this process is prone to drug clumping, leading to excessively long dissolution times, incomplete dissolution, and the precipitation of microcrystals. This results in substandard clarity and insoluble particles, increasing oxidative degradation impurities and posing a significant clinical risk.

[0006] Chinese patents with publication numbers CN104069061A and CN110123742A have achieved some success in improving the solubility of plexafor through the application of hydrochloric acid. However, the stability of the prepared plexafor aqueous solution still has room for improvement, and there is a possibility of oxidative degradation during storage, which may potentially affect the safety of clinical use to some extent. Chinese patent CN108403627A uses acetic acid as a co-solvent for plexafor and adds propylene glycol to adjust the polarity of the solvent to improve the solubility of plexafor and solve the problem of easy crystallization of plexafor injection. However, the addition of organic solvents increases the risk of adverse clinical reactions. Summary of the Invention

[0007] Prexavir, a key drug in hematopoietic stem cell transplantation, has long had its clinical value validated, but its formulation development has been hampered by two major challenges. First, low dissolution efficiency. Prexavir's free base is only slightly soluble in water. Traditional processes use a "direct addition of water + acid adjustment" method to promote dissolution, but this easily leads to clumping due to excessively high local concentrations—drug particles agglomerate, resulting in dissolution times exceeding 8 hours. Furthermore, the precipitation of tiny crystals during storage can cause deficiencies in clarity and insoluble microparticles, increasing oxidative degradation impurities and posing safety risks for clinical use. Second, insufficient stability. To improve solubility, existing technologies attempt to form salts with hydrochloric acid or introduce acetic acid and propylene glycol. However, the former's aqueous solution is prone to oxidative degradation during storage, with the content of related substances increasing significantly over time; while the latter reduces crystallization, residual organic solvents increase the risk of adverse reactions such as allergies, limiting its clinical application. The core issue is that the polycyclic nitrogen-containing structure of plexafor is sensitive to the environment, and simple "forced dissolution" or "single solubilization" cannot balance dissolution efficiency and long-term stability, which has become a problem restricting its formulation upgrade.

[0008] The breakthrough of this invention stems from a deep analysis of the molecular properties of plexafor: its nitrogen-containing groups readily form salts with acids, but the binding force with different acids, the water solubility of the complex, and the antioxidant capacity vary significantly; simultaneously, the polarity of the organic solvent can regulate the molecular dispersion state, affecting subsequent dissolution efficiency. Based on this, the inventors have constructed a three-step strategy of "pre-dissolution-complexation-purification":

[0009] (1) Hydrochloric acid-organic solvent synergistic pre-dissolution: Presalifos is first dissolved in a hydrochloric acid-organic solvent (such as ethanol) system. Hydrochloric acid opens the hydrogen bonds between presalifos molecules through protonation, while organic solvents lower the molecular aggregation energy barrier by adjusting polarity. The two work together to rapidly disperse the drug, avoiding clumping at the source, and shortening the dissolution time from 8 hours to 10 minutes.

[0010] (2) Precise citric acid complex: Citric acid is added to the pre-dissolved system, and its three carboxyl groups form a stable "multi-point binding" complex with the nitrogen-containing groups of plexafor. This structure not only has better water solubility than salts formed by phosphoric acid, malic acid, etc., but also inhibits the oxidative degradation pathway through steric hindrance, which becomes the core of the stability improvement.

[0011] (3) Low-temperature rotary evaporation purification: The organic solvent is removed by rotary evaporation under reduced pressure at 35-55℃, which avoids the damage of the complex by high temperature and eliminates the risk of organic solvent residue (the injection solution of this invention has no organic residue).

[0012] Compared with the prior art, the technical advantages of the present invention are as follows:

[0013] (1) Through the “pre-dissolution-compound” mechanism, the dissolution time of Plexafor is greatly shortened and no complex stirring equipment is required, which greatly reduces the production cost.

[0014] (2) The present invention achieves a qualitative leap in stability: After 6 months of accelerated testing (40℃ / 75%RH), the total impurity content of related substances in Example 1 is low, far lower than that of the prior art; after 12 months of long-term testing (30℃ / 65%RH), the solution remains clear, with no visible foreign matter, and the pH fluctuation is ≤0.2, which fully verifies the structural stability of the citric acid complex.

[0015] (3) Comprehensive optimization of safety: The organic solvent residue in the process of this invention is completely removed, and the insoluble particles and visible foreign matter strictly comply with the pharmacopoeia standards, which reduces the risk of adverse clinical reactions from the formulation level. Detailed Implementation

[0016] To make the objectives and technical solutions of this invention clearer, the following embodiments are provided for further explanation. However, the scope of protection of this invention is not limited to these embodiments; the embodiments are merely for illustrative purposes. Those skilled in the art should understand that any changes or equivalent substitutions that do not depart from the concept of this invention are included within the scope of protection of this invention.

[0017] Example 1: Hematopoietic stem cell activator injection containing plexafor

[0018] Components:

[0019] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 Osmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0020] Example 2: Hematopoietic stem cell activator injection containing plexafor

[0021] Components:

[0022] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.0 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200 ml, fill, sterilize, and the solution is obtained.

[0023] Example 3: Hematopoietic stem cell activator injection containing plexafor

[0024] Components:

[0025] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.7 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0026] Example 4: Hematopoietic stem cell activator injection containing plexafor

[0027] Components:

[0028] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.9 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 Osmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0029] Example 5: Hematopoietic stem cell activator injection containing plexafor

[0030] Components:

[0031] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 5.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 Osmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0032] Comparative Example 1 was carried out according to the scheme of Example 1 of Patent CN 104069061 A (converted to 24mg of praxavir).

[0033] Comparative Example 2 was carried out according to the scheme of Example 1 of Patent CN 108403627 A (converted to 24mg of praxavir).

[0034] Comparative Example 3: Hematopoietic stem cell activator injection containing plexafor

[0035] Components:

[0036] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, phosphoric acid was added, dissolved, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor phosphate complex; (2) Preparation of injection solution: Dissolve plexaphos phosphate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0037] Comparative Example 4: Hematopoietic stem cell activator injection containing plexafor

[0038] Components:

[0039] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, malic acid was added and dissolved, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor malic acid complex. (2) Preparation of injection solution: Dissolve malic acid plexafor complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 Osmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0040] Comparative Example 5: Hematopoietic stem cell activator injection containing plexafor

[0041] Components:

[0042] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, tartaric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor tartrate complex. (2) Preparation of injection solution: Dissolve tartaric acid praxaf complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 Osmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0043] Comparative Example 6: Hematopoietic stem cell activator injection containing plexafor

[0044] Components:

[0045] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0046] Comparative Example 7: Hematopoietic stem cell activator injection containing plexafor

[0047] Components:

[0048] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0049] Comparative Example 8: Hematopoietic stem cell activator injection containing plexafor

[0050] Components:

[0051] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0052] Comparative Example 9: Hematopoietic stem cell activator injection containing plexafor

[0053] Components:

[0054] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor complex; (2) Preparation of injection solution: Dissolve the plexafor complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200 ml, fill, sterilize, and the solution is obtained.

[0055] Comparative Example 10: Hematopoietic stem cell activator injection containing plexafor

[0056] Components:

[0057] Preparation method: (1) Preparation of plexafor citrate: plexafor is dissolved in an organic solvent solution, citric acid is added, the solution is dissolved, and the organic solvent is removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0058] Comparative Example 11: Hematopoietic stem cell activator injection containing plexafor

[0059] Components:

[0060] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in a citric acid-organic solvent solution, hydrochloric acid was added, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0061] Comparative Example 12: Hematopoietic stem cell activator injection containing plexafor

[0062] Components:

[0063] Preparation method: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent-citric acid solution, and the organic solvent was removed by rotary evaporation under reduced pressure at 35℃-55℃ to obtain plexafor citrate complex. (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 6.5 with pH adjuster, stir and clarify, add osmotic pressure adjuster to adjust to 270-310 mOsmol / kg, add water for injection to 1200ml, fill, sterilize, and the solution is obtained.

[0064] Comparison of process times in Examples 1-5 and Comparative Examples 1-12

[0065] Table 1. Process duration and dissolution time for Examples 1-3 and Comparative Examples 1-12

[0066] Note: [1] refers to the preparation time of Plexafor citrate; [2] refers to the dissolution time of the Plexafor citrate complex.

[0067] The process time is mainly related to the dissolution efficiency of plexafor, including the type of acid, the type of organic solvent, and the order of preparation steps. Table 1 shows that in Comparative Examples 3-5, phosphoric acid, malic acid, and tartaric acid were used to replace citric acid. Although these acids could form salts with plexafor, the binding force between these acids and plexafor and the water solubility of the complex were weaker than those of the citric acid complex, resulting in a longer dissolution time, but shorter than the traditional process. Comparative Examples 6-8 replaced organic ethanol, leading to a decrease in dissolution or rotary evaporation efficiency and a longer process time, but still better than the system without a suitable solvent. In Comparative Example 9, plexafor only formed hydrochloride salts, with weak synergistic solubilization and a tendency to agglomerate; the dissolution time was close to that of the traditional process. In Comparative Example 10, the free base of plexafor had extremely low solubility in organic solvents, reacted slowly with citric acid, had poor dissolution efficiency, and a long time. Comparative Examples 11-12 changed the order of addition of hydrochloric acid and citric acid, affecting the synchronicity of complex formation and decreasing dissolution efficiency, but still better than the unoptimized system.

[0068] Stability of Plexafor injection

[0069] Accelerated testing

[0070] Examples 1-5 and Comparative Examples 1-12 were subjected to accelerated release at 40℃±2℃ and RH75%±5% for 6 months. The pH, insoluble particles, clarity, visible foreign matter, content, related substances, and osmotic pressure of the plexafor injection were then measured.

[0071] Table 2. Test results before the experiment (day 0) Serial Number pH value Insoluble particles Clarity Visible foreign objects content(%) Maximum single impurity (%) of relevant substances Total impurities (%) osmotic pressure mOsmol / kg Example 1 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.12 0.006 0.008 278 Example 2 6.0 Compliant Lighter than 0.5 turbidity solution Compliant 100.2 0.006 0.008 283 Example 3 6.7 Compliant Lighter than 0.5 turbidity solution Compliant 99.8 0.007 0.010 280 Example 4 6.9 Compliant Lighter than 0.5 turbidity solution Compliant 99.9 0.007 0.011 288 Example 5 5.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.0 0.009 0.013 287 Comparative Example 1 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.7 0.016 0.029 279 Comparative Example 2 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.1 0.018 0.032 275 Comparative Example 3 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.9 0.013 0.026 280 Comparative Example 4 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.0 0.017 0.028 282 Comparative Example 5 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.8 0.012 0.025 286 Comparative Example 6 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.9 0.014 0.024 279 Comparative Example 7 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.1 0.015 0.027 281 Comparative Example 8 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.8 0.017 0.028 280 Comparative Example 9 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.7 0.013 0.026 285 Comparative Example 10 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.3 0.015 0.024 284 Comparative Example 11 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 99.9 0.012 0.023 282 Comparative Example 12 6.5 Compliant Lighter than 0.5 turbidity solution Compliant 100.2 0.014 0.025 278

[0072] Table 3. Accelerated test results after 6 months Serial Number pH value Insoluble particles Clarity Visible foreign objects content(%) Maximum single impurity (%) of relevant substances Total impurities (%) osmotic pressure mOsmol / kg Example 1 6.6 Compliant Lighter than 0.5 turbidity solution Compliant 99.8 0.010 0.016 278 Example 2 6.1 Compliant Lighter than 0.5 turbidity solution Compliant 99.9 0.012 0.017 283 Example 3 6.6 Compliant Lighter than 0.5 turbidity solution Compliant 99.7 0.011 0.016 281 Example 4 6.8 Compliant Lighter than 0.5 turbidity solution Compliant 99.6 0.013 0.018 288 Example 5 5.6 Compliant Lighter than 0.5 turbidity solution Compliant 99.9 0.014 0.020 286 Comparative Example 1 6.0 Compliant Lighter than turbidity solution No. 1 A small amount of visible foreign matter 98.0 0.035 0.060 276 Comparative Example 2 5.8 Compliant Lighter than turbidity solution No. 1 A small amount of visible foreign matter 97.5 0.042 0.070 273 Comparative Example 3 6.2 Compliant Lighter than 0.5 turbidity solution Compliant 98.2 0.022 0.052 279 Comparative Example 4 6.1 Compliant Lighter than 0.5 turbidity solution Compliant 98.0 0.021 0.045 281 Comparative Example 5 6.2 Compliant Lighter than 0.5 turbidity solution Compliant 98.3 0.023 0.044 285 Comparative Example 6 6.4 Compliant Lighter than 0.5 turbidity solution Compliant 98.5 0.024 0.055 278 Comparative Example 7 6.3 Compliant Lighter than 0.5 turbidity solution Compliant 98.2 0.028 0.050 280 Comparative Example 8 6.1 Compliant Lighter than 0.5 turbidity solution Compliant 98.0 0.026 0.042 279 Comparative Example 9 5.9 Compliant Lighter than 0.5 turbidity solution A small amount of visible foreign matter 97.8 0.025 0.052 284 Comparative Example 10 6.0 Compliant Lighter than 0.5 turbidity solution A small amount of visible foreign matter 98.0 0.022 0.048 283 Comparative Example 11 6.2 Compliant Lighter than 0.5 turbidity solution Compliant 98.2 0.026 0.047 281 Comparative Example 12 6.3 Compliant Lighter than 0.5 turbidity solution Compliant 98.3 0.029 0.055 277

[0073] Accelerated testing is a key method for rapidly assessing the stability of formulations under stringent conditions. Table 3 shows that the plexafor injection solutions in Examples 1-5 exhibit excellent stability, with minimal pH fluctuations, and all insoluble particles, clarity, and visible foreign matter meet the requirements. The content retention rate is ≥99.6%, and the increase in related substances is slow. In contrast, the stability of the comparative examples is significantly worse. The existing technical solutions (Comparative Examples 1-2) show a significant decrease in pH, reduced clarity, and visible foreign matter, with total related substances reaching 0.60%-0.70%. Although other comparative examples (such as replacing acids, organic solvents, or changing the process sequence) are superior to the existing technology, the total related substances and content retention rate are still lower than those of the examples, confirming the key role of citric acid, ethanol, and specific process sequences in improving the stability of the formulation.

[0074] Long-term trial

[0075] Examples 1-5 and Comparative Examples 1-12 were subjected to long-term exposure at 30℃±2℃ and RH 65%±5% for 12 months. The pH, insoluble particles, clarity, visible foreign matter, content, related substances, and osmotic pressure of the plexafor injection were measured.

[0076] Table 4. Results of the 12-month long-term test Serial Number pH value Insoluble particles Clarity Visible foreign objects content(%) Maximum single impurity (%) of relevant substances Total impurities (%) osmotic pressure mOsmol / kg Example 1 6.4 Compliant Lighter than 0.5 turbidity solution Compliant 99.8 0.007 0.009 278 Example 2 6.0 Compliant Lighter than 0.5 turbidity solution Compliant 99.7 0.007 0.010 284 Example 3 6.7 Compliant Lighter than 0.5 turbidity solution Compliant 99.6 0.008 0.010 282 Example 4 6.6 Compliant Lighter than 0.5 turbidity solution Compliant 99.5 0.008 0.014 288 Example 5 5.7 Compliant Lighter than 0.5 turbidity solution Compliant 99.7 0.009 0.015 285 Comparative Example 1 6.1 Compliant Lighter than turbidity solution No. 1 A small amount of visible foreign matter 98.5 0.028 0.067 277 Comparative Example 2 6.0 Compliant Lighter than turbidity solution No. 1 A small amount of visible foreign matter 98.0 0.031 0.062 274 Comparative Example 3 6.3 Compliant Lighter than turbidity solution No. 1 Compliant 98.3 0.025 0.055 279 Comparative Example 4 6.2 Compliant Lighter than turbidity solution No. 1 Compliant 98.2 0.026 0.053 281 Comparative Example 5 6.3 Compliant Lighter than turbidity solution No. 1 Compliant 98.4 0.025 0.058 285 Comparative Example 6 6.4 Compliant Lighter than 0.5 turbidity solution Compliant 98.8 0.027 0.046 278 Comparative Example 7 6.1 Compliant Lighter than 0.5 turbidity solution Compliant 98.6 0.028 0.049 280 Comparative Example 8 6.2 Compliant Lighter than 0.5 turbidity solution Compliant 98.5 0.025 0.052 279 Comparative Example 9 6.0 Compliant Lighter than turbidity solution No. 1 A small amount of visible foreign matter 98.0 0.022 0.054 283 Comparative Example 10 6.1 Compliant Lighter than turbidity solution No. 1 A small amount of visible foreign matter 98.2 0.026 0.061 282 Comparative Example 11 6.3 Compliant Lighter than turbidity solution No. 1 Compliant 98.3 0.022 0.059 280 Comparative Example 12 6.2 Compliant Lighter than turbidity solution No. 1 Compliant 98.4 0.027 0.057 276

[0077] The results in Table 4 show a trend consistent with the accelerated test. Examples 1-5 maintain good stability, with qualified pH and physical indicators, content retention rate ≥99.5%, and total impurities of related substances ≤0.015%. Existing technical solutions (Comparative Examples 1-2) and comparative examples without citric acid or with changed process sequence still show decreased clarity, visible foreign matter, and higher content of related substances than the examples. This further confirms that the present invention can ensure the long-term stability of Plexafor injection.

Claims

1. A hematopoietic stem cell activator injection containing plexafor, characterized in that, The injection solution comprises the following components by weight: 15-35 parts of pleroxafer, 30-80 parts of hydrochloric acid, 10-800 parts of organic solvent, 15-65 parts of citric acid, appropriate amount of osmotic pressure regulator, appropriate amount of pH regulator, and appropriate amount of water for injection.

2. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The hydrochloric acid is 2-10 mol / L hydrochloric acid.

3. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The organic solvent is selected from at least one of ethanol, isopropanol, and methanol.

4. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The organic solvent is ethanol.

5. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The osmotic pressure regulator is selected from at least one of sodium chloride, glucose, and mannitol.

6. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The osmotic pressure regulator is sodium chloride.

7. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The pH adjuster is selected from at least one of citric acid, phosphate, sodium hydroxide, and hydrochloric acid.

8. The hematopoietic stem cell activator injection solution containing plexafor according to claim 1, characterized in that, The pH adjuster is citric acid.

9. A method for preparing the hematopoietic stem cell activator injection solution containing plexafor as described in claim 1, characterized in that, The preparation method includes the following steps: (1) Preparation of plexafor citrate: plexafor was dissolved in hydrochloric acid-organic solvent solution, citric acid was added, dissolved, and the organic solvent was removed by rotary evaporation under reduced pressure to obtain plexafor citrate complex; (2) Preparation of injection solution: Dissolve plexafor citrate complex in an appropriate amount of water for injection, adjust the pH of the solution to 5.5-6.9 with pH adjuster, stir and clarify, add osmotic pressure adjuster, add water for injection to the total amount, fill, sterilize, and the solution is obtained.

10. The preparation method according to claim 9, characterized in that, The temperature of the reduced pressure rotary evaporation is 35℃-55℃.

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