A precisely-proportioned carboxymethyl chitosan and glycerophosphate sodium joint cavity filling preparation, a preparation method and application thereof

Abstract

The application discloses a joint cavity filling preparation of precisely proportioned carboxymethyl chitosan and sodium glycerophosphate and a preparation method and application thereof, and the effective component of the filling preparation is carboxymethyl chitosan with a concentration of 25 mg / mL and sodium glycerophosphate with a concentration of 15 mg / mL, and the balance is a sterile isotonic physiological buffer aqueous solution. The application forms component synergy by relying on the lubrication and long-acting stability characteristics of carboxymethyl chitosan and combining the structure reinforcement, ion regulation and cartilage repair promoting characteristics of sodium glycerophosphate, and effectively solves the defects of short in-vivo retention time, poor mechanical stability, lack of biological repair activity and easy dilution and collapse of the traditional joint filling material in the joint cavity fluid. The application overcomes the problem that a high-concentration viscous solution cannot be filtered and sterilized, can effectively buffer the joint mechanical load, optimize the joint microenvironment and promote the repair of degenerative cartilage, is suitable for clinical scenes such as mild and moderate osteoarthritis, sports joint injury and postoperative joint function repair, and has good clinical application value and industrialization prospect.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a precisely proportioned joint cavity filling formulation of carboxymethyl chitosan and sodium glycerophosphate, its preparation method, and its application. Background Technology

[0002] Osteoarthritis, articular cartilage wear, and sports-related joint injuries are common degenerative and traumatic orthopedic diseases. Their core pathological features include synovial fluid loss, increased joint space, degeneration and wear of the cartilage surface, and imbalance of joint mechanical stress, leading to clinical symptoms such as joint pain, stiffness, and limited range of motion. A common minimally invasive intervention for these conditions is the injection of a lubricating agent into the joint cavity. This fills the joint space, reduces the coefficient of friction, and provides rapid relief of clinical symptoms.

[0003] Currently, most mainstream joint filler materials used in clinical practice are single hyaluronic acid or single chitosan derivative formulations, which generally have significant technical shortcomings: single polysaccharide matrix materials are easily diluted and structurally disintegrate in the dynamic fluid circulation environment of the joint cavity, resulting in a short effective retention period in vivo and requiring repeated injections, increasing the burden of diagnosis and treatment for patients; at the same time, traditional materials only have physical filling and lubrication functions and lack the biological activity to actively repair damaged cartilage or regulate the pathological microenvironment of the joint, thus failing to block the progression of degenerative joint diseases; in addition, some composite filler formulations require the addition of chemical cross-linking agents to improve structural strength, posing a risk of additive residues and requiring improvement in biosafety. Furthermore, in terms of aseptic achievement, aseptic products are commonly sterilized by filtration or moist heat sterilization. During filtration sterilization, single biological agents exhibit high viscosity at high concentrations, making filtration impossible, and therefore these are all low-concentration formulations. Moist heat sterilization generally requires cross-linking agents or alcohols such as sorbitol to improve high-temperature resistance. The introduction of cross-linking agents or alcohols carries the risk of additive residues, and biosafety needs to be improved. In addition, moist heat sterilization can destroy the micro-network structure of biological agents, thereby affecting product performance. Summary of the Invention

[0004] This invention addresses the shortcomings of existing technologies by providing a precisely proportioned joint filling formulation of carboxymethyl chitosan and sodium glycerophosphate, its preparation method, and its application. This invention is achieved through the following technical solution: This invention discloses a precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint filling biological agent, composed of functional components and a sterile physiological buffer aqueous solution. The functional components are carboxymethyl chitosan and sodium glycerophosphate. Based on the total volume of the biological agent, the concentration of carboxymethyl chitosan is 25 mg / mL, and the concentration of sodium glycerophosphate is 15 mg / mL. The biological agent is a homogeneous colloidal system formed by physical compounding at room temperature. No exogenous chemical crosslinking agents, preservatives, or artificial synthetic thickeners are added to the system. The biological agent is suitable for joint cavity filling, joint lubrication, and repair of degenerated cartilage.

[0005] As a further improvement, the carboxymethyl chitosan of the present invention has a degree of deacetylation ≤50%, can be completely dissolved in a sterile aqueous solvent at room temperature, and the system is free of agglomerated particles and insoluble impurities.

[0006] As a further improvement, the sodium glycerophosphate of the present invention is composed of one or a combination of α-sodium glycerophosphate, β-sodium glycerophosphate.

[0007] As a further improvement, the biological agent described in this invention is tested at 25°C for 0.25 seconds. -1 The dynamic viscosity at the point is ≥2000 mPa·s; the biological agent is prepared by filtration and sterilization.

[0008] This invention also discloses a method for preparing a joint cavity filling biological agent with a precise ratio of carboxymethyl chitosan and sodium glycerophosphate, comprising the following steps: S1. Select medical-grade carboxymethyl chitosan with a degree of deacetylation ≤50%, slowly add it to sterile isotonic physiological buffer water, stir at low speed for 20-30 minutes to completely dissolve the powder, and prepare a uniform and transparent carboxymethyl chitosan aqueous solution with a concentration of 25 mg / mL. The system is free of agglomerated particles and precipitated impurities. S2. Accurately weigh medical-grade sodium β-glycerophosphate and add it to the above carboxymethyl chitosan base solution. Stir continuously for 15-20 minutes until completely mixed. Adjust the volume to stabilize the sodium glycerophosphate concentration in the system at 15 mg / mL to obtain a homogeneous composite solution. S3. After heating the above composite solution to 50-70℃, filter the composite solution with a 0.22μm sterile filter membrane to remove bacteria, let it stand for 5-10 minutes to remove air bubbles, and finally obtain a clear, uniform, and highly fluid joint cavity filling composite preparation, which is then aseptically sealed and stored for later use.

[0009] This invention also discloses the application of a precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint cavity filling biological agent in the preparation of minimally invasive injectable drugs for the treatment of osteoarthritis, sports joint injuries, and postoperative joint function repair.

[0010] This invention discloses a precisely proportioned joint cavity filling formulation and its preparation method, belonging to the field of biomedical materials technology. The effective components of the filling formulation are carboxymethyl chitosan at a concentration of 25 mg / mL and sodium glycerophosphate at a concentration of 15 mg / mL, with the remainder being a sterile isotonic physiological buffer solution. This invention leverages the lubricating and long-lasting stabilizing properties of carboxymethyl chitosan, combined with the structural reinforcement, ion regulation, and cartilage repair-promoting properties of sodium glycerophosphate, to form a synergistic effect. This effectively solves the defects of traditional joint filling materials, such as short in vivo retention time, poor mechanical stability, lack of biorepair activity, and susceptibility to dilution and disintegration by joint fluid. This invention overcomes the problem of high-concentration viscous solutions being unable to be filtered for sterilization, effectively buffering joint mechanical loads, optimizing the joint microenvironment, and promoting the repair of degenerated cartilage. It is suitable for clinical scenarios such as mild to moderate osteoarthritis, sports-related joint injuries, and postoperative joint functional repair, possessing good clinical application value and industrialization prospects.

[0011] Carboxymethyl chitosan, a modified polysaccharide derivative of natural chitin, possesses excellent water solubility, biocompatibility, viscoelasticity, and tissue adhesion, making it an ideal matrix material for soft tissue lubrication and repair. However, pure carboxymethyl chitosan aqueous solutions have low mechanical strength and weak resistance to dilution, and are prone to decomposition at room temperature in solution form, making it difficult to meet the clinical requirements for long-term joint cavity filling. Sodium glycerophosphate can participate in the metabolism of human cartilage matrix and the regulation of local joint ion balance, and can generate weak intermolecular interactions with polysaccharide molecular chains, optimizing the colloidal network structure, enhancing the mechanical strength of carboxymethyl chitosan aqueous solutions, and simultaneously improving temperature resistance to slow down the decomposition rate, thus meeting the clinical requirements for long-term joint cavity filling. A search revealed no publicly reported technical solutions for applying a high-concentration, high-viscosity system with a precise ratio of 25 mg / mL carboxymethyl chitosan + 15 mg / mL sodium glycerophosphate, using filtration to obtain a sterile product for joint cavity filling. This invention, through a unique precise ratio design, achieves simultaneous optimization of the material's physical properties and bioactivity, effectively filling the gap in existing technologies.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Unique and Exclusive Formulation: This invention is the first to propose a composition of 25 mg / mL carboxymethyl chitosan and 15 mg / mL sodium glycerophosphate, along with an optimal and precise ratio. The parameters are unique and the performance is stable, filling the gap in existing technologies for the single composition ratio of carboxymethyl chitosan and sodium glycerophosphate. Furthermore, this invention is the first to apply this specific binary composite system to minimally invasive joint filling and repair through filtration sterilization, representing a completely new technical application solution with strong patent protection and exclusivity.

[0013] 2. This patent employs a process combining heating at 50-70℃ with filtration through a 0.22μm sterile membrane to sterilize the composite solution. This process ensures that the high-concentration carboxymethyl chitosan retains its intact molecular structure after sterilization. Leveraging its excellent viscoelasticity, a colloidal substrate adapted to the physiological environment of the joint is constructed, achieving both clinical application and joint treatment benefits. In clinical applications, this colloidal substrate provides the good fluidity required for minimally invasive injections while also stably adhering to the surface of articular cartilage to form a uniform protective film. In treatment, it effectively buffers joint friction, reduces synovial inflammatory edema and exudation, improves chronic joint inflammation, and simultaneously lowers the joint friction coefficient, breaking the vicious cycle of continuous cartilage wear.

[0014] The optimal concentration for this system is 15 mg / mL sodium glycerophosphate. This component can form weak bonds with carboxymethyl chitosan molecular chains to construct a dense colloidal network structure, fundamentally solving the pain points of existing technologies: on the one hand, it significantly improves the temperature resistance of the material, overcoming the technical difficulties of high-concentration viscous preparations being unable to be sterilized by heating and filtration and difficult to retain the complete molecular structure, thus realizing the technical implementation of aseptic preparation of high-concentration preparations; on the other hand, it greatly improves the material's ability to resist antibody dilution and mechanical disintegration, effectively extending the effective retention period of the material in vivo, and solving the industry shortcomings of traditional materials such as low viscoelasticity, fast degradation rate, and the need for multiple injections.

[0015] Meanwhile, the optimal ratio of sodium glycerophosphate can precisely replenish phosphate ions in the joint area, precisely regulate chondrocyte proliferation and matrix secretion behavior, create an excellent microenvironment for chondrocyte adhesion, proliferation and matrix synthesis and secretion, effectively promote the repair and remodeling of superficial joint cartilage, and upgrade traditional joint treatment from simple physical symptomatic treatment to a new technical mode of highly efficient biological causal repair.

[0016] The precise ratio of carboxymethyl chitosan and sodium glycerophosphate creates a highly efficient synergistic effect, which not only effectively avoids the performance defects of single materials, but also avoids problems such as ion accumulation and excessive system density. Ultimately, it achieves multiple core technological advantages such as minimally invasive injection of the formulation, stable and long-lasting in vivo structure, efficient joint lubrication, and active cartilage repair.

[0017] 3. Integrated functions and treatment of both the cause and the cause: This invention integrates multiple functions such as physical filling and lubrication, long-term stabilization, and microenvironment regulation, breaking through the limitations of traditional materials that only have a single physical relief effect. It can effectively delay or even reverse early joint degenerative lesions, and achieve a combination of symptomatic relief and causal repair.

[0018] 4. No exogenous additives, achieving a dual upgrade in safety and performance: Existing high-performance composite filler materials mostly rely on chemical cross-linking agents to improve structural strength, posing biosafety risks. This invention achieves structural reinforcement solely through the weak intermolecular interactions generated by the precise ratio of the two components. High viscosity of the formulation is maintained through heating and filtration sterilization, without the need for any exogenous toxic additives. This simplifies the preparation process, reduces production costs, and significantly improves the medical safety and retention of the formulation, achieving an overall innovative upgrade of the technical solution. Attached Figure Description

[0019] Figure 1 These are SEM images of the microstructure; the left image shows the structure before and after the pushing. Figure 2 This is an AM (Ambulatory Acid) diagram of cells; the left side represents the blank control, and the right side represents the biological agent. Figure 3 These are pathological sections of the joint cavity; the left side is the blank control, and the right side is the biological agent. Detailed Implementation

[0020] This invention discloses a precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint filling biological agent, composed of functional components and a sterile physiological buffer aqueous solution. The functional components are carboxymethyl chitosan and sodium glycerophosphate. Based on the total volume of the biological agent, the concentration of carboxymethyl chitosan is 25 mg / mL, and the concentration of sodium glycerophosphate is 15 mg / mL. The biological agent is a homogeneous colloidal system formed by physical compounding at room temperature. No exogenous chemical crosslinking agents, preservatives, or synthetic thickeners are added to the system. The biological agent is suitable for joint space filling, joint lubrication, and repair of degenerated cartilage. The degree of deacetylation of carboxymethyl chitosan is ≤50%, and it is completely soluble in a sterile aqueous solvent at room temperature. The system is free of agglomerated particles and insoluble impurities. The sodium glycerophosphate is composed of one or a combination of α-sodium glycerophosphate and β-sodium glycerophosphate. The biological agent is tested at 25°C for 0.25 s. -1 The dynamic viscosity at the point is ≥2000 mPa·s; the biological agent is prepared by filtration and sterilization.

[0021] This invention also discloses a method for preparing a joint cavity filling biological agent with a precise ratio of carboxymethyl chitosan and sodium glycerophosphate, comprising the following steps: S1. Select medical-grade carboxymethyl chitosan with a degree of deacetylation ≤50%, slowly add it to sterile isotonic physiological buffer water, stir at low speed for 20-30 minutes to completely dissolve the powder, and prepare a uniform and transparent carboxymethyl chitosan aqueous solution with a concentration of 25 mg / mL. The system is free of agglomerated particles and precipitated impurities. S2. Accurately weigh medical-grade sodium β-glycerophosphate and add it to the above carboxymethyl chitosan base solution. Stir continuously for 15-20 minutes until completely mixed. Adjust the volume to stabilize the sodium glycerophosphate concentration in the system at 15 mg / mL to obtain a homogeneous composite solution. S3. After heating the above composite solution to 50-70℃, filter the composite solution with a 0.22μm sterile filter membrane to remove bacteria, let it stand for 5-10 minutes to remove air bubbles, and finally obtain a clear, uniform, and highly fluid joint cavity filling composite preparation, which is then aseptically sealed and stored for later use.

[0022] This invention also discloses the application of a precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint cavity filling biological agent in the preparation of minimally invasive injectable drugs for the treatment of osteoarthritis, sports joint injuries, and postoperative joint function repair.

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments: Example 1: Preparation of a precisely proportioned joint filling formulation In a sterile, clean environment at room temperature, using sterile isotonic phosphate buffered water as a solvent, medical-grade carboxymethyl chitosan with a degree of deacetylation of 38% was added and stirred until completely dissolved. The solution was then brought to a final volume to prepare a homogeneous carboxymethyl chitosan solution with a concentration of 25 mg / mL. Medical-grade sodium β-glycerophosphate was then precisely added and stirred continuously until completely dissolved. The concentration of sodium β-glycerophosphate in the system was adjusted to 15 mg / mL. After heating the solution to 70°C and maintaining the temperature for 20 minutes, the composite system was filtered through a 0.22 μm sterile filter membrane to remove bacteria. The system was then allowed to stand to remove air bubbles, ultimately yielding a clear, homogeneous, and minimally invasive injectable joint cavity filling composite preparation.

[0024] The joint cavity filling formulation prepared using the method of Example 1 was tested for rheological properties at 25°C and 2.5 Hz. The measured viscous modulus was 20.8 Pa and the elastic modulus was 4.95 Pa. Performance testing verified that the formulation of this example has excellent flowability and can pass smoothly through a 27G minimally invasive injection needle, meeting the requirements for minimally invasive clinical drug delivery.

[0025] The joint cavity filling formulation prepared using the method of Example 1 was tested at 25°C for 0.25 seconds. -1 The dynamic viscosity was tested and found to be 3172 mPa·s. The dynamic viscosity of the formulation in this embodiment is similar to that of normal joint synovial fluid (1-175 Pa·s), which meets the requirements for clinical efficacy.

[0026] The joint cavity filling formulation prepared using the method of Example 1 was observed under a scanning electron microscope to examine its microstructure before and after compression. It was found that both formulations exhibited a spatial network structure, with no significant difference in the network structure before and after compression. (See [link to example 1]). Figure 1It has good colloidal structure stability.

[0027] Biosafety assessment of intra-articular filling formulations The joint cavity filling formulation prepared using the method in Example 1 was used to add the stock solution of gel material / blank control to well plates inoculated with cells. After culturing for 24 hours, AM live / dead staining was used to characterize whether the formulation stimulated live cells. The experimental results are as follows: Figure 2 As shown, the cell compatibility test results showed that the cell viability was ≥98% and there was no cytotoxicity.

[0028] The joint cavity filling formulation prepared using the method of Example 1 was subjected to an intradermal induction phase, a local induction phase, and a challenge phase to observe whether it induced skin sensitization. In the intradermal induction phase, appropriate amounts of the sample concentrate and corresponding control solutions were injected intradermally into animals. In the local induction phase, appropriate amounts of the sample concentrate and corresponding control solutions were applied to animals. In the challenge phase, appropriate amounts of the sample concentrate and corresponding control solutions were applied to animals. The applications were removed after 24 hours, and the condition of each application site was observed and recorded at 24 hours and 48 hours after removal. Erythema and edema reactions at each application site were described and graded according to the Magnusson and Kligman grading system for each observation period, and the test results were recorded as shown in Table 1 below. The intradermal sensitization test showed that the sample did not induce skin sensitization.

[0029] Table 1. Test Results

[0030] The joint cavity filling formulation prepared using the method in Example 1 was administered intradermally to animals, with both the stock solution and the control solution being injected separately. The condition of each injection site was observed and recorded at 24h, 48h, and 72h post-injection. The tissue reaction scores for erythema and edema at each injection site were determined using the skin reaction scoring system provided by the system, and the results are recorded in Table 2 below. Under the experimental conditions, the results showed no intradermal reaction in the test sample.

[0031] Table 2 Experimental Results

[0032] Animal efficacy evaluation of intra-articular filling formulations The joint cavity filling formulation prepared using the method in Example 1 was injected into the joint cavity of rabbits after establishing an osteoarthritis (OA) model. Histopathological images of the blank model group and the experimental group were compared after 6 weeks, as shown below. Figure 3As shown, animal efficacy test results indicate that there was no redness or swelling at the injection site, no obvious inflammatory reaction, and the effective retention period in the body can reach more than 6 weeks. It can significantly improve joint lubrication and is more effective than commercially available products. It can effectively promote cartilage repair in osteoarthritis.

[0033] Comparative Example 1: Joint filling formulations with different component ratios Joint filling formulations with different carboxymethyl chitosan / sodium glycerophosphate ratios were prepared, and the remaining preparation process was the same as in Example 1. The performance was tested as shown in Table 3 below: Table 3. Dynamic viscosity and permeability of sterile filtration membranes with different component ratios

[0034] As can be seen from Table 3, the product with a precise ratio of 25 mg / ml carboxymethyl chitosan and 15 mg / ml sodium glycerophosphate can pass smoothly through the sterile filter membrane and retain the highest dynamic viscosity, thus maximizing the effectiveness of joint cavity filling.

[0035] Comparative Example 2: Rheological data of precisely formulated formulations and commercially available products The formulation of Example 1 was compared with commercially available product 1 (Liposil, manufactured by Shanghai Qisheng Biological Reagents Co., Ltd., batch number M2501CG21) and commercially available product 2 (KiOmed). vs One (manufactured by KiOed Pharma SA, batch number 14KA231025) was tested for its elastic modulus and viscous modulus at 2.5 Hz at 25°C. The results are shown in Table 4 below. Table 4. Rheological test results of precisely formulated preparations and commercially available products.

[0036] As can be seen from Table 4, compared with commercially available carboxymethyl chitosan products, the gel formulation provided by this invention, which is a high-concentration filtered and sterilized carboxymethyl chitosan with a precise ratio of sodium glycerophosphate, has higher elastic modulus and viscous modulus, and can be adapted to different clinical application fields. In particular, it is significantly superior to commercially available carboxymethyl chitosan products in the field of minimally invasive joint filling and repair.

[0037] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the collagen shoulder and cuff patch of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions described in the foregoing embodiments, and such modifications or substitutions do not depart from the essence of the technical solution of the present invention. The above embodiments are only descriptions of preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Any modifications and improvements without departing from the spirit of the present invention fall within the protection scope of the present invention.

Claims

1. A precisely proportioned biological agent for joint cavity filling of carboxymethyl chitosan and sodium glycerophosphate, characterized in that, The preparation comprises functional components and a sterile physiological buffer solution. The functional components are carboxymethyl chitosan and sodium glycerophosphate. Based on the total volume of the biological agent, the concentration of carboxymethyl chitosan is 25 mg / mL, and the concentration of sodium glycerophosphate is 15 mg / mL. The biological agent is a homogeneous colloidal system formed by physical compounding at room temperature. No exogenous chemical crosslinking agents, preservatives, or artificial synthetic thickeners are added to the system. The biological agent is suitable for filling joint space, lubricating joints, and repairing degenerated cartilage.

2. The precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint filling biological agent according to claim 1, characterized in that, The carboxymethyl chitosan has a degree of deacetylation ≤50%, can be completely dissolved in a sterile aqueous solvent at room temperature, and the system is free of agglomerated particles and insoluble impurities.

3. The precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint cavity filling biological agent according to claim 2, characterized in that, The sodium glycerophosphate mentioned herein is composed of one or a combination of α-sodium glycerophosphate, β-sodium glycerophosphate, or sodium glycerophosphate.

4. The injectable joint cavity filling and repair biological agent according to claim 3, characterized in that, The biological agent was tested at 25°C for 0.25 seconds. -1 The dynamic viscosity at the point is ≥2000 mPa·s; the biological agent is prepared by filtration and sterilization.

5. The method for preparing the joint cavity filling biological agent with precisely proportioned carboxymethyl chitosan and sodium glycerophosphate according to any one of claims 1-4, characterized in that, Includes the following steps: S1. Select medical-grade carboxymethyl chitosan with a degree of deacetylation ≤50%, slowly add it to sterile isotonic physiological buffer water, stir at low speed for 20-30 minutes to completely dissolve the powder, and prepare a uniform and transparent carboxymethyl chitosan aqueous solution with a concentration of 25 mg / mL. The system is free of agglomerated particles and precipitated impurities. S2. Accurately weigh medical-grade sodium β-glycerophosphate and add it to the above carboxymethyl chitosan base solution. Stir continuously for 15-20 minutes until completely mixed. Adjust the volume to stabilize the sodium glycerophosphate concentration in the system at 15 mg / mL to obtain a homogeneous composite solution. S3. After heating the above composite solution to 50-70℃, filter the composite solution with a 0.22μm sterile filter membrane to remove bacteria, let it stand for 5-10 minutes to remove air bubbles, and finally obtain a clear, uniform, and highly fluid joint cavity filling composite preparation, which is then aseptically sealed and stored for later use.

6. The application of the precisely proportioned carboxymethyl chitosan and sodium glycerophosphate joint-filling biological agent according to any one of claims 1-4 in the preparation of a minimally invasive injectable drug for treating osteoarthritis, sports joint injuries, and postoperative joint function repair.

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