Triamcinolone acetonide sustained-release microspheres for injection (with special solvent) and preparation method and application thereof

Abstract

The application discloses triamcinolone acetonide sustained-release microspheres for injection (with special solvent) and a preparation method and application thereof. It is found through experiments that the triamcinolone acetonide sustained-release microspheres prepared by the method have higher stability, a longer effective period, more gentle release, longer maintenance time of drug efficacy and a significantly longer release period, and have a wide clinical application prospect in the field of osteoarthritis treatment.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, specifically relating to a sustained-release triamcinolone acetonide microsphere for injection (with a special solvent), its preparation method, and its application. Background Technology

[0002] Osteoarthritis (OA), a common chronic degenerative joint disease, has complex causes and its pathology often involves degeneration and damage to articular cartilage. It affects various tissues surrounding the joint, such as articular cartilage, subchondral bone, synovium, and ligaments. The main symptoms are progressive joint pain, swelling, stiffness, and even joint deformity, characterized by cartilage matrix degradation. It commonly affects all joints, large and small, throughout the body. Guidelines recommend three main treatment methods: non-pharmacological treatment, pharmacological treatment, and surgical treatment. Pharmacological treatment includes oral analgesics, nonsteroidal anti-inflammatory drugs (NSAIDs), glucosamine, and chondroitin sulfate, primarily for pain relief. However, long-term use of NSAIDs increases the risk of cardiovascular and gastrointestinal diseases. Surgery is the final treatment for OA, but it carries risks such as postoperative infection and is expensive.

[0003] Since the 1950s, intra-articular injection of anti-inflammatory drugs has become one of the most effective treatments for osteoarthritis. This therapy delivers the drug directly to the affected joint, avoiding systemic toxicity and altering the drug's distribution throughout the body. While highly effective, injection therapy still has limitations. After administration, the active ingredient rapidly penetrates the systemic circulation, resulting in a short residence time within the joint cavity, leading to frequent injections and a painful treatment process. Therefore, sustained-release formulations for intra-articular injection have become a research hotspot in this field. Triamcinolone acetonide (TCA) is a corticosteroid with anti-inflammatory, antipruritic, and vasoconstrictive effects. It has good therapeutic effects on joint pain, swelling, stiffness, and diffuse arthritis, with minimal water and sodium retention and a strong and long-lasting anti-inflammatory effect.

[0004] In addition, triamcinolone has certain effects in treating tissue hyperplasia. It can affect the formation and development of hyperplastic tissue through multiple mechanisms: (1) Suppressing the immune response: Triamcinolone can interfere with the macrophage-mediated inflammatory response, thereby suppressing the immune response and reducing excessive tissue proliferation. (2) Anti-inflammatory effect: This drug can reduce the production of pro-inflammatory factors such as leukotrienes, exert an anti-inflammatory effect, and reduce the inflammatory response of tissues. (3) Promoting collagen decomposition: Triamcinolone can inhibit fibroblast activity and affect collagen synthesis, thereby promoting collagen decomposition and helping to soften scar tissue. (4) Inhibiting fibroblast proliferation: Triamcinolone can directly or indirectly inhibit the growth and activity of fibroblasts and reduce the formation of hyperplastic tissue. (5) Antipruritic effect: Triamcinolone also has an antipruritic effect and can relieve the discomfort caused by hyperplasia.

[0005] Currently, the triamcinolone acetonide sustained-release injection suspension (ZILRETTA) available overseas is a microsphere prepared by loading triamcinolone acetonide onto a poly(lactic-co-glycolic acid) (PLGA) copolymer. Intra-articular injection is used to treat pain caused by arthritis, with an effective duration of up to three months. The poly(lactic-co-glycolic acid) copolymer is a copolymer of lactide and glycolide in a specific ratio. It is a biodegradable functional polymer organic compound with good biocompatibility, non-toxicity, and excellent encapsulation and film-forming properties, and is widely used in pharmaceuticals, medical engineering materials, and modern industrial fields. Patent CN103260603A (application number: 201180047943.4, invention title: corticosteroids for treating joint pain) discloses the preparation process of ZILRETTA, whose microsphere carrier is PLGA. The preparation process is as follows: PLGA with a molar ratio of lactide and glycolide of 75:25 is used. The dispersion is atomized into tiny droplets by a rotating disk using a solvent evaporation method. The solvent is evaporated to produce solid microparticles. The microparticles are collected by a cyclone separator and then filtered through a 150μm sieve. The microparticles prepared by this method have a wide particle size distribution, low yield, and short drug release cycle. Summary of the Invention

[0006] In view of this, in order to overcome the technical problems existing in the prior art, the purpose of the present invention is to provide a sustained-release microsphere for injection of triamcinolone acetonide (with a special solvent) and its preparation method and application. The sustained-release microsphere for injection of triamcinolone acetonide prepared by the method provided by the present invention has higher stability, longer shelf life, smoother release, longer duration of drug effect, ≥70% cumulative release in 120h, and significantly longer release cycle.

[0007] The above-mentioned objective of this invention is achieved through the following technical solution:

[0008] A first aspect of the present invention provides triamcinolone acetonide sustained-release microspheres for injection.

[0009] Furthermore, the injectable triamcinolone acetonide sustained-release microspheres use triamcinolone acetonide as the active ingredient and lactide-glycolic acid copolymer as the carrier, wherein the drug loading is 15-25%, and the molar ratio of lactide to glycolide in the lactide-glycolic acid copolymer is (80-95:5-20).

[0010] Furthermore, the molecular weight of the lactide-glycol copolymer is 10,000-100,000;

[0011] Preferably, the injectable triamcinolone acetonide sustained-release microspheres have a D10 ≥ 20 μm, a D50 = 35-80 μm, and a D90 ≤ 150 μm;

[0012] Preferably, the SPAN of the triamcinolone acetonide sustained-release microspheres for injection is ≤2.0;

[0013] Preferably, the cumulative release of the triamcinolone acetonide sustained-release microspheres for injection is ≤10% after 2 hours, ≤40% after 12 hours, ≤55% after 24 hours, and ≥70% after 120 hours.

[0014] Preferably, the weight-average molecular weight of the triamcinolone acetonide sustained-release microspheres for injection is 10,000-100,000, and the distribution coefficient D ≤ 2.5.

[0015] Furthermore, the triamcinolone acetonide sustained-release microspheres for injection are white or off-white powders.

[0016] Furthermore, the injectable triamcinolone acetonide sustained-release microspheres can be used for the effective treatment of osteoarthritis and / or tissue hyperplasia.

[0017] In this invention, triamcinolone acetonide (TCA) is an adrenocortical hormone drug with the chemical formula C. 24 H 31 FO6, with a molecular weight of 434.49 and CAS No. 76-25-5, possesses anti-inflammatory, antipruritic, and vasoconstrictive effects. It has a good therapeutic effect on joint pain, joint swelling, stiffness, and diffuse arthritis, with weak water and sodium retention effects and strong and long-lasting anti-inflammatory effects. It also has a certain effect in treating tissue hyperplasia.

[0018] In this invention, the lactide-glycolic acid copolymer (PLGA) is a copolymer formed by copolymerizing lactide and glycolide in a certain proportion, and its molecular formula is C0. 10 H 12O8, with a molecular weight of 260.1975 and CAS No. 26780-50-7, is a biodegradable functional high-molecular organic compound with good biocompatibility, non-toxicity, and good encapsulation and film-forming properties. It is widely used in pharmaceuticals, medical engineering materials, and modern industrial fields.

[0019] In some embodiments, the molar ratio of lactide to glycolide in the lactide-glycol copolymer of the present invention is (80-95:5-20), and the molecular weight is 10,000-100,000.

[0020] In some embodiments, the residual amount of dichloromethane in the triamcinolone acetonide sustained-release microspheres for injection shall not exceed 0.06%, and the moisture content shall not exceed 1.0%.

[0021] A second aspect of the present invention provides a triamcinolone acetonide sustained-release microsphere suspension for injection.

[0022] Furthermore, the suspension comprises the triamcinolone acetonide sustained-release microspheres and a special solvent as described in the first aspect of the present invention.

[0023] Furthermore, the special solvent includes sodium carboxymethyl cellulose, sodium chloride, polysorbate 80, and purified water;

[0024] Preferably, the dosages of sodium carboxymethyl cellulose, sodium chloride, polysorbate 80, and purified water are (0.45%-0.55%), (0.85%-0.95%), (0.09%-0.10%), and (98.35%-98.65%), respectively.

[0025] Preferably, the dosages of sodium carboxymethyl cellulose, sodium chloride, polysorbate 80, and purified water are 0.50%, 0.90%, 0.10%, and 98.50%, respectively.

[0026] Preferably, the pH value of the suspension is 6.0-8.0;

[0027] Preferably, the osmolar concentration of the suspension is 260-350 mOsmol / kg.

[0028] In some embodiments, the dedicated solvent is a sterile aqueous solution containing sodium chloride, sodium carboxymethyl cellulose, and polysorbate 80. The sodium chloride (NaCl) content is 0.85-0.95% (g / g). It is a colorless, clear liquid with a pH of 6.0-8.0 and a dynamic viscosity of 3-30 mPa·s at 25°C.

[0029] A third aspect of the present invention provides a method for preparing the triamcinolone acetonide sustained-release microspheres for injection described in the first aspect of the present invention.

[0030] Furthermore, the method includes the following steps:

[0031] (1) Preparation of continuous phase: Polyvinyl alcohol is added to water and dissolved to obtain a homogeneous solution, which is the continuous phase;

[0032] (2) Preparation of dispersed phase: First, triamcinolone acetonide is suspended in dichloromethane, and then lactide-glycolic acid copolymer is added and dissolved in dichloromethane containing triamcinolone acetonide to obtain dispersed phase;

[0033] (3) Preparation of microspheres: The dispersed phase is dispersed into the continuous phase by passing the dispersed phase through the membrane emulsification membrane tube under a certain pressure using the membrane emulsification method. After the microspheres are solidified, they are washed and dried with purified water or cooled water for injection to obtain microsphere intermediates. The microsphere intermediates are then subjected to surface treatment by medium A and medium B, and then washed and dried to obtain the triamcinolone acetonide sustained-release microspheres for injection as described in the first aspect of the present invention.

[0034] Furthermore, the dosage of polyvinyl alcohol used in step (1) is (0.05%-0.15%);

[0035] Preferably, the dosage of polyvinyl alcohol used in step (1) is 0.10%;

[0036] Preferably, the dosage of water used in step (1) is (99.85%-99.95%);

[0037] Preferably, the dosage of water used in step (1) is 99.90%.

[0038] Furthermore, in step (2), the weight ratio of the dosage of triamcinolone acetonide to the dosage of lactide-glycolic acid copolymer is 1:2.3-1:3.0;

[0039] Preferably, the weight ratio of the dosage of triamcinolone acetonide to the dosage of lactide-glycolic acid copolymer in step (2) is 1:3.0;

[0040] Preferably, the solid-liquid ratio of the dosage of the lactide-glycolic acid copolymer to the dosage of dichloromethane in step (2) is 0.30-0.40 g / mL;

[0041] Preferably, the dosage of the lactide-glycolic acid copolymer used in step (2) is 0.35 g / mL in a solid-liquid ratio with the dosage of dichloromethane.

[0042] Furthermore, the pressure described in step (3) is 8-20 psi;

[0043] Preferably, the temperature of the continuous phase in step (3) is 8-15°C.

[0044] Preferably, the medium A in step (3) comprises sodium dihydrogen phosphate dihydrate, sodium hydroxide, sodium dodecyl sulfate, polysorbate 80, and purified water (or water for injection);

[0045] More preferably, the dosages of sodium dihydrogen phosphate dihydrate, sodium hydroxide, sodium dodecyl sulfate, and polysorbate 80 are (1.50-1.60 g / L), (0.02-0.03 g / L), (2.00-4.00 g / L), and (4.50-6.50 g / L), respectively, and purified water (or water for injection) is added to the total volume;

[0046] Preferably, the medium B in step (3) comprises sodium acetate, glacial acetic acid, and purified water (or water for injection);

[0047] More preferably, the dosages of sodium acetate and glacial acetic acid used are (17-19 g / L) and (9-11 g / L) respectively, and purified water (or water for injection) is added to the total volume;

[0048] Preferably, in step (3), the concentration of medium A is 1-2 g / L, the treatment temperature is 42-48℃, and the time is 20-60 min; the concentration of medium B is 1-2 g / L, the treatment temperature is 48-52℃, and the time is 15-60 min.

[0049] More preferably, the treatment concentration of medium A is 2 g / L, the treatment temperature is 45°C, and the treatment time is 30 min; the treatment concentration of medium B is 2 g / L, the treatment temperature is 50°C, and the treatment time is 20-30 min.

[0050] Preferably, the drying temperature in step (3) is 30-40°C.

[0051] Furthermore, the present invention also provides a method for treating and / or preventing osteoarthritis and / or tissue hyperplasia, the method comprising the steps of administering to a subject in need a therapeutic and / or preventative effective amount of the triamcinolone acetonide sustained-release microspheres for injection as described in the first aspect of the present invention, and / or the triamcinolone acetonide sustained-release microsphere suspension as described in the second aspect of the present invention.

[0052] In this invention, the treatment and / or prevention refers to the act of preventing and reducing the occurrence or development of a disease, thereby inhibiting, suppressing, alleviating, improving, slowing down, stopping, delaying, or reversing the progression or aggravation of the disease. The various indicators of maintaining and / or using the medication include alleviating or reducing the symptoms or complications of a specific disease, or curing or eliminating the disease, disorder, or condition. Therefore, the treatment and / or prevention described in this invention include preventing, alleviating, and / or treating the disease (e.g., osteoarthritis or its related symptoms).

[0053] In this invention, the effective amount refers to the dose at which one or more compounds (e.g., triamcinolone acetonide sustained-release microspheres for injection as described in the first aspect of this invention, and / or triamcinolone acetonide sustained-release microsphere suspension as described in the second aspect of this invention) are administered to achieve a specific pharmacological effect. It should be emphasized that a therapeutically effective amount is not always effective in achieving the expected effect in a given subject, even if the dose is considered therapeutically effective by those skilled in the art. Those skilled in the art can adjust such a dose according to standard practice required to treat a specific subject. The therapeutically effective amount can vary based on the route of administration and dosage form, the age and weight of the subject, and / or the severity of the subject's condition. For example, those skilled in the art will understand that a therapeutically effective amount for treating a small individual may differ from a therapeutically effective amount for treating a large individual.

[0054] In this invention, when the application is directed to an animal, human, subject, cell, tissue, organ, or biological fluid, it refers to the contact between an exogenous drug and the animal, human, subject, cell, tissue, organ, or biological fluid. Application can refer to, for example, therapeutic, pharmacokinetic, research, and experimental methods. Cell treatment includes contact between a reagent and a cell, as well as contact between a reagent and a fluid. Application also means treating cells in vitro and ex vivo with a reagent, composition, or another cell, and when said treatment is applied to a human, veterinary, or research subject, it refers to therapeutic treatment, preventative or preventative measures, research, or other applications.

[0055] In this invention, the subject refers to any animal, including both human and non-human animals. Non-human animals include all vertebrates, such as mammals, including non-human primates (especially higher primates), sheep, dogs, rodents (such as mice or rats), guinea pigs, goats, pigs, cats, rabbits, cattle, and any livestock or pets; as well as non-mammals, such as chickens, amphibians, reptiles, etc. In a specific embodiment of this invention, the subject is preferably a human.

[0056] A fourth aspect of the invention provides the application of the media A and / or media B as described above in the surface treatment of microspheres;

[0057] Optionally, the microspheres are triamcinolone acetonide sustained-release microspheres.

[0058] The fifth aspect of the present invention provides the use of the triamcinolone acetonide sustained-release microspheres for injection described in the first aspect of the present invention, and / or the triamcinolone acetonide sustained-release microsphere suspension described in the second aspect of the present invention, in the preparation of medicaments for the treatment and / or prevention of osteoarthritis and / or tissue hyperplasia.

[0059] Furthermore, the osteoarthritis includes knee osteoarthritis, hip osteoarthritis, ankle osteoarthritis, interphalangeal osteoarthritis, wrist osteoarthritis, elbow osteoarthritis, spinal osteoarthritis, rheumatoid arthritis, acute gouty arthritis, or synovitis;

[0060] Preferably, the tissue hyperplasia includes hyperplasia caused by excessive stimulation of endocrine hormones or local inflammatory factors.

[0061] In some embodiments, the drug may contain pharmaceutical excipients. These excipients can be those conventionally used in various formulations, including but not limited to: diluents, binders, surfactants, humectants, adsorbents, lubricants, fillers, disintegrants, etc.; or they can be selected for compatibility with the substance, including but not limited to: emulsifiers, solubilizers, antibacterial agents, analgesics, and antioxidants. These excipients can effectively improve the stability and solubility of the active ingredient contained in the drug or change the release rate and absorption rate of the active ingredient, thereby improving the metabolism of the active ingredient in the body and enhancing the drug's administration effect. Furthermore, excipients may be used to achieve specific administration purposes or methods, such as: sustained-release administration, controlled-release administration, and pulsatile administration, including but not limited to: gelatin, albumin, chitosan, polyethers, and polyester polymers (e.g., polyethylene glycol, polyurethane, polycarbonate, and their copolymers). The main benefits of improved administration include: enhanced therapeutic effect, improved bioavailability, reduced toxicity and side effects, and improved patient compliance.

[0062] In some implementations, the diluent includes, but is not limited to, lactose, sodium chloride, glucose, urea, starch, water, etc.

[0063] In some embodiments, the adhesive includes, but is not limited to: starch, pregelatinized starch, dextrin, maltodextrin, sucrose, gum arabic, gelatin, methylcellulose, carboxymethylcellulose, alginate and alginate, xanthan gum, hydroxypropyl cellulose, etc.

[0064] In some embodiments, the surfactant includes, but is not limited to, sodium dodecyl sulfate, glyceryl monostearate, hexadecyl alcohol, etc.

[0065] In some embodiments, the humectant includes, but is not limited to, glycerin, starch, etc.

[0066] In some embodiments, the adsorbent carrier includes, but is not limited to, starch, lactose, bentonite, soap clay, etc.

[0067] In some embodiments, the lubricant includes, but is not limited to, zinc stearate, talc, calcium and magnesium stearate, polyethylene glycol, polyoxyethylene monostearate, monolaurate, etc.

[0068] In some embodiments, the filler includes, but is not limited to, mannitol, xylitol, sorbitol, maltose, glucose, lactose, sucrose, dextrin, starch, etc.

[0069] In some embodiments, the disintegrant includes, but is not limited to: crosylvinylpyrrolidone, sodium carboxymethyl starch, low-substituted hydroxypropylmethyl, crosylcarboxymethyl cellulose sodium, soybean polysaccharides, etc.

[0070] In some embodiments, the pharmaceutical excipients may additionally contain liquids such as water, saline, glycerin, and ethanol. Additionally, auxiliary substances such as wetting agents, emulsifiers, or pH buffers may be present in the drug. These carriers enable the drug to be formulated into a suspension for patient ingestion.

[0071] In some embodiments, the triamcinolone acetonide sustained-release microsphere suspension and drug provided by the present invention are administered locally. In some embodiments, the triamcinolone acetonide sustained-release microsphere suspension and drug can be administered locally, for example, by injection into or near the patient's painful area, in the intra-articular space, periarticular space, soft tissue, lesion, epidural space, perineural space, or foramen space.

[0072] In some embodiments, the triamcinolone acetonide sustained-release microsphere suspension and drug provided by the present invention are administered by injection. In some embodiments, the triamcinolone acetonide sustained-release microsphere suspension and drug can be injected into the intra-articular space or soft tissue by a single injection or sequential injection to alleviate, prevent, reverse or inhibit symptoms associated with the progression of osteoarthritis.

[0073] Compared with the prior art, the present invention has the following advantages:

[0074] (1) Compared with the triamcinolone acetonide sustained-release injection suspension ZILRETTA disclosed in patent CN103260603B, the triamcinolone acetonide sustained-release microspheres for injection prepared by the present invention have higher stability, longer shelf life, smoother release, longer duration of drug effect, ≥70% cumulative release in 120h, and significantly longer release cycle, achieving technical effects that are not expected by those skilled in the art based on the prior art.

[0075] (2) Compared with the triamcinolone acetonide sustained-release microspheres for injection disclosed in patent CN113476410A and the triamcinolone acetonide sustained-release microspheres disclosed in patent CN112972401B, the triamcinolone acetonide sustained-release microspheres for injection prepared by the present invention have a smoother in vitro release and a longer sustained-release period, achieving technical effects that are not expected by those skilled in the art based on the prior art.

[0076] (3) Compared with commercially available triamcinolone acetonide injection, the triamcinolone acetonide sustained-release microspheres for injection prepared in this invention exhibit better sustained-release effect. The sustained-release effect of the triamcinolone acetonide sustained-release microspheres for injection prepared in this invention can be maintained in vivo for at least 90 days, which is significantly better than commercially available triamcinolone acetonide injection. In addition, the highest blood drug concentration of the triamcinolone acetonide sustained-release microspheres for injection prepared in this invention is 60 times lower than that of commercially available triamcinolone acetonide injection, indicating that the triamcinolone acetonide sustained-release microspheres for injection prepared in this invention can provide a longer-lasting drug effect, while significantly reducing the side effects of corticosteroids on the system, achieving technical effects that those skilled in the art could not have predicted based on the prior art. Attached Figure Description

[0077] Figure 1 The cumulative release curves of triamcinolone acetonide sustained-release microspheres obtained using different process parameters are shown below. The curves below correspond to the triamcinolone acetonide sustained-release microspheres prepared in Example 1 and the triamcinolone acetonide sustained-release microspheres prepared in Example 2. The curve at the top corresponds to the FDA-approved commercial triamcinolone acetonide sustained-release injection suspension ZILRETTA.

[0078] Figure 2 The in vitro release curves of the triamcinolone acetonide sustained-release microspheres prepared in Example 1 of the present invention, the triamcinolone acetonide sustained-release microspheres prepared in Example 2 of the present invention, the FDA-approved commercially available triamcinolone acetonide sustained-release injection suspension ZILRETTA, the triamcinolone acetonide sustained-release microspheres disclosed in patent CN112972401B, and the triamcinolone acetonide sustained-release microspheres for injection disclosed in patent CN113476410A are shown.

[0079] Figure 3 The average blood concentration and time curves of triamcinolone acetonide sustained-release microspheres and commercially available triamcinolone acetonide injection prepared in Example 1 of this invention in rats. Detailed Implementation

[0080] The present invention will be further illustrated below with reference to specific embodiments. These specific embodiments are for illustrative purposes only and should not be construed as limiting the invention. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the invention. The scope of the invention is defined by the claims and their equivalents.

[0081] The drugs, reagents and raw materials used in this invention are readily available to those skilled in the art and can be obtained commercially unless otherwise specified. Experimental methods not specified in this invention are generally performed under conventional conditions or according to the manufacturer's recommendations. In particular, the following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention in any way.

[0082] Example 1: Preparation process of triamcinolone acetonide sustained-release microspheres for injection

[0083] 1. Triamcinolone Acetonide Sustained-Release Microspheres for Injection

[0084] Preparation of continuous phase: Dissolve 500.00g of polyvinyl alcohol in 50L of water at 75℃ to obtain a homogeneous solution, which is the continuous phase.

[0085] Preparation of the dispersed phase: First, 70.00 g of triamcinolone acetonide was suspended in 600 mL of dichloromethane. Then, 210.00 g of lactide-glycolic acid copolymer (PLGA) (85:15) (for injection) was added and dissolved in 600 mL of dichloromethane containing triamcinolone acetonide.

[0086] Microsphere preparation: The dispersed phase was forced through an SPG membrane emulsification tube with a pore size of 50 / 50 / 50 μm at a pressure of 8-20 psi using a membrane emulsification method, and dispersed into a continuous phase at 12.8℃. The solvent was then evaporated, and the microspheres were solidified.

[0087] Collect and clean the microspheres.

[0088] 2. Drying and collecting

[0089] After filtration and drying, the intermediate of triamcinolone acetonide sustained-release microspheres for injection was collected.

[0090] 3. Microsphere surface treatment

[0091] The above-mentioned microsphere intermediate was treated with medium A at 45℃ for 30 min and medium B at 50℃ for 30 min, with a treatment concentration of 2 g / L in both cases. After treatment, the microspheres were washed, dried, and sieved to obtain triamcinolone acetonide sustained-release microspheres for injection.

[0092] The medium A comprises sodium dihydrogen phosphate dihydrate, sodium hydroxide, sodium dodecyl sulfate, polysorbate 80, and purified water (or water for injection); the dosages of sodium dihydrogen phosphate dihydrate, sodium hydroxide, sodium dodecyl sulfate, and polysorbate 80 are (1.50-1.60 g / L), (0.02-0.03 g / L), (2.00-4.00 g / L), and (4.50-6.50 g / L), respectively, and purified water (or water for injection) is added to the total volume.

[0093] The medium B comprises sodium acetate, glacial acetic acid, and purified water (or water for injection); the dosages of sodium acetate and glacial acetic acid are (17-19 g / L) and (9-11 g / L), respectively, and purified water (or water for injection) is added to the full volume.

[0094] The sustained-release microspheres for injection have a drug loading of 20.70%.

[0095] It is a white or off-white powder.

[0096] Particle size and particle size distribution are shown in Table 1 below, and release rate is shown in Table 2 below.

[0097] Table 1 Particle size and particle size distribution

[0098]

[0099] Table 2 Release Rate

[0100]

[0101] Weight-average molecular weight (M w The value is 49989, and the distribution coefficient D(M) is... w / M n The content of dichloromethane was 1.45; the residual amount of dichloromethane was 0.027%; the moisture content was 0.56%; and the content uniformity was 14.13.

[0102] 3. Special solvent

[0103] Add 400 mL of purified water (80% of the prescribed volume), then add 2.50 g of sodium carboxymethyl cellulose and stir until completely dissolved. Next, add 4.50 g of sodium chloride and 0.50 g of polysorbate 80, stirring until completely dissolved. Adjust the volume to 500 mL. Filter. Fill 5.0-5.5 mL / vial (5.22-5.53 g / bottle). Crim the cap.

[0104] 4. Triamcinolone Acetonide Sustained-Release Microsphere Suspension for Injection

[0105] The microspheres described above are suspended in the aforementioned specialized solvent to obtain a sustained-release triamcinolone acetonide microsphere suspension for injection. The suspension has a pH of 6.0-8.0 and an osmolar concentration of 260-350 mOsmol / kg. The final product contains the aforementioned sustained-release triamcinolone acetonide microspheres for injection and the aforementioned specialized solvent. This product, after suspension, is used for intra-articular injection to treat pain associated with knee osteoarthritis.

[0106] Example 2: Preparation process of triamcinolone acetonide sustained-release microspheres for injection

[0107] 1. Triamcinolone Acetonide Sustained-Release Microspheres for Injection

[0108] Preparation of continuous phase: Dissolve 50.00g of polyvinyl alcohol in 5L of water at 80℃ to obtain a homogeneous solution, which is the continuous phase.

[0109] Preparation of the dispersed phase: First, 13.33 g of triamcinolone acetonide was suspended in 100 mL of dichloromethane. Then, 40.00 g of lactide-glycolic acid copolymer (PLGA) (85:15) (for injection) was added and dissolved in 100 mL of dichloromethane containing triamcinolone acetonide.

[0110] Microsphere preparation: The dispersed phase is forced through a three-stage emulsification membrane tube with pore sizes of 100 (stainless steel membrane tube) / 50 / 50 μm at a pressure of 8-20 psi by membrane emulsification, and dispersed into a continuous phase at 10.0℃. The solvent is then evaporated, and the microspheres are solidified.

[0111] Collect and clean the microspheres.

[0112] 2. Drying and collecting

[0113] After filtration and drying, the intermediate of triamcinolone acetonide sustained-release microspheres for injection was collected.

[0114] 3. Microsphere surface treatment

[0115] The microsphere intermediate was treated with medium A at 45°C for 30 min and medium B at 50°C for 20 min, with a treatment concentration of 2 g / L. After treatment, the microspheres were washed, dried, and sieved to obtain triamcinolone acetonide sustained-release microspheres for injection.

[0116] The sustained-release microspheres for injection have a drug loading of 18.98%.

[0117] It is a white or off-white powder.

[0118] Particle size and particle size distribution are shown in Table 3 below, and release rate is shown in Table 4 below.

[0119] Table 3 Particle size and particle size distribution

[0120]

[0121] Table 4 Release Rate

[0122]

[0123] Weight-average molecular weight (M w The value is 42638, and the distribution coefficient D(M) is... w / M n The value is 1.39.

[0124] Comparative Example 1: Comparison of the triamcinolone acetonide sustained-release microspheres prepared in this invention with the triamcinolone acetonide sustained-release injection suspension ZILRETTA disclosed in patent CN103260603B, the triamcinolone acetonide sustained-release microspheres for injection disclosed in patent CN113476410A, and the triamcinolone acetonide sustained-release microspheres disclosed in patent CN112972401B.

[0125] 1. Experimental Methods

[0126] (1) The preparation steps of ZILRETTA according to the method disclosed in patent CN103260603A are as follows: 250 mg of triamcinolone acetonide and 750 mg of PLGA (lactide:glycolic acid molar ratio of 75:25, intrinsic viscosity of 0.27 dL / g, and molecular weight of 29 kDa) are dispersed in 14.25 g of dichloromethane. The dispersion is atomized into microdroplets by adding it to the feed hole of a rotating disc maintained at a temperature of approximately 3300 rpm within a temperature control range of 38–45 °C. The solvent is evaporated to produce solid microparticles. The microparticles are collected using a cyclone separator and then filtered through a 150 μm sieve to obtain ZILRETTA. A comparison of the preparation processes is shown in Table 5 below.

[0127] Table 5 Comparison of the preparation processes of the triamcinolone acetonide sustained-release microspheres for injection and ZILRETTA prepared according to the present invention

[0128] process ZILRETTA Triamcinolone acetonide sustained-release microspheres for injection (with dedicated solvent) lactide: glycolide molar ratio 75:25 85:15 Solid-liquid ratio (g / mL) 1.075 0.35、0.40 Preparation method Solvent evaporation method, rotating disk Solvent evaporation method, membrane emulsifier Emulsification temperature (°C) 38-45 8-15

[0129] (2) According to the specific preparation steps of the triamcinolone acetonide sustained-release microsphere implant disclosed in patent CN113476410A: Take 33g of triamcinolone acetonide, 10g of PLGA (molecular weight 55kDa), and mix them evenly with 30mL of dichloromethane at a molar ratio of lactide: glycolide 85:15 (intrinsic viscosity 0.44dl / g). The mixture is then passed through a 30μm pore size SPG membrane emulsification tube at a pressure of 15psi and dispersed into 5L of 1% PVA solution containing 0.05% PEG4000. The solvent is evaporated by magnetic stirring at room temperature and pressure. After the microspheres are solidified, they are washed with ethanol and water, washed with 0.05% PEG4000, washed with pure water, filtered, and dried to obtain the finished triamcinolone acetonide sustained-release microspheres.

[0130] (3) According to the specific preparation steps of triamcinolone acetonide sustained-release microspheres disclosed in patent CN112972401B: 20g PLGA was dissolved in dichloromethane, 8.6g triamcinolone acetonide was uniformly dispersed in the PLGA-dichloromethane solution to form a dispersed phase, 50g polyvinyl alcohol and 1g sodium carboxymethyl cellulose were dissolved in 10L of water for injection to form a continuous phase, and the dispersed phase was introduced into the continuous phase through a microfluidic chip using microfluidic technology for curing and drying to obtain triamcinolone acetonide microspheres with uniform particle size. The flow rate of the dispersed phase was 5mL / min and the flow rate of the continuous phase was 50mL / min. The flow rates of the dispersed phase and the continuous phase were adjusted, and the microspheres with regular shapes were observed continuously under a microscope in real time, and the microspheres were cured.

[0131] (4) The release rates of the triamcinolone acetonide sustained-release microspheres for injection prepared in Examples 1 and 2 of this invention, the ZILRETTA described in this comparative example, the triamcinolone acetonide microspheres for injection disclosed in patent CN113476410A, and the triamcinolone acetonide microspheres disclosed in patent CN112972401B were determined according to the dissolution and release rate determination method (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0931, Method II), and the in vitro release effects were compared.

[0132] 2. Experimental Results

[0133] The results are as follows Figure 1 , Figure 2 As shown in Tables 6-10, the results indicate that the release rate of the triamcinolone acetonide sustained-release microspheres for injection prepared in Examples 1 and 2 of this invention, as determined by the dissolution and release rate determination method (Chinese Pharmacopoeia 2020 Edition, Part IV, General Chapter 0931, Method II), is slower and the release period is significantly longer. This indicates that the triamcinolone acetonide sustained-release microspheres prepared in Examples 1 and 2 of this invention have significantly better performance in terms of cumulative release than ZILRETTA disclosed in patent CN103260603A, triamcinolone acetonide sustained-release microspheres for injection disclosed in patent CN113476410A, and triamcinolone acetonide sustained-release microspheres disclosed in patent CN112972401B. This effect is a technical effect that would not have been anticipated by those skilled in the art based on the prior art.

[0134] Table 6. ZILRETTA Release Rate

[0135]

[0136] Table 7 Release rates of the triamcinolone acetonide sustained-release microspheres prepared in Example 1

[0137]

[0138] Table 8 Release rates of the triamcinolone acetonide sustained-release microspheres prepared in Example 2

[0139]

[0140] Table 9 shows the release rates of triamcinolone acetonide sustained-release microspheres for injection disclosed in patent CN113476410A.

[0141]

[0142] Table 10 shows the release rate of triamcinolone acetonide sustained-release microspheres disclosed in patent CN112972401B.

[0143]

[0144] Comparative Example 2: Comparison of in vivo pharmacokinetic data of triamcinolone acetonide sustained-release microspheres for injection prepared in this invention with commercially available triamcinolone acetonide injection in rats.

[0145] 1. Experimental Methods

[0146] The sustained-release triamcinolone acetonide microspheres for injection prepared in Example 1 of this invention were selected as the test sample, and commercially available triamcinolone acetonide injection (Kunming Jida Pharmaceutical Co., Ltd., batch number 220507) was used as the control to investigate the pharmacokinetic characteristics of rats. The administration route was intra-knee injection; the administration frequency was single administration; and the dosage was 0.8 mg (calculated as triamcinolone acetonide) per rat.

[0147] Blood was drawn from the jugular vein of all animals, with approximately 0.22 mL collected from each animal, for pharmacokinetic analysis.

[0148] Blood collection time points were before drug administration, and 15 min, 30 min, 1 h, 2 h, 4 h, 6 h, 8 h, 24 h, 48 h (D3), 168 h (D8), 336 h (D15), 504 h (D22), 672 h (D29), 840 h (D36), 1008 h (D43), 1176 h (D50), 1344 h (D57), 1680 h (D71), and 2160 h (D91) after drug administration.

[0149] 2. Experimental Results

[0150] The results are as follows Figure 3 As shown, in vivo data indicate that, compared to commercially available triamcinolone acetonide injection, the triamcinolone acetonide sustained-release microspheres prepared in Example 1 of this invention exhibit better sustained-release effects. At 840 hours, the blood concentration of the commercially available triamcinolone acetonide injection reference standard was undetectable, while the blood concentration of the triamcinolone acetonide sustained-release microspheres prepared in Example 1 of this invention still reached 3.12 ng / mL at 2160 hours, indicating that in vivo release can be maintained for at least 90 days. Furthermore, the results show that the highest in vivo exposure concentration of the commercially available triamcinolone acetonide injection reference standard reached 849.32 ng / mL, while the highest blood concentration of the triamcinolone acetonide sustained-release microspheres prepared in Example 1 of this invention was 14.14 ng / mL, which is sixty times lower than the commercially available reference standard. This suggests that the triamcinolone acetonide sustained-release microspheres prepared in Example 1 of this invention can provide a more sustained efficacy while significantly reducing the systemic side effects of corticosteroids. Compared to the commercially available triamcinolone acetonide injection disclosed in the prior art, Example 1 of this invention has achieved unexpected technical effects.

Claims

1. A method for preparing triamcinolone acetonide sustained-release microspheres for injection, characterized in that, The method includes the following steps: (1) Preparation of continuous phase: Polyvinyl alcohol is added to water and dissolved to obtain a homogeneous solution, which is the continuous phase; (2) Preparation of dispersed phase: First, triamcinolone acetonide is suspended in dichloromethane, and then lactide-glycolic acid copolymer is added and dissolved in dichloromethane containing triamcinolone acetonide to obtain dispersed phase; (3) Preparation of microspheres: The dispersed phase is dispersed into the continuous phase by passing the dispersed phase through the membrane emulsification membrane tube under certain pressure using the membrane emulsification method. After the microspheres are solidified, they are washed and dried to obtain an intermediate. After surface treatment by medium A and medium B, they are washed, dried, and sieved to obtain triamcinolone acetonide sustained-release microspheres for injection. The dosage of polyvinyl alcohol used in step (1) is (0.05%-0.15%). The dosage of water used in step (1) is (99.85%-99.95%). The molar ratio of lactide to glycolide in the lactide-glycol copolymer described in step (2) is (80-95:5-20). The molecular weight of the lactide-glycol copolymer mentioned in step (2) is 10,000-100,000; The weight ratio of the dosage of triamcinolone acetonide to the dosage of lactide-glycolic acid copolymer in step (2) is 1:2.3-1:3.

0. The dosage of the lactide-glycol copolymer used in step (2) is 0.30-0.40 g / mL in a solid-liquid ratio to the dosage of dichloromethane. The medium A mentioned in step (3) contains sodium dihydrogen phosphate dihydrate, sodium hydroxide, sodium dodecyl sulfate, polysorbate 80, and purified water (or water for injection); The dosages of sodium dihydrogen phosphate dihydrate, sodium hydroxide, sodium dodecyl sulfate, and polysorbate 80 are (1.50-1.60 g / L), (0.02-0.03 g / L), (2.00-4.00 g / L), and (4.50-6.50 g / L), respectively, and purified water (or water for injection) is added to the total volume. The medium B mentioned in step (3) includes sodium acetate, glacial acetic acid, and purified water (or water for injection). The dosages of sodium acetate and glacial acetic acid used are (17-19 g / L) and (9-11 g / L) respectively, and purified water (or water for injection) is added to the total volume; In step (3), the concentration of medium A is 1-2 g / L, the treatment temperature is 42-48℃, and the time is 20-60 min. The concentration of medium B is 1-2 g / L, the treatment temperature is 48-52℃, and the time is 15-60 min.

2. The method according to claim 1, characterized in that, The dosage of polyvinyl alcohol used in step (1) is 0.10%.

3. The method according to claim 1, characterized in that, The dosage of water used in step (1) is 99.90%.

4. The method according to claim 1, characterized in that, The weight ratio of the dosage of triamcinolone acetonide to the dosage of lactide-glycolic acid copolymer in step (2) is 1:3.

0.

5. The method according to claim 1, characterized in that, The solid-liquid ratio of the dosage of lactide-glycolic acid copolymer used in step (2) to the dosage of dichloromethane is 0.35 g / mL.

6. The method according to claim 1, characterized in that, The pressure described in step (3) is 8-20 psi.

7. The method according to claim 1, characterized in that, The temperature of the continuous phase in step (3) is 8-15℃.

8. The method according to claim 1, characterized in that, The treatment concentration of medium A is 2 g / L, the treatment temperature is 45℃, and the treatment time is 30 min. The treatment concentration of medium B is 2 g / L, the treatment temperature is 50℃, and the treatment time is 20-30 min.

9. The method according to claim 1, characterized in that, The drying temperature in step (3) is 30-40℃.

10. A type of sustained-release triamcinolone acetonide microsphere for injection prepared by the method according to any one of claims 1-9.

11. The triamcinolone acetonide sustained-release microspheres for injection according to claim 10, characterized in that, The sustained-release microspheres for injection contain triamcinolone acetonide as the active ingredient and lactide-glycolic acid copolymer as the carrier, wherein the drug loading is 15-25% and the molar ratio of lactide to glycolide in the lactide-glycolic acid copolymer is (80-95:5-20). The molecular weight of the lactide-glycolic acid copolymer is 10,000-100,000; The injectable triamcinolone acetonide sustained-release microspheres have a D10 ≥ 20 μm, a D50 = 35-80 μm, and a D90 ≤ 150 μm. The injectable triamcinolone acetonide sustained-release microspheres have a SPAN ≤ 2.0; The cumulative release of the triamcinolone acetonide sustained-release microspheres for injection is ≤10% at 2 h, ≤40% at 12 h, ≤55% at 24 h, and ≥70% at 120 h. The weight-average molecular weight of the triamcinolone acetonide sustained-release microspheres for injection is 10,000-100,000, and the distribution coefficient D ≤ 2.

5.

12. A sustained-release triamcinolone acetonide microsphere suspension for injection, characterized in that, The suspension comprises the triamcinolone acetonide sustained-release microspheres as described in claim 10 or 11 and a special solvent; The special solvent contains sodium carboxymethyl cellulose, sodium chloride, polysorbate 80, and purified water; The dosages of sodium carboxymethyl cellulose, sodium chloride, polysorbate 80, and purified water are (0.45%-0.55%), (0.85%-0.95%), (0.09%-0.10%), and (98.35%-98.65%), respectively.

13. The suspension according to claim 12, characterized in that, The dosages of sodium carboxymethyl cellulose, sodium chloride, polysorbate 80, and purified water are 0.50%, 0.90%, 0.10%, and 98.50%, respectively.

14. The suspension according to claim 12, characterized in that, The pH value of the suspension is 6.0-8.

0.

15. The suspension according to claim 12, characterized in that, The osmolar concentration of the suspension is 260-350 mOsmol / kg.

16. The use of the triamcinolone acetonide sustained-release microspheres for injection as described in claim 10 or 11, and / or the triamcinolone acetonide sustained-release microsphere suspension as described in any one of claims 12-15, in the preparation of a medicament for the treatment and / or prevention of osteoarthritis and / or tissue hyperplasia.

17. The application according to claim 16, characterized in that, The osteoarthritis mentioned includes knee osteoarthritis, hip osteoarthritis, ankle osteoarthritis, interphalangeal osteoarthritis, wrist osteoarthritis, elbow osteoarthritis, spinal osteoarthritis, rheumatoid arthritis, acute gouty arthritis, or synovitis.

18. The application according to claim 16, characterized in that, The tissue proliferation includes proliferation caused by excessive stimulation of endocrine hormones or local inflammatory factors.

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