JAK inhibitor nano suspension injection and preparation method thereof

Abstract

The invention belongs to the technical field of veterinary pharmaceutical preparations, and discloses a JAK inhibitor nano suspension injection and a preparation method thereof. Each 100 mL of the injection comprises the following components: 80 mL of a pharmaceutical active component, 15-25 g of poloxamer 407, 0.2-1 g of carboxymethyl chitosan, and the balance of water for injection, the active pharmaceutical ingredient exists in the form of a nano suspension; the nano suspension contains the ilunitinib, and the nano suspension contains the ilunitinib. The invention provides a drug delivery system which is high in drug loading capacity and has quick effect and long-acting maintenance effects, so that the slow release of drugs is realized, the lasting time of the drug effect is prolonged, and the defects of difficulty in swallowing, poor compliance and frequent drug delivery of affected dogs caused by existing dosage forms are overcome. The invention aims at solving the problems that the solubility of the ilunitinib in water, an oil phase and an oil-soluble matrix is low and the difficulty in developing a liquid preparation is high, and the ilunitinib injection is prepared and has important clinical value.

Description

Technical Field

[0001] This invention belongs to the field of veterinary drug formulation technology, and specifically relates to a JAK inhibitor nanosuspension injection and its preparation method. Background Technology

[0002] {1-(cyclopropanesulfonyl)-3-[4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl]azacyclobutane-3-yl}acetonitrile (ilunocitinib) is an oral JAK inhibitor that works by selectively inhibiting the activity of the JAK family (JAK1 and JAK3) and blocking the signaling of pro-inflammatory cytokines such as IL-4, IL-13, and IL-31. It has shown good efficacy in controlling itching associated with allergic dermatitis and in the treatment of canine atopic dermatitis. This drug was approved by the FDA in September 2024. The dosage form is tablets. The dosage for affected dogs is 0.6-0.8 mg orally per kg body weight, once daily. The drug is rapidly absorbed (t...). max Approximately 2 hours), short half-life (t 1 / 2 (Approximately 3.29 hours).

[0003] However, ilunocitinib is only available in oral tablet form, which has limitations in treating canine atopic dermatitis. It has low solubility and low drug loading, and requires continuous administration, leading to poor compliance in dogs, especially those with vomiting or difficulty swallowing. Maintaining daily administration is even more challenging, potentially causing fluctuations in efficacy, treatment interruption, and increased burden on pet owners. Furthermore, long-term use carries a high risk of systemic immunosuppression side effects. Patent CN118717746A combines a JAK inhibitor with cypressin to reduce the dosage of the JAK inhibitor, improving efficacy and safety, but it does not solve the problem of frequent administration. Patent WO2024 / 186610A1 discloses a topical solution of a JAK inhibitor, which allows for local administration, but the formulation uses a high concentration of the organic solvent dimethyl sulfoxide (DMSO), at a dosage of 25-50 w / v%, which may lead to adverse reactions and safety risks. Additionally, this formulation is primarily used to control dermatitis in specific areas of the dog (e.g., heat spots) and cannot achieve systemic therapeutic effects. Patent WO2022 / 087515 describes a method for preparing ilunocitinib tablets, which are coated tablets with a specific particle size distribution. Due to the limitations of these tablets, existing technologies cannot effectively overcome the problems of low drug solubility, low drug loading, frequent dosing, poor compliance, high long-term safety risks, complex formulations, and difficulty in industrialization associated with ilunocitinib. There is an urgent need to develop a long-acting ilunocitinib formulation with high drug loading, stable release, and extended dosing intervals to address current clinical application issues and improve compliance, safety, and therapeutic efficacy in dogs. Currently, there are no reports of ilunocitinib injections, and their implementation faces significant technical challenges, such as drug-gel matrix compatibility, nanoparticle stability within the gel matrix, and controllable release behavior.

[0004] Drug nanocrystals are nanoparticles of drugs covered with a stabilizer layer, with a size of less than 1 μm. They are usually prepared in the form of nanosuspensions. The small size of the drug particles increases the effective surface area of ​​the drug. Compared with nano-formulations such as nanoliposomes and solid lipid nanoparticles, nanosuspensions have advantages such as solubilization, high drug loading capacity, simple process, multiple routes of administration, controlled release, and avoidance of toxic side effects caused by a large number of excipients. They are particularly suitable for drugs with poor water solubility. Nanoparticle drug delivery technology is a new field and development direction in pharmaceutical research.

[0005] Thermosensitive in-situ gels for injection refer to drug-loaded systems that exist in injectable liquid form at low temperatures. After administration, in response to changes in body temperature, the drug-loaded system rapidly undergoes a phase transition from liquid to semi-solid gel, forming an in-situ drug reservoir. This drug-loaded system offers advantages such as high drug loading capacity and good stability, as well as high safety, injectable administration, and long-term stable release for clinical use.

[0006] Therefore, how to provide a JAK inhibitor nanosuspension injection and its preparation method is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention proposes a JAK inhibitor nanosuspension injection and its preparation method.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A JAK inhibitor nanosuspension injection, each 100mL of injection contains the following components: 80mL of active pharmaceutical ingredient, 15-25g of poloxamer 407, 0.2-1g of carboxymethyl chitosan, and the remainder is water for injection; The active pharmaceutical ingredient exists in the form of a nano-suspension; the nano-suspension contains ilunocitinib.

[0009] The chemical structural formula of ilunocitinib is shown below: .

[0010] Preferably, each 100mL of injection solution includes the following components: 80mL of active pharmaceutical ingredient, 20g of poloxamer 407, 0.5g of carboxymethyl chitosan, and the remainder is water for injection.

[0011] Preferably, each 100 mL of the active pharmaceutical ingredient includes the following raw materials: ilunocitinib 6-15 g, PVP K30 0.5-1.2 g, SDS 0.1-0.5 g, and the balance is water for injection.

[0012] Preferably, each 100 mL of the active pharmaceutical ingredient includes the following raw materials: 10 g of ilunocitinib, 0.7 g of PVP K30, 0.2 g of SDS, and the remainder is water for injection.

[0013] This invention also provides a method for preparing the above-mentioned JAK inhibitor nanosuspension injection, comprising the following steps: (1) PVP K30 and SDS were dissolved in water for injection to obtain a stabilizer solution. Iluunocitinib was added and stirred at 500 rpm for 8 min to disperse it evenly in the stabilizer solution. The suspension was transferred to a high-pressure homogenizer and homogenized 5 times at 1100 bar. The remaining amount was replenished with water for injection to obtain the active pharmaceutical ingredient. (2) According to the ratio, at 2-8℃, add poloxamer 407 and carboxymethyl chitosan to the active pharmaceutical ingredient, stir until completely dissolved, adjust the pH with a pH adjuster, and make up the balance with water for injection to obtain the final product.

[0014] Preferably, in step (2), the pH range is adjusted to 5.0-7.5.

[0015] The present invention also provides the application of the above-mentioned JAK inhibitor nanosuspension injection in the preparation of a drug for treating canine atopic dermatitis or allergic dermatitis.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention provides an injection solution with high drug loading capacity, rapid onset of action, and long-lasting maintenance effect. It achieves slow drug release, prolongs the duration of efficacy, and overcomes the drawbacks of existing formulations, such as difficulty swallowing, poor compliance, and frequent dosing in dogs. The nano-suspension solves the problem of insufficient initial release of ilunocitinib due to slow dissolution in the gel matrix, ensuring rapid achievement of effective therapeutic concentrations after administration and meeting the clinical need for rapid itch relief. The thermosensitive gel serves as an ideal drug reservoir, effectively regulating the subsequent diffusion rate of the drug through the encapsulation and confinement of nanoparticles, providing sustained release for up to one month, fundamentally extending the dosing interval from days to months. Nanocrystals ensure rapid onset of action, while the gel matrix achieves long-lasting maintenance.

[0017] 2. This invention overcomes the challenge of low solubility of ilunocitinib in water, oil phase, and oil-soluble matrix, which makes the development of liquid formulations difficult. It prepares an ilunocitinib injection solution, which has important clinical value.

[0018] 3. This invention uses water as the solvent throughout the entire process, significantly improving biocompatibility and better meeting the high standards required for veterinary medication. It avoids the drawbacks of existing JAK inhibitor topical formulations that use organic solvents, which are prone to causing toxic side effects and only act at the administration site, making systemic treatment difficult. Extensive experimental screening yielded a composite gel matrix composed of poloxamer 407 and carboxymethyl chitosan, which forms a stable system with ilunocitinib nanocrystals, ensuring the stability of the formulation during storage and the expected gelation and release behavior after injection.

[0019] 4. The preparation method of this invention has low cost, stable quality, and is suitable for large-scale industrial production. This dosage form is administered subcutaneously once a month, avoiding frequent oral or topical administration, which can greatly reduce pet stress, reduce the medication burden on pet owners, and improve medication compliance. It has significant clinical value and market potential. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings in this description are merely embodiments of the present invention.

[0021] Figure 1 In vitro dissolution curves for different ilunocitinib (n=2).

[0022] Figure 2 The in vitro release curves of different ilunocitinib are shown (n=2). Detailed Implementation

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] The chemical structural formula of ilunocitinib used in this invention is shown below: .

[0025] Examples 1-4: Preparation of ilunocitinib nanosuspensions Table 1 Composition of ilunocitinib nanosuspension

[0026] Preparation method: According to the proportions in Table 1, weigh out PVP K30 and SDS and dissolve them in an appropriate amount of water for injection. Stir to dissolve. Add ilunocitinib raw material (particle size 5-15 micrometers) and stir at 500 rpm for 8 minutes to initially form a suspension. Homogenize the suspension 5 times with a high-pressure homogenizer at 1100 bar. Then add water for injection to make up to the full volume to obtain ilunocitinib nano suspension.

[0027] Examples 5-8: Preparation of ilunocitinib nanosuspension injection Table 2 Composition of ilunocitinib nanosuspension injection

[0028] Preparation method: The nano-suspensions were prepared according to Examples 1-4 above. Based on Examples 1-4, Examples 5-8 were prepared accordingly, specifically as follows: poloxamer 407 and carboxymethyl chitosan were added sequentially to the nano-suspensions according to the proportions in Table 2, at 4°C, and stirred until completely dissolved. The pH was adjusted to the value specified in Table 2 with 0.1 mol / L NaOH solution or 1 mol / L HCl solution, and water for injection was added to the total volume to obtain ilunocitinib nano-suspension injection.

[0029] I. Evaluation of the external properties of nano-suspension liquids (1) Determination of in vitro dissolution of nano-suspension liquid: Using the slurry method described in Appendix 0931 of the 2020 edition of the Chinese Veterinary Pharmacopoeia, ilunocitinib raw material (20 mg), ilunocitinib nanosuspension prepared according to the method in Example 2 (containing 20 mg of ilunocitinib), and ilunocitinib nanosuspension that had been stored for 90 days were added to 900 mL of phosphate buffer (pH 6.8) containing 0.1% Tween 80. The temperature was (37±0.5) °C and the rotation speed was 75 r. min -1 Samples (5 ml) were taken at 10 min, 15 min, 20 min, 30 min, 45 min, 60 min, 90 min, and 120 min (with the addition of an equal volume of fresh medium at the same temperature). After filtration through a 0.22 μm filter membrane, the concentration of iluconocitinib was determined by HPLC. The cumulative dissolution rate was calculated, and in vitro dissolution curves were plotted. (See figure...) Figure 1 n=2. The cumulative dissolution of ilunocitinib raw material was only about 38% after 2 hours. The nano suspension had better dissolution performance, with a cumulative dissolution of about 92% after 20 minutes. Moreover, the dissolution did not change significantly after 90 days. The dissolution was about 91.56% after 20 minutes and 99.52% after 2 hours, indicating complete release.

[0030] (2) Stability study of nano-suspension: The ilunocitinib nanosuspensions prepared in Examples 1-4 were dispensed into vials and placed under accelerated conditions (40℃±2℃, relative humidity 25%±5%) for 3 months. Samples were taken at the end of March to examine the stability of the samples. Table 3. Stability test results of ilunocitinib nanosuspension

[0031] As shown in Table 3, after being placed under accelerated conditions for 3 months, the product properties, particle size, potential and drug content of each prescription sample remained basically unchanged, indicating that the samples prepared under the prescription process conditions have good stability and can be further prepared into other dosage forms.

[0032] II. Evaluation of the External Properties of Nano-Suspension Injection Liquid Gel temperature determination: The gelation temperature was determined using the inverted test tube method. The water bath temperature was initially controlled at 20°C, and increased by 1°C every 2 minutes. The sample was placed in a glass vial and inverted once every minute. The gelation temperature was defined as the temperature at which the sample did not flow when inverted and remained stable for approximately 30 seconds. Each formulation sample was measured three times using this method, and the average value was taken.

[0033] Gelation time determination: Take a 10mm inner diameter stoppered test tube, seal the mouth of the test tube with a rubber stopper, punch a hole in the rubber stopper and insert a thermometer with an accuracy of 0.1℃, ensuring that the thermometer bulb is completely immersed in the gel solution. Then add 4 mL of sample to the test tube and tighten the rubber stopper. Place the test tube in a water bath at 37℃. At regular intervals, remove the test tube and rotate it to a horizontal position, observing the gelation phenomenon. Record the time required for gelation to occur. Repeat the measurement three times for each sample and take the average value.

[0034] Thermal reversibility test: The gel is heated to a specific temperature (35, 40, 45, 50, 55, 60 and 70 °C) and held for 5 minutes, then slowly cooled to room temperature. This is counted as one heating cycle. The number of cycles required until the gel loses its temperature sensitivity or its composition changes is tested. If the temperature sensitivity is not lost after 10 repetitions, it is recorded as >10 cycles.

[0035] Release rate determination: A coarse particle suspension of ilunocitinib was prepared, comprising the following ingredients per 100 mL: 10 g ilunocitinib, 0.7 g PVP K30, 0.2 g SDS, with the remainder being water for injection. The ingredients were sheared and homogenized at 10,000 rpm for 20 min to obtain the final product.

[0036] Preparation of ilunocitinib in situ gel: Mix 8g of ilunocitinib, 20g of poloxamer 407 and 0.5g of carboxymethyl chitosan evenly, add 80mL of water for injection and stir until evenly dispersed, then add water for injection to make up to 100mL.

[0037] Take 2 mL each of the ilunocitinib nanosuspension injection, ilunocitinib coarse particle suspension, and ilunocitinib in situ gel from Examples 5-8, add them to a flat-bottomed container, gel at 37°C, then add 900 mL of physiological saline and rotate at 50 rpm. -1 Samples (5 mL) were taken at 0.5, 1, 2, 3, 5, 8, 12, 16, 20, 25, and 30 days (with replenishment of the same volume of fresh medium at the same temperature). After filtration through a 0.22 μm filter membrane, the concentration of iluconocitinib was determined by HPLC. The cumulative release was calculated, and in vitro release curves were plotted. (See attached figure.) Figure 2 n=2.

[0038] The coarse-particle suspension of ilunocitinib raw material releases relatively quickly, reaching release equilibrium by day 4, but the drug release is incomplete. The single ilunocitinib in situ gel releases less in the first 8 days, only about 50%, and then releases significantly, accumulating to about 90% by day 16. The sustained-release effect is short and the release is unstable. Examples 5-8 all release steadily and slowly. Among them, Example 5 releases slightly faster, accumulating to 90.53% by day 20 and 95.17% by day 30. Examples 6-8 show a similar trend, with a cumulative release of over 93% by day 30, all meeting the requirement of sustained release for one month.

[0039] Table 4. Evaluation results of the external performance of ilunocitinib nanosuspension injection liquid.

[0040] As shown in Table 4, ilunocitinib nanosuspension injection has a gelation temperature between 34-37℃, can completely form a gel within 30 seconds, has a stable pH value, stable product properties, is a liquid with good fluidity at room temperature, can quickly form a gel after subcutaneous injection, has a significant sustained-release effect, and can be released in vitro for up to 30 days.

[0041] The above embodiments are only used to illustrate the technical solutions 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 can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A JAK inhibitor nanosuspension injection, characterized in that, Each 100 mL injection solution includes the following ingredients: 80 mL of the pharmaceutical active ingredient, 15-25 g of poloxamer 407, 0.2-1 g of carboxymethyl chitosan, and the balance being water for injection. The pharmaceutical active ingredient is in the form of a nanosuspension, and the nanosuspension contains ilunocitinib.

2. The JAK inhibitor nanosuspension injection of claim 1, wherein the JAK inhibitor is selected from the group consisting of tofacitinib, filgotinib, and upadacitinib. Each 100 mL injection solution includes the following ingredients: 80 mL of the pharmaceutical active ingredient, 20 g of poloxamer 407, 0.5 g of carboxymethyl chitosan, and the balance being water for injection.

3. The JAK inhibitor nanosuspension injection of claim 1, wherein the JAK inhibitor is selected from the group consisting of ruxolitinib, momelotinib, fedratinib, pacritinib, and combinations thereof. Each 100 mL of the pharmaceutical active ingredient includes the following raw materials: 6-15 g of ilunocitinib, 0.5-1.2 g of PVP K30, 0.1-0.5 g of SDS, and the balance being water for injection.

4. The JAK inhibitor nanosuspension injection according to claim 3, characterized in that, Each 100 mL of the pharmaceutical active ingredient includes the following raw materials: 10 g of ilunocitinib, 0.7 g of PVP K30, 0.2 g of SDS, and the balance being water for injection.

5. A process for the preparation of a JAK inhibitor nanosuspension injection according to any one of claims 1 to 4, characterized in that, The method includes the following steps: (1) Dissolve PVP K30 and SDS in water for injection to obtain a stabilizer solution, add ilunocitinib, stir at a speed of 500 rpm for 8 min, uniformly disperse in the stabilizer solution, transfer the suspension to a high-pressure homogenizer, cycle homogenize 5 times at 1100 bar, and make up the balance with water for injection to obtain the pharmaceutical active ingredient; (2) According to the proportion, add poloxamer 407 and carboxymethyl chitosan to the pharmaceutical active ingredient at 2-8°C, stir until completely dissolved, adjust the pH with a pH adjuster, and make up the balance with water for injection.

6. The method for preparing a JAK inhibitor nanosuspension injection according to claim 5, characterized in that, The pH range in step (2) is adjusted to 5.0-7.

5.

7. Use of the JAK inhibitor nanosuspension injection of any one of claims 1-4 in the preparation of a medicament for treating canine atopic dermatitis or allergic dermatitis.

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