Inflammation-responsive drug-loaded microgel system with sustained-release property

Abstract

The application relates to the technical field of medicines, and discloses an inflammation response type drug-loaded microgel system with a slow-release characteristic. A construction method of the inflammation response type drug-loaded microgel system with the slow-release characteristic comprises the following steps: taking a solvent I in which active pharmaceutical ingredients and carrier small molecules are dissolved as an oil phase, taking an aqueous solution II containing an emulsifier as a water phase, mixing the two to form oil-in-water type emulsion drops; after the oil-in-water type emulsion drops are generated, the organic solvent in the emulsion drops is removed, liquid drop contraction is realized, and the carrier small molecules and the active pharmaceutical ingredients self-assemble to form drug-loaded gel microspheres in the liquid drop contraction process. The above-mentioned inflammation response type drug-loaded microgel system with the slow-release characteristic is used to effectively encapsulate the active pharmaceutical ingredients in nanofibers, prevent the active pharmaceutical ingredients from being leaked in advance, improve the stability and bioavailability of the drugs, the drug-loaded gel microspheres have an enzyme response release mechanism, can be released on demand, and the residence time is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medicine, in particular to an inflammation-responsive drug-loaded microgel system with sustained-release properties. BACKGROUND

[0002] Local administration injection, such as intra-articular injection, intravitreal injection, and intratympanic injection, can improve drug bioavailability and reduce systemic toxicity. However, this administration method faces a major challenge: the drug is rapidly cleared after injection, limiting its therapeutic effect. To address this issue, scientists have developed various local drug delivery systems, including liposomes, micelles, polymeric micro / nanoparticles, and hydrogels. These drug delivery systems are designed to extend the half-life and release time of drugs, but each has its advantages and disadvantages.

[0003] Although these local drug delivery systems have made some progress in extending the half-life and improving the release characteristics of drugs, they still have some common problems. The most significant problem is that these systems usually undergo an initial rapid release (burst release) followed by a slow and sustained release phase. This release pattern can result in an initial high drug concentration, causing severe adverse reactions such as local irritation, inflammation, or systemic toxicity. In the subsequent release phase, the drug concentration rapidly decreases, which may not maintain an effective therapeutic concentration, affecting the therapeutic effect.

[0004] An ideal local drug delivery system should have the following characteristics:

[0005] 1) Biological responsiveness: able to adjust drug release according to specific stimuli in the body (such as pH, temperature, enzyme concentration, etc.), ensuring that the drug is released at an effective therapeutic concentration when needed.

[0006] 2) On-demand release: able to adjust the release rate and amount of drugs according to the severity of the disease and individual differences of patients to achieve the best therapeutic effect.

[0007] 3) Prolonged residence time: able to reduce unnecessary drug release during disease remission, thereby prolonging the residence time of drugs in the local area and improving sustained therapeutic effect.

[0008] 4) High stability and biocompatibility: the drug delivery system should have high physical and chemical stability and good biocompatibility to avoid adverse reactions or toxicity in the body.

[0009] In recent years, amphiphilic small molecule materials have become one of the research hotspots due to their unique self-assembly ability and good biocompatibility. These materials can self-assemble into nanofiber or microgel structures under specific conditions, effectively encapsulate drug molecules, and release drugs under biological stimulation, exhibiting excellent sustained-release properties and inflammation response ability. Therefore, to solve the above technical problems, the present application provides an inflammation response type drug-loaded microgel system with sustained-release properties. SUMMARY

[0010] The purpose of the present application is to provide an inflammation response type drug-loaded microgel system with sustained-release properties, which effectively encapsulates active pharmaceutical ingredients in nanofibers, prevents premature leakage, improves the stability and bioavailability of drugs, and at the same time, the drug-loaded gel microspheres have an enzyme-responsive release mechanism, can release on demand, and prolong the residence time.

[0011] To achieve the above purpose, the present application provides a construction method of an inflammation response type drug-loaded microgel system with sustained-release properties, comprising the following steps:

[0012] Step 1, emulsification: dissolving active pharmaceutical ingredients and carrier small molecules in solvent I as oil phase, and dissolving emulsifier in water II as water phase, mixing the two to form oil-in-water emulsion droplets;

[0013] Step 2, self-assembly: after the formation of oil-in-water emulsion droplets, remove the organic solvent in the emulsion droplets to realize the shrinkage of the droplets, and in the process of droplet shrinkage, the carrier small molecules and active pharmaceutical ingredients self-assemble to form drug-loaded gel microspheres.

[0014] Further, the volume ratio of the water phase and the oil phase in step 1 is 1:2-20.

[0015] Further, the method of emulsification in step 1 includes one or more of ultrasonic, mechanical stirring, high-pressure homogenization, membrane emulsification, and continuous flow; and the method of removing the organic solvent in the emulsion droplets in step 2 includes one or more of continuous flow, rotary evaporation, and electrostatic spraying.

[0016] Further, the active pharmaceutical ingredient in step 1 is a fatty acid modified prodrug, and the carrier small molecule is an amphiphilic small molecule gel.

[0017] Further, the fatty acid prodrug structure is A-ester bond-B; wherein A comprises one or a mixture of several of tacrolimus, cyclosporine A, sirolimus, everolimus, azathioprine, leflunomide, mycophenolic acid, mycophenolate mofetil, dexamethasone, prednisone, prednisolone, methylprednisolone, hydrocortisone, cortisone, fludrocortisone, betamethasone, triamcinolone, triamcinolone acetonide, flunisolide, beclomethasone, fluticasone, mometasone, flumethasone, isoflupredone, corticosterone, deoxycorticosterone acetate, deoxycorticosterone enanthate, 11-deoxycorticosterone, 11-deoxycortisol, aldosterone, budesonide, docetaxel, methotrexate, etoposide, fulvestrant, paricalcitol, teniposide, paclitaxel, valrubicin, lamivudine, zidovudine, abacavir, emtricitabine, atazanavir, cobicistat, elvitegravir, ribavirin, albendazole, baclofen, benznidazole, nifurtimox, mefloquine, sulfadoxine, pyrimethamine, chloroguanide, amprenavir, amphotericin B, bexarotene, calcitriol, digoxin, doxercalciferol, dronabinol, propofol, 6-mercaptopurine, 1-thyroxine, glibenclamide, helenalactone, tauroursodeoxycholic acid, ruxolitinib, tofacitinib, lisinopril, amlodipine, lidocaine, paliperidone, clarithromycin, clindamycin hydrochloride, fluconazole, rapamycin, perindopril, liraglutide;

[0018] B comprises one or a mixture of several of palmitic acid, butyric acid, hexanoic acid, octanoic acid, decanoic acid, lauric acid, myristic acid, stearic acid, oleic acid, palmitoleic acid, linoleic acid, a-linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid. Further, the amphiphilic small molecule gelator comprises one or a mixture of several of ascorbyl palmitate, ascorbyl decanoate, ascorbyl laurate, ascorbyl octanoate, ascorbyl myristate, ascorbyl oleate, sorbitan monostearate, sorbitan decanoate, sorbitan laurate, sorbitan oleate, sorbitan myristate, tripalmitin, trilaurin, trioctanoin, sucrose palmitate, sucrose decanoate, sucrose laurate, sucrose octanoate, sucrose myristate, and sucrose oleate.

[0019] Further, the solvent I in step 1 comprises one or a mixture of several of benzene, n-butanol, carbon tetrachloride, chloroform, cyclohexane, cyclopentane, dichloromethane, dichloroethane, ethyl acetate, diethyl ether, n-heptane, n-hexane, methyl ethyl ketone, isooctane, pentane, dipropyl ether, tetrachloroethane, toluene, trichloroethane, dimethylbenzene, or dimethyl carbonate.

[0020] Further, the emulsifier in step 1 includes one or several of oleic acid soap, stearic acid soap, lauric acid soap, rosin oil soap, alkyl sulfate, alkyl benzene sulfonate, alkyl sulfonate, alkyl naphthyl sulfonate, lignin sulfonate, phosphate, sulfate, quaternary ammonium salt, alkyl ammonium salt, lecithin, fatty acid glyceride, polyvinyl alcohol, sucrose fatty acid ester, fatty acid sorbitan, polysorbate, polyoxyethylene fatty acid ester, polyoxyethylene fatty alcohol ether, polyoxyethylene-polyoxypropylene block copolymer, fluorocarbon surfactant, silicon-containing surfactant, biological surfactant, crown ether type surfactant, gum arabic, gum tragacanth, gelatin, apricot kernel gum, egg yolk, polyvinylpyrrolidone, or a mixture of solid microparticle emulsifiers.

[0021] The application also provides an inflammation-responsive drug-loaded microgel system with sustained-release characteristics, which is obtained according to the above construction method, and is a drug-loaded gel microsphere.

[0022] The application also provides application of the above inflammation-responsive drug-loaded microgel system with sustained-release characteristics in construction of a drug delivery platform.

[0023] The application has the following advantages and positive effects:

[0024] 1. The application uses amphiphilic small molecules as carrier materials, which self-assemble into nanofibers through hydrophobic interaction, hydrogen bonding and π-π conjugation. In the self-assembly process, fatty acid modified prodrug molecules are effectively encapsulated in the nanofiber structure, preventing premature leakage of active drug molecules. This structure can effectively protect drug molecules, improve drug stability and bioavailability.

[0025] 2. The drug-loaded gel microspheres in the application have an enzyme-responsive release mechanism. The amphiphilic small molecule gel contains cleavable chemical bonds (such as ester bonds), which are cleaved under the action of enzymes (such as esterases, matrix metalloproteinases, etc.) in the body, releasing active drug ingredients. The release rate of active drugs is related to the concentration of enzymes. Injecting or implanting the drug-loaded microgel with sustained-release characteristics into the joint can achieve long-term release of active drugs. The severity of arthritis affects the concentration of enzymes in the joint. When the joint is inflamed and releases enzymes, the enzymes decompose the microgel particles, thereby releasing anti-inflammatory drugs. After the release of anti-inflammatory drugs, the concentration of enzymes decreases, and the un-cleaved microgel remains stable before the next inflammation stimulus, thereby achieving on-demand drug release. The drug-loaded microgel can be used for the release of therapeutic agents for tissue regeneration at different stages, and is suitable for joint cavity, inner ear, eye and oral drug delivery.

[0026] 3、The inflammation-responsive drug-loaded microgel system described in the present application realizes efficient drug delivery and controllable release through advanced material design and microgel preparation process, has important application prospects and wide market demand, and its inflammation-responsive characteristics and sustained-release effect make it have important clinical value in the treatment of chronic diseases (such as arthritis, eye inflammation, inner ear diseases and tumors). In addition, the system can also be used in the field of tissue regeneration, and by releasing the therapeutic agents required in different stages, the repair and regeneration of tissues are promoted.

[0027] The technical solutions of the present application are further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Figure is a self-assembly mechanism diagram of the carrier molecule and the drug molecule in the embodiment of the present application;

[0029] Figure 2 Figure is an optical microscope photo of the microgel prepared in Example 1 of the present application;

[0030] Figure 3 Figure is the drug release curve of the microgel prepared in Example 1 of the present application in PBS solution and 100 U / mL lipase;

[0031] Figure 4 Figure is the drug release curve of the microgel prepared in Example 1 of the present application in 200 U / mL lipase, and under the condition of changing lipase concentration. DETAILED DESCRIPTION

[0032] The technical solutions of the present application are further described in detail below through the accompanying drawings and examples.

[0033] Unless otherwise defined, the technical terms or scientific terms used in the present application shall be understood as the usual meaning understood by those skilled in the art to which the present application belongs.

[0034] Unless otherwise defined, the instruments, devices and reagents used in the present application are all conventional commercially available.

[0035] A method for constructing an inflammation-responsive drug-loaded microgel system with sustained-release characteristics, comprising the following steps:

[0036] Step 1, emulsification: dissolving active drug ingredients and carrier small molecules in solvent I as oil phase, and dissolving emulsifier in water II as water phase, and mixing the two to form oil-in-water emulsion droplets.

[0037] The volume ratio of water phase to oil phase is 1:2-20, and the emulsification method includes one or more of ultrasonic, mechanical stirring, high-pressure homogenization, membrane emulsification and continuous flow.

[0038] The active pharmaceutical ingredient is a fatty acid prodrug, the structure of which is A-ester bond-B,

[0039] A includes one or a mixture of several of tacrolimus, cyclosporin A, sirolimus, everolimus, azathioprine, leflunomide, mycophenolic acid, mycophenolate mofetil, dexamethasone, prednisone, prednisolone, methylprednisolone, hydrocortisone, cortisone, flurandrenolide, betamethasone, triamcinolone acetonide, flunisolide, beclomethasone, fluticasone, mometasone, flumethasone, isoflupredone, corticosterone, deoxycorticosterone acetate, deoxycorticosterone enanthate, 11-deoxycorticosterone, 11-deoxycortisol, aldosterone, budesonide, docetaxel, methotrexate, etoposide, fulvestrant, paricalcitol, teniposide, paclitaxel, valrubicin, lamivudine, zidovudine, abacavir, emtricitabine, atazanavir, cobicistat, elvitegravir, ribavirin, albendazole, baclofen, benznidazole, nifurtimox, mefloquine, sulfadoxine, ethylmercury, chloroguanide, amprenavir, amphotericin B, bexarotene, calcitriol, digoxin, doxercalciferol, dronabinol, propofol, 6-mercaptopurine, 1-thyroxine, glibenclamide, helenalactone, tauroursodeoxycholic acid, ruxolitinib, tofacitinib, lisinopril, amlodipine, lidocaine, paliperidone, clarithromycin, clindamycin hydrochloride, fluconazole, rapamycin, perindopril, liraglutide.

[0040] B includes one or a mixture of several of palmitic acid, butyric acid, caproic acid, caprylic acid, lauric acid, myristic acid, stearic acid, oleic acid, palmitoleic acid, linoleic acid, alpha-linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid.

[0041] The carrier small molecule is an amphiphilic small molecule gel, and the amphiphilic small molecule gel includes one or a mixture of several of ascorbyl palmitate, ascorbyl decanoate, ascorbyl laurate, ascorbyl octanoate, ascorbyl myristate, ascorbyl oleate, sorbitan monostearate, sorbitan decanoate, sorbitan laurate, sorbitan oleate, sorbitan myristate, tripalmitin, trilaurin, trioctanoin, sucrose palmitate, sucrose decanoate, sucrose laurate, sucrose octanoate, sucrose myristate, and sucrose oleate.

[0042] The solvent I includes one or a mixture of several of benzene, n-butanol, carbon tetrachloride, chloroform, cyclohexane, cyclopentane, dichloromethane, dichloroethane, ethyl acetate, diethyl ether, n-heptane, n-hexane, methyl ethyl ketone, isooctane, pentane, dipropyl ether, tetrachloroethane, toluene, trichloroethane, xylene, or dimethyl carbonate.

[0043] The emulsifiers include one or more of oleic acid soap, stearic acid soap, lauric acid soap, rosin oil soap, alkyl sulfate, alkyl benzene sulfonate, alkyl sulfonate, alkyl naphthyl sulfonate, lignin sulfonate, phosphate ester, sulfate ester, quaternary ammonium salt, alkyl ammonium salt, lecithin, fatty acid glyceride, polyvinyl alcohol, sucrose fatty acid ester, fatty acid sorbitan, polysorbate, polyoxyethylene fatty acid ester, polyoxyethylene fatty alcohol ether, polyoxyethylene-polyoxypropylene block copolymer, fluorocarbon surfactant, silicon-containing surfactant, biosurfactant, crown ether-type surfactant, gum arabic, gum tragacanth, gelatin, apricot kernel gum, egg yolk, polyvinylpyrrolidone, or a mixture of one or more of solid microparticle emulsifiers.

[0044] Step 2, self-assembly: after the formation of the oil-in-water emulsion droplets, the organic solvent in the emulsion droplets is removed to realize the shrinkage of the droplets, and in the process of the shrinkage of the droplets, the carrier small molecules and the active pharmaceutical ingredient self-assemble to form the drug-loaded gel microspheres. The self-assembly mechanism of the carrier molecules and the drug molecules is shown in Figure 1

[0045] The method for removing the organic solvent in the emulsion droplets includes one or more of continuous flow, rotary evaporation, and electrostatic spraying.

[0046] The inflammation-responsive drug-loaded microgel system obtained by the construction method is a drug-loaded gel microsphere, the particle size of the drug-loaded gel microsphere is 1 μm-500 μm, the effective components of the drug-loaded gel microsphere include an active pharmaceutical ingredient and a carrier small molecule for controlling the release of the drug, the mass of the active pharmaceutical ingredient accounts for 5-50% of the drug-loaded gel microsphere, and the encapsulation rate of the active pharmaceutical ingredient is 5-100%.

[0047] The following is specifically described by way of examples.

[0048] Example 1: triamcinolone acetonide palmitate (10 mg / mL) and ascorbic acid palmitate (10 mg / mL) are dissolved in ethyl acetate as the oil phase. An aqueous solution containing 1% polyoxyethylene-polyoxypropylene block copolymer is configured as the water phase. The two phases are emulsified by a continuous flow device to form an O / W emulsion by using a syringe pump, the organic solvent in the emulsion is rapidly removed in a pipeline filled with 1% polyoxyethylene-polyoxypropylene block copolymer aqueous solution, and the emulsion droplets are solidified into microspheres. The microspheres are collected in a beaker, washed with ultrapure water, and dried to obtain the product. Compared with the traditional stirring or ultrasonic emulsification method, the continuous flow can provide more stable and moderate energy input, so that the drug molecules and the carrier molecules in the droplets can self-assemble in a more stable environment, which is conducive to improving the stability of the system. The drug loading of the prepared microspheres is 45.51%, and the encapsulation rate is 91.02%. The optical microscope photo of the microspheres is shown in Figure 2

[0049] ​​Example 2: Budesonide palmitate (10 mg / mL) and ascorbyl palmitate (10 mg / mL) were dissolved in chloroform as the oil phase. An aqueous solution containing 1% polyoxyethylene-polyoxypropylene block copolymer was prepared as the water phase. The two phases were emulsified into O / W emulsion by a continuous flow device with the organic solvent in the emulsion being rapidly removed in a pipeline filled with 1% polyoxyethylene-polyoxypropylene block copolymer aqueous solution, and the emulsion droplets solidified into microspheres. The microspheres were collected in a beaker, washed with ultrapure water, and dried to obtain the product. The drug loading of the prepared microspheres was 41.67%, and the encapsulation efficiency was 83.34%.

[0050] Drug release determination was performed on the microspheres prepared in Example 1:

[0051] Figure 3 The drug release curve of the ascorbyl palmitate microspheres containing triamcinolone acetonide palmitate prepared under the conditions of Example 1 in PBS solution and 100 U / mL lipase. The results showed that the prepared microspheres had good stability under physiological conditions of PBS, and showed slow release in the presence of 100 U / mL lipase.

[0052] Figure 4 The drug release curve of the ascorbyl palmitate microspheres containing triamcinolone acetonide palmitate prepared under the conditions of Example 1 in 200 U / mL lipase, and under the condition of changing lipase concentration (5 days). The results showed that the prepared microspheres showed a responsive release to the severity of the disease. In the acute phase of simulated inflammation, i.e. under the condition of higher concentration of lipase, the drug release rate was accelerated. While in the interval period of inflammation after the acute phase, the drug release rate was slowed down. It showed that the drug-loaded gel microspheres in the present application had an enzyme-responsive release mechanism, and could release on demand, prolonging the residence time.

[0053] Therefore, the present application uses the above-mentioned inflammation-responsive drug-loaded microgel system with sustained-release properties, effectively encapsulates the active pharmaceutical ingredients in nanofibers, prevents premature leakage, improves the stability and bioavailability of the drug, and at the same time, the drug-loaded gel microspheres have an enzyme-responsive release mechanism, can release on demand, and prolong the residence time.

[0054] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can still be modified or replaced by equivalents, and these modifications or equivalent replacements should not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present application.

Claims

1. A method for constructing an inflammatory-responsive drug-loaded microgel system with sustained-release properties, characterized in that, Includes the following steps: Step 1, Emulsification: Solvent I, containing dissolved active drug components and carrier small molecules, is used as the oil phase, and aqueous solution II, containing emulsifier, is used as the aqueous phase. The two are mixed to form oil-in-water emulsion droplets. The active pharmaceutical ingredient is a fatty acid-modified prodrug, and the carrier molecule is an amphiphilic small molecule gelling agent; The fatty acid-modified prodrug has an A-ester bond-B; where A is either triamcinolone or budesonide; B is palmitic acid; and the amphiphilic small molecule gelling agent is ascorbyl palmitate. Step 2, self-assembly: After the formation of oil-in-water emulsion droplets, the organic solvent in the droplets is removed to achieve droplet shrinkage. During the droplet shrinkage process, the carrier small molecules and the active drug components self-assemble to form drug-loaded gel microspheres.

2. The construction method according to claim 1, characterized in that: In step 1, the volume ratio of the aqueous phase to the oil phase is 1:2-20.

3. The construction method according to claim 1, characterized in that: The emulsification method in step 1 includes one or more of ultrasonication, mechanical stirring, high-pressure homogenization, membrane emulsification, and continuous flow; the method for removing organic solvents from the emulsion droplets in step 2 includes one or more of continuous flow, rotary evaporation, and electrostatic spraying.

4. The construction method according to claim 1, characterized in that: In step 1, solvent I includes one or a mixture of several of the following: benzene, n-butanol, carbon tetrachloride, chloroform, cyclohexane, cyclopentane, dichloromethane, dichloroethane, ethyl acetate, diethyl ether, n-heptane, n-hexane, methyl ethyl ketone, isooctane, pentane, dipropyl ether, tetrachloroethane, toluene, trichloroethane, xylene, or dimethyl carbonate.

5. The construction method according to claim 1, characterized in that: The emulsifier in step 1 includes one or a mixture of several of the following: oleic acid soap, stearic acid soap, lauric acid soap, rosin oil soap, alkyl sulfate, alkylbenzene sulfonate, alkyl sulfonate, alkylnaphthalene sulfonate, lignin sulfonate, phosphate ester salt, sulfate ester salt, quaternary ammonium salt, alkyl ammonium salt, lecithin, fatty acid glycerides, polyvinyl alcohol, sucrose fatty acid ester, fatty acid sorbitan, polysorbate, polyoxyethylene fatty acid ester, polyoxyethylene fatty alcohol ether, polyoxyethylene-polyoxypropylene block copolymer, fluorocarbon surfactant, silicone surfactant, biosurfactant, crown ether surfactant, gum arabic, tragacanth gum, gelatin, apricot gum, egg yolk, polyvinylpyrrolidone, or solid particulate emulsifier.

6. An inflammatory-responsive drug-loaded microgel system with sustained-release properties, characterized in that: According to the construction method of any one of claims 1-5, the inflammatory-responsive drug-loaded microgel system is a drug-loaded gel microsphere, the particle size of the drug-loaded gel microsphere is 1μm-500μm, the effective components of the drug-loaded gel microsphere include active drug components and carrier small molecules that control drug release, the mass of the active drug components accounts for 5-50% of the drug-loaded gel microspheres, and the encapsulation rate of the active drug components is 5-100%.

7. The application of the inflammatory-responsive drug-loaded microgel system with sustained-release properties as described in claim 6 in the construction of a drug delivery platform.

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