Sustained-release injectable composition for treating or preventing inflammatory diseases and method for producing the same

Abstract

The present invention relates to a sustained-release injectable composition for the treatment or prevention of inflammatory diseases and a method for producing the same, which uses cannabidiol-containing microparticles to sustain the release of cannabidiol for more than one month, thereby demonstrating the therapeutic or preventive effect of inflammatory diseases. Furthermore, the sustained-release injectable composition containing cannabidiol is non-toxic, has no side effects due to long-term use, and can be used for a long period of time. A single injection can provide the therapeutic or preventive effect of inflammatory diseases for more than one month, greatly improving the convenience of administration.

Description

[Technical Field]

[0001] The present invention relates to a sustained-release injectable composition for treating or preventing inflammatory diseases and a method for preparing the same. [Background technology]

[0002] Osteoarthritis is a degenerative disease caused by knee cartilage damage and abnormalities in the joint's lubricating fluid. It is characterized by degenerative changes in the cartilage and surrounding bone in synovial joints. Cartilage is the smooth tissue that covers the ends of bones in joints. Healthy cartilage helps absorb the shock generated by bone movement. In osteoarthritis, the upper layer of cartilage breaks down and wears away, allowing the subchondral bone to come into direct contact with the cartilage. This direct contact causes pain, swelling, and loss of joint movement. Over time, the joint can lose its normal shape and lead to osteophytosis. Pieces of bone and cartilage can also break off and become loose within the joint space, causing even more pain and damage.

[0003] People with osteoarthritis often experience joint pain and reduced mobility. Unlike other forms of arthritis, osteoarthritis only affects the joints and not internal organs. Osteoarthritis is the most common type of arthritis; the second most common type is rheumatoid arthritis, which is caused by an abnormality in the autoimmune system.

[0004] Currently, it is known that medication, exercise therapy, and surgery can be used to treat osteoarthritis, and among these, medications such as acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and corticosteroids are used for medication.

[0005] However, most drugs only treat inflammation and relieve pain, and are unable to prevent the underlying cartilage degradation. Rather, they accelerate cartilage damage and have been criticized for their side effects on the cardiovascular system, gastrointestinal tract, kidneys, liver, etc.

[0006] Therefore, there is a need to develop a therapeutic agent for treating or ameliorating osteoarthritis, and a product that can enhance the therapeutic or preventive effect of osteoarthritis by releasing the drug over a long period of time with a single injection. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Korean Patent Publication No. 10-2020-0066281 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a sustained-release injectable composition for treating or preventing inflammatory diseases and a method for preparing the same.

[0009] Another object of the present invention is to provide a sustained-release injectable composition that uses cannabidiol-containing microparticles to sustainedly release cannabidiol for more than one month, thereby demonstrating the effectiveness of treating or preventing inflammatory diseases.

[0010] Another object of the present invention is to provide a sustained-release injectable composition containing cannabidiol that is non-toxic, has no side effects due to long-term use, and can be used for a long period of time, and that can show therapeutic or preventive effects for inflammatory diseases for more than one month with a single injection, and that has greatly improved convenience in administration. [Means for solving the problem]

[0011] To achieve the above objectives, the present invention provides a sustained-release injectable composition for the treatment or prevention of inflammatory diseases, comprising microparticles that release cannabidiol (CBD) continuously for one month or more, the microparticles comprising cannabidiol and a biodegradable polymer.

[0012] The microparticles may contain cannabidiol and a biodegradable polymer in a weight ratio of 1:3 to 1:10.

[0013] The biodegradable polymer can be selected from the group consisting of polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide (PLGA), polyphosphazene, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, and combinations thereof.

[0014] The polylactide-co-glycolide may have a monomer ratio of lactide:glycolide of 60:40 to 90:10.

[0015] The inflammatory disease may be osteoarthritis.

[0016] The microparticles may release 35% to 80% of the total CBD weight after 18 hours in the following release test: [Emission test conditions] The dissolution test solution was prepared by mixing 1 L of 10 mM PBS buffer (pH 7.4) with Tween 20 to a concentration of 0.05% (w / v), and then mixing sodium azide and sodium ascorbate to the mixture to a concentration of 0.02% (w / v) and 0.0625% (w / v), respectively.

[0017] 100 mL of the dissolution test solution was placed in an injection vial, and the microparticles were placed in the vial so that the total weight of the CBD in the microparticles was 15 mg. After the injection vial was completely sealed, the test was performed by maintaining the temperature at 50°C and shaking at a speed of 120 rpm. After 18 hours had passed since the start of dissolution, the injection vial was removed and left for 3 minutes, and then 1 mL of the test solution was accurately taken using a syringe and centrifuged at 3000 rpm for 3 minutes. The supernatant was used as a test liquid to confirm the release of CBD.

[0018] A method for preparing a sustained-release injectable composition for treating or ameliorating inflammatory diseases according to another embodiment of the present invention may include the steps of dissolving cannabidiol (CBD) and a biodegradable polymer in an organic solvent to prepare an oil phase solution, dissolving a surfactant in water to prepare an aqueous phase solution, and mixing the oil phase solution and the aqueous phase solution to form an emulsion.

[0019] The method may further include the steps of: obtaining the prepared emulsion in an aqueous phase solution and removing residual solvent; washing and freeze-drying the emulsion from which the residual solvent has been removed to prepare microparticles; and mixing the freeze-dried microparticles with water for injection.

[0020] The oil phase solution and the aqueous phase solution can be injected into each microchannel and allowed to flow, forming an emulsion containing cannabidiol and a time-release agent at the point where the oil phase solution stream and the aqueous phase solution stream intersect with each other.

[0021] The oil phase solution may additionally contain butylhydroxytoluene (BHT). [Effects of the Invention]

[0022] The present invention uses microparticles containing cannabidiol to sustainedly release cannabidiol for more than one month, demonstrating the effectiveness of treating or preventing inflammatory diseases.

[0023] In addition, the sustained-release injectable composition contains cannabidiol, which is known to have a wide safety margin when exposed to the whole body, has few side effects when used over a long period of time, and can be effective in treating or preventing inflammatory diseases for more than one month with a single injection, greatly improving the convenience of administration. [Brief explanation of the drawings]

[0024] [Figure 1] 1 shows the results of a CBD release experiment for microparticles containing CBD according to one embodiment of the present invention. [Figure 2] 1 shows the results of a pharmacokinetic experiment in rats on microparticles containing CBD according to one embodiment of the present invention. [Figure 3] 1 shows the results of measuring weight change in an osteoarthritis model administered with microparticles containing CBD according to one embodiment of the present invention. [Figure 4] 1 shows the results of measuring lower limb weight bearing in an osteoarthritis model administered with microparticles containing CBD according to one embodiment of the present invention. [Figure 5] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model before administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 6] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 2 hours after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 7] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 4 days after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 8] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 7 days after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 9] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 11 days after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 10] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 14 days after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 11] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 21 days after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 12] 1 shows the results of a paw withdrawal threshold test in an osteoarthritis model 28 days after administration of microparticles containing CBD according to one embodiment of the present invention. [Figure 13] 1 shows the results of a stability evaluation of microparticles containing CBD according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0025] The present invention relates to a sustained-release injectable composition for the treatment or prevention of inflammatory diseases, comprising microparticles that release cannabidiol (CBD) continuously for one month or more, the microparticles comprising cannabidiol and a biodegradable polymer. [Example]

[0026] Although the present invention may be embodied in various different forms, it is not intended to be limited to the embodiments set forth herein, and the present invention is not limited to the embodiments set forth herein.

[0027] The cannabidiol (CBD) of the present invention is a physiologically active substance isolated from cannabis, and can be extracted directly from cannabis, or extracted CBD can be used. It can also be produced by chemical synthesis, and includes all of its salts, but is not limited to the above examples.

[0028] Hemp, also known as hemp, was traditionally used as a fabric for clothing. More specifically, hemp fiber is used for textiles, mosquito nets, ropes, fishing nets, and papermaking, while hemp seeds are used to extract oil for food, kerosene, soap, varnish, and paint, and oil cake is used as animal feed and fertilizer.

[0029] Delta-9-tetrahydrocannabinol (THC), a psychoactive chemical that is one of the main components of cannabis, is derived from the Cannabis sativa or Cannabis indica plant. Commonly referred to as marijuana, it is designated as an illegal drug in some countries. In countries designated as an illegal drug, storing and handling it without special permission is illegal. Another major component is cannabidiol (CBD), which, unlike THC, is known to have no psychoactive effects. Therefore, extensive research has recently been conducted into its use in medicines and cosmetics.

[0030] The World Health Organization (WHO) has released a report stating that cannabidiol (CBD) oil, made from cannabis extract, is effective in treating epilepsy, Alzheimer's disease, and other conditions.

[0031] The World Anti-Doping Agency (WADA) issued the "2018 International Standard Prohibited List," removing CBD from its list of banned substances starting this year. CBD is widely used by athletes for pain management, and while it banned hashish, marijuana, and other substances derived from cannabis, it allowed CBD oil for medical purposes.

[0032] As such, the current situation is that the use of CBD for medical purposes is permitted in a variety of countries.

[0033] However, as mentioned above, when CBD is used for medical purposes, it is used in the form of CBD oil, and in order to treat or prevent certain diseases, it must be taken continuously over long periods of time, and there are currently no dosage forms that make it more convenient to take.

[0034] Therefore, the present invention provides an injectable composition that can be used to treat or prevent inflammatory diseases using CBD, and is particularly characterized by containing microparticles that can release CBD continuously for more than one month with a single injection.

[0035] The microparticles are characterized by containing CBD and a biodegradable polymer.

[0036] Therefore, when the microparticles of the present invention are used as an injection, a single administration can provide a sustained CBD administration effect. Specifically, a single administration can maintain blood CBD concentrations above the effective concentration for one month or more, a single administration can maintain blood CBD concentrations above the effective concentration for several months, a single administration can maintain blood CBD concentrations above the effective concentration for three months, a single administration can maintain blood CBD concentrations above the effective concentration for six months, and a single administration can maintain blood CBD concentrations above the effective concentration for 12 months.

[0037] In other words, it can show a sustained CBD release effect for more than one month, more than three months, more than six months, or more than 12 months.

[0038] The sustained CBD release effect can be influenced by the decomposition rate of the sustained-release agent, i.e., the biodegradable polymer.

[0039] The biodegradable polymer can be selected from the group consisting of polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide (PLGA), polyphosphazene, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, and combinations thereof.

[0040] For example, the molar ratio of glycolide to lactide in polylactide-co-glycolide may be about 40:60 to about 90:10, about 40:60 to about 85:15, about 40:60 to about 80:20, about 40:60 to about 75:25, about 45:55 to about 90:10, or about 45:55 to about 80:20. While not limited to these examples, the molar ratio of glycolide to lactide in polylactide-co-glycolide is preferably about 75:25 or about 50:50. When polylactide-co-glycolide having the above-described molar ratio of glycolide to lactide ranges is used as a sustained-release agent, CBD can be released continuously in the body for more than one month.

[0041] The biodegradable polymer may include one or more polylactides and one or more polylactide-co-glycolides. In the present invention, the biodegradable polymer may include, for example, a combination of two polylactides, one polylactide and one polylactide-co-glycolide, two polylactide-co-glycolides, three polylactides, two polylactides and one polylactide-co-glycolide, or one polylactide and two polylactide-co-glycolides, and particularly, but is not limited to, one polylactide and one polylactide-co-glycolide, or two polylactide-co-glycolides.

[0042] The biodegradable polymer may include two or more types of polylactide-co-glycolides. The biodegradable polymer may include one type of polylactide-co-glycolide and one type of polylactide, but is not limited to these examples. Any biodegradable polymer that can continuously release CBD in the body for one month or more can be used.

[0043] The microparticles may contain CBD and a biodegradable polymer in a weight ratio of 1:3 to 1:10, a weight ratio of 1:3.5 to 1:9.5, or a weight ratio of 1:4 to 1:9. When used as an injectable composition, microparticles containing CBD within these ranges can be used as sustained-release injections that continuously release CBD within an injectable dose range. That is, if the CBD content is less than this range compared to the biodegradable polymer, the amount of the injectable composition increases to achieve the total dose of CBD required for injection, which can result in an injectable amount exceeding the amount of injection that can be administered to a single person. Furthermore, if the CBD content exceeds this range compared to the biodegradable polymer, it is difficult to produce microparticles with uniformly distributed CBD.

[0044] The inflammatory disease may be osteoarthritis, but it can also be used for other inflammatory diseases, and can be applied to all diseases for which the therapeutic or ameliorating effect of CBD on inflammatory diseases has been proven without limitation, but it is preferably used for treating or ameliorating osteoarthritis.

[0045] The microparticles may release 35% to 80% of the total CBD weight after 18 hours in the following release test: [Emission test conditions]

[0046] The dissolution test solution was prepared by mixing 1 L of 10 mM PBS buffer (pH 7.4) with Tween 20 to a concentration of 0.05% (w / v), and then mixing sodium azide and sodium ascorbate to the mixture to a concentration of 0.02% (w / v) and 0.0625% (w / v), respectively.

[0047] 100 mL of the dissolution test solution was placed in an injection vial, and the microparticles were placed in the vial so that the total weight of the CBD in the microparticles was 15 mg. After the injection vial was completely sealed, the test was performed by maintaining the temperature at 50°C and shaking at a speed of 120 rpm. After 18 hours had passed since the start of dissolution, the injection vial was removed and left for 3 minutes, and then 1 mL of the test solution was accurately taken using a syringe and centrifuged at 3000 rpm for 3 minutes. The supernatant was used as a test liquid to confirm the release of CBD.

[0048] The CBD release test was conducted using a dissolution test solution to confirm the sustained release of CBD. As described above, for CBD-containing microparticles to release CBD continuously for one month or more, the test showed that after 18 hours, 35% to 80% of the total CBD weight should be released, 40% to 78%, or 50% to 75%. When CBD is released within these ranges, the microparticles can exhibit a sustained CBD release effect for one month or more. That is, if the CBD is released below these ranges, the initial CBD release effect is too insufficient to demonstrate the therapeutic or ameliorative effects of CBD on inflammatory diseases. If the CBD is released above these ranges, the amount of CBD released is too high to demonstrate a sustained CBD release effect for one month or more.

[0049] The microparticles of the present invention may also additionally contain butylhydroxytoluene (BHT).

[0050] The CBD may be a compound represented by the following chemical formula: [ka]

[0051] CBD, the compound represented by the above chemical formula, is a stable compound that does not oxidize when it comes into contact with oxygen in the air. However, when formulated into microparticles containing biodegradable polymers, as in the present invention, there is a problem that CBD may oxidize.

[0052] When CBD is oxidized as described above, it can turn yellow, as explained above, and the structure of the compound changes due to oxidation, which can result in a decrease in efficacy.

[0053] The butylhydroxytoluene (BHT) is contained in the microparticles to prevent the oxidation of CBD, i.e., the oxidation of cannabidiol can be prevented by oxidizing BHT instead of CBD within the microparticles.

[0054] The microparticles of the present invention are spherical microparticles as described below, and when the solvent is completely removed during the manufacturing process, cannabidiol, a sustained-release agent, and butylhydroxytoluene (BHT) can be uniformly distributed.

[0055] At this time, when the microparticles come into contact with oxygen, an oxidation reaction of CBD occurs, but the oxidation reaction of butylhydroxytoluene (BHT) occurs preferentially compared to the CBD, preventing the oxidation reaction of CBD.

[0056] Although the oxidation reaction of CBD can be prevented by the above-mentioned action, this antioxidant effect is not achieved by antioxidants other than butylhydroxytoluene (BHT). When butylhydroxytoluene (BHT) is included, the butylhydroxytoluene (BHT) is oxidized before the CBD, thereby achieving the antioxidant effect on CBD.

[0057] The butylhydroxytoluene (BHT) may be contained in an amount of 0.11 wt % to 9.9 wt %, 0.2 wt % to 9 wt %, 0.3 wt % to 8 wt %, or 0.5 wt % to 5 wt % based on the total weight of the cannabidiol and biodegradable polymer. Within this range, the BHT can be manufactured into spherical microparticles, maintaining an appropriate CBD content range and allowing for use in sustained-release dosage forms. The anti-oxidation effect of the BHT on the CBD can enhance stability.

[0058] A sustained-release injectable composition containing cannabidiol according to another embodiment of the present invention may include microparticles containing the cannabidiol and a suspension solvent.

[0059] The injectable composition may contain a suspension medium, which contains an isotonic agent, a suspending agent, and a solvent.

[0060] More specifically, the tonicity agent can be selected from the group consisting of D-mannitol, maltitol, sorbitol, lactitol, xylitol, sodium chloride, and mixtures thereof, and is preferably, but not limited to, D-mannitol.

[0061] The suspending agent may be sodium carboxymethylcellulose, polysorbate 80, starch, starch derivatives, polyhydric alcohols, chitosan, chitosan derivatives, cellulose, cellulose derivatives, collagen, gelatin, hyaluronic acid (HA), alginic acid, algin, pectin, carrageenan, chondroitin, chondroitin sulfate, dextran, dextran sulfate, polylysine, titin, fibrin, agarose, fluran, xanthan gum, etc. gum), and mixtures thereof, preferably sodium carboxymethylcellulose and polysorbate 80, but not limited to the above examples.

[0062] The solvent may be water for injection, and any solvent that can be used as water for injection may be used without limitation.

[0063] A method for producing microparticles containing cannabidiol (CBD) according to another embodiment of the present invention may include dissolving CBD and a biodegradable polymer in an organic solvent to prepare an oil phase solution, dissolving a surfactant in water to prepare an aqueous phase solution, and mixing the oil phase solution and the aqueous phase solution to form an emulsion.

[0064] The manufacturing method can form an emulsion using an oil phase solution prepared by dissolving CBD, a release-sustaining agent, and an antioxidant in an organic solvent, and an aqueous phase solution containing a surfactant.

[0065] As will be described later, although the present invention produces the emulsion by a microfluidic method using a microchannel, the production method is not limited to this, and any method for producing microparticles, such as a solvent evaporation method or a membrane method, can be applied.

[0066] The organic solvent can be any solvent that can completely dissolve the CBD and biodegradable polymer. Specifically, it can be any one or more selected from the group consisting of chloroform, chloroethane, dichloroethane, dichloromethane, trichloroethane, methylene chloride, methanol, and mixtures thereof, preferably methylene chloride, methanol, and mixtures thereof. The organic solvent is not limited to the above examples, and any organic solvent that can completely dissolve the CBD and biodegradable polymer can be easily selected by a person skilled in the art.

[0067] The CBD and biodegradable polymer in the organic solvent may be contained in a weight ratio of 1:3 to 1:10, a weight ratio of 1:3.5 to 1:9.5, or a weight ratio of 1:4 to 1:9.

[0068] The biodegradable polymer content in the oil phase solution is 10 to 20 wt %, preferably 12 to 18 wt %, and more preferably 15 wt %, but is not limited to these examples. If the content is less than this range, it is impossible to prepare an emulsion, and if the content is more than this range, the viscosity of the oil phase solution becomes too high, making it difficult to prepare an emulsion.

[0069] The biodegradable polymer is selected from the group consisting of polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide (PLGA), polyphosphazene, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, and combinations thereof, and is preferably polylactide-co-glycolide (PLGA) and / or polylactide (PLA), but is not limited to the above examples.

[0070] The oil phase solution may further contain butylhydroxytoluene (BHT). As described above, the butylhydroxytoluene (BHT) may be contained in the oil phase solution and the microparticles, thereby preventing oxidation of CBD. The butylhydroxytoluene (BHT) may be contained in an amount of 0.11 wt% to 9.9 wt%, 0.2 wt% to 9 wt%, 0.3 wt% to 8 wt%, or 0.5 wt% to 5 wt% based on the total weight of the cannabidiol and biodegradable polymer.

[0071] The surfactant contained in the aqueous phase solution is 0.1 to 1.0% by weight, 0.2 to 0.5% by weight, or may be 0.25% by weight, with the remainder being water.

[0072] The surfactant may be at least one selected from the group consisting of methylcellulose, polyvinylpyrrolidone, lecithin, gelatin, polyvinyl alcohol, sorbitan monooleate (e.g., Span™ 80), polyoxyethylene sorbitan fatty acid ester (e.g., Tween™ 80), polyoxyethylene castor oil derivatives, sodium lauryl sulfate, sodium stearate, esteramine, linear diamine, pattyamine, and mixtures thereof, and is preferably polyvinyl alcohol. However, the surfactant is not limited to the above examples, and any surfactant that can be used to prepare a perfectly spherical emulsion can be used.

[0073] As explained above, after the oil phase solution and the aqueous phase solution are prepared, there is no limitation on the method for preparing an emulsion using them.

[0074] However, in the present invention, a method for producing microparticles by a microfluidic method will be described.

[0075] The microchip for use in the microfluidic method may be formed on a wafer or glass substrate. The microchip has microchannels formed thereon, more specifically, the microchannels include a channel through which an oil phase solution flows, a channel through which an aqueous phase solution flows, and a transfer channel, the channel through which the oil phase solution flows and the channel through which the aqueous phase solution flows are formed to meet each other at one point, and one end of the transfer channel can be connected to the junction of the two channels.

[0076] The channel through which the oil phase solution flows and the channel through which the aqueous phase solution flows are connected to injection sections for injecting the oil phase solution and the aqueous phase solution, respectively, and a recovery section for recovering the solution containing the emulsion can be connected to one end of the transfer channel.

[0077] The microchannel may be formed in a material selected from the group consisting of a glass substrate, a silicon wafer, or a polymer film, but examples of the material are not limited to these examples, and any material capable of forming a microchannel can be used.

[0078] The polymer film may be selected from the group consisting of polyimide, polyethylene, fluorinated ethylene propylene, polypropylene, polyethylene terephthalate, polyethylene naphthalate, polysulfone, and mixtures thereof, but is not limited to these examples.

[0079] For example, aluminum is deposited on a silicon wafer using an e-beam evaporator, and photoresist is patterned on the aluminum using photolithography. The aluminum is then etched using the photoresist as a mask. After the photoresist is removed, the silicon is etched using deep ion reactive etching (DRIE) using the aluminum as a mask. After removing the aluminum, glass is anodically bonded onto the wafer to seal it, completing the microchannel.

[0080] The microchannels have an average diameter of 60 to 150 μm, preferably 80 to 100 μm, but are not limited to this example. If microchannels with an average diameter below this range are used, the emulsion may have an excessively small diameter, which may affect effective drug release and in vivo absorption.

[0081] Furthermore, if the average diameter of the microchannel exceeds the above range, the average size of the produced microparticles will exceed 120 μm, which may increase the sensation of a foreign body and pain when administered as an injection. Furthermore, the larger the diameter of the microchannel, the larger the particle size distribution of the produced particles, making it difficult to produce microparticles with a uniform particle size.

[0082] The average diameter of the microchannel is closely related to the average diameter of the particles, and is also closely related to the flow rate ratio (μl / min) of the oil phase solution and the aqueous phase solution.

[0083] Furthermore, the cross-sectional width (w) and cross-sectional height (d) of the microchannel are closely related to the average diameter (d') of the produced microparticles. The ratio of the cross-sectional width (w) of the microchannel to the average diameter (d') of the microparticles is in the range of 0.7 to 1.3, and the cross-sectional height (d) of the microchannel to the average diameter (d') of the microparticles is in the range of 0.7 to 1.3.

[0084] In other words, once the average diameter (d') of the microparticles to be produced is determined, the width (w) and height (d) of the cross section of the microchannel must be set within the ratio range of 0.7 to 1.3 of d' to produce microparticles of the desired size.

[0085] To produce microparticles using the microchip, an oil phase solution can be injected into the channel through which the oil phase solution flows, and an aqueous phase solution can be injected into the channel through which the aqueous phase solution flows, to form an emulsion at the junction of the two channels.

[0086] When the oil phase solution and the aqueous phase solution are injected into the microchannel, the flow rate ratio of the oil phase solution to the aqueous phase solution may be 1:10 to 1:50, 1:15 to 1:40, 1:15 to 1:30, or 1:15 to 1:25. By adjusting the flow rate ratio of the oil phase solution to the aqueous phase solution as described above, microparticles with a uniform diameter can be produced.

[0087] The emulsion formed at the interface can be obtained using the prepared aqueous phase solution, i.e., a mixture of surfactant and water, which can be injected into a microchannel to form an emulsion and can also be used to prevent the emulsion from clumping when filled into a water tank.

[0088] The emulsion collected in the water tank can be subjected to removal of residual organic solvents. The step of removing residual organic solvents can be carried out by stirring at a certain temperature and stirring speed to evaporate and remove residual organic solvents present inside the emulsion. The stirring conditions are a primary stirring step at 15-20°C for 50-70 minutes, a secondary stirring step at 20-40°C for 50-70 minutes, and a tertiary stirring step at 40-60°C for 1-3 hours.

[0089] The stirring speed is the same for the first to third stirring steps, and is 300 to 500 rpm, and may be 400 rpm.

[0090] As described above, the temperature condition is gradually increased as the stirring process progresses, and the evaporation rate of the organic solvent present in the emulsion can be controlled by increasing the temperature stepwise.

[0091] The temperature of the oil phase solution and the aqueous phase solution when they flow through the microchannel is also 5 to 20°C, preferably 10°C. That is, after they flow through the microchannel and form an intersection to produce an emulsion, a low temperature of 5 to 20°C is maintained until the collected emulsion is subjected to primary stirring. Maintaining a low temperature during the emulsion production process is essential to producing and maintaining spherical particles. In other words, if the temperature is not low, it becomes difficult to produce particles with a consistent spherical shape.

[0092] Thereafter, in the secondary stirring process, the temperature is gradually increased and the stirring time is increased, so that the organic solvent present in the interior of the emulsion gradually migrates to the surface, where it evaporates, thereby minimizing the effect on the emulsion properties. That is, if the organic solvent evaporates too quickly, the surface of the final microparticles may become uneven and pores may form due to the evaporation of the organic solvent. To prevent this problem, the temperature condition is gradually increased and the stirring time is also increased, as described above, to control the evaporation rate of the organic solvent, and the surface properties of the produced microparticles can be controlled by controlling the evaporation rate of the organic solvent.

[0093] In the tertiary stirring step, after the organic solvent in the emulsion is extracted as an external aqueous phase, the external aqueous phase is heated to a temperature close to the boiling point of the organic solvent and stirred, thereby removing the saturated organic solvent from the aqueous phase and facilitating the removal of the residual organic solvent in the emulsion.

[0094] Finally, in the step of washing and drying the microparticles from which the residual organic solvent has been removed, the microparticles from which all the organic solvent on the surface has been removed by stirring are washed several times with sterilized and filtered purified water to remove any surfactant remaining on the microparticles, and then freeze-dried.

[0095] The final microparticles are spherical microparticles made of biodegradable polymers with CBD uniformly distributed within them, and can contain CBD and biodegradable polymers in a weight ratio of 1:3 to 1:10.

[0096] As explained above, the final microparticles contain a uniform distribution of butylhydroxytoluene (BHT) in addition to CBD. When the microparticles come into contact with oxygen in the air, BHT is preferentially oxidized, preventing the oxidation of CBD.

[0097] The weight ratio of CBD and biodegradable polymer contained in the microparticles is the same as the weight ratio in the oil phase solution when the emulsion is produced. This is done by passing the emulsion through a microchannel and then removing all of the organic solvent in the emulsion, allowing microparticles containing CBD and biodegradable polymer in the same weight ratio as in the oil phase solution to be produced.

[0098] The microparticles may have an average diameter of 30 to 70 μm, 30 to 65 μm, or 30 to 60 μm. The standard deviation of the average diameter may be 1 to 30 μm, 1 to 20 μm, 1 to 10 μm, or 1 to 7 μm. It has been confirmed that uniform particles can be produced within this diameter range. When used as a sustained-release injection, the uniform particles can reduce the sensation of foreign matter, improve administration convenience, and prevent initial excessive release upon infusion, resulting in a sustained CBD release effect.

[0099] Manufacturing example Microparticle production 1) Preparation of oil phase solution Cannabidiol, biodegradable polymers (lactide-glycolide copolymer, lactide copolymer alone or a mixture thereof), and butylhydroxytoluene (BHT) were dissolved in methylene chloride to prepare an oil phase solution. The biodegradable polymer in the oil phase solution was contained at a ratio of 15 wt%, and the weight ratio of cannabidiol to biodegradable polymer was 1:3 to 1:10.

[0100] 2) Preparation of aqueous solution Polyvinyl alcohol was dissolved in water to prepare an aqueous phase solution, and the aqueous phase solution contained 0.25% by weight of polyvinyl alcohol.

[0101] 3) Microparticle production The oil and aqueous solutions were injected into a microchannel formed on a silicon wafer to produce microparticles. The oil / aqueous flow ratio was 1:20, and the temperature was maintained at 10.0°C. The produced microparticles were collected in a water bath containing the aqueous solution and stirred at 400 rpm at 10.0°C for 1 hour, 30.0°C for 1 hour, and 45.0°C for 2 hours.

[0102] 4) Cleaning and harvesting After stirring, the microparticles were washed with sterilized and filtered purified water, and then freeze-dried to obtain a powder.

[0103] Microspheres were prepared using the ingredients and amounts shown in Table 1 below by the method described below.

[0104] [Table 1]

[0105] Experimental Example 1 CBD release experiment 1) Preparation of standard solution Approximately 15 mg of cannabidiol standard was taken and placed in a 100 mL flask. Approximately 50 mL of diluent (acetonitrile) was added and ultrasonicated for 10 minutes. After sufficient cooling, the mark was aligned with the test solution, and the solution was filtered through a 0.45 μm filter (water-soluble PTFE) and used as the standard solution (concentration: 0.15 mg / mL).

[0106] 2) Preparation of dissolution test solution Tween 20 was added to 1 L of 10 mM PBS buffer (pH 7.4) to give a concentration of 0.05% (w / v), and then sodium azide and sodium ascorbate were added to the mixture to give concentrations of 0.02% (w / v) and 0.0625% (w / v), respectively, to prepare a dissolution test solution.

[0107] 3) Preparation of test solution Each sample was precisely weighed to 15 mg of the main component and placed in an injection vial. 100 mL of dissolution test solution was then added accurately and sealed. The vial was then shaken at 120 rpm at a constant temperature of around 50°C. The injection vial was placed horizontally. 2, 18, and 72 hours after the start of dissolution, the injection vial containing the sample was removed and left for 3 minutes to allow the sample to sink in the test solution. 1 mL of test solution was then accurately taken using a syringe, centrifuged at 3000 rpm for 3 minutes, and the supernatant was used as the test solution.

[0108] 4) HPLC conditions -Detector: UV (220 nm) -Column: ODS column (4.6*150mm, 5μm) -Flow rate: 1.0mL / min Mobile phase: methanol: purified water = 85:15 (Isocratic method) -Calculation formula: main peak area of ​​test solution * amount of standard taken * purity of standard (%) * dilution ratio / peak area of ​​main component in standard solution * equivalent amount of cannabidiol in test solution (mg)

[0109] The results of the CBD elution experiment conducted under the above experimental conditions are shown in Figure 1 and Table 2.

[0110] [Table 2]

[0111] According to the experimental results, Comparative Example 1 released 44.5% of CBD after 2 hours, 82.6% after 18 hours, and 97.9% after 72 hours, almost completing the release. This indicates that the initial CBD release was too large to achieve a sustained CBD release effect.

[0112] In addition, in the case of Comparative Example 2, although 47.9% CBD was released after 72 hours, demonstrating the effect of long-term sustained release, only 3% of CBD was released after 2 hours, meaning that the initial CBD release amount was too low, resulting in an insufficient effect of CBD in treating and improving inflammatory diseases.

[0113] In contrast, in Examples 1 to 5, an appropriate level of CBD release effect was observed after 2 hours, and release was not completely completed even after 72 hours, demonstrating a long-lasting drug release effect.

[0114] Experimental Example 2 Rat pharmacokinetic study The experimental conditions for conducting the rat pharmacokinetics experiment are as follows.

[0115] [Table 3]

[0116] CBD Isolate Solution was used as a control group. Six-week-old male SD rats were purchased from KOATECH and allowed to adapt for one week before the study began. They were fed standard laboratory animal feed (Orient) and allowed free access to water and food.

[0117] General symptoms During the experiment, all animals were observed twice daily (morning and afternoon) for changes in general symptoms, and their body weights were measured at the time of introduction and at the time of separation from the groups.

[0118] Blood sampling After acclimation, 500–1000 μL of blood was collected from the jugular vein of rats at 0 time before SC administration of the test substance and at 4 hours, 8 hours, 24 hours, 3 days, 5 days, 1 week, 2 weeks, 4 weeks, 6 weeks, 8 weeks, and 12 weeks after administration of the test substance (14 time points in total). The blood was then immediately centrifuged at 1000 g for 10 minutes to separate the serum, which was then frozen and stored at −70°C.

[0119] The pK measurement results for the microparticles of Examples 1 to 5 obtained through the above experiment are shown in Table 4 below and FIG.

[0120] [Table 4]

[0121] The experimental results confirmed that the blood CBD concentration was maintained for at least one month in Examples 1 to 5. That is, in Example 1, the concentration was 0.036 μg / mL at 4 weeks, and in Example 4, it was 0.782 μg / mL.

[0122] Furthermore, in the cases of Examples 2 to 5, the blood CBD concentration could be confirmed even after 7 weeks, confirming the sustained CBD release effect.

[0123] Experimental Example 3 Treatment experiments for osteoarthritis (OA) After completing the acclimation, the rats were separated into groups, and the hair around the left knee joint was thoroughly removed. Then, MIA (Monosodium iodoacetate, Sigma, USA), an osteoarthritis inducer, was diluted with 0.9% sterile saline to a concentration of 60 mg / mL and then inoculated into the rats using a BD Ultra-Fine TM 50 μl of each was administered into the joint cavity using an insulin syringe. The same amount of 0.9% sterile saline alone was administered to the right knee joint. Two weeks after MIA administration, the test substances shown in Table 5 below were administered into the joint cavity, and the therapeutic efficacy was evaluated.

[0124] [Table 5]

[0125] Administration method CBD solution and Examples 2 to 4 groups were administered intra-articularly in the left knee 14 days after MIA administration, while the same amount of 0.9% sterile saline alone was administered to the right knee joint. The same amount of 0.9% saline was also administered to the normal control and positive control groups.

[0126] Dose level selection -CBD solution: Based on existing literature, the effective concentration in the MIA-OA model was selected as 300 μg / joint. Examples 2-3: Maximum feasible dose level (1-2 mg / joint) considering the volume of microspheres and the amount that can be administered into the rat joint cavity (30 ul)

[0127] Weight measurement results The results of body weight measurements taken during the test period are shown in Figure 3. The positive control showed the lowest weight gain, while the CBD solution and Examples 2 to 4 groups showed a tendency for increased weight gain compared to the positive control. The groups administered Examples 3 and 4 showed a statistically significant increase in weight gain compared to the positive control. When OA was induced, a decrease in food intake due to pain and gait disturbance was generally observed, which tended to result in a decrease in body weight. However, when CBD was administered, pain was reduced and food intake activity improved, resulting in an increase in weight gain compared to the positive control. This tendency was particularly pronounced in Examples 3 and 4.

[0128] Measurement of lower limb weight bearing Lower limb weight bearing was measured before MIA administration (day 0), and 6 and 13 days after MIA administration (before test drug administration). The right and left paws were measured using an incapacitance tester (Ugo Basile, Italy) at 2 hours, 4 hours, 3 days, 6 days, 10 days, 13 days, 20 days, and 27 days after test drug administration. The weights (g) of both paws were measured without the rat's abdomen touching the device's sensor. The results were analyzed as the ratio (% Left / Right) of the weights measured for the left and right paws. The weight (g) of both lower limbs was measured on each measurement day. When arthritis was induced, the weight bearing of the induced side (left) decreased. The weight bearing value was calculated using the following formula: Weight bearing value = normal leg weight (right) / arthritis-induced leg weight (left) Relative pain ratio (%) = (average weight load of each group / average weight load of normal group) x 100

[0129] The test results are shown in Figure 4.

[0130] The positive control group showed a significant change in weight bearing compared to the normal control group, confirming the induction of arthritis. Two hours after administration, both the CBD solution and Examples 2 to 4 groups showed a significant improvement in weight bearing compared to the positive control (PC) group.

[0131] The CBD solution group showed no difference compared to the PC control group two hours after administration. The group administered in Example 4 showed a tendency for weight bearing to improve compared to the PC control group after 14 days of administration, and statistically significant improvements were observed compared to the control group on days 14 and 28. The group administered in Example 3 showed a tendency for pain to decrease compared to the PC control group on days 14 and 21 of administration, with significance confirmed on day 14.

[0132] Paw withdrawal threshold test The avoidance response test was performed before MIA administration (day 0), and on days 7 and 14 after MIA administration (before test drug administration). The paw avoidance response was assessed after mechanical stimulation using an electronic von-Frey aesthesiometer (IITC Life Science, USA) at 2 hours, 4 hours, 4 days, 7 days, 11 days, 14 days, 21 days, and 28 days after test drug administration. To measure the paw avoidance response, rats were placed in a transparent acrylic tube on a wire mesh and allowed to adapt to the new environment for approximately 20 minutes. An electronic von-Frey filament was applied perpendicular to the sole of the paw to measure the threshold (g force) at which a sudden avoidance response occurred. The results were analyzed as the ratio (left / right) of g forces measured on the left and right paws.

[0133] Paw withdrawal threshold ratio = Left threshold (induced side) / Right threshold (normal side). When arthritis is alleviated, the left-right ratio changes to be equal (ratio 1).

[0134] The test results are shown in Figures 5 to 12.

[0135] The positive control (PC) group showed a significantly increased threshold compared to the normal control group. At 2 hours after administration, the CBD solution and Examples 2-4 administration groups all showed significant improvement compared to the PC control group. Specifically, the CBD solution administration group showed a tendency for a decrease compared to the PC control group at 2 hours after administration, and thereafter showed no difference compared to the control group. The Example 2 administration group showed a sustained trend of improvement even after 4 days of administration, with statistically significant improvement on days 4, 21, and 28. The Example 4 administration group showed a sustained trend of improvement even after 4 days of administration, with statistically significant improvement on days 4 and 11. Finally, the Example 3 administration group showed a sustained trend of improvement even after 4 days of administration, with statistically significant improvement on days 11, 14, and 21.

[0136] The results of the lower limb weight bearing test and paw withdrawal threshold test showed that the CBD solution group showed an early effect compared to the PC control group, but thereafter no difference was observed between the group and the PC control group. In contrast, Examples 2 to 4 showed a long-lasting therapeutic effect compared to the PC control group, demonstrating through experiments that not only did treatment and improvement effects appear in the osteoarthritis model, but also that a long-lasting therapeutic effect was observed.

[0137] Experimental Example 4 Stability evaluation Microparticles were produced in the same manner as in Example 1, except that they had the same composition as in Example 1 and did not contain BHT.

[0138] Approximately 100 mg of the microparticles were weighed into a 5 mL glass vial and placed in a capped or uncapped (closed / open) stability chamber. For stability evaluation, the vials were stored under long-term conditions (temperature: 25 ± 2°C, relative humidity: 60 ± 5%), and daily changes in properties were observed to confirm the presence or absence of yellowing. Meanwhile, the initial samples and samples stored for 6 days underwent encapsulation tests to confirm the presence or absence of changes in content.

[0139] The experimental results are shown in Figure 13.

[0140] It was confirmed that no color change occurred immediately after the microparticles were produced, and after 6 days, the presence or absence of yellowing was checked. It was confirmed that the color changed to yellow when BHT was not contained, regardless of whether the glass vial was capped or not.

[0141] In contrast, when 1% by weight of BHT was contained as in Example 1, the color did not change and it was confirmed that the product exhibited excellent stability.

[0142] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Industrial Applicability]

[0143] The present invention relates to a sustained-release injectable composition for treating or preventing inflammatory diseases and a method for preparing the same.

Claims

1. It contains microparticles that release cannabidiol (CBD) for a sustained period of more than one month. The microparticles comprise cannabidiol and a biodegradable polymer. A sustained release injectable composition for the treatment or prevention of inflammatory diseases.

2. The microparticles contain cannabidiol and a biodegradable polymer in a weight ratio of 1:3 to 1:

10. The sustained-release injectable composition for treating or preventing an inflammatory disease according to claim 1.

3. The biodegradable polymer is selected from the group consisting of polylactic acid, polylactide, polylactic-co-glycolic acid, polylactide-co-glycolide (PLGA), polyphosphazene, polyiminocarbonate, polyphosphoester, polyanhydride, polyorthoester, polycaprolactone, polyhydroxyvalerate, polyhydroxybutyrate, polyamino acid, and combinations thereof. The sustained-release injectable composition for treating or preventing an inflammatory disease according to claim 1.

4. The polylactide-co-glycolide has a lactide:glycolide monomer ratio of 40:60 to 90:

10. The sustained-release injectable composition for treating or preventing an inflammatory disease according to claim 3.

5. The inflammatory disease is osteoarthritis. The sustained-release injectable composition for treating or preventing an inflammatory disease according to claim 1.

6. According to the following release test, the microparticles release 35% to 80% of the total CBD weight after 18 hours. The sustained-release injectable composition for treating or preventing inflammatory diseases according to claim 1: [Release test conditions] The dissolution test solution was prepared by mixing 1 L of 10 mM PBS buffer (pH 7.4) with Tween 20 to a concentration of 0.05% (w / v), and then mixing sodium azide and sodium ascorbate to the mixture to a concentration of 0.02% (w / v) and 0.0625% (w / v), respectively. 100 mL of the dissolution test solution was placed in an injection vial, and the microparticles were placed therein, so that the total weight of the CBD in the microparticles was 15 mg. After the injection vial was completely sealed, the test was carried out by maintaining the temperature at 50°C and shaking at a speed of 120 rpm. After 18 hours from the start of dissolution, the injection vial was removed and left for 3 minutes, and then 1 mL of test liquid was accurately taken using a syringe. The test liquid was centrifuged at 3000 rpm for 3 minutes, and the supernatant was used as the test liquid to confirm the release of CBD.

7. Dissolving cannabidiol (CBD) and a biodegradable polymer in an organic solvent to produce an oil phase solution; dissolving a surfactant in water to produce an aqueous phase solution; mixing the oil phase solution and the aqueous phase solution to form an emulsion; A method for preparing a sustained-release injectable composition for treating or preventing inflammatory diseases.

8. obtaining the emulsion in an aqueous phase solution and removing residual solvent; washing and freeze-drying the emulsion from which the residual solvent has been removed to produce microparticles; and mixing the lyophilized microparticles with water for injection. A method for producing the sustained-release injectable composition for treating or preventing inflammatory diseases according to claim 7.

9. The oil phase solution and the aqueous phase solution are injected into each microchannel and allowed to flow, forming an emulsion comprising cannabidiol and a time-release agent at a point where the oil phase solution stream and the aqueous phase solution stream intersect with each other. A method for producing the sustained-release injectable composition for treating or preventing inflammatory diseases according to claim 7.

10. The oil phase solution additionally contains butylhydroxytoluene (BHT), A method for producing the sustained-release injectable composition for treating or preventing inflammatory diseases according to claim 7.

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