Brexpiprazole long-acting microsphere and preparation method thereof

Abstract

The invention belongs to the field of pharmaceutical preparations, and relates to a brexpiprazole long-acting microsphere and a preparation method thereof, and the preparation method comprises the following steps: (1) dissolving brexpiprazole and a degradable polymer in an organic solvent to obtain a drug-containing polymer solution as an oil phase; (2) mixing the drug-containing polymer solution with a polyvinyl alcohol solution through a microfluidic technology to obtain an oil-in-water emulsion; and (3) under a stirring condition, carrying out curing, washing and freeze drying on the oil-in-water type emulsion to obtain the brexpiprazole long-acting microspheres. By adjusting the volatilization stirring time when the O / W primary emulsion is formed, the final in-vitro release rate of the microspheres is adjusted, and the microspheres which are free of burst release and hysteresis period and are slowly released can be screened out. The brexpiprazole long-acting microsphere provided by the invention is simple in preparation process, easy to industrially amplify, high in encapsulation efficiency, large in drug loading capacity, uniform in microsphere particle size distribution, round in shape, good in flowability and good in needle passing property, is easier to inject, has an obvious slow release effect, and can be used for reducing the fluctuation of blood concentration and effectively improving the compliance of psychiatric patients.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical preparations, and in particular relates to a brepazine long-acting microsphere and a preparation method thereof. Background Art

[0002] Brepiprazole is an atypical antipsychotic drug that regulates the monoaminergic neurotransmitter system in the brain. It is a partial agonist of 5-hydroxytryptamine (5-HT1A) and dopamine D2 receptors, an antagonist of 5-hydroxytryptamine (5-HT2A) receptors and dopamine α1 / 2 receptors, and has a wide range of binding affinity for other central monoaminergic receptor subtypes. Its structure is shown in the following formula. Compared with typical antipsychotic drugs, brexpiprazole has reduced extrapyramidal reactions. Compared with the atypical antipsychotic drug aripiprazole, brexpiprazole has increased affinity for 5-HT receptors, reduced activity on D2 receptors, better tolerance, and a lower incidence of akathisia. In clinical practice, it has a better trend in the efficacy of negative symptoms and cognitive function in schizophrenia, and has a faster onset of effect when used as an adjuvant treatment for depression.

[0003]

[0004] Currently, the only brepazine dosage forms on the market are tablets and orally disintegrating tablets, with a target dose of 2-4 mg once a day. Since its launch, brepazine's global sales have increased year by year. From 2015 to 2020, brepazine's global sales increased from US$51 million to US$1.374 billion. However, due to the particularity of mental illness and the relatively long treatment process, patients usually have poor compliance, which makes it difficult to administer the drug regularly, reducing the therapeutic effect. At the same time, the incidence of brepazine tablets in elderly patients with Alzheimer's disease-related cerebrovascular adverse reactions (such as stroke, transient ischemic attack) increases, which may be related to the fact that ordinary oral rapid-release preparations are easy to reach higher required concentrations and blood drug concentrations fluctuate greatly. Therefore, in order to improve patient compliance, reduce side effects, and expand the scope of application for patients, it is of great significance to develop brepazine long-acting microspheres.

[0005] Patent WO 2023036003 A1 discloses a long-acting preparation of brepazine for injection and its preparation method, specifically a microcrystalline injection. The drug crystals are dispersed in the form of a micron-level suspension. The particle size distribution of this dosage form is relatively wide, and the uneven particle size can easily lead to large fluctuations in blood drug concentration, making it difficult to maintain a smooth blood drug concentration. At the same time, the preparation process of this patent is complicated, making it difficult to achieve industrial scale-up production.

[0006] Patent CN 116531379 A discloses a sustained-release composition of brepirazole and its preparation method and application. Dichloromethane is used as an organic solvent, polylactic acid, polylactic acid-glycolic acid copolymer, and polycaprolactone are mixed in a certain proportion as a carrier, and the brepirazole sustained-release composition is prepared by an emulsified solvent volatilization method. The dichloromethane solvent used in its prescription is highly toxic to the human body, and the solubility of brepirazole in dichloromethane is very small. The oil phase cannot achieve the preparation of high-drug-loaded microspheres using dichloromethane as a solvent. Its carrier component polycaprolactone has a collagen stimulating effect, which can cause local tissue induration and has uncontrollable side effects for patients with immune diseases.

[0007] Patent CN 118477048 A discloses a brepazine sustained-release microsphere and its preparation method. Its emulsification volatilization time is more than 4 hours, and volatilization and curing need to be controlled at different temperatures. The process is relatively complicated and the production efficiency is not high. The preparation process adopts a stator-rotor shear emulsification method, which is limited by batch differences during the scale-up process. Different batches lead to different shear mixer parameters. When the scale-up production is carried out, it is easy to have problems such as large quantity and uneven stirring / shearing, and the encapsulation rate and the output of microspheres will also be greatly reduced. Therefore, it is extremely challenging to scale up the process. Summary of the invention

[0008] To solve the above technical problems, the present invention uses a benzyl alcohol / ethyl acetate system that is safer than dichloromethane as an organic solvent. Polylactic acid and polycaprolactone are not used, and only a safer degradable polymer, polylactic acid-glycolic acid copolymer, is used as a carrier to encapsulate drugs, thereby avoiding certain uncontrollable risk factors. At the same time, microfluidic technology is used to prepare a brepazine sustained-release microsphere for injection with uniform particle size, which is easier to inject due to its rounded shape, good fluidity, and good needle-passing property, and the preparation method is simple, which significantly improves the encapsulation rate and drug loading of the traditional method. More importantly, the present invention can adjust the release rate of the microspheres by controlling the time of stirring and volatilization, and obtains microspheres with no burst release, no hysteresis period, and slow release for two months or more.

[0009] The first object of the present invention is to provide a method for preparing brepazine long-acting microspheres, comprising the following steps:

[0010] Step (1): dissolving brepazole and a degradable polymer in an organic solvent at a mass ratio of 1:1 to 1:10 to obtain a drug-containing polymer solution as an oil phase;

[0011] Step (2): dissolving polyvinyl alcohol in water to obtain a first aqueous phase with a concentration of 0.1 to 1.5%, mixing the oil phase in step (1) and the first aqueous phase at a volume ratio of 1:1 to 1:45 by microfluidic technology, with a flow rate ratio of the oil phase to the first aqueous phase of 1:1 to 1:45, and volatilizing the organic solvent after obtaining colostrum, controlling the volatilization ratio to 0-20%, to obtain an oil-in-water emulsion;

[0012] Step (3): adding the oil-in-water emulsion of step (2) to the second aqueous phase as a solidification phase for solidification, wherein the volume of the solidification phase is 0.05 to 1.0 L / g microspheres, and the solidification time is 2 to 6 hours. After the solidification is completed, washing and drying are performed to obtain the brepazine long-acting microspheres;

[0013] In step (1), the degradable polymer is polylactic acid-co-glycolic acid or polylactic acid;

[0014] In step (1), the organic solvent forming the oil phase is a benzyl alcohol-ethyl acetate mixed solvent system.

[0015] As a further optimization scheme, in step (1), brepazole is dissolved in benzyl alcohol to obtain a brepazole solution; polylactic acid-glycolic acid copolymer or polylactic acid is dissolved in ethyl acetate to obtain a polymer solution; then the brepazole solution and the polymer solution are mixed with each other and vortex dispersed to obtain the oil phase.

[0016] As a further optimization scheme, in step (1), the mass concentration of the brepazole solution is 2% to 20%; the mass concentration of the degradable polymer solution is 4% to 35%.

[0017] As a further optimization scheme, in step (1), the mixing ratio of the brepazole solution and the polymer solution is controlled so that the mass ratio of brepazole to the degradable polymer is 1:1 to 1:5.

[0018] As a further optimization scheme, in step (2), the concentration of the polyvinyl alcohol solution is 0.1-1%.

[0019] As a further optimization scheme, in step (2), the oil-in-water emulsion is obtained by transporting the oil phase and the first water phase to a microfluidic reactor by a pump for mixing.

[0020] As a further optimization scheme, in step (2), the flow rate ratio of the oil phase and the first aqueous phase in the microfluidic reactor is 1:1 to 1:20.

[0021] As a further optimization scheme, in step (2), the volatilization ratio of the organic solvent in the colostrum is controlled to be 0-15%.

[0022] As a further optimization scheme, in step (3), the volume of the solidified phase is 0.1 to 0.5 L / g microspheres.

[0023] The second object of the present invention is to provide a long-acting brepizole microsphere prepared by the above method. The obtained long-acting brepizole microsphere has high encapsulation efficiency, large drug loading, uniform particle size distribution and rounded shape, good fluidity and needle permeability, and is easier to inject.

[0024] The beneficial effects of the present invention are:

[0025] The preparation method of the present invention can obtain brepazine long-acting sustained-release microspheres with high encapsulation rate, large drug loading, uniform particle size, round shape and excellent needle permeability, and the sustained-release effect is long-lasting and can last up to six months.

[0026] The brepazine sustained-release microspheres prepared by the method of the present invention not only have excellent performance, but also the carrier material is a safer polylactic acid-glycolic acid copolymer, and there is no need to add other polymers such as polycaprolactone and polylactic acid to adjust the ratio, which is safer and more friendly to the body.

[0027] The present invention also found that the release rate of the microspheres can be adjusted by controlling the volatilization ratio of the organic solvent, thereby obtaining brepazine microspheres with no burst release, no release hysteresis period, and an ideal release rate, without reducing the encapsulation rate and drug loading of the microspheres. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein:

[0029] Figure 1 This is a scanning electron microscope image of the sustained-release microspheres of Example 1 of the present invention.

[0030] Figure 2 This is a scanning electron microscope image of the sustained-release microspheres of Example 4 of the present invention.

[0031] Figure 3 This is a scanning electron microscope image of the sustained-release microspheres of Comparative Example 1 of the present invention.

[0032] Figure 4 This is a scanning electron microscope image of the sustained-release microspheres of Comparative Example 2 of the present invention.

[0033] Figure 5 The in vitro release curves of the sustained-release microspheres of Examples 1-6, 9, 10 of the present invention and Comparative Example 2 are shown. DETAILED DESCRIPTION

[0034] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0035] In the present invention, unless otherwise specified, the raw materials used are existing products, and the specific preparation operations and performance tests are conventional techniques. For example, stirring is a conventional technique, and the organic solvent is removed by conventional stirring volatilization method in a fume hood.

[0036] In the present invention, unless otherwise specified, the freeze drying machine model used for freeze drying is FDU-2110.

[0037] Example 1

[0038] 210 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 420 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 90 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 7 mL of the oil phase and 35 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0039] Example 2

[0040] 210 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 420 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 7 mL of the oil phase and 35 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0041] Example 3

[0042] 210 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 420 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 7 mL of the oil phase and 35 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 9.5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0043] Example 4

[0044] 210 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 420 mg of polylactic acid-co-glycolic acid (ester-terminated lactide to glycolide molar ratio = 75:25, Mw = 130 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 7 mL of the oil phase and 35 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The resulting emulsion was not stirred and volatilized, but directly poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0045] Example 5

[0046] 200 mg of brepazole was weighed and dissolved in 4 ml of benzyl alcohol to obtain a brepazole solution; 400 mg of polylactic acid-co-glycolic acid (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 6 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 10 mL of the oil phase and 50 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 2% of the weight of the emulsion, and then the dispersed system was poured into 160 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0047] Example 6

[0048] 160 mg of brepazole was weighed and dissolved in 4 ml of benzyl alcohol to obtain a brepazole solution; 480 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 8 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 12 mL of the oil phase and 60 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 225 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0049] Example 7

[0050] 120 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 240 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 3 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 6 mL of the oil phase and 30 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 90 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0051] Example 8

[0052] 120 mg of brepazole was weighed and dissolved in 2 ml of benzyl alcohol to obtain a brepazole solution; 360 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 12 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 6 mL of the oil phase and 30 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 12 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 90 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0053] Example 9

[0054] 480 mg of brepazole was weighed and dissolved in 4 ml of benzyl alcohol to obtain a brepazole solution; 480 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 90 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 8 mL of the oil phase and 40 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 135 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0055] Example 10

[0056] 160 mg of brepazole was weighed and dissolved in 4 ml of benzyl alcohol to obtain a brepazole solution; 480 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 12 kDa) was weighed and dissolved in 8 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 12 mL of the oil phase and 60 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 8.5% of the weight of the emulsion, and then the dispersed system was poured into 225 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0057] Embodiment 11

[0058] 4 g of brepazole was weighed and dissolved in 20 g of benzyl alcohol to obtain a brepazole solution; 8 g of polylactic acid was weighed and dissolved in 16 g of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed and vortex dispersed to serve as the oil phase. The oil phase and a 1% polyvinyl alcohol aqueous solution were transported to a microreactor at a flow rate ratio of 1:5 by a horizontal flow pump, and the obtained emulsion was poured into 6000 mL of ultrapure water, solidified for 6 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0059] Example 12

[0060] 4 g of brepazole was weighed and dissolved in 16 g of benzyl alcohol to obtain a brepazole solution; 20 g of polylactic acid-glycolic acid copolymer was weighed and dissolved in 37 g of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. The oil phase and a 0.1% polyvinyl alcohol aqueous solution were transported to a microreactor at a flow rate ratio of 1:20 by a horizontal flow pump, and the obtained emulsion was stirred to volatilize 15% of the weight of the emulsion, and then the dispersed system was poured into 2400 mL of ultrapure water, solidified for 6 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0061] Comparative Example 1

[0062] 120 mg of brepazole was weighed and dissolved in 2 mL of benzyl alcohol to obtain a brepazole solution; 240 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 90 kDa) was dissolved in 2 mL of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortexed to disperse as the oil phase. The oil phase was then added dropwise to 20 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution, and the obtained emulsion was stirred to evaporate 5% of the weight of the emulsion, and then the dispersed system was poured into 120 mL of ultrapure water, stirred for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0063] Comparative Example 2

[0064] 40 mg of brepazole was weighed and dissolved in 1 mL of benzyl alcohol to obtain a brepazole solution; 120 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 12 kDa) was dissolved in 2 mL of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortexed to disperse as the oil phase. The oil phase was then added dropwise to 15 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution, and the obtained emulsion was stirred to evaporate 5% of the weight of the emulsion, and then the dispersed system was poured into 90 mL of ultrapure water, stirred for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0065] Comparative Example 3

[0066] 40 mg of brepazole was weighed and dissolved in 1 mL of benzyl alcohol to obtain a brepazole solution; 120 mg of polylactic acid-glycolic acid copolymer (molar ratio of carboxyl-terminated lactide to glycolide = 75:25, Mw = 12 kDa) was dissolved in 2 mL of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortexed to disperse as the oil phase. The oil phase was then added dropwise to 15 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution, and the obtained emulsion was stirred to evaporate 5% of the weight of the emulsion, and then the dispersed system was poured into 90 mL of ultrapure water, stirred for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0067] Comparative Example 4

[0068] 40 mg of brepazole was weighed and dissolved in 1 mL of benzyl alcohol to obtain a brepazole solution; 120 mg of polylactic acid-glycolic acid copolymer (molar ratio of carboxyl-terminated lactide to glycolide = 50:50, Mw = 12 kDa) was dissolved in 2 mL of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortexed to disperse as the oil phase. The oil phase was then added dropwise to 15 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution, and the obtained emulsion was stirred to evaporate 5% of the weight of the emulsion, and then the dispersed system was poured into 90 mL of ultrapure water, stirred for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0069] Comparative Example 5

[0070] 120 mg of brepazole was weighed and dissolved in 1.3 mL of benzyl alcohol to obtain a brepazole solution; 120 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 90 kDa) was dissolved in 0.7 mL of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortexed to disperse as the oil phase. The oil phase was then added dropwise to 10 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution, and the obtained emulsion was stirred to evaporate 5% of the weight of the emulsion, and then the dispersed system was poured into 60 mL of ultrapure water, stirred for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0071] Comparative Example 6

[0072] 120 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 360 mg of polylactic acid-glycolic acid copolymer (molar ratio of carboxyl-terminated lactide to glycolide = 50:50, Mw = 12 kDa) was weighed and dissolved in 6 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 9 mL of the oil phase and 45 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0073] Comparative Example 7

[0074] 120 mg of brepazole was weighed and dissolved in 3 ml of benzyl alcohol to obtain a brepazole solution; 360 mg of polylactic acid-co-glycolic acid (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 12 kDa) was weighed and dissolved in 6 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 9 mL of the oil phase and 27 mL of a 0.005 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:3 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0075] Comparative Example 8

[0076] 480 mg of brepazole was weighed and dissolved in 4 ml of benzyl alcohol to obtain a brepazole solution; 480 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 90 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 8 mL of the oil phase and 40 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 135 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0077] Comparative Example 9

[0078] 200 mg of brepazole was weighed and dissolved in 4 ml of benzyl alcohol to obtain a brepazole solution; 400 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 12 kDa) was weighed and dissolved in 6 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 10 mL of the oil phase and 50 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0079] Comparative Example 10

[0080] 210 mg of brepazole was weighed and dissolved in 3 ml of dimethyl sulfoxide to obtain a brepazole solution; 420 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 7 mL of the oil phase and 35 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0081] Comparative Example 11

[0082] 210 mg of brepazole was weighed and dissolved in 3 ml of dichloromethane to obtain a brepazole solution; 420 mg of polylactic acid-glycolic acid copolymer (molar ratio of ester-terminated lactide to glycolide = 75:25, Mw = 130 kDa) was weighed and dissolved in 4 ml of ethyl acetate to obtain a polymer solution; the brepazole solution and the polymer solution were mixed with each other and vortex dispersed as the oil phase. 7 mL of the oil phase and 35 mL of a 0.01 g / mL polyvinyl alcohol aqueous solution were transported to the microreactor by a horizontal flow pump at a flow rate ratio of 1:5 and a total flow rate of 20 mL / min. The obtained emulsion was stirred to volatilize 5% of the weight of the emulsion, and then the dispersed system was poured into 125 mL of ultrapure water, solidified for 2 hours, filtered, washed with water 3 times, and freeze-dried to obtain brepazole microsphere powder.

[0083] Test Example 1 Microsphere drug loading and encapsulation efficiency

[0084] Octadecylsilane bonded silica gel was used as a filler; 0.15% phosphoric acid: acetonitrile (68:32) was used as the mobile phase, and the detection wavelength was 215nm; 10 mg of the brepazole microspheres prepared in Examples 1-10 and Comparative Examples 1-11 were weighed respectively, dimethyl sulfoxide was added to dissolve the microspheres, and then 0.15% phosphoric acid solution was added to make the volume to 100 mL, shaken well, and part of the solution was centrifuged at 12500 rpm, and the supernatant was taken for HPLC analysis to measure the total drug concentration. Weigh 10 mg of microspheres, add 0.15% phosphoric acid solution to make the volume to 10 mL, take the supernatant, and perform HPLC analysis to measure the free drug concentration. The total drug amount minus the free drug amount is the encapsulated drug amount; the calculation formula for drug loading and encapsulation efficiency is as follows:

[0085]

[0086] Table 1 Drug loading and encapsulation efficiency of microspheres in different embodiments and comparative examples

[0087] Sample Theoretical drug loading (%) Drug loading (%) Encapsulation rate (%) Example 1 33.33 31.93 99.81 Example 2 33.33 30.15 99.96 Example 3 33.33 34.22 98.22 Example 4 33.33 30.71 99.96 Example 5 33.33 32.63 99.92 Example 6 25.00 23.70 99.94 Example 7 33.33 32.21 99.24 Example 8 25.00 24.53 99.65 Example 9 50.00 42.19 98.44 Example 10 25.00 22.73 98.74 Embodiment 11 33.33 30.33 99.78 Example 12 16.67 16.15 99.86 Comparative Example 1 33.33 25.35 98.75 Comparative Example 2 25.00 18.01 99.57 Comparative Example 3 25.00 19.07 98.14 Comparative Example 4 25.00 14.36 55.94 Comparative Example 5 25.00 17.69 89.09 Comparative Example 6 25.00 16.93 82.34 Comparative Example 7 25.00 21.50 84.71 Comparative Example 8 25.00 13.00 75.49 Comparative Example 9 25.00 5.01 9.64 Comparative Example 10 33.33 15.83 44.35 Comparative Example 11 33.33 / /

[0088] In comparative examples 1-5, the present invention adopts the method of adding the oil phase dropwise into the aqueous phase and stirring to prepare the brexpiprazole microspheres. It is found that for the microspheres prepared in this way, most samples can achieve an encapsulation rate of more than 95%, but there are still large differences overall; the process loss of the drug is large, and the drug loading is much smaller than the theoretical drug loading. Although attempts have been made to change different factors, such as using different amounts of raw materials, changing the molecular weight of the polymer, adjusting the proportion of the solvent, adjusting different polymer end-capping types, etc., these attempts have failed to completely improve the problems in encapsulation rate and drug loading to achieve the desired effect. In addition, the mass transfer process of this process is greatly affected by volume. Once the production is scaled up, the process parameters need to be readjusted, and the scaled-up production is difficult.

[0089] In Examples 1-10 and Comparative Examples 6-11, the present invention uses microfluidics to input the two-phase solution into a microfluidic device to prepare brexpiprazole microspheres, and attempts to explore a large number of process conditions such as flow rate ratio and total flow rate, stirring volatilization time, polymer and ratio, solvent system, and curing conditions, and the following findings are made.

[0090] As shown in Table 1, Examples 2-4 change the degree of stirring volatility, which has little effect on the microsphere encapsulation efficiency and drug loading, indicating that the process has good stability. The molecular weights of the polylactic acid-glycolic acid copolymers used in Examples 1, 2, and 8 are different, which have little effect on the microsphere encapsulation efficiency and drug loading, indicating that the change in PLGA molecular weight does not constitute a limiting factor within a certain range. However, when PLGA was changed to carboxyl end-capping and the molar ratio of lactide to glycolide was 50:50 in Comparative Example 6, it was observed that the encapsulation efficiency and drug loading decreased significantly, indicating that the end-capping group of PLGA has an important influence on the preparation of brepazole microspheres. In contrast, the scheme of selecting PLGA with an ester end-capping and a molar ratio of lactide to glycolide of 75:25 is more ideal. In addition, the use of dimethyl sulfoxide as an organic solvent in Comparative Example 10 resulted in a lower encapsulation efficiency, while in Comparative Example 11, due to the limited solubility of brepazole in dichloromethane, a large amount of drug leakage occurred during the preparation process, and the microspheres collected were very few, so that effective testing could not be performed. In contrast, the benzyl alcohol / ethyl acetate solvent system helped to improve the solubility of brepazole and achieve higher encapsulation efficiency and drug loading.

[0091] As shown in Table 1, from the perspective of encapsulation rate and drug loading, the better prescriptions are Examples 1-10, and the prepared microspheres have an encapsulation rate of more than 98%, and the drug loading is close to the theoretical drug loading. Among them, in Example 9, the microspheres with a drug-loading ratio of 1:1 prepared by microfluidic technology can reach a drug loading of 42% and an encapsulation rate of more than 98%. Despite a thorough search of relevant literature, patents and market information, no brepazine microsphere product has been found that can achieve a high drug loading of more than 40% while ensuring such a high encapsulation rate.

[0092] As shown in Table 1, it is also found that the O / W colostrum prepared by microfluidic technology in Example 4 can obtain microspheres with an encapsulation rate of more than 99% without stirring and directly solidifying, and the difference between the drug loading and the theoretical drug loading is not large. This solution is particularly significant in process simplification, greatly speeding up the production progress while ensuring quality, and is particularly suitable for industrial production.

[0093] Test Example 2 Microsphere Particle Size

[0094] Take an appropriate amount of the microspheres prepared in Examples 1-10 and Comparative Examples 1-11, divide them into three parts, disperse them in water respectively, and use BT-2001 laser particle size distribution analyzer to measure the particle size of the microspheres. The results are shown in Table 2.

[0095] Table 2 Microsphere particle size of different embodiments and comparative examples

[0096]

[0097]

[0098] As can be seen from Table 2, in Examples 6, 8, and 10, when the molecular weight of the polylactic acid-glycolic acid copolymer is small, the particle size of the prepared microspheres is also small. Compared with other embodiments, the collection of small-size microspheres requires a smaller screen, which is easy to block the screen, and it is difficult to wash the microspheres, which is not efficient and is not suitable for industrial production. When the molecular weight of the polylactic acid-glycolic acid copolymer is above 90kDa, microspheres with a particle size of 50-80μm can be prepared by a flow control device, with uniform particle size and good needle permeability. In addition, when the drug-loading ratio of the microspheres prepared by the direct dripping preparation process is increased to 1:1 and 1:2 (Comparative Example 1, Comparative Example 9), the particle size is greater than 100μm, which is not suitable for intramuscular injection. Therefore, from the perspective of particle size, Examples 1-5, 7, and 9 are better prescriptions.

[0099] Test Example 3 Determination of microsphere morphology and angle of repose

[0100] Take appropriate amount of microspheres prepared in Examples 1, 4 and Comparative Examples 1, 2, and measure the morphology of the microspheres using a scanning electron microscope. Figure 1-4 .

[0101] Table 3 Determination of the angle of repose of microspheres in different embodiments and comparative examples

[0102] Sample Angle of repose Example 1 37.6° Example 4 38.3° Comparative Example 1 44.9° Comparative Example 2 45.2°

[0103] It can be seen from the results of the repose angle that the brexpiprazole microspheres prepared by microfluidic technology have a smaller repose angle and better fluidity.

[0104] According to the results of scanning electron microscopy and angle of repose, the brexpiprazole microspheres prepared by microfluidic technology are more round, have better fluidity, better needle permeability, and are easier to inject.

[0105] Test Example 4 In vitro release of microspheres

[0106] Weigh 2 g of sodium hydroxide and dissolve it in 500 mL of water, discard 105 mL, add 6.8 g of potassium dihydrogen phosphate and dissolve it in 605 mL of water, and then add 2 g of hexadecyltrimethylammonium bromide to obtain a release medium of PBS solution containing 0.2% hexadecyltrimethylammonium bromide at pH 7.4.

[0107] Weigh 12 mg of the brexpiprazole microspheres prepared in Examples 1-6, 9, 10 and Comparative Example 2 respectively into a 100 mL stoppered conical flask, add 100 mL of 0.2% hexadecyltrimethylammonium bromide PBS solution, put it into a 37°C water bath constant temperature oscillating pot, take 1 mL at different time points of 4h, 1d, 3d, 5d, 7d..., centrifuge (8000rpm, 5min), analyze and take a small part of the supernatant for sampling. After all the old release medium of the remaining microspheres is removed, it is replaced with a fresh release medium, and the sample is continued. The samples are analyzed by high performance liquid chromatography, the cumulative release percentage is calculated, and the release curve of the cumulative release percentage-time is drawn. The results are shown in Figure 5 shown.

[0108] Depend on Figure 5 It can be seen that the brepazine microspheres can achieve a sustained release effect of 2 months or more. Example 1 and Example 9 show that the larger the drug loading, the faster the release. Examples 3, 4, 6, and 9 show that when forming O / W colostrum, the stirring time is different and the release rate is also different, which also shows that the release rate can be adjusted by controlling the volatility of the organic solvent. Moreover, the in vitro release curves of the sustained-release microspheres prepared by the same prescription using the dripping process (Comparative Example 2) and the microfluidic process (Example 6) respectively show that the release is relatively slower with the prescription using the microfluidic process.

[0109] The above embodiments are exemplary, and their purpose is to illustrate the technical concept and features of the present invention so that people familiar with the technology in this field can understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing brepazine long-acting microspheres, characterized in that: The following steps are involved: Step (1): dissolving brepazole and a degradable polymer in an organic solvent at a mass ratio of 1:1 to 1:10 to obtain a drug-containing polymer solution as an oil phase; Step (2): dissolving polyvinyl alcohol in water to obtain a first aqueous phase with a concentration of 0.1-1.5%, mixing the oil phase in step (1) and the first aqueous phase at a volume ratio of 1:1-1:45 by microfluidic technology, with the flow rate ratio of the oil phase to the first aqueous phase being 1:1-1:45, and volatilizing the organic solvent after obtaining colostrum, controlling the volatilization ratio to be 0-20%, to obtain an oil-in-water emulsion; Step (3): adding the oil-in-water emulsion of step (2) to the second aqueous phase as a solidification phase for solidification, wherein the volume of the solidification phase is 0.05-1.0 L / g microsphere and the solidification time is 2-6 h. After the solidification is completed, washing and drying are performed to obtain the brexpiprazole long-acting microspheres; In step (1), the degradable polymer is polylactic acid-co-glycolic acid or polylactic acid; In step (1), the organic solvent forming the oil phase is a benzyl alcohol-ethyl acetate mixed solvent system.

2. The method for preparing brepazine long-acting microspheres according to claim 1, characterized in that: In step (1), brepazole is dissolved in benzyl alcohol to obtain a brepazole solution; polylactic acid-glycolic acid copolymer or polylactic acid is dissolved in ethyl acetate to obtain a polymer solution; and the brepazole solution and the polymer solution are mixed with each other and vortex dispersed to obtain the oil phase.

3. The method for preparing brepazine long-acting microspheres according to claim 2, characterized in that: In step (1), the mass concentration of the brepazole solution is 2% to 20%; the mass concentration of the degradable polymer solution is 4% to 35%.

4. The method for preparing breprazol long-acting microspheres according to claim 2, characterized in that: In step (1), the mixing ratio of the brepazole solution and the polymer solution is controlled so that the mass ratio of brepazole to the degradable polymer is 1:1 to 1:

5.

5. The method for preparing breprazol long-acting microspheres according to claim 1, characterized in that: In step (2), the concentration of the polyvinyl alcohol solution is 0.1-1%.

6. The method for preparing breprazol long-acting microspheres according to claim 1, characterized in that: In step (2), the oil-in-water emulsion is obtained by transporting the oil phase and the first water phase to a microfluidic reactor by a pump for mixing.

7. The method for preparing breprazol long-acting microspheres according to claim 6, characterized in that: In step (2), the flow rate ratio of the oil phase to the first aqueous phase in the microfluidic reactor is 1:1 to 1:

20.

8. The method for preparing brepazine long-acting microspheres according to claim 1, characterized in that: In step (2), the volatilization ratio of the organic solvent in the colostrum is controlled to be 0-15%.

9. The method for preparing breprazol long-acting microspheres according to claim 1, characterized in that: In step (3), the volume of the solidified phase is 0.1-0.5 L / g microspheres.

10. A long-acting microsphere of brepizole, characterized in that: Prepared according to the method according to any one of claims 1 to 9.

Images