Pirenzepine long-acting controlled release microspheres and a method for preparing the same

Abstract

The application belongs to the field of medicine, and particularly relates to a kind of pirfenidone long-acting controlled-release microspheres and a preparation method thereof.The purpose of the application is to provide a kind of long-acting and accurate controlled-release pirfenidone microspheres, which is prepared by microfluidic method using inner phase solution and outer phase solution.The inner phase solution comprises pirfenidone and its derivatives, PLGA and good solvent of the two;The outer phase solution comprises surfactant, good solvent of the surfactant and inner phase solvent.The pirfenidone long-acting controlled-release microspheres of the application are very uniform by using microfluidic preparation of PLGA microspheres, can smoothly release drug, have high stability, repeatability and regularity, the microfluidic technology for preparing pirfenidone-PLGA sustained-release microspheres proposed in the application is very promising in combination with customization strategy, and the related microsphere product is also beneficial to transformation, and is an effective solution.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of medicine, and particularly relates to a long-acting controlled-release microsphere of perampanel with precise release control and a preparation method thereof. BACKGROUND

[0002] Epilepsy, commonly known as sheep horn wind or sheep epilepsy, is a chronic disease caused by abnormal discharge of neurons in the brain, leading to temporary dysfunction of the brain. The cause is usually not eradicated, and patients face long-term or even lifelong irregular disease attacks, which seriously affect the normal life of patients, and the disease attack will cause irreversible damage to the central nervous system. There are about 60 million epilepsy patients in the world, of which about 9 million are in China. At present, although there are many antiepileptic drugs to choose from, about 30% of patients still have poor treatment effect due to various reasons.

[0003] There are various types of antiepileptic drugs (AEDs). According to the order of drug appearance, they are divided into traditional antiepileptic drugs and new antiepileptic drugs. Antiepileptic drugs applied in clinical practice before the 1980s are traditionally referred to as traditional antiepileptic drugs, including valproic acid, carbamazepine, phenobarbital, etc. Those appearing after the 1980s are referred to as new antiepileptic drugs, including lamotrigine, levetiracetam, oxcarbazepine, topiramate, etc. However, the therapeutic effect of many antiepileptic drugs has not met the increasing demand for refractory epilepsy, and with the increase in the number of drug types and the increase in the dose, the side effects of the drugs are also a problem to be solved.

[0004] Perampanel is a new type of antiepileptic drug developed and marketed by Japan's Eisai, mainly for refractory epilepsy. It inhibits downstream signaling pathways by non-competitively antagonizing AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors to reduce intracellular calcium ion elevation, achieving the effect of treating epilepsy. The original research data shows that perampanel has good antiepileptic effect. At the same time, perampanel has strong AMPA selectivity (IC50 = 93 nM), and even at a concentration as high as 30 μM, it only has a very weak effect on NMPA, so the risk of side effects is weak. The structure of perampanel is as follows:

[0005]

[0006] The dosage form of pirfenidone currently on the market is tablets, and other common dosage forms such as injections under research all have the disadvantages of high frequency and long cycle of drug taking, poor convenience of drug taking, and large fluctuation of blood drug concentration. Therefore, the inventors expect to make pirfenidone into a sustained-release microsphere preparation to avoid these factors and achieve the effect of once injection for 2 weeks to several months of drug taking, and the smooth release of the microsphere with precise control, so that the blood drug concentration of pirfenidone in the body will be much lower than that of repeated high-frequency oral administration, ensuring the efficacy while reducing the risk of side effects. In addition, pirfenidone was listed in the list of Class II psychotropic drugs by NMPA on July 1, 2023, so there is a need for control to prevent abuse (the amount of a single prescription of an ordinary preparation should not exceed 7 days), and the inventors expect the pirfenidone microspheres to have long-acting sustained-release properties and only need a single injection to be effective for several weeks to several months to solve the need to prevent abuse.

[0007] Currently, pirfenidone also has microspheres and other sustained-release dosage forms under research, such as:

[0008] Chinese patent CN117530933A discloses a long-acting sustained-release microsphere of pirfenidone and a preparation method of an injection thereof. It is mainly prepared by a homogeneous emulsification method, using pirfenidone and pirfenidone 3 / 4 hydrate as raw drugs, and PLGA as a carrier material, to obtain sustained-release microspheres, but the encapsulation efficiency is quite different (45.8%-99.8%), the particle size uniformity is poor, that is, the drug quality control is difficult, and it is difficult to realize stable commercial production.

[0009] Under the above technical background, the inventors of the present application expect to provide a new type of pirfenidone long-acting controlled-release microsphere preparation and a preparation method, which has uniform size, stable quality and can accurately control the release rate. SUMMARY

[0010] The first technical problem solved by the present application is to provide a long-acting and precisely controlled-release pirfenidone microsphere.

[0011] The long-acting controlled-release pirfenidone microsphere of the present application is prepared by a microfluidic method using an inner phase solution and an outer phase solution:

[0012] The inner phase solution comprises pirfenidone, PLGA and an inner phase good solvent, and is composed of the following weight ratio:

[0013] The mass fraction of PLGA in the inner phase solution is 2.0-40.0wt%;

[0014] The theoretical drug loading of pirfenidone is 5.0-60.0wt%;

[0015] The inner phase good solvent is the balance;

[0016] The theoretical drug loading of pirfenidone is calculated by the formula: the mass of pirfenidone divided by the sum of the masses of pirfenidone and PLGA.

[0017] The outer phase solution comprises a surfactant and a good solvent of the surfactant, and the inner phase good solvent, and is composed of the following weight ratio:

[0018] The mass fraction of the surfactant in the outer phase solution is 0.1-5.0wt%;

[0019] The outer phase solution is saturated with a small amount of the inner phase good solvent.

[0020] The main solvent of the outer phase solution is a good solvent of the surfactant, which is not miscible with the inner phase good solvent in any ratio.

[0021] The good solvent of the surfactant is the remainder.

[0022] In the above technical solution:

[0023] Further preferably, the inner phase solution comprises pirfenidone, PLGA and good solvents of the two, and is composed of the following weight ratio:

[0024] The mass fraction of PLGA in the inner phase solution is 5.0-25.0wt%;

[0025] The mass fraction of PLGA in the inner phase solution is 5.0-10.0wt%;

[0026] The theoretical drug loading of pirfenidone and its derivatives is 10-40.0wt%;

[0027] The theoretical drug loading of pirfenidone and its derivatives is 10.0-30.0wt%;

[0028] The inner phase good solvent is the remainder.

[0029] Further preferably, the outer phase solution comprises a surfactant and a good solvent of the surfactant, and the inner phase good solvent, and is composed of the following weight ratio:

[0030] The mass fraction of the surfactant in the outer phase solution is 0.5-2.0wt%;

[0031] The outer phase solution is saturated with a small amount of the inner phase good solvent.

[0032] The main solvent of the outer phase solution is a good solvent of the surfactant, which is not miscible with the inner phase good solvent in any ratio.

[0033] The good solvent of the surfactant is the remainder.

[0034] In the inner phase solution, the inner phase good solvent is any one of dichloromethane, ethyl acetate, chloroform, and acetone; preferably, the inner phase good solvent is dichloromethane.

[0035] The surfactant in the external phase solution comprises any one or more of PVA or poloxamer or PVP, preferably PVA.

[0036] The PVA is any one or more of PVA1788, PVA1799, PVA0588. Preferably, the PVA is PVA1788.

[0037] The good solvent of the surfactant in the external phase solution is water or other solvent that is not miscible with the internal phase solvent at any ratio;

[0038] Preferably, the good solvent of the surfactant is water, and the water can be selected from pure water, water for injection, deionized water, and double-distilled water according to the sensitivity of the prescription process to electrolytes in water;

[0039] The internal phase good solvent in the external phase solution is any one of dichloromethane, ethyl acetate, chloroform, and acetone. Preferably, the internal phase good solvent is dichloromethane. The solvent of the internal phase solution used in the external phase solution is consistent with the solvent used in the internal phase solution, and the purpose is to saturate the reagent in the external phase solution and prevent the solvent in the internal phase solution from diffusing to the external phase during shearing.

[0040] In the above technical solution, the PLGA is a polylactic acid-glycolic acid copolymer, wherein the ratio of lactide (LA) to glycolide (GA) is LA:GA=(95:5) to (5:95); further preferably, LA:GA=(75:25) to (25:75); and still further preferably, LA:GA=(75:25) to (50:50). The weight ratio of LA to GA in the PLGA affects the release time of the pirfenidone microspheres and is one of the key factors for achieving a customized release time.

[0041] The main factor affecting the controllable release period of the pirfenidone microspheres is the type of PLGA, and the main influencing factors include the ratio of LA to GA and the molecular weight, etc.

[0042] 1) The ratio of LA to GA in the PLGA significantly affects the release curve slope of the early lag time and the effective release time after the inflection point: the lag time of the PLGA with 50% LA is less than that of the PLGA with 65% LA, which is less than that of the PLGA with 75% LA; the release rate of the PLGA with 50% LA is greater than that of the PLGA with 65% LA, which is greater than that of the PLGA with 75% LA;

[0043] 2) The molecular weight of PLGA is also an important factor in determining the lag time: the greater the molecular weight of PLGA, the greater the lag time. In summary, to solve the initial lag problem, it is preferred to use PLGA with LA:GA=50:50; to ensure long-term release, it is preferred to use PLGA with LA:GA=75:25. By selecting PLGA, the purpose of controllable release time is achieved.

[0044] The pirfenidone microspheres with customizable release time of the application can be further combined with common pharmaceutical excipients or auxiliary ingredients to form a solvent to form an injection preparation.

[0045] The second technical problem solved by the application is to provide a mixed pirfenidone long-acting controlled-release microsphere made of the aforementioned pirfenidone long-acting controlled-release microsphere, which comprises a mixture of at least two pirfenidone long-acting controlled-release microspheres; specifically, pirfenidone long-acting controlled-release microspheres prepared with different PLGA as raw materials.

[0046] Among them, the different PLGA refers to using different weight average molecular weight of PLGA as raw material.

[0047] For example: PLGA with a weight average molecular weight of 13800 Da is used to prepare pirfenidone long-acting controlled-release microspheres A, and PLGA with a weight average molecular weight of 55800 Da is used to prepare pirfenidone long-acting controlled-release microspheres B, and the pirfenidone long-acting controlled-release microspheres A and the pirfenidone long-acting controlled-release microspheres B are mixed in the following weight ratio:

[0048] Pirfenidone long-acting controlled-release microspheres A 3-7 parts, pirfenidone long-acting controlled-release microspheres B 3-7 parts, and the sum of the weights of the two is 10 parts;

[0049] Preferably, pirfenidone long-acting controlled-release microspheres A 3 parts, pirfenidone long-acting controlled-release microspheres B 7 parts;

[0050] Or preferably, pirfenidone long-acting controlled-release microspheres A 5 parts, pirfenidone long-acting controlled-release microspheres B 5 parts;

[0051] Or preferably, pirfenidone long-acting controlled-release microspheres A 4 parts, pirfenidone long-acting controlled-release microspheres B 4 parts.

[0052] The use of mixed pirfenidone long-acting controlled-release microspheres can significantly prolong the release period, which can reach 2 months or even longer.

[0053] The third technical problem solved by the application is to provide a preparation method of the pirfenidone long-acting controlled-release microsphere, which is prepared by microfluidization, specifically by using an internal phase solution and an external phase solution to form stable droplets, then using a receiving liquid to receive, and then drying, washing and freeze-drying to obtain the pirfenidone microspheres of the application. The specific steps are as follows:

[0054] A, according to the inner phase solution, the outer phase solution, each raw material and auxiliary materials are weighed;

[0055] B, preparation of inner phase solution: using inner phase good solvent to dissolve pirfenidone and PLGA, to obtain the inner phase solution;

[0056] C, preparation of outer phase solution: surfactant and good solvent are fully dissolved, then the inner phase good solvent is fully stirred, and the supernatant is taken after standing and layering, to obtain the outer phase solution;

[0057] D, the inner phase solution and the outer phase solution are injected into the microfluidic device, by controlling the flow rate of the inner phase solution and the outer phase solution, the stable droplets are obtained, and the receiving liquid is used to receive the droplets, to obtain the microemulsion;

[0058] E, the microemulsion is dried and washed to obtain the microsphere suspension;

[0059] F, the microsphere suspension obtained in step E is freeze-dried to obtain the microsphere powder.

[0060] In the technical scheme of the above preparation method, the inner phase solution comprises pirfenidone and its derivatives, PLGA and their good solvents, which are composed of the following weight ratio:

[0061] The mass fraction of PLGA in the inner phase solution is 2.0-40.0wt%;

[0062] The mass fraction of PLGA in the inner phase solution is 5.0-10.0wt%;

[0063] The theoretical drug loading of pirfenidone and its derivatives is 5.0-60.0wt%;

[0064] The theoretical drug loading of pirfenidone and its derivatives is 1.0-30.0wt%;

[0065] The inner phase good solvent is the balance;

[0066] The theoretical drug loading of pirfenidone is calculated by the formula: the mass of pirfenidone divided by the sum of the mass of pirfenidone and PLGA.

[0067] In the inner phase solution, the inner phase good solvent is any one of dichloromethane, ethyl acetate, chloroform and acetone. Preferably, the solvent is dichloromethane.

[0068] In the technical scheme of the above preparation method, the outer phase solution comprises surfactant and good solvent of surfactant, and inner phase good solvent, which is composed of the following weight ratio:

[0069] The mass fraction of surfactant in the outer phase solution is 0.1-5.0wt%;

[0070] Preferably, the mass fraction of the surfactant in the external phase solution is 0.5-2.0wt%; a small amount of the good solvent of the internal phase is added to the external phase solution to saturate the external phase solution;

[0071] The main solvent of the external phase solution should not be miscible with the good solvent of the internal phase at any ratio;

[0072] The good solvent of the surfactant is the remaining amount.

[0073] In the external phase solution, the surfactant includes any one or more of PVA or poloxamer or PVP, preferably PVA is used.

[0074] Among them, the PVA is any one or more of PVA1788, PVA1799, and PVA0588. Preferably, the PVA uses PVA1788.

[0075] In the external phase solution, the good solvent of the surfactant uses water or other solvents that are not miscible with the internal phase at any ratio;

[0076] Preferably, the good solvent of the surfactant is water, and according to the sensitivity of the prescription process to electrolytes in water, pure water, water for injection, deionized water, and double-distilled water can be selected.

[0077] In the technical solution of the above preparation method, the good solvent of the surfactant in step C is added to PVA, poloxamer, or PVP at any one under the condition of heating water to 90-98℃ and stirring to obtain an external phase solution.

[0078] Preferably, the good solvent of the surfactant in step C is added to PVA, poloxamer, or PVP at any one under the condition of heating water to 95℃.

[0079] In the technical solution of the above preparation method, the flow rate of the internal phase solution in step D is 5-200μL / min, and the flow rate of the external phase solution is 300-2000μL / min, while the flow rate of the external phase is controlled to be greater than that of the internal phase.

[0080] Preferably, the flow rate of the internal phase solution in step D is 30-110μL / min, and the flow rate of the external phase solution is 450-1200μL / min, while the flow rate of the external phase is controlled to be greater than that of the internal phase.

[0081] Most preferably, the flow rate of the internal phase solution in step D is 30-110μL / min, and the flow rate of the external phase solution is 600-1200μL / min, while the flow rate of the external phase is controlled to be greater than that of the internal phase.

[0082] The receiving liquid has the same concentration of surfactant PVA, poloxamer or PVP as the external phase solution. The reason for this treatment is to ensure that the liquid at the outlet has a similar viscosity to the receiving liquid, so that it can smoothly merge into the receiving liquid, and that droplet size change, solute diffusion and other conditions do not occur.

[0083] In the technical scheme of the above preparation method, the drying in step E is liquid drying. The purpose is to remove dichloromethane in the pirfenidone microemulsion and solidify to obtain pirfenidone microspheres.

[0084] In the technical scheme of the above preparation method, the drying in step E is liquid drying. The purpose is to remove dichloromethane in the pirfenidone microemulsion and solidify to obtain pirfenidone microspheres.

[0085] Preferably, the liquid drying is carried out at 35-40℃ and 150-180rpm for 3-4h.

[0086] Most preferably, the liquid drying in step E is carried out at 40℃ and 150rpm for 4h.

[0087] In the technical scheme of the above preparation method, the washing in step E is to remove residual PVA from the pirfenidone microspheres. Specifically, after the microspheres are dried (liquid drying) in step E, the supernatant is discarded, and the microspheres are resuspended in a suitable amount of pure water. Then, any of the following methods is used for washing:

[0088] 1) The microspheres are filtered using a 400-500 mesh metal screen. The microspheres are repeatedly resuspended in pure water and filtered until the foaming effect of PVA disappears. In the last filtration, the water in the microspheres is completely filtered out, and the microspheres trapped on the screen are taken and resuspended in a certain amount of pure water to obtain the microsphere emulsion.

[0089] Preferably, a 500 mesh metal screen is used. The 400 mesh metal screen has a pore size of 38 microns, and the 500 mesh metal screen has a pore size of 13 microns, which is suitable for filtering large and small particle sizes and removing unstable small particles.

[0090] Preferably, the washing is not less than 5 times, and the volume of each washing is not less than 500mL / 0.5g of microspheres.

[0091] 2) The microsphere sample is centrifuged at 2000rpm-8000rpm for 3-10min, and the supernatant is discarded. The microspheres are repeatedly resuspended in pure water and centrifuged to remove the supernatant until the foaming effect of PVA disappears. After the last centrifugation, the microspheres are resuspended in a certain amount of pure water to obtain the microsphere emulsion.

[0092] Preferably, the microsphere sample is centrifuged at 2000rpm for 3min.

[0093] Preferably, the resuspension and centrifugation steps are not less than 5 times, and the volume of each resuspension is not less than 500mL / 0.5g of microspheres.

[0094] The technical scheme of the preparation method aims to reduce the water content of the microsphere powder as much as possible and improve the stability and shelf life of the microsphere product.

[0095] The freezing drying condition is below -45℃, the vacuum degree is below 15 Pa, and the freezing drying time is 24-96 h. Preferably, the freezing drying time is 48 h.

[0096] The long-acting controlled-release microspheres of pirfenidone prepared by the microfluidic method are very uniform, and in the in vitro release experiment, the microspheres can stably release the drug, preferably a 0-level release curve, with a sustained-release period of at least 4 weeks, 2 months or even longer. Since only a single dose is needed to meet the effective weeks to months, the defects of high frequency and long period of taking medicine, poor drug convenience and large blood drug concentration fluctuation of the existing pirfenidone preparation can be overcome, and the market supervision can be combined to prevent abuse. In summary, the microfluidic technology for preparing pirfenidone-PLGA sustained-release microspheres combined with the customization strategy is very promising, and the related microsphere product is also conducive to transformation, which is an effective solution. BRIEF DESCRIPTION OF DRAWINGS

[0097] Figure 1 It is a scanning electron microscope graph of Example 1.

[0098] Among them, Figure 1 A is a scanning electron microscope graph with magnification of 2000, Figure 1 B is a scanning electron microscope graph with magnification of 3000.

[0099] Figure 2 It is an in vitro drug release curve of Examples 1, 2, 3, 4, 5, 6.

[0100] Figure 3 It is an in vitro drug release curve of Examples 1, 7, 8.

[0101] Figure 4 It is an in vitro drug release curve of Examples 3, 9, 10.

[0102] Figure 5 It is an in vitro drug release curve of Examples 7, 11, 12.

[0103] Figure 6 It is an in vitro drug release curve of Examples 17, 18, 19. DETAILED DESCRIPTION

[0104] The following will be explained and described the schemes of the present application with examples, but not limit the present application. The person skilled in the art will understand that the following examples are only for illustrating the present application, and should not be considered as limiting the scope of the present application. The specific technology or conditions not noted in the examples, according to the technology or conditions described in the literature in the art or according to the product instructions. The reagents or instruments not noted manufacturer, are all conventional products that can be obtained by market.

[0105] The present application provides a kind of customizable sustained-release time pirfenidone microspheres, it is by with pirfenidone and different kinds of polylactic acid-glycolic acid copolymer as internal phase, surfactant (PVA, poloxamer or PVP) aqueous solution as external phase, using microfluidic method preparation and become slow-release microspheres.By controlling the molecular weight of PLGA, the weight ratio of lactide (LA) and glycolide (GA), end group, component ratio and preparation parameters, such as factor, the size, morphology, pore size, internal structure and surface modification of microsphere are accurately controlled, guarantee the morphology, size of microsphere is highly uniform;It can also ensure that the release rate is almost unchanged within the effective release period, no burst release.

[0106] The following English abbreviation and main noun explanation of the present application are as follows:

[0107] 1, polyvinyl alcohol (PVA) is an organic compound, chemical formula is [C2H4O] n , appearance is white flaky, flocculent or powdery solid, odorless. Soluble in water (above 95 DEG C), slightly soluble in dimethyl sulfoxide, insoluble in gasoline, kerosene, vegetable oil, benzene, toluene, dichloroethane, carbon tetrachloride, acetone, ethyl acetate, methanol, ethylene glycol, etc. Polyvinyl alcohol is an important chemical raw material, used to manufacture polyvinyl acetal, gasoline resistant pipe and vinylon, fabric treatment agent, emulsifier, paper coating, adhesive, glue, etc. The physical properties of polyvinyl alcohol are influenced by chemical structure, alcoholysis degree, degree of polymerization. The main structure in polyvinyl alcohol molecule is 1, 3-propanediol, i.e. "head · tail" structure. The degree of polymerization of polyvinyl alcohol is divided into ultrahigh degree of polymerization (molecular weight 250-300 thousand), high degree of polymerization (molecular weight 17-22 million), medium degree of polymerization (molecular weight 12-15 million) and low degree of polymerization (2.5-3.5 million). Alcoholysis degree generally has 78%, 88%, 98% three kinds. The alcoholysis degree of partial alcoholysis is usually 87%-89%, and the alcoholysis degree of complete alcoholysis is 98%-100%. The average degree of polymerization is usually taken as the first hundred or hundred, and the percentage of alcoholysis degree is taken as the second, i.e. PVA (1788) indicates that the degree of polymerization is 1700 and the alcoholysis degree is 88%. PVA1799 indicates that the degree of polymerization is 1700 and the alcoholysis degree is 99%. PVA0588 indicates that the degree of polymerization is 500 and the alcoholysis degree is 88%.

[0108] 2、Poly(lactic-co-glycolic acid) (PLGA) is a kind of degradable functional polymer organic compound, which is randomly polymerized by two monomers, lactic acid and glycolic acid, has good biocompatibility, non-toxicity, good capsule and film forming performance, and is widely used in pharmaceutical, medical engineering material and modern industrial fields. The preparation of PLGA is mostly by ring-opening polymerization. Common ring-opening polymerization is to synthesize two monomers, glycolide (GA) and lactide (LA), by dehydrating and cyclizing glycolic acid and lactic acid respectively, and then polymerizing GA and LA to obtain a random copolymer of PLGA.

[0109] The following is a preparation example of the pirfenidone microspheres of the present application. The pirfenidone microspheres of the present application can also be referred to as pirfenidone-PLGA sustained-release microspheres in the following examples. The prescription table of the examples is shown in Table 1.

[0110] Table 1 Prescription table of examples

[0111]

[0112] Example 1:

[0113] The present embodiment proposes a preparation method of a sustained-release microsphere preparation containing pirfenidone drug, which comprises the following steps:

[0114] (1) 0.111 g of pirfenidone was weighed and added to 8.889 g of dichloromethane, and the drug was fully dissolved by ultrasonic. The above solution was filtered with a needle type nylon filter head for standby.

[0115] (2) 1 g of poly(lactic-co-glycolic acid) (LA:GA=50:50, Mw=13000 Da, carboxyl terminated) was weighed and added to the above solution, and dissolved by ultrasonic to obtain an oil phase solution.

[0116] (3) A 0.5wt% polyvinyl alcohol solution was prepared as an aqueous phase solution.

[0117] (4) The oil phase and the aqueous phase were respectively injected into a microfluidic device by a syringe pump, the flow rate of the oil phase was adjusted to 20 μl / min, and the flow rate of the aqueous phase was adjusted to 600 μl / min. The continuous phase in the microfluidic device sheared the dispersed phase to obtain an oil-in-water emulsion, and the microspheres were collected.

[0118] (5) The collected microspheres were transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15℃ for 1 h, 25℃ for 1 h, and 35℃ for 1 h), and the organic solvent was volatilized.

[0119] (6) After washing, filtering and drying, pirfenidone long-acting sustained-release microspheres were obtained.

[0120] Example 2:

[0121] The embodiment provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, and comprises the following steps:

[0122] (1) 0.111 g of pirfenidone is weighed, 8.889 g of dichloromethane is added, and the drug is fully dissolved through ultrasonic treatment; the above solution is filtered through a needle type nylon filter head and reserved.

[0123] (2) 1 g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=31400 Da, carboxyl end-capped) is weighed and added to the above solution, and ultrasonic treatment is performed to obtain an oil phase solution.

[0124] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0125] (4) The oil phase and the aqueous phase are respectively injected into a microfluidic device through a syringe pump, the flow rate of the oil phase is adjusted to 20 μl / min, and the flow rate of the aqueous phase is adjusted to 600 μl / min; the continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and microspheres are collected;

[0126] (5) The collected microspheres are transferred into a volatilizer, and stirring is performed at 150 rpm; the volatilizer is subjected to programmed temperature drying (15 ℃ for 1 h, 25 ℃ for 1 h, and 35 ℃ for 1 h); and the organic solvent is volatilized.

[0127] (6) After washing, filtering and drying, pirfenidone long-acting sustained-release microspheres are obtained.

[0128] Example 3:

[0129] The embodiment provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, and comprises the following steps:

[0130] (1) 0.111 g of pirfenidone is weighed, 8.889 g of dichloromethane is added, and the drug is fully dissolved through ultrasonic treatment; the above solution is filtered through a needle type nylon filter head and reserved.

[0131] (2) 1 g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=31400 Da, carboxyl end-capped) is weighed and added to the above solution, and ultrasonic treatment is performed to obtain an oil phase solution.

[0132] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0133] (4) The oil phase and the aqueous phase are respectively injected into a microfluidic device through a syringe pump, the flow rate of the oil phase is adjusted to 20 μl / min, and the flow rate of the aqueous phase is adjusted to 600 μl / min; the continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and microspheres are collected;

[0134] (5) The collected microspheres are transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h) to volatilize the organic solvent.

[0135] (6) The obtained pirfenidone long-acting sustained-release microspheres are washed with pure water, filtered, and dried.

[0136] Example 4

[0137] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0138] (1) 0.111 g of pirfenidone is weighed and added to 8.889 g of dichloromethane, and the drug is fully dissolved by ultrasonic treatment. The solution is filtered with a needle-type nylon filter head for standby.

[0139] (2) 1 g of polylactic acid-glycolic acid copolymer (LA:GA = 65:35, Mw = 32500 Da, carboxyl-terminated) is weighed and added to the above solution, and is dissolved by ultrasonic treatment to obtain an oil phase solution.

[0140] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0141] (4) The oil phase and the aqueous phase are respectively injected into a microfluidic device by using a syringe pump, the flow rate of the oil phase is adjusted to 20 μl / min, and the flow rate of the aqueous phase is adjusted to 600 μl / min. The continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and the microspheres are collected.

[0142] (5) The collected microspheres are transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h) to volatilize the organic solvent.

[0143] (6) The obtained pirfenidone long-acting sustained-release microspheres are washed with pure water, filtered, and dried.

[0144] Example 5

[0145] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0146] (1) 0.111 g of pirfenidone is weighed and added to 8.889 g of dichloromethane, and the drug is fully dissolved by ultrasonic treatment. The solution is filtered with a needle-type nylon filter head for standby.

[0147] (2) 1 g of polylactic acid-glycolic acid copolymer (LA:GA = 65:35, Mw = 32500 Da, carboxyl-terminated) is weighed and added to the above solution, and is dissolved by ultrasonic treatment to obtain an oil phase solution.

[0148] (3) Prepare 0.5wt% polyvinyl alcohol solution as the aqueous phase solution.

[0149] (4) Inject the oil phase and the aqueous phase into the microfluidic device respectively by using the syringe pump, adjust the flow rate of the oil phase to 20 μl / min and the flow rate of the aqueous phase to 600 μl / min, the continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and collect the microspheres;

[0150] (5) Transfer the collected microspheres into a volatilizer, stir at 150 rpm, and perform programmed temperature drying (15℃ for 1 h, 25℃ for 1 h, and 35℃ for 1 h) to volatilize the organic solvent.

[0151] (6) Wash, filter, and dry to obtain the pirfenidone long-acting sustained-release microspheres.

[0152] Example 6:

[0153] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0154] (1) Weigh 0.111 g of pirfenidone, add 8.889 g of dichloromethane, and ultrasonically dissolve the drug. Filter the above solution with a needle type nylon filter head for standby.

[0155] (2) Weigh 1 g of polylactic acid-glycolic acid copolymer (LA:GA = 75:25, Mw = 32400 Da, ester group terminated), and add it to the above solution and ultrasonically dissolve to obtain an oil phase solution.

[0156] (3) Prepare 0.5wt% polyvinyl alcohol solution as the aqueous phase solution.

[0157] (4) Inject the oil phase and the aqueous phase into the microfluidic device respectively by using the syringe pump, adjust the flow rate of the oil phase to 20 μl / min and the flow rate of the aqueous phase to 600 μl / min, the continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and collect the microspheres;

[0158] (5) Transfer the collected microspheres into a volatilizer, stir at 150 rpm, and perform programmed temperature drying (15℃ for 1 h, 25℃ for 1 h, and 35℃ for 1 h) to volatilize the organic solvent.

[0159] (6) Wash, filter, and dry to obtain the pirfenidone long-acting sustained-release microspheres.

[0160] Example 7:

[0161] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0162] (1) Weigh 0.25g of perampanel, add 8.75g of dichloromethane, sonicate to fully dissolve the drug, filter the above solution with a needle nylon filter, and set aside.

[0163] (2) Weigh 1g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=13000Da, carboxyl-terminated), add it to the above solution, and dissolve it by sonication to obtain the oil phase solution.

[0164] (3) Prepare a 0.5 wt% polyvinyl alcohol solution as an aqueous phase solution.

[0165] (4) Inject the oil phase and water phase into the microfluidic device using a syringe pump, adjust the flow rate of the oil phase to 20 μl / min and the flow rate of the water phase to 600 μl / min. The continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and collect the microspheres.

[0166] (5) Transfer the collected microspheres into an evaporator, stir at 150 rpm, and dry by programmed temperature increase (15℃ for 1 h, 25℃ for 1 h, 35℃ for 1 h) to evaporate the organic solvent.

[0167] (6) After washing with pure water, filtering and drying, the long-acting sustained-release microspheres of perampanel are obtained.

[0168] Example 8:

[0169] This embodiment presents a method for preparing a sustained-release microsphere formulation containing perampanel, comprising the following steps:

[0170] (1) Weigh 0.429g of perampanel, add 8.571g of dichloromethane, sonicate to fully dissolve the drug, filter the above solution with a needle nylon filter, and set aside.

[0171] (2) Weigh 1g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=13000Da, carboxyl-terminated), add it to the above solution, and dissolve it by sonication to obtain the oil phase solution.

[0172] (3) Prepare a 0.5 wt% polyvinyl alcohol solution as an aqueous phase solution.

[0173] (4) Inject the oil phase and water phase into the microfluidic device using a syringe pump, adjust the flow rate of the oil phase to 20 μl / min and the flow rate of the water phase to 600 μl / min. The continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and collect the microspheres.

[0174] (5) Transfer the collected microspheres into an evaporator, stir at 150 rpm, and dry by programmed temperature increase (15℃ for 1 h, 25℃ for 1 h, 35℃ for 1 h) to evaporate the organic solvent.

[0175] (6) After washing with pure water, filtering and drying, the long-acting sustained-release microspheres of pirfenidone are obtained.

[0176] Example 9

[0177] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0178] (1) 0.111 g of pirfenidone is weighed and added to 8.889 g of dichloromethane, and the drug is fully dissolved by ultrasonic treatment. The above solution is filtered with a needle type nylon filter head for standby.

[0179] (2) 1 g of polylactic acid-glycolic acid copolymer (LA: GA = 50:50, Mw = 55800 Da, carboxyl-terminated) is weighed and added to the above solution, and is dissolved by ultrasonic treatment to obtain an oil phase solution.

[0180] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0181] (4) The oil phase and the aqueous phase are respectively injected into a microfluidic device by using a syringe pump, the flow rate of the oil phase is adjusted to 20 μl / min, and the flow rate of the aqueous phase is adjusted to 900 μl / min. The continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and the microspheres are collected.

[0182] (5) The collected microspheres are transferred into a volatilizer, and are stirred at 150 rpm. The temperature is programmed to increase (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h) to volatilize the organic solvent.

[0183] (6) After washing with pure water, filtering and drying, the long-acting sustained-release microspheres of pirfenidone are obtained.

[0184] Example 10

[0185] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0186] (1) 0.111 g of pirfenidone is weighed and added to 8.889 g of dichloromethane, and the drug is fully dissolved by ultrasonic treatment. The above solution is filtered with a needle type nylon filter head for standby.

[0187] (2) 1 g of polylactic acid-glycolic acid copolymer (LA: GA = 50:50, Mw = 55800 Da, carboxyl-terminated) is weighed and added to the above solution, and is dissolved by ultrasonic treatment to obtain an oil phase solution.

[0188] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0189] (4) The oil phase and the water phase are injected into the microfluidic device by injection pump, the flow rate of the oil phase is adjusted to 20 μl / min, and the flow rate of the water phase is adjusted to 1200 μl / min, the continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and the microspheres are collected;

[0190] (5) The collected microspheres are transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h), and the organic solvent is volatilized.

[0191] (6) After washing with pure water, filtering, and drying, the pirfenidone long-acting sustained-release microspheres are obtained.

[0192] Example 11:

[0193] The embodiment provides a preparation method of a sustained-release microsphere preparation containing a pirfenidone drug, including the following steps:

[0194] (1) 0.125 g of pirfenidone is weighed, 9.375 g of dichloromethane is added, and the drug is fully dissolved by ultrasonic, and the above solution is filtered by a needle type nylon filter head for standby.

[0195] (2) 0.5 g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=13000 Da, carboxyl end-capped) is weighed and added to the above solution, and is dissolved by ultrasonic to obtain an oil phase solution.

[0196] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as a water phase solution.

[0197] (4) The oil phase and the water phase are injected into the microfluidic device by injection pump, the flow rate of the oil phase is adjusted to 20 μl / min, and the flow rate of the water phase is adjusted to 1200 μl / min, the continuous phase in the microfluidic device shears the dispersed phase to obtain an oil-in-water emulsion, and the microspheres are collected;

[0198] (5) The collected microspheres are transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h), and the organic solvent is volatilized.

[0199] (6) After washing with pure water, filtering, and drying, the pirfenidone long-acting sustained-release microspheres are obtained.

[0200] Example 12:

[0201] The embodiment provides a preparation method of a sustained-release microsphere preparation containing a pirfenidone drug, including the following steps:

[0202] (1) 0.125 g of pirfenidone is weighed, 9.375 g of dichloromethane is added, and the drug is fully dissolved by ultrasonic, and the above solution is filtered by a needle type nylon filter head for standby.

[0203] (2) 0.8 g of polylactic acid-glycolic acid copolymer (LA:GA = 50:50, Mw = 13000 Da, carboxyl-terminated) was weighed and added to the above solution, and ultrasonically dissolved to obtain an oil phase solution.

[0204] (3) A 0.5 wt% polyvinyl alcohol solution was prepared as an aqueous phase solution.

[0205] (4) The oil phase and the aqueous phase were separately injected into a microfluidic device by using a syringe pump, the flow rate of the oil phase was adjusted to 20 μl / min, and the flow rate of the aqueous phase was adjusted to 600 μl / min, the continuous phase in the microfluidic device sheared the dispersed phase to obtain an oil-in-water emulsion, and microspheres were collected;

[0206] (5) The collected microspheres were transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h), and the organic solvent was volatilized.

[0207] (6) After washing with pure water, filtration, and drying, pirfenidone long-acting sustained-release microspheres were obtained.

[0208] Example 13:

[0209] The present example provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, which comprises the following steps:

[0210] (1) 0.125 g of pirfenidone was weighed and added to 9.375 g of dichloromethane, and ultrasonically dissolved to obtain an oil phase solution.

[0211] (2) 0.5 g of polylactic acid-glycolic acid copolymer (LA:GA = 50:50, Mw = 13000 Da, carboxyl-terminated) was weighed and added to the above solution, and ultrasonically dissolved to obtain an oil phase solution.

[0212] (3) A 0.5 wt% polyvinyl alcohol solution was prepared as an aqueous phase solution.

[0213] (4) The oil phase and the aqueous phase were separately injected into a microfluidic device by using a syringe pump, the flow rate of the oil phase was adjusted to 20 μl / min, and the flow rate of the aqueous phase was adjusted to 600 μl / min, the continuous phase in the microfluidic device sheared the dispersed phase to obtain an oil-in-water emulsion, and microspheres were collected;

[0214] (5) The collected microspheres were transferred into a volatilizer, stirred at 150 rpm, and dried by programmed temperature (15°C for 1 h, 25°C for 1 h, and 35°C for 1 h), and the organic solvent was volatilized.

[0215] (6) After washing with pure water, filtration, and drying, pirfenidone long-acting sustained-release microspheres were obtained.

[0216] Example 14:

[0217] The embodiment provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, and comprises the following steps.

[0218] (1) 0.125 g of pirfenidone is weighed, 9.375 g of dichloromethane is added, and the drug is fully dissolved through ultrasonic treatment; the above solution is filtered through a needle type nylon filter head and reserved.

[0219] (2) 0.5 g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=13000 Da, carboxyl end-capped) is weighed and added to the above solution, and ultrasonic treatment is performed to obtain an oil phase solution.

[0220] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0221] (4) The oil phase and the aqueous phase are respectively injected into a microfluidic device through a syringe pump, the flow rate of the oil phase is adjusted to 20 μl / min, the flow rate of the aqueous phase is adjusted to 600 μl / min, the continuous phase in the microfluidic device shears the dispersed phase, an oil-in-water emulsion is obtained, and microspheres are collected;

[0222] (5) The collected microspheres are transferred into a volatilizer, stirred at 150 rpm, dried at 40 ℃ for 4 h, and the organic solvent is volatilized.

[0223] (6) After washing, filtering and drying, pirfenidone long-acting sustained-release microspheres are obtained.

[0224] Embodiment 15

[0225] The embodiment provides a preparation method of a sustained-release microsphere preparation containing pirfenidone, and comprises the following steps:

[0226] (1) 0.125 g of pirfenidone is weighed, 9.375 g of dichloromethane is added, and the drug is fully dissolved through ultrasonic treatment; the above solution is filtered through a needle type nylon filter head and reserved.

[0227] (2) 0.5 g of polylactic acid-glycolic acid copolymer (LA:GA=50:50, Mw=13000 Da, carboxyl end-capped) is weighed and added to the above solution, and ultrasonic treatment is performed to obtain an oil phase solution.

[0228] (3) A 0.5 wt% polyvinyl alcohol solution is prepared as an aqueous phase solution.

[0229] (4) The oil phase and the aqueous phase are respectively injected into a microfluidic device through a syringe pump, the flow rate of the oil phase is adjusted to 20 μl / min, the flow rate of the aqueous phase is adjusted to 600 μl / min, the continuous phase in the microfluidic device shears the dispersed phase, an oil-in-water emulsion is obtained, and microspheres are collected;

[0230] (5) The collected microspheres are transferred into a volatilizer, stirred at 150 rpm, dried at 40 ℃ for 6 h, and the organic solvent is volatilized.

[0231] (6) Pure water washing, filtration, drying, and then the long-acting sustained-release pirfenidone microspheres are obtained.

[0232] Example 16.

[0233] This example proposes a preparation method of a sustained-release microsphere preparation containing pirfenidone drug, comprising the following steps:

[0234] (1) 0.25 g of pirfenidone was weighed and added to 8.75 g of dichloromethane, and the drug was fully dissolved by ultrasonic. The above solution was filtered with a needle type nylon filter head for standby.

[0235] (2) 1 g of polylactic acid-glycolic acid copolymer (LA: GA = 50:50, Mw = 55800 Da, carboxyl terminated) was weighed and added to the above solution, and dissolved by ultrasonic to obtain an oil phase solution.

[0236] (3) A 0.5 wt% polyvinyl alcohol solution was prepared as an aqueous phase solution.

[0237] (4) The oil phase and the aqueous phase were respectively injected into the microfluidic device by using a syringe pump, the flow rate of the oil phase was adjusted to 20 μl / min, and the flow rate of the aqueous phase was adjusted to 600 μl / min. The continuous phase in the microfluidic device sheared the dispersed phase to obtain an oil-in-water emulsion, and the microspheres were collected.

[0238] (5) The collected microspheres were transferred into a volatilizer, stirred at 150 rpm, and dried at 40°C for 4 h to volatilize the organic solvent.

[0239] (6) Pure water washing, filtration, drying, and then the long-acting sustained-release pirfenidone microspheres are obtained.

[0240] Example 17

[0241] The microspheres prepared in Example 7 and Example 16 were mixed in a weight ratio of 6:4.

[0242] Example 18.

[0243] The microspheres prepared in Example 7 and Example 16 were mixed in a weight ratio of 5:5.

[0244] Example 19.

[0245] The microspheres prepared in Example 7 and Example 16 were mixed in a weight ratio of 3:7.

[0246] General characterization of the pirfenidone / PLGA microspheres prepared in the preceding embodiments 1-19 and methods thereof, main properties include morphology, drug loading, encapsulation efficiency, dichloromethane residue, water content, in vitro release, etc. The relevant characterization methods and results are as follows: (1) Morphology: phenom desktop scanning electron microscope was used to observe and take pictures of the morphology. A small amount of microsphere powder was taken out on the tray with conductive glue, and nitrogen blowing was used to remove the unattached microspheres to obtain a single layer of microsphere sample, then gold spraying was performed using a sputtering instrument (SBC-12 ion sputtering instrument, Shanghai Minyi Electronics Co., Ltd., 8-10 mA, 30 s), and then the machine was taken to take pictures; see Figure 1 ; (2) Drug loading and encapsulation efficiency: about 5 mg of sample was weighed and added into 1 mL of N-methyl pyrrolidone (NMP) for dissolution, then HPLC was used to detect the pirfenidone content, and the drug loading and encapsulation efficiency of the PLGA pirfenidone microspheres were calculated; see Table 2;

[0247] (3) Dichloromethane residue: gas chromatograph was used to detect the residual amount of dichloromethane in the microspheres; see Table 2;

[0248] Table 2: Drug loading, encapsulation efficiency and dichloromethane residue detection results of microspheres

[0249] Example Drying procedure Drying time Methylene chloride residue Drug loading Encapsulation efficiency 11 15°C 1 h - 25°C 1 h - 35°C 1 h 3h 90 30 mg / kg 17.22 86.15 13 40℃ 3h 81 20 mg / kg 18.32 91.57 14 40℃ 4h 79 60 mg / kg 16.44 82.22 15 40℃ 6h 79 0 mg / kg 18.64 93.20

[0250] (4) In vitro release: the specific process of the drug in vitro release detection experiment is as follows:

[0251] 1) 0.01 mol / L physiological isotonic phosphate buffer solution, pH 7.4, containing 0.05% poloxamer and 0.05% sodium azide was prepared;

[0252] 2) The prepared pirfenidone long-acting sustained-release microspheres were precisely weighed and placed in a test tube, and added into 30 mL of physiological isotonic phosphate buffer solution (the release medium was phosphate buffer containing 1.0% (w / w) Tween 80, pH = 7.2), and placed in a constant temperature incubator at 37°C, with a shaking speed of 150 rpm;

[0253] 3) Samples were taken respectively, and after filtration, HPLC-UV method was used to measure the active drug content in the sample liquid medium, and the cumulative release rate was calculated.

[0254] The drug in vitro release results are shown in Figures 2-6 . Among them:

[0255] Figure 2The in vitro release of Examples 1, 2, 3, 4, 5, 6 was detected, the release medium was phosphate buffer containing 1.0% (w / w) Tween 80, pH = 7.2, the release condition was 37°C constant temperature water bath, 150 rpm shaking speed. When sampling, the microspheres were completely settled, 5 ml of the upper release medium was taken out, and the corresponding volume of the release medium was supplemented, and the pH of the release medium was monitored to keep it at about pH = 7.2. The content of pirfenidone was determined, and the cumulative release rate was calculated. The results showed that the end group, molecular weight and L / G of PLGA had great influence on the in vitro release. When L / G = 75 / 25 and the ester group was at the end, the microspheres released the slowest and were completely released in about 114 days. With the same end group, the greater the proportion of G, the faster the release. With the same PLGA, the smaller the molecular weight, the faster the release. Therefore, by adjusting the type of PLGA, microspheres with different sustained release periods can be obtained.

[0256] Figure 3 The in vitro release of Examples 1, 7, 8 was detected, the release medium was phosphate buffer containing 1.0% (w / w) Tween 80, pH = 7.2, the release condition was 37°C constant temperature water bath, 150 rpm shaking speed. When sampling, the microspheres were completely settled, 5 ml of the upper release medium was taken out, and the corresponding volume of the release medium was supplemented, and the pH of the release medium was monitored to keep it at about pH = 7.2. The content of pirfenidone was determined, and the cumulative release rate was calculated. The results showed that the theoretical drug loading had an influence on the in vitro release. When the theoretical drug loading was 10%-30%, the higher the theoretical drug loading, the higher the initial burst, but the in vitro release could be maintained for about 40 days.

[0257] Figure 4 The in vitro release of Examples 3, 9, 10 was detected, the release medium was phosphate buffer containing 1.0% (w / w) Tween 80, pH = 7.2, the release condition was 37°C constant temperature water bath, 150 rpm shaking speed. When sampling, the microspheres were completely settled, 5 ml of the upper release medium was taken out, and the corresponding volume of the release medium was supplemented, and the pH of the release medium was monitored to keep it at about pH = 7.2. The content of pirfenidone was determined, and the cumulative release rate was calculated. The results showed that the particle size of the microspheres had little effect on the in vitro release behavior, but the greater the oil-water phase flow rate ratio, the more difficult the preparation process, so the oil-water phase flow rate ratio of 20:600 was selected to prepare the microspheres.

[0258] Figure 5The in-vitro release of examples 7, 11 and 12 is shown, the release medium is phosphate buffer solution containing 1.0% (w / w) Tween 80, pH = 7.2, the release condition is 37℃ constant temperature water bath, 150 rpm shaking speed. When sampling, the microspheres are completely settled, 5ml of the upper release medium is taken out, and the corresponding volume of the release medium is supplemented, and the pH of the release medium is monitored to keep it at about pH = 7.2. The content of pirfenidone is determined, and the cumulative release rate is calculated, and the results show that the PLGA concentration has little effect on the in-vitro release behavior, and considering the cost, the PLGA concentration of 5% is selected to prepare the microspheres.

[0259] Figure 6 The in-vitro release of examples 17, 18 and 19 is shown, the release medium is 0.01 mol / L physiological isotonic phosphate buffer solution, pH 7.4, containing 0.05% poloxamer and 0.05% sodium azide, the release condition is 37℃ constant temperature water bath, 150 rpm shaking speed. When sampling, the microspheres are completely settled, 5ml of the upper release medium is taken out, and the corresponding volume of the release medium is supplemented, and the pH of the release medium is monitored to keep it at about pH = 7.4. The release rate of pirfenidone is determined. The results show that the in-vitro release of the mixed microspheres can be maintained for about 80 days.

[0260] In summary, the long-acting sustained and controlled release microspheres of pirfenidone of the application are very uniform by using microfluidic preparation of PLGA microspheres. In the in-vitro release experiment, the microspheres can stably release the drug, and the preferred release curve is grade 0, and the sustained release period is at least 4 weeks, and the more preferred sustained release period is 2 months or even longer. The application provides a new idea for regulating the sustained release period, and by mixing a single prescription in different proportions, a prescription with a longer sustained release period and more stable release can be obtained, and the development of stable controlled release pirfenidone long-acting microsphere preparation can effectively solve the problems of current immediate release dosage forms, such as "easy to miss medicine, drug discontinuation, large blood drug fluctuation, and difficult to control drug abuse", and in theory, it can also provide an effective strategy for the control of narcotic and psychotropic drugs. The drug loading effect of the pirfenidone / PLGA sustained release microspheres of the application is also better than that of the traditional method, which can significantly reduce the waste of drugs and increase efficiency. In addition, the microfluidic preparation method has no amplification effect, and can be linearly amplified by modifying the chip to increase the channels, and at the same time, it is convenient to realize the whole process of sterilization, and compared with the traditional preparation method, it has a more convenient production process transfer, and also has a higher technical barrier, which is beneficial to the transformation to products.

Claims

1. Mixed pirfenidone long-acting controlled-release microspheres characterized in that: The mixture comprises at least two kinds of pirfenidone long-acting controlled-release microspheres; the pirfenidone long-acting controlled-release microsphere A is prepared by using PLGA with a weight average molecular weight of 13000 Da, the pirfenidone long-acting controlled-release microsphere B is prepared by using PLGA with a weight average molecular weight of 55800 Da, and the pirfenidone long-acting controlled-release microsphere A and the pirfenidone long-acting controlled-release microsphere B are mixed according to the following weight ratio: 3-7 parts of the pirfenidone long-acting controlled-release microsphere A and 3-7 parts of the pirfenidone long-acting controlled-release microsphere B, and the total weight of the two is 10 parts; The pirfenidone long-acting controlled-release microspheres are prepared by using a microfluidic method from an inner phase solution and an outer phase solution; The inner phase solution comprises pirfenidone, PLGA and a good solvent for the two, and is composed of the following weight ratio: The mass fraction of PLGA in the inner phase solution is 2.0-40.0 wt%; The theoretical drug loading of pirfenidone is 5.0-60.0 wt%; The inner phase good solvent is the remainder; The theoretical drug loading of pirfenidone is calculated by the formula: the mass of pirfenidone divided by the sum of the masses of pirfenidone and PLGA; The outer phase solution comprises a surfactant and a good solvent for the surfactant, and an inner phase good solvent, and is composed of the following weight ratio: A small amount of the inner phase good solvent is added to the outer phase solution so that it is saturated in the outer phase solution; The main solvent of the outer phase solution is a good solvent for the surfactant which is not miscible with the inner phase good solvent in any ratio; The good solvent for the surfactant is the remainder.

2. The mixed pirfenidone long-acting controlled-release microspheres according to claim 1, characterized by: The inner phase solution comprises pirfenidone, PLGA and a good solvent for the two, and is composed of the following weight ratio: The mass fraction of PLGA in the inner phase solution is 5.0-25.0 wt%; The theoretical drug loading of pirfenidone is 10-40.0 wt%; The inner phase good solvent is the remainder.

3. The mixed pirfenidone long-acting controlled-release microspheres according to claim 1, characterized by: The mass fraction of PLGA in the inner phase solution is 5.0-10.0 wt%.

4. The mixed pirfenidone long-acting controlled-release microspheres according to claim 1, characterized by: The theoretical drug loading of pirfenidone is 10.0-30.0 wt%.

5. The mixed pirfenidone long-acting controlled-release microspheres according to claim 1, characterized by: The outer phase solution comprises a surfactant and a good solvent for the surfactant, and an inner phase good solvent, and is composed of the following weight ratio: The mass fraction of the surfactant in the outer phase solution is 0.5-2.0 wt%; A small amount of the inner phase good solvent is added to the outer phase solution so that it is saturated in the outer phase solution; The main solvent of the outer phase solution is a good solvent for the surfactant which is not miscible with the inner phase good solvent in any ratio; The good solvent for the surfactant is the remainder.

6. The mixed pirfenidone long-acting controlled-release microspheres according to any one of claims 1 to 5, characterized by: At least any one of the following is satisfied: The PLGA is polylactic acid-glycolic acid copolymer, and the ratio of lactide (LA) to glycolide (GA) is LA:GA=(95:5)-(5:95); In the inner phase solution, the inner phase good solvent is any one of dichloromethane, ethyl acetate, chloroform and acetone; In the outer phase solution, the surfactant comprises any one or more of PVA, poloxamer or PVP; In the outer phase solution, the good solvent for the surfactant is water or other solvent which is not miscible with the inner phase good solvent in any ratio.

7. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: LA:GA=(75:25)-(25:75).

8. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: LA:GA = (75:25) to (50:50).

9. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: In the internal phase solution, the internal phase good solvent is dichloromethane.

10. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: In the external phase solution, the surfactant is PVA.

11. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: The PVA is any one or more of PVA1788, PVA1799, and PVA0588.

12. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: The PVA is PVA1788.

13. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: The external phase solvent is water.

14. The mixed pirfenidone long-acting controlled-release microspheres according to claim 6, characterized by: The water is pure water, water for injection, deionized water, or double-distilled water.

15. The mixed pirfenidone long-acting controlled-release microspheres according to claim 1, characterized by: 3 parts of long-acting controlled-release pirfenidone microspheres A, 7 parts of long-acting controlled-release pirfenidone microspheres B; or 5 parts of long-acting controlled-release pirfenidone microspheres A, 5 parts of long-acting controlled-release pirfenidone microspheres B; or 6 parts of long-acting controlled-release pirfenidone microspheres A, 4 parts of long-acting controlled-release pirfenidone microspheres B.

16. A pirfenidone microsphere injection formulation characterized by: It is a solvent prepared by adding a pharmaceutically common excipient or auxiliary ingredient to the mixed long-acting controlled-release pirfenidone microspheres according to any one of claims 1-15 to prepare an injection preparation.

17. The process for the preparation of mixed pirfenidone long acting controlled release microspheres as claimed in claim 1 wherein: The specific steps are as follows: A. According to the internal phase solution and the external phase solution, weigh each raw material and excipient; B. Prepare the internal phase solution: use the internal phase good solvent to fully dissolve pirfenidone and PLGA to obtain the internal phase solution; C. Prepare the external phase solution: fully dissolve the surfactant and the good solvent for the surfactant, then add a small amount of internal phase solvent to saturate it in the external phase solution, fully stir, stand for stratification, take the supernatant, and obtain the external phase solution; D. Inject the internal phase solution and the external phase solution into the microfluidic device, control the flow rates of the internal phase solution and the external phase solution, obtain stable droplets, and then use a receiving liquid to receive the droplets to obtain a microemulsion; E. Dry and wash the microemulsion to obtain a microsphere suspension; F. Freeze-dry the microsphere suspension obtained in step E to obtain a microsphere powder.

18. The preparation method of the mixed long-acting controlled-release pirfenidone microspheres according to claim 17, at least satisfying any one of the following: The internal phase solution comprises pirfenidone, PLGA, and good solvents for both, and is composed of the following weight ratio: The mass fraction of PLGA in the internal phase solution is 2.0-40.0wt%; The theoretical drug loading of pirfenidone is 5.0-60.0wt%; The internal phase good solvent is the remainder; The theoretical drug loading of pirfenidone is calculated by dividing the mass of pirfenidone by the sum of the masses of pirfenidone and PLGA; The external phase solution comprises a surfactant, a good solvent for the surfactant, and an internal phase good solvent, and is composed of the following weight ratio: The mass fraction of the surfactant in the external phase solution is 0.1-5.0wt%; The external phase solution is saturated by adding a small amount of internal phase good solvent; The main solvent of the external phase solution is the good solvent for the surfactant, which is not miscible with the internal phase good solvent in any ratio; the good solvent for the surfactant is the remainder; In the external phase solution, the good solvent for the surfactant is water or other solvents that are not miscible with the internal phase good solvent in any ratio.

19. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The mass fraction of PLGA in the internal phase solution is 5.0-10.0wt%.

20. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The theoretical drug loading of pirfenidone is 10.0-30.0wt%.

21. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: In the internal phase solution, the internal phase good solvent is any one of dichloromethane, ethyl acetate, chloroform, and acetone.

22. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The inner phase good solvent is dichloromethane.

23. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The mass fraction of the surfactant in the outer phase solution is 0.5-2.0wt%.

24. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The surfactant in the outer phase solution comprises any one or more of PVA, poloxamer or PVP.

25. The method of claim 24, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The surfactant in the outer phase solution is PVA.

26. The method of claim 24, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The PVA is any one or more of PVA1788, PVA1799 or PVA0588.

27. The method of claim 24, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The PVA is PVA1788.

28. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The outer phase solvent is water.

29. The method of claim 18, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The water is pure water, water for injection, deionized water or double-distilled water.

30. The preparation method of the mixed pirfenidone long-acting controlled-release microspheres according to claim 17, at least satisfying any one of the following conditions: In step C, the surfactant-dissolved good solvent is prepared by adding any one of PVA, poloxamer or PVP into water heated to 90-98℃ under stirring. In step D, the flow rate of the inner phase solution is 5-200μL / min, and the flow rate of the outer phase solution is 300-2000μL / min, while the flow rate of the outer phase solution is controlled to be greater than that of the inner phase solution. In step D, the receiving liquid has the same concentration of surfactant as the outer phase solution. The drying described in step E employs drying in liquid; wherein, The liquid drying is carried out by placing the microemulsion in a liquid under the conditions of 4-40℃ and 60-240rpm for 2-6h. In step E, the washing is carried out by taking the microspheres after drying or liquid drying in step E, discarding the supernatant, adding an appropriate amount of pure water for resuspension, and then using any one of the following methods for washing: 1) filtering the microspheres using a 400-500 mesh metal filter; repeating the pure water resuspension and filtration until the foaming effect of PVA disappears; in the last filtration, the water in the microspheres is completely filtered out, and the microspheres retained on the filter are taken and resuspended in a certain amount of pure water to obtain the microsphere suspension; 2) centrifuging the microsphere sample at 2000rpm-8000rpm for 3-10min, and discarding the supernatant; repeating the pure water resuspension and centrifugation to remove the supernatant until the foaming effect of PVA disappears; after the last centrifugation, a certain amount of pure water is added for resuspension to obtain the microsphere suspension; In step F, the freeze-drying is carried out under the conditions of -45℃ or lower, a vacuum degree of 15Pa or lower, and a freeze-drying time of 24-96h.

31. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: In step C, the surfactant-dissolved good solvent is prepared by adding any one of PVA, poloxamer or PVP into water heated to 95℃ under stirring.

32. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: In step D, the flow rate of the inner phase solution is 30-110μL / min, and the flow rate of the outer phase solution is 450-1200μL / min, while the flow rate of the outer phase solution is controlled to be greater than that of the inner phase solution.

33. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: In step D, the flow rate of the inner phase solution is 30-110μL / min, and the flow rate of the outer phase solution is 600-1200μL / min, while the flow rate of the outer phase solution is controlled to be greater than that of the inner phase solution.

34. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The liquid drying is carried out by placing the microemulsion in a liquid under the conditions of 35-40℃ and 150-180rpm for 3-4h.

35. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: In step E, the liquid drying is carried out by placing the microemulsion in a liquid under the conditions of 40℃ and 150rpm for 4h.

36. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: In step 1), a 500 mesh metal filter is used; a 400 mesh metal filter has a pore size of 38 microns, and a 500 mesh metal filter has a pore size of 13 microns, which is suitable for filtering large and small particle sizes and removing unstable small particles.

37. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: Step 1) The number of washing times is not less than 5, and the volume of each washing is not less than 500 mL / 0.5 g of microspheres.

38. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: Step 2) The microsphere sample is centrifuged under the condition of 2000 rpm for 3 min.

39. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: Step 2) The number of resuspension and centrifugation is not less than 5, and the volume of each resuspension is not less than 500 mL / 0.5 g of microspheres.

40. The method of claim 30, wherein the mixed pirfenidone long-acting controlled release microspheres are prepared by: The freeze-drying time is 48 h.

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