Donepezil sustained-release microspheres, and preparation method, pharmaceutical preparation and application thereof

Abstract

The invention provides donepezil sustained-release microspheres and a preparation method, a pharmaceutical preparation and application thereof. The preparation method comprises the following steps: forming a water phase (containing a surfactant, an osmotic pressure regulator and water, and regulating the pH value with a pH regulator); forming an oil phase (comprising donepezil, a carrier material and an organic solvent); and adding the oil phase into the water phase, dispersing to form a pre-emulsion, performing membrane emulsification on the pre-emulsion to form an emulsion, and finally curing, washing and freeze-drying the emulsion to obtain the donepezil sustained-release microspheres. The preparation process is stable and controllable, the batch-to-batch repeatability is good, the surface of the microsphere is smooth and complete, the particle size distribution is uniform, the size is controllable, the microsphere has high drug loading capacity, long-term stable release can be realized, the injectability is excellent, the administration frequency can be reduced, and the adverse reaction of gastrointestinal tracts can be reduced.

Description

Technical Field

[0001] The present invention belongs to the field of pharmaceutical preparations, and relates to a donepezil sustained-release microsphere, a preparation method thereof, a pharmaceutical preparation and uses thereof. Background Art

[0002] Alzheimer's disease (AD) is a chronic neurodegenerative disease that generally occurs in the pre-senile and senile stages. Its main manifestations include progressive memory impairment, cognitive dysfunction, personality changes, language disorders and other symptoms, which seriously affect social, occupational and life functions.

[0003] Due to the very complex pathogenesis of Alzheimer's disease, current drug treatments and other intervention measures cannot cure Alzheimer's disease. Most of the mechanisms of drug treatment are to regulate some neurotransmitters in the brain, mainly to relieve symptoms and delay the development of the disease, so the treatment effect is limited.

[0004] The disorder of cortical cholinergic neurotransmitter function is considered to be one of the causes of memory impairment and other cognitive dysfunctions. Currently approved drugs for the treatment of AD are acetylcholinesterase (AChE) inhibitors and N-methyl-D-aspartic acid (NMDA) receptor antagonists. Donepezil is a second-generation central acetylcholinesterase inhibitor (AChEI), which has the characteristics of high pharmacological activity, strong selectivity, good safety, high lipid solubility, easy penetration through the blood-brain barrier, strong affinity with acetylcholinesterase, specifically binding to cholinesterase in the cerebral cortex, inhibiting cholinesterase activity, thus having high efficacy and few adverse reactions. It is currently a first-line drug for the clinical treatment of mild and moderate Alzheimer's disease.

[0005] Currently, most commercially available preparations are oral preparations of donepezil hydrochloride, including oral tablets, capsules, oral solutions, etc., which need to be administered once a day, and a treatment course lasts for 3 to 6 months. However, the memory of Alzheimer's disease patients decreases to varying degrees, and it is very easy to miss taking, take the wrong dose or even refuse to take the medicine. Moreover, when the disease develops to a certain extent, patients will also have problems with dysphagia, which are not conducive to improving the condition. In addition, taking oral donepezil hydrochloride has certain adverse reactions, such as nausea, vomiting, diarrhea, loss of appetite, etc. The control of Alzheimer's disease requires long-term maintenance, and long-term oral medication will lead to poor patient compliance and low medication accuracy.

[0006] The membrane emulsification method can prepare microspheres with uniform and controllable particle sizes, high encapsulation efficiency, and low mechanical strength. Due to different indications and administration routes of drugs, the in vivo environments where the microspheres are located also vary, thus different requirements are put forward for the types, particle sizes, and distributions of drug-loaded microspheres, etc., and therefore it is necessary to strictly control the parameter regulation, condition optimization, and improvement of related equipment in the membrane emulsification operation. For example, for hydrophilic polypeptide drugs and drugs with small molecular weights, drug escape is very likely to occur, and by adjusting factors such as the membrane pore size, types of organic solvents and related ratios, and stirring rate, microspheres with good encapsulation efficiency and drug loading can be obtained. In addition, researchers also found that when using the membrane emulsification technology, this operation process involves multidisciplinary knowledge and there are many influencing factors, and there is currently no complete theory to guide this preparation technology. Summary of the Invention

[0007] Problems to be Solved by the Invention

[0008] In view of the above problems, the present invention aims to provide a donepezil sustained-release microsphere preparation with uniform particle size, high drug loading, long-term stable release, excellent injectability, stable and controllable preparation process, and good repeatability between batches.

[0009] Solutions for Solving the Problems

[0010] In a first aspect, the present invention provides a method for preparing donepezil sustained-release microspheres, which comprises the following steps:

[0011] Mix a surfactant, an osmotic pressure regulator, and water, and adjust the pH value of the mixture using a pH regulator to form an aqueous phase;

[0012] Mix donepezil, a carrier material, and an organic solvent to form an oil phase; and,

[0013] Add the oil phase to the aqueous phase for dispersion to form a pre-emulsion, then subject the pre-emulsion to membrane emulsification to form an emulsion, and finally solidify the emulsion, wash, and lyophilize to obtain donepezil sustained-release microspheres.

[0014] As a further improvement of the present invention, the pre-emulsion is an oil-in-water type pre-emulsion.

[0015] As a further improvement of the present invention, the surfactant is at least one of polyvinyl alcohol (PVA), Tween, sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), and polyoxyethylene octylphenol ether, preferably polyvinyl alcohol.

[0016] As a further improvement of the present invention, the weight ratio of the surfactant to donepezil is 1:5 to 20:5, preferably 4:5 to 8:5.

[0017] As a further improvement of the present invention, the osmotic pressure regulator is at least one of sodium chloride and potassium chloride, preferably sodium chloride.

[0018] As a further improvement of the present invention, the weight ratio of the osmotic pressure regulator to donepezil is 1:5 to 6:5, preferably 1.5:5 to 4:5.

[0019] As a further improvement of the present invention, the water is at least one of ultrapure water, double-distilled water and water for injection, preferably ultrapure water.

[0020] As a further improvement of the present invention, the volume ratio of the water to the organic solvent is 5:1 to 50:1, preferably 8:1 to 14:1.

[0021] As a further improvement of the present invention, the pH regulator is at least one of hydrogen chloride and sodium hydroxide.

[0022] As a further improvement of the present invention, the pH regulator adjusts the pH value of the mixture to 6.0 to 12.0, preferably 6.0 to 10.0.

[0023] As a further improvement of the present invention, the carrier material is a biodegradable carrier material.

[0024] As a further improvement of the present invention, the carrier material is at least one of poly(lactic-co-glycolic acid) (PLGA), poly(lactic acid)-poly(ethylene glycol) copolymer (PELA) and poly(lactic acid) (PLA), preferably poly(lactic-co-glycolic acid).

[0025] As a further improvement of the present invention, the intrinsic viscosity of the carrier material is 0.15 dL / g to 0.90 dL / g, preferably 0.4 dL / g to 0.7 dL / g.

[0026] As a further improvement of the present invention, the weight ratio of the carrier material to donepezil is 2:3 to 12:3, preferably 2:3 to 5:3.

[0027] As a further improvement of the present invention, the organic solvent is at least one of chloroform, dichloromethane, ethyl acetate, acetone, acetonitrile and absolute ethanol, preferably dichloromethane.

[0028] As a further improvement of the present invention, the dosage ratio of the organic solvent to donepezil is 4 to 20 mL:1 g, preferably 6 to 15 mL:1 g.

[0029] As a further improvement of the present invention, the dispersion is completed by at least one of stirring and ultrasonication, preferably stirring, more preferably mechanical stirring.

[0030] As a further improvement of the present invention, the time of mechanical stirring is 30 to 60 s, preferably 30 s.

[0031] As a further improvement of the present invention, the rotation speed of the mechanical stirring is 250 to 350 rpm, preferably 300 rpm.

[0032] As a further improvement of the present invention, the emulsification is completed by membrane emulsification.

[0033] As a further improvement of the present invention, the curing is completed by volatilization or evaporation, preferably vacuum volatilization, stirring volatilization or thin-film evaporation, more preferably vacuum volatilization.

[0034] As a further improvement of the present invention, the vacuum degree of the vacuum volatilization is -0.09 to -0.05 MPa, preferably -0.09 MPa.

[0035] As a further improvement of the present invention, the time of the vacuum volatilization is 20 to 300 min, preferably 20 to 240 min.

[0036] As a further improvement of the present invention, the temperature of the vacuum volatilization is 20 to 42 °C, preferably 38 °C.

[0037] As a further improvement of the present invention, the preparation method further includes the following steps: washing and freeze-drying after curing the emulsion.

[0038] In a second aspect, the present invention provides a sustained-release microsphere of donepezil, which is prepared by using the above preparation method.

[0039] As a further improvement of the present invention, the particle size of the donepezil sustained-release microsphere is 10 to 50 μm, preferably 25 to 35 μm.

[0040] As a further improvement of the present invention, the encapsulation efficiency of the donepezil sustained-release microsphere is more than 80%, preferably more than 90%.

[0041] As a further improvement of the present invention, the drug loading of the donepezil sustained-release microsphere is 20% to 60%, preferably 40% to 60%.

[0042] In a third aspect, the present invention provides a pharmaceutical preparation of donepezil, which contains the above sustained-release microsphere.

[0043] As a further improvement of the present invention, the pharmaceutical preparation further contains at least one pharmaceutically acceptable excipient.

[0044] As a further improvement of the present invention, the pharmaceutical preparation is a sustained-release preparation.

[0045] As a further improvement of the present invention, the pharmaceutical preparation is an injection.

[0046] In a fourth aspect, the present invention provides the use of the above-mentioned sustained-release microspheres or the above-mentioned pharmaceutical preparation in the preparation of a medicament for preventing and / or treating at least some diseases and / or disorders related to acetylcholinesterase.

[0047] As a further improvement of the present invention, the at least some diseases and / or disorders related to acetylcholinesterase are Alzheimer's disease.

[0048] Effects of the Invention

[0049] The beneficial effects of the present invention are as follows:

[0050] (1) Using the preparation process of the present invention can reduce drug escape and avoid the risk of high initial burst release.

[0051] (2) The sustained-release microspheres prepared by the present invention carry a high content of donepezil, and the dosage of the microspheres is relatively small during drug administration (such as injection), avoiding injection nodules or other adverse reactions caused by a too large injection volume.

[0052] (3) The microspheres prepared by the present invention have uniform particle size and excellent injectability.

[0053] (4) The preparation process of the present invention is stable and controllable, with good economic benefits and broad application prospects.

[0054] (5) The long-acting sustained-release microsphere preparation prepared by the present invention can greatly reduce the drug administration frequency of patients, effectively avoiding fluctuations in blood drug concentration caused by missed or incorrect doses, and even recurrence or deterioration of the condition.

[0055] (6) The injectable microsphere preparation prepared by the present invention can effectively avoid gastrointestinal adverse reactions and has obvious clinical advantages. Description of the Drawings

[0056] Figure 1 is a scanning electron micrograph of the microspheres prepared in Example 1.

[0057] Figure 2 is a scanning electron micrograph of the microspheres prepared in Example 2.

[0058] Figure 3 is a scanning electron micrograph of the microspheres prepared in Example 3.

[0059] Figure 4 is a scanning electron micrograph of the microspheres prepared in Example 4.

[0060] Figure 5 is a scanning electron micrograph of the microspheres prepared in Example 5.

[0061] Figure 6It is the scanning electron microscope image of the microspheres prepared in Example 6.

[0062] Figure 7 It is the scanning electron microscope image of the microspheres prepared in Example 7.

[0063] Figure 8 It is the scanning electron microscope image of the microspheres prepared in Example 8.

[0064] Figure 9 It is the scanning electron microscope image of the microspheres prepared in Comparative Example 1.

[0065] Figure 10 It is the scanning electron microscope image of the microspheres prepared in Comparative Example 2.

[0066] Figure 11 It is the in vitro cumulative release curves of the five kinds of microspheres prepared in Example 1, 5, 6, 7 and 8. Detailed Description of the Invention

[0067] The following will detail various exemplary embodiments, features and aspects of the present invention. The special term "exemplary" used herein means "serving as an example, embodiment or illustration". Any embodiment described as "exemplary" here does not have to be construed as superior or better than other embodiments.

[0068] In addition, for better illustration of the present invention, numerous specific details are given in the following detailed description. Those skilled in the art should understand that the present invention can also be implemented without some specific details. In other instances, methods, means, equipment and steps well known to those skilled in the art are not described in detail so as to highlight the gist of the present invention.

[0069] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0070] In this specification, the meaning expressed by using "can" includes the meanings of both performing a certain process and not performing a certain process.

[0071] In this specification, the "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc. mentioned refer to the specific elements (e.g., features, structures, properties and / or characteristics) related to the embodiments described, which are included in at least one of the embodiments described herein, and may or may not exist in other embodiments. In addition, it should be understood that the elements can be combined in various embodiments in any suitable manner.

[0072] In this specification, the numerical range expressed by using "numerical value A to numerical value B" refers to the range including the endpoint numerical values A and B.

[0073] In this specification, when "normal temperature" or "room temperature" is used, the temperature can be 10 - 40°C.

[0074] Donepezil Sustained Release Microspheres and Preparation Method Thereof

[0075] The present invention provides a method for preparing donepezil sustained-release microspheres, which comprises the following steps:

[0076] Mix a surfactant, an osmotic pressure regulator and water, and adjust the pH value of the mixture using a pH regulator to form an aqueous phase;

[0077] Mix donepezil, a carrier material and an organic solvent to form an oil phase; and,

[0078] Add the oil phase to the aqueous phase for dispersion to form a pre-emulsion, then subject the pre-emulsion to membrane emulsification to form an emulsion, and finally solidify the emulsion, wash and lyophilize to obtain donepezil sustained-release microspheres.

[0079] During the preparation of donepezil, due to osmotic pressure and isoelectric point factors, the drug diffuses from the oil phase to the aqueous phase, causing the drug to migrate to the outside of the carrier material, resulting in too fast release at the initial stage of microsphere release and making it difficult to achieve long-term stable release. In addition, drug migration will also form drug crystals around or on the surface of the microspheres, making the surface of the microspheres rough and reducing the drug loading. In addition, the particle size of the microspheres has a great influence on the drug release behavior. The particle size distribution of the microspheres prepared by traditional preparation methods is not uniform, affecting the stable release of the drug. Therefore, it is particularly important to avoid drug escape and control the size of the microspheres during the preparation.

[0080] The present invention prevents the drug from migrating to the outside of the microspheres by adding a certain amount of osmotic pressure regulator to the aqueous phase and adjusting the pH value of the aqueous phase, making the surface of the microspheres smoother and having a higher drug loading, effectively avoiding sudden drug release and maintaining the stable drug release behavior. At the same time, an emulsion with a more uniform particle size is obtained by the membrane emulsification method. When the microspheres are washed and collected, no additional sieving is required, the size is controllable, effectively avoiding drug loss and enabling the drug to be released stably for a long time.

[0081] In one embodiment of the present invention, the pre-emulsion in the above preparation method can be an oil-in-water pre-emulsion.

[0082] In one embodiment of the present invention, the surfactant in the above preparation method can be at least one of polyvinyl alcohol, Tween, sodium dodecyl sulfate, sodium dodecyl benzene sulfonate and polyoxyethylene octylphenol ether, for example, polyvinyl alcohol, Tween or a mixture obtained by mixing the two in any proportion.

[0083] In one embodiment of the present invention, the surfactant in the above preparation method can be polyvinyl alcohol.

[0084] In one embodiment of the present invention, the weight ratio of the surfactant to donepezil in the above preparation method can vary within a certain range, for example, 1:5 to 20:5.

[0085] In one embodiment of the present invention, the weight ratio of the surfactant to donepezil in the above preparation method can be 4:5 to 8:5.

[0086] In one embodiment of the present invention, the osmotic pressure regulator in the above preparation method can be at least one of sodium chloride and potassium chloride, for example, sodium chloride, potassium chloride, or a mixture obtained by mixing the two in any proportion.

[0087] In one embodiment of the present invention, the osmotic pressure regulator in the above preparation method can be sodium chloride.

[0088] In one embodiment of the present invention, the weight ratio of the osmotic pressure regulator to donepezil in the above preparation method can vary within a certain range, for example, 1:5 to 6:5.

[0089] In one embodiment of the present invention, the weight ratio of the osmotic pressure regulator to donepezil in the above preparation method can be 1.5:5 to 4:5.

[0090] In one embodiment of the present invention, the water in the above preparation method can be at least one of ultrapure water, double-distilled water, and water for injection, for example, ultrapure water, water for injection, or a mixture obtained by mixing the two in any proportion.

[0091] In one embodiment of the present invention, the water in the above preparation method can be ultrapure water.

[0092] In one embodiment of the present invention, the volume ratio of water to the organic solvent in the above preparation method can vary within a certain range, for example, 5:1 to 50:1.

[0093] In one embodiment of the present invention, the weight ratio of water to donepezil in the above preparation method can be 8:1 to 14:1.

[0094] In one embodiment of the present invention, the pH regulator in the above preparation method can be at least one of hydrogen chloride and sodium hydroxide.

[0095] In one embodiment of the present invention, the pH regulator in the above preparation method can adjust the pH value of the mixture within a certain range, for example, 6.0 to 12.0.

[0096] In one embodiment of the present invention, the pH regulator in the above preparation method can adjust the pH value of the mixture to 6.0 to 10.0.

[0097] In one embodiment of the present invention, the carrier material in the above preparation method may be a biodegradable carrier material.

[0098] In one embodiment of the present invention, the carrier material in the above preparation method may be at least one of poly(lactic-co-glycolic acid), poly(lactic acid)-poly(ethylene glycol) copolymer, and polylactic acid, for example, poly(lactic-co-glycolic acid), poly(lactic acid)-poly(ethylene glycol) copolymer, or a mixture obtained by mixing the two in any ratio.

[0099] In one embodiment of the present invention, the carrier material in the above preparation method may be poly(lactic-co-glycolic acid).

[0100] In one embodiment of the present invention, the intrinsic viscosity of the carrier material in the above preparation method may be 0.15 dL / g to 0.90 dL / g. For example, the carrier material in the above preparation method may be poly(lactic-co-glycolic acid) with an intrinsic viscosity of 0.15 dL / g to 0.90 dL / g.

[0101] In one embodiment of the present invention, the intrinsic viscosity of the carrier material in the above preparation method may be 0.4 dL / g to 0.7 dL / g. For example, the carrier material in the above preparation method may be poly(lactic-co-glycolic acid) with an intrinsic viscosity of 0.4 dL / g to 0.7 dL / g.

[0102] In one embodiment of the present invention, the weight ratio of the carrier material to donepezil in the above preparation method may vary within a certain range, for example, 2:3 to 12:3.

[0103] In one embodiment of the present invention, the weight ratio of the carrier material to donepezil in the above preparation method may be 2:3 to 5:3.

[0104] In one embodiment of the present invention, the organic solvent in the above preparation method may be at least one of chloroform, dichloromethane, ethyl acetate, acetone, acetonitrile, and absolute ethanol, for example, dichloromethane, ethyl acetate, or a mixture obtained by mixing the two in any ratio.

[0105] In one embodiment of the present invention, the organic solvent in the above preparation method may be dichloromethane.

[0106] In one embodiment of the present invention, the dosage ratio of the organic solvent to donepezil in the above preparation method may vary within a certain range, for example, 4 to 20 mL:1 g.

[0107] In one embodiment of the present invention, the dosage ratio of the organic solvent to donepezil in the above preparation method may be 6 to 15 mL:1 g.

[0108] In one embodiment of the present invention, the dispersion in the above preparation method can be completed by at least one of stirring and ultrasonic treatment.

[0109] In one embodiment of the present invention, the dispersion in the above preparation method can be completed by stirring.

[0110] In one embodiment of the present invention, the dispersion in the above preparation method can be completed by mechanical stirring.

[0111] In one embodiment of the present invention, the time of mechanical stirring in the above preparation method can vary within a certain range, such as 30 - 60 s.

[0112] In one embodiment of the present invention, the time of mechanical stirring in the above preparation method can be 30 s.

[0113] In one embodiment of the present invention, the rotation speed of mechanical stirring in the above preparation method can vary within a certain range, such as 250 - 350 rpm.

[0114] In one embodiment of the present invention, the rotation speed of mechanical stirring in the above preparation method can be 300 rpm.

[0115] In one embodiment of the present invention, the emulsification in the above preparation method can be completed by membrane emulsification.

[0116] In one embodiment of the present invention, the curing in the above preparation method can be completed by volatilization or evaporation.

[0117] In one embodiment of the present invention, the curing in the above preparation method can be completed by reduced-pressure volatilization, stirring volatilization or thin-film evaporation.

[0118] In one embodiment of the present invention, the curing in the above preparation method can be completed by reduced-pressure volatilization.

[0119] In one embodiment of the present invention, the vacuum degree of reduced-pressure volatilization in the above preparation method can vary within a certain range, such as -0.09 - -0.05 MPa.

[0120] In one embodiment of the present invention, the vacuum degree of reduced-pressure volatilization in the above preparation method can be -0.09 MPa.

[0121] In one embodiment of the present invention, the time of reduced-pressure volatilization in the above preparation method can vary within a certain range, such as 20 - 300 min.

[0122] In one embodiment of the present invention, the time of reduced-pressure volatilization in the above preparation method can be 20 - 240 min.

[0123] In one embodiment of the present invention, the reduced-pressure evaporation temperature in the above preparation method can vary within a certain range, for example, 20-42°C.

[0124] In one embodiment of the present invention, the reduced-pressure evaporation temperature in the above preparation method can be 38°C.

[0125] In one embodiment of the present invention, the above preparation method may further include the following steps: washing and freeze-drying after the emulsion is solidified.

[0126] Correspondingly, the present invention provides a sustained-release microsphere of donepezil, which is prepared by the above preparation method.

[0127] In one embodiment of the present invention, the particle size of the donepezil sustained-release microsphere prepared by the above preparation method can be 10-50 μm.

[0128] In one embodiment of the present invention, the particle size of the donepezil sustained-release microsphere prepared by the above preparation method can be 25-35 μm.

[0129] In one embodiment of the present invention, the encapsulation efficiency of the donepezil sustained-release microsphere prepared by the above preparation method can be more than 80%.

[0130] In one embodiment of the present invention, the encapsulation efficiency of the donepezil sustained-release microsphere prepared by the above preparation method can be more than 90%.

[0131] In one embodiment of the present invention, the drug loading of the donepezil sustained-release microsphere prepared by the above preparation method can be 20%-60%.

[0132] In one embodiment of the present invention, the drug loading of the donepezil sustained-release microsphere prepared by the above preparation method can be 40%-60%.

[0133] Pharmaceutical Preparations of Donepezil

[0134] The present invention provides a pharmaceutical preparation of donepezil, which comprises the above sustained-release microsphere.

[0135] In one embodiment of the present invention, the above pharmaceutical preparation may further comprise at least one pharmaceutically acceptable excipient, such as a solvent, a solubilizer, a cosolvent, etc.

[0136] In one embodiment of the present invention, the above pharmaceutical preparation can be a preparation with a specific drug release behavior, such as a sustained-release preparation.

[0137] In one embodiment of the present invention, the above pharmaceutical preparation can be a parenteral dosage form, such as an injection.

[0138] Medical Use of Donepezil Sustained Release Microspheres and Their Pharmaceutical Preparations

[0139] The present invention provides the use of the above-mentioned sustained-release microspheres or the above-mentioned pharmaceutical preparation in the preparation of a medicament for preventing and / or treating at least partially diseases and / or disorders related to acetylcholinesterase.

[0140] In one embodiment of the present invention, the at least partially diseases and / or disorders related to acetylcholinesterase may be Alzheimer's disease.

[0141] Method for Determining Parameters of Donepezil Sustained Release Microspheres

[0142] Using the particle size and particle size distribution measurement method, the particle size and span value (span value of particle size distribution, the smaller the span value, the more uniform the particle size of the microspheres) of the microspheres were measured as follows:

[0143] Take 50 mg of microspheres, add them to 20 mL of water, shake and sonicate for 10 min to disperse the microspheres evenly, then add them to the sample loading tank of the laser particle size analyzer to measure the particle size and calculate the span value. The calculation formula is as follows:

[0144]

[0145] where D V,90％ , D V,50％ and D V,10％ respectively represent the particle sizes of the microspheres corresponding to volume fractions of 90%, 50% and 10% respectively.

[0146] Using high performance liquid chromatography, the drug loading and encapsulation efficiency of the microspheres were detected as follows:

[0147] Drug loading detection method: Dissolve 25 mg of microspheres completely with 80% v / v acetonitrile, then dilute to 50 mL, take 1 mL and dilute to 10 mL, inject 20 μL of the diluted solution into HPLC (Welch Ultimate XB-C18, 150×4.6 mm, 5 μm), measure at a detection wavelength of 271 nm, and the mobile phase used is prepared by mixing phosphate buffer (pH 5.0) and acetonitrile in a ratio of 7:3.

[0148] Encapsulation efficiency detection method: Wash 25 mg of microspheres with PBS solution, dissolve the solid completely with 80% v / v acetonitrile, then dilute to 50 mL, take 1 mL and dilute to 10 mL, and the subsequent operations are the same as the drug loading detection method.

[0149] The calculation formulas for drug loading and encapsulation efficiency are as follows:

[0150]

[0151]

[0152] Example

[0153] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0154] Embodiment 1:

[0155] Weigh 1.5 g of donepezil and 1.0 g of PLGA (LA:GA=75:25, intrinsic viscosity of 0.4-0.5 dL / g), dissolve in 10 mL of dichloromethane to obtain O; prepare 100 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase, without pH adjustment, to obtain W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 seconds at a speed of 300 rpm. Pour the pre-emulsion into a rapid membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 20 μm. The emulsion is cured by vacuum-0.09 MPa for 60 minutes at 38°C. After the curing is completed, wash and freeze-dry to obtain the sustained-release microspheres containing donepezil.

[0156] The average particle size of the prepared sustained-release microspheres was measured by particle size and particle size distribution determination method, and the Span value was 1.2. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were measured by high performance liquid chromatography, and the drug loading was 49.5%, and the encapsulation efficiency was 82.5%.

[0157] pass Figure 1 It can be seen that the donepezil sustained-release microspheres of Example 1 are relatively broken, the particle sizes of the microspheres are different, and the surface of the microspheres is rough, mostly collapsed, and has a large number of tiny holes, and the drug escapes and precipitates to form small flakes or block crystals.

[0158] The prior art proposes that using an ice water bath when preparing a pre-emulsion can minimize drug escape, but the temperature will affect the viscosity of the dispersed phase and the continuous phase, the solubility of the surfactant, the phase transition temperature and the diffusion performance, and the interfacial tension of the two phases, thereby affecting the particle size and performance of the microspheres. The preparation of the present invention is not carried out at low temperature, and the obtained microspheres have uniform particle size and stable release.

[0159] Embodiment 2:

[0160] Weigh 1.5 g of donepezil and 1.0 g of PLGA (LA:GA=75:25, intrinsic viscosity of 0.4-0.5 dL / g), dissolve in 10 mL of dichloromethane to obtain O; prepare 100 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase, add 1.0 g of sodium chloride, and do not adjust the pH to obtain W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 seconds at a speed of 300 rpm. Pour the pre-emulsion into a rapid membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 20 μm. The emulsion is cured by vacuum-0.09 MPa for 60 minutes at 38°C. After the curing is completed, wash and freeze-dry to obtain sustained-release microspheres containing donepezil.

[0161] The average particle size of the prepared sustained-release microspheres was determined to be 12 μm using the particle size and particle size distribution determination method, and the span value was 1.0. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were determined using high performance liquid chromatography, and the drug loading was 51.1% and the encapsulation efficiency was 85.17%.

[0162] By comparison Figure 1 and Figure 2 It can be seen that in Example 2, a certain amount of osmotic pressure regulator is added to the aqueous phase. Although the donepezil sustained-release microspheres still have broken holes, most of them are collapsed, and drugs still escape and precipitate outside the microspheres to form small flakes or block-shaped flake crystals, the surface of the microspheres is relatively smooth and intact. This shows that the addition of an osmotic pressure regulator in the present invention can inhibit drug escape and make the surface of the microspheres smoother.

[0163] Embodiment 3:

[0164] Weigh 1.5 g of donepezil and 1.0 g of PLGA (LA:GA=75:25, intrinsic viscosity of 0.4-0.5 dL / g), dissolve in 10 mL of dichloromethane to obtain O; prepare 100 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase, and adjust its pH to 6.0 with sodium hydroxide to obtain W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 seconds at a speed of 300 rpm. Pour the pre-emulsion into a rapid membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 20 μm. The emulsion is cured by vacuum-0.09 MPa for 60 minutes at 38°C. After the curing is completed, wash and freeze-dry to obtain the sustained-release microspheres containing donepezil.

[0165] The average particle size of the prepared sustained-release microspheres was measured by particle size and particle size distribution determination method, and the Span value was 0.7. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were measured by high performance liquid chromatography, and the drug loading was 55.2% and the encapsulation efficiency was 92.0%.

[0166] By comparison Figure 3 and Figure 1 It can be seen that in Example 3, the pH is adjusted to 8.Figure 3 Although there are still many precipitated drug crystals in the donepezil sustained-release microspheres, the surface of the microspheres is relatively smooth and intact, without obvious surface damage or large holes. It shows that adding a pH regulator in the present invention can effectively improve the fragmentation of the microspheres and make the surface of the microspheres smoother.

[0167] Example 4:

[0168] Weigh 1.5 g of donepezil and 1.0 g of PLGA (LA:GA = 75:25, intrinsic viscosity is 0.4 - 0.5 dL / g), dissolve them in 10 mL of dichloromethane to prepare O; prepare 100 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase, and adjust its pH to 10.0 with sodium hydroxide to prepare W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a high-speed membrane emulsifier for emulsification and dispersion, and use a membrane tube with a pore size of 20 μm. The emulsion is cured at -0.09 MPa vacuum for 60 min at 38 °C. After curing, wash and freeze-dry to obtain donepezil sustained-release microspheres.

[0169] Use the particle size and particle size distribution measurement method to measure that the average particle size of the prepared sustained-release microspheres is 13 μm, and the Span value is 0.7. Use high-performance liquid chromatography to measure the drug loading and encapsulation efficiency of the prepared sustained-release microspheres. The drug loading is 57.5%, and the encapsulation efficiency is 95.8%.

[0170] By comparison Figure 1 、 Figure 3 and Figure 4 It can be seen that although there are still some crystals in the donepezil sustained-release microspheres of Example 4, the crystals are attached to the microspheres in the form of small strips or filaments, and do not escape in large quantities to form blocks or flakes, and there are no obvious surface damages or large holes. It shows that adding a pH regulator and maintaining a certain alkaline environment in the present invention can effectively reduce the escape of crystals and improve the phenomenon of surface damage or large holes of the microspheres.

[0171] Example 5:

[0172] Weigh 3.0 g of donepezil and 2.0 g of PLGA (LA:GA = 50:50, intrinsic viscosity is 0.6 - 0.7 dL / g), dissolve them in 20 mL of dichloromethane to prepare O; prepare 200 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase, and adjust its pH to 10.0 with sodium hydroxide to prepare W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a high-speed membrane emulsifier for emulsification and dispersion, and use a membrane tube with a pore size of 20 μm. The emulsion is cured at -0.09 MPa vacuum for 60 min at 38 °C. After curing, wash and freeze-dry to obtain donepezil sustained-release microspheres.

[0173] The average particle size of the prepared sustained-release microspheres was determined to be 14 μm and the Span value was 0.7 by using the particle size and particle size distribution measurement method. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were determined by using high performance liquid chromatography. The drug loading was 56.2% and the encapsulation efficiency was 93.4%.

[0174] By Figure 5 It can be seen that there are some small flaky crystals outside the donepezil sustained-release microspheres of Example 5, and the surface of the microspheres is relatively smooth, complete and without damage.

[0175] Example 6:

[0176] Weigh 6 g of donepezil and 4 g of PLGA (LA:GA = 50:50, intrinsic viscosity 0.6 - 0.7 dL / g), dissolve them in 40 mL of dichloromethane to prepare O; prepare 400 mL of 1.0% aqueous polyvinyl alcohol solution as the external aqueous phase, add 1.9 g of sodium chloride, and adjust its pH to 10.0 with sodium hydroxide to obtain W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a high-speed membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 20 μm. The emulsion is cured at -0.09 MPa for 60 min at 38 °C. After curing, wash and freeze-dry to obtain the donepezil sustained-release microspheres.

[0177] The average particle size of the prepared sustained-release microspheres was determined to be 14 μm and the Span value was 0.5 by using the particle size and particle size distribution measurement method. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were determined by using high performance liquid chromatography. The drug loading was 59.9% and the encapsulation efficiency was 99.8%.

[0178] By comparison Figure 5 and Figure 6 It can be seen that the surface of the donepezil sustained-release microspheres of Example 6 is relatively smooth and complete, there are basically no depressions or cavities, the particle size uniformity is good, and at the same time, the phenomenon of microsphere escape outside the microspheres is significantly improved. When the theoretical drug loading is 60%, compared with Example 5, it shows that adding both a pH regulator and an osmotic pressure regulator can not only significantly reduce crystal escape, but also the surface of the microspheres is smooth and there are almost no damaged holes.

[0179] Example 7:

[0180] Weigh 2.8 g of donepezil and 4 g of PLGA (LA:GA = 75:25, intrinsic viscosity 0.6 - 0.7 dL / g), dissolve them in 40 mL of dichloromethane to obtain O; prepare 400 mL of 1.0% aqueous polyvinyl alcohol solution as the external aqueous phase, add 1.5 g of sodium chloride, and adjust its pH to 10.0 with sodium hydroxide to obtain W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a high-speed membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 20 μm. The emulsion is cured at -0.09 MPa under vacuum for 60 min at 38 °C. After curing, wash and freeze-dry to obtain donepezil sustained-release microspheres.

[0181] The average particle size of the prepared sustained-release microspheres was measured to be 12 μm and the Span value was 0.6 using the particle size and particle size distribution measurement method. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were measured by high performance liquid chromatography, with the drug loading being 40.1% and the encapsulation efficiency being 97.8%.

[0182] By comparison Figure 6 and Figure 7 It can be seen that the surface of the donepezil sustained-release microspheres in Example 7 is relatively smooth and complete, without depressions or cavities, and there are a small number of microspheres with uneven particle sizes. It shows that no drug escape is observed in the donepezil microspheres prepared after reducing the drug loading.

[0183] Example 8:

[0184] Weigh 2.8 g of donepezil and 4 g of PLGA (LA:GA = 75:25, intrinsic viscosity 0.6 - 0.7 dL / g), dissolve them in 40 mL of dichloromethane to obtain O; prepare 400 mL of 1.0% aqueous polyvinyl alcohol solution as the external aqueous phase, add 1.5 g of sodium chloride, and adjust its pH to 10.0 with sodium hydroxide to obtain W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a high-speed membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 50 μm. The emulsion is cured at -0.09 MPa under vacuum for 60 min at 38 °C. After curing, wash and freeze-dry to obtain donepezil sustained-release microspheres.

[0185] The average particle size of the prepared sustained-release microspheres was measured to be 28 μm and the Span value was 0.6 using the particle size and particle size distribution measurement method. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were measured by high performance liquid chromatography, with the drug loading being 40.9% and the encapsulation efficiency being 99.8%.

[0186] By comparison Figure 7 and Figure 8It can be seen that the surface of the donepezil sustained-release microspheres in Example 8 is relatively smooth and intact, without depressions or cavities, and the particle size is relatively uniform, indicating that in the present invention, appropriately expanding the membrane pore size during membrane emulsification has no significant effect on the particle size distribution of the microspheres.

[0187] Comparative Example 1:

[0188] Weigh 1.0 g of donepezil and 1.0 g of PLGA (LA:GA = 50:50, intrinsic viscosity 0.2 - 0.3 dL / g), dissolve them in 10 mL of dichloromethane to prepare O; prepare 100 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase without pH adjustment to prepare W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a rapid membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 20 μm. The emulsion is cured at -0.09 MPa vacuum for 60 min at 38°C. After curing, wash and freeze-dry to obtain donepezil sustained-release microspheres.

[0189] Use the particle size and particle size distribution measurement method to measure the average particle size of the prepared sustained-release microspheres to be 13 μm, and the Span value is 1.5. Use high-performance liquid chromatography to measure the drug loading and encapsulation efficiency of the prepared sustained-release microspheres. The drug loading is 38.1%, and the encapsulation efficiency is 76.2%.

[0190] By comparison Figure 2 、 Figure 3 、 Figure 6 and Figure 9 It can be seen that the donepezil sustained-release microspheres prepared in Comparative Example 1 are more broken, the particle sizes of the microspheres are uneven, and the surface of the microspheres is rough, with many collapses and a large number of small holes. The drug escapes and precipitates to form small flakes or blocks of crystals. It shows that adding a pH regulator and an osmotic pressure regulator in the present invention has a significant impact on drug escape, the surface of the microspheres, and the drug loading.

[0191] Comparative Example 2:

[0192] Weigh 1.0 g of donepezil and 1.0 g of PLGA (LA:GA = 50:50, intrinsic viscosity 0.2 - 0.3 dL / g), dissolve them in 10 mL of dichloromethane to prepare O; prepare 100 mL of 1.0% polyvinyl alcohol aqueous solution as the external aqueous phase, add 1.0 g of sodium chloride, and adjust its pH to 10.0 with sodium hydroxide to prepare W. Add O to W and prepare a pre-emulsion by mechanical stirring for 30 s at a rotation speed of 300 rpm. Pour the pre-emulsion into a rapid membrane emulsifier for emulsification and dispersion, using a membrane tube with a pore size of 50 μm. The emulsion is cured at -0.09 MPa vacuum for 60 min at 45°C. After curing, wash and freeze-dry to obtain donepezil sustained-release microspheres.

[0193] The average particle size of the prepared sustained-release microspheres was determined to be 13 μm and the Span value was 1.8 using the particle size and particle size distribution measurement method. The drug loading and encapsulation efficiency of the prepared sustained-release microspheres were determined by high performance liquid chromatography. The drug loading was 24.2% and the encapsulation efficiency was 48.4%.

[0194] By comparing Figure 6 and Figure 10 it can be seen that the donepezil microspheres of Comparative Example 2 showed obvious fragmentation and surface collapse, the particle size of the microspheres was uneven, and drug escape and precipitation formed small flakes or lumps of crystals. It is shown that when the decompression volatilization temperature of the microspheres is relatively high, the carrier material degrades due to high temperature, resulting in fragmentation and collapse of the microspheres, and ultimately leading to ineffective drug entrapment and low drug loading.

[0195] Example 11: In vitro cumulative release experiment

[0196] 10 mg of the microspheres in Example 1, Example 5, Example 6, Example 7, and Example 8 and PBS buffer (pH 7.4) were respectively placed in a 250 mL conical flask and constantly shaken at 37 °C on a water bath shaker. According to the sampling time, 1 mL of the solution was taken from the conical flask and the same amount of PBS buffer was added. The collected solution was filtered through a 0.45 μm syringe filter, and 10 μL of the above solution was detected by HPLC. The in vitro cumulative release curves of the microspheres prepared in the five groups of examples are as Figure 11 shown.

[0197] By Figure 11 it can be seen that the present invention can effectively reduce drug escape and avoid drug precipitation and crystallization by controlling the pH of the aqueous phase and adjusting the osmotic pressure, thereby effectively reducing the initial burst release of the drug; by increasing the particle size of the microspheres and appropriately reducing the drug loading, the initial burst release of the drug can be effectively reduced and the release period can be prolonged. The donepezil sustained-release microspheres prepared by the present invention have the ability of long-term and stable release.

[0198] It should be noted that although the technical solutions of the present invention are introduced by specific examples, those skilled in the art can understand that the present invention should not be limited thereto.

[0199] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skilled persons in the technical field to understand the embodiments disclosed herein.

Claims

1. A preparation method of donepezil sustained-release microspheres, characterized in that, The preparation method comprises the following steps: Mix a surfactant, an osmotic pressure regulator and water, and adjust the pH value of the mixture using a pH regulator to form an aqueous phase; Mix donepezil, a carrier material and an organic solvent to form an oil phase; and, Add the oil phase to the aqueous phase for dispersion to form a pre-emulsion, then subject the pre-emulsion to membrane emulsification to form an emulsion, and finally solidify the emulsion, wash and lyophilize to obtain donepezil sustained-release microspheres.

2. The preparation method according to claim 1, wherein The pre-emulsion is an oil-in-water pre-emulsion.

3. The preparation method according to claim 1 or 2, wherein The surfactant is at least one of polyvinyl alcohol, Tween, sodium dodecyl sulfate, sodium dodecylbenzenesulfonate and polyoxyethylene octylphenol ether, preferably polyvinyl alcohol; and / or, the weight ratio of the surfactant to donepezil is 1:5 to 20:5, preferably 4:5 to 8:5; and / or, The osmotic pressure regulator is at least one of sodium chloride and potassium chloride, preferably sodium chloride; and / or, the weight ratio of the osmotic pressure regulator to donepezil is 1:5 to 6:5, preferably 1.5:5 to 4:5; and / or, The water is at least one of ultrapure water, double-distilled water and water for injection, preferably ultrapure water; and / or, the volume ratio of the water to the organic solvent is 5:1 to 50:1, preferably 8:1 to 14:1; and / or, The pH regulator is at least one of hydrogen chloride and sodium hydroxide; and / or, the pH regulator adjusts the pH value of the mixture to 6.0 to 12.0, preferably 6.0 to 10.

0.

4. The preparation method according to any one of claims 1 to 3, wherein The carrier material is a biodegradable carrier material; preferably, the carrier material is at least one of poly(lactic-co-glycolic acid), poly(lactic acid)-poly(ethylene glycol) copolymer and poly(lactic acid), preferably poly(lactic-co-glycolic acid), more preferably, the intrinsic viscosity of the carrier material is 0.15 dL / g to 0.90 dL / g, preferably 0.4 dL / g to 0.7 dL / g; and / or, the weight ratio of the carrier material to donepezil is 2:3 to 12:3, preferably 2:3 to 5:3; and / or, The organic solvent is at least one of chloroform, dichloromethane, ethyl acetate, acetone, acetonitrile, absolute ethanol, preferably dichloromethane; and / or, the dosage ratio of the organic solvent to donepezil is 4 to 20 mL:1 g, preferably 6 to 15 mL:1 g.

5. The preparation method according to any one of claims 1 to 4, wherein The dispersion is completed by at least one of stirring and ultrasonic treatment, preferably stirring, more preferably mechanical stirring; preferably, the time of the mechanical stirring is 30 to 60 s; and / or, the rotation speed of the mechanical stirring is 250 to 350 rpm; and / or, The emulsification is completed by membrane emulsification; and / or, The curing is completed by volatilization or evaporation, preferably by reduced-pressure volatilization, stirring volatilization or thin-film evaporation, more preferably by reduced-pressure volatilization; preferably, the degree of vacuum for the reduced-pressure volatilization is -0.09 to -0.05 MPa; and / or, the time for the reduced-pressure volatilization is 20 to 300 min; the temperature for the reduced-pressure volatilization is 20 to 42 °C.

6. The preparation method according to any one of claims 1 to 5, characterized in that the preparation method further comprises the following steps: washing and freeze-drying the cured emulsion.

7. The preparation method according to any one of claims 1 to 6, characterized in that the particle size of the donepezil sustained-release microspheres is 10 to 50 μm, preferably 25 to 35 μm; and / or, the encapsulation efficiency of the donepezil sustained-release microspheres is more than 80%, preferably more than 90%; and / or, the drug loading of the donepezil sustained-release microspheres is 20% to 60%, preferably 40% to 60%.

8. A donepezil sustained-release microsphere, characterized in that, The sustained-release microspheres are prepared by the preparation method according to any one of claims 1 to 6.

9. A pharmaceutical preparation of donepezil, characterized in that, The pharmaceutical preparation comprises the sustained-release microspheres according to claim 8; preferably, the pharmaceutical preparation further comprises at least one pharmaceutically acceptable excipient; and / or, preferably, the pharmaceutical preparation is a sustained-release preparation; and / or, preferably, the pharmaceutical preparation is an injection.

10. Use of the sustained-release microspheres according to claim 8 or the pharmaceutical preparation according to claim 9 in the preparation of a drug for preventing and / or treating at least partially diseases and / or disorders related to acetylcholinesterase; preferably, the at least partially diseases and / or disorders related to acetylcholinesterase are Alzheimer's disease.

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