KR20240000404A - Sustained release microsphere comprising donepezil and pamoic acid - Google Patents

Abstract

Sustained-release microspheres containing donepezil or a pharmaceutically acceptable salt thereof, pamoic acid, and a biocompatible polymer, pharmaceutical compositions for preventing, improving, or treating Alzheimer's disease or cognitive dysfunction containing such sustained-release microspheres, and said sustained-release microspheres A method for producing amorphous microspheres is provided.

Description

Sustained release microsphere comprising donepezil and pamoic acid}

The present invention relates to a long-acting microsphere injection containing donepezil and pamoic acid and a method for producing the same.

Acetylcholine is a neurotransmitter synthesized from choline and acetyl-CoA in cholinergic neurons. When the concentration of acetylcholine decreases, cognitive and perceptual abilities may be lost, and this is closely related to Alzheimer's.

Donepezil is widely used as a dementia treatment to suppress this decrease in acetylcholine concentration. Donepezil is a cholinesterase inhibitor that suppresses the decline in acetylcholine that occurs in dementia patients caused by Alzheimer's disease and raises the concentration of acetylcholine to the normal range.

Currently, donepezil is mostly administered orally once a day in tablet form. However, it must be taken consistently for more than a month to show clinical efficacy, and since Alzheimer's disease is a disease that mainly affects the elderly, taking it as an oral medication has limitations. Therefore, the demand for sustained-release preparations of anti-dementia drugs is continuously increasing.

Conventionally, microsphere preparations using biocompatible polymers to develop sustained-release preparations have developed into a field of active research interest and clinical application. However, in order to manufacture a microsphere preparation for long-term continuous administration, the drug to be contained in the microspheres must be included in a fairly high amount considering the administration period and dosage. For example, in the case of Aricept® tablets, an oral formulation of donepezil, the daily dosages are 5 mg, 10 mg, and 23 mg, respectively. When applying this as a sustained-release treatment that lasts for 1 month, a single drug dose of 140 mg to 280 mg or more may be required. On the other hand, when developing a sustained-release microsphere injection, it is difficult to administer at a time if the human dose of microspheres containing drugs and polymers is more than 1 g. Therefore, microspheres are easy to administer when administered in an amount of 1 g or less. In order to reduce the amount of administered microspheres, it is desirable to increase the drug content in the microspheres. In this way, when a high content of a drug is included in the microspheres, even if a biocompatible polymer with a sufficiently long decomposition rate is applied, the release period is not long enough due to the high content of the drug, so the desired administration period cannot be met, or the initial This can cause an 'initial burst' problem in which excessively rapid drug release occurs, and in this case, serious side effects may occur due to a rapid increase in blood concentration of the drug. On the other hand, when the content of the drug contained in the microspheres is lowered to solve this problem, the amount of the drug administered at a time is relatively excessively increased because the drug content for treatment is not sufficient, thereby reducing the patient's medication compliance. ) and there is a problem that it may cause discomfort.

Therefore, there is a need for the development of a donepezil sustained-release microsphere injection containing a high content of donepezil and having stable drug release characteristics for a long period of time.

The present invention was designed to solve the above-described conventional problems, and provides a donepezil sustained-release microsphere preparation that provides stable drug release characteristics for a long period of time despite encapsulating a high content of donepezil in the microspheres, and a method of manufacturing the same. The purpose is to provide

In one aspect of the present invention, the active ingredient is donepezil or a pharmaceutically acceptable salt thereof; Sustained-release microspheres manufactured using pamoic acid and biocompatible polymers,

The molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than 1:0.25 based on the form of donepezil free base, and the microspheres are donepezil free base, which has the characteristic of a cumulative release of less than 30% over 7 days. Microspheres may be provided.

In one aspect of the present invention, the active ingredient is donepezil or a pharmaceutically acceptable salt thereof; Sustained-release microspheres containing pamoic acid and biocompatible polymers,

The molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of donepezil,

The microspheres may provide sustained-release microspheres, which are donepezil and have the characteristic of having a cumulative release amount of less than 30% over 7 days.

In one aspect of the present invention, the donepezil and the pamoate may be in amorphous form.

In one aspect of the present invention, the content of donepezil in the microspheres, based on the free base form, may be 75% by weight or less based on the total weight of the microspheres.

In one aspect of the present invention, the content of the biocompatible polymer may be 20 to 50% by weight based on the total weight of the microspheres.

In one aspect of the present invention, the content of pamoic acid may be 2.5 to 20% by weight based on the total weight of the microspheres.

In one aspect of the present invention, the daily release amount of the active ingredient may be less than 10%.

In one aspect of the present invention, the AUC of microspheres released in vivo in one day may be less than 4%.

In one aspect of the present invention, the drug in the sustained-release microspheres may be released for 1 to 6 months.

In one aspect of the present invention, the sustained-release microspheres may have an average particle diameter (Dv50) of 10 μm or more.

In one aspect of the present invention, the microspheres may be for injection.

In one aspect of the present invention, a pharmaceutical composition containing sustained-release microspheres for preventing, improving, or treating Alzheimer's disease or cognitive dysfunction can be provided.

In one aspect of the present invention, a method for producing the sustained-release microspheres can be provided.

One aspect of the present invention provides sustained-release microspheres containing donepezil at a molar ratio of pamoic acid to donepezil of 0.05 to 0.25 and a content of 75% by weight or less, an injection containing the microspheres, and a method for producing the same.

In addition, the microspheres provide an injection containing sustained-release microspheres capable of sustained release for 1 to 6 months with an initial release of less than 10% per day and less than 30% of the particles per day, and a method for producing the same.

The donepezil sustained-release microsphere formulation according to the present invention can maintain the concentration of the drug in the therapeutic range for a long time without excessive initial release of the drug, thereby increasing the medication compliance of Alzheimer's patients and maximizing the treatment effect.

Figure 1 is a graph showing the cumulative release rate on day 7 according to the amount of pamoic acid added to donepezil sustained-release microspheres.
Figure 2 is an X-ray diffraction graph of microspheres containing donepezil and pamoic acid. Figure 3 shows blood drug levels up to 91 days after intramuscular or subcutaneous administration of donepezil sustained-release microspheres to animals in Comparative Example 3, Example 9 (intramuscular), Example 10 (intramuscular), and Example 10 (subcutaneous). This is a graph confirming the concentration.

Hereinafter, the present invention will be described in more detail.

In one aspect, the present invention,

As an active ingredient, donepezil or a pharmaceutically acceptable salt thereof; Sustained-release microspheres manufactured using pamoic acid and biocompatible polymers,

The molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of donepezil,

The microspheres are donepezil and are sustained-release microspheres that have the characteristic of having a cumulative release amount of less than 30% over 7 days.

In another aspect, the present invention,

As an active ingredient, donepezil or a pharmaceutically acceptable salt thereof; Sustained-release microspheres containing pamoic acid and biocompatible polymers,

The molar ratio of donepezil:pamoic acid may be greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of donepezil.

The microspheres are donepezil and are sustained-release microspheres that have the characteristic of having a cumulative release amount of less than 30% over 7 days.

Conventionally, microsphere preparations using biocompatible polymers to develop sustained-release preparations have developed into a field of active research interest and clinical application. However, in order to manufacture a microsphere preparation for long-term continuous administration, the drug to be contained in the microspheres must be contained in a fairly high amount considering the administration period and dosage. In this way, when a high content of a drug is included in the microspheres, even if a biocompatible polymer with a sufficiently long decomposition rate is applied, the release period is not long enough due to the high content of the drug, so the desired administration period cannot be met, or the release period is not long enough. An 'initial burst' problem may occur where drug release occurs too quickly in the beginning, and in this case, various side effects may occur due to a rapid increase in blood concentration of the drug. This is especially a serious problem for drugs with a low therapeutic index. It may happen. On the other hand, when the content of the drug contained in the microspheres is lowered to solve this problem, the amount of the drug administered at a time is relatively excessively increased because the drug content for treatment is not sufficient, thereby reducing the patient's medication compliance. ) and there is a problem that it may cause discomfort.

Accordingly, the present inventors confirmed that adding pamoic acid together with a drug when manufacturing microspheres can solve the problems of initial rapid release and the drug not being released for a sufficient period of time even if it contains a large amount of drug. However, when pamoic acid is used to manufacture microspheres, unexpectedly, when pamoic acid is used together with donepezil in the above content ratio, problems such as initial rapid release and the drug not being released for a sufficient period of time occur even if a large amount of the drug is included. It was confirmed that it could be resolved.

Specifically, in the present invention, the molar ratio of donepezil: pamoic acid as an active ingredient is greater than 1:0.05 and 1:0.25 or less, based on the donepezil free base form (i.e., molar ratio of donepezil free base: pamoic acid), preferably 1:0.05 to 1:0.2, 1:0.05 to 1:0.19, 1:0.07 to 1:0.22, 1:0.08 to 1:0.20, 1:0.09 to 1:0.19, 1:0.1 to 1:0.25, It may be 1:0.125 to 1:0.25.

In another embodiment, the pamoic acid in the sustained-release microspheres according to the present invention may be included in an amount of 2.5 to 20% by weight, 2.5 to 17% by weight, 2.5 to 15% by weight, or 2.5 to 13% by weight relative to the total weight of the microspheres. It is not limited.

The biocompatible polymer may be included in an amount of 20 to 50% by weight or 24 to 50% by weight based on the total weight of microspheres, but is not limited thereto.

The biocompatible polymers include poly(lactide-co-glycolide), poly(lactide-co-glycolide)glucose, polylactide, polyglycolide, polycaprolactone, and mixtures thereof; And it may be at least one selected from the group consisting of polyglycolide, polylactide, and polyglycolide and polylactide copolymer, but is not limited thereto.

Polylactide may be preferably used as the biocompatible polymer. Additionally, two or more polymers can be blended and used. As an example, it can be produced by blending polylactide and poly(lactide-co-glycolide). In this case, it is preferable that polylactide is included in an amount of 50% by weight or more compared to the total polymer weight.

In a preferred embodiment, in the case of a copolymer of polyglycolide and polylactide, the molar ratio of lactide to glycolide in the copolymer is 40:60 to 90:10, 45:55 to 85:15, or 50:50 to 75. :25, for example 45:55, 50:50, 75:25, or 85:15.

These biocompatible polymers may have a weight average molecular weight of 4,000 to 240,000. For example, the weight average molecular weight of the biocompatible polymer is 4,000 to 100,000, 7,000 to 50,000, 5,000 to 20,000, 10,000 to 18,000, and 18,000 to 28,000. Includes all lower numerical ranges within the above range, such as average molecular weight.

When two or more types of biocompatible polymers are included, the types of polymers exemplified above may be a combination or blend of different polymers, but the same type of polymers may be composed of polymers having different intrinsic viscosity and/or monomer ratios. A combination (e.g. a combination or blend of two or more poly(lactide-co-glycolides) with different intrinsic viscosity), or the same type of polymer with different end groups (e.g. an ester end group or an acid end group) Examples of commercially available biocompatible polymers that can be used in the present invention include RG 502H, RG 503H, RG 504H, RG 502, RG 503, RG 504 from the Resomer series of Evonik Rohm GmbH, RG 653H, RG 752H, RG 753H, RG 752S, RG 755S, RG 756S, RG 858S, R 202H, R 203H, R 205H, R 202S, R 203S, R 205S, Cobion's PDL 02, PDL 04, PDL 05 , PDL 06, PDLG 7502A, PDLG 7502, PDLG 7507, PDLG 5002A, PDLG 5002, PDLG 5004A, PDLG 5004, PDLG 5010, PL 10, PL 18, PL 24, PL 32, PL 38, PDL 20, PDL 45, PC 02, PC 04, PC 12, PC 17, and PC 24 alone or in combination or blend, but are not limited thereto.

Polylactide may be preferably used as the biocompatible polymer. Preferably, the intrinsic viscosity of the polylactide may be 0.25 dL/g to 2.0 dL/g, 0.25 dL/g to 1.7 dL/g, or 0.25 dL/g to 1.5 dL/g. If the intrinsic viscosity of polylactide is low (less than 0.25 dL/g), there is a problem in which the active ingredient is not well encapsulated within the microspheres. If the viscosity is more than 1.5 dL/g, the manufacturing yield of the microspheres is lowered, making it less economical. There is a problem with it falling.

The intrinsic viscosity of polylactide used in the present invention is measured at a concentration of 0.1% (w/v) in chloroform at 25°C using an Ubbelohde viscometer.

Additionally, two or more polymers can be blended and used. As an example, it can be produced by blending polylactide and poly(lactide-co-glycolide). In this case, it is preferable that polylactide is contained at least 50%.

The sustained-release microspheres may additionally contain donepezil pamoate.

In one embodiment, the sustained-release microspheres according to the present invention may include donepezil, a pamoate form of donepezil, and/or pamoic acid.

In one embodiment, the donepezil pamoate may be in an amorphous form.

In one embodiment, the donepezil may be donepezil free base.

In one embodiment, based on the free base form, the content of donepezil is 75% by weight or less, 40 to 75% by weight, 40 to 70% by weight, 40 to 65% by weight, 45 to 75% by weight, 45% by weight, based on the total weight of the microspheres. It may be from 70% by weight, 45 to 65% by weight, 45 to 60% by weight, 50 to 75% by weight, 50 to 70% by weight, 50 to 65% by weight, or 50 to 60% by weight, but is not limited thereto.

If the above range is met, it has the advantage of being able to maintain an appropriate release rate during the release period in which the release of the drug is not rapid or excessively delayed.

It is preferable that the microspheres of the present invention have uniform particle distribution. Microspheres with uniform particle distribution have less variation during injection and can be administered in a more accurate amount compared to non-uniform microspheres.

It is preferable that the span value of the microspheres of the present invention is 1.2 or less.

The term “Span value” used in the present invention is an indicator of the uniformity of the particle size of microspheres, and the span value means the value obtained by Equation 1 below.

[Equation 1]

Span Value = (Dv0.9 - Dv0.1)/Dv0.5

Here, Dv0.1 is the particle size corresponding to 10% of the volume % in the particle size distribution curve of the microspheres, Dv0.5 is the particle size corresponding to 50% of the volume % in the particle size distribution curve of the microspheres, and Dv0.9 is the particle size distribution of the microspheres. It refers to the particle size corresponding to 90% of the volume% in the curve.

In a specific embodiment, the average particle diameter (Dv50) of the microspheres according to the present invention is 10 um or more, preferably 15 um or more, 20 um or more, 30 um or more, 150 um or less, 120 um or less, 100 um or less, 90 um or less, 80 um. Hereinafter, it may be 70 um or less, 10 to 150 um, 10 to 120 um, 10 to 100 um, 10 to 90 um, 15 to 90 um, 15 to 80 um, 20 to 90 um, 20 to 80 um, 30 to 80 um, or 30 to 70 um.

According to the present invention, the drug in microspheres may have an initial daily release rate of less than 10%. Preferably, the initial release rate may be, but is not limited to, less than 9%, less than 8%, or less than 7%.

According to the present invention, the AUC for one-day release of microspheres in vivo may be less than 4% of the total AUC. Preferably, the AUC upon daily release may be less than 4%, less than 3%, more than 0.01%, more than 0.3%, or more than 0.5%, but is not limited thereto.

In a specific embodiment, donepezil or a pharmaceutically acceptable salt thereof in sustained-release microspheres according to the present invention may be released for 1 to 6 months.

In a specific embodiment, the sustained-release microspheres according to the present invention may be for injection.

In another aspect, the present invention relates to a pharmaceutical composition for preventing, improving or treating Alzheimer's disease or cognitive dysfunction, comprising the sustained-release microspheres. More specifically, the pharmaceutical composition may further include a pharmaceutically acceptable carrier. Preferably, the pharmaceutical composition may be an injectable formulation.

Hereinafter, the method for producing sustained-release microspheres of the present invention will be described in detail.

Sustained-release microspheres according to the present invention may be produced using, for example, a “solvent extraction and evaporation method,” but the production method is not limited thereto.

As a specific example of the method for producing sustained-release microspheres according to the present invention, a method for producing sustained-release microspheres is provided comprising the following steps:

(a) donepezil or a pharmaceutically acceptable salt thereof as an active ingredient; Preparing a dispersed phase by dissolving pamoic acid and a biocompatible polymer in a solvent for the dispersed phase;

(b) preparing an emulsion by adding the dispersed phase prepared in step (a) to an aqueous solution containing a surfactant as a continuous phase;

(c) extracting the solvent for the dispersed phase in the dispersed phase of the emulsion prepared in step (b) into a continuous phase and evaporating the extracted solvent to form microspheres to prepare a suspension containing microspheres; and

(d) recovering the microspheres from the suspension of step (c) to prepare microspheres,

The molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of donepezil.

In the above manufacturing method, unless otherwise specified, matters regarding donepezil or a pharmaceutically acceptable salt thereof, pamoic acid, and biocompatible polymers can be applied as described for the microspheres.

In one specific embodiment, the content of the active ingredient may be 75% by weight or less based on the total weight of the microspheres.

In a specific embodiment, the content of the biocompatible polymer may be 20 to 50% by weight based on the total weight of the microspheres.

In a specific embodiment, the content of pamoic acid may be 2.5 to 20% by weight based on the total weight of the microspheres.

Additionally, in one specific embodiment, in step (a), the active ingredient is in free base form, and pamoic acid may be included in the form of powder or solution.

As a specific embodiment, step (a) may be performed by adding pamoic acid to a solution of the active ingredient dissolved in the solvent for the dispersion phase.

The solvent for the dispersed phase is preferably immiscible with water in an amount of at least 50% (w/w) compared to the total mixed solvent, but is not limited thereto.

There is no limitation to the solvent for this dispersion phase, but dichloromethane, ethyl acetate, ethyl formate, methyl acetate, methyl formate, butyl acetate, n-propyl acetate, isopropyl acetate, n-propyl formate, glycofurol, methyl isopropyl. It may contain ketone, dimethyl carbonate, or a mixed solvent thereof.

In addition, the solvent for the dispersion phase is selected from the group consisting of chloroform, acetone, acetonitrile, dimethyl sulfoxide, dimethyl formamide, methyl ethyl ketone, acetic acid, methyl alcohol, ethyl alcohol, propyl alcohol, benzyl alcohol, and mixed solvents thereof. One or more types may be additionally included.

The method of homogeneously mixing the dispersed phase and the continuous phase containing the surfactant in step (b) is not particularly limited, but can be performed using a high-speed stirrer, in-line mixer, membrane emulsion method, microfluidics emulsion method, etc. . When forming an emulsion using a high-speed stirrer or in-line mixer, it is difficult to obtain a uniform emulsion, so it is desirable to perform an additional sieving process between steps (c) and (d), which will be described later. It is more preferable to use the membrane emulsion method and the microfluidics emulsion method because an emulsion of uniform size can be obtained and no additional sieving process is required between steps (c) and (d), which will be described later.

The type of surfactant used in step (b) is not particularly limited, and any dispersed phase can be used as long as it can help form a stable liquid droplet dispersed phase within the continuous phase. The surfactant is preferably a group consisting of methylcellulose, polyvinylpyrrolidone, carboxymethylcellulose, lecithin, gelatin, polyvinyl alcohol, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene castor oil derivative, and mixtures thereof. It can be selected from, and most preferably polyvinyl alcohol can be used.

In step (b), the content of the surfactant in the continuous phase containing the surfactant is 0.01 w/v% to 20 w/v%, preferably 0.1 w/v, based on the total volume of the continuous phase containing the surfactant. It may be v% to 5 w/v%. If the surfactant content is less than 0.01 w/v%, a dispersed phase or emulsion in the form of droplets may not be formed in the continuous phase, and if the surfactant content exceeds 20 w/v%, an excessive amount of surfactant may be present. Because of this, it may be difficult to remove the surfactant after fine particles are formed in the continuous phase.

The continuous phase used in step (b) can be water, and in order to control the extraction rate of the organic solvent from the dispersed phase in the emulsion state, methyl alcohol, ethyl alcohol, propyl alcohol, ethyl formate, methyl acetate, methyl formate, Water containing some of one or more selected from the group consisting of butyl acetate, n-propyl acetate, isopropyl acetate, n-propyl formate, glycofurol, methyl isopropyl ketone, dimethyl carbonate, and ethyl acetate can be used. .

The continuous phase may be used in an amount of 5,000 (v/w)% to 100,000 (v/v)% compared to the dispersed phase solvent, but is not limited thereto.

In step (c), the emulsion comprising a dispersed phase in the form of droplets and a continuous phase containing a surfactant is maintained or stirred at a temperature below the boiling point of the organic solvent for a certain period of time, for example, 2 to 48 hours, The organic solvent can be extracted from the dispersed phase in the form of droplets into the continuous phase. Some of the organic solvent extracted in the continuous phase may evaporate from the surface. As the organic solvent is extracted from the droplet-shaped dispersed phase, the droplet-shaped dispersed phase may solidify to form microspheres.

In order to additionally and efficiently remove the organic solvent in step (c), heat may be applied to the temperature of the continuous phase for a certain period of time.

In step (d), the method of recovering microspheres according to the present invention may be performed using various known techniques, for example, methods such as filtration or centrifugation may be used.

Between steps (c) and (d), the remaining surfactant can be removed through filtration and washing, and the microspheres can be recovered by filtering again.

The washing step to remove the remaining surfactant can typically be performed using water, and the washing step can be repeated several times.

In addition, as described above, when an emulsion is formed using a high-speed stirrer and an in-line mixer in step (b), uniform microspheres can be obtained by additionally using a sieving process between steps (c) and (d). You can. The sieving process can be performed using known techniques, and microspheres of uniform size can be obtained by filtering out microspheres of small and large particles using sieve membranes of different sizes.

In the production method of the present invention, after step (d) or after the filtration and washing steps, the obtained microspheres are dried using a conventional drying method to obtain finally dried microspheres.

Hereinafter, preferred embodiments are presented to aid understanding of the present invention. However, the following examples are merely illustrative of the present invention, and it is clear to those skilled in the art that various changes and modifications are possible within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the attached patent claims.

[Example]

Hereinafter, the present invention will be described in more detail through examples. Since these examples are merely for illustrating the present invention, the scope of the present invention is not to be construed as limited by these examples.

Comparative Example 1. Preparation of donepezil microspheres without added pamoic acid

The dispersed phase is transparent to the naked eye by mixing 3.0 g of biocompatible polymer Purasorb PDL02A (manufacturer: Corbion, Netherlands) and 2.0 g of donepezil base (manufacturer: Neuland Laboratories, India) with 9.0 g of dichloromethane (manufacturer: J.T Baker, USA). It was used after sufficiently dissolving until it dissolved. A 0.1% polyvinyl alcohol (viscosity: 4.8~5.8 mPa·s) aqueous solution was used as the continuous phase, and 3,000 mL of the continuous phase was connected to an emulsification device equipped with a porous membrane with a diameter of 40 μm, and the prepared dispersed phase was injected to prepare microspheres. The microsphere suspension was placed in a preparation container and stirred at a speed of 200 rpm.

The temperature of the membrane emulsifier and the preparation vessel was maintained at 25°C, and after the injection of the dispersed phase was completed, the suspension in the preparation vessel was stirred at a speed of 200 rpm and maintained at a temperature of 25°C for 60 minutes. Afterwards, the organic solvent was removed while maintaining the temperature at 45°C for 3 hours. After removal of the organic solvent, the temperature of the microparticle suspension was lowered to 25°C. The microsphere suspension was washed several times with ultrapure water to remove residual polyvinyl alcohol, and the microspheres were freeze-dried.

Comparative Example 2-6. Preparation of donepezil microspheres with different proportions of pamoic acid

The dispersed phase was used after mixing the biocompatible polymer and donepezil base (manufacturer: Neuland Laboratories, India) with dichloromethane (manufacturer: J.T Baker, USA) and sufficiently dissolving it until it became transparent to the naked eye. A 0.1% polyvinyl alcohol (viscosity: 4.8~5.8 mPa·s) aqueous solution was used as the continuous phase. The continuous phase was connected to an emulsification device equipped with a porous membrane with a diameter of 40 μm, and the prepared dispersed phase was injected to prepare microspheres. The microsphere suspension was placed in a preparation container and stirred at a speed of 200 rpm.

The temperature of the membrane emulsifier and the preparation vessel was maintained at 25°C, and after the injection of the dispersed phase was completed, the suspension in the preparation vessel was stirred at a speed of 200 rpm and maintained at a temperature of 25°C for 60 minutes. Afterwards, the organic solvent was removed while maintaining the temperature at 45°C for 3 hours. After removal of the organic solvent, the temperature of the microparticle suspension was lowered to 25°C. The microsphere suspension was washed several times with ultrapure water to remove residual polyvinyl alcohol, and the microspheres were freeze-dried.

The type and amount of polymer used in this comparative example, the amount of drug used, the amount of pamoic acid used, the solvent used, the amount of dispersed phase solvent used, and the amount of continuous acid used are shown in Table 1 below. In Table 1 below, the molar ratio of drug:pamoic acid is shown based on the free base form of the drug.

Examples 1-10. Preparation of donepezil microspheres with added pamoic acid

The dispersed phase was used after mixing biocompatible polymer and donepezil base (manufacturer: Neuland Laboratories, India) and pamoic acid with dichloromethane (manufacturer: J.T Baker, USA) and sufficiently dissolving them until they became transparent to the naked eye. A 0.1% polyvinyl alcohol aqueous solution (viscosity: 4.8~5.8 mPa·s) was used as the continuous phase, and the continuous phase was connected to an emulsification device equipped with a porous membrane with a diameter of 40 μm, and the prepared dispersed phase was injected to prepare microspheres. The microsphere suspension was placed in a preparation container and stirred at a speed of 200 rpm.

The temperature of the membrane emulsifier and the preparation vessel was maintained at 25°C, and after the injection of the dispersed phase was completed, the suspension in the preparation vessel was stirred at a speed of 200 rpm and maintained at a temperature of 25°C for 60 minutes. Afterwards, the organic solvent was removed while maintaining the temperature at 45°C for 3 hours. After removal of the organic solvent, the temperature of the microparticle suspension was lowered to 25°C. The microsphere suspension was washed several times with ultrapure water to remove residual polyvinyl alcohol, and the microspheres were freeze-dried.

The type and amount of polymer used in this example, the amount of drug used, the amount of pamoic acid used, the solvent used, the amount of dispersed phase solvent used, and the amount of continuous acid used are shown in Table 1 below. In Table 1 below, the molar ratio of drug:pamoic acid is shown based on the free base form of the drug.

division polymer type API type Drug usage
(g) Pamoic acid usage (g) Drug:Pamoic acid molar ratio Polymer usage
(g) Disperse phase solvent usage (g) Continuous phase usage
(L) Pamoic acid content relative to the weight of microspheres (%, w/w) Example 1 PDL04A donepezil base 2.5 0.256 1:0.1 2.244 12.7 3.0 5.12 Example 2 PDL04A donepezil base 2.25 0.288 1:0.125 2.462 14.0 3.0 5.76 Example 3 PDL04A donepezil base 2.5 0.384 1:0.15 2.116 12.0 3.0 7.68 Example 4 PDL04A donepezil base 3 0.461 1:0.15 1.539 8.7 3.0 9.22 Example 5 PDL04A donepezil base 0.9 0.23 1:0.25 0.87 4.9 2.0 11.5 Example 6 R205S donepezil base 3 0.461 1:0.15 1.539 11.3 3.0 9.22 Example 7 PDL06 donepezil base 1.8 0.276 1:0.15 0.924 10.6 3.0 9.20 Example 8 PDL06 donepezil base 2.1 0.344 1:0.15 0.556 6.9 5.0 11.47 Example 9 PDL04A donepezil base 2.5 0.448 1:0.175 2.052 15.0 5.0 8.96 Example 10 PDL06 donepezil base 3.25 0.532 1:0.16 1.218 8.9 5.0 10.64 Comparative Example 1 PDL02A donepezil base 2 0 0 3 9.0 3.0 0 Comparative example 2 PDL02A donepezil base 2 0.05 1:0.02 2.95 8.8 3.0 1.00 Comparative Example 3 PDL02A donepezil base 2.25 0.05 1:0.02 2.7 8.1 3.0 1.00 Comparative Example 4 PDL06 donepezil base 2.4 0.049 1:0.02 0.551 3.1 5.0 1.63 Comparative Example 5 PDL45 donepezil base 0.8 0.041 1:0.05 0.159 7.8 3.0 4.10

(Viscosity of each polymer used: PDL04A (0.35-0.45 dL/g), PDL06 (0.54-0.66 dL/g), R205S (0.55-0.75 dL/g), PDL02A (0.16-0.24 dL/g), PDL45 ( 3.5-5.5dL/g))

Experimental Example 1. Measurement of drug content of sustained-release microspheres

To measure the drug content of the microspheres prepared in the above example, 10 mg of microspheres were completely dissolved in dimethyl sulfoxide and then diluted with a mobile phase. 20 uL of the diluted solution was injected into the HPLC and measured at a detection wavelength of 271 nm. The column used in this measurement was Inertsil ODS-3, 5 um, 4.6x150 mm, and the mobile phase was a mixture of phosphate buffer (pH 5.0) and acetonitrile in a ratio of 60:40 (v/v). The measured encapsulation amounts are shown in Table 2.

Experimental Example 2. Particle size analysis of sustained-release microspheres

A test was conducted using laser diffraction to quantitatively measure the average particle size, distribution, and uniformity of microspheres. The microspheres prepared in the examples were mixed with ultrapure water containing a surfactant, mixed with a vortex mixer for 20 seconds, and then placed in an ultrasonic generator and dispersed. The solution was placed in a particle size analyzer (Paar, PSA 900L, Austria) and the particle size was measured.

The particle size measurement results of the donepezil-containing sustained-release microspheres prepared in the comparative example are shown in Table 2 below.

division Drug content
(% w/w) Drug inclusion rate
(%) Microsphere size
(D50,um) Example 1 46.52 87.7 46.53 Example 2 40.68 90.4 49.28 Example 3 45.65 91.3 49.13 Example 4 61.02 101.7 51.53 Example 5 45.7 101.6 50.01 Example 6 57.58 91.7 48.59 Example 7 53.88 89.80 45.70 Example 8 64.89 92.70 50.09 Example 9 44.70 99.33 50.68 Example 10 58.37 97.28 50.72 Comparative Example 1 35.96 89.9 63.8 Comparative Example 2 36.28 90.70 62.17 Comparative Example 3 34.29 76.20 61.67 Comparative Example 4 80.00 91.18 53.89 Comparative Example 5 80.00 90.70 43.47

Experimental Example 3: Crystal analysis of dophenezyl, pamoic acid, and mixtures thereof through X-ray diffractometer

In order to confirm whether the crystal form of the substances themselves of donepezil and pamoic acid and the crystal form of the mixture of donepezil and pamoic acid contained in the microspheres are the same, the crystal form of the mixture of donepezil and pamoic acid in the microspheres prepared in the above example were examined. The crystal forms of donepezil and pamoic acid materials themselves were confirmed by XRD patterns using an X-ray diffractometer. The results are shown in Table 3 and Figure 2, respectively.

Table 3 shows the 2-Theta (±0.2) value of the peak shown as a result of X-ray diffraction analysis of donepezil and pamoic acid materials themselves.

donepezil pamoic acid donepezil pamoan mixture 2-Theta(±0.2) - - 5.747 - 9.448 - 9.786 - - - 11.115 - - - 11.523 - - 12.284 - 15.61 - 20.8068 - - - - 21.913 - - 24.240 26.294 26.244 - - 29.884 -

As can be seen in Table 3 and Figure 2, donepezil, pamoic acid, and mixtures of donepezil and pamoic acid exhibit specific 2-Theta peaks in XRD, as shown in Table 3. However, as can be seen in Figure 2, it was confirmed that this peak did not appear in microspheres containing donepezil and pamoic acid.

According to these results, it can be seen that donepezil and pamoic acid in the microspheres of the present invention exist in an amorphous form.

Experimental Example 4: Measurement of initial drug release in vitro from microspheres according to the content ratio of donepezil and pamoic acid

The following experiment was performed to confirm drug release from microspheres according to the content ratio of donepezil or a pharmaceutically acceptable salt thereof and pamoic acid used in the microspheres prepared in the above example.

Place 10 mg of microspheres in an HDPE wide-mouth bottle, fill with 50 mL of release test solution (pH 7.4 aqueous solution containing phosphate and sodium azide), and store in an incubator at 37°C. Take and secure 1 mL of this solution as the test solution, and add 1 mL of new release test solution to the wide-mouth bottle.

Samples were collected at a designated time, and content and release rate were analyzed using HPLC under the same analysis conditions as in Experiment 1. The results are shown in Table 4.

division Day 1 release of drug (%) Cumulative release amount of drug on day 7 (%) Example 2 0.6 21.2 Example 3 1.2 22.1 Example 4 2.04 24.8 Example 5 0.38 3.57 Example 6 5.09 29.9 Example 7 0.3 2.3 Example 8 0.3 2.1 Example 9 1.1 11.7 Example 10 1.5 26.6 Comparative Example 1 5.2 55.2 Comparative Example 2 5.0 51.5 Comparative Example 3 4.5 - Comparative Example 4 90.1 - Comparative Example 5 80.7 -

As can be seen in Table 4 above, in the case of the microspheres according to the present invention, the microspheres having a molar ratio of donepezil and pamoic acid used greater than 1:0.05 and less than or equal to 1:0.25 allow long-term release without excessive initial release of the drug upon administration of the microspheres. It was confirmed that the drug was released slowly over a period of time, which was desirable in terms of drug release. In addition, in the case of the microspheres according to the present invention, the molar ratio of donepezil and pamoic acid used is greater than 1:0.05 and less than 1:0.25, because the cumulative amount of drug released decreases as the ratio of pamoic acid increases, the drug content in the microspheres is reduced. Even if it is higher, excessive initial release of the drug can be prevented.

In addition, among the microspheres of the present invention, in the case of the microspheres of Examples 2, 4, and 5 in which the donepezil encapsulation rate is 89% or more and the molar ratio of donepezil and pamoic acid used is 1:0.05 or less, the cumulative release on day 7 is 50% or more. It was confirmed that excessive emission was observed.

In addition, when the content of donepezil used in the microspheres of the present invention was 80% by weight, it was found that a high release rate of more than 80% was observed from the first day of release, indicating a rapid initial release.

Experimental Example 5: Confirmation of pharmacokinetics of single-time subcutaneous administration of microspheres according to the present invention using animals

In order to confirm drug release from microspheres according to the content ratio of donepezil or its pharmaceutically acceptable salt and pamoic acid used in the microspheres prepared in the above example, a single dose of donepezil was administered to animals and then the pharmacokinetics were confirmed. For this purpose, donepezil concentration in blood was measured.

The administered dose of donepezil was measured to be 26.04 mg/head, dispersed in 0.3 mL suspension, and then intramuscularly or subcutaneously injected into SD rats. 0.25 to 0.5 mL of blood was collected at pre-planned times, and donepezil concentration in the blood was measured using HPLC. The AUC (%) on day 1 is shown in Table 5.

division Day 1 AUC of drug (%) Example 2 2.3 Example 3 2.3 Example 4 3.2 Example 7 0.6 Example 9 0.8 Example 10 0.9 Comparative Example 1 4.6 Comparative Example 2 4.1 Comparative Example 3 17.0

Claims (21)

As an active ingredient, donepezil or a pharmaceutically acceptable salt thereof; Sustained-release microspheres manufactured using pamoic acid and biocompatible polymers,
The molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of donepezil,
The microspheres are donepezil and are sustained-release microspheres having the characteristic of having a cumulative release amount of less than 30% over 7 days. As an active ingredient, donepezil or a pharmaceutically acceptable salt thereof; Sustained-release microspheres containing pamoic acid and biocompatible polymers,
The molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of donepezil,
The microspheres are donepezil and are sustained-release microspheres having the characteristic of having a cumulative release amount of less than 30% over 7 days. The sustained-release microspheres according to claim 1 or 2, wherein said donepezil or a pharmaceutically acceptable salt thereof and said pamoate are amorphous. The sustained-release microspheres according to claim 1 or 2, wherein the content of donepezil based on the free base form is less than 75% by weight based on the total weight of the microspheres. The sustained-release microsphere according to claim 1 or 2, wherein the donepezil is donepezil free base. The sustained-release microspheres according to claim 1 or 2, wherein the daily release amount of the active ingredient is less than 10%. The sustained-release microspheres according to claim 1 or 2, wherein the AUC of the microspheres upon daily release in vivo is less than 4% of the total AUC. The sustained-release microspheres according to claim 1 or 2, wherein the drug in the sustained-release microspheres is released for 1 to 6 months. The sustained-release microspheres according to claim 1 or 2, wherein the average particle diameter (Dv50) is 10 um or more. The method of claim 1 or 2, wherein the biocompatible polymer is poly(lactide-co-glycolide), poly(lactide-co-glycolide)glucose, polylactide, polyglycolide, polycaprolactone, and mixtures thereof; and sustained-release microspheres, which are at least one selected from the group consisting of polyglycolide, polylactide, and polyglycolide and polylactide copolymers. The sustained-release microspheres according to claim 1 or 2, which are for injection preparation. A pharmaceutical composition for preventing, improving or treating Alzheimer's disease or cognitive dysfunction, comprising the sustained-release microspheres according to claim 1 or 2. The pharmaceutical composition according to claim 12, further comprising a pharmaceutically acceptable carrier. The pharmaceutical composition according to claim 12, which is an injectable formulation. (a) donepezil or a pharmaceutically acceptable salt thereof as an active ingredient; Preparing a dispersed phase by dissolving pamoic acid and a biocompatible polymer in a solvent for the dispersed phase;
(b) preparing an emulsion by adding the dispersed phase prepared in step (a) to an aqueous solution containing a surfactant as a continuous phase;
(c) preparing a suspension containing microspheres by extracting the solvent for the dispersed phase in the dispersed phase of the emulsion prepared in step (b) into a continuous phase and evaporating the extracted solvent to form microspheres; and
(d) recovering the microspheres from the suspension of step (c) to prepare microspheres,
Method for producing sustained-release microspheres according to claim 1 or 2, wherein the molar ratio of the active ingredient: pamoic acid is greater than 1:0.05 and less than or equal to 1:0.25 based on the free base form of the active ingredient: The manufacturing method according to claim 15, wherein the content of the active ingredient is 40 to 70% by weight based on the total weight of the microspheres. The method of claim 15, wherein in step (a), the donepezil is in a free base form. The method of claim 15, wherein pamoic acid is added to a solution of the drug dissolved in the solvent for the dispersion phase in step (a). The method of claim 15, wherein the solvent for the dispersion phase is dichloromethane, ethyl acetate, ethyl formate, methyl acetate, methyl formate, butyl acetate, n-propyl acetate, isopropyl acetate, n-propyl formate, glycofurol, methyl A production method comprising isopropyl ketone, dimethyl carbonate, or a mixed solvent thereof. The method of claim 15, wherein the solvent for the dispersion phase consists of chloroform, acetone, acetonitrile, dimethyl sulfoxide, dimethyl formamide, methyl ethyl ketone, acetic acid, methyl alcohol, ethyl alcohol, propyl alcohol, benzyl alcohol, and mixed solvents thereof. A manufacturing method further comprising at least one selected from the group. The method of claim 15, wherein the biocompatible polymer is poly(lactide-co-glycolide), poly(lactide-co-glycolide)glucose, polylactide, polyglycolide, polycaprolactone, and mixtures thereof. ; and at least one selected from the group consisting of polyglycolide, polylactide, and polyglycolide and polylactide copolymer.