Lenaclotide capsule preparation and preparation method thereof

Abstract

The invention provides a linaclotide capsule preparation and a preparation method thereof. The linaclotide capsule preparation comprises a plurality of linaclotide particles and a capsule shell, the capsule shell is filled with the linaclotide particles, and each linaclotide particle sequentially comprises a medicine carrying bead, a linaclotide coating layer and a protective coating layer from inside to outside. The linaclotide coating layer at least comprises linaclotide, calcium chloride dihydrate, leucine and steric hindrance primary amine. The linaclotide capsule preparation disclosed by the invention is relatively good in drug effect stability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pharmaceutical preparations, in particular to a linaclotide capsule preparation and a preparation method thereof. BACKGROUND

[0002] Linaclotide is a drug for treating constipation-predominant irritable bowel syndrome and chronic idiopathic constipation, which activates the receptor Guanylate Cyclase-C (GC-C) in the intestinal epithelial cells to increase the production of cyclic guanosine monophosphate. The increase in intracellular guanosine concentration can stimulate intestinal fluid secretion and accelerate gastrointestinal transit, thereby increasing defecation frequency.

[0003] Linaclotide amino acid sequence:

[0004] L-cysteinyl-L-cysteinyl-L-glutaminyl-L-tyrosinyl-L-cysteinyl-L-cysteinyl-L-asparaginyl-L-prolyl-L-alanyl-L-cysteinyl-L-threonyl-L-glycyl-L-cysteinyl-L-tyrosine, cyclic (1-6), (2-10), (5-13) - three disulfide bonds;

[0005] Chemical structure formula:

[0006]

[0007] In preparation, transportation and storage, high temperature and high humidity environment can easily cause linaclotide drug substances in linaclotide preparations to be unstable, affect the efficacy, and even cause side reactions to intensify. For example, the application number CN202311464033.7 makes the surface of the microcrystalline cellulose micro-pellet core coated with linaclotide and the coating liquid of auxiliary material 1 and the coating liquid of auxiliary material 2. The coating formed by the coating liquid of auxiliary material 2 can isolate external moisture, oxygen and the like to a certain extent, can improve the adverse effects of light, high humidity and high temperature on the preparation, and greatly improves the stability of the preparation during transportation, storage and use. However, since the coating needs to be dried at an elevated temperature, even if the temperature is not higher than 50℃, the molecular structure of the linaclotide drug substance will still be damaged under drying, thereby affecting the efficacy. SUMMARY

[0008] The purpose of the present application is to overcome the deficiencies in the prior art, and to provide a linaclotide capsule preparation and a preparation method thereof, which can further improve the efficacy stability of the linaclotide capsule preparation.

[0009] The purpose of the present application is achieved by the following technical solutions:

[0010] A linaclotide capsule preparation, comprising a plurality of linaclotide particles and a capsule shell, the plurality of linaclotide particles being filled in the capsule shell, each of the linaclotide particles sequentially comprising a drug-loaded bead, a linaclotide coating layer and a protective coating layer from inside to outside;

[0011] The linaclotide coating layer comprises at least linaclotide, calcium chloride dihydrate, leucine and a sterically hindered primary amine.

[0012] In one of the embodiments, the drug-loaded bead is a microcrystalline cellulose bead.

[0013] In one of the embodiments, the capsule shell comprises alum and titanium dioxide.

[0014] In one of the embodiments, the sterically hindered primary amine is at least one of 2,2,6,6-tetramethylpiperidinamine, 1-adamantylmethylamine and 2-amino-adamantane acid.

[0015] In one of the embodiments, the molar ratio of the linaclotide to the sterically hindered primary amine (calculated on the basis of amino groups) is 1:(3-7).

[0016] In one of the embodiments, the molar ratio of the calcium chloride dihydrate (calculated on the basis of Ca 2+ ), the leucine and the linaclotide is (40-100):(20-50):1.

[0017] In one of the embodiments, the mass of the linaclotide in the linaclotide capsule preparation is 72 μg, 145 μg or 290 μg.

[0018] In one of the embodiments, the linaclotide coating layer further comprises a binder and / or an antioxidant.

[0019] In one of the embodiments, the binder is at least one of methylcellulose, sodium carboxymethylcellulose, ethylcellulose, polyvinyl alcohol, hypromellose, povidone, gelatin, gum arabic.

[0020] In one of the embodiments, the antioxidant is L-methionine or propyl gallate.

[0021] In one of the embodiments, the amount of the binder in the linaclotide coating layer is 0.3% w / w-0.4% w / w.

[0022] In one of the embodiments, the amount of the antioxidant in the linaclotide coating layer is 0.01% w / w-0.2% w / w.

[0023] In one of the embodiments, the protective coating layer comprises an ethylcellulose aqueous dispersion, a methacrylate copolymer and an acrylic resin complex dispersion.

[0024] In one embodiment, the weight percentage of ethyl cellulose in the ethyl cellulose aqueous dispersion is 15% w / w.

[0025] In one embodiment, the mass percentage of acrylic resin in the acrylic resin composite dispersion is 20% w / w.

[0026] A preparation method of a linaclotide capsule preparation, for preparing the linaclotide capsule preparation of any one of the above embodiments, the preparation method of the linaclotide capsule preparation comprises the following steps:

[0027] Obtaining the drug-loaded beads and components of the linaclotide coating layer;

[0028] Mixing the components of the linaclotide coating layer to obtain a linaclotide coating solution;

[0029] Performing drug-loading coating operation on the drug-loaded beads with the linaclotide coating solution to form a linaclotide coating layer on the surface of the drug-loaded beads;

[0030] Performing protective coating operation on the linaclotide coating layer to form a protective coating layer on the surface of the linaclotide coating layer.

[0031] In one embodiment, the drug-loading coating operation on the drug-loaded beads with the linaclotide coating solution is performed at a coating spray temperature of 24-55°C.

[0032] In one embodiment, the protective coating operation on the linaclotide coating layer is performed at a coating spray temperature of 24-55°C.

[0033] Compared with the prior art, the present application has at least the following advantages:

[0034] The linaclotide capsule preparation of the present application adds calcium chloride dihydrate, leucine and a space-hindered primary amine in the linaclotide coating layer, wherein the Ca2 + binds to the Glu3 / Asp side chain carboxyl group of linaclotide, enhances the mechanical elastic modulus of the linaclotide coating layer, and the crystal water of calcium chloride dihydrate is released at 40-50°C, relieving the peptide chain dehydration stress of linaclotide during the process of temperature at 40-50°C; the hydrophobic side chain of leucine reduces the surface energy of the linaclotide coating layer, inhibiting particle aggregation; the primary amine of the space-hindered primary amine rapidly binds to the N-terminal alpha-amino group and Glu 3 carboxyl group of linaclotide, eliminating the N-terminal and Glu 3The intramolecular charge repulsion between molecules forms an electrostatic shielding layer, improving coating cracks caused by electrostatic repulsion and reducing charge-driven water molecule penetration, thus inhibiting hydrolysis. Furthermore, the steric hindrance of the primary amine precisely filling the disulfide ring of linaclotide inhibits SS isomerization of linaclotide at high temperatures. Additionally, the steric hindrance of the hydrophobic end of the primary amine embedding into the Met group of linaclotide... 5 -Tyr 4 The pocket design reduces the contact between the sulfur atoms of linaclotide and oxygen molecules, thereby effectively improving the efficacy and stability of linaclotide capsule formulations. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 This is a flowchart illustrating a method for preparing a linaclotide capsule formulation according to an embodiment of the present invention. Detailed Implementation

[0037] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0038] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] This application provides a linaclotide capsule formulation. The aforementioned linaclotide capsule formulation comprises a plurality of linaclotide particles and a capsule shell. The plurality of linaclotide particles fill the capsule shell, and each linaclotide particle, from the inside out, consists of a drug-loaded bead, a linaclotide coating layer, and a protective coating layer. The linaclotide coating layer comprises at least linaclotide, calcium chloride dihydrate, leucine, and a steric hindrance primary amine.

[0041] The aforementioned linaclotide capsule formulation incorporates calcium chloride dihydrate, leucine, and a sterically hindering primary amine in its coating layer. The calcium chloride dihydrate contains Ca... 2+ With linaclotide Glu 3 The / Asp side chain carboxyl group binding enhances the mechanoelastic modulus of the linaclotide coating, and the water of crystallization of calcium chloride dihydrate is released during the 40℃~50℃ range, alleviating the dehydration stress of the linaclotide peptide chain during this temperature range. The hydrophobic side chain of leucine reduces the surface energy of the linaclotide coating, inhibiting particle aggregation. The steric hindrance of the primary amine allows for rapid binding of the primary amine to the N-terminal α-amino group and Glu3 carboxyl group of linaclotide, eliminating the binding between the N-terminus and Glu3. 3 The intramolecular charge repulsion between molecules forms an electrostatic shielding layer, improving coating cracks caused by electrostatic repulsion and reducing charge-driven water molecule penetration, thus inhibiting hydrolysis. Furthermore, the steric hindrance of the primary amine precisely filling the disulfide ring of linaclotide inhibits SS isomerization of linaclotide at high temperatures. Additionally, the steric hindrance of the hydrophobic end of the primary amine embedding into the Met group of linaclotide... 5 -Tyr 4 The pocket design reduces the contact between the sulfur atoms of linaclotide and oxygen molecules, thereby effectively improving the efficacy and stability of linaclotide capsule formulations.

[0042] To better understand the linaclotide capsule formulation of this application, the following further explanation is provided:

[0043] One embodiment of the linaclotide capsule formulation includes a plurality of linaclotide particles and a capsule shell, wherein the plurality of linaclotide particles fill the capsule shell, and each linaclotide particle comprises, from the inside out, a drug-loaded bead, a linaclotide coating layer, and a protective coating layer. Further, the linaclotide coating layer comprises at least linaclotide, calcium chloride dihydrate, leucine, and a steric hindrance primary amine.

[0044] The aforementioned linaclotide capsule formulation incorporates calcium chloride dihydrate, leucine, and a sterically hindering primary amine in its coating layer. The calcium chloride dihydrate contains Ca... 2+ With linaclotide Glu 3The / Asp side chain carboxyl group binds to enhance the mechanoelastic modulus of the linaclotide coating, and the water of crystallization of calcium chloride dihydrate is released during the 40℃~50℃ range, alleviating the dehydration stress of the linaclotide peptide chain during the temperature range of 40℃~50℃; the hydrophobic side chain of leucine reduces the surface energy of the linaclotide coating, inhibiting particle aggregation; the steric hindrance of the primary amine rapidly binds to the N-terminal α-amino group and Glu of linaclotide. 3 Carboxyl group binding, eliminating the N-terminus from Glu 3 The intramolecular charge repulsion between molecules forms an electrostatic shielding layer, improving coating cracks caused by electrostatic repulsion and reducing charge-driven water molecule penetration, thus inhibiting hydrolysis. Furthermore, the steric hindrance of the primary amine precisely filling the disulfide ring of linaclotide inhibits SS isomerization of linaclotide at high temperatures. Additionally, the steric hindrance of the hydrophobic end of the primary amine embedding into the Met group of linaclotide... 5 -Tyr 4 The pocket design reduces the contact between the sulfur atoms of linaclotide and oxygen molecules, thereby effectively improving the efficacy and stability of linaclotide capsule formulations.

[0045] In one embodiment, the linaclotide coating layer further includes trehalose. Further, the mass ratio of trehalose to steric hindrance amine in the linaclotide coating layer is 1:(20-27). It is understood that while the use of steric hindrance amine in linaclotide effectively improves its pharmacological stability under high temperature and humidity conditions, excessive use of steric hindrance amine can lead to over-binding to the carbonyl group of the main peptide chain of linaclotide, resulting in a decrease in the α-helix content of linaclotide, which in turn affects its pharmacological stability. In other words, the effect of using steric hindrance amine on improving the pharmacological stability of linaclotide is limited. To further improve the pharmacological stability of linaclotide under high temperature and humidity conditions, in this embodiment… The application further incorporates trehalose into the linaclotide coating layer. The C2 / C3 / C4 hydroxyl groups of trehalose combine with the carbonyl groups of the main peptide chain to form an alternative hydrogen bond network, maintaining the β-turn structure at high temperatures and improving the high-temperature retention rate of the α-helix content. Furthermore, trehalose preferentially binds to water molecules in the linaclotide coating layer, reducing water activity and thus inhibiting the hydrolysis reaction of linaclotide. Additionally, the glassy formation of trehalose increases the viscosity of the system, inhibiting thermal motion and suppressing the cleavage of disulfide bonds in linaclotide at high temperatures.

[0046] It is understandable that when trehalose is used in linaclotide, trehalose and the N-terminal α-amino group of linaclotide are prone to glycosylation, which can lead to a decrease in the efficacy of linaclotide. In this application, the primary amine is sterically hindered from binding to the N-terminal α-amino group of linaclotide first, thereby reducing the effect of trehalose on the efficacy of linaclotide. In addition, since trehalose is highly hygroscopic, its addition to linaclotide can easily cause excessive dissolution of linaclotide. Therefore, a protective coating is formed on the outer layer of the linaclotide coating layer, thereby ensuring the efficacy stability of linaclotide.

[0047] In one embodiment, the drug-loaded beads are microcrystalline cellulose beads. Further, the particle size of the drug-loaded beads is 500 μm to 1000 μm.

[0048] In one embodiment, the capsule shell comprises alum and titanium dioxide, with silica filling the gaps between gelatin molecules, effectively reducing moisture permeation channels and thus significantly lowering water vapor permeability.

[0049] In one embodiment, the steric hindrance primary amine is at least one selected from 2,2,6,6-tetramethylpiperidinamine, 1-adamantanemethylamine, and 2-aminoadamantanoic acid, which effectively ensures improved pharmacodynamic stability of linaclotide.

[0050] In one embodiment, the molar ratio of linaclotide to sterically hindering primary amine (based on amino group) is 1:(3-7), which effectively ensures improved pharmacodynamic stability of linaclotide.

[0051] In one embodiment, calcium chloride dihydrate (in Ca...) 2+ The molar ratio of leucine to linaclotide (40-100):(20-50):1 effectively ensures the improved efficacy stability of linaclotide.

[0052] In one embodiment, the mass of linaclotide in the linaclotide capsule formulation is 72 μg, 145 μg, or 290 μg.

[0053] In one embodiment, the linaclotide coating layer further includes an adhesive and / or an antioxidant.

[0054] In one embodiment, the adhesive is at least one selected from methylcellulose, sodium carboxymethylcellulose, ethylcellulose, polyacrylamide, hydroxypropyl methylcellulose, povidone, gelatin, and gum arabic.

[0055] In one embodiment, the antioxidant is L-methionine or propyl gallate.

[0056] In one embodiment, the amount of binder in the linaclotide coating layer is 0.3% w / w to 0.4% w / w.

[0057] In one embodiment, the amount of antioxidant in the linaclotide coating layer is 0.01% w / w to 0.2% w / w.

[0058] In one embodiment, the protective coating layer comprises an ethyl cellulose aqueous dispersion, a methacrylate copolymer, and an acrylic resin composite dispersion. Further, the ethyl cellulose in the ethyl cellulose aqueous dispersion comprises 15% w / w by weight. Further, the acrylic resin composite dispersion comprises 20% w / w by weight of acrylic resin. Further, the protective coating layer comprises the following components in parts by weight: 30 to 60 parts of ethyl cellulose aqueous dispersion; 20 to 40 parts of methacrylate copolymer; and 10 to 30 parts of acrylic resin composite dispersion.

[0059] This application also provides a method for preparing a linaclotide capsule formulation, used to prepare the linaclotide capsule formulation of any of the above embodiments. The method for preparing the linaclotide capsule formulation includes the following steps: obtaining the components of drug-loaded beads and linaclotide coating layer; mixing the components of linaclotide coating layer to obtain linaclotide coating solution; using linaclotide coating solution to perform a drug-loaded bead coating operation to form a linaclotide coating layer on the surface of the drug-loaded beads; and performing a protective coating operation on the linaclotide coating layer to form a protective coating layer on the surface of the linaclotide coating layer.

[0060] The above-mentioned method for preparing linaclotide capsules effectively forms a linaclotide coating layer and a protective coating layer on the drug-loaded beads.

[0061] To better understand the preparation method of the linaclotide capsule formulation of this application, the following further explanation is provided:

[0062] The preparation method of the linaclotide capsule formulation according to one embodiment includes the following steps:

[0063] S100, Obtain the components of the drug-loaded beads and the linaclotide coating layer;

[0064] S200. The components of the linaclotide coating layer are mixed to obtain the linaclotide coating solution.

[0065] S300. The drug-loaded beads are coated with linaclotide coating solution to form a linaclotide coating layer on the surface of the drug-loaded beads.

[0066] S400. Perform a protective coating operation on the linaclotide coating layer to form a protective coating layer on the surface of the linaclotide coating layer.

[0067] The above-mentioned method for preparing linaclotide capsules effectively forms a linaclotide coating layer and a protective coating layer on the drug-loaded beads.

[0068] In one embodiment, linaclotide coating solution was used to coat the drug-loaded beads. The coating spray temperature was 24°C to 55°C, which effectively improved the efficacy stability of linaclotide when the coating spray temperature was greater than 50°C, and also helped to improve the preparation efficiency of linaclotide capsule formulation.

[0069] In one embodiment, a protective coating operation is performed on the linaclotide coating layer, and the coating spray temperature is 24°C to 55°C. This effectively achieves the pharmacodynamic stability of linaclotide when the coating spray temperature is greater than 50°C, and also helps to improve the preparation efficiency of linaclotide capsule formulation.

[0070] In one embodiment, the components of the linaclotide coating layer are mixed, and the specific operation is as follows:

[0071] Purified water and hydrochloric acid were mixed to produce a solution with a pH of 1.5–2.0. Calcium chloride dihydrate was added to the solution and mixed until a clear solution was formed. Then, a sterically hindering primary amine was added to the solution and mixed until a clear solution was formed. Next, leucine was added to the solution and mixed until a clear solution was formed. The pH of the solution was measured, and hydrochloric acid was added if necessary to produce a solution with a pH of 1.5–2.0. Then, a binder was added to the solution and mixed until a clear solution was formed. Finally, linaclotide was added to the solution and mixed for 30–100 minutes.

[0072] In one embodiment, the components of the linaclotide coating layer are mixed, and the specific operation is as follows:

[0073] Purified water and hydrochloric acid are mixed to produce a solution with a pH of 1.5–2.0. Calcium chloride dihydrate is added to the solution and mixed until a clear solution is formed. Then, a sterically hindering primary amine is added to the solution and mixed until a clear solution is formed. Next, leucine is added to the solution and mixed until a clear solution is formed. The pH of the solution is measured, and hydrochloric acid is added if necessary to produce a solution with a pH of 1.5–2.0. Then, linaclotide is added to the latter solution and mixed for 30–100 min to obtain solution A, which is set aside for later use. Purified water and hydrochloric acid are mixed to produce a solution with a pH of 1.5–2.0. Trehalose is added to the solution and mixed until a clear solution is formed. Then, a binder is added to the solution and mixed until a clear solution is formed. Finally, solution A is added to the solution and stirred for 20–50 min. It is understandable that allowing the sterically hindered primary amine to mix evenly with linaclotide before mixing with trehalose and the binder effectively improves the mixing uniformity of trehalose in linaclotide. Furthermore, allowing the sterically hindered primary amine to bind first to the N-terminal α-amino group of linaclotide effectively reduces the glycosylation reaction between linaclotide and trehalose, and facilitates the full binding of the sterically hindered primary amine to the N-terminal α-amino group and Glu of linaclotide. 3 The carboxyl group binding facilitates the steric hindrance of the primary amine's complete filling of the disulfide ring of linaclotide, and facilitates the complete embedding of the hydrophobic end of the primary amine into the linaclotide Met group. 5 -Tyr 4 In the pocket, the C2 / C3 / C4 hydroxyl groups of trehalose combine with the carbonyl group of the main peptide chain to form an alternative hydrogen bond network, and the glassy state of trehalose protects the sterically hindered binding structure of primary amines and linaclotide, effectively improving the pharmacological stability of linaclotide.

[0074] In one embodiment, the drug-loaded beads are coated with a linaclotide coating solution. The specific procedure is as follows: microcrystalline cellulose beads are added to a microfluidic column coating machine to fluidize the beads, with an air volumetric flow rate of 25 m³ / s. 3 / h~35m 3 The microcrystalline cellulose beads were heated to 35℃~40℃. Then, the coating solution was added to a micro-column fluidized bed coating machine with an inlet temperature of 40℃~50℃, a spray rate of 2mL / min~5mL / min, an atomization pressure of 0.8bar~1.5bar, and a spray temperature of 24℃~55℃. The beads were then dried at 35℃~50℃ for 20min~40min to obtain activated beads.

[0075] In one embodiment, a protective coating operation is performed on the linaclotide coating layer, specifically as follows: An aqueous dispersion of ethyl cellulose, a copolymer of methacrylate, and a composite dispersion of acrylic resin are sheared and mixed at a stirring speed of 300 rpm to 450 rpm for 1 to 3 hours to ensure the uniformity of the protective coating solution. Then, the mixture is allowed to stand for 20 to 30 minutes to degas, yielding the protective coating solution for later use. Next, active beads are added to a microfluidic bed coating machine to fluidize the microcrystalline cellulose beads, with an air volumetric flow rate of 25 m³ / min. 3 / h~35m 3 The active beads are heated to 35℃~40℃, and then the protective coating solution is added to the micro-column fluidized bed coating machine. The inlet temperature is 40℃~50℃, the spray rate is 3mL / min~6mL / min, the atomization pressure is 1.0bar~1.8bar, and the air volume is [missing information]. The spray temperature is 24℃~55℃. Then the beads are dried at 35℃~50℃ for 30min~45min.

[0076] Compared with the prior art, the present invention has at least the following advantages:

[0077] The linaclotide capsule formulation of the present invention comprises calcium chloride dihydrate, leucine, and a sterically hindered primary amine added to the linaclotide coating layer, wherein the calcium chloride dihydrate contains Ca... 2+ With linaclotide Glu 3 The / Asp side chain carboxyl group binds to enhance the mechanoelastic modulus of the linaclotide coating, and the water of crystallization of calcium chloride dihydrate is released during the 40℃~50℃ range, alleviating the dehydration stress of the linaclotide peptide chain during the temperature range of 40℃~50℃; the hydrophobic side chain of leucine reduces the surface energy of the linaclotide coating, inhibiting particle aggregation; the steric hindrance of the primary amine rapidly binds to the N-terminal α-amino group and Glu of linaclotide. 3 Carboxyl group binding, eliminating the N-terminus from Glu 3 The intramolecular charge repulsion between molecules forms an electrostatic shielding layer, improving coating cracks caused by electrostatic repulsion and reducing charge-driven water molecule penetration, thus inhibiting hydrolysis. Furthermore, the steric hindrance of the primary amine precisely filling the disulfide ring of linaclotide inhibits SS isomerization of linaclotide at high temperatures. Additionally, the steric hindrance of the hydrophobic end of the primary amine embedding into the Met group of linaclotide... 5 -Tyr 4 The pocket design reduces the contact between the sulfur atoms of linaclotide and oxygen molecules, thereby effectively improving the efficacy and stability of linaclotide capsule formulations.

[0078] Example 1

[0079] Preparation of linaclotide coating solution: Purified water and hydrochloric acid were mixed to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2. Then, calcium chloride dihydrate was added to the solution and mixed until a clear solution was obtained. Next, 2,2,6,6-tetramethylpiperidinamine was added to the solution and mixed until a clear solution was obtained. Then, leucine was added to the solution and mixed until a clear solution was obtained. Then, L-methionine was added to the solution and mixed until a clear solution was obtained. The pH of the solution was tested, and hydrochloric acid was added to the solution to adjust the pH to 1.8 ± 0.2 if necessary. Then, hydroxypropyl methylcellulose was added to the solution and mixed until a clear solution was obtained. Finally, linaclotide was added to the solution and stirred for 90 minutes to obtain the linaclotide coating solution.

[0080] Preparation of active beads: Dry microcrystalline cellulose beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads. The air volume flow rate was 30 m³ / min. 3 / h, heat the microcrystalline cellulose beads to a temperature of 38℃, then add the linaclotide coating solution to the micro-column fluidized bed coating machine, with an inlet temperature of 48℃, a spray rate of 3mL / min, an atomization pressure of 1.2bar, and a spray temperature of 52℃. Then dry the beads at a temperature of 50℃ for 28min to obtain activated beads.

[0081] Preparation of protectively coated active beads: Ethyl cellulose aqueous dispersion, methacrylate copolymer, and acrylic resin composite dispersion were sheared and mixed at a stirring speed of 400 rpm for 2 h, followed by standing for 25 min to degas, yielding a protective coating solution for later use; the active beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads, with an air volume flow rate of 30 m³ / h. 3 / h, and heat the active beads to a temperature of 38℃. Then, add the protective coating solution to the micro-column fluidized bed coating machine with an inlet temperature of 48℃, a spray rate of 5mL / min, an atomization pressure of 1.5bar, and an air volume of , and a spray temperature of 52℃. Then, dry the beads at a temperature of 50℃ for 40min.

[0082] Example 2

[0083] Preparation of linaclotide coating solution: Purified water and hydrochloric acid were mixed to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2. Then, calcium chloride dihydrate was added to the solution and mixed until a clear solution was obtained. Next, 2,2,6,6-tetramethylpiperidinamine was added to the solution and mixed until a clear solution was obtained. Then, leucine was added to the solution and mixed until a clear solution was obtained. L-methionine was then added to the solution and mixed until a clear solution was obtained. The pH of the solution was tested, and hydrochloric acid was added to the solution as needed to adjust the pH to 1.8 ± 0.2. Linaclotide was then added to the solution and mixed for 90 minutes to obtain solution A, which was set aside. Alternatively, purified water and hydrochloric acid were mixed to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2. Then, trehalose was added to the solution and mixed until a clear solution was obtained. Hydroxypropyl methylcellulose was then added to the solution and mixed until a clear solution was obtained. Solution A was added to the solution and stirred for 45 minutes to obtain the linaclotide coating solution.

[0084] Preparation of active beads: Dry microcrystalline cellulose beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads. The air volume flow rate was 30 m³ / min. 3 / h, heat the microcrystalline cellulose beads to a temperature of 38℃, then add the linaclotide coating solution to the micro-column fluidized bed coating machine, with an inlet temperature of 48℃, a spray rate of 3mL / min, an atomization pressure of 1.2bar, and a spray temperature of 52℃. Then dry the beads at a temperature of 50℃ for 28min to obtain activated beads.

[0085] Preparation of protectively coated active beads: Ethyl cellulose aqueous dispersion, methacrylate copolymer, and acrylic resin composite dispersion were sheared and mixed at a stirring speed of 400 rpm for 2 h, followed by standing for 25 min to degas, yielding a protective coating solution for later use; the active beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads, with an air volume flow rate of 30 m³ / h. 3 / h, and heat the active beads to a temperature of 38℃. Then, add the protective coating solution to the micro-column fluidized bed coating machine with an inlet temperature of 48℃, a spray rate of 5mL / min, an atomization pressure of 1.5bar, and an air volume of , and a spray temperature of 52℃. Then, dry the beads at a temperature of 50℃ for 40min.

[0086] Comparative Example 1

[0087] Preparation of linaclotide coating solution: Purified water and hydrochloric acid were mixed to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2; then, calcium chloride dihydrate was added to the solution and mixed until a clear solution was obtained; then, leucine was added to the solution and mixed until a clear solution was obtained; then, L-methionine was added to the solution and mixed until a clear solution was obtained; the pH of the solution was tested, and hydrochloric acid was added to the solution to adjust the pH to 1.8 ± 0.2 if necessary; then, hydroxypropyl methylcellulose was added to the solution and mixed until a clear solution was obtained; then, linaclotide was added to the solution and stirred for 90 minutes to obtain the linaclotide coating solution.

[0088] Preparation of active beads: Dry microcrystalline cellulose beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads. The air volume flow rate was 30 m³ / min. 3 / h, heat the microcrystalline cellulose beads to a temperature of 38℃, then add the linaclotide coating solution to the micro-column fluidized bed coating machine, with an inlet temperature of 48℃, a spray rate of 3mL / min, an atomization pressure of 1.2bar, and a spray temperature of 52℃. Then dry the beads at a temperature of 50℃ for 28min to obtain activated beads.

[0089] Preparation of protectively coated active beads: Ethyl cellulose aqueous dispersion, methacrylate copolymer, and acrylic resin composite dispersion were sheared and mixed at a stirring speed of 400 rpm for 2 h, followed by standing for 25 min to degas, yielding a protective coating solution for later use; the active beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads, with an air volume flow rate of 30 m³ / h. 3 / h, and heat the active beads to a temperature of 38℃. Then, add the protective coating solution to the micro-column fluidized bed coating machine with an inlet temperature of 48℃, a spray rate of 5mL / min, an atomization pressure of 1.5bar, and an air volume of , and a spray temperature of 52℃. Then, dry the beads at a temperature of 50℃ for 40min.

[0090] Comparative Example 2

[0091] Preparation of linaclotide coating solution: Purified water and hydrochloric acid were mixed to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2. Then, calcium chloride dihydrate was added to the solution and mixed until a clear solution was obtained. Next, leucine was added to the solution and mixed until a clear solution was obtained. Then, L-methionine was added to the solution and mixed until a clear solution was obtained. The pH of the solution was tested, and if necessary, hydrochloric acid was added to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2. Then, linaclotide was added to the solution and mixed for 90 minutes to obtain solution A, which was set aside. Purified water and hydrochloric acid were mixed to adjust the pH to obtain a solution with a pH of 1.8 ± 0.2. Trehalose was added to the solution and mixed until a clear solution was obtained. Then, hydroxypropyl methylcellulose was added to the solution and mixed until a clear solution was obtained. Solution A was added to the solution and stirred for 45 minutes to obtain the linaclotide coating solution.

[0092] Preparation of active beads: Dry microcrystalline cellulose beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads. The air volume flow rate was 30 m³ / min. 3 / h, heat the microcrystalline cellulose beads to a temperature of 38℃, then add the linaclotide coating solution to the micro-column fluidized bed coating machine, with an inlet temperature of 48℃, a spray rate of 3mL / min, an atomization pressure of 1.2bar, and a spray temperature of 52℃. Then dry the beads at a temperature of 50℃ for 28min to obtain activated beads.

[0093] Preparation of protectively coated active beads: Ethyl cellulose aqueous dispersion, methacrylate copolymer, and acrylic resin composite dispersion were sheared and mixed at a stirring speed of 400 rpm for 2 h, followed by standing for 25 min to degas, yielding a protective coating solution for later use; the active beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads, with an air volume flow rate of 30 m³ / h. 3 / h, and heat the active beads to a temperature of 38℃. Then, add the protective coating solution to the micro-column fluidized bed coating machine with an inlet temperature of 48℃, a spray rate of 5mL / min, an atomization pressure of 1.5bar, and an air volume of , and a spray temperature of 52℃. Then, dry the beads at a temperature of 50℃ for 40min.

[0094] Comparative Example 3

[0095] Preparation of linaclotide coating solution: Purified water and hydrochloric acid were mixed to adjust the pH to 1.8 ± 0.2. Then, calcium chloride dihydrate was added to the solution and mixed until a clear solution was obtained. Next, trehalose was added to the solution and mixed until a clear solution was obtained. Then, leucine was added to the solution and mixed until a clear solution was obtained. L-methionine was then added to the solution and mixed until a clear solution was obtained. The pH of the solution was tested, and hydrochloric acid was added as needed to adjust the pH to 1.8 ± 0.2. Linaclotide was then added to the solution and mixed for 90 minutes to obtain solution A, which was set aside. Alternatively, purified water and hydrochloric acid were mixed to adjust the pH to 1.8 ± 0.2. Then, 2,2,6,6-tetramethylpiperidinamine was added to the solution and mixed until a clear solution was obtained. Hydroxypropyl methylcellulose was then added to the solution and mixed until a clear solution was obtained. Solution A was added to the solution and stirred for 45 minutes to obtain the linaclotide coating solution.

[0096] Preparation of active beads: Dry microcrystalline cellulose beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads. The air volume flow rate was 30 m³ / min. 3 / h, heat the microcrystalline cellulose beads to a temperature of 38℃, then add the linaclotide coating solution to the micro-column fluidized bed coating machine, with an inlet temperature of 48℃, a spray rate of 3mL / min, an atomization pressure of 1.2bar, and a spray temperature of 52℃. Then dry the beads at a temperature of 50℃ for 28min to obtain activated beads.

[0097] Preparation of protectively coated active beads: Ethyl cellulose aqueous dispersion, methacrylate copolymer, and acrylic resin composite dispersion were sheared and mixed at a stirring speed of 400 rpm for 2 h, followed by standing for 25 min to degas, yielding a protective coating solution for later use; the active beads were added to a micro-column fluidized bed coating machine to fluidize the microcrystalline cellulose beads, with an air volume flow rate of 30 m³ / h. 3 / h, and heat the active beads to a temperature of 38℃. Then, add the protective coating solution to the micro-column fluidized bed coating machine with an inlet temperature of 48℃, a spray rate of 5mL / min, an atomization pressure of 1.5bar, and an air volume of , and a spray temperature of 52℃. Then, dry the beads at a temperature of 50℃ for 40min.

[0098] The drug-loaded particles obtained in Examples 1 and 2 and the drug-loaded particles obtained in Comparative Examples 1 to 3 were calculated based on a linaclotide content of 72 μg, and then filled into capsule shells to obtain linaclotide capsule formulations. The linaclotide capsule formulations obtained in Examples 1 and 2, and Comparative Examples 1 to 3, were subjected to influence factor tests. The test conditions were light exposure (5000±500 Lx, UV intensity 90 μW / cm2), high temperature (40℃ and 60℃), and high humidity (RH 92.5%) for 15 days. Samples were taken on the 15th day to detect related substances. The results are shown in Table 1.

[0099] Table 1: Total Impurity Content in Linaclotide Capsules

[0100]

[0101] As can be seen from Table 1, the linaclotide capsule formulations in Examples 1-2 have good stability, especially the linaclotide capsule formulation in Example 2. In particular, a comparison between the linaclotide capsule formulations in Example 1 and Comparative Example 1 shows that the addition of the steric hindrance primary amine effectively improves the stability of linaclotide. A comparison between the linaclotide capsule formulations in Example 2 and Comparative Example 2 shows that the addition of trehalose alone actually results in poor stability of linaclotide. A comparison between the linaclotide capsule formulations in Example 2 and Comparative Example 3 shows that adjusting the order of addition of the steric hindrance primary amine, trehalose, and linaclotide, i.e., mixing trehalose with linaclotide first and then adding the steric hindrance primary amine for mixing, actually results in a linaclotide capsule formulation with even worse stability.

[0102] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A linaclotide capsule formulation, comprising a plurality of linaclotide particles and a capsule shell, wherein the plurality of linaclotide particles are filled within the capsule shell, characterized in that, Each of the linaclotide particles consists of, from the inside out, a drug-loaded bead, a linaclotide coating layer, and a protective coating layer; The linaclotide coating layer comprises at least linaclotide, calcium chloride dihydrate, leucine, and a sterically hindering primary amine.

2. The linaclotide capsule formulation according to claim 1, characterized in that, The drug-loaded beads are microcrystalline cellulose beads; and / or, The capsule shell comprises alum and titanium dioxide; and / or, The steric hindrance primary amine is at least one selected from 2,2,6,6-tetramethylpiperidineamine, 1-adamantanemethylamine, and 2-aminoadamantanoic acid.

3. The linaclotide capsule formulation according to claim 1, characterized in that, The molar ratio of the linaclotide to the sterically hindering primary amine (based on the amino group) is 1:(3-7); and / or, The calcium chloride dihydrate (in Ca) 2+ The molar ratio of the leucine and the linaclotide is (40-100):(20-50):1; and / or, The mass of linaclotide in the linaclotide capsule formulation is 72 μg, 145 μg, or 290 μg.

4. The linaclotide capsule formulation according to claim 1, characterized in that, The linaclotide coating layer also includes an adhesive and / or an antioxidant.

5. The linaclotide capsule formulation according to claim 4, characterized in that, The adhesive is at least one selected from methylcellulose, sodium carboxymethylcellulose, ethylcellulose, polyacrylamide, hydroxypropyl methylcellulose, povidone, gelatin, and gum arabic; and / or, The antioxidant is L-methionine or propyl gallate.

6. The linaclotide capsule formulation according to claim 4, characterized in that, The amount of the binder in the linaclotide coating layer is 0.3% w / w to 0.4% w / w; and / or, The amount of antioxidant in the linaclotide coating layer is 0.01% w / w to 0.2% w / w.

7. The linaclotide capsule formulation according to claim 1, characterized in that, The protective coating layer comprises an ethyl cellulose aqueous dispersion, a methacrylate copolymer, and an acrylic resin composite dispersion.

8. The linaclotide capsule formulation according to claim 7, characterized in that, The ethyl cellulose aqueous dispersion contains 15% w / w ethyl cellulose; and / or, The acrylic resin composite dispersion contains 20% w / w of acrylic resin by mass.

9. A method for preparing a linaclotide capsule formulation, characterized in that, The method for preparing the linaclotide capsule formulation according to any one of claims 1 to 8 comprises the following steps: Obtain the components of the drug-loaded beads and the linaclotide coating layer; The components of the linaclotide coating layer are mixed to obtain a linaclotide coating solution. The drug-loaded beads are coated with the linaclotide coating solution to form a linaclotide coating layer on the surface of the drug-loaded beads. A protective coating operation is performed on the linaclotide coating layer to form a protective coating layer on the surface of the linaclotide coating layer.

10. The method for preparing linaclotide capsules according to claim 9, characterized in that, The drug-loaded beads are coated with the linaclotide coating solution at a spray temperature of 24°C to 55°C; and / or, The linaclotide coating layer is subjected to a protective coating operation, with the coating spray temperature ranging from 24°C to 55°C.

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