A capsule containing an extract of leonurus japonicus and a method for preparing the same

Abstract

The application belongs to the technical field of traditional Chinese medicines, and particularly relates to a capsule containing motherwort extract and a preparation method thereof. The capsule comprises a capsule shell and contents in the capsule shell; the contents are composed of motherwort extract and starch, and the weight ratio of motherwort used for preparing the motherwort extract to the starch is (2150-2895):(39-108); the capsule shell is composed of the following raw materials in parts by weight: modified cellulose 30-40 parts, sea hao vegetable polysaccharide 10-20 parts, gelling agent 3-6 parts, plasticizer 5-10 parts, and water 60-70 parts. In the preparation of the capsule shell, the modified cellulose and the sea hao vegetable polysaccharide are used in combination, the addition of the modified cellulose can improve the disintegration performance and stability of the capsule shell, and the addition of the sea hao vegetable polysaccharide can improve the mechanical performance of the capsule shell, so that the prepared capsule containing the motherwort extract has excellent storage stability, mechanical performance and disintegration performance.

Description

Technical Field

[0001] The invention belongs to the technical field of traditional Chinese medicines, and particularly relates to a capsule containing motherwort extract and a preparation method thereof. Background Art

[0002] Motherwort capsules are a type of pharmaceutical preparation made by encapsulating motherwort extract with edible materials. They are primarily used for regulating menstruation, postpartum uterine bleeding, and incomplete uterine involution. Traditional capsules are primarily made of gelatin, a material that has significant limitations. On the one hand, gelatin comes from animals, and there is a risk of animal-borne diseases being transmitted during production. Furthermore, its quality is easily affected by factors such as animal breed and breeding environment, leading to unstable product quality. On the other hand, gelatin capsules have high requirements for environmental temperature and humidity during storage and use. They are prone to softening and adhesion under high temperature and high humidity conditions, and become brittle and crack under low temperature and dry conditions. This significantly limits the application range and storage period of gelatin capsules.

[0003] In order to overcome these shortcomings of gelatin capsules, products using plant-based materials to prepare capsule shells have begun to appear on the market. Cellulose, as an abundant natural polymer compound, has good biocompatibility and degradability, making it one of the candidate materials that has attracted much attention. However, capsule shells prepared from ordinary cellulose have problems such as poor disintegration performance and slow drug release, which makes it difficult to meet actual medication needs. Although some simple chemical modification methods can improve the performance of cellulose to a certain extent, the effect is still not ideal, especially in improving the thermal stability and drug release efficiency of the capsule shell, which still needs further breakthroughs. In addition, the mechanical properties of the capsule shell are also a key factor affecting its quality. During the capsule filling process, the capsule shell needs to withstand a certain amount of mechanical pressure. If the mechanical properties are insufficient, it is easy to break, resulting in drug leakage, affecting the quality and production efficiency of the drug.

[0004] Although some research has been conducted on plant-derived capsule shells, satisfactory results have not yet been achieved in terms of simultaneously improving the disintegration performance, thermal stability, and mechanical properties of the capsule shells. Therefore, developing a capsule shell material with excellent comprehensive properties is of great practical significance for promoting the development of capsule dosage forms. Summary of the Invention

[0005] In order to overcome the shortcomings of the existing technology, the primary purpose of the present invention is to provide a capsule containing motherwort extract. In the preparation of the capsule shell, the present invention uses modified cellulose and sea hail polysaccharide in combination. The addition of modified cellulose can improve the disintegration performance and stability of the capsule shell, while the addition of sea hail polysaccharide improves the mechanical properties of the capsule shell. The obtained capsule containing motherwort extract has excellent storage stability.

[0006] Another object of the present invention is to provide a method for preparing the capsule containing the motherwort extract.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] A capsule containing motherwort extract comprises a capsule shell and contents in the capsule shell; the contents are composed of the motherwort extract and starch, and the weight ratio of the motherwort to the starch used to prepare the motherwort extract is (2150-2895):(39-108); the capsule shell is composed of the following raw materials in parts by weight: 30-40 parts of modified cellulose, 10-20 parts of kelp polysaccharide, 3-6 parts of a gelling agent, 5-10 parts of a plasticizer, and 60-70 parts of water.

[0009] Furthermore, the modified cellulose is prepared by the following preparation process:

[0010] (1) Dispersing cellulose particles in water, then adding sodium periodate for pretreatment, then adding sodium chlorite solution and acetic acid solution for pre-oxidation, and finally adding 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide and sodium hypochlorite for oxidation reaction to obtain carboxylated cellulose;

[0011] (2) The carboxylated cellulose obtained in step (1) is added to water, and then 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and N-ethyl-L-glutamine are added to react to obtain the modified cellulose.

[0012] Furthermore, in step (1), the dosage ratio of the cellulose particles, water, sodium periodate, sodium chlorite solution, acetic acid solution, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide and sodium hypochlorite is 1 g: (200-250) mL: (1-1.5) g: (150-200) mL: (8-12) mL: (0.01-0.02) g: (0.1-0.15) g: (0.3-0.5) g; the concentration of the sodium chlorite solution is 0.15-0.2 mol / L; and the concentration of the acetic acid solution is 0.8-1 mol / L.

[0013] Furthermore, in step (1), the pretreatment temperature is 50-60°C and the time is 1-2 h; the pre-oxidation temperature is 40-50°C and the time is 1-3 h; and the oxidation temperature is 60-65°C and the time is 3-5 h.

[0014] Furthermore, the amount ratio of the carboxylated cellulose, water, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and N-ethyl-L-glutamine in step (2) is 1 g: (100-120) mL: (3-5) g: (3-5) g: (6-8) g.

[0015] Furthermore, the reaction time in step (2) is 8-10 h.

[0016] Furthermore, the plasticizer is one of glycerol, propylene glycol, and sorbitol; and the gelling agent includes one or more of gum arabic, carrageenan, and pectin.

[0017] The preparation method of the capsule containing the motherwort extract comprises the following steps:

[0018] (a) heating water to 60-70° C. according to the weight of each raw material in the capsule shell, then adding modified cellulose, schizonepeta polysaccharide, and a gelling agent, stirring until a paste forms, then adding a plasticizer and continuing to stir to obtain a mixture; casting the mixture into a film, drying it, and processing it into a capsule shell having a cavity structure;

[0019] (b) According to the weight of each raw material in the content, chop the motherwort, add water and boil it three times, adding 8-12 times the amount of water each time, and boil it for 1-3 hours each time. The decoctions are combined, filtered, and the filtrate is concentrated to a relative density of 1.14-1.18, cooled, and 1-3 times the amount of ethanol is added, stirred, and allowed to stand for 10-14 hours. Filtered, the filter residue is washed with 40%-50% ethanol solution, the washing liquid and the filtrate are combined, and the ethanol is recovered under reduced pressure. The residual liquid is concentrated to a thick paste, starch is added, mixed, dried, crushed, and sieved to obtain a dry paste powder; the dry paste powder is loaded into the capsules of step (a).

[0020] Furthermore, in step (b), the temperature for concentrating the filtrate to a relative density of 1.14-1.18 is 40-60°C; the drying temperature is 60-80°C, and the drying time is 12-18 hours.

[0021] The present invention has the following effects compared to the prior art:

[0022] 1. The present invention provides a capsule containing a motherwort extract, comprising a capsule shell and contents within the capsule shell. The present invention utilizes a combination of modified cellulose and kelp polysaccharide to prepare the capsule shell. The addition of modified cellulose improves the disintegration and stability of the capsule shell. Specifically, the present invention constructs carboxylated cellulose through sodium periodate pretreatment, sodium chlorite preoxidation, and TEMPO-NaBr-NaClO synergistic oxidation. Finally, the modified cellulose is amidated and grafted with N-ethyl-L-glutamine to form a modified cellulose with a "carboxyl-amide" bifunctional structure. This reduces cellulose crystallinity and enhances its hydrophilicity, synergistically promoting drug release. When the capsule enters the digestive fluid environment of the body, the hydrophilic groups rapidly bind to water molecules, causing the capsule shell to rapidly absorb water and swell, thereby accelerating the disintegration of the capsule shell, allowing for faster release of the drug within and improving dissolution. In addition, the grafting of N-ethyl-L-glutamine forms a protective barrier on the cellulose molecular chain. Under high temperature conditions, this stable molecular structure can reduce the damage to the cellulose molecular structure caused by external environmental factors, maintain the integrity of the capsule shell, and ensure that the capsule can still maintain good performance under high temperature and high humidity storage conditions.

[0023] 2. The present invention also incorporates a polysaccharide from the seaweed plant in the capsule shell. The abundant hydroxyl groups and other functional groups on its molecular chains form hydrogen bonds, van der Waals forces, and other intermolecular interactions with the carboxyl groups and amide bonds on the modified cellulose molecular chains, as well as with other components such as the gelling agent. This tightly connects the individual molecular chains together, forming a denser and more stable three-dimensional network structure, thereby enhancing the strength and toughness of the capsule shell. Furthermore, the excellent antioxidant activity of the polysaccharide from the seaweed plant further improves the storage stability of the drug, helping to preserve the active ingredients in the motherwort extract and increase its utilization rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 FT-IR spectra of cellulose particles, carboxylated cellulose and modified cellulose in Preparation Example 1. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be further described below in conjunction with specific embodiments. However, it should be understood by those skilled in the art that the following examples are only intended to illustrate the present invention and should not be construed as limiting the present invention. Specific conditions not specified in the examples are to be followed according to conventional conditions or the conditions recommended by the manufacturer. All reagents or instruments used, unless otherwise specified, are conventional products obtained from commercial channels.

[0026] The preparation method of the polysaccharide of the following examples and comparative examples is as follows: adding the powder of the crushed polysaccharide of the ...

[0027] Preparation Example 1

[0028] A modified cellulose prepared by the following preparation process:

[0029] (1) The bamboo pulp was crushed, dried and ground to obtain cellulose particles; the raw materials or solutions were weighed according to the dosage ratio of cellulose, water, sodium periodate, sodium chlorite solution, acetic acid solution, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical (TEMPO), sodium bromide and sodium hypochlorite: 1 g: 220 mL: 1.2 g: 180 mL: 10 mL: 0.015 g: 0.12 g: 0.4 g; the cellulose was dispersed in water, and then sodium periodate was added and pretreated at 55 °C for 1.5 h; after pretreatment, 0.15 M sodium chlorite solution and 0.8 M acetic acid solution were added to the mixed system, and preoxidized at 45 °C with stirring for 2 h; after the preoxidation, TEMPO, sodium bromide and sodium hypochlorite were added to the system, and the pH was adjusted to 10 with sodium hydroxide solution, and then oxidized at 60 °C with stirring for 4 h; after the oxidation, 500 The reaction was terminated with mL of anhydrous ethanol, and the collected solid was filtered and washed with deionized water, and dried at 60 °C for 13 h to obtain carboxylated cellulose.

[0030] (2) Carboxylated cellulose, deionized water, 1-ethyl-(3-dimethylaminopropyl)carbodiimide (EDC), N-hydroxysuccinimide (NHS) and N-ethyl-L-glutamine were weighed in a ratio of 1 g:110 mL:4 g:4 g:7 g. The carboxylated cellulose obtained in step (1) was added to deionized water, stirred evenly, and then EDC, NHS and N-ethyl-L-glutamine were added. The mixture was reacted at room temperature for 9 h. The mixture was centrifuged and the collected solid product was washed with water to obtain modified cellulose.

[0031] The FT-IR images of the above cellulose particles, carboxylated cellulose and modified cellulose are shown in Figure 2. Figure 1 As shown, Figure 1Curves 1, 2, and 3 correspond to cellulose particles, carboxylated cellulose, and modified cellulose, respectively. Compared with curve 1, the peak at 1740 cm in curve 2 is -1 The typical carbonyl (C=O) vibration peak appeared at 3400 cm -1 3450 cm in the left and right directions -1 The 1550 cm-1 peak in curve 3 indicates that the cellulose is successfully carboxylated. -1 and 1610 cm -1 The peaks at the bottom are the vibration characteristic peaks of amide II band and amide I band, respectively, indicating the successful grafting of N-ethyl-L-glutamine.

[0032] Preparation Example 2

[0033] A modified cellulose prepared by the following preparation process:

[0034] (1) The bamboo pulp was crushed, dried and ground to obtain cellulose particles; the raw materials or solutions were weighed according to the dosage ratio of cellulose, water, sodium periodate, sodium chlorite solution, acetic acid solution, TEMPO, sodium bromide and sodium hypochlorite: 1 g: 200 mL: 1 g: 150 mL: 8 mL: 0.01 g: 0.1 g: 0.3 g; the cellulose was dispersed in water, and then sodium periodate was added and pretreated at 50 ° C for 2 h; after pretreatment, 0.2 M sodium chlorite solution and 1 M acetic acid solution were added to the mixed system, and preoxidized at 40 ° C for 3 h under stirring; after the preoxidation, TEMPO, sodium bromide and sodium hypochlorite were added to the system, and the pH was adjusted to 10 with sodium hydroxide solution, and then oxidized at 60 ° C for 5 h under stirring; after the oxidation, 500 mL of anhydrous ethanol was added to the reaction system to terminate the reaction, and the collected solid was filtered and washed with deionized water, and dried at 60 ° C for 15 h to obtain carboxylated cellulose.

[0035] (2) Weigh each raw material or water according to the ratio of carboxylated cellulose, deionized water, EDC, NHS and N-ethyl-L-glutamine: 1 g:100 mL: 3 g:3 g:6 g, add the carboxylated cellulose obtained in step (1) into deionized water, stir evenly, then add EDC, NHS and N-ethyl-L-glutamine, and react at room temperature for 8 h; centrifuge, and wash the collected solid product with water to obtain modified cellulose.

[0036] Preparation Example 3

[0037] A modified cellulose prepared by the following preparation process:

[0038] (1) The bamboo pulp was crushed, dried and ground to obtain cellulose particles; the raw materials or solutions were weighed according to the dosage ratio of cellulose, water, sodium periodate, sodium chlorite solution, acetic acid solution, TEMPO, sodium bromide and sodium hypochlorite: 1 g: 250 mL: 1.5 g: 200 mL: 12 mL: 0.02 g: 0.15 g: 0.5 g; the cellulose was dispersed in water, and then sodium periodate was added and pretreated at 60 ° C for 1 h; after pretreatment, 0.15 M sodium chlorite solution and 1 M acetic acid solution were added to the mixed system, and preoxidized at 50 ° C for 1 h under stirring; after the preoxidation, TEMPO and sodium hypochlorite were added to the system, and the pH was adjusted to 10 with sodium hydroxide solution, and then oxidized at 65 ° C for 3 h under stirring; after the oxidation, 500 mL of anhydrous ethanol was added to the reaction system to terminate the reaction, and the collected solid was filtered and washed with deionized water, and dried at 60 ° C for 12 h to obtain carboxylated cellulose.

[0039] (2) Weigh each raw material or water according to the ratio of carboxylated cellulose, deionized water, EDC, NHS and N-ethyl-L-glutamine: 1 g:120 mL: 5 g:5 g:8 g, add the carboxylated cellulose obtained in step (1) into deionized water, stir evenly, then add EDC, NHS and N-ethyl-L-glutamine, and react at room temperature for 10 h; centrifuge, and wash the collected solid product with water to obtain modified cellulose.

[0040] Example 1

[0041] Example 1 provides a capsule containing motherwort extract, comprising a capsule shell and contents in the capsule shell; wherein the contents consist of motherwort extract and starch, and the weight ratio of motherwort to starch used to prepare the motherwort extract is 2500:80; the capsule shell is composed of the following raw materials in parts by weight: 35 parts of modified cellulose of Preparation Example 1, 15 parts of sea hail polysaccharide, 5 parts of carrageenan, 8 parts of sorbitol, and 65 parts of water.

[0042] Example 1 also provides a method for preparing the capsule containing the motherwort extract, comprising the following steps:

[0043] (1) Preparation of capsule shell: Heat water to 65°C according to the weight proportions of the raw materials for the capsule shell, then add the modified cellulose, silybum polysaccharide, and carrageenan prepared in Preparation Example 1, stir until a paste forms, then add sorbitol and continue stirring to obtain a mixture; cast the mixture into a film, dry it, and process it into a capsule shell having a cavity structure;

[0044] (2) Take 25,000 g of motherwort, chop it, add water and boil it three times, add 12 times, 10 times and 8 times the amount of water for the first, second and third times respectively, boil it for 1 hour each time, combine the decoctions, filter, concentrate the filtrate at 40°C to a concentrate with a relative density of 1.16, let it cool, add ethanol in an amount equal to that of the concentrate, stir well, let it stand for 12 hours, filter, wash the filter residue with 45% ethanol, combine the washing liquid with the filtrate, recover the ethanol under reduced pressure, concentrate the remaining liquid to a thick paste, add 800 g of starch, mix well, dry at 70°C for 16 hours, crush and sieve to obtain a dry paste powder, put the dry paste powder into the capsules of step (1) to make 10,000 capsules, and obtain capsules containing motherwort extract (0.36 g per capsule).

[0045] Example 2

[0046] Example 2 provides a capsule containing motherwort extract, including a capsule shell and contents in the capsule shell; wherein the contents are composed of motherwort extract and starch, and the weight ratio of motherwort to starch used to prepare the motherwort extract is 2400:45; the capsule shell is composed of the following raw materials in parts by weight: 30 parts of modified cellulose in Preparation Example 1, 10 parts of sea hail polysaccharide, 3 parts of gum arabic, 5 parts of propylene glycol, and 60 parts of water.

[0047] Example 2 also provides a method for preparing the capsule containing the motherwort extract, comprising the following steps:

[0048] (1) Preparation of capsule shell: Heat water to 60°C according to the weight proportions of the raw materials for the capsule shell, then add the modified cellulose, silybum polysaccharide, and gum arabic prepared in Preparation Example 1, stir until a paste forms, then add propylene glycol and continue stirring to obtain a mixture; cast the mixture into a film, dry it, and process it into a capsule shell having a cavity structure;

[0049] (2) Take 24,000 g of motherwort, chop it, add water and boil it three times, add 12 times, 10 times and 8 times the amount of water for the first, second and third times respectively, boil it for 1 hour each time, combine the decoctions, filter, concentrate the filtrate at 45°C to a concentrate with a relative density of 1.14, let it cool, add ethanol in an amount equal to that of the concentrate, stir well, let it stand for 12 hours, filter, wash the filter residue with 45% ethanol, combine the washing liquid with the filtrate, recover the ethanol under reduced pressure, concentrate the remaining liquid to a thick paste, add 450 g of starch, mix well, dry at 80°C for 12 hours, crush and sieve to obtain a dry paste powder, put the dry paste powder into the capsules of step (1) to make 9,600 capsules, and obtain capsules containing motherwort extract (0.36 g per capsule).

[0050] Example 3

[0051] Example 3 provides a capsule containing motherwort extract, including a capsule shell and contents in the capsule shell; wherein the contents are composed of motherwort extract and starch, and the weight ratio of motherwort to starch used to prepare the motherwort extract is 2895:108; the capsule shell is composed of the following raw materials in parts by weight: 40 parts of modified cellulose in Preparation Example 1, 20 parts of sea hail polysaccharide, 6 parts of pectin, 10 parts of glycerin, and 70 parts of water.

[0052] Example 3 also provides a method for preparing the capsule containing the motherwort extract, comprising the following steps:

[0053] (1) Preparation of capsule shell: Heat water to 70°C according to the weight proportions of the raw materials for the capsule shell, then add the modified cellulose, silybum polysaccharide, and pectin prepared in Preparation Example 1, stir until a paste forms, then add glycerin and continue stirring to obtain a mixture; cast the mixture into a film, dry it, and process it into a capsule shell having a cavity structure;

[0054] (2) Take 28950 g of motherwort, chop it, add water and boil it three times, add 12 times, 10 times and 8 times the amount of water for the first, second and third time respectively, boil it for 1 hour each time, combine the decoctions, filter, concentrate the filtrate at 60 ° C to a concentrate with a relative density of 1.18, let it cool, add ethanol in an amount equal to the concentrate, stir well, let it stand for 12 hours, filter, wash the filter residue with 45% ethanol, combine the washing liquid with the filtrate, recover the ethanol under reduced pressure, concentrate the remaining liquid to a thick paste, add 1080 g of starch, mix well, dry at 60 ° C for 18 hours, crush and sieve to obtain a dry paste powder, put the dry paste powder into the capsules of step (1) to make 11580 capsules, and obtain capsules containing motherwort extract (0.36 g per capsule).

[0055] Comparative Example 1

[0056] Comparative Example 1 is substantially the same as Example 1, except that the modified cellulose in Example 1 is replaced by the cellulose particles of Preparation Example 1.

[0057] Comparative Example 2

[0058] Comparative Example 2 is substantially the same as Example 1, except that the Psoralea corylifolia polysaccharide in Example 1 is replaced by pullulan.

[0059] Comparative Example 3

[0060] Comparative Example 3 is substantially the same as Example 1, except that the Herba Lysimachiae polysaccharide in Example 1 is omitted.

[0061] Test example

[0062] (1) Accelerated stability test: The products prepared in Examples 1-3 and Comparative Examples 1-3 were stored at a temperature of 40±2°C and a relative humidity of 75±5%. After 0, 1, 3, and 6 months, the content of stachydrine hydrochloride in the products was determined according to the HPLC-ELSD method in Part I of the Chinese Pharmacopoeia (2020 edition), and the retention rate of stachydrine hydrochloride was determined. The retention rate (%) = the content of stachydrine hydrochloride in the capsule after storage / the initial content of stachydrine hydrochloride in the capsule × 100%. The results are shown in Table 1.

[0063] (2) Dissolution and disintegration time test: According to the corresponding method of the "Chinese Pharmacopoeia" (2020 edition), the dissolution and disintegration time of the products prepared in Examples 1-3 and Comparative Examples 1-3 were measured using stachydrine hydrochloride as the detection index. The results are shown in Table 2.

[0064] (3) Mechanical properties test: According to the method of GB / T 1040.3-2006, the capsule shells prepared in Examples 1-3 and Comparative Examples 1-2 were subjected to tensile tests under the same conditions. The tests were performed 5 times, with 10 samples in each group tested. The elongation at break and the breaking strength were calculated by taking the average values.

[0065] Table 1

[0066]

[0067] Table 2

[0068]

[0069] Table 3

[0070]

[0071] As shown in Tables 1 and 2, the capsules containing Leonurus herb extract prepared in Examples 1-3 of the present invention can still maintain the stability of the Leonurus herb extract after being placed in a high temperature and high humidity environment for 6 months. In addition, the capsule shell has a short disintegration time and high solubility, which enables the drug to be quickly released from the capsule, thereby improving the bioavailability of the drug. Comparative Example 1 replaces the modified cellulose in Example 1 with ordinary cellulose particles. The disintegration time is significantly prolonged, the solubility decreases, and the retention rate of stachydrine hydrochloride is also low after being placed for 6 months, indicating that the addition of the modified cellulose of the present invention can improve the disintegration performance of the capsule shell and impart good stability to the capsule. The present invention carboxylates cellulose and grafts N-ethyl-L-glutamine, which can make the drug more easily released and has good thermal stability. The capsule can still maintain good performance in a high temperature environment.

[0072] As shown in Table 3, compared to Example 1, when the polysaccharides from the hyacinthia serrata were replaced with pullulan or omitted in Comparative Examples 2 and 3, the elongation at break and breaking strength of the capsule shells decreased. This indicates that the addition of polysaccharides from the hyacinthia serrata further improved the mechanical properties of the capsule shells, resulting in greater flexibility and strength during the filling process, making the capsule shells less susceptible to breakage. Furthermore, the excellent antioxidant activity of polysaccharides from the hyacinthia serrata further enhances the storage stability of the drug, helping to preserve the active ingredients in the motherwort extract and increasing its utilization.

[0073] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the same. The basic principles and main features of the present invention have been described above using specific implementation schemes. Modifications or substitutions may be made based on the present invention, but such modifications or substitutions do not detract from the essence of the corresponding technical solutions from the scope of protection claimed by the present invention.

Claims

1. A capsule containing motherwort extract, characterized in that: The invention comprises a capsule shell and contents inside the capsule shell; the contents are composed of motherwort extract and starch, and the weight ratio of motherwort to starch used in preparing the motherwort extract is (2150-2895): (39-108); the capsule shell is composed of the following raw materials in parts by weight: 30-40 parts of modified cellulose, 10-20 parts of kelp polysaccharide, 3-6 parts of gelling agent, 5-10 parts of plasticizer, and 60-70 parts of water; The modified cellulose is prepared by the following preparation process: (1) Dispersing cellulose particles in water, then adding sodium periodate for pretreatment, then adding sodium chlorite solution and acetic acid solution for pre-oxidation, and finally adding 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide and sodium hypochlorite for oxidation reaction to obtain carboxylated cellulose; (2) The carboxylated cellulose obtained in step (1) is added to water, and then 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and N-ethyl-L-glutamine are added to react to obtain the modified cellulose.

2. The capsule containing the motherwort extract according to claim 1, wherein The amount ratio of the cellulose particles, water, sodium periodate, sodium chlorite solution, acetic acid solution, 2,2,6,6-tetramethylpiperidin-1-oxyl free radical, sodium bromide and sodium hypochlorite in step (1) is 1 g: (200-250) mL: (1-1.5) g: (150-200) mL: (8-12) mL: (0.01-0.02) g: (0.1-0.15) g: (0.3-0.5) g; the concentration of the sodium chlorite solution is 0.15-0.2 mol / L; the concentration of the acetic acid solution is 0.8-1 mol / L.

3. The capsule containing the motherwort extract according to claim 1, wherein In step (1), the pretreatment temperature is 50-60°C and the time is 1-2 h; the pre-oxidation temperature is 40-50°C and the time is 1-3 h; the oxidation temperature is 60-65°C and the time is 3-5 h.

4. The capsule containing the motherwort extract according to claim 1, wherein The amount ratio of carboxylated cellulose, water, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide and N-ethyl-L-glutamine in step (2) is 1 g: (100-120) mL: (3-5) g: (3-5) g: (6-8) g.

5. The capsule containing the motherwort extract according to claim 1, wherein The reaction time in step (2) is 8-10 h.

6. The capsule containing the motherwort extract according to claim 1, wherein The plasticizer is one of glycerol, propylene glycol, and sorbitol; the gelling agent includes one or more of gum arabic, carrageenan, and pectin.

7. The method for preparing the capsule containing the motherwort extract according to any one of claims 1 to 6, characterized in that: The following steps are involved: (a) heating water to 60-70° C. according to the weight of each raw material in the capsule shell, then adding modified cellulose, schizonepeta polysaccharide, and a gelling agent, stirring until a paste forms, then adding a plasticizer and continuing to stir to obtain a mixture; casting the mixture into a film, drying it, and processing it into a capsule shell having a cavity structure; (b) According to the weight of each raw material in the content, chop the motherwort, add water and boil it three times, adding 8-12 times the amount of water each time, and boil it for 1-3 hours each time. The decoctions are combined, filtered, and the filtrate is concentrated to a relative density of 1.14-1.18, cooled, and 1-3 times the amount of ethanol is added, stirred, and allowed to stand for 10-14 hours. Filtered, the filter residue is washed with 40%-50% ethanol solution, the washing liquid and the filtrate are combined, and the ethanol is recovered under reduced pressure. The residual liquid is concentrated to a thick paste, starch is added, mixed, dried, crushed, and sieved to obtain a dry paste powder; the dry paste powder is loaded into the capsules of step (a).

8. The method for preparing capsules containing Leonurus japonicus extract according to claim 7, wherein: In step (b), the temperature for concentrating the filtrate to a relative density of 1.14-1.18 is 40-60° C.; the drying temperature is 60-80° C. and the drying time is 12-18 h.

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