Method for preparing plant hollow capsules

Abstract

The present application belongs to the technical field of pharmaceutical excipients, and particularly relates to a preparation method of a plant hollow capsule. The present application comprises the following steps: (1) according to the mass fraction, 100 parts of cellulose is weighed, 300-600 parts of purified water above 75 DEG C is added, and the cellulose is stirred to be dissolved to form a cellulose glue solution; (2) the glue solution is transferred to a glue tank of a full-automatic capsule production line, and is dipped under room temperature; (3) after dipping, the mold is run to the upper platform of the full-automatic capsule production line, and compressed air is used to dry and shape the capsule; (4) after shaping, fine drying, demolding, cutting, and sleeving are completed on the full-automatic capsule production line, and the plant hollow capsule is obtained. The present application is scientific and reasonable in design, does not need to add a gelling agent, reduces the molding control temperature, is energy-saving and environment-friendly, the prepared hollow capsule has low water content, the application range of the hollow capsule is expanded, and the drug dissolution performance is more stable in application.

Description

Technical Field

[0001] The invention belongs to the technical field of pharmaceutical excipients, and particularly relates to a method for preparing a plant hollow capsule. Background Art

[0002] According to the "General Rules for Capsules (Hollow Capsules)" published by the Chinese Pharmacopoeia Commission, hollow capsules typically consist of two parts: a cap and a body. Both are cylindrical, with the longer end called the body and the shorter end called the cap. The cap and body should fit tightly together and lock together. The capsule should have a smooth surface, uniform color, a smooth cut, no deformation, and no odor.

[0003] Empty capsules can be categorized by the source of their primary film-forming material: animal-derived and non-animal-derived. Animal-derived empty capsules are those whose primary film-forming material originates from animals. Non-animal-derived empty capsules are hollow capsules whose film-forming material is non-animal and contains no animal-derived substances. Examples include empty capsules made of hypromellose, pullulan, and hydroxypropyl starch. The production process involves preparing the glue solution, dipping in the glue, shaping, drying, demolding, cutting, and fitting the capsules to form the empty capsules.

[0004] In existing hollow capsule production processes, the properties of the film-forming material are utilized to shape the capsule after dipping. For example, animal-derived hollow capsules are shaped by the gelling properties of animal gelatin, while non-animal-derived hollow capsules are shaped by adding a gelling agent. Hydroxypropyl methylcellulose hollow capsules can also be shaped by its thermal gelling properties. However, these shaping methods require high temperatures, long production cycles, and poor drug dissolution performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for preparing plant hollow capsules. The method has a scientific and reasonable design, does not require the addition of a gelling agent, reduces the molding control temperature, is energy-saving and environmentally friendly, and the prepared hollow capsules have a low water content, thereby expanding the application range of the hollow capsules and achieving more stable drug dissolution performance during application.

[0006] The method for preparing the plant hollow capsule of the present invention comprises the following steps:

[0007] (1) Weigh 100 parts by mass of cellulose, add 300-600 parts of purified water above 75°C, and stir at a low speed until the cellulose is completely dissolved to form a bubble-free cellulose glue;

[0008] (2) transferring the glue solution to the glue tank of the fully automatic capsule production line and dipping the glue at room temperature;

[0009] (3) After the mold is dipped in glue, it moves to the upper platform of the fully automatic capsule production line, and compressed air is used to quickly dry and shape the capsule;

[0010] (4) After shaping, fine drying, demoulding, cutting, and fitting are completed on a fully automatic capsule production line to obtain the plant hollow capsules.

[0011] The cellulose is a mixture of three viscosities: 3.0 MPa.s, 6.5 MPa.s, and 50 MPa.s.

[0012] Preferably, cellulose with a viscosity of 3.0 mPa.s accounts for 20-35% of the weight of the mixture, cellulose with a viscosity of 6.5 mPa.s accounts for 50-75% of the weight of the mixture, and cellulose with a viscosity of 50 mPa.s accounts for 5-15% of the weight of the mixture.

[0013] Preferably, the cellulose is one or more of hydroxypropyl methylcellulose, hydroxyethyl methylcellulose, methylcellulose or hydroxyethyl cellulose.

[0014] Preferably, in step (1), during low-speed stirring, the stirring speed is controlled at 15-25 r / min, and the temperature of the cellulose glue is 35-50° C. If a small amount of bubbles appear, vacuum defoaming can be used.

[0015] Preferably, in step (3), the pressure of the compressed air is 0.5 MPa. Depending on the capsule model and the viscosity ratio of the raw materials, the flow rate of the compressed air is controlled to be 10-15 m / s, and the drying time using the compressed air is 3-5 seconds.

[0016] Preferably, in step (3), during the drying and shaping process, the water loss of the glue on the mold is controlled at 50-60wt% according to the capsule model and the viscosity ratio of the raw materials.

[0017] Preferably, in step (4), the fine drying temperature is 30-50° C., and the water content of the hollow capsules produced is at least 2%.

[0018] Preferably, in step (1), a pharmaceutical grade or food grade pigment is also added in an amount of 0-5.0 wt%.

[0019] The present invention provides a new capsule shaping method after hollow capsules are dipped in glue. The provided shaping method is suitable for materials that have good film-forming properties but no gelling properties, such as cellulose. Compared with high-temperature thermal gel shaping using hypromellose, this shaping method can effectively reduce the molding control temperature and save energy. It is also suitable for cellulose without thermal gelling properties, thereby broadening the selection space of capsule materials.

[0020] The principle of drying and shaping in the present invention is that compressed air causes rapid local air flow, thereby accelerating the rapid loss of water from the glue on the mold. As the glue on the mold loses water rapidly, the content of cellulose with different viscosities increases rapidly, and its viscosity also increases rapidly, achieving the purpose of shaping the glue.

[0021] Compared with the prior art, the present invention achieves the following beneficial effects:

[0022] (1) The hollow capsules produced by the present invention fully comply with the provisions of the Chinese Pharmacopoeia, and the water content of the hollow capsules is as low as 2%, which is more suitable for filling with absorbent medicinal powders, expanding the application range of the hollow capsules and providing a better choice for pharmaceutical factories;

[0023] (2) The introduction of compressed air in the present invention reduces the drying time of the hollow capsules by 30%, shortens the production cycle, and improves production efficiency;

[0024] (3) The present invention uses a single film-forming material and adopts the above-mentioned drying and shaping scheme, so that the hollow capsules produced do not contain any gelling agent, and the drug dissolution performance is more stable;

[0025] (4) The use of high-viscosity cellulose in the present invention improves the toughness of the hollow capsule and reduces the water content of the hollow capsule. When the water content of the hollow capsule is as low as 2%, the capsule will not break;

[0026] (5) The present invention can realize the recovery of the annular capsule shell produced after the hollow capsule is cut, that is, the material head, thereby saving the cost of preparing the hollow capsule;

[0027] (6) The present invention can add pharmaceutical grade and food grade pigments, with the addition amount of 0-5.0%, to produce colored capsules. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the embodiments.

[0029] Example 1

[0030] Add 20 kg of 3.0 MPa.s hydropropyl methylcellulose, 75 kg of 6.5 MPa.s hydropropyl methylcellulose, and 5 kg of 50 MPa.s hydropropyl methylcellulose into the sol tank, then add 550 kg of 75°C purified water, start stirring at a speed of 25 r / min, and naturally cool to 50°C to form a transparent, bubble-free, and uniform glue solution.

[0031] The glue liquid is transferred to the fully automatic capsule production line installed with the 0# mold. After the process of dipping in glue, drying and shaping, fine drying, demoulding, cutting, fitting, demoulding, cutting, and fitting, transparent hydroxypropyl methylcellulose hollow capsules are obtained.

[0032] The drying and shaping parameters are set as follows: the compressed air pressure is 0.5 MPa, the flow rate of the compressed air is controlled to be 12 m / s, the compressed air drying time is 4 seconds, and the fine drying temperature is set to 45°C.

[0033] The moisture content of the hollow capsules off the machine is 2.4wt%.

[0034] Example 2

[0035] Add 35 kg of 3.0 MPa.s hydropropyl methylcellulose, 50 kg of 6.5 MPa.s hydropropyl methylcellulose, and 15 kg of 50 MPa.s hydropropyl methylcellulose into the sol tank, then add 600 kg of 75°C purified water, start stirring at a speed of 15 r / min, and naturally cool to 40°C to form a transparent, bubble-free, and uniform glue solution.

[0036] The glue liquid is transferred to the fully automatic capsule production line installed with the 0# mold. After the process of dipping in glue, drying and shaping, fine drying, demoulding, cutting, fitting, demoulding, cutting, and fitting, transparent hydroxypropyl methylcellulose hollow capsules are obtained.

[0037] The drying and shaping parameters are set as follows: the compressed air pressure is 0.5 MPa, the flow rate of the compressed air is controlled to be 15 m / s, the compressed air drying time is 5 seconds, and the fine drying temperature is set to 50°C.

[0038] The moisture content of the hollow capsules off the machine is 2.1wt%.

[0039] Example 3

[0040] Add 100 kg of material to the sol tank, then add 550 kg of 75°C purified water, start stirring at a speed of 25 r / min, and naturally cool to 45°C to form a transparent, bubble-free and uniform glue solution.

[0041] The glue liquid is transferred to the fully automatic capsule production line installed with the 0# mold. After the process of dipping in glue, drying and shaping, fine drying, demoulding, cutting, fitting, demoulding, cutting, and fitting, transparent hydroxypropyl methylcellulose hollow capsules are obtained.

[0042] The drying and shaping parameters are set as follows: the compressed air pressure is 0.5 MPa, the flow rate of the compressed air is controlled to be 12 m / s, the compressed air drying time is 4 seconds, and the fine drying temperature is set to 45°C.

[0043] The moisture content of the hollow capsules off the machine is 2.5wt%.

[0044] Example 4

[0045] Add 25 kg of 3.0 MPa.s methyl cellulose, 65 kg of 6.5 MPa.s hydroxyethyl cellulose, and 10 kg of 50 MPa.s hydroxyethyl methyl cellulose into the sol tank, then add 600 kg of 75°C purified water, start stirring at a speed of 18 r / min, and naturally cool to 45°C to form a transparent, bubble-free, and uniform glue solution.

[0046] The glue liquid is transferred to the fully automatic capsule production line installed with the 0# mold. After the process of dipping in glue, drying and shaping, fine drying, demoulding, cutting, fitting, demoulding, cutting, and fitting, transparent hydroxypropyl methylcellulose hollow capsules are obtained.

[0047] The drying and shaping parameters are set as follows: the compressed air pressure is 0.5 MPa, the flow rate of the compressed air is controlled to be 10 m / s, the compressed air drying time is 3 seconds, and the fine drying temperature is set to 30°C.

[0048] The moisture content of the hollow capsules off the machine is 5.4wt%.

[0049] Example 5

[0050] Add 20 kg of 3.0 MPa.s hydropropyl methylcellulose, 75 kg of 6.5 MPa.s hydropropyl methylcellulose, and 5 kg of 50 MPa.s hydropropyl methylcellulose into the sol tank, then add 550 kg of 75°C purified water, start stirring at a speed of 25 r / min, cool naturally to 50°C, then add 0.3 kg of food-grade lemon yellow pigment to form a yellow, bubble-free, uniform glue solution.

[0051] The glue liquid is transferred to the fully automatic capsule production line installed with the 0# mold. After the process of dipping in glue, drying and shaping, fine drying, demoulding, cutting, fitting, demoulding, cutting, and fitting, yellow hydroxypropyl methylcellulose hollow capsules are obtained.

[0052] The drying and shaping parameters are set as follows: the compressed air pressure is 0.5 MPa, the flow rate of the compressed air is controlled to be 13 m / s, the compressed air drying time is 4 seconds, and the fine drying temperature is set to 45°C.

[0053] The moisture content of the hollow capsules off the machine is 2.3wt%.

[0054] Comparative Example 1

[0055] Add 20 kg of 3.0 MPa.s hypromellose and 80 kg of 6.5 MPa.s hypromellose into the sol tank, but do not add 50 MPa.s hypromellose. Then add 550 kg of 75°C purified water, start stirring at a speed of 25 r / min, and naturally cool to 50°C to form a transparent, bubble-free, and uniform glue solution.

[0056] The glue liquid is transferred to the fully automatic capsule production line installed with the 0# mold. After the process of dipping in glue, drying and shaping, fine drying, demoulding, cutting, fitting, demoulding, cutting, and fitting, transparent hydroxypropyl methylcellulose hollow capsules are obtained.

[0057] The drying and shaping parameters are set as follows: the compressed air pressure is 0.5 MPa, the flow rate of the compressed air is controlled to be 10 m / s, the compressed air drying time is 3 seconds, and the fine drying temperature is set to 45°C.

[0058] The moisture content of the hollow capsules off the machine is 3.0 wt%.

[0059] The test data of each item of the obtained cellulose hollow capsules are shown in Table 1.

[0060] Table 1

[0061]

[0062]

[0063] Of course, the above contents are only preferred embodiments of the present invention and should not be considered as limiting the scope of the embodiments of the present invention. The present invention is not limited to the above examples. Equivalent changes and improvements made by ordinary technicians in this technical field within the essential scope of the present invention should all fall within the scope of the patent of the present invention.

Claims

1. A method for preparing a plant hollow capsule, characterized in that: The following steps are involved: (1) Weigh 100 parts of cellulose by weight, add 300-600 parts of purified water at or above 75°C, and stir until the cellulose is dissolved to form a cellulose glue; the cellulose is a mixture of three viscosities: 3.0 MPa.s, 6.5 MPa.s, and 50 MPa.s; the cellulose with a viscosity of 3.0 MPa.s accounts for 20-35% of the weight of the mixture, the cellulose with a viscosity of 6.5 MPa.s accounts for 50-75% of the weight of the mixture, and the cellulose with a viscosity of 50 MPa.s accounts for 5-15% of the weight of the mixture; (2) transferring the glue solution to the glue tank of the fully automatic capsule production line and dipping the glue at room temperature; (3) After the mold is dipped in the glue, it moves to the upper platform of the fully automatic capsule production line, and the capsule is dried and shaped using compressed air; the pressure of the compressed air is 0.5 MPa, the flow rate of the compressed air is controlled to be 10-15 m / s, and the drying time using the compressed air is 3-5 seconds; (4) After shaping, fine drying, demoulding, cutting, and fitting are completed on a fully automatic capsule production line to obtain the plant hollow capsules; the fine drying temperature is 30-50° C., and the water content of the hollow capsules produced is at least 2%; The cellulose is hydroxypropyl methylcellulose.

2. The method for preparing the plant hollow capsule according to claim 1, wherein: In step (1), during low-speed stirring, the stirring speed is controlled at 15-25 r / min, and the temperature of the cellulose glue is 35-50°C.

3. The method for preparing the plant hollow capsule according to claim 1, wherein: In step (3), during the drying and shaping process, the water loss of the glue on the mold is controlled at 50-60wt%.

4. The method for preparing the plant hollow capsule according to claim 1, wherein: In step (1), a pharmaceutical grade or food grade pigment is also added in an amount of 0-5.0 wt%.

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