JP7742381B2 - Tablet manufacturing method - Google Patents

Description

The present invention relates to a method for producing printed tablets.

Tablets are formed by compressing powder using a tablet press to a specified size and shape. Tablets formed in this way may have powder adhering to their surfaces. For example, Patent Document 1 discloses a powder removal device that includes a cover attached to a transport case that transports tablets discharged from a tablet press downstream, a spray device installed inside the cover, and a spray of high-pressure air that sprays onto the tablets inside the transport case, removing the powder from the tablet surface.

Japanese Patent Application Publication No. 11-290806

There was a concern that the powder removal device described in Patent Document 1 above may not be able to sufficiently remove powder from the surface of tablets. The inventors discovered that when printing is performed using ink on the surface of a tablet with powder adhering to it, the printed characters, symbols, or figures are particularly likely to be missing from the identification information.

The present invention aims to provide a method for manufacturing tablets that results in fewer defects in the identification information printed on the surface.

The present disclosure provides, for example, the following aspects:

[Aspect 1]
The tablet manufacturing method includes a conveying step and a printing step. The conveying step involves dropping the tablet from a pre-treatment step onto a conveying surface for conveying the tablet. The conveying step involves conveying the tablet. The conveying step includes a first suction step. The first suction step involves suctioning powder that has separated from the surface of the dropped tablet. The printing step involves printing on the surface of the tablet after the conveying step.

[Aspect 2]
In the tablet manufacturing method according to Aspect 1, the conveying step further includes a second suction step of sucking gas above the conveying surface from below the conveying surface.

[Aspect 3]
In the tablet manufacturing method according to Aspect 1 or Aspect 2, the printing step includes a third suction step in which the tablet is dropped from the conveying surface onto a printing conveying surface that conveys the tablet, and the third suction step in which powder separated from the surface of the tablet is sucked in before printing is performed on the surface of the tablet.

[Aspect 4]
In the tablet manufacturing method according to any one of Aspects 1 to 3, the printing step includes a powder removing step in which, before printing on the surface of the tablet, gas is blown onto a printing conveying surface that conveys the tablet in a direction opposite to the conveying direction, and powder that has separated from the surface of the tablet is sucked in.

[Aspect 5]
In the tablet manufacturing method according to any one of Aspects 1 to 4, the pre-treatment step includes a mixing step, a granulation step, and a tableting step. The mixing step involves mixing magnesium oxide particles with an internal additive to obtain a mixture. The internal additive includes cellulose and/or a cellulose derivative. The granulation step involves granulating the mixture to form granules. The tableting step involves tableting the granules.

[Aspect 6]
In the tablet manufacturing method according to Aspect 5, in the tableting step, an external additive is added in addition to the granules. The external additive includes cellulose and/or a cellulose derivative. The cellulose and/or the cellulose derivative includes crystalline cellulose having an average particle size of 50 μm or less.

[Aspect 7]
The tablet manufacturing apparatus includes a first conveying lane and a second conveying lane. The first conveying lane has a conveying surface for conveying the tablets located below the discharge outlet of a hopper containing a plurality of tablets. The first conveying lane has a suction port connected to the conveying surface onto which the tablets fall from the hopper and for sucking in gas. The second conveying lane conveys the tablets supplied from the first conveying lane in a conveying direction. The second conveying lane has a printing unit for printing on the surfaces of the tablets.

[Aspect 8]
In the tablet manufacturing apparatus according to Aspect 7, the first conveying lane has a vent hole formed therethrough in the thickness direction. The first conveying lane further has a second suction port. The second suction port is disposed on the opposite side of the conveying surface. The second suction port is connected to the vent hole and sucks gas from above the conveying surface.

[Aspect 9]
In the tablet manufacturing apparatus according to Aspect 7 or Aspect 8, the second conveying lane has a printing conveying surface that conveys the tablets and is disposed below the conveying surface of the first conveying lane. The second conveying lane has a third suction port. The third suction port is connected to the printing conveying surface onto which the tablets fall from the conveying surface of the first conveying lane and sucks in gas.

[Aspect 10]
In the tablet manufacturing apparatus according to any one of Aspects 7 to 9, the second conveying lane has a powder removal unit upstream of the printing unit from the printing conveying surface. The powder removal unit has a cover, a fourth suction port, and an outlet. The cover is provided facing the printing conveying surface. The fourth suction port and the outlet are provided on the cover. The fourth suction port and the outlet are arranged in order from upstream to downstream in the conveying direction. The fourth suction port sucks in gas. The outlet blows out gas. The outlet is open to the printing conveying surface in the opposite direction to the conveying direction.

The present invention makes it possible to obtain tablets with fewer defects in the identification information printed on their surfaces.

FIG. 1 is a front view schematically showing a manufacturing apparatus according to a first embodiment. 2A and 2B are diagrams illustrating a powder removal unit of the manufacturing apparatus according to the first embodiment, in which FIG. 2A is a plan view and FIG. 2B is a schematic front cross-sectional view. FIG. 2 is a schematic external view showing a tablet collection container of the manufacturing apparatus according to the first embodiment. FIG. 10 is a schematic explanatory view showing a bucket lifter and a tablet buffering chute of a manufacturing apparatus according to a second embodiment.

(First embodiment)
[Tablet manufacturing equipment]
A tablet manufacturing apparatus according to a first embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is a front view of the manufacturing apparatus according to the first embodiment, and Fig. 2 is a view of the powder removal unit of the manufacturing apparatus according to the first embodiment, in which Fig. 2(A) is a plan view and Fig. 2(B) is a front cross-sectional view.

As shown in FIG. 1, the manufacturing apparatus 10 comprises, in order from upstream to downstream in the conveying direction F, a hopper 12, a first conveying lane 14, a second conveying lane 16, and a recovery section 18. The hopper 12 contains a plurality of tablets 20 compressed in the pre-processing process. The hopper 12 has a discharge outlet 22 located vertically downward. The hopper 12 may have a feeder at the discharge outlet 22, although this is not shown.

The shape of the tablet 20 is not particularly limited. Examples of tablet 20 include disc, lenticular, and rod shapes. When the tablet 20 is disc-shaped or lenticular, the upper limit of the diameter can be 14 mm or less, or 10 mm or less, and the lower limit can be 5 mm or more, or 6 mm or more. Similarly, the upper limit of the thickness of the tablet 20 is not particularly limited. For example, the upper limit of the thickness of the tablet 20 can be 8 mm or less, or 7 mm or less, and the lower limit can be 3 mm or more, or 4 mm or more. Furthermore, the tablet 20 may have, for example, a cylindrical body and curved, convex cap portions at each axial end of the body. Furthermore, the shape of the tablet 20 in a plan view is not limited to a circular shape, and it may also be an elliptical or polygonal shape.

The first conveying lane 14 has a conveying surface 24 that conveys the tablets 20. The conveying surface 24 is positioned vertically below the discharge port 22. The first conveying lane 14 includes a connecting pipe 26, a first suction port 28 provided in the connecting pipe 26, a conveying body 30 having the conveying surface 24, and a second suction port 32 provided in the conveying body 30.

The connecting pipe 26 connects the discharge outlet 22 of the hopper 12 to the conveying surface 24. The connecting pipe 26 is positioned so that the tablets 20 contained in the hopper 12 can fall from the discharge outlet 22 through the connecting pipe 26 onto the conveying surface 24 under their own weight. One axial end of the connecting pipe 26 is connected to the discharge outlet 22 of the hopper 12. The other axial end of the connecting pipe 26 opens toward the conveying surface 24.

The first suction port 28 sucks gas between the connecting pipe 26 and the conveying surface 24. The first suction port 28 is a cylindrical member, and one axial end of the first suction port 28 is connected to the conveying surface 24 via the connecting pipe 26. The other axial end of the first suction port 28 is connected to the suction pump 34 via piping. In this specification, the phrase "connected to the conveying surface" means that the suction port is open toward the conveying surface 24 so that gas above the conveying surface 24 can circulate. "Connected to the conveying surface" means that the suction port may be in contact with or separated from the conveying surface 24. The first suction port 28 sucks gas from one end through the other end using the suction pump 34. In the case of Figure 1, the first suction port 28 is provided to penetrate the connecting pipe 26, and one end is disposed within the connecting pipe 26.

The conveying body 30 conveys the tablets 20 discharged from the hopper 12 through the connecting pipe 26. The conveying body 30 can be configured using, for example, a belt conveyor or a vibrating feeder. The conveying body 30 shown in FIG. 1 is a vibrating feeder that conveys the conveyed material in a linear direction by vibration. The conveying body 30 includes a receiving section 36 and a conveying section 38. The receiving section 36 is located vertically directly below the discharge outlet 22 of the hopper 12. The receiving section 36 receives the tablets 20 that drop from the discharge outlet 22 of the hopper 12. The conveying section 38 is located downstream of the receiving section 36 in the conveying direction F. The conveying section 38 has multiple air vents 40 formed in the conveying surface 24 that penetrate the thickness direction. The conveying section 38 can be made of, for example, a mesh, a punched metal, or a resin belt with through holes. The conveying section 38 may be inclined downward toward the downstream side. When the conveying body 30 is ejected from the hopper 12, powder may be generated from the surface of the tablet 20 due to the impact. The conveying body 30 conveys the tablet 20 and any powder that has separated from the surface of the tablet 20 on the conveying surface 24.

The second suction port 32 sucks powder on the conveying surface 24 away from the surface of the tablet 20. The second suction port 32 is arranged on the opposite side of the conveying body 30 from the conveying surface 24. The second suction port 32 is composed of a tubular member. One axial end of the second suction port 32 is connected to the air vent 40. The other axial end of the second suction port 32 is connected to the suction pump 34 via piping. The second suction port 32 sucks gas from one end through the other axial end by the suction pump 34. The second suction port 32 sucks gas downward from the conveying surface 24. In this embodiment, the second suction port 32 is connected to the air intake port 33. The air intake port 33 covers the opposite side of the conveying surface 24.

The second conveying lane 16 conveys the tablets 20 supplied from the first conveying lane 14 while removing powder from their surfaces. The second conveying lane 16 prints on the surfaces of the tablets 20. The second conveying lane 16 is arranged downstream of the first conveying lane 14 in the conveying direction F. The second conveying lane 16 includes a second conveying body 44. The second conveying body 44 has a printing conveying surface 42. The second conveying body 44 can be configured, for example, using a belt conveyor. The second conveying body 44 conveys the tablets 20 from upstream to downstream in the conveying direction F, passing through the second receiving section 46, the powder removal section 48, and the printing section 50, respectively. The second conveying body 44 conveys the printed tablets 20 to the collection section 18. The collection section 18 collects the conveyed tablets 20.

The print conveying surface 42 is positioned vertically below the conveying surface 24 of the first conveying lane 14. In other words, the print conveying surface 42 of the second receiving unit 46 is positioned below the conveying surface 24 on the downstream side of the first conveying lane 14.

The second receiver 46 removes powder that has detached from the surface of the tablet 20 due to the impact of dropping the tablet 20. The second receiver 46 has a third suction port 52 that sucks in gas from the print transport surface 42. The third suction port 52 is composed of a cylindrical member. The third suction port 52 has an opening at one axial end. One end of the third suction port 52 is positioned on the print transport surface 42, and the other axial end is connected to the suction pump 34. The third suction port 52 sucks in gas from one end through the other end using the suction pump 34. The second receiver 46 may have a receiver cover 54 that covers the print transport surface 42. In this embodiment, one end of the third suction port 52 is positioned perpendicular to the print transport surface 42. The third suction port 52 sucks in gas from the print transport surface 42 upward in the vertical direction.

The powder removal unit 48 removes powder remaining on the print conveying surface 42. The powder removal unit 48 has a cover 58 facing the print conveying surface 42, a fourth suction port 60, and an outlet 62. The powder removal unit 48 has the fourth suction port 60 and the outlet 62 provided on the cover 58. The fourth suction port 60 and the outlet 62 are arranged in order from upstream to downstream in the conveying direction F.

The cover 58 covers a predetermined area of the printing conveying surface 42 so as to retain gas in that area. As shown in Figures 2(A) and 2(B), the cover 58 has a covering portion 64 and a guide portion 66. The covering portion 64 is a plate-shaped member disposed opposite the printing conveying surface 42. In a plan view, the covering portion 64 has a tapered shape that protrudes toward the upstream side. In a front view, the covering portion 64 may have an inclined surface 68 that slopes downward from downstream to upstream. The guide portion 66 is plate-shaped and is integrally formed on the outer edge of the covering portion 64, protruding toward the printing conveying surface 42. As shown in Figure 2(B), a heightwise gap 70 that is shorter than the heightwise length of the tablet 20 is formed between the lower end of the guide portion 66 and the printing conveying surface 42. The guide portions 66 are provided on the outer edge of the covering portion 64 excluding at least the downstream end, i.e., on a pair of inclined upstream outer edges 72 on the upstream side and a pair of width-side outer edges 74 along the conveying direction F. As shown in FIG. 2(A), a widthwise gap 76 is formed between the cover 58 and the second conveying body 44 in the width direction, and the widthwise gap 76 is equal to or greater than the maximum length of one tablet 20 in a planar view. If the tablet 20 has a circular shape in a planar view, the maximum length of one tablet 20 in a planar view is the diameter of the tablet 20.

The fourth suction port 60 sucks gas trapped inside the cover 58 in the powder removal section 48. The fourth suction port 60 is composed of a cylindrical member. The fourth suction port 60 is located upstream of the cover 58. One axial end of the fourth suction port 60 is connected to the inside of the cover 58, and the other axial end is connected to the suction pump 34. The fourth suction port 60 sucks gas from one end through the other end using the suction pump 34. The number of fourth suction ports 60 is not limited to one as shown in Figure 2 (B). Two or more fourth suction ports 60 may be provided.

The blowout port 62 blows out gas, thereby stirring up any powder remaining on the print transport surface 42. The blowout port 62 is located downstream of the fourth suction port. In the cases of Figures 2(A) and 2(B), the blowout port 62 is located at the downstream end of the cover 58. The blowout port 62 is composed of a cylindrical member. One axial end of the blowout port 62 opens in the opposite direction to the transport direction F relative to the print transport surface 42. The other axial end of the blowout port 62 is connected to an air compressor (not shown) via piping (not shown). The blowout port 62 blows out gas from one end that is supplied to the other end from the air compressor. The blowout port 62 blows out gas toward the print transport surface 42. The number of blowout ports 62 is not limited to two, as shown in Figure 2(A). There may be one blowout port 62, or three or more blowout ports 62.

The printing unit 50 has, from upstream to downstream in the conveying direction F, an inspection camera 78 and a print head 80. The inspection camera 78 captures images of the surface of the tablet 20. The inspection camera 78 is not particularly limited, but may be, for example, a CCD (Charge Coupled Device) camera or a CMOS (Complementary Metal Oxide Semiconductor) camera. The print head 80 may be, for example, an inkjet type.

The following description will be given taking ink used in inkjet printing as an example.
For example, ink for inkjet printers contains a dye, water, ethanol, and a resin. The ink for inkjet printers may also contain other ingredients, such as a water-soluble high-boiling organic solvent, an emulsifier, a pH adjuster, a flavoring agent, and a preservative, as needed. It is preferable that all of the ink compositions are edible.

(dye)
The coloring matter can be one or more selected from synthetic food coloring matter and natural food coloring matter. Examples of synthetic food coloring matter include tar-based coloring matter, natural coloring derivatives, natural synthetic coloring matter, and titanium dioxide. Examples of tar-based coloring matter include Food Red No. 2, Food Red No. 3, Food Red No. 40, Food Red No. 102, Food Red No. 104, Food Red No. 105, Food Red No. 106, Food Yellow No. 4, Food Yellow No. 5, Food Green No. 3, Food Blue No. 1, Food Blue No. 2, Food Blue No. 1 Aluminum Lake, Food Red No. 2 Aluminum Lake, Food Red No. 3 Aluminum Lake, Food Red No. 40 Aluminum Lake, Food Yellow No. 4 Aluminum Lake, Food No. 5 Aluminum Lake, and Food Blue No. 2 Aluminum Lake. Examples of natural coloring matter derivatives include copper chlorophyll, copper chlorophyllin sodium, and norbixin potassium. Examples of natural synthetic pigments include β-carotene and riboflavin.

Natural food dyes include, for example, plant charcoal pigments, anthocyanin pigments, carotenoid pigments, quinone pigments, flavonoid pigments, betaine pigments, monascus pigments, and other pigments derived from natural sources. Examples of anthocyanin pigments include red radish pigment, red cabbage pigment, red rice pigment, elderberry pigment, cowberry pigment, gooseberry pigment, cranberry pigment, salmonberry pigment, perilla pigment, sweet blueberry pigment, strawberry pigment, dark sweet cherry pigment, cherry pigment, hibiscus pigment, huckleberry pigment, grape juice pigment, grape skin pigment, blackcurrant pigment, blackberry pigment, blueberry pigment, plum pigment, watermelon pigment, boysenberry pigment, mulberry pigment, purple sweet potato pigment, purple corn pigment, purple yam pigment, raspberry pigment, redcurrant pigment, loganberry pigment, and other anthocyanin pigments. Carotenoid pigments include annatto pigment, gardenia yellow, and other carotenoid pigments.Quinone pigments include cochineal pigment, lithospermum root pigment, lac pigment, and other quinone pigments.Flavonoid pigments include safflower yellow, sorghum pigment, onion pigment, and other flavonoid pigments.Betaine pigments include beet red pigment.Monascus pigments include monascus pigment and monascus yellow pigment.Other pigments derived from natural products include turmeric pigment, gardenia blue pigment, gardenia red pigment, and spirulina blue pigment.

The pigment content is preferably 0.1 to 10% by weight, and more preferably 0.5 to 8% by weight, of the total ink composition. If the pigment content of the ink is less than 0.1% by weight, the printed color tends to be pale and visibility tends to be poor. Furthermore, if the pigment content of the ink is more than 10% by weight, the ink viscosity increases, making it difficult for the ink to be ejected normally, resulting in poor printing.

(ethanol)
Preferred examples of ethanol include naturally brewed fermented ethyl alcohol and sugarcane alcohol. The ethanol content is preferably 5 to 60 wt %, more preferably 10 to 40 wt %, based on the total ink composition. If the ethanol content is less than 5 wt %, the ink tends to dry poorly. For example, if the ink takes more than 3 seconds to dry after printing, the ink may peel off or adhere to other tablets or conveyance surfaces during transport after printing, causing contamination. Furthermore, if the surface tension of the ink increases, the printed ink is more likely to be repelled by the tablet surface. In other words, the ink does not wet and spread on the tablet surface, making it difficult to dry, and the contact area with the tablet surface tends to be small, resulting in reduced adhesion. If the ink's adhesion is reduced, it may peel off when rubbed, even after 24 hours. Furthermore, if the ethanol content is greater than 60 wt %, the ink may dry and adhere to the ink within or around the inkjet nozzle opening. If the ink dries and blocks the openings, there is a risk that ejection defects or deviations in the flight direction of the ejected ink may occur. If ejection defects or deviations in the flight direction of the ink occur, printing defects may occur.

(Water-soluble high-boiling organic solvent)
The water-soluble high-boiling organic solvent can be used to prevent the nozzles of an inkjet head from drying out. Examples of the water-soluble high-boiling organic solvent include one or more selected from propylene glycol and glycerin. The content of the water-soluble high-boiling organic solvent is preferably 1 to 60 wt %, more preferably 2 to 55 wt %, based on the total ink composition. If the content of the water-soluble high-boiling organic solvent in the ink is less than 1 wt %, there is a risk of the ink drying out in the inkjet nozzles, resulting in poor printing. If the content of the water-soluble high-boiling organic solvent in the ink is more than 60 wt %, there is a tendency for the ink viscosity to become too high. If the ink viscosity is too high, there is a risk of the ink not being ejected properly, resulting in poor printing.

(resin)
If necessary, an edible resin may be added to the ink, such as one or more resins selected from the group consisting of shellac, gum arabic, starches, cellulose resins, vinyl acetate resins, and polyvinylpyrrolidone.

(emulsifier)
The emulsifier can be selected from one or more water-soluble emulsifiers selected from the group consisting of lecithin, glycerin fatty acid esters, sucrose fatty acid esters, sorbitan fatty acid esters, propylene glycol fatty acid esters, and polyoxyethylene sorbitan fatty acid esters. The emulsifier does not necessarily need to be incorporated into the ink. When incorporated into the ink, the emulsifier content is preferably 0.01 to 5 wt %, more preferably 0.1 to 2 wt %, based on the total ink composition. If the emulsifier content is less than 0.01 wt %, the ink surface tension tends to be too high. If the ink surface tension is too high, it may be difficult to achieve an appropriate meniscus state at the nozzle opening. If the ink does not achieve a meniscus state, the ink may not be ejected from the nozzle, or even if ejected, it may not land in the desired position, resulting in printing defects. Furthermore, if the emulsifier content is greater than 5 wt %, the ink may tend to thicken and precipitate over time. Ink may thicken or deposit, clogging the nozzles and causing printing defects.

(pH adjuster)
A pH adjuster can be added to adjust the solubility and stability of the resin contained in the ink. Examples of pH adjusters that can be added to adjust the ink to an acidic state include acetic acid and citric acid. Examples of pH adjusters that can be added to adjust the ink to an alkaline state include ammonium carbonate.

For stirring during ink preparation, a magnetic stirrer, propeller stirrer, or commonly used stirrer can be used, for example.

When preparing ink containing pigments such as vegetable charcoal pigments, titanium dioxide, and aluminum lake, it is preferable to disperse the pigment. This dispersion process can be carried out using a dispersing machine. Examples of dispersing machines include ball mills, roll mills, sand mills, and bead mills.

Ink can be filtered by, for example, centrifugal filtration or filter filtration.

In the tablet manufacturing method of this embodiment, tablets compressed in the pre-processing step can be fed into the hopper 12 shown in FIG. 1 using a tablet collection container 82 shown in FIG. 3. In other words, the tablet collection container 82 is configured to store tablets 20 compressed by a tablet press (not shown) and to feed the tablets 20 into the hopper 12. The tablet collection container 82 includes a container 84, a frame 86 that supports the container 84, and wheels 88 rotatably mounted on the frame 86. The container 84 has an inverted pyramid shape and a discharge outlet 90 on its bottom. The container 84 has a butterfly valve 92 at the discharge outlet 90. The frame 86 has support posts 93 whose upper ends are mounted at the four corners of the container 84, and connectors 94 that connect the lower ends of the support posts 93 together. The tablet collection container 82 has wheels 88 rotatably mounted on the lower ends of the support posts 93. The tablet collection container 82 stores the tablets 20 compressed by the tablet press in a container 84. The tablet collection container 82 then moves from the tableting process to the printing process and is positioned above the hopper 12. The tablet collection container 82 then opens a butterfly valve 92 and dumps the tablets 20 in the container 84 into the hopper 12 through the discharge port 90. Note that the container 84 is not limited to an inverted pyramid shape, but may also be an inverted cone shape.

[Tablet manufacturing method]
A tablet manufacturing method (hereinafter, sometimes simply referred to as a manufacturing method) to which the present invention is applied will be described below. In the first embodiment, a method for manufacturing tablets 20 using the manufacturing apparatus 10 of the first embodiment shown in Figures 1 and 2 will be described. In the following description, descriptions of configurations that overlap with the description of the manufacturing apparatus 10 will be omitted.

The manufacturing method of the first embodiment is a method of obtaining a printed tablet 20 by removing powder adhering to the surface of the tablet 20 from the tablet 20 and then printing on the surface of the tablet 20. That is, the manufacturing method of the tablet 20 of the first embodiment includes the following steps.
(1) A conveying process in which tablets 20 are dropped from a pre-processing process onto a conveying surface 24 for conveying the tablets 20, and the tablets 20 are conveyed. (2) A printing process in which printing is performed on the surface of the tablets 20 after the conveying process. (3) A first suction process in which powder that has separated from the surface of the dropped tablets 20 is sucked in during the conveying process. Furthermore, the conveying process (1) is described as including a second suction process (4) in which gas on the conveying surface 24 is sucked in from below the conveying surface 24.
Furthermore, the printing step (2) will be described as including the following steps.
(5) A third suction step in which the tablet 20 is dropped from the conveying surface 24 onto the printing conveying surface 42 that conveys the tablet 20, and powder that has separated from the surface of the tablet 20 is sucked in before printing is applied to the surface of the tablet 20. (6) A powder removal step in which, before printing is applied to the surface of the tablet 20, gas is blown onto the printing conveying surface 42 in the direction opposite to the conveying direction F, and powder that has separated from the surface of the tablet 20 is sucked in.The manufacturing method of the first embodiment further includes a printing processing step (7) in which printing is applied to the surface of the tablet 20 after the above steps (3) to (6).

The following explains each step in order. In the pre-processing step, a plurality of tablets 20 formed by tableting powder are stored in the hopper 12. First, in the conveying step (1), a plurality of tablets 20 are discharged from the discharge outlet 22 of the hopper 12. The discharged tablets 20 pass through the connecting pipe 26 due to their own weight and fall randomly onto the conveying surface 24 of the receiver 36. In addition to the tablets 20 coming into contact with other tablets 20 when discharged from the hopper 12, the impact they receive from the conveying surface 24 as they fall causes at least a portion of the powder adhering to the surface of the tablet 20 to detach from the surface of the tablet 20. The powder that detaches from the surface of the tablet 20 may fly up into the connecting pipe 26.

In the first suction step (3), the first suction port 28 sucks in the gas inside the connecting pipe 26 from one end, thereby sucking in the powder that has been stirred up inside the connecting pipe 26. Therefore, the manufacturing method according to the first embodiment can more efficiently remove powder from the tablets 20, thereby producing tablets 20 with less powder adhering to their surfaces.

The tablet 20 is then transported from the receiver 36 to the second transport lane 16 via the transport unit 38. Because the transport unit 38 is a vibrating feeder, the tablet 20 vibrates along with the transport unit 38. As a result, the tablet 20 is transported in the transport direction F, and at least a portion of the remaining powder adhering to the surface of the tablet 20 is detached from the surface of the tablet 20. The powder that has detached from the surface of the tablet 20 is transported in the transport direction F along with the tablet 20 on the transport surface 24.

In the second suction step (4), the second suction port 32 of the conveying section 38 sucks the gas on the conveying surface 24 from below the conveying surface 24 through the ventilation holes 40 formed in the conveying surface 24, thereby sucking in the powder on the conveying surface 24, particularly the powder present between the conveying surface 24 and the tablet 20. Therefore, the manufacturing method can prevent powder that has once detached from the surface of the tablet 20 from re-adhering to the surface of the tablet 20.

The tablet 20 is then transported from the first transport lane 14 to the second transport lane 16. In the printing process (2), the printing transport surface 42 of the second transport lane 16 is located below the transport surface 24 of the first transport lane 14, so the tablet 20 falls from the transport surface 24 to the printing transport surface 42 of the second receiver 46 due to its own weight. The impact of the falling tablet 20 on the printing transport surface 42 may cause at least a portion of the remaining powder adhering to the surface of the tablet 20 to detach from the surface of the tablet 20 and float up onto the printing transport surface 42 of the second receiver 46.

In the third suction step (5), the third suction port 52 sucks in the gas above the print conveying surface 42 of the second receiver 46, thereby sucking in the powder that has been blown up onto the print conveying surface 42 of the second receiver 46. Therefore, the manufacturing apparatus 10 of the first embodiment can more efficiently remove powder from the tablets 20. By providing the receiver cover 54, the second receiver 46 can prevent the blown up powder from scattering, allowing the powder to be more reliably sucked in from the third suction port 52.

The tablet 20 is then transported to the powder removal section 48. In the powder removal step (6), the tablet 20 that reaches the powder removal section 48 comes into contact with the guide section 66 of the cover 58, because the height gap 70 is shorter than the height length of the tablet 20. This causes the tablet 20 to move in the width direction of the print conveying surface 42 and pass between the cover 58 and the second conveying body 44 in the width direction. In other words, the tablet 20 does not enter the cover 58 through the height gap 70, and does not pass between the cover 58 and the print conveying surface 42.

The blowing port 62 blows gas toward the printing conveying surface 42 in the direction opposite to the conveying direction F. The gas blown toward the printing conveying surface 42 in the direction opposite to the conveying direction F causes powder on the printing conveying surface 42 to float up from the printing conveying surface 42. As a result, the powder rises above the printing conveying surface 42 along with the blown gas, and some of the raised powder collides with the surface of the covering portion 64 facing the printing conveying surface 42, causing the raised powder to remain within the cover 58. The fourth suction port 60 sucks in the gas within the cover 58, i.e., between the covering portion 64 and the printing conveying surface 42, thereby sucking in the powder that has risen above the printing conveying surface 42 and remained within the cover 58. Therefore, by separating the tablet 20 from the powder adhering to the printing conveying surface 42 and sucking in the powder adhering to the printing conveying surface 42, the manufacturing apparatus 10 can prevent powder that has detached from the surface of the tablet 20 from re-adhering to the surface of the tablet 20.

The powder removal unit 48 moves the tablets 20 outward in the width direction of the printing conveying surface 42, forming an area on the inside of the printing conveying surface 42 in the width direction through which the tablets 20 do not pass. The gas blown out in the direction opposite to the conveying direction F onto the printing conveying surface 42 is blown onto the printing conveying surface 42 through which the tablets 20 do not pass, and therefore does not interfere with the conveyance of the tablets 20. Therefore, the manufacturing apparatus 10 can efficiently remove powder without reducing conveyance efficiency. The covering unit 64 has an inclined surface 68 that slopes downward from downstream to upstream in a front view, thereby returning powder that collides with the surface of the covering unit 64 on the printing conveying surface 42 side to the downstream side. Therefore, the manufacturing apparatus 10 can more efficiently remove powder from the printing conveying surface 42.

The tablet 20 that has passed through the powder removal unit 48 is then transported to the printing unit 50 by the second transport body 44. In the printing process (7), the inspection camera 78 photographs the surface of the tablet 20. Based on the photographed image, the manufacturing apparatus 10 detects, for example, the position and orientation of the tablet 20 and prints on the surface of the tablet 20 using the print head 80 according to the position of the tablet 20. The printed tablet 20 is transported further downstream by the second transport body 44 and collected in the collection unit 18. The manufacturing apparatus 10 according to the first embodiment efficiently removes powder from the surface of the tablet 20 before printing, thereby producing tablets 20 that are less likely to have printing defects in the identification information, such as missing characters.

[Action and effect]
As described above, the manufacturing method of the first embodiment includes a conveying step (1) in which tablets 20 are dropped from a pre-processing step onto a conveying surface 24 for conveying the tablets 20, and a printing step (2) in which printing is performed on the surfaces of the tablets 20 after the conveying step (1). The method also includes a first suction step (3) in which powder that has separated from the surface of the dropped tablets 20 is sucked in the conveying step (1). In the conveying step (1), tablets 20 are dropped from the hopper 12 of the pre-processing step onto the conveying surface 24, and powder that has separated from the surface of the tablets 20 due to the impact of the drop is sucked in the first suction step (3), thereby more efficiently removing powder from the tablets. Therefore, this manufacturing method can produce tablets 20 with less powder adhering to the surface. Furthermore, according to this manufacturing method, since printing is performed in the printing step (2) on the surfaces of the tablets 20 that have undergone the conveying step (1), tablets with fewer printing defects of identification information, such as missing characters, can be obtained.

The tablet manufacturing apparatus 10 of the first embodiment also includes a first conveying lane 14, which has a conveying surface 24 for conveying the tablets 20, located below the discharge outlet 22 of a hopper 12 containing multiple tablets 20, and a second conveying lane 16 for conveying the tablets 20 supplied from the first conveying lane 14 in the conveying direction F. The first conveying lane 14 has a first suction port 28 connected to the conveying surface 24 onto which the tablets 20 fall from the hopper 12 and which draws in gas. The second conveying lane 16 is configured to have a printing unit 50 that prints on the surface of the tablets 20. As described above, this allows the tablets 20 to be dropped onto the conveying surface 24 from the hopper 12 in the pre-processing step, and powder that has detached from the surface of the tablets 20 due to the impact of the drop can be more efficiently removed from the tablets 20 by suctioning it through the first suction port 28. Therefore, the present manufacturing apparatus 10 can manufacture tablets 20 with less powder adhering to their surfaces. Furthermore, with this manufacturing device 10, the printing unit 50 prints on the surfaces of the tablets 20 from which powder has been removed in the first conveying lane 14, resulting in tablets 20 that are less likely to have printing defects in the identification information, such as missing characters.

[Modification]
The present invention is not limited to the above embodiment and can be modified as appropriate within the scope of the present invention. For example, the number of first suction ports 28, second suction ports 32, and third suction ports 52 is not particularly limited and may be one, two, or more. Furthermore, the first suction ports 28, second suction ports 32, and third suction ports 52 are not limited to cylindrical members, and may also be rectangular cylindrical members.

In the first embodiment, the first suction port 28 is described as being provided in the connecting pipe 26, but the present invention is not limited to this. One end of the first suction port 28 may be disposed between the lower end of the connecting pipe 26 and the conveying surface 24.

In the first embodiment, one end of the second suction port 32 is connected to an air intake port covering the opposite side of the conveying surface 24 having the ventilation holes 40, but the present invention is not limited to this. For example, one end of the second suction port 32 may have a linear opening extending along the width direction of the conveying body 30, and may be configured to suck in gas from above the conveying surface 24 through some of the ventilation holes 40 formed in the conveying surface 24 that are aligned in the width direction of the conveying body 30.

In the first embodiment, one end of the third suction port 52 is located on the print conveying surface 42 and is arranged perpendicular to the print conveying surface 42, but the present invention is not limited to this. For example, one end of the third suction port 52 may be located on the print conveying surface 42 and tilted at a predetermined angle within a range of less than ±90 degrees in the width direction and less than ±90 degrees in the conveying direction relative to the perpendicular direction of the print conveying surface 42. Furthermore, as long as one end of the third suction port 52 is connected to the print conveying surface 42, it may be located outside the conveying direction F of the conveying body 30 in a direction perpendicular to the vertical direction (hereinafter also referred to as the "width direction").

In the first embodiment, the cover 58 of the powder removal unit 48 is described as having a guide portion 66, but the present invention is not limited to this, and the cover 58 does not need to have a guide portion 66. If the cover 58 does not have a guide portion 66, the tablets 20 on the print conveying surface 42 pass between the powder removal unit 48 and the print conveying surface 42, and are conveyed while moving against the gas blown out from the outlet 62. By being exposed to the gas blown out from the outlet 62, powder adhering to the surface of the tablets 20 is more reliably removed from the surface of the tablets 20 and sucked in by the fourth suction port 60.

In the first embodiment, a single powder removal unit 48 is provided on the print conveying surface 42, but the present invention is not limited to this. For example, multiple powder removal units 48 may be provided in the width direction perpendicular to the conveying direction F, or multiple units may be provided along the conveying direction F, or they may be provided randomly, such as in a staggered pattern.

In the first embodiment, the outlet 62 blows gas in the direction opposite to the conveying direction F, but the present invention is not limited to this. For example, in addition to the outlet 62 that blows gas in the direction opposite to the conveying direction F, the manufacturing apparatus 10 may also have at least one of an outlet that blows gas in the forward direction relative to the conveying direction F and an outlet that blows gas in a direction intersecting the conveying direction F.

Second Embodiment
Next, a manufacturing apparatus 10A according to a second embodiment will be described with reference to Fig. 4. The manufacturing apparatus 10A according to the second embodiment differs from the manufacturing apparatus 10 according to the first embodiment in the mechanism from collecting the tablets 20 compressed by the tablet press 110 to feeding them into the hopper 12. The manufacturing apparatus 10A according to the second embodiment includes a bucket lifter 96 and a tablet buffer chute 98. For ease of explanation, Fig. 4 shows a schematic partial cross section of the tablet buffer chute 98 and the hopper 12. In the manufacturing apparatus 10A according to the second embodiment, the bucket lifter 96 and the tablet buffer chute 98 are arranged between the tablet press 110 and the hopper 12.

The bucket lifter 96 has a tower 100, a bucket 102, and a lifting mechanism 104. The tower 100 extends vertically. The tower 100 has a receiving port 106 and a supply port 108. The receiving port 106 receives tablets 20 from a tablet press 110. The receiving port 106 is a tubular member that spans from the lower end of the tower 100 to the tablet press 110. The supply port 108 supplies tablets 20 to the tablet buffer chute 98. The supply port 108 is a tubular member that extends from the upper end of the tower 100 toward the tablet buffer chute 98.

The bucket 102 is disposed within the tower 100. The bucket 102 has an internal space 112 for storing tablets 20, and a receiving port 114 and a supply port 116 that communicate with the internal space 112. The bucket 102 can be moved vertically within the tower 100 by the lifting mechanism 104. When the bucket 102 is positioned at the lower end within the tower 100, the receiving port 114 is connected to the receiving port portion 106. When the bucket 102 is positioned at the upper end within the tower 100, the supply port 116 is connected to the supply port portion 108.

The lifting mechanism 104 moves the bucket 102 vertically upward and downward within the tower 100. The lifting mechanism 104 may be configured, for example, by an actuator powered by air pressure. The lifting mechanism 104 may also be configured, for example, by a chain mechanism powered by a motor.

The tablet buffer chute 98 is positioned between the supply port 108 and the hopper 12. In the manufacturing apparatus 10A according to the second embodiment, the tablet buffer chute 98 is positioned in the center of the hopper 12. The tablet buffer chute 98 has a cylindrical portion 118, a second outlet 120, and a fifth suction port 122. The cylindrical portion 118 is a cylindrical member with an opening along the vertical direction. The cylindrical portion 118 has a sliding portion 124 on its inner surface as a buffer material. The sliding portion 124 has a spirally curved surface and extends from the upper end to the lower end of the cylindrical portion 118.

The second outlet 120 is located below the vertical center of the cylindrical portion 118. In the manufacturing apparatus 10A according to the second embodiment, two second outlets 120 are provided. The number of second outlets 120 may be one, three, or more. The second outlet 120 is a cylindrical member with one axial end opening into the interior of the cylindrical portion 118 and the other axial end connected to an air compressor via piping (not shown). The fifth suction port 122 is located vertically above the second outlet 120, preferably above the vertical center of the cylindrical portion 118. Multiple fifth suction ports 122 may be provided. The fifth suction port 122 is a cylindrical member with one axial end opening into the interior of the cylindrical portion 118 and the other axial end connected to the suction pump 34 via piping.

Tablets 20 compressed by the tablet press 110 are supplied into the tower 100 through the receiving port 106. The tablets 20 pass through the receiving port 106 and are stored in the internal space 112 of the bucket 102 via the receiving port 114. When a certain amount of tablets 20 has been stored in the internal space 112, the bucket 102 is moved to the upper end of the tower 100 by the lifting mechanism 104. Once the bucket 102 reaches the upper end of the tower 100, it supplies tablets 20 from the supply port 116 to the supply port 108. The tablets 20 supplied to the supply port 108 move downward from the opening at the upper end of the tablet buffer chute 98, sliding along the sliding portion 124. Once the tablets 20 reach the lower end of the tablet buffer chute 98, they fall into the hopper 12.

The second outlet 120 blows gas toward the inside of the cylindrical portion 118. The gas blown toward the inside of the cylindrical portion 118 causes the powder on the sliding portion 124 to float from the surface of the sliding portion 124. As a result, the powder floats upward within the cylindrical portion 118 along with the blown gas. The fifth suction port 122 sucks in the gas within the cylindrical portion 118, thereby preventing powder that has detached from the surface of the tablet 20 from adhering to the surface of the tablet 20 again.

The manufacturing apparatus 10A according to the second embodiment uses a bucket lifter 96 to continuously feed tablets 20 into the hopper 12. Compared to the first embodiment, in which the tablet collection container 82 is moved, the manufacturing apparatus 10A can reduce the vibrations applied to the tablets 20. Therefore, the manufacturing apparatus 10A according to the second embodiment can further reduce the generation of powder from the tablets 20.

Tablets 20 supplied to the tablet buffer chute 98 slide along the sliding portion 124 and move downward while spirally circling the inner surface of the cylindrical portion 118. In other words, the tablet buffer chute 98 can reduce the impact on the tablets 20 when they are dropped into the hopper 12. As a result, the manufacturing apparatus 10A according to the second embodiment can temporarily store tablets 20 within the hopper 12 and further suppress the generation of powder within the hopper 12.

(Third embodiment)
Next, an embodiment of a tablet manufactured by the above-described manufacturing apparatus will be described. The tablet according to the third embodiment can be manufactured by the manufacturing method and manufacturing apparatus according to the first and second embodiments. The tablet according to the third embodiment contains magnesium oxide, which will be described later as an active ingredient. It has been found that such tablets tend to have a particularly large amount of powder adhering to their surface immediately after tableting. More specifically, the tablet according to the third embodiment contains granules containing magnesium oxide particles and an internal additive. The tablet preferably further contains granules and an external additive. Furthermore, the tablet more preferably contains, for example, cellulose and/or a cellulose derivative as an internal additive and/or an external additive. It is more preferable that the tablet has a mass ratio of [cellulose and/or cellulose derivative contained as an internal additive]:[cellulose and/or cellulose derivative contained as an external additive] within a certain range. The above-described tablet can achieve both reduced tablet friability and a reduced incidence of capping. The manufacturing apparatus and manufacturing method according to the third embodiment are suitable for the above-described tablet. That is, by applying the manufacturing apparatus and manufacturing method according to the third embodiment to the above-mentioned tablets, tablets with less powder adhering to the surface can be obtained.

The tablet may contain, as an external additive, crystalline cellulose having an average particle size of 50 μm or less. When crystalline cellulose having an average particle size of 50 μm or less is added as an external additive, there is a tendency for the amount of powder adhering to the tablet surface to increase, compared to when an external additive with a larger particle size is added. According to this manufacturing method, the powder can be efficiently removed, resulting in tablets with less powder adhering to the tablet surface.

[Wearability]
In the third embodiment, "friability" refers to, for example, an index of the abrasion and brittleness of a tablet against impact, and can be measured by the method described in "Reference Information - Tablet Friability Test Method, 17th Edition of the Japanese Pharmacopoeia." Specifically, for a number of tablets weighing approximately 6.5 g, a tablet friability meter (Toyama Sangyo Co., Ltd., tablet friability tester TFT-1200) is used to abrade test tablets at 100 revolutions (24 to 26 revolutions per minute), the initial tablet mass before abrasion and the tablet mass after abrasion are measured, and the friability can be determined by calculating the friability according to the following formula 1.

When the above measurement method is used, the upper limit of the friability range for the tablet of the third embodiment should be less than 0.40%, with less than 0.35% and even less than 0.30% being preferred. On the other hand, the lower the friability, the more desirable it is, so no lower limit is set.

[Capping]
In the third embodiment, "capping" refers to the peeling off of the upper or lower surface of a tablet as a cross-sectional piece. "Capping" occurs, for example, due to impact during tablet compression, transportation, or packaging in the tablet manufacturing process. The capping incidence rate can be determined by a cassette rotor test. The capping incidence rate can be calculated according to the following formula 2. More specifically, the capping incidence rate is determined by discharging tablets from a cassette rotor set at a height of 2 m and counting the number of capped tablets among the dropped tablets. The capping incidence rate is determined by testing a sufficient number of test tablets, for example, 100 tablets. The capping incidence rate is calculated by counting the number of tablets that have capped out of the 100 test tablets tested, and calculating the percentage. For example, a cassette rotor for Magmit 500 mg tablets manufactured by TOSHO can be used. When calculating the capping incidence rate, the flooring specifications used can be a concrete trowel + epoxy floor coating + paste construction method (thickness 2 mm) (ABC Shokai) Chemicrete E or equivalent product specifications.

When the above measurement method is used, the range of the capping incidence rate for tablets of the third embodiment is preferably less than 12%, more preferably less than 11%, and even more preferably less than 10%. However, since the lower the capping incidence rate, the more desirable it is, no lower limit is set.

[hardness]
In the third embodiment, "hardness" refers to an index of tablet hardness, which can be measured with a tablet hardness tester. The tablet hardness tester that can be used is the DC-50 manufactured by Okada Seiko Co., Ltd. The hardness can be determined, for example, by measuring the tablet hardness in the diameter direction using a tablet hardness tester. If the tablet hardness is too low, the friability increases, so the lower limit is preferably 30 N or more, more preferably 40 N or more, and even more preferably 50 N or more. On the other hand, from the viewpoint of powder generation, the higher the tablet hardness, the more desirable it is, so no upper limit is particularly set.

[Collapse time]
In the third embodiment, "disintegration time" is an index of the ease with which a tablet disintegrates in a solution. Disintegration time can be measured according to the General Test Method/Disintegration Test Method in the Seventeenth Edition of the Japanese Pharmacopoeia. Disintegration time can be measured using a disintegration tester. More specifically, the "disintegration time" is measured by measuring the disintegration time in water using a disintegration tester for an appropriate number of test tablets, for example, six tablets, as a test solution. As a disintegration tester, for example, the NT-20HS disintegration tester manufactured by Toyama Sangyo Co., Ltd. can be used. For tablets, an appropriate disintegration time is preferable because it provides tablets that disintegrate in the oral cavity in a short time upon ingestion and are easy to swallow. The upper limit of an appropriate disintegration time is 20 seconds or less, preferably 15 seconds or less, and more preferably 11 seconds or less. There is no particular restriction on the lower limit, but it is usually 0.5 seconds or more, or 1 second or more.

[Cellulose and/or cellulose derivatives]
In the third embodiment, "cellulose" refers to a linear polymer represented by (C6H10O5)n in which β-glucose molecules are linearly polymerized via glycosidic bonds, and examples include crystalline cellulose, microcrystalline cellulose, and powdered cellulose. "Cellulose derivatives" refer to cellulose molecules in which different substituents have been introduced into hydroxy groups via ether or ester bonds, and examples include methyl cellulose, ethyl cellulose, carboxymethyl cellulose, calcium carboxymethyl cellulose, sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, and low-substituted hydroxypropyl cellulose. "Cellulose and/or cellulose derivatives" as defined in the third embodiment refers to at least one selected from the above-mentioned "cellulose" and "cellulose derivatives." Low-substituted hydroxypropyl cellulose refers to cellulose in which an extremely small number of hydroxypropoxy groups have been introduced into the glucose ring, i.e., cellulose with a low level of O-(2-hydroxypropyl) molar substitution of 0.2 to 0.4. Such cellulose derivatives may be in the form of, for example, powder, particles, or fine particles.

Cellulose and/or cellulose derivatives may be synthesized or commercially available. Commercially available products include crystalline cellulose such as various grades of CEOLUS (registered trademark) from Asahi Kasei Corporation, such as CEOLUS (registered trademark) PH-101, UF-711, PH-102, PH-200, PH-301, PH-302, PH-20JP, UF-702, KG-802, and KG-1000.

[Magnesium oxide particles]
The magnesium oxide particles used in the third embodiment are particles of magnesium oxide (MgO). The magnesium oxide particles used in the third embodiment can be obtained by calcining magnesium hydroxide particles. For example, they can be obtained by calcining magnesium hydroxide having an average particle size of 1 to 10 μm as measured by a laser diffraction scattering method at 600 to 1000°C. The magnesium oxide particles may be synthesized or commercially available. For example, heavy grade magnesium oxide manufactured by Kyowa Chemical Industry Co., Ltd., powder grade magnesium oxide manufactured by Konoshima Chemical Co., Ltd., or light grade and heavy grade magnesium oxide manufactured by Tomita Pharmaceutical Co., Ltd., as stipulated in the Japanese Pharmacopoeia, can be used.

The magnesium oxide particles used in the third embodiment may be in either powder or granular form, but granular form is more effective in preventing wear on the tablet press and also allows for the production of high-content tablets with better shape retention stability.

The magnesium oxide particles used in the third embodiment are not limited, but may preferably have a predetermined particle size. For example, the upper limit of the average particle size of the magnesium oxide particles measured by laser diffraction scattering can typically be set to 40 μm or less, or 20 μm or less, or 10 μm or less. By setting the average particle size of the magnesium oxide particles to the above-mentioned upper limit or less, the suspended particle size at the time of tablet disintegration can be reduced, which may result in a tablet with less roughness in the oral cavity. On the other hand, the lower limit of the average particle size is not limited, but can typically be set to 0.25 μm or more, or 0.5 μm or more, or 1 μm or more, for example, in consideration of manufacturing limitations and cost-effectiveness.

The average particle size and average particle diameter of the magnesium oxide particles of the third embodiment and the magnesium hydroxide particles that are their raw material can be measured using a measuring device that employs the laser diffraction scattering method. The measuring device that employs the laser diffraction scattering method can be, for example, a particle size distribution measuring device, model MT3300EX2, manufactured by Microtrackbell Co., Ltd.

If the bulk density of the magnesium oxide particles used in the third embodiment is too high, it may cause a decrease in hardness, so the upper limit can be set to 0.8 g/mL or less, or 0.7 g/mL or less. On the other hand, if the bulk density is too low, it may cause capping and lamination, so the lower limit can be set to 0.1 g/mL or more, or 0.2 g/mL or more. The bulk density can be measured, for example, using a 100 mL stainless steel cup (actual measured mass (g)/100 (mL)).

If the angle of repose of the magnesium oxide particles used in the third embodiment is too large, it may lead to poor flowability and variation in tablet weight during tableting, so the upper limit can be set to 50° or less, or 48° or less. On the other hand, the lower the angle of repose, the more desirable it is, so no lower limit is set. The angle of repose can be measured, for example, using a Multitester MT-1 manufactured by Seishin Enterprise Co., Ltd.

[tablet]
One aspect of the third embodiment is a tablet containing magnesium oxide as an active ingredient. The tablet of the third embodiment includes granules containing magnesium oxide particles and an internal additive. The tablet of the third embodiment may include an external additive added to the granules. The tablet of the third embodiment may include at least cellulose and/or a cellulose derivative as the internal additive and/or the external additive. The tablet of the third embodiment has a mass ratio of [cellulose and/or cellulose derivative contained as an internal additive]:[cellulose and/or cellulose derivative contained as an external additive] within a certain range.

The magnesium oxide particles are preferably contained in the granules together with the internal additive. If the magnesium oxide particle content is too high, moldability may be insufficient, so it can be set to, for example, 90% by mass or less, or 88% by mass or less, relative to the entire tablet. On the other hand, if the magnesium oxide particle content is too low, it is possible to incorporate additives with high compressibility and plastic deformability, resulting in a tablet with high moldability, but the cost per tablet will increase. Therefore, it is preferable to set the magnesium oxide particle content to, for example, 80% by mass or more, or 85% by mass or more, relative to the entire tablet.

The tablet of the third embodiment has a mass ratio of [cellulose and/or cellulose derivatives contained as internal additives] to [cellulose and/or cellulose derivatives contained as external additives] within a certain range. By increasing the proportion of external additives, tablets can be expected to have increased hardness and reduced friability. Increasing the proportion of external additives too much can result in, for example, an increased incidence of capping and decreased tube passability. Therefore, the mass ratio of cellulose and/or cellulose derivatives contained as external additives, assuming the mass of the cellulose and/or cellulose derivatives contained in the entire tablet as 100, is preferably set at an upper limit of 90 or less, e.g., 88 or less, 85 or less, 80 or less, or 75 or less, and preferably at a lower limit of more than 20, e.g., 21 or more, 22 or more, 23 or more, 24 or more, or 25 or more. On the other hand, if the proportion of internal additives contained in a tablet is too low, compaction will be insufficient, resulting in the generation of many fine particles and the tendency for air to be trapped. This air may not be completely removed during subsequent tableting, potentially resulting in capped tablets. Therefore, tablets require the incorporation of a certain amount of internal additives. However, if the proportion of internal additives is too high, compacted granules are obtained by granulation, making the granules less susceptible to destruction by further compaction during tableting. If the granules become less susceptible to destruction by further compaction during tableting, the tablet's moldability, i.e., its friability, increases. Therefore, the mass ratio of the internal additives contained in the tablet is preferably set to an upper limit of less than 80, where the mass of the cellulose and/or cellulose derivatives contained in the entire tablet is taken as 100. More preferably, the mass ratio of the internal additives contained in the tablet is set to an upper limit of 79 or less, 78 or less, 77 or less, 76 or less, or 75 or less, where the mass of the cellulose and/or cellulose derivatives contained in the entire tablet is taken as 100. The mass ratio of the internal additives contained in the tablet is preferably set to a lower limit of 10 or more, e.g., 12 or more, 15 or more, 20 or more, or 25 or more, where the mass of the cellulose and/or cellulose derivatives contained in the entire tablet is taken as 100.

Furthermore, since the cost per tablet increases if the content of cellulose and/or cellulose derivatives in the entire tablet is too high, it can be set to 20% by mass or less, 15% by mass or less, or 12% by mass or less of the entire tablet. On the other hand, since the effects of the present invention may not be achieved if the content is too low, it can be set to 5% by mass or more, 7% by mass or more, or 9% by mass or more of the entire tablet.

In the tablet of the third embodiment, the cellulose and/or cellulose derivative defined above is preferably used as an excipient or binder in both the internal additive and the external additive. Furthermore, the cellulose and/or cellulose derivative contained in the internal additive and the external additive may be the same or different.

In the third embodiment, the internal additive refers to an additive containing one or more substances added to and mixed with the active ingredient before the granulation process in tablet production. Other additives may be added as internal additives in addition to the cellulose and/or cellulose derivatives defined above. In particular, to adjust the preferred disintegration time as described above, it is preferable to add a disintegrant such as croscarmellose sodium, corn starch, carmellose calcium, crospovidone, or carboxystarch sodium as an internal additive in addition to the cellulose and/or cellulose derivatives contained in the internal additive and external additive at the specific ratio defined above. Disintegrants may be synthesized or commercially available. Examples of commercially available disintegrants include Kiccolate (registered trademark) ND-2HS manufactured by Nichirin Chemical Industry Co., Ltd. Because tablet molding may be difficult, the upper limit may be set to, for example, 5% by mass or less, or 3.5% by mass or less, based on the total tablet. On the other hand, because a too small amount may make disintegration difficult, the lower limit may be set to, for example, 1% by mass or more, or 2% by mass or more, based on the total tablet.

In the third embodiment, the external additive refers to an additive containing one or more substances that are added to the granules produced after the granulation process during tablet production and compressed together with the granules. In addition to the cellulose and/or cellulose derivatives contained in the internal additive and the external additive at the specific ratios defined above, other additives may also be added as external additives. In particular, from the perspective of achieving the intended effect of the present invention, the addition of a lubricant is preferred. Examples of lubricants include stearic acid and its salts (Mg and Ca salts). Stearates are preferred, with magnesium stearate and calcium stearate being more preferred. Since too much lubricant can delay disintegration, the upper limit can be set to, for example, 2% by mass or less, 1.5% by mass or less, or 1.0% by mass or less of the total tablet. On the other hand, since too little lubricant can cause adhesion to punches and dies, the lower limit of the amount of lubricant added to the total tablet can be set to, for example, 0.2% by mass or more, 0.5% by mass or more, or 0.9% by mass or more.

The mass of the tablet of the third embodiment, which contains magnesium oxide as an active ingredient, can be, for example, up to 1000 mg, 800 mg, or 600 mg per tablet. The lower limit of the mass of the tablet of the third embodiment can be 10 mg or more, 50 mg or more, or 100 mg or more.

The tablet of the third embodiment is orally administered as a pharmaceutical for humans or animals, for example, for antacid, laxative, and prevention of urinary calcium oxalate stones. It can also be used as a supplement for humans or animals for magnesium supplementation and antihypomagnesemia, for example. The dosage varies depending on the application, purpose, and condition. For example, when used as an antacid, an adult typically administers 0.5 to 1.0 g per day in divided doses in magnesium oxide equivalent. When used as a laxative, an adult typically administers 2 g per day in divided doses in magnesium oxide equivalent, either three times a day before or after meals, or once before bedtime. When used to prevent urinary calcium oxalate stones, an adult typically administers 0.2 to 0.6 g per day in magnesium oxide equivalent, orally with plenty of water. For other uses, magnesium is typically taken within the tolerable upper limit of intake. For example, the US dietary reference intake for magnesium intake from sources other than regular foods is set at 350 mg per day for healthy adults and 5 mg per kg of body weight per day for healthy children (Institute of Medicine (IOM). Food and Nutrition Board. "Dietary Reference Intakes: Calcium, Phosphorus, Magnesium, Vitamin D and Fluoride". Washington, DC: National Academy Press, 1997).

The pharmaceutical product of the third embodiment has been approved in Japan for use as an antacid, laxative, and for preventing the formation of urinary calcium oxalate stones, using the active ingredient as desired. The internal additive and/or external additive may further contain one or more other optional ingredients, as long as they do not substantially interfere with the desired effects in each application, as well as the reduction in friability and the reduction in the incidence of capping. Such other ingredients include, but are not limited to, various pharmaceutically acceptable pharmaceutical additives, such as colorants and flavoring agents. Any one of these ingredients may be used alone, or two or more may be used in any combination and ratio.

The above-mentioned tablets can be produced, for example, by the following pretreatment method: a method for producing tablets containing magnesium oxide as an active ingredient, which comprises mixing magnesium oxide particles with an internal additive containing cellulose and/or a cellulose derivative;
granulating the mixture to form granules;
adding an external additive containing cellulose and/or a cellulose derivative to the granules and tableting the granules;
The mass ratio of [cellulose and/or cellulose derivative contained as an internal additive]:[cellulose and/or cellulose derivative contained as an external additive] is within the range of 75:25 to 10:90.

First, magnesium oxide particles, cellulose and/or a cellulose derivative, and optionally an internal additive containing one or more other ingredients are mixed together.
The resulting mixture is then granulated to form granules. In view of the ingredients of the tablet of the third embodiment, dry granulation is preferred. Granulation by dry granulation can be carried out using, for example, a dry granulator RC-156 manufactured by Freund Corporation.

The granules thus produced are then compressed into tablets after adding external additives containing cellulose and/or a cellulose derivative and, optionally, one or more other ingredients. Any method can be used to add the external additives around the granules. The punch pressure per tablet can be, for example, an upper limit of 20 kN or less, or 18 kN or less, or 16 kN or less, and a lower limit of 2 kN or more, or 3 kN or more, or 4 kN or more. The punch shape can be a standard R, or, for example, a two-stage R, a sugar-coated R, a corner R, a corner flat, or a rounded flat.

Although various aspects of the present invention have been described above, the present invention is not limited to these aspects. As will be clear to those skilled in the art, any other aspect of the present invention may be extracted from the above detailed description and the description of the examples below.

The present invention will be described in more detail below with reference to examples. However, these examples are merely provided for the convenience of explanation, and the present invention is in no way limited to these examples.

[Prescription]
Tablets were manufactured according to the formulation shown in the table below.

Details of the raw materials used in the above examples and comparative examples are as follows.
Magnesium oxide: Kyowa Chemical Industry Co., Ltd., Japanese Pharmacopoeia Magnesium Oxide (heavy grade)
Crystalline cellulose: CEOLUS PH-101 (Examples 1-4, Comparative Examples 1-3), CEOLUS UF-711 (Examples 5-8, Comparative Examples 4-6), manufactured by Asahi Kasei Corporation
Croscarmellose sodium: Kiccolate ND-2HS manufactured by Nichirin Chemical Industry Co., Ltd.
Calcium stearate: Taihei Chemical Industry Co., Ltd. Calcium stearate (vegetable)

The physical properties of the magnesium oxide used in this example were measured and found to be as follows:
Average particle size: 7.691 μm (measured by laser diffraction scattering method using Microtrackbell Co., Ltd. MT3300 EX2)
Bulk density: 0.249 g/mL (measured using a 100 mL stainless steel cup (actual mass (g)/100 (mL)))
Angle of repose: 41.7° (measured using a multi-tester MT-1 manufactured by Seishin Enterprise Co., Ltd.)

[Manufacturing method]
According to the above recipe, each raw material was weighed on a 15,000 tablet scale using an electronic balance (Mettler Toledo, 5 kg capacity PB5001-S/FACT).
1. Mixing The weighed magnesium oxide and internal additive raw materials were placed in a polyethylene bag (1100 mm x 600 mm), and the bag was shaken left and right 30 times to mix. After the mixing process, the bulk density was measured using a 100 mL stainless steel cup (actual measured mass (g)/100 (mL)).
2. Granulation The resulting mixture was granulated using a dry granulator (Freund Corporation, Dry Granulator RC-156) under the following granulation conditions to produce granules.

After granulation, the following evaluation items were evaluated.
Flake ratio: The masses of a 1-minute processed product (A) obtained by carrying out a granulation process for 1 minute and a product (B) obtained by sieving the 1-minute processed product (A) through a 1000 μm sieve were measured, and the mass was calculated using the following formula 3.

Bulk density: Measured using a 100 mL stainless steel cup (actual measured mass (g)/100 (mL)) Particle size distribution: Measured using a particle size distribution analyzer (Laser diffraction/scattering particle size distribution analyzer LMS-2000e, manufactured by Seishin Enterprise Co., Ltd.) 3. Addition of external additives The above granules and the weighed raw materials of the external additives were placed in a polyethylene bag (1100 mm x 600 mm), and the bag was shaken left and right 30 times to mix.
After mixing, the following evaluation items were evaluated.
Bulk density: Measured using a 100 mL stainless steel cup (actual measured mass (g)/100 (mL)) Angle of repose: Measured using a Multitester MT-1 manufactured by Seishin Enterprise Co., Ltd. 4. Tableting The mixed granules and external additives were tableted using a tablet press (Kikusui Seisakusho Co., Ltd. small high-speed rotary tablet press VIRG) under the following conditions.

After tableting, the following evaluation items were evaluated.
Mass: (Number of tablets tested: 10 tablets)
・Thickness: (Number of tablets tested: 5 tablets), using a Peacock thickness gauge ・Hardness: (Number of tablets tested: 10 tablets), using an Okada Seiko Co., Ltd. load cell type benchtop hardness tester DC-50 ・Friability test: Using a Toyama Sangyo Co., Ltd. tablet friability tester TFT-1200, performed at 100 rotations (number of tablets tested: as close as possible to 6.5g) ・Disintegration time: (Number of tablets tested: 6 tablets), in accordance with the 17th edition of the Japanese Pharmacopoeia, general testing methods/disintegration testing methods. The disintegration time of the test tablets in water was measured using a disintegration tester (Toyama Sangyo Co., Ltd., Disintegration Tester NT-20HS). Tableting status: Tableting pressure/presence or absence of tableting problems was confirmed visually. Suspended particle diameter D50 (μm): (Number of test tablets: 1 tablet). The suspended particle diameter when the test tablet was suspended in water was measured using a laser diffraction/scattering particle size distribution analyzer LMS-2000e manufactured by Seishin Enterprise Co., Ltd. Tube passability 5 Fr: The plunger of a catheter syringe (Nipro Corporation, Enteral Nutrition Infusion Set Syringe DS 20 mL Catheter Yellow) was removed, one tablet was placed into the outer cylinder, the plunger was replaced, 20 mL of 55°C hot water was sucked up, the tip of the syringe was capped, and it was left to stand for 5 minutes. After 5 minutes, the catheter syringe was manually rotated 90 degrees back and forth 15 times, and then an enteral feeding tube (Atom Nutrition Catheter T, manufactured by Atom Medical; diameter 5 Fr, length 120 cm) was connected, and 20 mL of the suspension and ion-exchanged water for washing were further injected to check for tube occlusion. This test was performed three times, and the tube was evaluated as "pass" if it was not occluded and "fail" if it was occluded.
Calculation of compression rate in tableting process: Filling depth (a) and main compression thickness (b) are calculated using the following formula 4

[result]
The bulk density of the resulting mixture after mixing was measured and the results are shown in the table below.

The bulk density of the mixtures in both the Examples and Comparative Examples was within the range of 0.20 to 0.25 (g/mL), with no significant difference observed.
The measurement results for each item of the granules (granulated product) after granulation are shown in the table below.

With regard to granulation properties, the more crystalline cellulose contained as an internal additive, the better the processing ability and flake rate, and the higher the bulk density of the granulated product. This suggests that it is preferable to include a certain amount of crystalline cellulose as an internal additive.

The measurement results after adding external additives are shown in the table below.

When comparing the particle size after addition of external additives between Comparative Examples 1 and 4, which do not contain crystalline cellulose as an external additive, and Comparative Examples 3 and 6, which contain 100% crystalline cellulose as an external additive, an increase of 150 μm Pass was observed in Comparative Examples 3 and 6, but the angle of repose was in the range of 40° to 44°, so there was not much difference, and it is believed that there was no difference in flowability.

The measurement results for each item after tableting are shown in the table below.

As the mass ratio of crystalline cellulose contained as an external additive to that contained as an internal additive increased (Comparative Example 1 → Comparative Example 3, Comparative Example 4 → Comparative Example 6), hardness increased and friability decreased, but the incidence of capping increased and suspended particle aggregation was observed. As the mass ratio of crystalline cellulose contained as an external additive to that contained as an internal additive increased, the proportion of uncompressed crystalline cellulose that can contribute to tableting increased, and the compression rate during tableting increased, which is thought to have led to increased hardness and decreased friability. On the other hand, insufficient compaction during granulation made fine particles that did not completely form into flakes more likely to entrap air. Furthermore, the bulk density of the entire granules to be tableted decreased due to the influence of uncompressed crystalline cellulose added later, resulting in insufficient degassing during compression, resulting in an air-trapping state. This is thought to be the cause of the increased incidence of capping. Furthermore, in Comparative Example 3, in which all of the crystalline cellulose was contained as an external additive, clogging was observed during the tube passability test. Therefore, the mass ratio of crystalline cellulose contained as an external additive to reduce friability is preferably approximately 25 or more, and approximately 90 or less, when the mass of cellulose and/or cellulose derivatives contained in the entire tablet is taken as 100.

The tablet thickness after compression was in the range of 5.3 to 5.5 mm, with no significant difference observed. The disintegration time was within the appropriate range for both the Examples and Comparative Examples.

These results demonstrate that magnesium oxide tablets that achieve both reduced friability and reduced capping incidence can be efficiently produced by adjusting the mass ratio of [cellulose and/or cellulose derivatives contained as internal additives]:[cellulose and/or cellulose derivatives contained as external additives] to within the range of 75:25 to 10:90, for example, within the range of 75:25 to 20:80, and particularly within the range of 75:25 to 25:75. Furthermore, by achieving such a ratio, it is possible to achieve both reduced friability and reduced capping incidence while ensuring the physical properties required for tablet production, such as moldability, granulation ability, tableting ability, flowability, and tube passability, as well as the physical properties required for magnesium oxide tablets, such as disintegration ability.

The present invention has extremely high applicability in industrial fields where tablets with fewer defects in the identification information printed on their surfaces are required, particularly in the fields of pharmaceutical manufacturing and distribution.

10, 10A Manufacturing apparatus 12 Hopper 14 First conveying lane 16 Second conveying lane 18 Recovery section 20 Tablet 22 Discharge outlet 24 Conveying surface 26 Connecting pipe 28 First suction port 30 Conveying body 32 Second suction port 33 Air intake port 34 Suction pump 36 Receiving section 38 Conveying section 40 Vent 42 Printing conveying surface 44 Second conveying body 46 Second receiving section 48 Powder removal section 50 Printing section 52 Third suction port 54 Receiving section cover 58 Cover 60 Fourth suction port 62 Blowing port 64 Covering section 66 Guide section 68 Inclined surface 70 Direction gap 72 Upstream outer edge 74 Width outer edge 76 Width direction gap 78 Inspection camera 80 Printing head 82 Tablet recovery container 84 Container 86 Frame 88 Wheels 90 Discharge outlet 92 Butterfly valve 93 Support 94 Connecting body 96 Bucket lifter 98, tablet buffer chute 100, tower 102, bucket 104, lifting mechanism 106, receiving port portion 108, supply port portion 110, tablet press 112, internal space 114, receiving port 116, supply port 118, cylindrical portion 120, second blowing port 122, fifth suction port 124, sliding portion

Claims (5)

a conveying step of dropping the tablets manufactured in the pre-treatment step from a connecting pipe connected to a hopper into a receiving section below in a vertical direction on a conveying surface for conveying the tablets, and conveying the tablets from the receiving section downstream in the conveying direction;
A printing process is provided for printing on the surface of the tablet after the conveying process,
The conveying step includes a first suction step of suctioning powder separated from the surface of the dropped tablet by suctioning gas between the connecting pipe and the conveying surface,
The conveying step is inclined downward in the vertical direction toward the downstream of the conveying direction, and further includes a second suction step of sucking powder separated from the surface of the tablet by sucking gas above the conveying surface from below the conveying surface downstream of the receiving section in the conveying direction,
The second suction step uses a mesh or punched metal that sucks powder away from the surface of the tablet ,
The printing step includes a powder removal step of blowing gas onto a printing conveying surface that conveys the tablet in a direction opposite to the conveying direction and sucking up powder that has separated from the surface of the tablet before printing on the surface of the tablet,
The powder removal step includes a cover having a height gap shorter than the height length of the tablet, preventing the tablet from entering through the height gap and preventing the tablet from passing between the printing conveying surfaces that convey the tablet, and the gas blown out in the opposite direction to the conveying direction toward the printing conveying surface that conveys the tablet is sucked in the cover .
Tablet manufacturing method. The tablet manufacturing method described in claim 1, wherein the conveying process is performed using a vibrating feeder. The tablet manufacturing method described in claim 1, further comprising a third suction step in which the tablet is dropped from the conveying surface of the conveying step onto a printing conveying surface that conveys the tablet during the printing step, and powder that has separated from the surface of the tablet is sucked in before printing is performed on the surface of the tablet. The pretreatment step includes:
a mixing step of mixing magnesium oxide particles with an internal additive containing cellulose and/or a cellulose derivative to obtain a mixture;
a granulation step of granulating the mixture into granules;
a tableting step of tableting the granules;
The method for producing a tablet according to claim 1, comprising: In the tableting step, an external additive containing cellulose and/or a cellulose derivative is added in addition to the granules,
The method for producing a tablet according to claim 4 , wherein the cellulose and/or the cellulose derivative comprises crystalline cellulose having an average particle size of 50 μm or less.