Medicament feeding device

Abstract

A drug delivery device (10) is provided with: a main body section (14) having a hollow section (26) therein; a partition wall (16) that partitions the hollow part (26) into a first chamber (32) and a second chamber (34); a drug (12) housed in the first chamber (32); a discharge unit (18) that is connected to the first chamber (32) and discharges the drug (12); a pressure generating agent (22) which is housed in the second chamber (34) and which expands by coming into contact with water to push the partition wall (16) toward the first chamber (32); a semipermeable membrane (20) that is connected to the second chamber (34) and seals the pressure generating agent (22) in the second chamber (34); and a water tank (24) that supplies water to the semipermeable membrane (20).

Description

Technical Field

[0001] The present invention relates to a medicine delivery device for continuously and slowly releasing medicine. Background Art

[0002] As a drug delivery device for continuously delivering drugs, an osmotic pressure-driven drug delivery device has been proposed (e.g., Japanese Patent No. 4176832). This drug delivery device uses liquid components that pass through a semipermeable membrane to swell a water-swellable substance sealed in the semipermeable membrane, thereby gradually delivering the drug into the body. Summary of the invention

[0003] The drug delivery device described in Japanese Patent No. 4176832 is driven by water flowing in from a semipermeable membrane. Therefore, there is a problem that the drug delivery device cannot operate reliably in areas where there is little body fluid and water is difficult to flow into the semipermeable membrane. For example, in tissues such as the surface of the eye, the nasal cavity, the ear (middle ear or inner ear), the digestive tract, the endometrium, the inside of the bone, the inside of the tumor, the lung, the bronchus, or the subcutaneous fat, a sufficient amount of water cannot be supplied, and the drug delivery device is difficult to operate reliably.

[0004] Therefore, the conventional osmotic pressure driven drug administration device has a problem that the indwelling site is limited.

[0005] The object of the present invention is to solve the above-mentioned problems.

[0006] (1) The first method disclosed below is a drug administration device, which comprises: a main body having a hollow portion inside; a partition wall that divides the aforementioned hollow portion into a first chamber and a second chamber; a drug contained in the aforementioned first chamber; a spraying portion that is connected to the aforementioned first chamber and sprays the aforementioned drug; a pressure generating agent that is contained in the aforementioned second chamber and expands by contact with water to push the aforementioned partition wall toward the aforementioned first chamber; a semipermeable membrane that is connected to the aforementioned second chamber and seals the aforementioned pressure generating agent in the aforementioned second chamber; and a water tank that supplies water to the aforementioned semipermeable membrane.

[0007] The drug delivery device of item (1) can deliver drugs continuously for a long time not only in areas with body fluids but also in areas without body fluids or with very little body fluids by supplying water from the water tank. Therefore, the drug delivery device of item (1) can be placed in various areas.

[0008] (2) In the pharmaceutical administration device described in the above item (1), the water tank may be configured to cover a portion of the semipermeable membrane exposed from the main body and at least a portion of an outer peripheral surface of the main body.

[0009] The pharmaceutical administration device of the above item (2) can directly supply water required for operation from the water tank to the semipermeable membrane, so that piping connecting the water tank and the semipermeable membrane is not required, and the device structure is simplified.

[0010] (3) The pharmaceutical administration device described in the above item (2) may be configured such that the water tank is connected to the main body in an empty state without containing water in an initial state before use so as to cover the semipermeable membrane, and the water tank has an inlet for introducing water immediately before use.

[0011] The drug administration device described in the above item (3) has an empty water tank in the initial state, thereby preventing water from coming into contact with the semipermeable membrane before use, preventing the drug from being sprayed out during transportation and storage, and providing excellent storage properties.

[0012] (4) The drug administration device described in any one of items (1) to (3) above may be a device in which the main body and the water tank have a double-tube structure in which the water tank surrounds the outer peripheral surface of the main body, and one end of the main body provided with the ejection portion protrudes from the water tank.

[0013] The drug administration device described in the above item (4) can reduce the total length including the main body and the water tank by making the main body and the water tank a double-tube structure, thereby making it more compact and easier to place in a living body.

[0014] (5) In the drug administration device described in the above item (1), the water tank may have a partition wall capable of sealing water, and the partition wall may be broken when the water tank is used.

[0015] The drug administration device of the above item (5) can isolate the water in the water tank from the semipermeable membrane until just before use, thereby preventing administration during storage.

[0016] (6) In the pharmaceutical administration device described in the above item (5), the water tank may contain water in an initial state before use.

[0017] The drug administration device of the above item (6) contains water in advance in the water tank. The drug administration device does not require the operation of injecting water into the water tank immediately before use, and thus has excellent operability.

[0018] (7) The pharmaceutical administration device described in the above item (5) may be configured such that, in an initial state before use, the water tank does not contain water, and the water tank may have an inlet for introducing water immediately before use.

[0019] The drug administration device of the above item (7) can be filled with water into the water tank immediately before use, so there is no need to store water in the tank for a long time, and the storage property is excellent.

[0020] (8) The drug administration device described in any one of items (5) to (7) above may be such that the water tank is separated from the main body in an initial state before use, the main body having a retaining end for retaining the semipermeable membrane and a mounting portion for mounting the water tank on the retaining end.

[0021] The drug administration device of item (8) can store the water tank containing water in a separated state, thereby effectively preventing water from contacting the semipermeable membrane before use and effectively preventing malfunction during storage. Therefore, the drug administration device of item (8) also has excellent storage properties.

[0022] (9) In the pharmaceutical administration device according to the above item (8), the semipermeable membrane may include a pointed object protruding from the semipermeable membrane to rupture the partition wall.

[0023] The drug administration device of the above item (9) can perform the breaking operation of breaking the partition wall by the pointed object simultaneously with the operation of attaching the water tank to the main body, thereby simplifying the preparation operation before use.

[0024] (10) In the pharmaceutical administration device described in any one of the above items (1) to (9), the water tank may have a valve mechanism that prevents water leakage and allows the inflow of fluid to replenish consumed water.

[0025] The pharmaceutical administration device described in the above item (10) can stabilize the supply of water to the semipermeable membrane by preventing the water tank from entering a depressurized state due to the transfer of water to the second chamber (consumption of water).

[0026] (11) In the pharmaceutical administration device described in any one of the above items (1) to (10), the water tank may be formed of a soft material that collapses as the water is consumed.

[0027] The pharmaceutical administration device of the above-mentioned item (11) can stabilize the supply of water to the semipermeable membrane by preventing the water tank from entering a depressurized state due to the transfer of water to the second chamber (consumption of water).

[0028] (12) In the pharmaceutical administration device according to any one of the above items (1) to (11), the water tank may contain a gel capable of retaining water.

[0029] The drug administration device of the above-mentioned item (12) contains water in a gel state in the water tank, and thus can prevent water from leaking from the water tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a cross-sectional view of the pharmaceutical administration device according to the first embodiment in an initial state.

[0031] Figure 2A yes Figure 1An enlarged cross-sectional view of the discharge portion of the drug delivery device, Figure 2B It is along Figure 2A A cross-sectional view taken along line IIB-IIB.

[0032] Figure 3A is Figure 1 An explanatory diagram of a method of injecting water into an inlet of a water tank in a drug delivery device. Figure 3B yes Figure 1 A cross-sectional view of the drug delivery device immediately after use.

[0033] Figure 4A is an explanatory diagram of a pharmaceutical administration device according to a first modification of the first embodiment. Figure 4B It is a cross-sectional view of a pharmaceutical administration device according to Modification 2 of the first embodiment.

[0034] Figure 5 It is a cross-sectional view of a pharmaceutical administration device according to Modification 3 of the first embodiment.

[0035] Figure 6 It is a cross-sectional view of the pharmaceutical administration device according to the second embodiment in an initial state.

[0036] Fig. 7A is Figure 6 An explanatory diagram of the process of installing a water tank on the main body of the drug delivery device. Figure 7B yes Figure 6 An enlarged cross-sectional view of the vicinity of the mounting portion of the pharmaceutical administration device. DETAILED DESCRIPTION

[0037] (First embodiment)

[0038] Figure 1 The drug delivery device 10 of the present embodiment shown is used in a manner of being embedded in a living body or attached to the surface of a living body. The drug delivery device 10 can continuously deliver the liquid drug 12 contained therein for a long period of several weeks to several years. The drug delivery device 10 can reduce the burden on the patient by reducing the frequency of drug delivery associated with invasion.

[0039] The drug delivery device 10 includes a main body 14, a partition wall 16, a discharge portion 18, a semipermeable membrane 20, a drug 12, a pressure generating agent 22, and a water tank 24. The main body 14 is formed as a straight tube having a cylindrical shape. The main body 14 has an inner peripheral surface 14a extending in the axial direction with a constant inner diameter. The inner peripheral surface 14a is composed of a smooth curved surface. The main body 14 has a hollow portion 26 surrounded by the inner peripheral surface 14a. The hollow portion 26 extends from one end 14b of the main body 14 in the axial direction to the other end 14c, opens as a first opening portion 28 at one end 14b, and opens as a second opening portion 30 at the other end 14c.

[0040] The main body 14 is formed of a metal material such as stainless steel, titanium alloy, aluminum alloy, or various hard resin materials.

[0041] It should be noted that the main body 14 may not have a structure in which the partition wall 16 described later is operated as a piston. In this case, the main body 14 may have various shapes capable of accommodating the desired amounts of the medicine 12 and the pressure generating agent 22 .

[0042] The partition wall 16 is accommodated in the cavity 26. The partition wall 16 is formed of an elastic material such as rubber or an elastomer. The partition wall 16 of the present embodiment is configured as a piston. That is, the partition wall 16 can slide and move with the inner peripheral surface 14a along the axial direction while being in liquid-tight and air-tight contact with the inner peripheral surface 14a of the main body 14. The partition wall 16 liquid-tightly and air-tightly divides the cavity 26 into a first chamber 32 on the side of one end 14b and a second chamber 34 on the side of the other end 14c. The partition wall 16 moves toward the side of the one end 14b, thereby reducing the volume of the first chamber 32, so that the medicine 12 accommodated in the first chamber 32 is discharged from the first chamber 32.

[0043] It should be noted that the partition wall 16 is not limited to the piston. When the shape of the main body 14 is not suitable for the movement of the piston, the partition wall 16 may be composed of a soft and flexible film.

[0044] The ejection portion 18 is located at one end 14b of the main body 14 and blocks the first opening 28. The ejection portion 18 is a cylindrical member housed in the hollow portion 26. The ejection portion 18 has a plug 38 that abuts against the inner peripheral surface 14a of the main body 14. The plug 38 has a spiral ejection groove 38a on the outer periphery. The ejection groove 38a communicates with the outside and the first chamber 32. The ejection groove 38a forms a flow path for the medicine 12 to flow out between the plug 38 and the inner peripheral surface 14a. It should be noted that the ejection portion 18 is not limited to the above-mentioned example, and can also be a needle tube for puncturing biological tissue.

[0045] The drug 12 is stored in the first chamber 32. The drug 12 is stored in the first chamber 32 as a liquid (drug solution). The drug 12 is pushed out from the first chamber 32 as the partition wall 16 moves, and is administered into the living body through the discharge portion 18.

[0046] The semipermeable membrane 20 is located at the other end 14c of the main body 14, blocking the second opening 30. The semipermeable membrane 20 seals the second chamber 34. The semipermeable membrane 20 has a small diameter portion 20a inserted into the hollow portion 26 of the main body 14, and a large diameter portion 20b protruding from the other end 14c of the main body 14. The small diameter portion 20a is in close contact with the inner peripheral surface 14a of the main body 14. The large diameter portion 20b has a diameter substantially the same as the outer peripheral surface 14d of the main body 14. The large diameter portion 20b is exposed in the internal space 24a of the water tank 24. The semipermeable membrane 20 is formed of a semipermeable membrane material that allows water to pass through but prevents the pressure generating agent 22 from passing through. As the semipermeable membrane material, for example, plasticized cellulose, hydroxyethyl methacrylate, polyurethane, polyamide, polyether-polyamide copolymer, or thermoplastic copolyester can be cited.

[0047] The pressure generating agent 22 is sealed in the second chamber 34 as a powder (solid) or an aqueous solution. The pressure generating agent 22 uses a substance that expands in volume when in contact with water, thereby generating sufficient pressure inside the second chamber 34. Examples of the pressure generating agent 22 include salt (sodium chloride), potassium chloride, magnesium chloride, calcium chloride, and highly absorbent polymers. Considering safety in the event of leakage, the pressure generating agent 22 can be salt (sodium chloride). It should be noted that the pressure generating agent 22 can also use a substance that reacts with water to generate gas.

[0048] The pressure generating agent 22 dissolves in the water that flows into the second chamber 34 through the semipermeable membrane 20, thereby increasing the volume of the second chamber 34. When the pressure generating agent 22 is a substance that generates osmotic pressure, a pressure corresponding to the osmotic pressure difference between the osmotic pressure of the salt concentration in the body and the osmotic pressure of the solution in the second chamber 34 is generated in the second chamber 34. Thus, a pressure difference is generated between the second chamber 34 and the first chamber 32. This pressure difference generates a driving force that causes the partition wall 16 to displace toward the one end 14b side.

[0049] The water tank 24 has a cylindrical box body 40 and a cap 42 that are concentric with the axis of the main body 14. The box body 40 and the cap 42 surround the outer side of the main body 14. Therefore, the main body 14 and the water tank 24 form a double-layer tube structure. The water tank 24 has an internal space 24a for containing water between the main body 14. In the state of providing the product, that is, the initial state, water is not contained in the internal space 24a, and the internal space 24a is empty. As an example, the internal space 24a has a volume larger than the volume obtained by adding the volume of the first chamber 32 and the volume of the second chamber 34. It should be noted that the volume of the internal space 24a is not limited to the above example, as long as it can contain the amount of water required to release all or part of the medicine 12 in the first chamber 32.

[0050] The box body 40 and the cap 42 are detachably connected by a screw structure 43. The box body 40 is located on the other end 14c side of the main body 14, and the cap 42 is located on the one end 14b side of the main body 14. The box body 40 has an inlet 44 for introducing water. In the initial state, the inlet 44 is closed by the cap 42. When the box body 40 is removed from the cap 42, the inlet 44 is exposed.

[0051] The cap 42 has one end 42a located near the one end 14b of the main body 14. The one end 42a of the cap 42 is separated from the one end 14b of the main body 14, so that a portion near the one end 14b of the main body 14 is exposed to the outside of the water tank 24. That is, the one end 14b of the main body 14 provided with the spraying portion 18 protrudes from the outside of the water tank 24.

[0052] like Figure 2A and Figure 2B As shown, the cap 42 has a gasket 46 at one end 42a. The gasket 46 seals the gap between the one end 42a (holding end 24b) and the outer peripheral surface 14d of the body 14 in a liquid-tight and air-tight manner. The gasket 46 prevents water from leaking from the gap between the body 14 and the water tank 24.

[0053] In addition, if Figure 1 As shown, the water tank 24 also has a valve mechanism 48. The valve mechanism 48 is composed of a check valve that prevents water from leaking from the internal space 24a of the water tank 24 and allows fluid to flow into the internal space 24a from the outside of the water tank 24. When the water tank 24 becomes negative pressure, the valve mechanism 48 keeps the internal space 24a of the water tank 24 at normal pressure by allowing air or body fluid to flow in from the outside. It should be noted that the valve mechanism 48 can also be composed of a non-woven fabric sheet that allows air to pass through and prevents water from passing through. As such a non-woven fabric sheet, for example, Micropore (registered trademark) made by 3M Company can be used. In addition, the water tank 24 can also be formed by a soft material that collapses as the water is consumed. In this case, the valve mechanism 48 is not required.

[0054] The pharmaceutical administration device 10 of the present embodiment is configured as described above, and its operation and method of use will be described below.

[0055] like Figure 3A As shown, the cap 42 of the water tank 24 is separated from the box body 40 immediately before use of the pharmaceutical administration device 10. The box body 40 is removed from the main body 14 while the cap 42 is attached to the main body 14. The introduction port 44 is exposed in the box body 40.

[0056] Next, as shown in the figure, water is introduced into the tank body 40 through the introduction port 44. The introduction of water into the tank body 40 can be performed using a syringe or the like.

[0057] Next, if Figure 3B As shown, the cap 42 is attached to the box body 40. Water is sealed in the internal space 24a of the water tank 24 by the cap 42. With the above operation, the preparation operation of the drug administration device 10 is completed.

[0058] Then, the drug administration device 10 is placed in a predetermined position inside the living body or on the surface of the body. In the drug administration device 10, the water sealed in the water tank 24 contacts the semipermeable membrane 20 and is transferred to the second chamber 34 at a predetermined flow rate set according to the size of the semipermeable membrane 20. The water flowing into the second chamber 34 dissolves or reacts in the pressure generating agent 22. The pressure generating agent 22 generates pressure (osmotic pressure) in the second chamber 34 by expansion. The pressure generated in the second chamber 34 pushes the partition wall 16 toward the end 14b of the main body 14, so that the drug 12 in the first chamber 32 is ejected from the ejection portion 18.

[0059] The ejection speed of the drug 12 can be precisely controlled by the shape of the semipermeable membrane 20. In addition, since the drug administration device 10 of this embodiment stores water required for operation in the water tank 24, the drug 12 can be continuously released to various parts of the body without body fluids.

[0060] (Variation 1 of the first embodiment)

[0061] like Figure 4A As shown, the pharmaceutical injection device 10A of this modification example includes a water transport mechanism 50 in the main body 14. It should be noted that the pharmaceutical injection device 10A of this modification example has the same structure as that of the pharmaceutical injection device 10A except for the water transport mechanism 50. Figure 1 to Figure 3B The same is true for the described pharmaceutical administration device 10. Therefore, in this modification, detailed description of the configuration other than the water transport mechanism 50 is omitted.

[0062] The water transport mechanism 50 is formed on the outer peripheral surface 14d of the main body 14. The water transport mechanism 50 has a groove 52 formed in a range that does not overlap with the liner 46 of the water tank 24. The groove 52 is formed in a spiral shape, and its end is connected to the semipermeable membrane 20. It should be noted that the shape of the groove 52 is not limited to the spiral shape, and it can also be a mesh shape or a linear shape. The groove 52 constituting the water transport mechanism 50 has a width and depth that allows the surface tension of water to work, and guides the water inside the water tank 24 to the semipermeable membrane 20 through capillary action.

[0063] The capillary force (surface tension) increases as the width of the groove 52 becomes narrower. On the other hand, if the width of the groove 52 becomes too narrow, the amount of water transported decreases. Therefore, the width and depth of the groove 52 are appropriately set according to the delivery speed of the medicine 12. The width and depth of the groove 52 can be, for example, 0.01 to 0.1 mm. In the example shown in the figure, the cross-section of the groove 52 has a V-shape. It should be noted that the cross-sectional shape of the groove 52 is not limited to the example shown in the figure, and can also be a rectangular shape or a U-shape. In addition, the surface of the groove 52 can also be covered with a hydrophilic coating. The hydrophilic coating increases the capillary force of the groove 52 and can more effectively guide water to the semipermeable membrane 20.

[0064] The pharmaceutical administration device 10A of the present modification example can guide water to the semipermeable membrane 20 even when the water in the water tank 24 is consumed and the water level is low, and thus can perform a more stable administration operation.

[0065] (Variation 2 of the first embodiment)

[0066] like Figure 4B As shown in FIG. 1 , the pharmaceutical injection device 10B of this modified example includes a water transport mechanism 50B in the main body 14. It should be noted that the pharmaceutical injection device 10B of this modified example has the same structure as that of the pharmaceutical injection device 10B except for the water transport mechanism 50B. Figure 1 to Figure 3B The same is true for the described pharmaceutical administration device 10. Therefore, in this modification, detailed description of the configuration other than the water transport mechanism 50B is omitted.

[0067] like Figure 4B As shown, the water transport mechanism 50B has a semipermeable membrane member 54. The semipermeable membrane member 54 is formed of the same material as the semipermeable membrane 20. The semipermeable membrane member 54 and the semipermeable membrane 20 may also be formed by being connected integrally. The semipermeable membrane member 54 extends from the other end 14c of the main body 14 toward the vicinity of the one end 42a of the cap 42 of the water tank 24. However, in order to prevent water leakage, the semipermeable membrane member 54 is arranged on the inner side of the water tank 24 more than the gasket 46. The semipermeable membrane member 54 is joined to the outer peripheral surface 14d of the main body 14 by a joining means such as an adhesive.

[0068] The semipermeable membrane member 54 can introduce water from a location away from the semipermeable membrane 20 to the semipermeable membrane 20 by increasing the surface area of ​​the semipermeable membrane material including the semipermeable membrane 20. Therefore, the pharmaceutical administration device 10B of this embodiment can introduce water to the semipermeable membrane 20 even when the water in the water tank 24 is consumed and the water becomes less, so a more stable administration operation can be performed.

[0069] (Variation 3 of the first embodiment)

[0070] like Figure 5As shown, in the pharmaceutical injection device 10C of this modified example, the water tank 24C does not have the cap 42, and is composed only of the tank body 40C. It should be noted that in the pharmaceutical injection device 10C of this modified example, the structure other than the water tank 24C (tank body 40C) is the same as that of the reference Figure 1 to Figure 3B The same is true for the described pharmaceutical administration device 10. Therefore, in this modification, detailed description of the components other than the water tank 24C (tank body 40C) will be omitted.

[0071] The box body 40C is formed in a cylindrical shape that is integrally formed as a whole. The box body 40C has an opening 56 at one end 40a through which the main body 14 passes. The opening 56 is sealed liquid-tightly and air-tightly. In addition, a valve mechanism 48 is provided at one end 40a of the box body 40C.

[0072] The other end 40b of the box body 40C covers the outside of the other end 14c of the main body 14. The box body 40C has a water filling port 60 at the other end 40b. The water filling port 60 is formed of an elastic material such as rubber through which a needle tube can pass. The water filling port 60 can be pierced by a needle tube of a syringe. The water tank 24C is used to fill water into the inside of the box body 40C through the water filling port 60.

[0073] The pharmaceutical injection device 10C of the present embodiment as described above does not require the operation of attaching or detaching the cap 42 , and thus the preparation work before use can be simplified.

[0074] (Second embodiment)

[0075] like Figure 6 As shown, the drug administration device 10D of this embodiment has a water tank 24D which is blocked by the partition wall 62 in the initial state. Figure 1 to Figure 3B The same components of the pharmaceutical injection device 10 described above are denoted by the same reference numerals, and detailed description thereof will be omitted.

[0076] The water tank 24D includes a box body 40D, a valve mechanism 48, and a partition wall 62. The box body 40D is cylindrical. An internal space 24a for accommodating water is formed inside the box body 40D. The box body 40D has an outer diameter larger than that of the main body 14, and one end 41a of the box body 40D has a threaded structure 64 for fixing to the main body 14. The threaded structure 64 is connected to a mounting portion 65 formed on the outer peripheral surface 14d near the other end 14c of the main body 14 by threaded fastening.

[0077] The water tank 24D contains water in the internal space 24a closed by the partition wall 62 in the initial state. The water tank 24D can provide products in a state of containing water. It should be noted that the water tank 24D may not contain water in the internal space 24a in the initial state. In this case, the water tank 24D may also be provided with an introduction port for introducing water into the water tank 24D just before use.

[0078] The valve mechanism 48 is located at the other end 41b of the box body 40D and blocks the internal space 24a. The valve mechanism 48 may be a check valve that prevents water from flowing out and allows fluid to flow in from the outside. The valve mechanism 48 may also be a nonwoven fabric sheet that prevents water from passing through.

[0079] The partition wall 62 is located at one end 41a of the tank body 40D and closes the internal space 24a of the tank body 40D in a liquid-tight and air-tight manner. The partition wall 62 is breakable and breaks when the water tank 24D is mounted on the main body 14. Such a partition wall 62 can be made of a rubber material having a cutout, for example.

[0080] On the other hand, the main body 14 of this embodiment has a mounting portion 65 on the outer peripheral surface 14d near the other end 14c. The screw structure 64 of the water tank 24D is mounted on the mounting portion 65. The mounting portion 65 and the screw structure 64 seal the internal space 24a of the water tank 24 in a liquid-tight manner.

[0081] The semipermeable membrane 20 of this embodiment has a pointed object 66 protruding outward. Figure 6 As shown, when the water tank 24D is mounted on the main body 14 , the spike 66 breaks the partition wall 62 , so that the internal space 24 a of the water tank 24D communicates with the semipermeable membrane 20 .

[0082] The pharmaceutical administration device 10D of this embodiment is configured as described above. Figure 6 As shown, in the initial state of the pharmaceutical administration device 10D provided as a product, the water tank 24D is separated from the main body 14 .

[0083] like Fig. 7A As shown in FIG. 1 , the water tank 24D is installed on the main body 14 immediately before use. When the water tank 24D is installed on the main body 14, the pointed object 66 breaks the partition wall 62 of the water tank 24D. As a result, as shown in FIG. Figure 7B As shown, the inner space 24a of the water tank 24D communicates with the semipermeable membrane 20, and the water inside contacts the semipermeable membrane 20. Then, the water tank 24D and the main body 14 are connected to each other by the screw structure 64 and the mounting portion 65 in a liquid-tight manner.

[0084] As described above, the pharmaceutical administration device 10D of this embodiment can supply water required for operation from the water tank 24D, so the administration operation can be performed even if it is placed in a place without body fluids.

[0085] In addition, the pharmaceutical injection device 10D of the present embodiment does not require preparation work involving syringe work, such as introducing water into the water tank 24D before starting use.

[0086] It should be noted that the present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. For example, the water tanks 24, 24C, and 24D may include a gel capable of retaining water.

Claims

1. A drug delivery device, comprising: a main body portion having a hollow portion therein; a partition wall which divides the cavity into a first chamber and a second chamber; A medicine contained in the first chamber; a discharge portion connected to the first chamber and configured to discharge the medicine; a pressure generating agent contained in the second chamber and expanding upon contact with water to push the partition wall toward the first chamber; a semipermeable membrane connected to the second chamber to seal the pressure generating agent in the second chamber; and A water tank supplies water to the semipermeable membrane.

2. The drug delivery device according to claim 1, wherein: The water tank is configured to cover a portion of the semipermeable membrane that is exposed from the main body and at least a portion of an outer peripheral surface of the main body.

3. The drug delivery device according to claim 2, wherein: The water tank is connected to the main body in an empty state without containing water in an initial state before use so as to cover the semipermeable membrane, and the water tank has an inlet for introducing water immediately before use.

4. The drug delivery device according to claim 2, wherein: The main body and the water tank have a double-tube structure in which the water tank surrounds the outer peripheral surface of the main body, and one end of the main body provided with the spout protrudes from the water tank.

5. The drug delivery device according to claim 1, wherein: The water tank has a partition wall capable of sealing water, and the partition wall can be broken when the water tank is used.

6. The drug delivery device according to claim 5, wherein: The water tank contains water in an initial state before use.

7. The drug delivery device according to claim 5, wherein: In the initial state before use, the water tank does not contain water. The water tank has an inlet for introducing water immediately before use.

8. The drug delivery device according to claim 5, wherein: The water tank is separated from the main body in an initial state before use, and the main body has a holding end portion for holding the semipermeable membrane and a mounting portion for mounting the water tank on the holding end portion.

9. The drug delivery device according to claim 8, wherein: The semipermeable membrane has a pointed object protruding from the semipermeable membrane to break the partition wall.

10. The pharmaceutical administration device according to any one of claims 1 to 9, wherein The water tank has a valve mechanism that prevents water leakage and allows the inflow of fluid for replenishing the consumed water.

11. The pharmaceutical administration device according to any one of claims 1 to 9, wherein The water tank is formed of a soft material that collapses as the water is consumed.

12. The pharmaceutical administration device according to any one of claims 1 to 9, wherein The water tank contains a gel capable of retaining water.

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