Drug administration device
The drug administration device addresses the reliability issue in low-fluid areas by using a water transport mechanism with capillary action to ensure continuous drug release, expanding its applicability to various body sites.
Patent Information
- Application Number
- JP2022162014
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2022-10-07
- Publication Date
- 2025-12-05
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
Conventional osmotic pressure-driven drug administration devices struggle to operate reliably in areas with low bodily fluid, limiting their implantation sites to specific locations such as the surface of the eye, nasal cavity, ear, digestive tract, endometrium, inside of bones, inside of tumors, lungs, and subcutaneous fat.
A drug administration device with a water transport mechanism that utilizes capillary action through fine flow paths, including grooves or fibers, to draw water to the semipermeable membrane, ensuring continuous drug release even in areas with little body fluid, and includes a semipermeable membrane member to enhance water intake.
Enables stable and continuous drug administration over an extended period, even in regions with low bodily fluid, by efficiently drawing water to the semipermeable membrane, thus expanding the device's implantation sites and reducing the frequency of invasive drug administration.
Smart Images
Figure 2025176720000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a drug delivery device for continuous, sustained release of a drug. [Background technology]
[0002] An osmotic pressure-driven drug administration device has been proposed as a drug administration device for continuously administering a drug (for example, Patent Document 1). In this drug administration device, a water-swellable substance sealed by a semipermeable membrane swells due to a liquid component that has permeated the semipermeable membrane, gradually administering the drug into the living body. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Patent No. 4176832 Summary of the Invention [Problem to be solved by the invention]
[0004] The drug administration device described in Patent Document 1 is driven by the inflow of water through a semipermeable membrane. Therefore, there is a problem that it does not operate reliably in places where there is little bodily fluid and it is difficult for water 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 bones, the inside of tumors, the lungs, the bronchi, or subcutaneous fat, a sufficient amount of water is not supplied, making it difficult for the drug administration device to operate reliably.
[0005] Therefore, conventional osmotic pressure-driven drug administration devices have the problem that the implantation site is limited.
[0006] An object of the present invention is to solve the above-mentioned problems. [Means for solving the problem]
[0007] (1) A first aspect of the disclosure below is a drug administration device comprising: a main body having a hollow portion therein; a partition wall dividing the hollow portion into a first chamber and a second chamber; a drug contained in the first chamber; an ejection portion provided in the first chamber and ejecting the drug; 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 provided in the second chamber and sealing the pressure-generating agent in the second chamber; and a water transport mechanism that guides water from a location away from the semipermeable membrane to the semipermeable membrane.
[0008] The drug administration device of the above item (1) can draw water into the semipermeable membrane by using a water transport mechanism, and therefore can continuously and gradually release the drug even in areas with little body fluid.
[0009] (2) In the drug administration device described in the above item (1), the water transport mechanism may have a fine flow path that utilizes capillary action to guide water to the semipermeable membrane.
[0010] The drug administration device of item (2) above can draw water into the semipermeable membrane through a fine flow path formed by a cylinder, a groove, gaps between fibers, etc., enabling stable administration operation.
[0011] (3) In the drug administration device according to the above item (2), the microchannel may be covered with a film made of a hydrophilic material.
[0012] The drug administration device of the above item (3) can increase the surface tension between the fine flow channel and water, and can more effectively guide water to the semipermeable membrane.
[0013] (4) In the drug administration device according to the above item (2) or (3), the fine flow channel may include a fine groove formed on the outer circumferential surface of the main body portion.
[0014] The drug administration device of the above item (4) allows for a miniaturized water transport mechanism. In addition, this drug administration device is easy to process, so the product can be provided at low cost.
[0015] (5) In the drug administration device described in item (4) above, the main body portion has a membrane holding portion that holds the semipermeable membrane, the membrane holding portion has an opening into which the semipermeable membrane is inserted and an end face that surrounds the opening, the semipermeable membrane has a small diameter portion inserted into the opening and a large diameter portion that is larger in diameter than the small diameter portion, the large diameter portion abuts against the end face of the main body portion, and one end of the fine groove may open at the end face of the main body portion.
[0016] In the drug administration device described in the above item (5), the ends of the fine grooves are connected to the large diameter portion of the semipermeable membrane, so that water can be efficiently drawn into the semipermeable membrane.
[0017] (6) In the drug administration device described in item (5) above, the main body portion has a long, cylindrical shape, the ejection portion is formed at one end of the main body portion in the long direction, the semipermeable membrane is formed at the other end of the main body portion in the long direction, and the fine grooves may extend from the other end of the outer peripheral surface to the one end.
[0018] The drug administration device of the above item (6) can draw water into the semipermeable membrane if any part of the main body between one end and the other end can come into contact with water such as body fluids.
[0019] (7) In the drug administration device according to any one of the above items (1) to (6), the water transport mechanism may include a semipermeable membrane member extending from the semipermeable membrane.
[0020] The medicine administration device of the above item (7) can draw in water through the semipermeable membrane member, thereby enabling a more stable administration operation.
[0021] (8) In the drug administration device described in the above item (7), the semipermeable membrane member may extend along the main body portion.
[0022] The drug administration device described in item (8) above can draw water required for operation into the semipermeable membrane by bringing any part of the semipermeable membrane member into contact with a portion rich in water (body fluid).
[0023] (9) In the drug administration device according to the above item (8), the semipermeable membrane member may be fixed to the main body portion.
[0024] The drug administration device described in item (9) above can draw water required for operation into the semipermeable membrane if any part of the main body is in contact with a part rich in water (body fluid).
[0025] (10) In the drug administration device according to any one of items (1) to (9), the semipermeable membrane may be made of any one of plasticized cellulose, hydroxyethyl methacrylate, polyurethane, polyamide, polyether-polyamide copolymer, and thermoplastic copolyester.
[0026] The drug administration device of the above item (10) allows for a more stable administration operation by drawing water into the semipermeable membrane through the hydrophilic material. [Brief explanation of the drawings]
[0027] [Figure 1] FIG. 1A is a cross-sectional view of a medicine injection device according to a first embodiment, and FIG. 1B is a plan view of the outer periphery of the medicine injection device of FIG. 1A. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1B. [Figure 3] FIG. 3A is a plan view of a medicine injection device according to a second embodiment, and FIG. 3B is a plan view of a medicine injection device according to a third embodiment. [Figure 4] FIG. 4A is a plan view of a drug injection device according to a fourth embodiment, and FIG. 4B is a cross-sectional view of a drug injection device according to a fifth embodiment. [Figure 5] FIG. 5 is a perspective view of a medicine injection device according to a sixth embodiment. [Figure 6] FIG. 6 is a cross-sectional view of the drug administration device of FIG. [Figure 7] FIG. 7 is an explanatory diagram of the operation of the medicine injection device of FIG. [Figure 8] FIG. 8 is a perspective view of a medicine injection device according to the seventh embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0028] (First embodiment) A drug administration device 10 according to this embodiment shown in Figure 1A is used by being wholly or partially implanted inside a living body. This drug administration device 10 can continuously administer a liquid drug 12 contained therein for a relatively long period of time, such as several weeks to several years. By reducing the frequency of frequent invasive drug administration, drug administration device 10 can reduce the burden on the patient.
[0029] The drug administration device 10 is an osmotic pressure-driven device. The drug administration device 10 includes a main body 14, a partition wall 16, an ejection section 18, a semipermeable membrane 20, a drug 12, a pressure-generating agent 22, and a water transport mechanism 24 (see FIG. 1B). The main body 14 is formed as a straight tube having a cylindrical shape. The main body 14 has an inner circumferential surface 14a extending axially with a constant inner diameter. The inner circumferential surface 14a is configured as a smoothly curved surface. The main body 14 has a cavity 26 surrounded by the inner circumferential surface 14a. The cavity 26 extends from one end 14b to the other end 14c in the axial direction of the main body 14, opening at the one end 14b as a first opening 28 and at the other end 14c as a second opening 30. The other end 14c of the main body 14 has an end face 31 surrounding the second opening 30.
[0030] The main body 14 is formed from a metal material such as stainless steel, titanium alloy, or aluminum alloy, or from various hard resin materials.
[0031] The main body 14 may have a structure in which the partition wall 16, which will be described later, does not function as a piston. In this case, the main body 14 may have various shapes capable of accommodating a desired amount of the drug 12 and pressure-generating agent 22.
[0032] The partition wall 16 is housed in the cavity 26. The partition wall 16 is made of an elastic material such as rubber or elastomer. In this embodiment, the partition wall 16 is configured as a piston. That is, the partition wall 16 is in liquid-tight and airtight contact with the inner circumferential surface 14a of the main body 14 and can move axially while sliding against the inner circumferential surface 14a. The partition wall 16 liquid-tightly and airtightly divides the cavity 26 into a first chamber 32 on one end 14b side and a second chamber 34 on the other end 14c side. By moving toward the one end 14b side, the partition wall 16 reduces the volume of the first chamber 32, thereby expelling the drug 12 housed in the first chamber 32 from the first chamber 32.
[0033] The partition wall 16 is not limited to a piston. If the shape of the main body 14 is not suitable for the movement of a piston, the partition wall 16 may be made of a soft and flexible film.
[0034] The ejection part 18 is located at one end 14b of the main body part 14 and closes the first opening 28. The ejection part 18 is a cylindrical member housed in the hollow part 26. The ejection part 18 has a plug 38 that abuts against the inner circumferential surface 14a of the main body part 14. The plug 38 has a spiral ejection groove 38a on its outer periphery. The ejection groove 38a connects the outside with the first chamber 32. The ejection groove 38a forms a flow path between the plug 38 and the inner circumferential surface 14a for discharging the drug 12. Note that the ejection part 18 is not limited to the above example, and may be a needle tube 50 (see FIG. 6) or a tube.
[0035] The drug 12 is contained in the first chamber 32. The drug 12 is contained in the first chamber 32 as a liquid (medicinal liquid). The drug 12 is pushed out of the first chamber 32 as the partition wall 16 moves, and is administered into the living body through the discharge portion 18.
[0036] The semipermeable membrane 20 is located at the other end 14c of the main body 14 and blocks the second opening 30. The other end 14c is a membrane holding portion that holds the semipermeable membrane 20. The semipermeable membrane 20 seals the second chamber 34. The semipermeable membrane 20 has a small-diameter portion 20a that is inserted into the cavity 26 (second opening 30) of the main body 14 and a large-diameter portion 20b that protrudes from the other end 14c of the main body 14. The small-diameter portion 20a is in close contact with the inner circumferential surface 14a of the main body 14. The large-diameter portion 20b has approximately the same diameter as the outer circumferential surface 14d of the main body 14. As shown in FIG. 1B, the large-diameter portion 20b connects to a groove 40 that constitutes the water transport mechanism 24. The semipermeable membrane 20 is formed of a semipermeable membrane member that allows water to pass through while blocking the pressure-generating agent 22. Semipermeable membrane members include, for example, those made of plasticized cellulose, hydroxyethyl methacrylate, polyurethane, polyamide, polyether-polyamide copolymer, or thermoplastic copolyester.
[0037] 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 is a substance that expands in volume upon contact with water and generates sufficient pressure inside the second chamber 34. Examples of the pressure-generating agent 22 include various substances that generate osmotic pressure. Examples of pressure-generating agents 22 that generate osmotic pressure include table salt (sodium chloride), potassium chloride, magnesium chloride, calcium chloride, and highly water-absorbent polymers. In consideration of safety in the event of leakage, table salt (sodium chloride) may be used as the pressure-generating agent 22. Note that the pressure-generating agent 22 may also be a substance that reacts with water to generate gas.
[0038] The pressure-generating agent 22 increases the pressure and volume of the second chamber 34 by coming into contact with water that has permeated the semipermeable membrane 20 and flowed into the second chamber 34. The pressure-generating agent 22 generates pressure in the second chamber 34 that corresponds to, for example, the difference between the salt concentration in the body and the osmotic pressure in the second chamber 34. As a result, a pressure difference occurs between the second chamber 34 and the first chamber 32, and this pressure difference generates a driving force that displaces the partition wall 16 toward the one end 14b.
[0039] As shown in Fig. 1B, the water transport mechanism 24 of this embodiment is formed on the outer peripheral surface 14d of the main body 14. The water transport mechanism 24 has a groove 40 extending from one end 14b of the main body 14 to the other end 14c. As shown in Fig. 2, the groove 40 is formed by carving the outer peripheral surface 14d of the main body 14. Such a groove 40 can be formed, for example, by a laser processing method in which a laser beam is irradiated onto the outer peripheral surface 14d of the main body 14.
[0040] The grooves 40 are microgrooves having a width and depth that allow surface tension to act and guide bodily fluids to the semipermeable membrane 20 by capillary action. While the capillary force (surface tension) increases as the width of the grooves 40 narrows, the amount of water transport decreases if the width of the grooves 40 becomes too narrow. Therefore, the width and depth of the grooves 40 are appropriately set according to the administration speed of the drug 12. The width and depth of the grooves 40 may be, for example, 0.01 to 0.1 mm. In the illustrated example, the grooves 40 have a V-shaped cross section. The cross-sectional shape of the grooves 40 is not limited to the illustrated example and may be rectangular or U-shaped. In this embodiment, the number of grooves 40 constituting the water transport mechanism 24 is not limited to one, and multiple grooves 40 may be used. The water transport mechanism 24 may also have multiple grooves 40 intersecting in a mesh pattern.
[0041] 2, the groove portion 40 may have a hydrophilic coating layer 42. The hydrophilic coating layer 42 is formed so as to cover at least the inner surface of the groove portion 40. Examples of materials for the hydrophilic coating layer 42 include phosphobetaine polymer, sulfobetaine polymer, and carboxybetaine polymer. Note that if the main body portion 14 is formed of a highly hydrophilic material, the hydrophilic coating layer 42 may not be formed on the groove portion 40.
[0042] The medicine injection device 10 of this embodiment is configured as described above, and its operation will be described below.
[0043] The drug administration device 10 is placed so as to straddle a region with a relatively small amount of bodily fluid and a region where a supply of bodily fluid is expected. As a result, even when the semipermeable membrane 20 of the drug administration device 10 is placed in a region with a small amount of bodily fluid, at least a portion of the groove 40 constituting the water transport mechanism 24 comes into contact with the bodily fluid. The bodily fluid that comes into contact with the groove 40 spreads over the entire area of the groove 40 due to surface tension. As a result, the bodily fluid containing water is guided to the semipermeable membrane 20 through the groove 40. The water from the bodily fluid that comes into contact with the semipermeable membrane 20 passes through the semipermeable membrane 20 and flows into the second chamber 34, where it comes into contact with the pressure-generating agent 22 (table salt) in the second chamber 34. As a result, a portion of the pressure-generating agent 22 dissolves in water and expands, increasing the pressure inside the second chamber 34. As the pressure in second chamber 34 increases, partition wall 16 moves toward one end 14b and presses first chamber 32, causing drug 12 contained in first chamber 32 to be released into the living body through discharge port 18. Water is slowly supplied to second chamber 34 through semipermeable membrane 20, so drug administration device 10 can administer drug 12 continuously for a long period of time.
[0044] As described above, even when semipermeable membrane 20 is placed in a region with a relatively low water content (body fluid), drug administration device 10 of this embodiment can administer drug 12 by drawing water into semipermeable membrane 20 through water transport mechanism 24. Therefore, drug administration device 10 of this embodiment can be implanted in a wide range of regions, and can administer drug 12 to tissues with low water content.
[0045] (Second embodiment) Figure 3A shows a pharmaceutical injection device 10A of this embodiment. In the configuration of this embodiment and pharmaceutical injection devices 10B to 10F described below, the same components as those of pharmaceutical injection device 10 described with reference to Figures 1A to 2 are designated by the same reference numerals, and detailed description thereof will be omitted.
[0046] The medicine administration device 10A has a water transport mechanism 24A on the outer peripheral surface 14d of the main body 14. In this embodiment, the water transport mechanism 24A has a groove 40A formed on the outer peripheral surface 14d of the main body 14. The groove 40A is formed as a fine groove having a rectangular, V-shaped, or U-shaped cross section. The groove 40A extends from one end 14b to the other end 14c of the main body 14, spirally circumferentially around the outer peripheral surface 14d of the main body 14. The groove 40A is connected to the semipermeable membrane 20.
[0047] In this embodiment, the groove 40A is formed in a spiral shape, and therefore can come into contact with bodily fluids in various directions in the circumferential direction of the main body 14. Therefore, the groove 40A can draw water into the semipermeable membrane 20 from areas rich in bodily fluids throughout the entire circumferential direction of the main body 14, enabling more reliable operation of the drug administration device 10A. Note that in this embodiment, the number of grooves 40A constituting the water transport mechanism 24A does not need to be limited to one, and the water transport mechanism 24A may be composed of multiple grooves 40A. Furthermore, the water transport mechanism 24A may have multiple grooves 40A that intersect in a mesh pattern.
[0048] (Third embodiment) As shown in FIG. 3B, drug administration device 10B of this embodiment has, as water transport mechanism 24B, tube 44 connected to semipermeable membrane 20. Tube 44 has a fine flow path therein. One end of tube 44 is connected to semipermeable membrane 20, and the free end of tube 44 extends to a location away from semipermeable membrane 20. The internal flow path of tube 44 opens at the free end. Water transport mechanism 24B can take in water, such as body fluids, from the free end of tube 44 into the flow path. The water taken in tube 44 is guided to semipermeable membrane 20 by capillary force and is used to drive partition wall 16. Drug administration device 10B of this embodiment can draw water, such as body fluids, into semipermeable membrane 20 from a location away from main body 14.
[0049] (Fourth embodiment) As shown in Figure 4A, medicine administration device 10C of this embodiment has, as water transport mechanism 24C, fabric 46 connected to semipermeable membrane 20. Fabric 46 is made of hydrophilic fibers, and capillary force acts in the fine gaps between the fibers. Therefore, fabric 46 can draw water into semipermeable membrane 20 through the gaps in the fibers.
[0050] (Fifth embodiment) As shown in FIG. 4B, the drug administration device 10D of this embodiment has a semipermeable membrane member 48 as a water transport mechanism 24D. The semipermeable membrane member 48 is made of the same material as the semipermeable membrane 20. The semipermeable membrane member 48 and the semipermeable membrane 20 may be formed as an integral unit. The semipermeable membrane member 48 extends from the other end 14c to the one end 14b of the main body 14. The semipermeable membrane member 48 is joined to the outer peripheral surface 14d of the main body 14 by a joining means such as an adhesive.
[0051] The semipermeable membrane member 48 can increase the contact area with a site wetted with body fluid by increasing the surface area of the semipermeable membrane material including the semipermeable membrane 20. The semipermeable membrane member 48 can also draw water into the semipermeable membrane 20 from a site distant from the semipermeable membrane 20. Therefore, the drug administration device 10D of this embodiment can be driven even in a site with little body fluid.
[0052] (Sixth embodiment) This embodiment shows an osmotic pressure-driven drug administration device 10E that is placed on the ocular surface 80 (see FIG. 7). As shown in FIGS. 5 and 6, drug administration device 10E of this embodiment has a main body 14 that is annular. As shown in FIG. 7, drug administration device 10E is placed so as to surround the periphery of cornea 82, and is used with needle tube 50 connected to discharge portion 18 inserted into eyeball 84.
[0053] As shown in Figure 6, the main body 14 has one end 14b and the other end 14c connected to each other to form a ring. The discharge section 18 attached to one end 14b of the main body 14 has a needle tube 50. The needle tube 50 is located near the semipermeable membrane 20 attached to the other end 14c of the main body 14. A partition wall 16 is arranged in the hollow section 26 inside the main body 14. The partition wall 16 liquid-tightly and air-tightly separates the hollow section 26 into a first chamber 32 communicating with the needle tube 50 and a second chamber 34 on the semipermeable membrane 20 side. The first chamber 32 contains a liquid drug 12, and the second chamber 34 contains a pressure-generating agent 22.
[0054] As shown in Figure 7, drug administration device 10E of this embodiment is placed in the pocket-like space between eyeball 84 and eyelid so as to surround cornea 82. When body fluid such as tear fluid 86 comes into contact with semipermeable membrane 20, water flows into second chamber 34 through semipermeable membrane 20. As a result, pressure-generating agent 22 expands and operates to push partition wall 16 toward first chamber 32.
[0055] In order for drug administration device 10E of this embodiment to stably administer drug 12, a sufficient amount of tear fluid 86 must be supplied to semipermeable membrane 20. On ocular surface 80, tear fluid 86 secreted from lacrimal gland 88 accumulates in tear meniscus 92 located along lower eyelid 90 of the eye. Therefore, from the viewpoint of stable operation of drug administration device 10E, it is preferable to place semipermeable membrane 20 on tear meniscus 92.
[0056] However, when semipermeable membrane 20 of drug administration device 10E is positioned at tear meniscus 92, needle tube 50 is also placed near tear meniscus 92. In this case, the puncture site of needle tube 50 is located near tear meniscus 92. Leaving needle tube 50 near tear meniscus 92 for a long period of time increases the risk of infection due to bacterial contamination inside eyeball 84.
[0057] 7, it is preferable that the placement site of semipermeable membrane 20 and the puncture site of needle tube 50 be located away from tear meniscus 92 near upper eyelid 94. However, such a site away from tear meniscus 92 has little tear fluid 86 on ocular surface 80. Therefore, if semipermeable membrane 20 and needle tube 50 are placed in a position that reduces the risk of infection, there is a problem in that it becomes difficult to operate drug administration device 10E.
[0058] Therefore, as shown in Figure 5, the medicine administration device 10E of this embodiment has a water transport mechanism 24E on the outer peripheral surface 14d of the main body 14. The water transport mechanism 24E has a groove 40B that extends annularly along the axial direction of the annular main body 14. The groove 40B is in contact with the semipermeable membrane 20. Similar to the groove 40 described with reference to Figure 2, the groove 40B of this embodiment is a fine groove having a width that allows capillary force to act. When tear fluid 86 comes into contact with the groove 40B, the groove 40B can draw the tear fluid 86 into the entire groove 40B.
[0059] As shown in FIG. 7, when drug administration device 10E is positioned, a portion of main body 14 is positioned near tear meniscus 92. Water transport mechanism 24E (see FIG. 5) comes into contact with tear 86 at tear meniscus 92, thereby drawing tear 86 into semipermeable membrane 20. Therefore, drug administration device 10E of this embodiment can operate reliably even when semipermeable membrane 20 and needle tube 50 are placed at a location away from tear meniscus 92. In this way, drug administration device 10E of this embodiment enables stable administration operations while reducing the risk of eye infection.
[0060] (Seventh embodiment) A pharmaceutical administration device 10F of this embodiment shown in FIG. 8 differs from pharmaceutical administration device 10E described with reference to FIGS. 5 to 7 in a water transport mechanism 24F.
[0061] The water transport mechanism 24F of this embodiment has a semipermeable membrane member 48A. The semipermeable membrane member 48A is a strip-shaped member made of the same material as the semipermeable membrane 20 and is connected to the semipermeable membrane 20. The semipermeable membrane member 48A may be formed integrally with the semipermeable membrane 20. The semipermeable membrane member 48A is adhered to the outer peripheral surface 14d of the main body portion 14. In the illustrated example, the semipermeable membrane member 48A extends over a range corresponding to half the circumference of the main body portion 14, but it may also extend over the entire circumference of the main body portion 14.
[0062] As described with reference to Figure 7, this drug administration device 10F is attached to eyeball 84 with main body 14 surrounding cornea 82. Drug administration device 10F can draw tear 86 from tear meniscus 92 into semipermeable membrane 20 through semipermeable membrane member 48A. Therefore, drug administration device 10F can position semipermeable membrane 20 and the puncture position of needle tube 50 away from tear meniscus 92.
[0063] The present invention is not limited to the above disclosure, and various configurations may be adopted without departing from the spirit of the present invention. For example, the medicine administration device 10 may include both the semipermeable membrane member 48 and the groove portion 40 as the water transport mechanism 24. [Explanation of symbols]
[0064] 10, 10A, 10B, 10C, 10D, 10E, 10F...Medication administration device 12...medicine 14...main body 16...Partition wall 18...Discharge section 20...Semipermeable membrane 22...Pressure generating agent 24, 24A, 24B, 24C, 24D, 24E, 24F…Water transport mechanism 26...Cavity part 32...First chamber 34…Second room
Claims
1. a main body having a hollow portion therein; a partition wall that divides the cavity into a first chamber and a second chamber; A drug contained in the first chamber; an ejection portion provided in the first chamber and configured to eject the medicine; a pressure-generating agent accommodated in the second chamber, which expands upon contact with water to push the partition wall toward the first chamber; a semipermeable membrane provided in the second chamber and sealing the pressure-generating agent in the second chamber; A drug administration device comprising: a water transport mechanism that guides water from a site distant from the semipermeable membrane to the semipermeable membrane.
2. 2. The drug administration device according to claim 1, wherein the water transport mechanism has a fine flow path that utilizes capillary action to guide water to the semipermeable membrane.
3. 3. The drug administration device according to claim 2, wherein the microchannel is covered with a membrane made of a hydrophilic material.
4. 4. The drug administration device according to claim 2, wherein the fine flow channel includes a fine groove formed on an outer peripheral surface of the main body portion.
5. 5. The drug administration device according to claim 4, The main body portion has a membrane holding portion that holds the semipermeable membrane, The membrane holding portion has an opening into which the semipermeable membrane is inserted and an end surface surrounding the opening, The semipermeable membrane has a small diameter portion inserted into the opening and a large diameter portion having a diameter larger than that of the small diameter portion, the large diameter portion abuts against the end surface of the main body portion, A medicine administration device, wherein one end of the microgroove opens at the end surface of the main body portion.
6. 6. The drug administration device according to claim 5, The main body has a long cylindrical shape, the discharge portion is formed at one end of the main body portion in a longitudinal direction, The semipermeable membrane is formed at the other end of the main body in the longitudinal direction, The microgroove extends from the other end to the one end of the outer circumferential surface.
7. The drug administration device according to claim 1 , wherein the water transport mechanism includes a semipermeable membrane member extending from the semipermeable membrane.
8. The drug administration device according to claim 7 , wherein the semipermeable membrane member extends along the main body portion.
9. The drug administration device according to claim 8 , wherein the semipermeable membrane member is fixed to the main body portion.
10. 2. The drug delivery device of claim 1, wherein the semipermeable membrane comprises one of plasticized cellulose, hydroxyethyl methacrylate, polyurethane, polyamide, polyether-polyamide copolymer, and thermoplastic copolyester.
Citation Information
Patent Citations
Continuous administration of active agents using implantable systems
JP4176832B2