Injection needle and administration device

Abstract

[Problem] To reduce back pressure from subcutaneous tissue and thereby suppress injection resistance for a drug and pain during administration. [Solution] An injection needle 100 is attached to an administration device 200 which subcutaneously injects not less than 3 mL of a drug at an administration rate of not less than 3 mL / min, said injection needle comprising a body section 10 and a plurality of needle sections 20 which are provided to the body section 10, wherein the gap between the respective central axes of adjacent needle sections 20 is not less than ten times the inner diameter of the needle sections 20.

Description

Injection needle, administration device

[0001] The present invention relates to an injection needle and an administration device including the injection needle.

[0002] Antibody preparations are generally administered via intravenous injection as a common administration route. However, intravenous injection has the problem that the administration takes several hours. For this reason, from the viewpoint of convenience, the administration route of antibody preparations has shifted to subcutaneous injection, which can be administered in a relatively short time.

[0003] When an antibody preparation is subcutaneously administered, administration of a high dose of the drug is required. However, the amount of drug that can be subcutaneously administered is limited to about 1 ml to 2 ml. In addition, efforts have been made to concentrate the preparation in order to obtain a medicinal effect with a limited administration dose, but there is a limit to the concentration from the viewpoint of stability.

[0004] In recent years, as a technique for subcutaneous administration of high-dose drugs, a technique of using hyaluronidase, a hyaluronic acid-degrading enzyme, to form a space subcutaneously for subcutaneous injection of a large volume of drug solution has attracted attention. An antibody preparation (combination preparation) using hyaluronidase has an administration time of several minutes, which significantly reduces the administration time compared with intravenous injection, and enables large-volume subcutaneous administration. Furthermore, development of a technique for administering the combination preparation in one shot at a high speed (administration time of about 30 seconds) using an auto-injector is also progressing.

[0005] In addition, when subcutaneously administering a large volume of drug solution, from the viewpoint of shortening the administration time, it is also conceivable to use an injection device provided with a plurality of needles as disclosed in the following Patent Document 1.

[0006] Japanese Patent Application Laid-Open No. 2020-174978

[0007] When administering a large volume of drug solution at high speed via subcutaneous injection, the aforementioned subcutaneous injection using hyaluronidase can be a new administration method replacing intravenous injection, but it also has the following problems. The first problem is that when a large volume of drug solution is subcutaneously injected at a high speed, the injection resistance of the drug increases, and the time required to complete the administration is longer than the administration time (about 10 to 20 seconds) of a common auto-injector. The second problem is that high-speed administration of a large volume of drug solution may cause severe pain during administration.

[0008] All of the aforementioned problems are thought to be related to back pressure from the subcutaneous tissue into which the injection needle is inserted. However, current injection needles, including the device described in Patent Document 1, do not have the necessary measures to reduce back pressure during subcutaneous injection and resolve the aforementioned problems when administering large volumes of drug solution at high speed.

[0009] The present invention has been made in view of the above-mentioned problems, and specifically aims to provide an injection needle and administration device that can reduce back pressure from subcutaneous tissue and suppress drug injection resistance and pain during administration.

[0010] The present invention is achieved by any one of the following means (1) to (6).

[0011] (1) An injection needle for subcutaneous injection that administers 3 mL or more of a drug at a rate of 3 mL / min or more, comprising a main body and a plurality of needle portions provided on the main body, wherein the distance between the central axes of adjacent needle portions is 10 times or more the length of the inner diameter of the needle portion.

[0012] (2) The injection needle described in (1) above, wherein the spacing of the needle portions is arranged at equal intervals with respect to the main body portion.

[0013] (3) The injection needle according to (1) or (2) above, wherein the inner diameter of the needle portion is 0.064 mm or more and 0.460 mm or less.

[0014] (4) The injection needle according to any one of (1) to (3) above, wherein the needle portion has two to fifteen needles.

[0015] (5) The injection needle according to any one of (1) to (4) above, wherein the main body portion has a storage space for temporarily storing the drug that has flowed in from the administration device, and the storage space has a tapered portion that gradually widens in diameter from the proximal end to the tip in an axial cross-sectional view.

[0016] (6) An administration device comprising an injection needle as described in any one of (1) to (5) above, an outer cylinder having a drug-containing section for containing a drug, and a syringe having a tip section positioned on the tip side of the outer cylinder and connectable to the injection needle, wherein the injection needle has an opening at the tip of the needle section, and the syringe dispenses 3 mL or more of the drug contained in the drug-containing section from the opening of the injection needle at a rate of 3 mL / min or more.

[0017] According to the present invention, back pressure from the subcutaneous tissue can be reduced, thereby suppressing drug injection resistance and pain during administration.

[0018] This is a schematic perspective view showing the injection needle according to this embodiment. This is a schematic diagram showing the overall configuration of the injection needle. This is a cross-sectional view of the injection needle according to this embodiment. (a) and (b) are schematic diagrams to explain the spacing of the needle portion. This is a diagram showing an example of an administration device equipped with the injection needle according to this embodiment. This is a graph showing the relationship between the one-dimensional velocity of the fluid (drug) discharged from the needle portion and the distance between the central axes of the needle portion. This is a graph showing the relationship between the distance r from the tip of the needle portion and the one-dimensional velocity (ms) of the liquid at the position at distance r. This is a graph showing the test results of Test 1. This is a graph showing the test results of Test 2. This is a table showing the specifications of the sample and the test results of Test 2.

[0019] Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. The embodiments shown herein are illustrative examples for embodying the technical idea of ​​the present invention and do not limit the present invention. Furthermore, all other implementable forms, examples, and operational techniques that can be conceived by those skilled in the art without departing from the spirit of the present invention are included in the scope and spirit of the present invention, as well as in the claims and their equivalents.

[0020] Furthermore, the drawings attached to this specification may be schematically represented with changes to scale, aspect ratio, shape, etc., from the actual object for the sake of illustration and ease of understanding, but these are merely examples and do not limit the interpretation of the present invention.

[0021] In the following explanation, ordinal numbers such as "1st" and "2nd" are used, but unless otherwise specified, they are used for convenience and do not prescribe any particular order.

[0022] The injection needle 100 according to this embodiment will now be described. In the following description, the side of the injection needle 100 where the needle portion 20 is located on the main body portion 10 will be referred to as the tip side, and the side of the main body portion 10 where the administration device 200 is attached, opposite the needle portion 20 in the axial direction, will be referred to as the proximal end side.

[0023] As shown in Figures 1, 2A, and 2B, the injection needle 100 is composed of a main body 10, a needle portion 20, and a hub portion 30. The injection needle 100 is detachably attached to or integrally connected to the administration device 200 (see Figure 4). The injection needle 100 has a lumen 101 that is continuous from the tip to the proximal end.

[0024] As shown in Figures 1 and 2A, the main body 10 has a cylindrical shape with a storage space 11 for containing the drug formed inside. The needle portion 20 is located at the tip of the main body 10, and the hub portion 30 is located at the base end.

[0025] The containment space 11 communicates with the base end of the hub portion 30 at its base end and with the base end of the needle portion 20 at its tip end, and temporarily contains the drug that flows in from the hub portion 30. The containment space 11 can be formed in the shape of a frustocone, as shown in Figure 1. That is, as shown in Figure 2B, the containment space 11 is a trapezoid in an axial cross-sectional view, having a tapered portion 11a that gradually widens from the tip of the hub portion 30. The containment space 11 has a tapered portion 11a that gradually widens from the base end to the tip end, which can reduce injection resistance. The containment space 11 temporarily contains the drug that flows in through the hub portion 30 and then allows it to flow directly to the individual needle portions 20. The containment space 11 constitutes a part of the lumen 101.

[0026] When the injection needle 100 delivers the drug solution directly from the hub portion 30 to the individual needle portions 20, the following problems 1 and 2 may occur. Problem 1 is that the inner diameter of the hub portion 30 becomes small, making it difficult to secure the distance L1 between the central axes of the needle portions 20, which will be described later. Problem 2 is that in order to adjust the spacing of the needle portions 20 to the distance L1, for example, a narrow-diameter flow path must be connected from the hub portion 30 to the needle portions 20, which may cause pressure loss due to the narrow-diameter flow path and increase the injection resistance. Furthermore, when the housing space 11 of the injection needle 100 is a simple rectangular parallelepiped, the following problems 3 and 4 may occur. Problem 3 is that when the drug solution moves from the hub portion 30 to the housing space 11, the outlet pressure loss becomes large. Problem 4 is that depending on the viscosity of the formulation and the administration rate, turbulence may occur, which may increase the injection resistance.

[0027] In contrast, as shown in Figure 2B, if the injection needle 100 of this embodiment has a frustoconical shape with a tapered portion 11a that gradually widens in diameter from the tip of the hub portion 30 in an axial cross-sectional view, it is not necessary to provide a small-diameter flow path connecting the hub portion 30 and the needle portion 20 in each needle portion 20, and a sufficient distance L1 can be secured as the spacing between the needle portions 20, so that the injection resistance does not increase. Furthermore, since the housing space 11 of the injection needle 100 has a frustoconical shape in an axial walking cross-sectional view, the outlet pressure loss when the drug solution moves from the hub portion 30 to the housing space 11 can be reduced, while the generation of turbulence can be suppressed, thereby suppressing the increase in injection resistance.

[0028] Multiple needle portions 20 are arranged on the main body portion 10. As shown in Figure 2B, a portion of the base end of the needle portion 20 is embedded in the main body portion 10, while the remaining portion is exposed from the main body portion 10. In this embodiment, three needle portions 20 are provided at predetermined intervals.

[0029] The needle portion 20 has a lumen 21 that communicates from the tip to the base, with the base communicating with the housing space 11. As shown in Figure 1, the lumen 21 of the needle portion 20 is part of the lumen 101 of the injection needle 100. A needle tip portion 22, which functions as a puncture area, is formed on the tip side of the needle portion 20.

[0030] The needle tip portion 22 is the part that punctures the target of administration, and its tip shape is formed by a sharp cutting surface created through a general processing process such as a lancet cut or back cut. In this embodiment, as shown in Figure 1, the needle tip portion 22 is formed with an opening 23 for dispensing the drug that opens in the axial direction.

[0031] Figure 3(a) shows the distance L1 between the central axes of the needle portion 20 of the injection needle 100, and Figure 3(b) shows the inner diameter r of the needle portion 20. In order to reduce back pressure from the subcutaneous tissue, the needle portion 20 is arranged such that the distance L1 between the central axes of adjacent needle portions 20 is at least 10 times the inner diameter r of the needle portion 20, as shown in Figures 3(a) and (b). As shown in Figure 3(a), the injection needle 100 is arranged such that the distance L1 between the central axes of adjacent needle portions 20 is at least 10 times the inner diameter r of the needle portion 20, thereby reducing back pressure and suppressing injection resistance and pain during administration that can be affected by back pressure.

[0032] The distance L1 between the central axes of the needle portions 20 is preferably 2.8 mm or more, which is 10 times the inner diameter, in the case of a 27G needle (outer diameter: 0.41 mm, inner diameter: 0.28 mm). This distance L1 is such that the drugs dispensed from the needle portions 20 do not interfere with each other, or the degree of interference is extremely low. The lower the degree of interference between the drugs dispensed from adjacent needle portions 20, the less injection resistance there is and the smoother the dispensing. Therefore, the longer the distance L1 between the needle portions 20, the greater the effect of reducing back pressure.

[0033] Here, the reason for setting the distance L1 between the needle portions 20 will be explained using the following equations (1) to (6).

[0034]

[0035]

[0036]

[0037]

[0038]

[0039]

[0040]

[0041]

[0042] When there is one needle, the liquid velocity in the tissue is inversely proportional to the square of the distance r from the tip of the needle portion 20, as shown in (Formula 1) above. In (Formula 1), v(r) is the one-dimensional velocity (m / s) of the liquid at distance r from the tip of the needle portion 20, and q is the volume flow rate of the liquid discharged from the needle portion 20 (m ３ / s), k is the permeability coefficient of the tissue, and r is the distance (mm) from the tip of the needle portion 20.

[0043] (Formula 2) above is obtained by expressing (Formula 1) in vector notation. As shown in FIG. 5A, when liquid at q (m ３ / s) is discharged from two needle portions 20 (needle portion A and needle portion B respectively) located at the origin and a position separated from the origin by R, the combined vector v of the liquid velocity at position r (point P) α (r) can be expressed as shown in (Formula 3) above.

[0044] In a space where the velocity field v(r) can be defined according to Darcy's law, the pressure p(r) at a given position r can be expressed as (Formula 4) above. Substituting (Formula 3) above into (Formula 4) above gives (Formula 5) above. Here, the first term is equivalent to the expression for backpressure when there is one needle. When |R|>20d (d is the inner diameter of the needle portion 20), |R-r|<10d is satisfied, so the calculation result of the second term is 1 / 100 or less of the calculation result of the first term. Therefore, if the second term of (Formula 5) is ignored, the backpressure does not change from that when there is one needle portion 20, resulting in (Formula 6) above.

[0045] Combining (Formula 6) above with the Hagen-Poiseuille equation gives (Formula 7) above. As is clear from (Formula 7) above, since it is linear with respect to the flow rate q and the viscosity μ, (Formula 7) above holds regardless of the type and viscosity of the drug, and the approximation of the third term of (Formula 5) above also holds in the same manner.

[0046] Figure 5B is a graph showing the relationship between the distance r from the tip of the needle portion 20 and the one-dimensional velocity (ms) of the liquid (drug) at the position at distance r. １ The symbol '' indicates the inner diameter of the needle portion 20. As shown in Figure 5B, the flow velocity at a distance of 10 times the distance between the needle portions 20 is about 1% of the flow velocity at the tip of the needle portion 20. This indicates that when the distance L1 between the central axes of the needle portions 20 is 10 times the inner diameter r of the needle portion 20, the liquid (drug) discharged from each of the needle portions 20 hardly interferes with each other.

[0047] Furthermore, back pressure is the volumetric flow velocity (m) of the liquid (chemical) discharged from a single needle section 20. ３ Since it is proportional to ( / S), if the injection needle 100 is formed with multiple needle sections 20 instead of a single needle, the volume flow velocity (m) of the liquid (drug) for each needle section 20 will be proportional to (m) as obtained from (Equation 8) above. ３ The (S) is reduced, thereby reducing back pressure. In (Equation 8), p is the back pressure (Pa), and q is the volumetric flow velocity (m) of the liquid (chemical) discharged from one needle 20. ３ The formula is ( / S), where k is the tissue permeability coefficient and r is the inner diameter (mm) of the needle portion 20.

[0048] As described above, in the injection needle 100, if the needle portion 20 is made into multiple needle portions 20, and the spacing between the needle portions 20 (the spacing between the central axes of the needle portions 20) is set to a distance L1 of 10 times or more the inner diameter r of the needle portion 20 (i.e., a distance at which the liquid (drug) discharged from the needle portion 20 does not interfere with each other), the back pressure that may be related to injection resistance and pain during administration is reduced, and injection resistance and pain during administration can be suppressed.

[0049] From the viewpoint that improper force distribution during puncture may occur, it is preferable to arrange the needle portions 20 relative to the main body 10 so that the distance between adjacent needle portions 20 is equal. Similarly, it is also preferable to make the lengths of the needle portions 20 the same to suppress the possibility of improper force distribution during puncture and the occurrence of improper puncture. Here, improper puncture means, for example, that the force is not applied properly to one needle portion 20, and that it only reaches the intradermal layer, so that the openings 23 of all needle portions 20 do not reach the appropriate administration position.

[0050] From the viewpoint of needle gauges used for subcutaneous injection, the inner diameter r of the needle portion 20 is preferably 0.064 mm or more and 0.460 mm or less.

[0051] The needle portion 20 is formed such that it protrudes axially from the tip surface of the main body portion 10 toward the tip (exposed length L2) so that the main body portion 10 comes into contact with the skin and the subject, and at the same time the opening 23 of the injection needle 100 reaches the target injection position. For this reason, the needle portion 20 can be formed to protrude from the main body portion 10 by a length of 3 mm to 6 mm, for example, in the case of subcutaneous injection.

[0052] From the viewpoint of reducing back pressure and minimizing invasiveness, it is preferable that the number of needle portions 20 be between two and fifteen.

[0053] The hub portion 30 is formed in a cylindrical shape and has a lumen 31 that extends from the tip to the base. The hub portion 30 is positioned at the base of the main body portion 10. The lumen 31 of the hub portion 30 communicates with the housing space 11 and constitutes a part of the lumen 101 of the injection needle 100.

[0054] The hub portion 30 has a connecting portion 32 on its base end. The connecting portion 32 is configured to be connectable to the tip portion 220 of the administration device 200. For example, if the administration device 200 is configured as a syringe with a Luer taper or Luer lock tip portion 220, the connecting portion 32 can be configured to match the shape of the tip portion 220. In this embodiment, since the tip portion 220 of the administration device 200 shown in Figure 4 is of the Luer lock type, the connecting portion 32 has a shape that corresponds to the Luer lock type.

[0055] Furthermore, there are no particular restrictions on the shape or other aspects of the connecting portion 32, as long as it is configured to be detachable from the administration device 200. Also, the connecting portion 32 may be integrally connected to the tip portion 220 of the administration device 200.

[0056] The administration device 200 is a device capable of delivering a drug to the injection needle 100. The administration device 200 has the function of containing 3 mL or more of a drug in the drug storage section 211 and subcutaneously injecting 3 mL or more of the drug from the injection needle 100 connected to the tip section 220 at an administration rate of 3 mL / min or more. As shown in Figure 4, the administration device 200 can be composed of a syringe having an outer cylinder 210 and a tip section 220 positioned on the tip side of the outer cylinder 210 to which the injection needle 100 can be attached.

[0057] The outer cylinder 210 has a lumen that extends from the tip to the base, and a drug storage section 211 is formed therein that can hold 3 mL or more of drug. A plunger 230 is mounted on the outer cylinder 210 so as to be axially slidable relative to the drug storage section 211. The plunger 230 has a gasket 240 attached to its tip that substantially matches the inner diameter of the drug storage section 211. The drug stored in the drug storage section 211 is delivered to the needle portion 20 of the injection needle 100 by the movement of the plunger 230 toward the tip.

[0058] Furthermore, the administration device 200 is not limited to a syringe, and other devices capable of functioning as the administration device 200 may be used. In addition, subcutaneous injection into the recipient using the administration device 200 may be performed by the operator directly operating the administration device 200, or it may be performed automatically using an automatic injector such as an autoinjector.

[0059] Next, a method of administering a drug using an administration device 200 equipped with an injection needle 100 will be described. In this embodiment, the injection needle 100 is connected to an administration device 200 that can administer a large volume of drug solution of 3 mL or more and the drug contained through the injection needle 100, thereby reducing back pressure during subcutaneous injection and enabling administration with reduced injection resistance and pain during administration.

[0060] The administration method involves first preparing the administration device 200 by filling the drug container 211 of the administration device 200 with the drug. Next, attaching the injection needle 100 according to this embodiment to the tip 220 of the administration device 200. Then, subcutaneously puncturing the target with the needle portion 20 of the injection needle 100 attached to the administration device 200. Next, while the injection needle is inserted into the subcutaneous tissue, the plunger 230 of the administration device 200 is operated to administer 3 mL or more of the drug contained in the administration device 200 through the opening 23 of the needle portion 20 of the injection needle 100 at a rate of 3 mL / min or more. Since the administration device 200 is used for subcutaneous injection through the injection needle 100, back pressure during subcutaneous injection is reduced, and administration can be performed with reduced injection resistance and pain during administration.

[0061] Furthermore, since the administration method using the administration device 200 only requires that 3 mL or more of the drug be administered at a rate of 3 mL / min or more, the operator may administer the drug by operating the administration device 200, or an automatic injector such as an auto-injector may be used.

[0062] The drug (substance) administered into the subcutaneous tissue through the opening 23 of the needle portion 20 of the injection needle 100 according to this embodiment can, for example, be an antibody preparation containing hyaluronidase or a general antibody preparation without hyaluronidase. The drug is not particularly limited as long as it is administered by subcutaneous injection, is available in a large volume of 3 mL or more, and can be administered at an administration rate of 3 mL / min or more.

[0063] As described above, the injection needle 100 according to this embodiment is an injection needle for subcutaneous injection that administers 3 mL or more of a drug at a rate of 3 mL / min or more, and comprises a main body portion 10 and a plurality of needle portions 20 provided on the main body portion 10, wherein the distance L1 between the central axes of adjacent needle portions 20 is 10 times or more the length of the inner diameter r of the needle portion 20.

[0064] With this configuration, the injection needle 100 has a distance L1 between the central axes of adjacent needle portions 20 that is 10 times or more the length of the inner diameter r of the needle portion 20. As a result, back pressure is reduced when a large volume of drug solution of 3 mL or more is administered subcutaneously at a high speed of 3 mL / min or more, thereby suppressing injection resistance and pain during administration.

[0065] The effects of the present invention will be explained using the following examples and comparative examples. However, the technical scope of the present invention is not limited to the following examples.

[0066] [Test 1] Test 1 is a test that compares the injection resistance and back pressure of an example (multi-needle) and a comparative example (single-needle) having equivalent needle cross-sectional areas. The cross-sectional areas of the needles in the example and comparative example were selected to be approximately the same.

[0067] <Sample Specifications> The sample injection needles for the example and comparative example of Test 1 had the following configurations: Example: A multi-needle with three needle sections, each consisting of a 27G extra-thin wall needle (inner diameter: total of 3 needles 0.320 mm), with a distance of 9 mm between the central axes of each needle. Comparative Example: A single needle with one needle section consisting of a 23G regular wall needle conforming to ISO 9626:2016(E) standards (inner diameter: 0.317 mm to 0.390 mm).

[0068] <Test Conditions> The test conditions for Test 1 were as follows: • Drug: Hyaluronidase-containing CMC (carboxymethylcellulose) solution (2000 U / mL) • Viscosity: 4.5 cP • Discharge rate: 30 mL / min • Syringe (administration device): 20 mL lockable Terumo syringe (manufactured by Terumo Corporation) • Discharge volume: 10 mL • Subject: Abdominal tissue of livestock pigs (subcutaneous tissue + muscle layer), body weight ≈ 60 kg, sex: male (castrated), quantity: 1 head • Measurement device: Universal testing machine "EZ-test" (manufactured by Shimadzu Corporation).

[0069] <Test Method> The test method for Test 1 was carried out as follows. First, as preparation of the test specimens, abdominal tissue was collected from euthanized livestock pigs. Next, the drug was filled into syringes, and the injection needles of each sample were attached to the tips of the syringes. Next, the syringes were set in a universal testing machine, and the needles of each sample were pressed against the pig's abdominal tissue to visually confirm that puncture had occurred. Next, the measuring device was activated, and a specified amount was discharged at a specified discharge rate with the needles still inserted into the pig's abdominal tissue. The maximum value measured by the testing machine was defined as the injection resistance value, and the value measured when discharged into the air without puncture was defined as the discharge resistance value. The difference between the injection resistance value and the discharge resistance value was defined as the back pressure.

[0070] <Results> The test results are shown in Figure 6. In the results for each sample, the left side shows the injection resistance value, and the right side shows the back pressure. As shown in Figure 6, it was confirmed that the injection resistance and back pressure of the example were lower than those of the comparative example. From these results, it was found that back pressure can be reduced by having multiple needle sections, as in the injection needle according to the present invention, and by making the distance between the central axes of adjacent needle sections 10 times or more the inner diameter of the needle section. Therefore, it is considered that the injection needle of the present invention can be used to suppress injection resistance and pain during administration, which may be related to back pressure, when administering a large volume of drug solution at high speed.

[0071] [Test 2] Test 2 was a test to measure the injection resistance when the spacing of the needles was changed. The cross-sectional area of ​​the needles in the example and comparative example were selected to be approximately the same, as in Test 1.

[0072] <Sample Specifications> The sample injection needles used in the examples and comparative examples in Test 2 had the following configuration: Example 1, Example 2, Comparative Example A; The needle section consisted of three 27G extra-thin wall needles (inner diameter: 0.320 mm), with the distance between the central axes of each needle being 2 mm (Comparative Example A), 5 mm (Example 1), and 9 mm (Example 2). Multi-needle extension tube (manufactured by Terumo Corporation).

[0073] <Test Conditions> The test conditions for Test 2 were as follows: • Reagents used: Water for injection (collected from Terumo Corporation's in-house facilities), L-Histidinine (manufactured by Kanto Chemical Co., Ltd.), NaCl (manufactured by Nacalai Tesque Co., Ltd.), sheep testis-derived hyaluronidase (manufactured by Fujifilm Wako Pure Chemical Industries Ltd.) • Syringe (administration device): 20 mL lockable Terumo syringe (manufactured by Terumo Corporation) • Administration rate: 90 mm / min (a rate at which the drug can be administered at a rate of 30 mL / min) • Dosage: 10 mL • Prepared drug: Solvent: Water for injection, Solute: 10 mM L-Histidinine, 130 mM NaCl, Active ingredient: 2000 Units / ml Hyaluronidase (- / +) • Measurement device: Universal tester "EZ-SX 500N" (manufactured by Shimadzu Corporation) Target subjects: Abdominal tissue (subcutaneous tissue + muscle layer) of domestic pigs, body weight ≈ 60 kg, sex: male (castrated), quantity: 2 pigs.

[0074] <Test Method> The test method for Test 2 was carried out as follows. First, as preparation of the test specimen, abdominal tissue was collected from euthanized livestock pigs. Next, a solute was dissolved in sterile water for injection to a concentration of 10 mM L-Histidinine and 130 mM NaCl to prepare a (hyaluronidase (-) solution). In addition, hyaluronidase was dissolved in the above solution to a concentration of 2000 U / ml to prepare a (hyaluronidase (+) solution). Next, each prepared drug was individually filled into a syringe, and the extension tube and the injection needle of each sample were connected and the inside was primed. Next, each syringe filled with each drug was individually set in the measuring device, and the needle of each sample was pressed against the abdominal tissue of the pig to visually confirm that puncture had occurred. Then, the measuring device was activated and the drugs were administered. The experiment was performed three times for each sample (n=3).

[0075] <Results> The test results are shown in Figures 7 and 8. In Figure 7, the result for (hyalronidase(-) solution) is shown as Hyl(-), and the result for (hyalronidase(+) solution) is shown as Hyl(+). The dotted line in Figure 7 indicates the threshold of 10 times the inner diameter of the needle portion in the multi-needle sample. As shown in Figure 7, when the threshold of 10 times the inner diameter of the needle portion is used as the boundary, both Example 1 and Example 2, which satisfy the threshold of 10 times or more the inner diameter of the needle portion, showed reduced injection resistance compared to Comparative Example A, which does not satisfy the threshold of 10 times the inner diameter of the needle portion. From these results, it is considered that, in the injection needle according to the present invention, if the needle portion is made up of multiple needle portions and the distance between the central axes of adjacent needle portions is 10 times or more the inner diameter of the needle portion, the back pressure of the needle portion is reduced and the injection resistance is suppressed.

[0076] This application is based on Japanese Patent Application No. 2025-047667, filed on 24 March 2025, the disclosures of which are cited in their entirety by reference.

[0077] 10 Main body, 11 Storage space, 11a Tapered section, 20 Needle section, 21 Lumen of the needle section, 22 Needle tip section, 23 Opening, 30 Hub section, 31 Lumen of the hub section, 32 Connection section, 100 Injection needle, 101 Lumen, 200 Administration device, 210 Outer barrel, 211 Drug storage section, 220 Tip section, 230 Plunger, 240 Gasket, L1 Distance between the central axes of the needle section, L2 Length of the needle section exposed from the main body section, r Inner diameter of the needle section.

Claims

1. An injection needle for subcutaneous injection that administers 3 mL or more of a drug at a rate of 3 mL / min or more, comprising a main body and a plurality of needle portions provided on the main body, wherein the distance between the central axes of adjacent needle portions is 10 times or more the length of the inner diameter of the needle portions.

2. The injection needle according to claim 1, wherein the needle portions are arranged at equal intervals with respect to the main body portion.

3. The injection needle according to claim 1, wherein the inner diameter of the needle portion is 0.064 mm or more and 0.460 mm or less.

4. The injection needle according to claim 1, wherein the needle portion comprises two to fifteen needles.

5. The injection needle according to claim 1, wherein the main body portion has a storage space for temporarily storing the drug that has flowed in from the administration device, and the storage space has a tapered portion that gradually widens in diameter from the proximal end to the tip in an axial cross-sectional view.

6. An administration device comprising: an injection needle according to any one of claims 1 to 5; a syringe having an outer cylinder formed with a drug-containing section for containing the drug; and a tip section disposed on the tip side of the outer cylinder and connectable to the injection needle, wherein the injection needle has an opening at the tip of the needle portion, and the syringe dispenses 3 mL or more of the drug contained in the drug-containing section from the opening of the injection needle at a rate of 3 mL / min or more.

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