Injection needle

Abstract

The injection needle (1A) of the present invention has a protrusion protruding from a sheet base (2), the protrusion including a first protrusion (31) having an opening (31a) at the front end and being hollow, and a second protrusion (32) having no opening at the front end, and a puncture depth control portion (40) at an intermediate position, the intermediate position being a position lower than the front end position of the first protrusion (31) and higher than the surface of the sheet base (2). Preferably, the height difference between the front end position of the first protrusion (31) and the position of the puncture depth control portion (40) is 1 μm or more and 5000 μm or less.

Description

Technical Field

[0001] The present invention relates to injection needles. Background Art

[0002] In recent years, in the medical field, the beauty field, etc., the technology of transdermal absorption of liquids such as drugs using liquid injection devices having fine needle-like protrusions also called microneedles has attracted much attention. With this liquid injection device, the microneedles can penetrate the shallower layers of the skin such as the stratum corneum to inject liquid into the body, which can greatly reduce the pain felt by the subject compared to the usual syringe, and therefore has attracted much attention as a low-invasive liquid administration device.

[0003] A kind of fine protrusion utensil is recorded in patent document 1, and it has a needle-shaped and hollow first protrusion formed from the upper surface of one side of the substrate sheet which is circular in top view, and a hollow second protrusion formed near the first protrusion in the upper surface of the substrate sheet and having a protruding height lower than the first protrusion. In the document, it is recorded that when the first protrusion is pierced into the skin from the front end side, the piercing of the first protrusion stops at the moment when the front end of the second protrusion near it contacts the surface of the skin, which can prevent the first protrusion from piercing into the deeper part of the skin. An opening is formed at the front end of the first protrusion, and the hollow part of the first protrusion is connected with the outside via the opening. In addition, it is recorded in the document that the front end of the first protrusion is pierced into the skin, and the liquid-like medicament stored in the hollow part of the first protrusion is injected into the skin from the opening of the front end.

[0004] Patent Document 2 describes a microneedle sheet having a plurality of micro-sized needle groups protruding from the surface. The document describes that the needle group includes a through needle group having through holes penetrating from the surface side to the back side, and a dummy needle group having no through holes.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent document 1: US2018185624A1

[0008] Patent Document 2: International Publication No. 2021 / 177317 Summary of the invention

[0009] The present invention provides an injection device having a protrusion protruding from a sheet base.

[0010] The injection needle of the present invention preferably includes, as the protrusion, a first protrusion having an opening at a tip end portion and being hollow, and a second protrusion having no opening at a tip end portion.

[0011] The injection needle of the present invention preferably has a puncture depth control portion at an intermediate position, wherein the intermediate position is a position lower than the tip position of the first projection and higher than the surface of the sheet base. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a cross-sectional view along the thickness direction of an injection needle according to a preferred embodiment of the present invention.

[0013] Figure 2 yes Figure 1 A top view of the injection needle is shown.

[0014] Figure 3 It is schematically indicated Figure 1 The figure showing the injection needle in use shows a state in which the first protrusion of the injection needle pierces the stratum corneum of the skin and the puncture depth control part does not pierce the skin but contacts the skin surface.

[0015] Figure 4 It is an explanatory diagram showing a method of measuring the tip diameter of a protrusion in an injection needle.

[0016] Figure 5 (a) to (e) are schematic representations of Figure 1 A top view of the arrangement pattern of protrusions in the injection needle is shown.

[0017] Figure 6 is a cross-sectional view showing another preferred embodiment of the present invention, corresponding to Figure 1 .

[0018] Figure 7 It is schematically indicated Figure 6 The diagram of the injection needle in use corresponds to Figure 3 .

[0019] Figure 8 It is schematically indicated Figure 6 A top view of the arrangement pattern of protrusions in the injection needle is shown.

[0020] Fig. 9 is a cross-sectional view showing another preferred embodiment of the present invention, corresponding to Figure 1 .

[0021] Fig.10 It is schematically indicated Fig. 9 The diagram of the injection needle in use corresponds to Figure 3 .

[0022] Fig.11 It is schematically indicated Fig. 9 A top view of the arrangement pattern of protrusions in the injection needle is shown.

[0023] Fig.12 (a) is a cross-sectional view schematically showing a modified example of the composite primary protrusion and the composite secondary protrusion. Fig.12 (b) is a cross-sectional view schematically showing a deformation example of the second protrusion.

[0024] Fig.13 (a) is a cross-sectional view along the thickness direction of the injection needle of Comparative Example 1, Fig.13 (b) is a plan view schematically showing the arrangement pattern of protrusions in the injection needle of Comparative Example 1.

[0025] Fig.14 (a) is a top view schematically showing the arrangement pattern of protrusions in the injection needle of Example 5, Fig.14 (b) is a top view schematically showing the arrangement pattern of protrusions in the injection needle of Example 6, Fig.14 (c) is a plan view schematically showing the arrangement pattern of protrusions in the injection needle of Example 7. DETAILED DESCRIPTION

[0026] In the fine protrusion device of patent document 1, the protrusions of the fine protrusion device are composed of a first protrusion portion that is hollow and has an opening and a second protrusion portion that is lower in protrusion height than the first protrusion portion. Only the first protrusion portion pierces the skin, and the second protrusion portion that is lower in protrusion height than the first protrusion portion acts as a stopper to limit the penetration depth of the first protrusion portion. Therefore, in the fine protrusion device of this document, the blood flow promotion effect caused by the protrusion being pressed or pierced into the skin is restrictive and there is room for improvement. In particular, as a protrusion that can provide skin stimulation, only the first protrusion is disclosed, and there is no disclosure of increasing its density or imparting a blood flow promotion effect uniformly over a large range.

[0027] Patent Document 2 does not describe the puncture depths of the penetration needle group and the dummy needle group.

[0028] The invention relates to an injection needle which can control the depth of piercing the skin, can inject liquid and can effectively promote blood flow.

[0029] Hereinafter, the present invention will be described with reference to preferred embodiments of the present invention.

[0030] The injection needle 1A of the present invention has a protrusion protruding from the sheet base 20 .

[0031] Typically, the injection needle 1A of the present invention has a flat sheet-like shape as a whole, and includes a sheet base 2 and a plurality of protrusions protruding from one surface of the sheet base 2 .

[0032] Typically, the injection needle 1A of the present invention has a protrusion arrangement region where protrusions are arranged in a dispersed state in a planar direction. The shape of the protrusion arrangement region can be any shape such as a quadrilateral such as a square or rectangle, a polygon such as a circle, an ellipse, a pentagon, or a hexagon.

[0033] The protrusions of the injection needle 1A preferably include a first protrusion 31 having an opening 31a at the tip and being hollow, a second protrusion 32 having no opening at the tip, and a third protrusion 33 having a height lower than that of either the first protrusion 31 or the second protrusion 32. The first protrusion 31 is a fine protrusion having a hollow portion 31b, i.e., a so-called microneedle.

[0034] The second protrusion 32 and the third protrusion 33 may be hollow or solid. In the first embodiment, the second protrusion 32 and the third protrusion 33 are solid. Since the second protrusion 32 and the third protrusion 33 are solid, when the drug is injected from the injection needle 1A of the present invention, the drug remaining in the injection needle 1A can be reduced.

[0035] Furthermore, it is preferred that the front end surface of the third protrusion 33 is flat, that is, has a straight line shape extending in the horizontal direction, or has a curved line protruding in the protruding direction of the third protrusion.

[0036] The injection needle of the present invention preferably has a puncture depth control portion 40 at an intermediate position that is lower than the tip position of the first protrusion 31 and higher than the surface of the sheet base 20. Typically, the tip surface of the third protrusion 33 serves as the puncture depth control portion 40. Figure 1 An example is shown in FIG.

[0037] The puncture depth control unit 40 controls the puncture depth of the first projection 31. The puncture depth control unit 40 is preferably located at a position lower than the tip of the second projection 32.

[0038] In the injection needle 1A of the present invention, it is preferable that a plurality of second protrusions 32 are formed around one first protrusion 31. It is preferable that the second protrusions 32 are at the same distance from the first protrusion 31.

[0039] In the injection needle 1A of the present invention, it is preferable that a plurality of third protrusions 33 are formed around one first protrusion 31. It is preferable that the third protrusions 33 are at the same distance from the first protrusion 31.

[0040] More specifically, it is preferred that a pair of second protrusions 32, 32 are arranged in a manner that the first protrusion 31 is sandwiched between them in the first direction X, and a pair of second protrusions 32, 32 are arranged in a manner that the first protrusion 31 is sandwiched between them in the second direction Y that is orthogonal to the first direction X. In addition, it is preferred that a pair of third protrusions 33, 33 are arranged in a manner that the first protrusion 31 is sandwiched between them in the first direction X, and in addition, a pair of third protrusions 33, 33 are arranged in a manner that the first protrusion 31 is sandwiched between them in the second direction Y. The third protrusion 33 is preferably arranged between the first protrusion 31 and the second protrusion 32. Figure 2 An example thereof is shown in FIG. 1 . In addition, the position of the second protrusion 32 and the position of the third protrusion 33 may also be opposite. That is, the second protrusion 32 may be arranged between the first protrusion 31 and the third protrusion 33.

[0041] In the injection needle 1A of the present invention, it is preferred that a plurality of unit arrangement patterns including first protrusions 31, second protrusions 32 and third protrusions 33 arranged in a predetermined positional relationship are continuously arranged in the first direction X and the second direction Y in such a manner that adjacent unit arrangement patterns share the second protrusion 32.

[0042] Typically, in the injection needle 1A of the present invention, the first protrusion 31 and the second protrusion 32 are conical, and the third protrusion 33 is cylindrical. More typically, the plurality of second protrusions 32 are of the same shape and size, and the plurality of third protrusions 33 are also of the same shape and size.

[0043] The injection needle 1A preferably contains a thermoplastic resin. Specifically, it is preferred that the base material constituting the injection needle contains a thermoplastic resin. Typically, the injection needle 1A is preferably formed by plastically deforming a base sheet containing a thermoplastic resin by heating. The heating method of the base sheet may be a method of heating only a portion of the base sheet or a method of heating the entire base sheet. As a method of plastically deforming the base sheet by heating only a portion of the base sheet, there can be cited a method of inserting a processing needle while applying ultrasonic vibration to a predetermined position for forming a protrusion in the base sheet, a method of inserting a heated processing needle into a predetermined position for forming a protrusion in the base sheet, and the like. As a method of plastically deforming the base sheet by heating the entire base sheet, there can be cited a method of inserting a processing needle into a predetermined position for forming a protrusion in the base sheet while heating the entire base sheet using a heating device such as a heater, and the like.

[0044] In order to make the second protrusions 32 and the third protrusions 33 solid, for example, the hollow portion of the hollow second protrusion or the third protrusion formed by piercing a processing needle into the base sheet may be filled with the resin forming the protrusion or other resins.

[0045] The injection needle 1A of the present invention preferably has an opening 31a in the first protrusion 31. Thus, the injection needle 1A of the present invention becomes a liquid injection device that can be used for percutaneous absorption of liquid such as a drug.

[0046] Typically, an opening 31a is formed at the front end of the first protrusion 31, and the hollow portion 31b of the first protrusion 31 is connected to the outside through the opening 31a. The opening 31a is preferably a through hole that penetrates the sheet base 2 forming the first protrusion 31 in the thickness direction, and is located at the front end of the conical first protrusion 31. The hollow portion 31b of the first protrusion 31 functions as a storage portion or passage for liquid discharged from the opening 31a to the outside. Here, the front end of the first protrusion 31 refers to a region closer to the tip side than the middle position of the protrusion height H1 from the surface of the sheet base 2 to the tip of the first protrusion 31.

[0047] When the injection needle 1A is used for percutaneous absorption of a drug, the tip of the first protrusion 31 is inserted into the skin S, and the liquid drug L stored in the hollow portion 31b of the first protrusion 31 is injected from the opening 31a of the tip into the skin S. Typically, when no drug is supplied from the outside, the hollow portion 31b of the first protrusion 31 functions as a drug storage portion in this manner.

[0048] When a drug is supplied from the outside, for example, when a drug supply device such as an applicator (not shown) is used together with the injection needle 1A, the hollow portion 31b functions as a passage for the drug. The drug supply device may also be provided with a sheet member on the back side of the injection needle 1A, a drug storage space is formed between the back side of the injection needle 1A and the sheet member, and the drug is supplied to the first protrusion 31 by pressing the sheet member (see Japanese Patent Publication No. 2020-096790

[0011] ).

[0049] The injection needle 1A preferably has a second protrusion 32 in addition to the first protrusion 31 .

[0050] When the height H2 of the second protrusion 32 is higher than the height H3 of the puncture depth control part 40, when the injection needle 1A is pressed against the skin and the first protrusion 31 is inserted into the skin from the front end side, the second protrusion 32 also inserts into the skin. When the second protrusion 32 inserts into the skin, the second protrusion 32 stimulates the skin and plays a role in promoting blood flow. Thus, according to the injection needle 1A having this structure, the first protrusion 31 can be used to inject liquid into the skin, and the second protrusion 32 can be used to promote blood flow. Unlike the fine protrusion device of Patent Document 1, in which the protrusion of the fine protrusion device is only the first protrusion part that can inject liquid into the skin, in the injection needle 1A, both the first protrusion 31 and the second protrusion 32 can be used to stimulate the skin over a wide range. Therefore, unlike the fine protrusion device of patent document 1, in which only the first protrusion is added in order to stimulate the skin over a large area, when the injection needle 1A is applied to the skin, even if there is a part of the protrusion that does not pierce the skin, it is not necessarily the first protrusion with an opening, so the probability of liquid leakage can be suppressed.

[0051] When the injection needle 1A is pressed against the skin, the second protrusion 32 may be pressed against the skin without piercing the skin. Typically, the height H2 of the second protrusion 32 is equal to the distance H3 from the surface of the sheet base 2 to the puncture depth control unit 40. In this case, the second protrusion 32 can also stimulate the skin and promote blood flow.

[0052] In addition, the injection needle 1A preferably has a puncture depth control unit 40 in addition to the first protrusion 31 and the second protrusion 32. As described above, in the injection needle 1A, the front end surface of the third protrusion 33 is preferably the puncture depth control unit 40. When the first protrusion 31 and the second protrusion 32 are inserted into the skin from the front end side, the puncture depth control unit 40 contacts the surface of the skin, and the insertion of the first protrusion 31 and the second protrusion 32 is stopped, so that the first protrusion 31 and the second protrusion 32 can be prevented from piercing deeper into the skin. That is, the puncture depth control unit 40 functions as a limiter that limits the insertion depth of the first protrusion 31 and the second protrusion 32.

[0053] exist Figure 3 An example having these structures is shown in FIG.

[0054] The presence or absence of the blood flow promoting effect can be determined by various known methods, for example, by determining whether a flare reaction occurs on the skin, or by visualizing the blood flow distribution using a laser blood flowmeter (LSFG).

[0055] As described above, the injection needle 1A can control the penetration depth of the first protrusion 31 and the second protrusion 32 into the skin, thereby enabling the drug to be percutaneously absorbed at any depth of the skin and effectively promoting blood flow. Therefore, according to the injection needle 1A, by adjusting the penetration depth of the first protrusion 31 according to the type of the drug, etc., the effect of the drug can be maximized. In addition, by adjusting the penetration depth of the second protrusion 32 according to the degree of the target blood flow promoting effect, the blood flow promoting effect can be effectively produced.

[0056] Furthermore, by making the first protrusion 31 and the second protrusion 32 penetrate the stratum corneum S11 as the surface layer of the skin S, or the layer S12 located inside the stratum corneum, so that the first protrusion 31 and the second protrusion 32 do not penetrate the dermis S2, which is the subcutaneous tissue U at a deeper part than the skin S, the pain associated with percutaneous absorption can be greatly reduced compared with the existing syringe. The skin S usually contains: the epidermis S1 including the stratum corneum S11 constituting the surface layer of the skin S; the dermis S2 located inside the epidermis S1; and the subcutaneous tissue (not shown) located inside the dermis S2. Typically, the layer S12 located inside the stratum corneum S11 in the epidermis S1 includes the granular layer, the spinous layer, and the basal layer in order from near to far from the stratum corneum S11, and the dermis S2 is located inside the basal layer.

[0057] When the percutaneous absorption of the drug is performed using a syringe provided with an injection needle without the puncture depth control unit 40, the injection needle will pass through the stratum corneum and pierce the site S12 located inside the stratum corneum, the dermis S2, and the subcutaneous tissue, so the person into whom the injection needle is inserted must endure the pain caused by the piercing of the injection needle. However, according to the injection needle 1A, the percutaneous absorption of the drug and the promotion of blood flow can be performed while reducing the pain felt by the person into whom the injection needle is inserted.

[0058] From the viewpoint of low-invasive percutaneous absorption and pain suppression, the puncture depth control unit 40 is preferably controlled in a manner that the front ends of the first protrusion 31 and the second protrusion 32 do not reach the dermis and subcutaneous tissue U, and more preferably can be controlled so as not to reach the site S12 located inside the stratum corneum. The penetration depth of the first protrusion 31 and the second protrusion 32 is consistent with the distance in the height direction Z between the front ends of the first protrusion 31 and the second protrusion 32 and the puncture depth control unit near them. Therefore, by appropriately adjusting the distance in the height direction Z, the above-mentioned effect can be achieved more reliably. "Low invasiveness" in the present invention refers to a state in which the stratum corneum and the site located inside the stratum corneum are injured when the injection needle is pressed against the skin, but the dermis and subcutaneous tissue are not injured.

[0059] The injection needle 1A of the present invention has a blood flow promoting effect through the second protrusion 32, and has a blood flow promoting effect and performs liquid injection through the first protrusion 31, so that the functions of the first protrusion 31 and the second protrusion 32 are different. Therefore, compared with the case where a plurality of liquid-injectable protrusions are provided in order to obtain the blood flow promoting effect, the amount of liquid injected can be efficiently suppressed. In particular, when liquid is transported from a storage portion of a drug to a plurality of liquid-injectable protrusions, the degree of penetration into the skin is likely to differ depending on each protrusion, and according to the injection needle 1A of the present invention, the drug can be uniformly injected, leakage can be prevented, and the depth of the subcutaneous area that can be injected can also be uniform. In addition, the range of liquid injection can also be suppressed to the effective minimum range. By using the second protrusion 32 as a guide / index for vertically piercing the injection needle 1A into the skin and by restricting the deformation of the skin by the second protrusion 32, it is also possible to make the first protrusion 31 easy to penetrate. Furthermore, for example, by disposing the second protrusions on the outer periphery of the injection needle 1A, when the injection needle 1A is inevitably inserted obliquely to the skin and not perpendicularly to the skin during use, the protrusions disposed on the outer periphery of the injection needle 1A may not sufficiently penetrate the skin depending on the direction, but the first protrusions disposed on the inner periphery of the injection needle 1A easily penetrate the skin sufficiently, and the drug can be injected into the skin S without leakage. That is, the injection needle 1A of the present invention can easily control the injection amount of the liquid and the range of the liquid injection, and can efficiently inject the drug.

[0060] From the viewpoint of significantly reducing the pain associated with percutaneous absorption or reliably injecting the drug from the first protrusion 31 into the skin S, the height difference between the tip position of the first protrusion 31 and the position of the puncture depth control part 40 is preferably 1 μm or more, and more preferably 5 μm or more. The height difference is the difference H1-H3 between the protrusion height H1 of the first protrusion 31 and the distance H3 from the surface of the sheet base 2 to the puncture depth control part 40.

[0061] Furthermore, from the viewpoint of not needlessly damaging the dermis, the difference H1 - H3 is preferably 5000 μm or less, and more preferably 4000 μm or less.

[0062] Furthermore, the difference H1 - H3 is preferably greater than or equal to 1 μm and less than or equal to 5000 μm, and more preferably greater than or equal to 5 μm and less than or equal to 4000 μm.

[0063] From the viewpoint of being able to significantly reduce the pain associated with the blood flow promoting effect of the second protrusion 32, inhibit the poor puncture of the second protrusion due to the elasticity of the skin, and allow the second protrusion to fully penetrate the skin, the protrusion height H2 of the second protrusion 32 is preferably greater than the distance H3 from the surface of the sheet base 2 to the puncture depth control part 40, that is, H2≥H3, and more preferably H2>H3.

[0064] From the same viewpoint, the difference H2 - H3 is preferably 0 or more, more preferably 100 μm or more, and further preferably 400 μm or more.

[0065] Furthermore, from the viewpoint of not excessively damaging the skin, the difference H2 - H3 is preferably 5000 μm or less, and more preferably 4000 μm or less.

[0066] Furthermore, the difference H2 - H3 is preferably 0 or more and 5000 μm or less, more preferably 100 μm or more and 5000 μm or less, and further preferably 400 μm or more and 4000 μm or less.

[0067] From the viewpoint of more reliably achieving the blood flow promoting effect and reliably puncturing the first protrusion 31 to suppress drug leakage caused by insufficient puncture, the first protrusion 31 is preferably higher than the second protrusion 32. More specifically, the difference H1-H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is preferably 1 μm or more, and more preferably 5 μm or more.

[0068] In addition, from the viewpoint of achieving both ease of liquid injection and blood flow promotion effect, the difference H1 - H2 is preferably 5000 μm or less, and more preferably 4000 μm or less.

[0069] Furthermore, the difference H1 - H2 is preferably greater than or equal to 1 μm and less than or equal to 5000 μm, and more preferably greater than or equal to 5 μm and less than or equal to 4000 μm.

[0070] From the viewpoint of suppressing obstruction of penetration due to deformation of the skin when the first protrusion 31 is pressed against the skin, improving puncture performance, and reliably injecting the drug into the skin S, the protrusion height H1 of the first protrusion 31 is preferably greater than 10 μm, and more preferably greater than 20 μm.

[0071] Furthermore, from the viewpoint of low invasion, the protrusion height H1 of the first projection 31 is preferably 5000 μm or less, and more preferably 4000 μm or less.

[0072] Furthermore, from the viewpoint of achieving both improved punctureability and low invasiveness, the protrusion height H1 of the first projection 31 is preferably 10 μm or more and 5000 μm or less, and more preferably 20 μm or more and 4000 μm or less.

[0073] From the viewpoint of stimulating the skin by pressing against the skin and promoting blood flow, the protrusion height H2 of the second protrusion 32 is preferably 10 μm or more, and more preferably 20 μm or more.

[0074] Furthermore, from the viewpoint of low invasion, the protrusion height H2 of the second protrusion 32 is preferably 5000 μm or less, and more preferably 4000 μm or less.

[0075] Furthermore, from the viewpoint of enhancing blood flow promotion, the protrusion height H2 of the second protrusion 32 is preferably 10 μm or more and 5000 μm or less, and more preferably 20 μm or more and 4000 μm or less.

[0076] The distance H3 from the surface of the sheet base 2 to the puncture depth control portion 40 is preferably 5 μm or more, and more preferably 10 μm or more.

[0077] Furthermore, from the viewpoint of improving the puncture property of the first projections 31 , the distance H3 is preferably 4000 μm or less, and more preferably 3000 μm or less.

[0078] Furthermore, the distance H3 is preferably not less than 5 μm and not more than 4000 μm, and more preferably not less than 10 μm and not more than 3000 μm.

[0079] In practice, the tip diameter of the first protrusion 31 is preferably 1 μm or more, and more preferably 5 μm or more.

[0080] Furthermore, from the viewpoint of suppressing the penetration resistance due to the elastic force of the skin, the tip diameter of the first projection 31 is preferably 300 μm or less, and more preferably 100 μm or less.

[0081] Furthermore, the tip diameter of the first projection 31 is preferably not less than 1 μm and not more than 300 μm, and more preferably not less than 5 μm and not more than 100 μm.

[0082] The tip diameter of the second protrusion 32 is preferably 1 μm or more, and more preferably 5 μm or more.

[0083] Furthermore, from the viewpoint of improving the blood flow promoting effect, the tip diameter of the second projection 32 is preferably 300 μm or less, and more preferably 200 μm or less.

[0084] Furthermore, the tip diameter of the second protrusion 32 is preferably 1 μm or more and 300 μm or less, and more preferably 5 μm or more and 200 μm or less.

[0085] From the viewpoint that the third protrusion 33 functions as a stopper to prevent the first protrusion 31 from excessively penetrating, the tip diameter of the third protrusion 33 is preferably 2 μm or more, and more preferably 10 μm or more.

[0086] The diameter of the tip of the second protrusion 32 may be larger than or smaller than the diameter of the tip of the first protrusion 31 .

[0087] Furthermore, from the viewpoint of increasing the density of the first projections, the second projections, and the like, the tip diameter of the third projections 33 is preferably 2000 μm or less, and more preferably 100 μm or less.

[0088] Furthermore, the tip diameter of the third projection 33 is preferably not less than 2 μm and not more than 2000 μm, and more preferably not less than 10 μm and not more than 100 μm.

[0089] The diameter of the distal end of the third protrusion 33 may be larger than or smaller than the diameter of the distal end of the first protrusion 31 .

[0090] The tip diameters of the first to third projections 31 to 33 are measured by the following method.

[0091] [Method for measuring the tip diameter of the protrusion in the injection needle]

[0092] Use a scanning electron microscope (SEM) or microscope such as Figure 4 The tip of the protrusion (the first protrusion 31, the second protrusion 32 or the third protrusion 33) of the measurement object is observed as shown. Figure 4 As shown in FIG. 1 , a virtual straight line ILa is extended along the straight line portion of one of the two side sides 1a and 1b, and a virtual straight line ILb is extended along the straight line portion of the other side side 1b. Then, on the front end side, the portion where one side 1a leaves the virtual straight line ILa is obtained and is taken as the first front end point 1a1, and the portion where the other side 1b leaves the virtual straight line ILb is obtained and is taken as the second front end point 1b1. The length L of the straight line connecting the first front end point 1a1 and the second front end point 1b1 obtained in this way is measured. The measured length of the straight line is taken as the front end diameter of the protrusion to be measured.

[0093] As described above, the first protrusion 31 preferably has an opening 31a at the front end. The opening 31a is preferably formed not at the front end of the first protrusion 31 but at the side of the first protrusion 31. When the opening 31a is formed at such a position, the opening 31a is not easy to collapse when the first protrusion 31 pierces the skin, and liquid such as a medicine can be stably supplied from the injection needle 1A to the inside of the skin through the opening 31a.

[0094] The first protrusion 31 can be arranged at any position in the protrusion arrangement area, but is preferably located at a position that is closer to the inside of the protrusion arrangement area than the second protrusion 32, that is, the center of the protrusion arrangement area. Thus, when the injection needle 1A is pressed against the skin, it is easy to apply a load to the first protrusion 31, and it is easy for the first protrusion 31 to pierce the skin. In addition, the first protrusion 31 is preferably surrounded by the second protrusion 32. Thus, the part pierced by the first protrusion 31 is surrounded by the immune induction area where blood flow is promoted due to the weak stimulation of the second protrusion 32, so that the efficacy of the drug injected through the first protrusion 31 can be improved. In addition, when the injection needle 1A is used, the injection needle 1A may inevitably be inserted obliquely to the skin instead of perpendicularly to the skin. In this case, by positioning the first protrusion 31 on the center of the image, the first protrusion 31 can be stably inserted into the skin regardless of the direction in which the injection needle 1A is inclined relative to the skin, and leakage of the drug when the insertion is insufficient can be effectively suppressed. From the viewpoint of more significantly achieving these effects, the second protrusions 32 are preferably located at the outermost position of the protrusion arrangement region.

[0095] The arrangement pattern of the first protrusions 31 , the second protrusions 32 , and the third protrusions 33 is not particularly limited.

[0096] From the viewpoint of correctly controlling the puncture depth, it is preferable to have an arrangement in which either or both of the first protrusion 31 and the second protrusion 32 are arranged between a pair of adjacent third protrusions 33 (hereinafter referred to as the "first arrangement"). It is also preferable to have an arrangement in which either or both of the first protrusion 31 and the second protrusion 32 without the puncture depth control portion are arranged between the composite protrusions (composite first protrusions 51 or composite second protrusions 52) having the puncture depth control portion (hereinafter referred to as the "second arrangement").

[0097] The protrusions located between the third protrusions 33 in the first arrangement, or the protrusions located between the compound protrusions in the second arrangement can be only the first protrusion 31, only the second protrusion 32, or both the first protrusion 31 and the second protrusion 32. The number of protrusions located between the third protrusions 33 or between the compound protrusions is preferably more than 1 and less than 4, and more preferably 1 or 2.

[0098] For example, in Figure 5 In the configuration patterns shown in (a), (b) and (e), as the first arrangement, there are the first arrangement arranged in the first direction X, the first arrangement arranged in the second direction Y, and the first arrangement arranged in a direction inclined relative to both the first direction X and the second direction Y, more specifically, in a direction inclined at an angle of 45 degrees. Figure 5In the arrangement patterns shown in (d) and (c), as the first arrangement, a plurality of protrusions as the first protrusions 31 or the second protrusions 32 are arranged between the third protrusions 33. Figure 8 (a) and Fig.11 In the arrangement pattern shown in (a), as the second arrangement, there is included a second arrangement arranged in the first direction X and a second arrangement arranged in the second direction Y. Figure 8 (c) and Fig.11 In the configuration pattern shown in (b), the second arrangement includes a second arrangement arranged in the first direction X, a second arrangement arranged in the second direction Y, and a second arrangement arranged in a direction inclined relative to the first direction X and the second direction Y, more specifically, in a direction inclined at an angle of 45 degrees.

[0099] The first array or the second array preferably exists in plurality in the protrusion arrangement region, and preferably exists in plurality in a dispersed state in the planar direction of the protrusion arrangement region.

[0100] From the viewpoint of correctly controlling the puncture depth, it is also preferable to have the following arrangement: an arrangement in which at least three or more third protrusions 33 are arranged so as to surround the first protrusion 31 or the second protrusion 32 (hereinafter referred to as the "third arrangement"), or an arrangement in which at least three or more protrusions serving as the second protrusion 32 or the third protrusion 33 are arranged so as to surround the first protrusion 31 (hereinafter referred to as the "fourth arrangement"). It is also preferable to have an arrangement in which at least three or more composite protrusions (composite first protrusions 51 or composite second protrusions 52) having a puncture depth control portion are arranged so as to surround the first protrusion 31 or the second protrusion 32 which does not have a puncture depth control portion (hereinafter referred to as the "fifth arrangement").

[0101] The protrusions surrounded by the third protrusions 33 in the third array or the protrusions surrounded by the composite protrusions in the fifth array may be only the first protrusions 31, only the second protrusions 32, or both the first protrusions 31 and the second protrusions 32. Regarding the third array or the fifth array, the number of protrusions surrounded by the third protrusions 33 or the composite protrusions is preferably 1 or more and 4 or less, more preferably 1 or 2. Regarding the fourth array, the number of first protrusions 31 surrounded by the second protrusions 32 or the third protrusions 33 is preferably 1 or more and 10 or less, more preferably 1 or more and 5 or less.

[0102] For example, Figure 5 The arrangement patterns shown in (a), (b), and (e) include a third array in which one of the first protrusions 31 or the second protrusions 32 is surrounded by the third protrusions 33 . Figure 5The arrangement patterns shown in (c) and (d) include a third array in which a plurality of protrusions, which are the first protrusions 31 or the second protrusions 32 , are surrounded by the third protrusions 33 .

[0103] The third array, the fourth array, or the fifth array preferably exists in plurality in the protrusion arrangement region, and preferably exists in plurality in a dispersed state in the planar direction of the protrusion arrangement region.

[0104] In the arrangement pattern of the first protrusion 31, the second protrusion 32 and the third protrusion 33, for example Figure 5 As shown in (a), a pair of second protrusions 32, 32 may be arranged in a manner that the first protrusion 31 is sandwiched between them in the first direction X and the second direction Y, and a third protrusion 33 may be arranged in a manner that the second protrusions 32 are sandwiched between them in the first direction X or the second direction Y. Figure 5 As shown in (b), the second protrusion 32 and the third protrusion 33 are arranged to surround the first protrusion 31, and the second protrusion 32 can be arranged at a position closer to the outside than the third protrusion 33. Figure 5 As shown in (c), the second protrusion 32 and the third protrusion 33 are arranged to surround the first protrusion 31, and the second protrusion 32 can be arranged at a position closer to the inside than the third protrusion 33. Figure 5 As shown in (d), the first protrusion 31 and the third protrusion 33 are arranged to surround the second protrusion 32, and the third protrusion 33 can be arranged at a position closer to the outside than the first protrusion 31. Figure 5 As shown in (e), the first protrusion 31 and the third protrusion 33 are arranged to surround the second protrusion 32, and the third protrusion 33 can be arranged at a position closer to the inside than the first protrusion 31. Figure 5 In (a) to (e) of FIG. 1 , the first protrusions 31 are indicated by hatching that is inclined upward to the right, the second protrusions 32 are indicated by hatching that is inclined downward to the right, and the third protrusions 33 are indicated by dotted hatching.

[0105] From the viewpoint of preventing the first protrusion from being difficult to penetrate due to interference from deformation of the skin when adjacent protrusions are pressed against the skin, the distance D between the front ends of adjacent protrusions when looking down at the sheet base 2 is preferably greater than 0.01 mm, more preferably greater than 0.02 mm, further preferably greater than 0.1 mm, and particularly preferably greater than 0.5 mm.

[0106] Furthermore, from the viewpoint of being able to obtain the blood flow improvement effect caused by adjacent protrusions without gaps in an appropriate range, the distance D is preferably 10 mm or less, more preferably 5 mm or less, and even more preferably 3 mm or less.

[0107] Furthermore, the distance D is preferably greater than or equal to 0.01 mm and less than or equal to 10 mm, more preferably greater than or equal to 0.1 mm and less than or equal to 5 mm, and even more preferably greater than 0.5 mm and less than or equal to 3 mm.

[0108] Adjacent protrusions refer to two protrusions with the shortest distance between their vertices. When a protrusion is surrounded by a plurality of other protrusions with the same distance between the protrusions, it refers to the protrusion and the other protrusions. The distance D is measured by taking only the first protrusion 31 and the second protrusion 32 as protrusions constituting adjacent protrusions. That is, even if there is a third protrusion 33 whose front end surface is the puncture depth control portion 40, the distance D is measured without taking into account the third protrusion 33.

[0109] The thickness T of the sheet base 2 of the injection needle 1A is preferably 5 μm or more, more preferably 10 μm or more, and further preferably 20 μm or more.

[0110] Furthermore, from the viewpoint of easily pressing the injection needle 1A against the skin, the thickness T is preferably 2000 μm or less, more preferably 1000 μm or less, and even more preferably 500 μm or less.

[0111] The thickness T is preferably 5 μm or more and 2000 μm or less, more preferably 10 μm or more and 1000 μm or less, and further preferably 20 μm or more and 500 μm or less (see Figure 1 ).

[0112] The thickness T of the sheet base 2 can be measured by the following method.

[0113] <Method for measuring the thickness of the sheet base>

[0114] Use SEM or microscope, such as Figure 1 As shown in FIG. 1 , the sheet base 2 of the injection needle 1A is observed at a predetermined magnification. Figure 1 As shown, the distance from the surface of the sheet base 2 where the protrusions protrude to the surface opposite to the surface is measured along the thickness direction Z of the sheet base 2. The distance measured in this way is defined as the thickness T of the base.

[0115] The injection needle 1A may include only the first protrusion 31 , but preferably includes a plurality of first protrusions 31 .

[0116] Furthermore, the injection needle 1A preferably has a width of 1 cm 2 The number N1 of the first protrusions 31 or the number N2 of the second protrusions becomes a region as described below.

[0117] From the viewpoint of being able to efficiently inject liquid, the number N1 of the first projections 31 or the number N2 of the second projections is preferably one or more, more preferably five or more, and even more preferably ten or more.

[0118] Furthermore, from the viewpoint of being able to easily control the injection amount and the range of liquid injection, the number N1 of the first protrusions 31 or the number N2 of the second protrusions is preferably 400 or less, more preferably 300 or less, and even more preferably 200 or less.

[0119] Furthermore, from the viewpoint of achieving both the above, the number N1 of the first protrusions 31 or the number N2 of the second protrusions is preferably 1 or more and 400 or less, more preferably 5 or more and 300 or less, and even more preferably 10 or more and 200 or less.

[0120] The injection needle 1A may have only one second protrusion or may have a plurality of second protrusions, but preferably has a plurality of first protrusions 31 .

[0121] The injection needle 1A preferably has a width of 1 cm 2 The total number N1+N2 of the first protrusions 31 and the second protrusions 32 is a region as described below.

[0122] From the viewpoint of easily achieving a blood flow promoting effect by producing a flushing reaction in the entire range where the injection needle 1A is applied, and from the viewpoint of being able to efficiently inject liquid, the total number N1+N2 is preferably 2 or more, more preferably 5 or more, further preferably 10 or more, particularly preferably 20 or more, and especially preferably 30 or more.

[0123] From the viewpoint of being able to easily control the injection amount and liquid injection range of the liquid, the total number N1+N2 is preferably 500 or less, more preferably 300 or less, further preferably 200 or less, and particularly preferably less than 200.

[0124] From the viewpoint of taking both into account, the total number N1+N2 is preferably 10 or more and 500 or less, more preferably 20 or more and 300 or less, and even more preferably 30 or more and less than 200 or less.

[0125] From the viewpoint of effectively generating a flushing reaction around the first protrusion 31 where the liquid is injected to obtain a blood flow promoting effect, and from the viewpoint of preventing the first protrusion 31 from not piercing the skin when the injection needle 1A is pressed against the skin and improving the liquid injection rate by making the first protrusion 31 pierce reliably, the injection needle 1A is 1 cm thick. 2 The ratio N2 / N1 of the number N2 of the second protrusions to the number N1 of the first protrusions 31 is preferably 0.01 or more, more preferably 0.1 or more, further preferably 0.5 or more, particularly preferably 1 or more, and particularly preferably 2.4 or more.

[0126] From the viewpoint of being able to puncture with a smaller puncture pressure and to efficiently inject the liquid by reducing the amount of liquid injected per first projection, the ratio N2 / N1 is preferably 100 or less, more preferably 50 or less, and even more preferably 10 or less.

[0127] From the viewpoint of taking both into consideration, the ratio N2 / N1 is preferably 0.01 or more and 100 or less, more preferably 1 or more and 50 or less, and further preferably 2.4 or more and 10 or less.

[0128] Every 1 cm when looking down at injection needle 1A 2 The number of the first projections 31 can be measured by the following method.

[0129] < per 1cm 2 Method for measuring the number of first protrusions>

[0130] Every 1cm 2 The number of the first projections 31 can be calculated by dividing the number of the first projections 31 included in the projection arrangement region in which the plurality of fine projections 3 are arranged in a dispersed state in the planar direction by the total area (cm 2 ). The total area of ​​the protrusion arrangement region is the area of ​​the region surrounded by a virtual line connecting the vertices of the protrusions arranged at the outer edge of the region when the injection needle 1A is viewed from above. When the number of protrusions of the injection needle 1A is 2 or less, it can be measured by counting the number of first protrusions 31 contained in a 1 cm square region when the injection needle 1A is viewed from above.

[0131] By using the injection needle of the present invention, the blood flow promotion effect can be obtained in a wide range where the first protrusions and the second protrusions are arranged, and the drug can be reliably injected into the skin.

[0132] The inventors of the present invention have found that by injecting the drug into the skin, the blood flow around the injected drug is improved, the drug is easily absorbed by the skin, the outflow of the unabsorbed drug to the outside of the skin can be suppressed, and the effect of the drug is easily obtained.

[0133] Next, other embodiments of the injection needle of the present invention will be described. For these embodiments, only the differences from the above embodiment will be described, and the description of the above embodiment can be appropriately applied to the points not specifically described, and the same reference numerals are given to the same components. Figure 6 to Figure 8 and Figures 9 to 11 These embodiments are shown.

[0134] The injection needle of the present invention preferably includes a composite first protrusion 51 in which a third protrusion and a puncture depth control portion 40 are integrally formed in the sheet base direction of the first protrusion 31. An example of an injection needle (hereinafter also referred to as "injection needle 1B") including a composite first protrusion 51 is described. In the injection needle 1B, the first protrusion 31 is integrally formed with a puncture depth control portion 40 at the outer peripheral portion of the base side portion. In more detail, an expanded diameter portion 41 is formed at the base side portion, and a step portion extending radially outward from the first protrusion 31 is formed at the upper end portion of the expanded diameter portion 41. The step portion serves as the puncture depth control portion 40.

[0135] From the viewpoint of functioning as a stopper that prevents the first projection 31 from excessively penetrating, the protruding length L1 of the step portion of the composite first projection 51 is preferably 0.002 mm or more, and more preferably 0.01 mm or more.

[0136] Furthermore, from the viewpoint of increasing the density of the first protrusions 31 and the second protrusions 32 and obtaining a blood flow promoting effect in a wide range of application of the fine protrusion tool, the length L1 is preferably 2 mm or less, and more preferably 0.1 mm or less.

[0137] Furthermore, the length L1 is preferably not less than 0.002 mm and not more than 2 mm, and more preferably not less than 0.01 mm and not more than 0.1 mm.

[0138] The length L1 is a straight-line distance obtained by measuring the distance between the inner end and the outer end of the step portion along a plane perpendicular to the height direction. Figure 6 As shown, it is the distance between two tangent points of the inner end and the outer end with tangent lines P1 and P2 that form an angle of 45 degrees with respect to the center line CL of the first protrusion.

[0139] In the injection needle 1B, when the composite first protrusion 51 and the second protrusion 32 are inserted into the skin from the front end side, the insertion of the composite first protrusion 51 and the second protrusion 32 can be stopped by the contact of the puncture depth control unit 40 with the surface of the skin, thereby preventing the composite first protrusion 51 and the second protrusion 32 from puncturing deeper into the skin. In the composite first protrusion 51, the puncture depth control unit 40 is integrally formed around the first protrusion 31, so that the composite first protrusion 51 can be more reliably prevented from puncturing deeper into the skin. Figure 7 .

[0140] The arrangement pattern of the composite primary protrusions 51 and secondary protrusions 32 is not particularly limited. Figure 8 As shown in (a), a pair of second protrusions 32, 32 are arranged in a manner of sandwiching the composite first protrusion 51 in the first direction X and the second direction Y. Figure 8As shown in (b), the second protrusion 32 is arranged so as to surround the composite first protrusion 51. Figure 8 As shown in (c), the composite first protrusion 51 is arranged so as to surround the second protrusion 32. Figure 8 In (a) and (b), the composite first protrusion 51 is represented by the upper right slanting hatching, and the second protrusion 32 is represented by the lower right slanting hatching.

[0141] The injection needle of the present invention preferably includes a composite second protrusion 52 in which a puncture depth control portion 40 is integrally formed around the second protrusion 32. An example of an injection needle having a composite second protrusion 52 (hereinafter also referred to as "injection needle 1C") is described. In the injection needle 1C, the second protrusion 32 is integrally formed with a puncture depth control portion 40 on the outer peripheral portion of the base side portion. In more detail, an expanded diameter portion 41 is formed on the base side portion, and a step portion extending radially outward from the second protrusion 32 is formed at the upper end portion of the expanded diameter portion 41. The step portion becomes the puncture depth control portion 40. The example is shown in Fig. 9 .

[0142] From the viewpoint of functioning as a stopper that prevents the second protrusion 32 from excessively penetrating, the protruding length L2 of the step portion of the composite second protrusion 52 is preferably 0.002 mm or more, and more preferably 0.01 mm or more.

[0143] Furthermore, from the viewpoint of increasing the density of the first protrusions 31 and the second protrusions 32 and obtaining a blood flow promoting effect in a wide range of application of the injection needle, the length L2 is preferably 2 mm or less, and more preferably 0.1 mm or less.

[0144] Furthermore, the length L2 is preferably greater than or equal to 0.002 mm and less than or equal to 2 mm, and more preferably greater than or equal to 0.01 mm and less than or equal to 0.1 mm.

[0145] The length L2 can be measured in the same manner as the length L1.

[0146] In the injection needle 1C, when the first protrusion 31 and the composite second protrusion 52 are inserted into the skin from the front end side, the insertion of the first protrusion 31 and the composite second protrusion 52 can be stopped by the contact of the puncture depth control unit 40 with the surface of the skin, thereby preventing the first protrusion 31 and the composite second protrusion 52 from puncturing deeper into the skin. In the composite second protrusion 52, the puncture depth control unit 40 is integrally formed around the second protrusion 32, so that the composite second protrusion 52 can be more reliably prevented from puncturing deeper into the skin. Fig.10 .

[0147] The arrangement pattern of the first protrusions 31 and the composite second protrusions 52 is not particularly limited. Fig.11 As shown in (a), a pair of composite second protrusions 52, 52 are arranged in a manner that the first protrusion 31 is sandwiched in the first direction X and the second direction Y. In addition, it is also possible to Fig.11 As shown in (b), the composite second protrusion 52 is arranged so as to surround the first protrusion 31. Fig.11 As shown in (c), the first protrusion 31 is arranged so as to surround the composite second protrusion 52. Fig. 9 In (a) and (b), the first protrusion 31 is represented by the upper right slanting hatching, and the compound second protrusion 52 is represented by the lower right slanting hatching.

[0148] Next, matters common to the above-mentioned embodiments will be described.

[0149] The injection needles 1A, 1B, and 1C of the above-mentioned embodiments preferably contain a thermoplastic resin from the viewpoints of material handling properties, strength and processability of the injection needle, ensuring hardness of the first protrusion 31 and the second protrusion 32, facilitating injection of liquid, and improving the blood flow promotion effect. The injection needle is more preferably formed of a base sheet containing a thermoplastic resin.

[0150] The base sheet preferably contains a thermoplastic resin as a main constituent material. The main constituent material means that 50% or more of the total mass of the base sheet of the fine projection device is the mass of the thermoplastic resin, and more preferably the mass of the thermoplastic resin is 100%.

[0151] Examples of the thermoplastic resin include polyolefin, polyester, polyamide, polyamideimide, polyetheretherketone, polyetherimide, polyvinyl chloride, acrylic resin, polystyrene resin, and combinations thereof.

[0152] Examples of the polyolefin include polypropylene and polyethylene.

[0153] Examples of the polyester include polyethylene terephthalate, polyfatty acid esters, polylactic acid, polycaprolactone, and polybutylene succinate.

[0154] Examples of polyamide include nylon and the like.

[0155] From the viewpoint of biodegradability, poly fatty acid esters are preferably used. Specific examples of poly fatty acid esters include polylactic acid, polyglycolic acid, and combinations thereof.

[0156] From the viewpoint of improving the moldability and dimensional stability of the injection needle, the mass of the thermoplastic resin contained in the injection needles 1A, 1B is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more relative to the total mass of the injection needles 1A, 1B, 1C.

[0157] Furthermore, from the viewpoint of adding, for example, a functional agent to the injection needle to impart various effects, the mass ratio of the thermoplastic resin is preferably 100% or less, more preferably 98% or less, and even more preferably 96% or less.

[0158] The mass ratio of the thermoplastic resin is preferably 50% to 100%, more preferably 70% to 98%, and even more preferably 90% to 96%.

[0159] Here, as various functional agents, antimicrobial agents, bactericides, moisturizers, flow improvers, antistatic agents, colorants, etc. can be used.

[0160] Although the present invention has been described based on the preferred embodiments thereof, the present invention is not limited to the above-described embodiments and can be modified as appropriate.

[0161] For example, in the first embodiment, the second protrusion 32 and the third protrusion 33 are solid, but the second protrusion 32 and the third protrusion 33 may be hollow. In addition, in the second embodiment, the composite second protrusion 52 is solid, but the composite second protrusion 52 may be hollow. In the injection needles 1A, 1B, and 1C, the protrusions other than the first protrusion 31 are preferably solid. By adopting this method, it is possible to prevent the liquid to be discharged from the opening 31a of the first protrusion 31 from being stored inside other protrusions, so that the liquid can be injected efficiently.

[0162] In addition, in injection needles 1A~1C, the protrusions are arranged in an array (single or multiple columns). In addition to the array, any arbitrary configuration may be adopted, such as a configuration in which multiple protrusions are arranged in an arbitrary annular shape such as a circle, oval, square, rectangle, hexagon, star, etc.

[0163] In addition, in the injection needle 1A, the third protrusion 33 is cylindrical, but the third protrusion 33 may also be a truncated cone with a flat front end, or a conical shape with a curved front end surface. In addition, the top view shape of the third protrusion 33 is not particularly limited, and may also be circular, elliptical, square, rectangular, hexagonal, star-shaped, etc.

[0164] In addition, the injection needle of the present invention may have a first protrusion 31, a second protrusion 32, a composite first protrusion 51 and a composite second protrusion 52, or may have a first protrusion 31, a second protrusion 32 and a composite first protrusion 51, or may have a first protrusion 31, a second protrusion 32 and a composite second protrusion 52, or may have a first protrusion 31, a composite first protrusion 51 and a composite second protrusion 52, or may have a composite first protrusion 51 and a composite second protrusion 52.

[0165] In addition, the composite first protrusion 51 can be Fig.12As shown in (a), the puncture depth control part 40 is formed integrally around the plurality of first protrusions 31. In addition, the composite second protrusion 52 may be formed as follows. Fig.12 As shown in FIG. 2 ( a ), a puncture depth control portion 40 is integrally formed around the plurality of second protrusions 32 .

[0166] In addition, the second protrusion 32 may be Fig.12 As shown in (b), the cross-sectional shape is a portion of a circle.

[0167] Furthermore, the injection needle of the present invention may have one first protrusion 31 and one second protrusion 32 , respectively, or may have a plurality of them.

[0168] Example

[0169] Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

[0170] [Example 1]

[0171] Manufacturing and Figure 1 The injection needle 1A shown has the same structure and features as Figure 5 (a) The same configuration of the injection needle. The size of each protrusion of the injection needle, the size of the base of the sheet, and the size of each 1 cm 2 The number of the first protrusions and the distance between the tips of adjacent first protrusions or second protrusions are shown in Table 1. The injection needle was formed by subjecting a substrate sheet composed of 100% polylactic acid as a thermoplastic resin to protrusion forming processing using a processing needle to which ultrasonic vibration was applied.

[0172] [Example 2]

[0173] Manufacturing and Figure 1 The injection needle 1A shown has the same structure and Figure 5 (d) An injection needle having the same configuration as in Example 1 except that the elements are as shown in Table 1.

[0174] [Example 3]

[0175] Manufacturing and Fig. 9 The injection needle 1C shown has the same structure and Fig.11 (a) An injection needle having the same configuration as in Example 1 except that the elements are as shown in Table 1.

[0176] [Example 4]

[0177] Manufacturing and Figure 6 The injection needle 1B shown has the same structure and Figure 8 (a) An injection needle having the same configuration as in Example 1 except that the elements are as shown in Table 1.

[0178] [Example 5]

[0179] Manufacturing and Figure 1 The injection needle 1A shown has the same structure and Figure 5 (f) An injection needle having the same configuration. The same as in Example 1 except that the elements are as shown in Table 1.

[0180] [Example 6]

[0181] Manufacturing and Figure 1 The injection needle 1A shown has the same structure and Fig.14 (a) An injection needle having the same configuration as in Example 1 except that the elements are as shown in Table 1.

[0182] [Example 7]

[0183] Manufacturing and Figure 1 The injection needle 1A shown has the same structure and Fig.14 (b) An injection needle having the same configuration. The same as in Example 1 except that the elements are as shown in Table 1.

[0184] [Comparative Example 1]

[0185] Manufacturing an injection needle having the first protrusion 31 and the third protrusion 33 (refer to Fig.13 (a) and (b)). In addition to making the elements as shown in Table 1 and placing the protrusions 31 and 33 Fig.13 Except for the configuration shown in (b), it is the same as Example 1.

[0186] [Evaluation of flushing reaction]

[0187] The injection needles of Examples 1 to 7 and Comparative Example 1 were evaluated for flushing reaction by the following method.

[0188] The injection needles of Examples 1 to 7 and Comparative Example 1 were attached to the skin of the test subject and pressed for 10 seconds with a load of about 5 N. After pressing for 10 seconds, the fine protrusion device was peeled off, and the site where the fine protrusion device was pressed was observed under a microscope at a magnification of 30 times, and the range of the flushing reaction was evaluated according to the following criteria. The evaluation results are shown in Table 1.

[0189] A: The exclusive area of ​​flushing reaction is more than 70%

[0190] B: The flushing reaction area is more than 30% and less than 70%

[0191] C: The exclusive area of ​​flushing reaction is more than 10% and less than 30%

[0192] D: The flushing reaction exclusive area is 0% or more and less than 10%

[0193] The flushing reaction-specific area was calculated using the following formula.

[0194] Blush reaction specific area (%) = area where blush reaction occurred / area of ​​protrusion arrangement region × 100

[0195] The area of ​​the protrusion arrangement region is an area surrounded by the protrusions 31 , 32 , and 33 arranged on the outermost sides included in the region.

[0196] [Evaluation of injectability of drugs]

[0197] The injectability of the drug was evaluated for the injection needles of Examples 1 to 7 and Comparative Example 1 by the following method.

[0198] The injection needles of Examples 1 to 7 and Comparative Example 1 were respectively mounted on a syringe (manufactured by Hamilton Company, GASTIGHT #1710), and the excised pigskin was pierced with a load of 2N or more with a reaction force at an angle of 10° from the vertical, and 100 μL of the drug solution was injected at an injection rate of 1 μL / sec. After the injection, the syringe was pulled out of the pigskin, and the drug that did not enter the pigskin and overflowed or leaked was wiped off with a rag. The weight of the excised pigskin before and after the injection of the drug solution was measured, and the difference in weight from the pigskin before the injection of the drug solution was taken as the injection amount of the drug solution, and the injection amount / dose × 100 was taken as the injection ratio (%), and evaluated according to the following standards. In addition, regarding the puncture depth of the injection needle, it was confirmed that the puncture of the first protrusion could be suppressed by the puncture depth control unit.

[0199] Table 1 shows the evaluation results.

[0200] A: Injection ratio 75% or more and 100% or less

[0201] B: Injection ratio 50% or more and less than 75%

[0202] C: Injection ratio 25% or more and less than 50%

[0203] D: Injection ratio 0% or more and less than 25%

[0204] [Table 1]

[0205]

[0206] As shown in Table 1, the injection needle of Comparative Example 1 was evaluated as B for flushing reaction, but the evaluation of injectability of the drug was D. That is, it can be seen that the injection needle of Comparative Example 1 can obtain the blood flow promotion effect, but it is difficult to inject liquid. In addition, regarding the injection needle of Comparative Example 1, in the evaluation of injectability of the drug, sometimes the injection needle is not inserted enough, and most of the drug leaks from the opening (drug solution injection part) where the insertion is insufficient, making injection difficult.

[0207] Compared with the injection needle of Comparative Example 1, the injection needles of Examples 1 to 7 were evaluated as A, B, or C for flushing reaction and A or B for drug injectability. That is, it is known that the injection needles of Examples 1 to 7 can easily inject liquid and can obtain a blood flow promoting effect.

[0208] Industrial Application Possibility

[0209] The injection needle of the present invention can control the depth of piercing the skin, can inject liquid, and can effectively promote blood flow.

Claims

1. An injection needle, characterized in that: having a protrusion protruding from the base of the sheet, The protrusions include: a first protrusion having an opening at a front end and being hollow; and a second protrusion having no opening at a front end, A puncture depth control portion is provided at an intermediate position, the intermediate position being a position lower than the tip of the first protrusion and higher than the surface of the sheet base. The puncture depth control portion is located at a position lower than the front end of the second protrusion. The puncture depth control unit is a limiter for limiting the puncture depth of the first protrusion and the second protrusion.

2. An injection needle, characterized in that: having a protrusion protruding from the base of the sheet, The protrusions include: a first protrusion having an opening at a front end and being hollow; and a second protrusion having no opening at a front end, A puncture depth control portion is provided at an intermediate position, the intermediate position being a position lower than the tip of the first protrusion and higher than the surface of the sheet base. The protrusion protruding from the sheet base includes a third protrusion arranged around the first protrusion or the second protrusion, and the front end surface of the third protrusion serves as the puncture depth control portion. The puncture depth control unit is a limiter for limiting the puncture depth of the first protrusion and the second protrusion.

3. An injection needle, characterized in that: having a protrusion protruding from the base of the sheet, The protrusions include: a first protrusion having an opening at a front end and being hollow; and a second protrusion having no opening at a front end, A puncture depth control portion is provided at an intermediate position, the intermediate position being a position lower than the tip of the first protrusion and higher than the surface of the sheet base. The composite second protrusion includes the puncture depth control portion integrally formed around the second protrusion.

4. The injection needle according to any one of claims 1 to 3, characterized in that: The height difference between the tip position of the first projection and the position of the puncture depth control portion is 1 μm or more and 5000 μm or less.

5. The injection needle according to any one of claims 1 to 3, characterized in that: The height difference between the tip position of the first projection and the position of the puncture depth control portion is 5 μm or more.

6. The injection needle according to any one of claims 1 to 3, characterized in that: The height difference between the tip position of the first projection and the position of the puncture depth control portion is 4000 μm or less.

7. The injection needle according to any one of claims 1 to 3, characterized in that: The height of the first protrusion is higher than the height of the second protrusion.

8. The injection needle according to any one of claims 1 to 3, characterized in that: The composite first protrusion includes the puncture depth control portion integrally formed around the first protrusion.

9. The injection needle according to any one of claims 1 to 3, characterized in that: The composite second protrusion includes the puncture depth control portion integrally formed around the second protrusion.

10. The injection needle according to any one of claims 1 to 3, characterized in that: The protrusion protruding from the sheet base includes a third protrusion disposed around the first protrusion or the second protrusion, and the front end surface of the third protrusion serves as the puncture depth control portion.

11. The injection needle according to any one of claims 1 to 3, characterized in that: When the sheet base is viewed in plan, a distance between the tips of adjacent protrusions is greater than or equal to 0.01 mm and less than or equal to 10 mm.

12. The injection needle according to any one of claims 1 to 3, characterized in that: When the sheet base is viewed in plan, the distance between the tips of adjacent protrusions is 0.1 mm or more.

13. The injection needle according to any one of claims 1 to 3, characterized in that: When the sheet base is viewed from above, the distance between the tips of adjacent protrusions is 5 mm or less.

14. The injection needle according to any one of claims 1 to 3, characterized in that: The protrusions other than the first protrusion are solid.

15. The injection needle according to any one of claims 1 to 3, characterized in that: The injection needle contains a thermoplastic resin.

16. The injection needle according to any one of claims 1 to 3, characterized in that: The mass ratio of the thermoplastic resin contained in the injection needle relative to the total mass of the injection needle is 50% or more and 100% or less.

17. The injection needle according to any one of claims 1 to 3, characterized in that: The opening is not formed at the front end of the first protrusion but is formed at the side surface of the first protrusion.

18. The injection needle according to any one of claims 1 to 3, characterized in that: A difference H1 − H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is greater than or equal to 1 μm and less than or equal to 5000 μm.

19. The injection needle according to any one of claims 1 to 3, characterized in that: A difference H1 − H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is 5 μm or more.

20. The injection needle according to any one of claims 1 to 3, characterized in that: A difference H1 − H2 between the protrusion height H1 of the first protrusion 31 and the protrusion height H2 of the second protrusion 32 is 4000 μm or less.

21. The injection needle according to any one of claims 1 to 3, characterized in that: The tip diameter of the primary projection is not less than 1 μm and not more than 300 μm.

22. The injection needle according to any one of claims 1 to 3, characterized in that: The tip diameter of the primary projection is 5 μm or more.

23. The injection needle according to any one of claims 1 to 3, characterized in that: The tip diameter of the primary projection is 50 μm or less.

24. The injection needle according to any one of claims 1 to 3, characterized in that: The diameter of the front end of the second projection is larger than the diameter of the front end of the first projection.

25. The injection needle according to any one of claims 1 to 3, characterized in that: The protrusion height of the primary projection is not less than 10 μm and not more than 5000 μm.

26. The injection needle according to any one of claims 1 to 3, characterized in that: The protrusion height of the primary projections is 20 μm or more.

27. The injection needle according to any one of claims 1 to 3, characterized in that: The protrusion height of the primary projections is 4000 μm or less.

28. The injection needle according to any one of claims 1 to 3, characterized in that: The distance from the surface of the sheet base to the puncture depth control portion is 5 μm or more and 4000 μm or less.

29. The injection needle according to any one of claims 1 to 3, characterized in that: The distance from the surface of the sheet base to the puncture depth control portion is 10 μm or more.

30. The injection needle according to any one of claims 1 to 3, characterized in that: The distance from the surface of the sheet base to the puncture depth control portion is 3000 μm or less.

31. The injection needle according to any one of claims 1 to 3, characterized in that: Each of the plurality of first protrusions and the plurality of second protrusions is provided.

32. The injection needle according to any one of claims 1 to 3, characterized in that: A pair of second protrusions is arranged so as to sandwich the first protrusion.

33. The injection needle according to any one of claims 1 to 3, characterized in that: When looking down, every 1cm 2 A region in which the total number of the primary projections and the secondary projections is 10 or more and 500 or less.

34. The injection needle according to any one of claims 1 to 3, characterized in that: When looking down, every 1cm 2 A region in which the total number of primary projections and secondary projections is 20 or more.

35. The injection needle according to any one of claims 1 to 3, characterized in that: When looking down, every 1cm 2 An area where the total number of the first protrusions and the second protrusions is 300 or less.

36. The injection needle according to any one of claims 1 to 3, characterized in that: Every 1cm 2 A ratio N2 / N1 of the number N2 of the second protrusions to the number N1 of the first protrusions 31 is greater than or equal to 0.01 and less than or equal to 100.

37. The injection needle according to any one of claims 1 to 3, characterized in that: Every 1cm 2 A ratio N2 / N1 of the number N2 of the second protrusions to the number N1 of the first protrusions 31 is 1 or more.

38. The injection needle according to any one of claims 1 to 3, characterized in that: Every 1cm 2 The ratio N2 / N1 of the number N2 of the second protrusions to the number N1 of the first protrusions 31 is 50 or less.

39. The injection needle according to any one of claims 1 to 3, characterized in that: The plurality of second protrusions are arranged so as to surround the first protrusions, and the plurality of third protrusions are arranged so as to surround the plurality of second protrusions, and the front end surfaces of the plurality of third protrusions serve as the puncture depth control portion.

40. The injection needle according to any one of claims 1 to 3, characterized in that: A liquid medicine is stored in the hollow portion of the first projection.

41. An injection device, characterized in that: include: The injection needle according to any one of claims 1 to 3; and a medicine feeder capable of feeding the medicine to the first protrusion of the injection needle.

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