Microneedle injection device

Abstract

The utility model provides a microneedle injection device. The microneedle injection device comprises an injection assembly and a mold assembly, the injection assembly comprises an injection rod and a syringe, and the syringe is provided with an injection outlet; the injection rod is movably arranged on the syringe along the axial direction of the syringe; the mold assembly is provided with an injection port and an inner cavity communicated with the injection port, and the inner cavity is used for containing a microneedle mold; the mold assembly is connected with the injection cylinder in an abutting mode, and the injection opening is communicated with the injection outlet. The injection rod and the mold assembly are configured to apply pressure relative to each other. By means of the configuration, the forming liquid can be injected into the microneedle mold in the mold assembly in an injection mode, and the microneedle mold is arranged in the mold assembly and can be supported by the mold assembly. Furthermore, based on relative pressure application of the injection rod and the mold assembly, the pressure maintaining function can be achieved, the density and mechanical strength of the prepared microneedle are improved, and the appearance of the needle tip of the prepared microneedle is better.

Description

Technical Field

[0001] The utility model relates to the technical field of medical equipment, in particular to a micro-needle injection device. Background Art

[0002] Microneedles are a new type of minimally invasive drug delivery tool that can pierce the epidermal stratum corneum to create micro-nano channels that facilitate the entry of drugs into the dermis and subcutaneous tissue, and then be absorbed through capillaries. Microneedles need to be able to penetrate the skin, so the needle body of the microneedle must have good mechanical strength, and the higher the precision of the microneedle tip size, the better.

[0003] Polymer microneedles have the advantages of low production cost, high needle tip precision and high needle body strength. In the prior art, polymer microneedles are often prepared by hot pressing or soluble material casting, among which the polymer microneedles prepared by the soluble material casting method have low strength. However, the material filling degree of the hot pressing method is not good, and the molding of the microneedle is mainly driven by the pressure difference. When the depth and width of the microneedle are relatively large, the needle tip molding is difficult to ensure. In addition, the hot pressing method easily makes the microneedle density insufficient, resulting in poor mechanical strength of the microneedle. Utility Model Content

[0004] The utility model aims to provide a microneedle injection device to solve the problems of poor needle tip shape and poor microneedle strength of existing microneedle molding.

[0005] In order to solve the above technical problems, the utility model provides a microneedle injection device, which includes: an injection component and a mold component;

[0006] The injection assembly comprises an injection rod and an injection cylinder, wherein the injection cylinder has an injection outlet; the injection rod is movably disposed on the injection cylinder along the axial direction of the injection cylinder;

[0007] The mold assembly has an injection port and an inner cavity connected to the injection port, and the inner cavity is used to accommodate the microneedle mold; the mold assembly is abutted against the injection barrel, and the injection port is connected to the injection outlet;

[0008] The injection rod and the mold assembly are configured to be pressed against each other.

[0009] Optionally, the mold assembly includes a separable upper template and a lower template, the injection port is opened in the upper template, and the upper template and the lower template are assembled and connected to enclose the inner cavity.

[0010] Optionally, the mold assembly includes a guide member, which is disposed in the inner cavity and intersects with the extension direction of the injection port; the inner cavity forms a molding cavity under the partition of the guide member; the guide member is used to change the flow direction of the molding liquid flowing in from the injection port;

[0011] Optionally, the guide member has a flow groove arranged at an angle to the injection port, the guide member is connected to the upper template and covers the injection port, one end of the flow groove is connected to the injection port, and the other end of the flow groove is connected to the molding cavity.

[0012] Optionally, the flow channel includes a narrow section and an expansion section, the narrow section is located at an end of the flow channel communicating with the injection port; the expansion section is located at an end of the flow channel communicating with the molding cavity.

[0013] Optionally, the lower template has a mold receiving groove that is adapted to the shape of the microneedle mold, and the mold receiving groove constitutes a part of the inner cavity after the lower template is assembled and connected with the upper template.

[0014] Optionally, the microneedle injection device further comprises a lower template fixing assembly, wherein the lower template fixing assembly is detachably connected to the lower template to define a position of the lower template.

[0015] Optionally, the lower template fixing assembly includes a first fixing member and a second fixing member that are snap-fitted to each other. After the first fixing member and the second fixing member are snap-fitted to each other and assembled, a limiting cavity that is adapted to the contour shape of the lower template is formed. The lower template is accommodated in the limiting cavity and abuts against the cavity wall of the limiting cavity.

[0016] Optionally, the microneedle injection device further comprises a hot press, which comprises a pressing component and a heating base, the injection rod is connected to the pressing component, and the mold assembly is placed on the heating base; the pressing component is configured to apply pressure in the direction of the heating base.

[0017] Optionally, the microneedle injection device further includes the microneedle mold.

[0018] In summary, the microneedle injection device provided by the utility model includes an injection assembly and a mold assembly; the injection assembly includes an injection rod and a syringe, the syringe has an injection outlet; the injection rod is movably arranged on the syringe along the axial direction of the syringe; the mold assembly has an injection port and an inner cavity connected to the injection port, and the inner cavity is used to accommodate a microneedle mold; the mold assembly is abutted against the syringe, and the injection port is connected to the injection outlet; the injection rod and the mold assembly are configured to apply relative pressure.

[0019] With such configuration, the microneedle injection device provided by the utility model can be used on a hot press. The setting of the injection assembly can inject the molding liquid (such as a polymer material after high-temperature heat melting) into the microneedle mold in the mold assembly by injection, and the microneedle mold is placed in the mold assembly and can be supported by the mold assembly. Further, based on the relative pressure between the injection rod and the mold assembly, the pressure-maintaining function can be achieved to improve the density and mechanical strength of the prepared microneedles. It is especially suitable for silicone molds and microneedles with a large width-to-depth ratio, and the needle tip shape of the prepared microneedles is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Those skilled in the art will appreciate that the drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0021] Figure 1 is a schematic diagram of a microneedle injection device according to an embodiment of the utility model;

[0022] Figure 2 is a schematic diagram of an injection assembly of an embodiment of the utility model;

[0023] Figure 3 It is a schematic diagram of an upper template of an embodiment of the utility model;

[0024] Figure 4 is a schematic diagram of a flow guide member of an embodiment of the utility model;

[0025] Figure 5 It is a schematic diagram of a lower template and a lower template fixing assembly of an embodiment of the utility model;

[0026] Figure 6 It is an exploded schematic diagram of the mold assembly and the lower template fixing assembly of an embodiment of the utility model.

[0027] In the attached figure:

[0028] 10-injection assembly; 11-injection rod; 12-injection barrel; 13-injection outlet;

[0029] 20-mold assembly; 201-upper mold plate; 202-lower mold plate; 203-concave cavity; 204-screw hole; 205-mold receiving groove; 21-injection port; 22-inner cavity; 23-flow guide; 231-flow groove; 232-fixing hole; 233-narrow section; 234-expansion section; 24-molding cavity;

[0030] 40 - lower template fixing assembly; 41 - first fixing member; 42 - second fixing member; 43 - limiting cavity. DETAILED DESCRIPTION

[0031] In order to make the purpose, advantages and features of the utility model clearer, the utility model is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the utility model. In addition, the structure shown in the drawings is often a part of the actual structure. In particular, the emphasis of each drawing is different, and sometimes different scales are used.

[0032] As used in the present invention, the singular forms "one", "an", "one" and "the" include plural objects, the term "or" is usually used to include the meaning of "and / or", the term "several" is usually used to include the meaning of "at least one", and the term "at least two" is usually used to include the meaning of "two or more". In addition, the terms "first", "second" and "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features defined as "first", "second" and "third" may explicitly or implicitly include one or at least two of the features, "one end" and "the other end" as well as "proximal end" and "distal end" generally refer to two corresponding parts, which include not only endpoints. In addition, as used in the present invention, "installed", "connected", "connected", and one element "set" on another element should be understood in a broad sense, usually only indicating that there is a connection, coupling, cooperation or transmission relationship between the two elements, and the connection, coupling, cooperation or transmission between the two elements can be direct or indirect through an intermediate element, and cannot be understood as indicating or implying the spatial position relationship between the two elements, that is, one element can be in any orientation such as inside, outside, above, below or one side of another element, unless the content clearly indicates otherwise. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, directional terms such as above, below, up, down, upward, downward, left, right, etc. are used relative to the exemplary embodiments as shown in the figures, with the upward or upper direction toward the top of the corresponding figure, and the downward or lower direction toward the bottom of the corresponding figure.

[0033] The purpose of the utility model is to provide a microneedle injection device to solve the problems of poor needle tip shape and poor microneedle strength of existing microneedle molding.

[0034] Please refer to Figures 1 to 6The utility model provides a microneedle injection device, which includes: an injection assembly 10 and a mold assembly 20; the injection assembly 10 includes an injection rod 11 and a syringe 12, and the syringe 12 has an injection outlet 13; the injection rod 11 is movably arranged on the syringe 12 along the axial direction of the syringe 12; the mold assembly 20 has an injection port 21 and an inner cavity 22 connected to the injection port 21, and the inner cavity 22 is used to accommodate a microneedle mold (not shown). The mold assembly 20 is abutted against the syringe 12, and the injection port 21 is connected to the injection outlet 13; the injection rod 11 and the mold assembly 20 are configured to apply pressure relative to each other, so that the injection rod 11 can push the molding liquid (such as a high-temperature hot-melt polymer material) contained in the syringe 12 out of the injection outlet 13, enter the inner cavity 22 through the injection port 21, and inject it into the cavity of the microneedle mold. Then, a certain pressure is maintained between the injection rod 11 and the mold assembly 20, and the mold assembly 20 is heated, so that the molding liquid can be solidified under the pressure-maintaining state, and finally a microneedle product is formed. The relative pressure here means that the injection rod 11 and the mold assembly 20 are subjected to relative pressure. For example, the injection rod 11 and the mold assembly 20 can be placed in a hot press and realized by the hot press. In addition, the relative pressure can be understood as the relative pressure between the injection rod 11 and the mold assembly 20 gradually increases, and it can also be understood as the relative pressure between the injection rod 11 and the mold assembly 20 remains unchanged (i.e., pressure maintenance).

[0035] A microneedle mold (such as a silicone mold) is a mold used to prepare microneedle products, which can be made, for example, by casting a metal microneedle positive mold; it can be understood that the microneedle mold has a cavity for accommodating a molding liquid (such as a high-temperature hot-melt polymer material). After the molding liquid is injected into the cavity and cured and demolded, a microneedle product (such as a microneedle sheet containing multiple microneedles) can be obtained.

[0036] The dimensional accuracy of the needle tip of the microneedle prepared by using a silicone mold is better than that of the needle tip of the microneedle prepared by using a metal mold. However, a silicone mold is a flexible mold, which is generally difficult to withstand a high pressure holding pressure. Therefore, in the prior art, a hot pressing method is often used to prepare polymer microneedles when a silicone mold is used. However, when the hot pressing method is used, the molding liquid fills the cavity by flowing, and its filling effect is relatively poor. In the microneedle injection device provided in this embodiment, by setting a mold assembly 20, an inner cavity 22 for accommodating the microneedle mold is provided, and the microneedle mold can be supported by the mold assembly 20 after being accommodated in the inner cavity 22 of the mold assembly 20. The mold assembly 20 can be, for example, a metal part, which has a relatively high strength. With such a configuration, the molding liquid can be injected into the microneedle mold in the mold assembly 20 by using a hot press, and the microneedle mold is placed in the mold assembly 20 and can be supported by the mold assembly 20. Further, based on the relative pressure between the injection rod 11 and the mold assembly 20, the pressure holding function can be achieved, and the density and mechanical strength of the prepared microneedle can be improved. It is particularly suitable for silicone molds and microneedles with a relatively large width and depth, and the microneedles prepared therefrom have a better needle tip shape.

[0037] Please refer to Figure 6 , and combined with reference Figure 1 Optionally, the mold assembly 20 includes a detachable upper template 201 and a lower template 202, the injection port 21 is opened in the upper template 201, and the upper template 201 and the lower template 202 are assembled and connected to form the inner cavity 22. The mold assembly 20 is configured to include a detachable upper template 201 and a lower template 202, which can facilitate loading and demoulding of the microneedle mold. The upper template 201 and the lower template 202 can be fastened by bolts, for example. Preferably, the upper template 201 is used to abut against the injection barrel 12, and the injection port 21 opened on the upper template 201 is aligned with the injection outlet 13 on the injection barrel 12 and communicated with each other. In this way, when the injection rod 11 and the mold assembly 20 are relatively pressed, the injection rod 11 squeezes the molding liquid contained in the injection barrel 12 out of the injection outlet 13, and injects it into the microneedle mold contained in the inner cavity 22 through the injection port 21. After curing is completed, the upper template 201 and the lower template 202 can be separated to remove the microneedle mold. It is understandable that in some other embodiments, the mold assembly 20 is not limited to including a two-piece upper template 201 and a lower template 202, but can be a multi-piece type, that is, it can be formed by combining multiple sub-templates.

[0038] Please refer to Figure 4 , and combined with reference Figure 1 and Figure 6Furthermore, the mold assembly 20 further includes a guide 23, which is disposed in the inner cavity 22 and intersects with the extension direction of the injection port 21; the inner cavity 22 forms a molding cavity 24 under the partition of the guide 23; the guide 23 is used to change the flow direction of the molding liquid flowing in from the injection port 21. The microneedle mold is accommodated in the molding cavity 24, and the guide 23 is equivalent to a barrier between the injection port 21 and the microneedle mold, forming a barrier to the injection port 21, changing the flow direction of the molding liquid, and avoiding the molding liquid jet from directly impacting the microneedle mold, thereby improving the distribution uniformity of the molding liquid in the microneedle mold.

[0039] Please continue to refer to Figure 4 Optionally, the flow guide 23 has a flow groove 231 arranged at an angle to the injection port 21, the flow guide 23 is connected to the upper mold plate 201 and covers the injection port 21, one end of the flow groove 231 is connected to the injection port 21, and the other end of the flow groove 231 is connected to the molding cavity 24. The setting of the flow groove 231 can limit the flow direction of the molding liquid, so that the molding liquid can flow to the molding cavity 24 more evenly. Figure 4 In the illustrated example, the guide member 23 has four flow grooves 231, which are arranged in a cross shape, so that the molding liquid can flow into the molding cavity 24 evenly from four directions. It should be understood that the guide member 23 having four flow grooves 231 is only an example and not a limitation of the guide member 23. In other embodiments, the guide member 23 may also have more or less flow grooves 231.

[0040] Please refer to Figure 3 and Figure 4 In an alternative exemplary embodiment, the upper template 201 has a concave cavity 203 on the side facing away from the injection barrel 12, which is adapted to the outer contour of the guide member 23, and a plurality of screw holes 204 are arranged in the concave cavity 203. The guide member 23 has fixing holes 232 corresponding to the screw holes 204, and the guide member 23 can be fixed in the concave cavity 203 of the upper template 201 by passing bolts through the fixing holes 232 and being threadedly connected with the screw holes 204. Preferably, the surface of the guide member 23 facing the injection port 21 is in contact with the upper template 201 except for the flow groove 231, so that the molding liquid flowing into the injection port 21 is limited to flow in the flow groove 231.

[0041] Preferably, the flow channel 231 includes a narrow section 233 and an expansion section 234, wherein the narrow section 233 is located at one end of the flow channel 231 communicating with the injection port 21; and the expansion section 234 is located at one end of the flow channel 231 communicating with the molding cavity 24. The cross-sectional area of ​​the expansion section 234 is larger than the cross-sectional area of ​​the narrow section 233, so that the molding liquid can be decelerated and expanded in the lateral direction when flowing to the molding cavity 24, thereby further improving the uniformity of the molding liquid flowing into the molding cavity 24.

[0042] Please refer to Figure 5 and Figure 6 The lower template 202 has a mold receiving groove 205 that is compatible with the outer contour shape of the microneedle mold. The mold receiving groove 205 constitutes a part of the inner cavity 22 after the lower template 202 is assembled and connected with the upper template 201, that is, a part of the molding cavity 24. The shape of the mold receiving groove 205 is compatible with the outer contour shape of the microneedle mold, and it can play a bearing role on the microneedle mold. It can be understood that through different settings of the guide member 23, the mold receiving groove 205 can be a part of the molding cavity 24, and the mold receiving groove 205 can also completely overlap with the molding cavity 24.

[0043] Preferably, the microneedle injection device further comprises a lower template fixing assembly 40, which is detachably connected to the lower template 202 to define the position of the lower template 202. In use, the lower template 202 is used to be placed on the heating base of the hot press. The lower template fixing assembly 40 can fix the lower template 202 on the heating base to prevent the position of the lower template 202 from moving.

[0044] In an alternative exemplary embodiment, the lower template fixing assembly 40 includes a first fixing member 41 and a second fixing member 42 that are mutually engaged and connected. After the first fixing member 41 and the second fixing member 42 are mutually engaged and connected and assembled, a limiting cavity 43 that matches the contour shape of the lower template 202 is formed. The lower template 202 is accommodated in the limiting cavity 43 and abuts against the cavity wall of the limiting cavity 43. The first fixing member 41 and the second fixing member 42 can be fixed to the heating base by bolts. In this configuration, the position of the lower template 202 can be reliably limited.

[0045] Furthermore, the microneedle injection device further comprises a hot press (not shown), the hot press comprises a pressing component and a heating base, the injection rod 11 is connected to the pressing component, and the mold assembly 20 is placed on the heating base; the pressing component is configured to apply pressure in the direction of the heating base, so that the injection rod 11 and the mold assembly 20 are configured to apply pressure relative to each other. Preferably, the microneedle injection device further comprises the microneedle mold.

[0046] Preferably, the microneedle injection device provided in this embodiment is configured to be used in a negative pressure environment.

[0047] The following is an exemplary description of the steps for using the improved microneedle injection device of this embodiment.

[0048] Step S1: placing the microneedle mold into the inner cavity 22 of the mold assembly 20, specifically, placing it in the mold receiving groove 205, and then assembling and connecting the upper mold plate 201 and the lower mold plate 202.

[0049] Step S2: Add polymer pellets such as PP and PLA into the syringe 12, and the mass of the polymer pellets may be, for example, 1 g to 499 g. Set the hot pressing pressure, which may be set to 0.1 MPa to 5 MPa, and the hot pressing time may be set to 60 s to 600 s. Heat the syringe 12 to melt the polymer pellets therein to form a fluid molding liquid. Furthermore, at this time, it is preferred to evacuate the environment where the hot press is located to form a negative pressure environment, and the vacuum degree may be configured to be -90 kPa, for example.

[0050] Step S3: Start the hot press, and the pressing component applies pressure toward the heating base, driving the injection rod 11 to move toward the injection outlet 13 to squeeze out the molding liquid. The molding liquid passes through the injection outlet 13, the injection port 21, the flow channel 231 and the molding cavity 24 in sequence, and is finally injected into the cavity of the microneedle mold.

[0051] Step S4: When the pressure of the pressing component reaches the set hot pressing pressure, the pressing component stops pressing, the injection rod 11 also stops moving, and the pressure of the molding liquid no longer increases, forming a pressure-maintaining state until the set hot pressing time is reached. The pressure applied by the pressing component to the injection rod 11 helps to increase the polymer density of the microneedle product and reduce the shrinkage ratio. Furthermore, at this time, it is preferred to break the vacuum in the environment where the hot press is located, that is, to restore the environment where the hot press is located to normal pressure, so that a pressure difference is formed between the cavity of the microneedle mold and the external environment. Such a configuration can increase the filling degree of the molding liquid into the cavity of the microneedle mold, which is beneficial to improving the molding quality of the needle tip.

[0052] Step S5: The pressing component rises, the mold assembly 20 can be taken out, the upper template 201 and the lower template 202 are separated, the microneedle mold is taken out, and the microneedle product is obtained by demolding. Preferably, in this step, the mold assembly 20 can also be air-cooled or water-cooled to reduce the risk of scalding and increase the turnover speed of the mold assembly 20.

[0053] In summary, the microneedle injection device provided by the utility model includes an injection assembly and a mold assembly; the injection assembly includes an injection rod and a syringe, the syringe has an injection outlet; the injection rod is movably arranged on the syringe along the axial direction of the syringe; the mold assembly has an injection port and an inner cavity connected to the injection port, the inner cavity is used to accommodate a microneedle mold; the mold assembly is abutted against the syringe, the injection port is connected to the injection outlet; the injection rod and the mold assembly are configured to apply pressure relative to each other. With such a configuration, the microneedle injection device provided by the utility model can be applied to a hot press, and the setting of the injection assembly can inject the molding liquid (such as a polymer material after high-temperature heat melting) into the microneedle mold in the mold assembly by injection, and the microneedle mold is placed in the mold assembly and can be supported by the mold assembly. Further, based on the relative pressure of the injection rod and the mold assembly, the pressure-maintaining function can be realized, and the density and mechanical strength of the prepared microneedle can be improved. It is particularly suitable for microneedles with a large width-to-depth ratio, and the needle tip shape of the prepared microneedle is better.

[0054] It should be noted that the above embodiments can be combined with each other. The above description is only a description of the preferred embodiments of the utility model, and does not limit the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure are within the protection scope of the utility model.

Claims

1. A microneedle injection device, characterized in that: include: Injection components and mold components; The injection assembly comprises an injection rod and an injection cylinder, wherein the injection cylinder has an injection outlet; the injection rod is movably disposed on the injection cylinder along the axial direction of the injection cylinder; The mold assembly has an injection port and an inner cavity connected to the injection port, and the inner cavity is used to accommodate the microneedle mold; the mold assembly is abutted against the injection barrel, and the injection port is connected to the injection outlet; The injection rod and the mold assembly are configured to be pressed against each other.

2. The microneedle injection device according to claim 1, characterized in that: The mold assembly includes a separable upper mold plate and a lower mold plate. The injection port is opened in the upper mold plate. The upper mold plate and the lower mold plate are assembled and connected to enclose the inner cavity.

3. The microneedle injection device according to claim 2, characterized in that: The mold assembly includes a guide member, which is arranged in the inner cavity and intersects with the extension direction of the injection port; the inner cavity forms a molding cavity under the partition of the guide member; the guide member is used to change the flow direction of the molding liquid flowing in from the injection port.

4. The microneedle injection device according to claim 3, characterized in that: The flow guide has a flow groove arranged at an angle to the injection port, the flow guide is connected to the upper template and covers the injection port, one end of the flow groove is connected to the injection port, and the other end of the flow groove is connected to the molding cavity.

5. The microneedle injection device according to claim 4, characterized in that: The flow channel includes a narrow section and an expansion section, wherein the narrow section is located at an end of the flow channel communicating with the injection port; and the expansion section is located at an end of the flow channel communicating with the molding cavity.

6. The microneedle injection device according to claim 2, characterized in that: The lower template has a mold accommodating groove that is compatible with the outer contour shape of the microneedle mold, and the mold accommodating groove constitutes a part of the inner cavity after the lower template is assembled and connected with the upper template.

7. The microneedle injection device according to claim 2, characterized in that: The microneedle injection device further comprises a lower template fixing component, which is detachably connected to the lower template to define the position of the lower template.

8. The microneedle injection device according to claim 7, characterized in that: The lower template fixing assembly includes a first fixing member and a second fixing member that are snap-fitted to each other. After the first fixing member and the second fixing member are snap-fitted to each other and assembled, a limiting cavity that is adapted to the contour shape of the lower template is formed. The lower template is accommodated in the limiting cavity and abuts against the cavity wall of the limiting cavity.

9. The microneedle injection device according to claim 1, characterized in that: The microneedle injection device also includes a hot press, which includes a pressing component and a heating base. The injection rod is connected to the pressing component, and the mold assembly is placed on the heating base. The pressing component is configured to apply pressure in the direction of the heating base.

10. The microneedle injection device according to claim 1, characterized in that: The microneedle injection device further comprises the microneedle mold.

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