Subcutaneous administration device based on interstitial fluid ebb-flow principle

Abstract

The invention discloses a subcutaneous drug delivery device based on the interstitial fluid ebb-flow principle, and relates to the technical field of medical instruments, the subcutaneous drug delivery device comprises a syringe and a microneedle body, a partition plate is fixed in the syringe, and an injection piston driven by an automatic pushing mechanism to move is arranged below the partition plate; the microneedle bodies are distributed on the supporting pad in an array mode, the threaded pipe is driven by rotating the medicine feeding cavity, and therefore the microneedle bodies distributed on the supporting pad in the array mode can be driven to freely adjust the extending length and penetrate into the subcutaneous part of a patient by a proper depth, and the microneedle bodies can be used for conducting subcutaneous treatment on the patient in the mode that the microneedle bodies penetrate into the subcutaneous part of the patient. According to the invention, the medicine is uniformly spread in the subcutaneous tissue of a patient based on the principle of tissue fluid ebb-flow, so that the absorption effect of the medicine can be ensured, the pain and local tissue damage of the patient are not easily caused, and the experience feeling of the patient is improved; the liquid medicine in the syringe is automatically injected into the subcutaneous part of a patient through the microneedle body, so that the flow rate of the liquid medicine can be accurately controlled.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a subcutaneous drug delivery device based on the principle of tissue fluid infusion. Background Art

[0002] With the development of society and the improvement of medical level, people pay unprecedented attention to health. Traditional intravenous, subcutaneous, intramuscular and other methods that require multiple long-term drug administration can no longer meet patients' needs for improving drug efficacy, reducing side effects, precise targeting and high-quality life. Although the existing technology already has a variety of drug administration methods, such as conventional injections, pre-flushed injections, needle-free injections and automatic emergency injection needles, etc., these drug administration methods are effective in specific situations, but they still cannot meet people's needs for accurate, efficient, low-frequency and comfortable drug administration methods.

[0003] Subcutaneous administration is a method of drug administration that delivers drugs locally or systemically through the skin through subcutaneous capillaries to achieve disease treatment. It can be used for the long-term treatment of chronic diseases such as diabetes, allergic skin diseases, epilepsy and other mental illnesses, cardiovascular diseases, digestive system diseases, etc. Because subcutaneous administration can bypass the first-pass effect of the liver and does not cause gastrointestinal damage, it can minimize the attenuation of drug concentration, reduce toxic side effects, and improve the efficiency of medication, so it has been widely promoted and applied.

[0004] Traditional subcutaneous drug administration is mainly based on needle injection, which can easily cause pain and local tissue damage, resulting in poor patient experience and individual differences among patients. Traditional injection methods are difficult to ensure uniform distribution of drugs subcutaneously, resulting in difficulty in controlling the dosage. In addition, in traditional needle injection methods, some drugs are difficult to diffuse in subcutaneous tissues, thereby affecting the absorption effect. Therefore, the present invention proposes a subcutaneous drug administration device based on the principle of tissue fluid injection to solve the problems existing in the prior art. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to propose a subcutaneous drug delivery device based on the principle of tissue fluid infusion, so as to solve the problems of poor patient experience, difficulty in controlling the dosage of drugs and difficulty in diffusion of some drugs in subcutaneous tissue in traditional subcutaneous drug delivery methods mainly based on needle injection.

[0006] In order to achieve the purpose of the present invention, the present invention is implemented by the following technical solutions: a subcutaneous drug delivery device based on the principle of tissue fluid infusion, comprising a syringe and a microneedle body, a partition is fixed inside the syringe, an injection piston driven to move by an automatic pushing mechanism is arranged below the partition, a drug outlet tube is fixed at the bottom end of the syringe, a hose is sleeved on the outside of the drug outlet tube, a docking cover is fixed at the bottom end of the hose, a docking tube is fixed at the bottom end of the docking cover through a docking locking mechanism, a drug delivery cavity is fixed at the lower part of the docking tube, a threaded tube is fixed at the bottom end of the drug delivery cavity, a microneedle storage box is threadedly sleeved on the outer side of the threaded tube, the bottom end of the threaded tube is located inside the microneedle storage box and is rotatably connected to a lifting ring slidably connected to the inside of the microneedle storage box, a support pad is fixed at the bottom end of the lifting ring, the microneedle body array is distributed on the support pad, a microfluidic chip connected to the microneedle body is arranged on the inner side of the lifting ring, a needle hole adapted to the microneedle body is opened at the bottom end of the microneedle storage box, and a skin adhesive component is fixed to the outer wall of the microneedle storage box.

[0007] A further improvement is that the automatic pushing mechanism includes a micro motor fixed to the top of the injection barrel and a lifting block slidably arranged above the partition, the output shaft of the micro motor passes through the interior of the injection barrel through a bearing and is fixed with a screw threaded through the lifting block, and a push rod sliding through the partition is symmetrically fixed between the lifting block and the injection piston.

[0008] A further improvement is that a sliding rod is symmetrically fixed to the top of the partition, and the top of the sliding rod slides through the lifting block and is fixedly connected to the top of the inside of the injection cylinder.

[0009] A further improvement is that the docking locking mechanism includes a threaded ring slidably mounted on the outside of the docking tube and a first external thread opened on the outer wall of the docking cover, the inner wall of the threaded ring close to the docking cover is provided with an internal thread adapted to the first external thread, a limiting convex ring is fixed to the outer wall of the docking tube, and an annular groove adapted to the limiting convex ring is opened on the inner wall of the threaded ring.

[0010] A further improvement is that a sealing ring is fixed to the bottom end of the docking cover, and a sealing groove adapted to the sealing ring is opened at the top end of the docking pipe.

[0011] A further improvement is that: exhaust holes are symmetrically opened at the bottom of the drug delivery cavity, and an exhaust semipermeable membrane is fixed inside the exhaust hole.

[0012] Further improvements are: the outer wall of the threaded tube is provided with a second external thread, the inner wall at the top of the microneedle storage box is provided with an internal thread adapted to the second external thread, the inner wall of the microneedle storage box is symmetrically fixed with a limit strip, and the outer wall of the lifting ring is provided with a limit groove adapted to the limit strip.

[0013] A further improvement is that the skin adhesive assembly includes an annular gauze fixed to the lower outer wall of the microneedle storage box and a medical tape fixed on the annular gauze, and the medical tape is symmetrically fixed to the upper surface of the annular gauze.

[0014] The beneficial effects of the present invention are as follows: the present invention distributes the microneedle bodies in an array on the support pad, and drives the threaded tube by rotating the drug delivery cavity, thereby driving the microneedle bodies distributed in an array on the support pad to freely adjust the extension length and penetrate into the patient's subcutaneous tissue to an appropriate depth, so that the microneedles penetrate into the patient's subcutaneous tissue, so that the drug is evenly spread in the patient's subcutaneous tissue based on the principle of tissue fluid flow, which not only ensures the absorption effect of the drug, but also is not easy to cause pain and local tissue damage to the patient, thereby improving the patient's experience, and the injection piston is driven to descend in the injection barrel through the automatic pushing mechanism, so that the drug solution in the injection barrel is automatically injected into the patient's subcutaneous tissue through the microneedle body, so that the flow rate of the drug solution can be accurately controlled, thereby reducing the difficulty of controlling the drug dosage, and can adapt to the individual differences of different patients, and is worthy of wide promotion and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a front view of the present invention;

[0016] Figure 2 is a front cross-sectional view of the present invention;

[0017] Figure 3 is a cross-sectional view of a docking cover and a docking tube of the present invention;

[0018] Figure 4 is a cross-sectional view of the drug delivery chamber and the microneedle storage box of the present invention;

[0019] Figure 5 It is a bottom view of the lifting ring and the support pad of the present invention.

[0020] Among them: 1. syringe barrel; 2. microneedle body; 3. partition; 4. injection piston; 5. drug outlet tube; 6. hose; 7. docking cover; 8. docking tube; 9. drug delivery chamber; 10. threaded tube; 11. microneedle storage box; 12. lifting ring; 13. support pad; 14. needle hole; 15. micro motor; 16. lifting block; 17. screw; 18. push rod; 19. slide rod; 20. threaded collar; 21. first external thread; 22. limiting convex ring; 23. annular groove; 24. sealing ring; 25. exhaust hole; 26. second external thread; 27. limiting strip; 28. limiting groove; 29. ​​annular gauze; 30. medical tape; 31. microfluidic chip. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Subcutaneous administration is a common route of drug administration that involves injecting the drug into the subcutaneous tissue and is a relatively simple and safe method of administration;

[0023] The principle of traditional subcutaneous drug administration is the free diffusion of drugs in subcutaneous tissue. Compared with traditional subcutaneous drug administration, subcutaneous drug administration based on tissue fluid infusion has the following advantages:

[0024] 1. Improve drug efficacy

[0025] Specific regulation of interstitial fluid flow: interstitial fluid flow has unique physiological characteristics and nerve distribution. Drugs injected into specific sites can be combined with the meridian system to enhance the efficacy;

[0026] Improvement of local microcirculation: Local stimulation based on the principle of interstitial fluid infusion can activate local blood circulation and lymphatic return, increase the concentration of drugs in the target tissue, and thus enhance the therapeutic effect;

[0027] 2. Reduce the amount of medication

[0028] Precise delivery: Drug delivery based on interstitial fluid infusion can more accurately deliver drugs to the area that needs treatment, avoid drug distribution in non-target tissues, and reduce drug dosage;

[0029] 3. Reduce side effects

[0030] Strong targeting: drug delivery can be targeted to specific pathological sites, reducing the distribution and metabolic burden of drugs throughout the body and alleviating systemic side effects;

[0031] 4. Promote drug absorption

[0032] Tissue characteristics optimize absorption: subcutaneous tissue in the area of ​​interstitial fluid flow is usually rich in nerves and capillaries, making drugs more easily absorbed and utilized;

[0033] Enhancement of electrophysiological effects: The micro-potential environment at the site of interstitial fluid infusion may enhance the permeability of drug molecules and further improve absorption efficiency;

[0034] 5. Multiple therapeutic effects

[0035] Combined with acupuncture effect: The stimulation of acupoints itself has a certain therapeutic effect, and the synergistic effect of drugs and acupuncture can be achieved through combined drug administration;

[0036] Neuromodulatory effects: When drugs are injected into acupuncture points, they may enhance analgesic and immunomodulatory effects by acting on the local neural network;

[0037] 6. Wide range of applications

[0038] Personalized treatment: Acupuncture-based precision drug delivery can be personalized for specific diseases (such as pain, immune diseases, and endocrine disorders);

[0039] Suitable for various dosage forms: This method is applicable to the development of various dosage forms such as traditional drugs, long-acting preparations, and biological preparations (such as protein drugs);

[0040] 7. Prolong the duration of drug action

[0041] Drug reservoir effect: The special tissue structure of the acupoint area may form a sustained release environment for drugs, thereby prolonging the drug's action time and reducing the frequency of drug administration;

[0042] 8. Patient experience optimization

[0043] Reduce pain: Reasonable selection of acupoints can reduce patients' sensitivity to injection pain and improve comfort;

[0044] Improve compliance: Precise drug administration through acupuncture points can achieve more significant therapeutic effects and higher patient compliance.

[0045] according to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, this embodiment provides a subcutaneous drug delivery device based on the principle of tissue fluid infusion, including a syringe 1 for providing a drug delivery power source and a microneedle body 2 for serving as a drug delivery output end. A partition 3 is integrally formed and fixed in the middle position inside the syringe 1, and an injection piston 4 is provided below the partition 3. The upper half of the injection piston 4 is a plastic part, and the lower half is a plastic part, and is sealed and fitted with the inner wall of the syringe 1. The injection piston 4 is driven by an automatic pushing mechanism and moves up and down in the syringe 1. The injection piston 4 is driven by the automatic pushing mechanism to descend in the syringe 1, so that the drug solution in the syringe 1 is automatically injected into the patient's subcutaneous tissue through the microneedle body 2, so that the flow rate of the drug solution can be accurately controlled, thereby reducing the difficulty of drug dosage control;

[0046] A drug outlet tube 5 connected to the injection barrel 1 is fixed at the center position of the bottom end of the injection barrel 1. A hose 6 is provided as an interference sleeve on the outside of the drug outlet tube 5 to prevent the hose 6 from falling off the drug outlet tube 5. A docking cover 7 is fixed to the bottom end of the hose 6. The soft docking between the drug outlet tube 5 and the docking cover 7 is achieved through the hose 6. A docking tube 8 is docked at the bottom end of the docking cover 7, and the docking cover 7 and the docking tube 8 are docked and fixed by a docking locking mechanism. A drug delivery cavity 9 connected to the docking tube 8 is fixed at the lower part of the docking tube 8. A threaded tube 10 connected to the drug delivery cavity 9 is fixed at the bottom end thereof. A microneedle storage box 11 for accommodating the microneedle body 2 is threadedly sleeved on the outer side of the threaded tube 10. The drug delivery cavity 9, the threaded tube 10 and the microneedle storage box in this embodiment are all made of lightweight, high-strength plastic (polyetheretherketone) or metal material (titanium alloy). The bottom end of the threaded tube 10 is threadedly penetrated into the interior of the microneedle storage box 11 and is rotatably connected to a lifting ring 12 through a sealed bearing. The lifting ring 12 is slidably connected to the interior of the microneedle storage box 11, and the inner side of the lifting ring 12 A microfluidic chip 31 is provided which is connected to the microneedle body 2 and through which the drug solution passes. The top and bottom of the microfluidic chip 31 are respectively provided with a liquid inlet and a liquid outlet, and the liquid inlet and the liquid outlet are connected by a microchannel structure. A support pad 13 is fixed to the bottom of the lifting ring 12. The microneedle body 2 is provided with a plurality of groups, and the plurality of groups of microneedle bodies 2 are distributed on the support pad 13 in a circular array. The drug solution channel on the microneedle body 2 is connected with the liquid outlet at the bottom of the microfluidic chip 31, so that the drug solution can be injected into the microneedle body 2. The outer wall of the needle body 2 is provided with a discharge port for discharging the drug solution. The microfluidic chip 31 of this embodiment is made of transparent polydimethylsiloxane (PDMS) or polymethyl methacrylate (PMMA). The microchannel structure in the microfluidic chip 31 includes a plurality of groups of microchannels with a channel width of 100 to 200 μm and a depth of 50 to 100 μm, which are used for precise drug delivery. Through the setting of the microfluidic chip 31, microfluids can be precisely controlled in a micrometer-scale space.

[0047] The bottom of the microneedle storage box 11 is provided with needle holes 14 distributed in an array, and the needle holes 14 are adapted to the microneedle body 2 for the microneedle body 2 to extend out. The outer wall of the microneedle storage box 11 is fixed with a skin adhesive component for bonding and fixing the microneedle storage box 11 to the patient's skin. The microneedle body 2 is distributed in an array on the support pad 13, and the threaded tube 10 is driven by rotating the drug delivery cavity 9, thereby driving the microneedle body 2 distributed in an array on the support pad 13 to freely adjust the extension length and penetrate the patient's subcutaneous tissue to an appropriate depth, so that the drug is evenly spread in the patient's subcutaneous tissue based on the principle of tissue fluid flow by using the microneedle penetration into the patient's subcutaneous tissue;

[0048] The microneedle body 2 used in this embodiment is made of polylactic acid-glycolic acid copolymer (PLGA) or metal titanium with good biocompatibility. The length of the microneedle body 2 is 300-500 μm, the diameter is 50-100 μm, the needle spacing is 100-200 μm, and the surface of the microneedle body 2 is coated with a biocompatible coating to improve drug stability and reduce skin irritation.

[0049] The automatic pushing mechanism includes a micro motor 15 and a lifting block 16, wherein the micro motor 15 is fixed to the top of the syringe 1 by screws, the lifting block 16 is located above the partition 3 and is slidably arranged inside the syringe 1, the output shaft of the micro motor 15 passes through the syringe 1 through a bearing and is fixed with a screw 17, the screw 17 threadedly passes through the lifting block 16, the bottom end of the screw 17 is rotatably connected to the top of the partition 3 through a bearing, a push rod 18 is symmetrically fixed to the bottom end of the lifting block 16, the bottom end of the push rod 18 slides through the partition 3 and is fixed to the top of the injection piston 4, and a sliding rod 19 that slides through the lifting block 16 is symmetrically fixed between the top of the partition 3 and the top of the syringe 1, which plays a limiting role for the lifting block 16, making the lifting block 16 more stable during movement, and the screw 17 is driven to rotate by the micro motor 15, so that the lifting block 16 threadedly sleeved on the screw 17 is lifted and displaced up and down along the screw 17, and the injection piston 4 is driven to slide in the syringe 1 through the push rod 18 during the lifting and displacement of the lifting block 16.

[0050] The docking locking mechanism comprises a threaded collar 20 and a first external thread 21, wherein the threaded collar 20 is slidably sleeved on the outside of the docking tube 8, the first external thread 21 is provided on the outer wall of the docking cover 7, the inner wall of the threaded collar 20 close to the docking cover 7 is provided with an internal thread, and the internal thread is adapted to the first external thread 21, so that the threaded collar 20 can be threadedly sleeved on the docking cover 7, the outer wall of the docking tube 8 is fixed with a limiting convex ring 22 protruding outward, the inner wall of the threaded collar 20 is provided with an annular groove 23, and the annular groove 23 is adapted to the limiting convex ring 22, which plays a limiting role on the threaded collar 20, and the threaded collar 20 is screwed on the docking cover 7 to drive the top end of the docking tube 8 to be closely docked with the bottom end of the docking cover 7, a sealing ring 24 is fixed at the bottom end of the docking cover 7, a sealing groove is provided at the top end of the docking tube 8, and the sealing groove is adapted to the sealing ring 24, when the docking cover 7 and the docking tube 8 are docked together, the sealing ring 24 is embedded in the sealing groove to improve the sealing between the docking cover 7 and the docking tube 8.

[0051] The left and right sides of the bottom of the drug delivery cavity 9 are provided with exhaust holes 25, and an exhaust semipermeable membrane is fixed inside the exhaust hole 25. The exhaust semipermeable membrane used in this embodiment is made of expanded polytetrafluoroethylene (ePTFE), and a micron / nano-scale porous structure is formed by stretching. The pore size is 0.1-10 μm, and the porosity is greater than 50%, which ensures its air permeability, and the air permeability is better. At the same time, the contact angle is greater than 120°, which prevents liquid penetration and maintains hydrophobicity. Its key function is to allow gas (such as oxygen and carbon dioxide) to pass through, while preventing drug leakage and microbial invasion.

[0052] A second external thread 26 is provided on the outer wall of the threaded tube 10, and an internal thread is provided on the inner wall at the top of the microneedle storage box 11, and the internal thread is adapted to the second external thread 26 to realize a threaded connection between the threaded tube 10 and the microneedle storage box 11. Four groups of symmetrically distributed limit strips 27 are fixed to the inner wall of the microneedle storage box 11, and a limit groove 28 adapted to the limit strip 27 is provided on the outer wall of the lifting ring 12, which limits the lifting ring 12 and prevents the lifting ring 12 from rotating synchronously with the threaded tube 10.

[0053] The skin adhesive component includes a ring-shaped gauze 29 and a medical tape 30, wherein the ring-shaped gauze 29 is fixed to the lower outer wall of the microneedle storage box 11, and the medical tape 30 is symmetrically fixed to the upper surface of the ring-shaped gauze 29. By sticking the medical tape 30 on the patient's skin, the microneedle storage box 11 is fixed on the patient's skin.

[0054] When it is necessary to administer medication subcutaneously to the patient, first immerse the drug outlet tube 5 at the bottom of the syringe 1 in the drug solution, and then use the automatic pushing mechanism to drive the injection piston 4 to rise in the syringe 1 to draw the drug solution into the syringe 1, and then use the skin adhesive component to adhere and fix the microneedle storage box 11 to the position to be administered on the patient's limbs, and then use the hose 6 to interfere with the outside of the drug outlet tube 5, and use the docking locking mechanism to dock and fix the docking cover 7 and the docking tube 8 to achieve the connection between the syringe 1 and the drug delivery chamber 9, and then drive the threaded tube 10 to rotate downward by rotating the drug delivery chamber 9, and the threaded tube 10 rotates downward while driving the threaded tube 10 to rotate downward. The lifting ring 12 descends synchronously, and the lifting ring 12 drives the support pad 13 to descend while descending, until the microneedle bodies 2 distributed in an array on the support pad 13 pass through the needle hole 14 and penetrate into the patient's subcutaneous tissue to an appropriate depth, and then the injection piston 4 is driven to descend in the syringe 1 by the automatic pushing mechanism to inject the drug solution in the syringe 1 into the patient's subcutaneous tissue through the drug outlet tube 5, the hose 6, the docking cover 7, the docking tube 8, the drug delivery cavity 9, the threaded tube 10, the lifting ring 12 and the microneedle body 2. After the drug solution is injected into the patient's subcutaneous tissue, it is evenly spread and transported to the corresponding organs of the human body based on the principle of tissue fluid flow, thus completing the entire subcutaneous drug delivery work.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A subcutaneous drug delivery device based on the principle of tissue fluid infusion, comprising a syringe (1) and a microneedle body (2), characterized in that: A partition (3) is fixed inside the injection barrel (1), and an injection piston (4) driven to move by an automatic pushing mechanism is arranged below the partition (3). A drug outlet tube (5) is fixed at the bottom end of the injection barrel (1), and a hose (6) is sleeved on the outside of the drug outlet tube (5). A docking cover (7) is fixed at the bottom end of the hose (6), and a docking tube (8) is fixed at the bottom end of the docking cover (7) through a docking locking mechanism. A drug delivery cavity (9) is fixed at the bottom of the docking tube (8), and a threaded tube (10) is fixed at the bottom end of the drug delivery cavity (9), and a microneedle receiving tube is threadedly sleeved on the outer side of the threaded tube (10). The microneedle storage box (11) has a bottom end, the threaded tube (10) is located inside the microneedle storage box (11) and is rotatably connected to a lifting ring (12) that is slidably connected to the inside of the microneedle storage box (11); a support pad (13) is fixed to the bottom end of the lifting ring (12); the microneedle bodies (2) are arrayed on the support pad (13); a microfluidic chip (31) that is connected to the microneedle bodies (2) is provided on the inner side of the lifting ring (12); a needle hole (14) that is compatible with the microneedle bodies (2) is opened at the bottom end of the microneedle storage box (11); and a skin adhesive component is fixed to the outer wall of the microneedle storage box (11).

2. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 1, characterized in that: The automatic pushing mechanism comprises a micro motor (15) fixed to the top of the injection cylinder (1) and a lifting block (16) slidably arranged above the partition (3); the output shaft of the micro motor (15) passes through the interior of the injection cylinder (1) through a bearing and is fixed with a screw rod (17) threadedly passing through the lifting block (16); and a push rod (18) slidably passing through the partition (3) is symmetrically fixed between the lifting block (16) and the injection piston (4).

3. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 2, characterized in that: A sliding rod (19) is symmetrically fixed to the top of the partition (3); the top of the sliding rod (19) slides through the lifting block (16) and is fixedly connected to the top of the inside of the injection cylinder (1).

4. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 1, characterized in that: The docking locking mechanism comprises a threaded collar (20) slidably sleeved on the outside of the docking tube (8) and a first external thread (21) provided on the outer wall of the docking cover (7); an internal thread matched with the first external thread (21) is provided on the inner wall of the threaded collar (20) close to the docking cover (7); a limiting convex ring (22) is fixed on the outer wall of the docking tube (8); and an annular groove (23) matched with the limiting convex ring (22) is provided on the inner wall of the threaded collar (20).

5. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 1, characterized in that: A sealing ring (24) is fixed at the bottom end of the docking cover (7), and a sealing groove adapted to the sealing ring (24) is provided at the top end of the docking pipe (8).

6. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 1, characterized in that: The bottom end of the drug delivery cavity (9) is symmetrically provided with exhaust holes (25), and an exhaust semipermeable membrane is fixed inside the exhaust hole (25).

7. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 1, characterized in that: The outer wall of the threaded tube (10) is provided with a second external thread (26), the inner wall of the top of the microneedle storage box (11) is provided with an internal thread matched with the second external thread (26), the inner wall of the microneedle storage box (11) is symmetrically fixed with a limit strip (27), and the outer wall of the lifting ring (12) is provided with a limit groove (28) matched with the limit strip (27).

8. A subcutaneous drug delivery device based on the principle of tissue fluid infusion according to claim 1, characterized in that: The skin adhesive component comprises an annular gauze (29) fixed to the lower outer wall of the microneedle storage box (11) and a medical tape (30) fixed on the annular gauze (29), wherein the medical tape (30) is symmetrically fixed to the upper surface of the annular gauze (29).

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