Pre-filled microneedle injector for injection of biomacromolecular pharmaceutical preparation

Abstract

The pre-filled microneedle injector comprises a needle cylinder, a piston and a needle head, the needle cylinder is of a hollow structure, a limiting ring is arranged at the open end of the needle cylinder, the piston extends into the needle cylinder from one side of the limiting ring and can move up and down in the needle cylinder, a rubber ring is arranged at the bottom end of the piston, and a pushing handle is arranged at the top of the piston; the needle head is fixed to the side, away from the limiting ring, of the needle cylinder and comprises a connecting part and needle tubes, the connecting part extends out of the needle cylinder, and at least one needle tube is embedded into the connecting part in an in-line mode. The syringe is used for injection of biological macromolecular medicine preparations and complex preparations, especially mRNA vaccines or medicine preparations needing to be pre-filled for micro-injection, the hydrophilic film on the inner wall of the needle cylinder enables biological macromolecular medicines such as the mRNA vaccines or the medicine preparations to be stably stored, and the injection efficiency is improved. And through the limiting buckle, the pre-filled microneedle injector cannot leak in the transportation process or the storage process.

Description

Technical Field

[0001] The utility model belongs to the field of medical instruments, and specifically relates to a pre-filled micro-needle syringe for injecting biomacromolecule drug preparations. Background Art

[0002] Biomacromolecule pharmaceutical preparations are biological preparations that encapsulate and deliver biomacromolecules into the body to ensure and enhance their corresponding biological functions. Relevant biomacromolecules include nucleic acids, proteins, peptides, etc. Vaccines are biological preparations that will show the characteristics of pathogenic microorganisms in the body and are biological preparations that can produce specific immunity in the body; vaccine injection, also known as vaccination, is the injection of vaccine preparations into the human body or animal body to ensure that the immune system recognizes foreign substances, screens and manufactures antibodies to produce antibodies against related pathogens, and enhances the recipient's strong resistance to the disease. mRNA vaccines are vaccines that use molecular copies of messenger RNA (mRNA) to produce immune responses. They deliver mRNA molecules encoding antigens into immune cells, which use them as templates to construct foreign proteins usually produced by pathogens (such as viruses) or cancer cells, and stimulate adaptive immune responses accordingly, teaching the body to recognize and destroy the corresponding pathogens or diseased cells. The mRNA vaccine is structurally composed of mRNA and RNA encapsulated in a delivery system such as lipid nanoparticles, which protects the RNA chain and helps it be absorbed into cells.

[0003] like Figure 1 As shown, the injection reagents of conventional biomacromolecule drugs are usually injected intravenously, intramuscularly or subcutaneously. There are some difficult-to-overcome problems with intravenous injection, such as: a certain injection volume is required to produce an effect; it may cause damage to blood vessels; injected drugs may cause inflammation of the vascular endothelium or inflammation of tissues in other parts; it causes pain to patients; medical care is required to help complete the injection, which is inconvenient to use; low expression levels of nucleic acids in the body, etc.

[0004] Microneedle injection is a new type of local transdermal drug delivery technology, which combines the convenience of plasters and the effectiveness of intradermal injections, avoiding the shortcomings of other drug delivery methods, and has many advantages such as not touching nerves and blood vessels, and being safe, painless, and highly effective in penetration. Figure 2 As shown, microneedle products usually include multiple needles with a skin penetration length generally not exceeding 2 mm. The microneedles can form microchannels in the stratum corneum of the skin, break through the barrier of the stratum corneum of the skin, and promote the penetration of drugs, thereby reducing the accumulation of drugs in the stratum corneum and increasing the drug dosage reaching the epidermis, dermis and subcutaneous tissue. Therefore, microneedle products are widely used to promote transdermal absorption of drugs. In addition, microneedle products are extremely convenient to use, do not require professional training, patients can self-administer drugs, have a low risk of accidental needle stick injuries, and are easy to handle after use.

[0005] When used as a vaccine, mRNA directly expresses antigen proteins in the body's own cells. Intracellular and secretory proteins are presented through the histocompatibility antigen complex (MHC), respectively, and CD8+ and CD4+ T cells are activated at the same time. Pathogens are eliminated by activating cytotoxic T cells to secrete cytokines, B cells to produce neutralizing antibodies, and activating phagocytes. At the same time, mRNA and LNP lipids can further enhance immunogenicity through the "self-adjuvant" effect, thereby improving the protective efficacy of the vaccine. Existing mRNA vaccines are generally injected intramuscularly, and the immune effect is still not ideal. At the same time, it also increases the burden on the liver and has toxicity. Therefore, it is urgent to find an injection method with better immune effect and more suitable for mRNA vaccines to improve the immune effect. According to literature reports and previous studies, compared with other injection methods such as intramuscular injection, the dermis reached by microneedle injection contains abundant antigen-presenting cells. This immune cell is crucial for initiating immune responses and can play a role in the immune response process; and some of the expressed proteins are delivered through lymph nodes to enhance immunity, so the delivery of biomacromolecule drugs through microneedles has the potential to enhance the efficacy. Microneedle injectors deliver biomacromolecule drugs to enhance the immune effect of the dermis and relatively reduce the expression in other organs such as the liver and spleen; thereby achieving local administration, reducing the potential toxicity of drugs to other organs and tissues, having a significant effect of reducing toxicity and increasing efficacy, and providing the body with stronger protection against viruses.

[0006] The existing traditional injection methods are mostly suitable for the administration of traditional small molecule drug preparations, but the actual immune protection efficiency improvement space for biological macromolecules, especially mRNA drug preparations, is limited. To achieve a more efficient immune protection effect, conventional intradermal injection methods are difficult and very unfavorable for clinical practicality. Some special devices such as BD Soluvia TM The pre-filled microinjection system has a needle that is still too long and slightly thick (1.5 mm long, 30G), which is not conducive to intradermal or superficial skin injection, and the pain will be strong; and Soluvia TM It is designed based on conventional live attenuated and recombinant protein vaccines and is used for storage at 2-8°C. However, since mRNA vaccines are mostly stored at extremely low temperatures of -20°C to -80°C, conventional prefilled syringes cannot be effectively preserved. They are prone to leakage under freezing conditions, displacement of the sterile area of ​​the piston, rupture of the tube wall under variable temperature conditions, and poor compatibility between the packaging material interface and the mRNA-LNP preparation.

[0007] At the same time, different types of vaccines require different injection volumes. For highly effective vaccines such as intradermal mRNA vaccines, only about 100 μL, and sometimes even only 50 μL, are needed. This micro-vaccine poses a great challenge to the syringe, and some micro-vaccines also require multiple injections. Therefore, it is urgent to develop a syringe that is suitable for micro-vaccines and does not affect the injection effect. Utility Model Content

[0008] The utility model provides a prefilled microneedle syringe for the injection of biomacromolecule drug preparations. The prefilled microneedle syringe can realize single quantitative injection, with accurate injection volume and low probability of contamination. It adopts multi-needle needles arranged in line, with low injection difficulty. The hydrophilic film on the inner wall of the syringe allows the vaccine to be stably stored, and the limiting buckle prevents the prefilled microneedle syringe from leaking during transportation or storage.

[0009] In order to solve the above problems, the technical solution adopted by the utility model is as follows:

[0010] A prefilled microneedle syringe for biomacromolecule drug preparation injection comprises a syringe, a piston and a needle. The syringe is a hollow structure and a limit ring is provided at one open end. A limit buckle is provided outside the limit ring. A hydrophilic film is etched on the inner wall of the syringe.

[0011] Furthermore, the material of the syringe is one of polycarbonate, polyethylene, polyethylene terephthalate, cycloolefin copolymer, cycloolefin polymer, and high borosilicate glass.

[0012] Furthermore, the syringe is made of high borosilicate glass.

[0013] Furthermore, the hydrophilic film is formed by plasma etching for 1200 seconds.

[0014] Furthermore, the capacity of the syringe is 50 to 200 μl.

[0015] Further, the piston is located in the syringe and can move up and down in the syringe, the needle head includes a connecting portion and at least one needle tube, the exposed length of the needle tube does not exceed 2 mm, and the exposed length here refers to the distance from the front end of the needle tube to the connecting portion. Preferably, the needle head includes four needle tubes arranged in series.

[0016] Furthermore, a push handle is provided at the end of the piston.

[0017] Furthermore, the position-limiting buckle includes two fixing rings and a telescopic rod connecting the two fixing rings.

[0018] Furthermore, the fixing ring is a double-layer slot structure, and the fixing ring can limit the movement of the pre-filled microneedle syringe. Furthermore, the upper fixing ring is used to clamp the push handle, and the lower solid bottom ring is used to clamp the limit ring.

[0019] Furthermore, the telescopic rod comprises an outer rod and an inner rod, the inner rod can move up and down inside the outer rod, the outer rod is provided with at least one limiting hole, and the inner rod is provided with a locking bead matching the limiting hole.

[0020] The utility model has the following beneficial effects:

[0021] 1. The utility model is used for vaccine injection, especially mRNA vaccines that need to be pre-filled for microinjection. The syringe is made of polymer material or high borosilicate glass material, and a plasma etching process is applied to the inner wall of the syringe to form a hydrophilic film. The formation of the hydrophilic film can reduce the contact angle between the preparation and the syringe, thereby increasing the hydrophilicity and then improving the stability, which is convenient for the storage of the pre-filled syringe. The limiting buckle prevents the pre-filled microneedle syringe from leaking during transportation or storage. At the same time, this design can be used for emergency reserves and large-scale use of biomacromolecule drug preparations (especially vaccines) in emergency situations, and is expected to play an important role in the prevention and control of major epidemics.

[0022] 2. The prefilled microneedle syringe provided by the utility model is suitable for microinjection doses (50-200 μl). Some other syringes on the market have too large a capacity, which leads to problems with the accuracy of the injection volume. In addition, the volume required for intradermal injection itself is not large. Some have long single needles, which are difficult to operate. The prefilled microneedle syringe in this application uses a small-volume and small-capacity syringe to achieve a single quantitative injection with accurate injection volume and low probability of contamination. Under the same injection dose, with multiple needles arranged in series, the bioavailability is high and the injection difficulty is low. The single needle on the market cannot stimulate the immune system over a large area, and the resistance during injection is large, and it is difficult for a single injection site to accommodate more preparation liquid. At the same time, the design of the in-line multi-needle microneedle is more in line with the imperfect skin surface in actual operation during injection, thus preventing injection leakage.

[0023] 3. The limit buckle provided by the utility model can limit the position of the push handle and the limit ring of the microneedle syringe, assist the needle cap to effectively prevent leakage, and ensure the storage stability and storage environment safety of the vaccine in the microneedle syringe. At the same time, the use of the microneedle syringe is extremely convenient, does not require too much professional training, patients can administer the medicine by themselves, the risk of accidental needle stick injury is low, the possibility of accidental injury is small, and it is easy to handle after use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the traditional injection method of drug administration;

[0025] Figure 2 Schematic diagram of the principles of different microneedle injection systems;

[0026] Figure 3 The overall structure of the prefilled microneedle syringe of this application is shown in FIG. Figure 1 ;

[0027] Figure 4 The overall structure of the prefilled microneedle syringe of this application is shown in FIG. Figure 2 ;

[0028] Figure 5 for Figure 4 sectional view of

[0029] Figure 6 It is a structural schematic diagram of the limit buckle;

[0030] Figure 7 Schematic diagram of the internal structure of the telescopic rod;

[0031] Figure 8 An example of a 96-well plate injection reagent for measuring encapsulation efficiency;

[0032] In the figure: 1- syringe, 101- limiting ring;

[0033] 2-piston, 201-rubber ring, 202-push handle, 203-straight rod;

[0034] 3-needle, 301-connecting part, 302-needle tube, 303-needle tip;

[0035] 4-limiting buckle, 401-fixing ring, 402-telescopic rod, 403-limiting hole, 404-locking bead, 405-spring, 406-inner rod, 407-outer rod, 5-protective cap, 6-hydrophilic membrane. DETAILED DESCRIPTION

[0036] In order to describe the present invention in more detail, the technical solution of the present invention is described in detail below in conjunction with the accompanying drawings and specific implementation methods. These descriptions are only to show how the present invention is implemented and cannot limit the specific scope of the present invention. The scope of the present invention is defined in the claims.

[0037] Example 1

[0038] like Figure 3 and Figure 4 As shown, this embodiment provides a prefilled microneedle syringe for injection of biomacromolecule drug preparations, comprising a syringe 1, a piston 2 and a needle 3, wherein the syringe and the needle are an integrated structure, as shown in FIG. Figure 5As shown, the syringe is a hollow structure and a limit ring 101 is provided at one end of the opening, and a scale line is provided on the syringe. The maximum effective capacity of the syringe of this embodiment is 200 μl. The syringe of this embodiment is made of high borosilicate glass, which is easy to process and is conducive to the storage of most injection reagents; a hydrophilic film 6 is etched on the inner wall of the syringe, and the hydrophilic film is processed by plasma etching for 1200s. The setting of the hydrophilic film can ensure the storage stability of biomacromolecules. When the hydrophilic film is not added, the hydrophilic effect is not good, and an interface is easily formed on the inner wall of the syringe, which is easy to cause denaturation of biomacromolecules;

[0039] The piston extends from one side of the limit ring and can move up and down in the syringe. A rubber ring 201 is provided at the bottom of the piston, and a push handle 202 is provided at the top. The push handle is disc-shaped. A straight rod 203 is connected to the push handle by injection molding. A rubber ring is provided at the bottom of the straight rod. The syringe below the rubber ring is a closed space, and the injected medicine will not leak from the top of the syringe.

[0040] The needle is fixed on the side of the syringe away from the limiting ring. The needle includes a connecting part 301 and a needle tube 302. Three needle tubes are embedded in series at the end of the connecting part. A needle tip 303 is provided at the end of the needle tube. The length of the exposed part of the needle tube from the connecting part does not exceed 2 mm. The exposed length in this embodiment is 1 mm. The needle cap 5 is provided on the outer sleeve of the needle to protect the needle tip. Compared with other syringes on the market, some syringes have too large capacity, which leads to problems with the accuracy of the injection volume. The prefilled microneedle syringe for the injection of biomacromolecule drug preparations in this application uses a small-capacity syringe to achieve a single quantitative injection, accurate injection volume, low probability of contamination, and a multi-needle needle arranged in series, which is easy to inject and fits the uneven skin surface in actual operation better during injection, preventing injection leakage.

[0041] like Figure 6 and Figure 7As shown, this embodiment also provides a limit buckle 4 for fixing the microneedle syringe, and the limit buckle includes two fixing rings 401 and a telescopic rod 402 connecting the two fixing rings. The fixing ring is a double-layer groove structure. The upper fixing ring is used to clamp the push handle, and the lower solid bottom ring is used to clamp the limit ring. The staff can pull and clamp the fixing ring on the push handle or the limit ring; the telescopic rod includes an inner rod and an outer rod, and the inner rod can move up and down in the outer rod. The inner rod of this embodiment is connected to the fixing ring below, and the outer The rod is connected to the upper fixing ring. In this embodiment, two limiting holes 403 are provided on the outer rod, and a locking bead 404 is provided on the inner rod. A spring 405 is provided inside the locking bead. When the inner rod 406 moves up and down in the outer rod 407, the locking bead moves to the limiting hole and is pushed out under the pressure of the spring, thereby playing the role of locking and limiting. When it is necessary to continue to extend and retract, the locking bead can be pressed to release the lock. The setting of the telescopic rod can adjust the distance between the two fixing rings. This is done so that the limiting buckle can adapt to microneedle syringes with different doses.

[0042] In actual operation, the corresponding biomacromolecule drug preparation, such as a vaccine prefilled can, is loaded into the microneedle syringe, and after the push rod is assembled, it is fixed with a limit buckle and the front end is protected with a protective cap to effectively prevent leakage. After the overall assembly of the syringe is completed, it will be stored in a suitable environment and wait for use. When using the microneedle syringe provided in this embodiment for injection, it is necessary to inject vertically to the injection surface to ensure sufficient and effective injection and administration.

[0043] Example 2

[0044] The structure of this embodiment is basically the same as that of the first embodiment, except that the connection portion of this embodiment extends from the syringe and has four needle tubes embedded in series.

[0045] Example 3

[0046] The structure of this embodiment is basically the same as that of the first embodiment, except that the connection portion of this embodiment extends from the syringe and is embedded in series with a needle tube.

[0047] Test example

[0048] Syringe material screening and hydrophilic film etching process test

[0049] Test sample: finished product of Example 1

[0050] Experimental process: plasma etching, chemical etching;

[0051] Test formulation: mRNA-LNP

[0052] Processing equipment: Vacuum plasma machine (Guangzhou Shanzhun Instrument Equipment Co., Ltd., model VP-R5)

[0053] Etching parameters: vacuum plasma machine VP-R5 power set to 13.56MHz, gas flow rate set to 250mL / min, RFLEVEL set to HI

[0054] Test method: The outer wall of the syringe barrel and the needle part were wrapped with aluminum foil for protection, so that the inner wall part in contact with the preparation could be fully mixed with the plasma. Three treatment times of 300s, 1200s and 1800s were set respectively, and the contact angle between the preparation and the needle wall was compared. The contact angle is the contact angle corresponding to the droplet in a static state. The test results are shown in Tables 1 and 2.

[0055] Contact angle test method and steps: The method is the sessile drop method; the steps are a. determination of the baseline, b. determination of the droplet contour coordinate points, c. calculation of the contact angle value;

[0056] Contact angle testing equipment: Contact angle measuring instrument (Kruess, Germany)

[0057] Table 1: Plasma etching contact angle data (unit: °)

[0058]

[0059]

[0060]

[0061] Table 2: Chemical etching contact angle data (unit: °, N / A in the table means the contact angle cannot be measured)

[0062]

[0063]

[0064] Test results: As shown in Table 1 and Table 2, firstly, compared with the blank tube and the tube treated with chemical etching, the contact angle of the tube treated with plasma etching is reduced to varying degrees. The reduction in contact angle indicates that the hydrophilicity of the tube is improved. The better the hydrophilicity, the higher the stability of the mRNA-LNP stored in the tube. This is because the inner wall of the syringe without a hydrophilic film before treatment is smooth, while the inner wall of the syringe after treatment forms many tiny pits and gullies, which increases the specific surface area of ​​the material surface and improves the wettability of the material surface, making the unstable interface of the inner wall of the syringe smaller after plasma etching, which leads to a decrease in contact angle and an increase in hydrophilicity. Good hydrophilicity can reduce bubbles or surfaces between the liquid and the material, and such bubbles and interfaces are one of the main reasons for the instability and agglomeration of biomacromolecules. At the same time, biomacromolecules are easily adsorbed to the hydrophobic interface to produce large particles, causing inactivation failure. Increasing hydrophilicity can reduce the adsorption of biomacromolecules.

[0065] Secondly, the experiment shows that the hydrophilicity of six materials, polycarbonate, polyethylene, polyethylene terephthalate, cycloolefin copolymer, cycloolefin polymer, and high borosilicate glass, can be improved after plasma etching, especially after 1200s of plasma etching. The hydrophilicity of high borosilicate glass is the best. The lowest contact angle of the tube after using high borosilicate glass as the tube and plasma etching for 1200s is 32.63°, while the contact angle of the corresponding blank group is 42.55°. The contact angle changes of chemical etching are not obvious.

[0066] Therefore, it is best to use high borosilicate glass as the syringe material for the pre-filled mRNA-LNP reagent, and the 1200s ion etching process can effectively improve the hydrophilicity, which is beneficial to the pre-filled storage of the preparation and maintain the vaccine effect.

[0067] Storage stability test of prefilled microneedle syringe

[0068] Test sample: The finished product of Example 1 after a 1200s hydrophilic film plasma etching process, pre-filled with mRNA vaccine (mRNA-LNP), where the mRNA vaccine contains mRNA (nucleic acid) and a corresponding carrier reagent (LNP) for delivering mRNA drugs.

[0069] Test method: On the day of preparation (Day 0), the stock solution was added to the microneedle syringe of Example 1. The microneedle syringe was placed at 4°C to observe the stability after one week and measure the particle size, encapsulation efficiency, polymer dispersibility index and effective drug loading.

[0070] Test operation steps:

[0071] 1. Pre-mixed reagents:

[0072] (1) Prepare aqueous buffered saline solution (pH 7.4) according to the following table and store at 4°C for future use. See Table 3 for details.

[0073] Table 3: Aqueous buffer solution (pH 7.4) preparation conditions

[0074]

[0075] (2) In addition, a small amount of aqueous buffered saline solution with a pH of 5.5 is prepared. Glacial acetic acid is added to the aqueous buffered saline solution (pH 7.4) to adjust the pH to 5.5 to obtain an aqueous buffered saline solution (pH 5.5).

[0076] The diluent used an aqueous buffered saline solution with a pH of 7.4, and sucrose was additionally added as a cryoprotectant. The sucrose concentration in the diluent was 87 mg / mL.

[0077] (3) The lipid mixed solution used was prepared from four lipid solution mother solutions stored in a -20°C refrigerator. After thawing and dissolving at room temperature, ultrasonication was performed. 0.275 mL of each of the four high-concentration lipid mother solutions was taken and mixed evenly to obtain the final organic phase lipid solution (total lipid concentration was 15.44 mg / mL).

[0078] (4) Use mRNA-LNP to prepare an aqueous mRNA solution. The concentration of mRNA-LNP is 960.4 μg / mL. The concentration of the aqueous mRNA solution required for this experiment is 200 μg / mL. The mRNA-LNP is diluted 4.8 times, that is, 600 μL of mRNA-LNP is taken, and then the aqueous buffer salt solution (pH 5.5) obtained in the above step (2) is taken, and the two are mixed evenly to obtain an aqueous mRNA solution.

[0079] 2. Preparation of carrier reagent (LNP) and mRNA-LNP samples

[0080] mRNA-LNP was prepared by a microfluidic nanodrug preparation system in a ratio of 3:1: aqueous mRNA solution (200 μg / mL): organic lipid solution (total lipid concentration of 15.44 mg / mL). The system parameters were a flow rate of 12 mL / min, a preparation volume of 3.6 mL, an initial waste liquid of 0.3 mL, and a terminal waste liquid of 0.05 mL.

[0081] The prepared mRNA-LNP was immediately diluted 20 times with aqueous buffer saline (pH 7.4) and then diluted 10 times by volume. It was then concentrated by centrifugation through an ultrafiltration centrifuge tube (centrifugation conditions: 2500 g, 4 ° C, 10 min). The solution in the lower part of the ultrafiltration centrifuge tube was discarded until the volume in the upper part of the ultrafiltration tube was close to the initial mRNA-LNP volume, which was the final mRNA-LNP sample. A total of 3.5 mL of sample was collected.

[0082] 3. Sample packaging

[0083] The prepared mRNA-LNP sample was dispensed into the microneedle syringe of Example 1:

[0084] (1) Observation and cleaning of microneedles: After cleaning with sterile water, rinse the inner wall of the syringe with PBS buffer, wipe the inner and outer surfaces of the syringe with sterile paper, and let it dry.

[0085] (2) Packaging: When loading the sample into the microneedle syringe, first remove the piston, use a pipette to inject the sample into the syringe, then install the piston, carefully expel the bubbles, and place the microneedle syringe vertically downward on the steel frame.

[0086] (3) The microneedle syringes were stored at 4°C for future use, with 0.2 mL of sample retained in each microneedle syringe for a total of three parallel samples. After being stored for one week, they were frozen and thawed, and visual inspection revealed no significant changes in the appearance of the samples.

[0087] 4. Measurement of particle size and PDI

[0088] Day 0: Take 50 μL of the prepared mRNA-LNP sample solution, add it to the microneedle syringe of Example 1, then inject it into a 2 mL centrifuge tube and measure the particle size.

[0089] Day 7: Take out the microneedle syringe of Example 1 containing the sample at 4°C and place it on a clean bench to equilibrate to room temperature. Then inject the sample in the microneedle syringe into a 2 mL centrifuge tube for later use. Then repeat the experimental operation of measuring the particle size (Size) in Day 0 and calculate the polymer dispersibility index (PDI).

[0090] 5. Measure the encapsulation efficiency

[0091] The encapsulation efficiency was measured by RNA fluorescence (Ribogreen) detection kit, and the specific method is as follows:

[0092] (1) Take the mRNA-LNP sample and RNA fluorescence (Ribogreen) detection kit in a 2 mL centrifuge tube and place it on a clean bench to equilibrate to room temperature.

[0093] (2) Prepare TE buffer (1X TE buffer) and lysis buffer (Triton buffer) and store them in a 4°C refrigerator.

[0094] (3) Take a 96-well black plate, add 15uL of mRNA-LNP sample to wells 1 to 11 in row A and add 1X TE buffer to a total volume of 250uL to prepare sample dilution solution, and add one well of PBS buffer to well 12 in row A.

[0095] (4) Figure 8 Samples were added as shown, where rows B and C contained 50uL 1X TE buffer plus 50uL A sample diluent, and rows D and E contained 50uL Triton buffer plus 50uL A sample diluent.

[0096] (5) Prepare the standard solution. The preparation conditions are shown in Table 4.

[0097] Table 4: Preparation conditions of the standard solution

[0098]

[0099] (6) Then, the above-mentioned 5 different concentrations of 2.5 μg / mL, 1 μg / mL, 0.5 μg / mL, 0.25 μg / mL, and 0.1 μg / mL standard solutions were added to the sample wells of rows F and G in the 96-well plate, respectively. After standing in the dark for 10 minutes, the fluorescent colorimetric solution was added, and the fluorescence was detected on the microplate reader, and the encapsulation efficiency results were calculated.

[0100] (7) On Day 0 and Day 7, measure the encapsulated mRNA efficiency according to step (6).

[0101] (8) The effective drug content (EE%) was measured by fluorescence analysis.

[0102] The above-mentioned measured particle size, polymer dispersibility index, effective drug loading amount, and encapsulation efficiency are shown in the following table:

[0103] Table 5: Test results of various parameters of stability performance

[0104]

[0105] Analysis of test results: After observing the appearance of the microneedle syringe, the reagent in the syringe is not turbid, and the color and uniformity are consistent with those when pre-filled. The results of particle size and polymer dispersibility index show that the particle size of the syringe treated with plasma etching remains stable after one week of storage of the pre-filled preparation, and the PDI is less than 0.2, which is in the ideal range, indicating that the preparation has good dispersibility. The data of the effective drug loading amount indicate that the effective drug concentration meets the test requirements, and the data of the encapsulation rate indicate that the encapsulation process is successful and efficient. The above data illustrate that the storage stability of the biomacromolecule drug preparation after pre-filling and injection into the microneedle syringe provided by the utility model is good, and does not affect the properties of the biomacromolecule drug preparation. Specifically, this mRNA preparation system can be pre-filled and stably stored in the present microneedle syringe. Further, when the mRNA-LNP is injected through the microneedle structure with a finer inner diameter, it can maintain a stable structure and performance, so that it can be injected into the body to play a good biological role.

[0106] Animal injection test

[0107] Experimental method: The back of mice was depilated one day in advance. On the day of the experiment, the preparation dyed with carmine was sucked into the microneedle syringe, and then injected intradermally and observed. Each animal was injected with 50μL of the agent, and then tissue observation was performed. It can be seen that effective intradermal injection was achieved, and there was no redness, swelling or bleeding on the surface of the animal skin. However, there was a certain error in the 50μL agent measured by the conventional syringe during the operation. Secondly, leakage and exudation occurred on the surface of the animal skin injected with the conventional syringe. The injection test shows that the reagent measurement of the prefilled microneedle syringe is more accurate, the injection operation is simpler, and it is easy to popularize, which is conducive to improving clinical compliance.

[0108] Although the utility model is disclosed as above, the utility model is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the utility model. Therefore, the protection scope of the utility model shall be subject to the scope defined by the claims.

Claims

1. A prefilled microneedle syringe for injection of biomacromolecule drug preparations, characterized in that: It comprises a syringe, a piston and a needle. The syringe is a hollow structure and a limiting ring is arranged at one open end. A limiting buckle is arranged outside the limiting ring. A hydrophilic film is etched on the inner wall of the syringe.

2. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 1, characterized in that: The syringe is made of one of polycarbonate, polyethylene, polyethylene terephthalate, cycloolefin copolymer, cycloolefin polymer, and borosilicate glass.

3. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 2, characterized in that: The syringe is made of high borosilicate glass.

4. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 1, characterized in that: The capacity of the syringe is 50 to 200 μl.

5. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 1, characterized in that: The piston is located in the syringe and can move up and down in the syringe. The needle head includes a connecting portion and at least one needle tube. The exposed length of the needle tube does not exceed 2 mm.

6. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 1, characterized in that: The limiting buckle comprises two fixing rings and a telescopic rod connecting the two fixing rings.

7. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 6, characterized in that: The fixing ring is a double-layer card slot structure, and the fixing ring can limit the movement of the pre-filled microneedle syringe.

8. The prefilled microneedle syringe for biomacromolecule drug preparation injection according to claim 7, characterized in that: The telescopic rod comprises an outer rod and an inner rod, wherein the inner rod can move up and down inside the outer rod, the outer rod is provided with at least one limiting hole, and the inner rod is provided with a locking bead matching the limiting hole.

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