Glucagon-loaded microneedle patch

Abstract

The application discloses a glucagon-loaded microneedle patch, which comprises an array of a plurality of microneedles and a substrate, and each microneedle comprises a needle tip, a needle body and a substrate surface, characterized in that the microneedle patch is made of a polymer and a solubilizing agent and contains glucagon. When the ratio of the length of the microneedle to the distance between the needle tips of adjacent microneedles is 1.2-1.7, the longer the length of the microneedle, the faster the transdermal rate of glucagon. The needle body and the substrate of the glucagon-loaded microneedle patch of the application both carry glucagon, and the glucagon is administered transdermally, has the characteristics of initial burst release and subsequent slow release, has a quick onset and a long action time, and can be used for rescue treatment of hypoglycemia.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical inventions, in particular to a protein drug soluble microneedle as a delivery carrier to achieve rapid in vivo delivery of protein drugs. BACKGROUND

[0002] With the change of life style and the growth of the aging population, the number of diabetic patients is increasing year by year. At present, the key measure to treat diabetes is to strictly control blood glucose level. However, strict intensive hypoglycemic therapy will increase the incidence of hypoglycemia. Hypoglycemia is serious and can cause irreversible damage to the body if not treated in time. If not treated in time, persistent severe hypoglycemia can cause loss of consciousness, permanent nerve damage, and even death. It is reported that type I diabetic patients spend nearly $2000 per year to control hypoglycemia, but still 4% of patients die of hypoglycemia. For the rescue of hypoglycemia, the domestic method is mainly through oral administration of food containing monosaccharides or intravenous injection of 50% glucose solution. However, this method often exceeds the recommended amount of carbohydrates, resulting in poor blood glucose control. Foreign countries mainly use intravenous or subcutaneous injection of glucagon to rescue hypoglycemic patients.

[0003] Glucagon was first discovered to have a blood glucose-raising effect in 1922 and was introduced into diabetes care treatment in 1955. Glucagon is easy to reconstitute and aggregate in water, and the initial glucagon injection has a storage time of only 24 h. In order to solve this problem, Eli Lilly, Novo Nordisk and Fresenius Kabi companies in the United States have developed glucagon lyophilized powder injection. Although the shelf life barrier has been overcome, the "complicated administration process" problem still exists. First, the blood glucose level needs to be monitored, and the dose for adults and children is designed according to the blood glucose value. Then, the insulin lyophilized powder needs to be mixed with a special diluent and loaded into a special syringe for administration. This process has many steps, which is not conducive to the rescue of hypoglycemia. In addition, the half-life of glucagon (only 5 min) is much shorter than that of insulin (2 h), and when treating hypoglycemia, the blood glucose often rises and then falls again, usually requiring two treatments. In the research and investigation of the use of insulin lyophilized powder injection, 64% of the respondents claimed that the glucagon lyophilized powder injection is complex to use, and people often cannot manage themselves when they experience severe hypoglycemia. Another dosage form currently on the market is insulin lyophilized powder nasal spray. This preparation has two disadvantages: (1) it is easily affected by temperature, and when the environmental temperature is low, glucagon is not easily absorbed by the nasal mucosa, affecting the drug efficacy; (2) patients often lose consciousness due to hypoglycemia, making it difficult to actively inhale the drug.

[0004] With the development of pharmaceutical technology, the application of glucagon in the rescue of hypoglycemia has gradually expanded, but it is still necessary to optimize the treatment of hypoglycemia and improve the applicability of glucagon by combining modern pharmaceutical technology.

[0005] Micro-needles are arrays of multiple small needle bodies, the diameter of which is generally less than 300 μm, and the length of which is generally in the range of 200 μm to 2000 μm. Compared with traditional transdermal drug delivery formulations, micro-needles have the advantage of being able to quickly deliver biological macromolecular drugs that are not easily absorbed by the gastrointestinal tract, such as proteins, polypeptides, antibodies, vaccines, RNA and DNA, etc. Micro-needles can be divided into four categories according to the preparation process and material properties, namely solid micro-needles, coated micro-needles, dissolvable micro-needles and hollow micro-needles. Among them, dissolvable micro-needles are the most widely studied and the focus of micro-needle drug delivery systems. Dissolvable micro-needles are micro-needles with water-soluble or biodegradable polymers as the matrix, which can well maintain the activity of polypeptides, proteins, stem cells and drug-loaded vesicles, and can achieve convenient and efficient drug delivery through the minimally invasive stratum corneum of the skin. There have been reports on the use of dissolvable micro-needles for insulin and glucagon delivery. However, the transdermal drug delivery rate of the above-mentioned formulations cannot meet the time requirements of clinical emergency, and they cannot achieve the rescue treatment of hypoglycemia. Therefore, they can only be used as prophylactic formulations for hypoglycemia. Based on the outstanding advantages of micro-needle drug delivery and the current research status, there is a great development space for micro-needles in the delivery of glycemic control drugs, but so far there has been no report on micro-needle drug delivery systems for the rescue of hypoglycemia. SUMMARY

[0006] In view of the shortcomings of the prior art, the present application provides a glucagon-loaded micro-needle patch, which is a dissolvable micro-needle used for the rescue of hypoglycemia.

[0007] The glucagon-loaded micro-needle patch of the present application is made of a polymer and a solubilizing agent, and includes an array of multiple micro-needles and a substrate. Each micro-needle includes a needle tip, a needle body and a substrate surface. Suitable polymers include, but are not limited to, polyvinyl alcohol, polylactic acid, silk fibroin, sodium carboxymethyl cellulose, chitosan, alginate, hyaluronate and polyvinyl pyrrolidone, etc., which can be used alone or in combination in the present application. Among them, polyvinyl pyrrolidone is more preferred to avoid the precipitation of glucagon and the polymer due to coagulation. Solubilizing agents include, but are not limited to, trehalose, maltose, sucrose, mannose, xylitol, lactose, galactose and glucose, etc., which can be used alone or in combination in the present application. Among them, trehalose is more preferred to accelerate the dissolution time of the micro-needle and significantly increase the mechanical strength of the micro-needle.

[0008] The shape of the micro-needle includes, but is not limited to, a conical shape, a nail shape and a prismatic shape. Among them, the conical shape is more preferred to facilitate the penetration of the micro-needle into the skin. Each micro-needle includes a needle tip, a needle body and a substrate surface, and the substrate surface is the surface of the needle body in contact with the substrate of the patch.

[0009] An embodiment of the glucagon-loaded microneedle patch, the length of the microneedle from the tip to the base surface ranges from 1500 μm to 3000 μm, preferably from 1800 μm to 2500 μm.

[0010] Another embodiment of the glucagon-loaded microneedle patch, the microneedle is conical, and the base surface has a diameter ranging from 500 μm to 1000 μm, preferably from 500 μm to 850 μm.

[0011] The glucagon-loaded microneedle patch can be smoothly inserted into the skin, deliver glucagon, and achieve rapid blood glucose rebound. The drug in the base of the patch diffuses into the subcutaneous tissue, prolonging the glycemic time of the drug and avoiding the phenomenon of blood glucose rebound followed by a decrease again due to the short half-life of glucagon.

[0012] The glucagon-loaded microneedle patch is composed of a plurality of glucagon-loaded microneedles arranged in a certain pattern. Generally, the distance between each microneedle is equal. Glucagon is prepared into microneedles of different lengths. When the ratio of the length of the microneedle to the distance between the tips of adjacent microneedles is 1.2 to 1.7, the longer the microneedle, the faster the transdermal rate of glucagon. This embodiment can quickly reverse the hypoglycemic condition of the patient and achieve the effect of rescuing hypoglycemia through transdermal administration.

[0013] Another embodiment of the glucagon-loaded microneedle patch, 1 to 3 microneedles, preferably 1 to 2 microneedles, are arranged within a length of 1 mm.

[0014] Another embodiment of the glucagon-loaded microneedle patch, 10 to 100 microneedles, preferably 50 to 100 microneedles, are arranged within an area of 1 cm 2 .

[0015] The common process for manufacturing microneedle patches can be used to prepare the glucagon-loaded microneedle patch of the present application. To facilitate the understanding of the preparation method by those skilled in the art, the present application is exemplified, but not limited, as follows:

[0016] First, an alkaline solution of ethanol is prepared, for example, by mixing ethanol and a PBS aqueous solution (pH 9.0);

[0017] Then, the aforementioned solubilizing agent and the polymer are added to the alkaline ethanol solution to dissolve, obtaining a material solution for preparing the microneedle patch;

[0018] Next, glucagon is added to the above material solution and mixed uniformly, obtaining a working solution for preparing the glucagon-loaded microneedle patch;

[0019] Afterwards, the working solution is added into the prefabricated microneedle patch mold, and placed under reduced pressure, so that the working solution completely enters the microneedle mold hole, and dried at room temperature to obtain the glucagon microneedle patch.

[0020] The mass concentration of glucagon contained in the working solution is 5wt%-30wt%, especially 15wt%-20wt%(more than 20wt%, a viscous colloid is formed, which is not conducive to the preparation of microneedles by vacuumizing, and less than 15wt% will make the microneedles hollow), such as 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt% and 20wt%.

[0021] The mass concentration of the polymer contained in the working solution is 10wt%-40wt%, especially 10wt%-30wt%(more than 30wt% of the polymer will cause agglomeration reaction with glucagon, and less than 10wt% will reduce the strength of the microneedles), such as 10wt%, 11wt%, 12wt%, 13wt%, 14wt%, 15wt%, 16wt%, 17wt%, 18wt%, 19wt% and 20wt%.

[0022] The mass concentration of the solubilizing agent contained in the working solution is 5wt%-20wt%. When trehalose is used, a concentration greater than 10wt% will make the microneedles easily absorb moisture in the air, affect the strength of the microneedles, and increase the difficulty of insertion into the skin, so 5wt%-10wt% is preferred, such as 5wt%, 6wt%, 7wt%, 8wt%, 9wt% and 10wt%.

[0023] The beneficial effects achieved by the technical scheme of the present application are as follows:

[0024] 1. Glucagon can be delivered quickly and safely, so that the blood sugar of the patient can be quickly raised, and the clinical requirements for the rescue time of hypoglycemia can be met.

[0025] 2. The glycemic control time of islet glucagon can be extended, and secondary administration can be avoided due to the short half-life of glucagon, so that the blood sugar of the patient is lowered again after recovery. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 The preparation route of the glucagon soluble microneedle patch is shown.

[0027] Figure 2Figure 1 is a graph of the appearance of various specifications of glucagon-loaded microneedles; wherein A is a scanning electron microscope image of large-size glucagon microneedles, B is a scanning electron microscope image of medium-size glucagon microneedles, C is a scanning electron microscope image of small-size glucagon microneedles, D is a body microscope image of large-size glucagon microneedles, E is a body microscope image of medium-size glucagon microneedles, and F is a body microscope image of small-size glucagon microneedles, with the scale bar being 200 μm;

[0028] Figure 3 Figure 5 is a graph of the displacement and bearing capacity curve of glucagon-loaded microneedles;

[0029] Figure 4 Figure 6 is a graph of the skin pathological puncture of various specifications of glucagon-loaded microneedles; wherein A is a skin pathological puncture graph of large-size glucagon microneedles, B is a skin pathological puncture graph of medium-size glucagon microneedles, and C is a skin pathological puncture graph of small-size glucagon microneedles, with the scale bar being 100 μm;

[0030] Figure 5 Figure 7 is an in vitro release curve of various glucagon-loaded microneedles;

[0031] Figure 6 Figure 8 is an in vitro transdermal release curve of various glucagon-loaded microneedles;

[0032] Figure 7 Figure 9 is a safety evaluation result graph of glucagon soluble microneedle patches; wherein A is a microneedle imprint photo of large-size glucagon microneedles peeled from the skin for 0 hours, B is a microneedle imprint photo of large-size glucagon microneedles peeled from the skin for 3 hours, C is a microneedle imprint photo of large-size glucagon microneedles peeled from the skin for 24 hours, and D is a skin pathological photo of the skin at the microneedle insertion site at the 24th hour after the microneedles were peeled;

[0033] Figure 8 Figure 10 is a blood glucose recovery curve of glucagon-loaded soluble microneedles on a normal rat hypoglycemia model; the arrow in the graph represents the microneedle administration time. DETAILED DESCRIPTION

[0034] The following detailed description of the specific embodiments of the present application is not limited to the textural expression of the preparation process, the substances used, and the amount of the substances used in the glucagon-loaded soluble microneedle embodiments according to the present application, and any pharmaceutical composition containing the glucagon-loaded soluble microneedle embodiments according to the present application falls within the protection scope of the present application.

[0035] Figure 1The preparation route of the glucagon soluble microneedle patch is shown, specifically, glucagon-loaded microneedle patch is prepared by using polyvinylpyrrolidone as a polymer and trehalose as a solubilizing agent, including adding glucagon into the material solution to form a working solution, dropping into a microneedle mold, then vacuum drying, and peeling the microneedle patch from the mold to obtain the glucagon-loaded soluble microneedle.

[0036] Example 1 glucagon soluble polyvinylpyrrolidone microneedle patch

[0037] 70 ml of ethanol and 30 ml of PBS aqueous solution (pH 9.0) were mixed to obtain an ethanol aqueous solution; 10 g of trehalose and 15 g of polyvinylpyrrolidone K90 were mixed uniformly, and 100 g of the above ethanol aqueous solution was added to obtain a material solution.

[0038] 100 mg of glucagon was weighed and added to 2 g of the above material solution to obtain a working solution.

[0039] 0.3 g of the drug-containing matrix material solution was dropped into a microneedle mold with 225 conical holes (1 mm range, 2 needles, 1 cm 2 range, 100 needles) and a hole depth of 800 μm, a maximum hole diameter of 300 μm, and a needle tip distance of 500 μm, and placed under reduced pressure conditions, and the solution completely entered the microneedle mold holes, and dried at room temperature to obtain a glucagon soluble polyvinylpyrrolidone microneedle patch, hereinafter referred to as: small size drug-loaded microneedle, or small size glucagon microneedle, small microneedle or small needle.

[0040] Example 2 glucagon soluble polyvinylpyrrolidone microneedle patch

[0041] 70 ml of ethanol and 30 ml of PBS aqueous solution (pH 9.0) were mixed to obtain an ethanol aqueous solution; 10 g of trehalose and 15 g of polyvinylpyrrolidone K90 were mixed uniformly, and 100 g of the above ethanol aqueous solution was added to obtain a material solution.

[0042] 100 mg of glucagon was weighed and added to 2 g of the above material solution to obtain a working solution.

[0043] 0.3 g of the drug-containing matrix material solution was dropped into a microneedle mold with 225 conical holes (1 mm range, 2 needles, 1 cm 2 range, 100 needles) and a hole depth of 800 μm, a maximum hole diameter of 300 μm, and a needle tip distance of 500 μm, and placed under reduced pressure conditions, and the solution completely entered the microneedle mold holes, and dried at room temperature to obtain a glucagon soluble polyvinylpyrrolidone microneedle patch, hereinafter referred to as: small size drug-loaded microneedle, or small size glucagon microneedle, small microneedle or small needle.

[0044] Example 3 Glucagon soluble PVP microneedle patch

[0045] Take 70 ml of ethanol and 30 ml of PBS aqueous solution (pH 9.0) to mix to obtain an ethanol aqueous solution; take 10 g of trehalose and 15 g of polyvinylpyrrolidone K90 respectively, mix uniformly, add 100 g of the above ethanol aqueous solution to obtain a material solution.

[0046] Take 100 mg of glucagon, add 2 g of the above material solution to obtain a working solution.

[0047] Drop 0.3 g of drug-containing matrix material solution into a microneedle mold with 144 conical holes (1 mm range, 1 needle, 1 cm 2 range, 36 needles) and hole depth 2000 μm, maximum hole diameter 800 μm, needle tip distance 1500 μm, place in a reduced pressure condition, and the solution completely enters the microneedle mold hole, dry at room temperature to obtain a glucagon soluble PVP microneedle patch. Hereinafter referred to as: large size drug-loaded microneedle, or large size glucagon microneedle, large microneedle or large needle.

[0048] Experimental Example 4 Appearance of microneedle patch

[0049] Sample: glucagon microneedles of small, medium and large sizes prepared in Example 1, Example 2 and Example 3.

[0050] Experimental method:

[0051] 1. Scanning electron microscope

[0052] The small, medium and large size glucagon microneedles were fixed with conductive tape, and the morphology of the three microneedles was observed under a scanning electron microscope (SEM, JSM-6330F, Japan) at a voltage of 5 kV to obtain Figure 2 A, Figure 2 B and Figure 2 C.

[0053] 2. Stereoscopic mirror

[0054] The small, medium and large size glucagon microneedles were observed by stereoscopic mirror (S6D, Leica, Germany) to obtain Figure 2 D, Figure 2 E and Figure 2 F, and the size of the needle tip and the needle height was measured.

[0055] Figure 2 The morphology characteristics of the three microneedles are shown. The three microneedles have sharp needle tips, but the microneedle length, base radius and needle tip distance are significantly different.Figure 2 A、 Figure 2 B and Figure 2 C). Under the stereomicroscope, the hollow or bubble features were not observed in the three kinds of microneedles. The length of large-sized drug-loaded microneedle was about 2003 μm, the radius of base was about 810 μm, the distance of tip was about 1500 μm, the ratio of the length of microneedle to the distance of tip of adjacent microneedle was 1.33 Figure 2 D), the ratio of the length of microneedle to the distance of tip of adjacent microneedle was 1.44; the length of medium-sized drug-loaded microneedle was about 1410 μm, the radius of base was about 535 μm, the distance of tip was about 984 μm Figure 2 E), the ratio of the length of microneedle to the distance of tip of adjacent microneedle was 1.43; the length of small-sized drug-loaded microneedle was about 807 μm, the radius of base was about 307 μm, the distance of tip was about 501 μm Figure 2 F), the ratio of the length of microneedle to the distance of tip of adjacent microneedle was 1.61.

[0056] Experimental Example 5 Mechanical properties of microneedle patch

[0057] Samples: Small, medium and large-sized glucagon microneedles were prepared according to Example 1, Example 2 and Example 3, respectively.

[0058] Experimental method:

[0059] Double-sided tape was used to fix the back layer of small, medium and large-sized glucagon microneedle patches on the metal platform of the pressure-tension detector, and the tip of microneedle faced the probe of the instrument. The probe was pressed down to the microneedle, and the displacement and force curves were recorded.

[0060] The large-sized glucagon microneedle had a deformation displacement of 0.4 mm under 0.78 N Figure 3 ); the medium-sized microneedle required 0.2 N to reach a deformation displacement of 0.4 mm, and the small-sized microneedle produced the same deformation displacement under 0.16 N. This result proved that the mechanical strength of microneedle increased with the increase of size.

[0061] Experimental Example 6 Skin insertion performance of microneedle patch

[0062] Samples: Small, medium and large-sized glucagon microneedles were prepared according to Example 1, Example 2 and Example 3, respectively.

[0063] Experimental method:

[0064] Sprague Dawley rats were used as animal models, and the hair of Sprague Dawley rats was removed with a razor, and the exposed skin surface was washed with ethanol. Small, medium and large size glucagon soluble microneedles were vertically inserted into the back skin of rats, respectively, and were peeled off after 5 minutes. The rats were decapitated, the skin was peeled off, the microneedle insertion site was cut and embedded, and was frozen in liquid nitrogen. The section was cut to a thickness of 5 μm and placed on a silane-coated glass slide. The skin section was observed under an inverted microscope (IX-71, Olympus, Tokyo, Japan).

[0065] The skin insertion depth of the microneedle is a key factor affecting drug delivery and therapeutic effect. Figure 4 It was shown that the three microneedles could effectively penetrate the stratum corneum. The transdermal depth of the large size drug-loaded microneedle was about 557 μm Figure 4 A) The transdermal depth of the small microneedle was about 201 μm Figure 4 B), the transdermal depth of the medium size microneedle was about 407 μm Figure 4 C), and the glucagon soluble microneedle was about 201 μm. This result shows that when the microneedle length and the distance from the needle tip are the same, the longer the microneedle length, the better the skin insertion performance. Therefore, the large size drug-loaded microneedle is very beneficial to drug delivery.

[0066] Example 7: In vitro release experiment of microneedle patch

[0067] Samples: Small, medium and large size glucagon microneedles were prepared according to Example 1, Example 2 and Example 3, respectively.

[0068] Experimental method:

[0069] 0.03 g of small, medium and large size glucagon soluble microneedles were placed on a Franz receiving pool containing 10 ml of normal saline, so that the microneedles were completely immersed in 32℃ normal saline, and magnetic stirring was carried out at 300 rpm. At the predetermined time point, the sample solution (1 ml) was taken out, filtered through a 0.22 μm filter, supplemented with an equal amount of fresh normal saline at the same temperature, and the amount of glucagon in the filtrate was determined by liquid chromatography-mass spectrometry.

[0070] The chromatographic conditions were as follows: Agilent C18 column (100 mm x 2.1 mm, 1.7 μm) was selected, column temperature was set to 40℃, mobile phase was 0.1% formic acid aqueous solution and acetonitrile (80:20), flow rate was set to 0.3 ml / min, m / z 871.3-217.4, and sample amount was set to 5 μl.

[0071] The rate of drug release from the preparation is a key factor of the transdermal permeation rate of the transdermal drug delivery system, Figure 5It is shown that the glucagon released from the three kinds of microneedles exceeds 50% after 5 min of dissolution, indicating that the prepared glucagon microneedles have the characteristics of rapid dissolution and drug release, which is beneficial to the rapid transdermal penetration of glucagon.

[0072] In addition, the glucagon released from the three kinds of microneedles reaches 80% within 30 min and has no significant difference, indicating that the size of the microneedle does not affect the release rate of the drug from the preparation.

[0073] Example 8: In vitro transdermal experiment of microneedle patch

[0074] Sample: Small, medium and large size glucagon microneedles were prepared according to Example 1, Example 2 and Example 3, respectively.

[0075] Experimental method:

[0076] Sprague Dawley rats were sacrificed, and the back skin was taken out. Small, medium and large size glucagon soluble microneedles (the mass of the three kinds of microneedles was 0.033 g) were inserted into the back skin, respectively. The skin was fixed between the Franz donor cell and the receiving cell, with the horny layer facing the donor cell. The two diffusion cells were clamped carefully. The effective diffusion area of the diffusion cell was 1.2 cm 2 . 10 ml of 32℃ physiological saline was added to the receiving cell, and stirred at 300 rpm. The sample solution (1 ml) was taken out, filtered through a 0.22 μm filter, supplemented with an equal amount of fresh physiological saline at the same temperature, and the amount of glucagon in the filtrate was determined by liquid chromatography-mass spectrometry. The cumulative drug permeation was calculated.

[0077] Figure 6 It is shown that under the condition that the drug loading of the three kinds of microneedles is the same, the large size microneedle can perform burst release of drug within 15 min, and the cumulative amount of drug penetration (117 μg) is much larger than that of the medium size microneedle (28 μg) and the small size microneedle (12 μg). In addition, the large size microneedle still has slow drug penetration through the skin after 15 min, and the cumulative amount of drug penetration is 225 μg by 3 hours, while the cumulative amount of drug penetration of the medium size and small size microneedles is only 46 μg and 23 μg by 3 hours. It can be seen that the large size microneedle can quickly deliver the drug at the needle tip to the subcutaneous tissue by excellent skin insertion performance. Then, the glucagon diffused from the basal layer diffuses below the skin by virtue of the larger skin pore channel caused by the microneedle, realizing the slow release of the drug. The medium size and small size microneedles do not achieve the desired results due to the smaller skin insertion performance and the smaller skin pore channel caused by the microneedles.

[0078] Example 9: Safety evaluation of microneedle patch

[0079] Samples: Small, medium, and large size glucagon microneedles were prepared according to Example 1, Example 2, and Example 3, respectively.

[0080] Experimental method:

[0081] Sprague Dawley rats were used as animal models, and the hair of the Sprague Dawley rats was shaved using a razor. The large size glucagon soluble microneedle was vertically inserted into the back skin of the rat, and after 3 hours, the microneedle was peeled off, respectively. The microneedle imprint was observed at 0h, 3h and 24h, respectively, and the rat was decapitated at 24h, and whether inflammation occurred in the skin was observed by H&E technology.

[0082] After peeling off the large size glucagon soluble microneedle, it was found that the rat skin would only leave the imprint of the microneedle array, and there would be no redness and blood exudation Figure 7 A); 3h later, the trace of the microneedle array would obviously decrease Figure 7 B); 24h later, the trace on the rat skin completely disappeared Figure 7 C). The skin H&E chart showed that there was no inflammatory cell infiltration at the site of the microneedle insertion after 24h Figure 7 D). The glucagon microneedle patch has good safety.

[0083] Experimental Example 7. Pharmacodynamic study of glucagon soluble polyvinylpyrrolidone microneedle patch

[0084] Samples: Small, medium, and large size glucagon soluble microneedles were prepared according to Example 1, Example 2, and Example 3, respectively.

[0085] Experimental method:

[0086] SD rats (200±10g) were selected as model animals, a total of 30, divided into model group, large size blank microneedle group, small size glucagon soluble microneedle group, medium size glucagon soluble microneedle group, and large size glucagon soluble microneedle group (6 in each group). The back hair of the rats was shaved using a razor, and the initial blood glucose of each group of rats was determined. After 2IU insulin was given, the model group was not treated, and the blood glucose change of the rat was determined at the predetermined time point. The threshold value of drug administration was set to 2.8mmol. When the blood glucose value was lower than the threshold value, the microneedle group rats were administered with microneedle patch on the back, and the blood glucose change was measured at a certain time point.

[0087] As Figure 8The blood glucose level of the model group decreased to 2.5±1.1 mmol after 60 minutes of insulin administration, and remained at the hypoglycemic level without treatment. Similarly, the blood glucose level of the large-size blank microneedle group decreased to 2.6±0.7 mmol after 60 minutes of insulin administration. After administration of the microneedles, the blood glucose level was consistent with that of the model group, and there was no significant difference. It was found that the matrix material (polymer and solubilizer) in the microneedles did not affect the blood glucose level of the rats. After administration of the large-size microneedles for 5 minutes, the blood glucose level increased to 3.5±0.8 mmol. Thereafter, the blood glucose level continued to increase, and the blood glucose level was 5.45±1.1 mmol at 180 minutes. The blood glucose level of the medium-size microneedle group increased slowly, and the blood glucose level was only 3.2±0.7 mmol at 15 minutes after administration of the microneedles. Throughout the process, the blood glucose level of the small-size microneedle group was consistent with that of the model group. The results show that the large-size microneedles can achieve rescue treatment of hypoglycemia.

[0088] The foregoing description of various preferred embodiments of the application has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed. Many modifications and variations are possible in light of this disclosure. It was chosen and described in order to provide the best illustration of the principles of the application and its practical application to thereby enable others skilled in the art to utilize the application in various embodiments and with various modifications as are suited to the particular use contemplated. Thus, it is intended that the scope of the application be defined by the claims appended hereto rather than by the description preceding them.

Claims

1. A glucagon-loaded microneedle patch, characterized by The array and the substrate are composed of a plurality of microneedles, each of which comprises a needle tip, a needle body and a substrate surface, the microneedle patch is made of a polymer and a solubilizing agent and contains glucagon; When the ratio of the length of the microneedle to the distance between the tips of adjacent microneedles is 1.2-1.7, the longer the microneedle, the faster the transdermal rate of glucagon; The polymer is selected from polyvinylpyrrolidone; The solubilizing agent is selected from trehalose; The preparation method of the microneedle patch is as follows: First, an alkaline solution of ethanol is prepared; Then, the solubilizing agent and the polymer are added to the alkaline ethanol solution to dissolve, obtaining a material solution for preparing the microneedle patch; Next, glucagon is added to the material solution and mixed uniformly to obtain a working solution for preparing the glucagon microneedle patch; then, the working solution is added to a pre-prepared microneedle patch mold, placed under reduced pressure, and the working solution is completely introduced into the microneedle mold hole, and dried at room temperature to obtain the glucagon-loaded microneedle patch; The mass concentration of glucagon in the working solution is 5wt%-30wt%; The mass concentration of the solubilizing agent in the working solution is 5wt%-20wt%; The mass concentration of the polymer in the working solution is 10wt%-30wt%.

2. The glucagon microneedle patch of claim 1, wherein Within the length of 1mm, 1-3 microneedles are arranged.

3. The glucagon microneedle patch of claim 1, wherein In the range of 1 cm 2 2 of the area, 10-100 microneedles are provided.

4. The glucagon microneedle patch of claim 1, wherein The length from the needle tip to the substrate surface is 1500μm-3000μm.

5. The glucagon microneedle patch of claim 1, wherein The microneedle is conical in shape.

6. The glucagon microneedle patch of claim 5, wherein The diameter of the substrate surface is 500μm-1000μm.

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