Multi-layered microneedle patch and method of manufacturing the same

Abstract

Provided is a microneedle patch comprising a substrate part and multiple needle parts protruding from the substrate part. The substrate part consists of a diffusion-proof layer and a base, and each needle part consists of a needle tip, a diffusion-proof layer and a base. The diffusion-proof layer of each needle part is formed between the needle tip and the base of the corresponding needle part. The diffusion-proof layer of the substrate part and the diffusion-proof layer of needle part are one-piece structures, and so are the base of the substrate part and the base of the needle part. The diffusion-proof layer of the microneedle patch can prevent the active ingredients from diffusing to the base, limit the active ingredients to the needle tip and control the carrying quantity thereof.

Claims

1. A microneedle patch, comprising a substrate part and multiple needle parts protruding from the substrate part; the substrate part consisting of a diffusion-proof layer and a base; each needle part consisting of a needle tip, a diffusion-proof layer and a base, and the diffusion-proof layer of each needle part formed between the needle tip and the base of the corresponding needle part; wherein the diffusion-proof layer of the substrate part and the diffusion-proof layer of the needle parts are one-piece structures, and the base of the substrate part and the base of the needle parts are one-piece structures; a thickness of each needle part is 300 μm to 1000 μm, and a thickness of the substrate part is 200 μm to 400 μm; along a thickness measuring line from the base of the substrate part toward the needle tip of the needle part, a thickness ratio of a sum of a thickness of the base of the needle part and a thickness of the diffusion-proof layer of the needle part relative to a thickness of the needle part is 0.54 to 0.81; wherein, a material of the needle tip comprises hyaluronic acid, polyvinylpyrrolidone and a first carbohydrate, wherein a molecular weight of hyaluronic acid ranges from 2000 Dalton to 500000 Dalton, and a weight ratio of hyaluronic acid relative to polyvinylpyrrolidone is 1:0.8 to 1:2; a material of the diffusion-proof layer comprises a second carbohydrate, poly(vinyl alcohol) and 2-hydroxypropyl-β-cyclodextrin, wherein a weight ratio of the second carbohydrate relative to poly(vinyl alcohol) is 1:1.8 to 1:3, and a weight ratio of the second carbohydrate relative to 2-hydroxypropyl-β-cyclodextrin is 1:1.8 to 1:3; and a material of the base comprises a third carbohydrate, poly(vinyl alcohol) and 2-hydroxypropyl-β-cyclodextrin, wherein a weight ratio of the third carbohydrate relative to poly(vinyl alcohol) is 1:1.8 to 1:3, and a weight ratio of the third carbohydrate relative to 2-hydroxypropyl-β-cyclodextrin is 1:1.8 to 1:3.

2. The microneedle patch as claimed in claim 1, wherein the needle tip further comprises glycerol and polysorbate 20.

3. The microneedle patch as claimed in claim 2, wherein the first carbohydrate is selected from the group consisting of: glucose, galactose, sucrose, trehalose, maltose, lactose, dextrin, maltodextrin, β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, glucan and any combination thereof; the second carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof; the third carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof.

4. The microneedle patch as claimed in claim 1, wherein the first carbohydrate is selected from the group consisting of: glucose, galactose, sucrose, trehalose, maltose, lactose, dextrin, maltodextrin, β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, glucan and any combination thereof; the second carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof; the third carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof.

5. The microneedle patch as claimed in claim 4, wherein the needle tip comprises an active ingredient, and the active ingredient comprises an attenuated vaccine, an inactivated vaccine, a virus-like particle, a purified subunit antigen, a recombinant antigen, a synthetic peptide, a recombinant vector, a DNA vaccine, a nucleic acid vaccine, a mucosal immunization or a combined vaccine.

6. The microneedle patch as claimed in claim 1, wherein a weight ratio of hyaluronic acid relative to the first carbohydrate is 1:5 to 1:8.

7. A method of manufacturing the microneedle patch as claimed in claim 1, comprising the following steps: step (a): providing a master mold having a datum plane and multiple holes, and the multiple holes formed by recessing from the datum plane; step (b): filling the multiple holes with a needle tip solution, wherein a solid content of the needle tip solution is more than 5 wt % and less than 40 wt %; the needle tip solution comprises hyaluronic acid, polyvinylpyrrolidone and a first carbohydrate, wherein a molecular weight of hyaluronic acid ranges from 2000 Dalton to 500000 Dalton, and a weight ratio of hyaluronic acid relative to polyvinylpyrrolidone is 1:0.8 to 1:2; step (c): drying the needle tip solution to form a needle tip, wherein a surface of the needle tip is lower than the datum plane; step (d): filling the multiple holes with a diffusion-proof solution, and the diffusion-proof solution covers the needle tip and the datum plane, such that a vertical distance between a surface of the diffusion-proof solution and the datum plane is 600 μm to 1500 μm; a solid content of the diffusion-proof solution is more than 30 wt % and less than or equal to 45 wt %, and the diffusion-proof solution comprises a second carbohydrate, poly(vinyl alcohol) and 2-hydroxypropyl-β-cyclodextrin, wherein a weight ratio of the second carbohydrate relative to poly(vinyl alcohol) is 1:1.8 to 1:3, and a weight ratio of the second carbohydrate relative to 2-hydroxypropyl-β-cyclodextrin is 1:1.8 to 1:3; step (e): drying the diffusion-proof solution to form a diffusion-proof layer, wherein the diffusion-proof layer is formed on the needle tip and the datum plane; step (f): filling the multiple holes with a base solution, wherein the base solution covers the diffusion-proof layer in the multiple holes and the diffusion-proof layer on the datum plane, such that a vertical distance between a surface of the base solution and the datum plane is 450 μm to 850 μm; a solid content of the base solution is more than or equal to 30 wt % and less than 45 wt %, and the base solution comprises a third carbohydrate, poly(vinyl alcohol) and 2-hydroxypropyl-β-cyclodextrin, wherein a weight ratio of the third carbohydrate relative to poly(vinyl alcohol) is 1:1.8 to 1:3, and a weight ratio of the third carbohydrate relative to 2-hydroxypropyl-β-cyclodextrin is 1:1.8 to 1:3; the solid content of the base solution is less than the solid content of the diffusion-proof solution; step (g): drying the base solution to form a base, such that the diffusion-proof layer is adhered to and located between the needle tip and the base; and step (h): demolding the needle tip, the diffusion-proof layer and the base that are adhered to each other from the master mold to obtain the microneedle patch.

8. The method of manufacturing the microneedle patch as claimed in claim 7, wherein the needle tip solution further comprises glycerol and polysorbate 20.

9. The method of manufacturing the microneedle patch as claimed in claim 8, wherein based on a total weight of the needle tip solution, a content of glycerol is 0.005 wt % to 0.2 wt %, and a content of polysorbate 20 is 0.001 wt % to 0.1 wt %.

10. The method of manufacturing the microneedle patch as claimed in claim 8, wherein a viscosity of the needle tip solution is 8 centipoises to 25000 centipoises.

11. The method of manufacturing the microneedle patch as claimed in claim 8, wherein a viscosity of the diffusion-proof solution is 5000 centipoises to 220000 centipoises.

12. The method of manufacturing the microneedle patch as claimed in claim 8, wherein a viscosity of the base solution is 3000 centipoises to 100000 centipoises.

13. The method of manufacturing the microneedle patch as claimed in claim 8, wherein the first carbohydrate is selected from the group consisting of: glucose, galactose, sucrose, trehalose, maltose, lactose, dextrin, maltodextrin, β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, glucan and any combination thereof; the second carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof; the third carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof.

14. The method for manufacturing the microneedle patch as claimed in claim 7, wherein in the step (b), a weight ratio of hyaluronic acid relative to the first carbohydrate is 1:5 to 1:8.

15. The method of manufacturing the microneedle patch as claimed in claim 7, wherein in the step (d), the vertical distance between the surface of the diffusion-proof solution and the datum plane is 600 μm to 850 μm.

16. The method of manufacturing the microneedle patch as claimed in claim 7, wherein the first carbohydrate is selected from the group consisting of: glucose, galactose, sucrose, trehalose, maltose, lactose, dextrin, maltodextrin, β-cyclodextrin, 2-hydroxypropyl-β-cyclodextrin, glucan and any combination thereof; the second carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof; the third carbohydrate is selected from the group consisting of: trehalose, amylose, amylopectin, chitin, carboxymethyl cellulose, sodium carboxymethyl cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, hydroxypropyl cellulose, gelatin, chitosan and any combination thereof.

17. The method of manufacturing the microneedle patch as claimed in claim 7, wherein the method comprises: filling the multiple holes with the needle tip solution by vacuum evacuation and centrifugation in the step (b); filling the multiple holes with the diffusion-proof solution by vacuum evacuation and centrifugation in the step (d); and filling the multiple holes with the base solution by vacuum evacuation and centrifugation in the step (f).

18. The method of manufacturing the microneedle patch as claimed in claim 7, wherein the needle tip solution comprises an active ingredient, and the active ingredient comprises an attenuated vaccine, an inactivated vaccine, a virus-like particle, a purified subunit antigen, a recombinant antigen, a synthetic peptide, a recombinant vector, a DNA vaccine, a nucleic acid vaccine, a mucosal immunization or a combined vaccine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic figure for demonstrating that the diffusion-proof layer of the microneedle patches of Examples have the expected diffusion-proof effects.

(2) FIG. 2 is a schematic figure for demonstrating that the diffusion-proof layer of the microneedle patches of Comparative Examples do not have the expected diffusion-proof effects.

(3) FIG. 3A to FIG. 3C is a schematic figure for explaining the definition of the wet film thickness in the specification.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) Several microneedle patches and methods for manufacturing the same are exemplified below to illustrate the implementation of the present invention. One person skilled in the art can easily realize the advantages and effects of the present invention in accordance with the contents disclosed in the specification. Various modifications and variations could be made in order to practice or apply the present invention without departing from the spirit and scope of the invention.

(5) Description of Reagents

(6) 1. Hyaluronic acid (HA), molecular weight: 100000 Dalton, purchased from ECHO CHEMICAL CO., LTD.

(7) 2. Polyvinylpyrrolidone (PVP), purchased from WEI MING PHARMACEUTICAL MFG. CO., LTD.

(8) 3. Sucrose, purchased from ECHO CHEMICAL CO., LTD.

(9) 4. Trehalose, purchased from ECHO CHEMICAL CO., LTD.

(10) 5. Polyvinyl alcohol (PVA), purchased from YES TOP APPLIED MATERIALS CO., LTD.

(11) 6. 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), product name: Cavitron W7 HP7 Pharm, purchased from SHANG KO BIOMED CO., LTD.

(12) 7. Glycerol, purchased from ECHO CHEMICAL CO., LTD.

(13) 8. Polysorbate 20 (Tween-20), product name: MASEMUL PS 20, purchased from YUE BA ENTERPRISE CO., LTD.

(14) Preparation of Polymer Materials

(15) The present invention prepared three different compositions of polymer materials for preparing the needle tip solution of the needle tip, the diffusion-proof solution of the diffusion-proof layer and the base solution of the base. Table 1 shows the compositions and their weight ratio of the polymer materials marked with A, B and C.

(16) TABLE-US-00001 TABLE 1 The compositions and their weight ratio of the polymer materials. Mark The compositions and their weight ratio of the polymer materials A HA (molecular weight: 100000 Dalton):PVP:sucrose = 2:2:11 B HA (molecular weight: 100000 Dalton):PVP:trehalose = 2:2:11 C trehalose:PVA:HP-β-CD = 1:2:2

Test Example 1: Viscosity Evaluation

(17) In this test example, suitable amounts of polymer materials A, B and C were dissolved in different solvents to prepare the needle tip solution, the diffusion-proof solution and the base solution with different solid contents, respectively. Meanwhile, glycerol and Tween-20 were additionally added according to Table 2 to obtain test examples. Here, the polymer material A was dissolved in phosphate buffered saline (PBS), and the polymer materials B and C were dissolved in deionized water (DI water). Taking the needle tip solution of Example 1 for example, it comprised 10 wt % of polymer material A, 0.0067 wt % of glycerol, 0.011 wt % of Tween-20 and PBS for the rest. Also, taking the diffusion-proof solution of Example 1 for example, it comprised 40 wt % of polymer material C and 60 wt % of DI water. Again, taking the base solution of Example 1 for example, it comprised 35 wt % of polymer material C and 65 wt % of DI water.

(18) Next, the viscosity of the test examples was measured at a shear rate of 1 s.sup.−1 at 25° C. by a viscometer (model: MCR302, purchased from Anton Parr), and listed in Table 2.

Examples 1 to 9: Microneedle Patch

(19) As shown in Table 2, the foresaid needle tip solution, diffusion-proof solution and base solution were adopted, and then the microneedle patches of Examples 1 to 9 were prepared respectively by following the method below.

(20) First, a master mold with a datum plane and multiple holes was adopted. The multiple holes were formed by recessing from the datum plane, and arranged in array on the master mold. The material of the master mold was polydimethylsiloxane (PDMS), the density of the multiple holes was 266 holes/cm.sup.2, the range of the array-arranged multiple holes was a circle with a diameter of 1.5 cm, and the shape of each hole was the shape of a pyramid. In Examples 1 to 8, the depth of each hole, i.e. the vertical distance between the tip of each hole and the datum plan, was about 580 μm to 620 μm, and the maximum width of each hole, i.e. the maximum inner diameter of the cross-section of each hole that aligned to the datum plane, was about 290 μm to 310 μm. In Example 9, the depth of each hole, i.e. the vertical distance between the tip of each hole and the datum plan, was about 880 μm to 920 μm, and the maximum width of each hole, i.e. the maximum inner diameter of the cross-section of each hole that aligned to the datum plane, was about 440 μm to 460 μm.

(21) Next, 0.1 milliliter (ml) of the needle tip solution was dropped on the master mold and covered the multiple holes thereof by dispenser. Then, the master mold with the needle tip solution was placed into a vacuum oven for evacuation to reduce the pressure to −730 mmHg to −760 mmHg, such that the needle tip solution flowed downward into the multiple holes from the datum plane, and covered the datum plane and all holes. Here, the step could also be conducted by centrifugation; for example, the master mold with the needle tip solution was placed into a centrifuge, and then centrifuged at 2300×g for 6 minutes to make the needle tip solution flow downward into the multiple holes from the datum plane, and covered the datum plane and all holes. Afterwards, the needle tip solution above the datum plane was totally removed by a blade, and the master mold with the needle tip solution was placed into an environment at 30° C. and with the relative humidity (RH) of 20% to 65% for 1 hour to dry the needle tip solution into the needle tip. Here, the thickness of the needle tip (dry film thickness) of the microneedle patches of Examples 1 to 9 indicated the vertical distance between the tip of the hole and the surface of the needle tip, and if the surface of the needle tip was not a flat plane but a concave plane, the thickness of the needle tip (dry film thickness) would be the vertical distance between the tip of the hole and the lowest spot on the concave plane. The ratio of the thickness of the needle tip relative to the depth of the hole of the master mold, i.e., the ratio of the thickness of the needle tip relative to the thickness of the needle part, of the microneedle patches of Examples 1 to 9 were listed in the following Table 3.

(22) Next, 0.8 ml of the diffusion-proof solution was dropped on the master mold formed with the needle tip and covered the multiple holes thereof by dispenser. Then, the master mold with the diffusion-proof solution was placed into a centrifuge, and then centrifuged at 2300×g for 6 minutes to make the diffusion-proof solution flow downward into the multiple holes from the datum plane, and cover the datum plane and the needle tip in all holes. Afterwards, a part of the diffusion-proof solution above the datum plane was removed by a blade to obtain the wet film thickness of the diffusion-proof solution shown in Table 2. For example, the wet film thickness of the diffusion-proof solution being 700 μm indicated that the vertical distance between the datum plane and the surface of the diffusion-proof solution was 700 μm. Then, the master mold with the diffusion-proof solution was placed into an environment at 30° C. and with the RH of 20% to 65% for 24 hours to 48 hours to dry the diffusion-proof solution into the diffusion-proof layer. The diffusion-proof layer was adhered to the needle tip, and the datum plane, and the master mold formed with the needle tip and the diffusion-proof layer was obtained.

(23) Next, 0.8 ml of the base solution was dropped on the master mold formed with the needle tip and the diffusion-proof layer by dispenser, and covered the multiple holes thereof. Then, the master mold with the base solution was placed into a centrifuge, and then centrifuged at 2300×g for 40 minutes to make the base solution flow downward into the multiple holes from the datum plane, and cover the diffusion-proof layer on the datum plane and the diffusion-proof layer in all holes. Afterwards, a part of the base solution above the datum plane was removed by a blade to obtain the wet film thickness of the base solution shown in Table 2. Then, the master mold with the base solution was placed into an environment at 30° C. and with the RH of 20% to 65% for 24 hours to 48 hours to dry the base solution into the base. The base was adhered to the diffusion-proof layer, i.e. the diffusion-proof layer of the needle part was adhered to and located between the needle tip and the base of the needle part, and the master mold with the final product was obtained. Here, when a shortest distance of a projection point of the tip of the hole on the surface of the base extending toward the tip was set as the thickness measuring line, the thickness ratio of the sum of the thickness of the base of the needle part and the thickness of the diffusion-proof layer of the needle part (i.e., the vertical distance between the surface of the needle tip and the datum plane) relative to the thickness of the needle part (i.e., the depth of the hole of the master mold) of the microneedle patches of Examples 1 to 9 were listed in the following Table 3. Besides, the thickness of the substrate part (i.e., the vertical distance between the surface of the base and the datum plane) of the microneedle patches of Examples 1 to 9 were also listed in the following Table 3.

(24) Finally, the final product was demolded from the master mold with the final product to obtain the microneedle patches of Examples 1 to 9. For explanation, in the method of manufacturing the microneedle patch above, the needle tip solution could comprise active pharmaceutical ingredients or vaccine active ingredients.

(25) As shown in FIG. 1, the microneedle patch 1 of the present invention comprised the substrate part 12 and multiple needle parts 11 protruding from the substrate part 12. The substrate part 12 consisted of the diffusion-proof layer of the substrate part 122 and the base of the substrate part 123, and each needle part 11 consisted of the needle tip 111, the diffusion-proof layer of the needle part 112 and the base of the needle part 113, and the diffusion-proof layer of the needle part 112 is formed between the needle tip 111 and the base of the needle part 113. The diffusion-proof layer of the substrate part 122 and the diffusion-proof layer of the needle part 112 are one-piece structures, and the base of the substrate part 123 and the base of the needle part 113 are one-piece structures. The thickness measuring line L was the shortest distance between the projection point of the tip of the needle part on the bottom plane of the substrate part opposite to the needle part and the tip, and the thickness measuring line L was used for measuring the thickness H.sub.123 of the base of the substrate part 123, the thickness H.sub.113 of the base of the needle part 113, the thickness H.sub.112 of the diffusion-proof layer of the needle part 112 and the thickness Hill of the needle tip 111. As shown in FIG. 1, when measured along the thickness measuring line L, the thickness H.sub.123 of the base of the substrate part 123 equaled to the sum of the thickness of the diffusion-proof layer of the substrate part 122 and the base of the substrate part 123, and could be simplified as the thickness of the substrate part 12. When measured along the thickness measuring line L, the sum of the thickness Hip of the base of the needle part 113, the thickness H.sub.112 of the diffusion-proof layer of the needle part 112 and the thickness H.sub.111 of the needle tip 111 was the thickness of the needle part 11. The ratio of the sum of the thickness H.sub.113 of the base of the needle part 113 and the thickness H.sub.112 of the diffusion-proof layer of the needle part 112 relative to the depth of the hole of the master mold (i.e., the thickness of the needle part) of the microneedle patches of Examples 1 to 9 were also listed in the following Table 3. In addition, when measured along the thickness measuring line L, the sum of the thickness H.sub.123 of the base of the substrate part 123, the thickness H.sub.113 of the base of the needle part 113 and the thickness H.sub.112 of the diffusion-proof layer of the needle part 112 was 550 μm to 1100 μm.

(26) Besides, as follows, the preparing processes of the diffusion-proof layer and the base of the microneedle patch and FIG. 3A to FIG. 3C were adopted for specifically explaining the meaning of the wet film thickness.

(27) As shown in FIG. 3A, a master mold 30 with a needle tip had a datum plane 301, multiple holes 302 formed by recessing from the datum plane 301 and a needle tip 311 formed in the multiple holes 301.

(28) Next, as shown in FIG. 3B, a diffusion-proof solution 32A was filled into the multiple holes 302 and covered the surface of the needle tip 311 and the datum plane 301. Here, a vertical distance H1 between the surface 32B of the diffusion-proof solution 32A and the datum plane 301 was the wet film thickness of the diffusion-proof solution 32A.

(29) Next, as shown in FIG. 3C, the diffusion-proof solution 32A would form a diffusion-proof layer of the needle part 312 on the surface of the needle tip 311 and a diffusion-proof layer of the substrate part 322 on the datum plane 301. Afterwards, a base solution 33A was filled into the multiple holes 302 and covered the surface of the diffusion-proof layer of the needle part 312 and the surface of the diffusion-proof layer of the substrate part 322. Here, a vertical distance H2 between the surface 33B of the base solution 33A and the datum plane 301 was the wet film thickness of the base solution 33A.

Comparative Examples 1 and 2: Microneedle Patch

(30) The methods of manufacturing the microneedle patches of Comparative Examples 1 and 2 were similar to that of Example 8. The main difference was that the wet film thickness of the base solution of the microneedle patches of Comparative Examples 1 and 2 were different from that of Example 8.

(31) TABLE-US-00002 TABLE 2 The compositions and viscosity of the needle tip solution, the compositions, viscosity and wet film thickness of the diffusion- proof solution, and the compositions, viscosity and wet film thickness of the base solution adopted for preparing the microneedle patches of Examples 1 to 9 (E1 to E9) and Comparative Examples 1 and 2 (CE1 and CE2). The diffusion-proof solution The base solution Wet Wet The needle tip solution film film Solid Solid thick- Solid thick- Polymer content Additives Viscosity Polymer content Viscosity ness Polymer content Viscosity ness No. material (wt %) (wt %) (cP) material (wt %) (cP) (μm) material (wt %) (cP) (μm) E1 A 10 glycerol 15-65 C 40 106250- 600- C 35 30000- 640- (0.0067) 143750 700 44000 720 Tween-20 (0.011) E2 A 15 glycerol 130- C 40 106250- 600- C 35 30000- 640- (0.01) 160 143750 700 44000 720 Tween-20 (0.0165) E3 A 20 glycerol 420- C 40 106250- 600- C 35 30000- 640- (0.013) 480 143750 700 44000 720 Tween-20 (0.022) E4 A 25 glycerol 1480- C 40 106250- 600- C 35 30000- 640- (0.0167) 1550 143750 700 44000 720 Tween-20 (0.0275) E5 A 30 glycerol 4750- C 40 106250- 600- C 35 30000- 640- (0.02) 5000 143750 700 44000 720 Tween-20 (0.03) E6 A 35 glycerol 8405- C 40 106250- 600- C 35 30000- 640- (0.023) 11300 143750 700 44000 720 Tween-20 (0.0385) E7 B 15 glycerol 130- C 40 106250- 600- C 35 30000- 640- (0.01) 160 143750 700 44000 720 Tween-20 (0.016) E8 A 20 glycerol 420- C 40 106250- 600- C 35 30000- 480- (0.013) 480 143750 700 44000 520 Tween-20 (0.022) E9 A 16.5 glycerol 170- C 40 106250- 600- C 35 30000- 640- (0.011) 230 143750 700 44000 720 Tween-20 (0.0182) CE1 A 20 glycerol 420- C 40 106250- 600- C 35 30000- 980- (0.013) 480 143750 700 44000 1020 Tween-20 (0.022) CE2 A 20 glycerol 420- C 40 106250- 600- C 35 30000- 1170- (0.013) 480 143750 700 44000 1230 Tween-20 (0.022)

(32) TABLE-US-00003 TABLE 3 The polymer materials of the needle tip, the diffusion-proof layer and the base, the ratio of the thickness of the needle tip relative to the thickness of the needle part, the thickness of the substrate part, the ratio of the sum of the thickness of the diffusion-proof layer and the base of the needle part relative to the thickness of the needle part when measured along the thickness measuring line, the mechanical strength, and the result of diffusion evaluation of the microneedle patches of Examples 1 to 9 (E1 to E9) and Comparative Examples 1 and 2 (CE1 and CE2). The ratio of the sum of the thickness of The ratio the diffusion- of the proof layer and thickness the base of the of the needle part needle relative to the tip relative Polymer thickness of Polymer to the material The the needle part material thickness of the Polymer thickness when measured of the of the diffusion- material of the along the Mechanical Diffusion- needle needle proof of the substrate thickness strength proof No. tip part layer base part(μm) measuring line (N/needle) Effect E1 A 0.275-0.298 C C 260-360 0.702-0.725 0.14 ○ E2 A 0.282-0.315 C C 260-360 0.685-0.718 0.23 ○ E3 A 0.353-0.393 C C 260-360 0.607-0.647 0.29 ○ E4 A 0.368-0.398 C C 260-360 0.602-0.632 0.29 ○ E5 A 0.402-0.428 C C 260-360 0.572-0.598 0.27 ○ E6 A 0.420-0.457 C C 260-360 0.543-0.580 0.22 ○ E7 B 0.325-0.348 C C 260-360 0.652-0.675 0.22 ○ E8 A 0.353-0.393 C C 210-330 0.607-0.647 0.22 ○ E9 A 0.207-0.258 C C 220-350 0.742-0.793 0.3 ○ CE1 A 0.353-0.393 C C 445-462 0.607-0.647 0.16 × CE2 A 0.353-0.393 C C 506-550 0.607-0.647 0.05 ×

Test Example 2: Mechanical Strength Evaluation

(33) The microneedle patches of Examples 1 to 9 and Comparative Examples 1 and 2 were placed in a moisture-proof box for 2 days, and then the mechanical strength of each microneedle patch was measured by a universal testing machine (model: 3343, purchased from INSTRON). In this test example, a compressive test with the displacement set to 10 millimeters (mm) and the speed set to 66 mm/min was conducted, and 500 compressive stress values were received per second at the same time. The mechanical strength of the microneedle patches of Examples 1 to 9 and Comparative Examples 1 and 2 were listed in Table 3.

(34) According to the results in Table 3, the mechanical strength of the microneedle patches of Examples 1 to 9 were all higher than 0.058 N/needle, and thus could pierce the stratum corneum without breakage. Moreover, the mechanical strength of the microneedle patches of Examples 2 to 9 was all higher than 0.2 N/needle, and the microneedle patches of Example 9 had the best mechanical strength as 0.3 N/needle. In contrast, the mechanical strength of the microneedle patch of Comparative Example 2 was only 0.05 N/needle, and was apparently hard to pierce the stratum corneum and prone to breakage, thereby affecting the use of the microneedle patch.

Test Example 3: Diffusion-Proof Evaluation

(35) In this test example, a method of observing the fluorescence with double color was adopted to evaluate whether the diffusion-proof layer can effectively prevent the active ingredients in the needle tip from diffusing to the base, and thus control the carrying quantity of the active ingredients in the needle tip of the microneedle patch. During the preparing processes of the microneedle patches of Examples 1 to 9 and Comparative Examples 1 and 2, green fluorescent was added into the needle tip solution with concentration of 29.6 micrograms/milliliter (μg/ml), and red fluorescent was added into the base solution with concentration of 29.6 μg/ml. After the microneedle patches of Examples 1 to 9 and Comparative Examples 1 and 2 were obtained, each microneedle patch was placed into an inverted fluorescence optical microscope (model: NIB410-FL, purchased from NEXCOPE) to observe whether the diffusion occurred between the layers. If the base still showed red fluorescent by observing with the inverted fluorescence optical microscope, it meant that the green fluorescent in the needle tip did not diffuse. As the needle part 11 of the microneedle patch 1 shown in FIG. 1, the diffusion-proof layer of the needle part 112 thereof had diffusion-proof effect for limiting the active ingredients to the needle tip 111, and such result was marked as “o” in Table 3. On the other hand, if the base showed orange fluorescent, it meant that the green fluorescent in the needle tip diffused to the base and mixed with the red fluorescent in the base. As the needle part 21 of the microneedle patch 2 shown in FIG. 2, the diffusion-proof layer of the needle part 212 thereof did not have diffusion-proof effect, and thus the active ingredients diffused from the needle tip 211 to the base of the substrate part 223, and such result was marked as “x” in Table 3.

(36) According to the results in Table 3, all of the microneedle patches of Examples 1 to 9 could effectively prevent the active ingredients from diffusing from the needle tip to the base. In contrast, both of the microneedle patches of Comparative Examples 1 and 2 could not effectively prevent the active ingredients from diffusing from the needle tip to the base. Especially, although the microneedle patch of Comparative Example 1 had the mechanical strength able to pierce the stratum corneum, it still could not prevent the active ingredients from diffusing from the needle tip to the base, thereby affecting the effects of the microneedle patch with the active ingredients.

(37) In conclusion, by controlling the compositions and thickness of the needle tip, the diffusion-proof layer and the base, the prepared microneedle patch of the present invention not only has good mechanical strength beneficial to use, but also effectively prevent the active ingredients from diffusing from the needle tip to the base for limiting the carried active ingredients to the needle tip, thereby accurately releasing the active ingredients to the target position and ensuring achieving the expected effects.

(38) Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention, the disclosure is illustrative only. Changes may be made in the details, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.