Microneedle mold and microneedle mold kit

Abstract

The application discloses a microneedle mold and a microneedle mold kit, and belongs to the technical field of biomedical materials, wherein the microneedle mold has a microneedle female mold array body and a slope side wall surrounding the microneedle female mold array body; the microneedle female mold array body is a platform with a plurality of microneedle cavities, and the plurality of microneedle cavities are arranged in an array; the slope side wall is higher than the microneedle female mold array body, and the inner wall of the slope side wall is a slope gradually inclined outward from bottom to top; the slope inner wall of the slope side wall is in a planar shape, an outward convex shape or an inward concave shape. The application makes the edges of the formed microneedles smooth, is convenient to use and demold, improves production efficiency, is flexible to use and reduces the cost of the mold.

Description

Technical Field

[0001] This invention belongs to the field of biomedical materials technology, and relates to a microneedle mold, and more particularly to a microneedle mold and a microneedle mold kit. Background Technology

[0002] The general method for scaling up the production of soluble microneedle patches is to prepare large-area soluble microneedle sheets using a large negative mold, and then use cutting tools or equipment such as roller cutters to cut the large soluble microneedles into multiple small-area soluble microneedle sheets of specific shapes. During this process, the large microneedle sheets need to be removed from the mold first. Therefore, it is not suitable to apply a backing adhesive layer before forming the small microneedle sheets. This not only may cause the microneedle substrate to be tilted or broken due to the upward demolding force during demolding, but it will also generate waste microneedle sheets after cutting, resulting in a waste of raw materials.

[0003] The current improved method involves directly preparing soluble microneedles of a specific shape using a small, specially designed female mold. The microneedles are then demolded vertically using an adhesive layer, minimizing the impact of external forces on the needles during demolding and ensuring needle quality and uniformity during scale-up production. Furthermore, the elimination of cutting steps avoids raw material waste and saves costs. However, this improved method still has drawbacks. When the liquid and solid surfaces come into contact, the force between solid surface molecules and liquid molecules is greater than the force between liquid molecules. Under this force, liquid molecules accumulate on the solid surface, reducing surface tension. This causes solvent and solute in the mold liquid at the edges to accumulate at the contact point with the mold. The resulting soluble microneedles have thicker or protruding edges after drying, affecting both the quality of the microneedle product and the adhesion of the backing, ultimately hindering successful demolding.

[0004] In addition, since different products require molds of different specific shapes to minimize costs, a large number of molds of different shapes are needed. Currently, the cost of preparing molds is still high, with the main cost concentrated in the preparation of micron-sized microneedle cavities. Therefore, the cost of scaling up production remains high. Summary of the Invention

[0005] This invention provides a microneedle mold and a microneedle mold kit to overcome the shortcomings of the prior art.

[0006] To achieve the above objectives, the present invention provides a microneedle mold, characterized in that: the microneedle mold has a microneedle female mold array body and a sloping sidewall surrounding the microneedle female mold array body; the microneedle female mold array body is a platform with a plurality of microneedle cavities, the plurality of microneedle cavities being arranged in an array; the sloping sidewall is higher than the microneedle female mold array body, and the inner wall of the sloping sidewall is a slope that gradually slopes outward from bottom to top; the inner wall of the sloping sidewall is planar, convex, or concave.

[0007] Furthermore, the present invention provides a microneedle mold that may also have the following feature: wherein the angle between the inner wall of the slope sidewall or the tangent of the inner wall of the slope sidewall and the bottom surface of the mold is 1-89°.

[0008] Furthermore, the present invention provides a microneedle mold, which may also have the following features: wherein the depth of the microneedle cavity of the main body of the microneedle female mold array is 40-1600μm; and the vertical depth of the slope sidewall is 0.5-10mm.

[0009] Furthermore, the present invention provides a microneedle mold that may also have the following feature: wherein the top edge of the sloping sidewall is provided with at least one overflow outlet.

[0010] Furthermore, the present invention provides a microneedle mold that may also have the following feature: wherein the material of the microneedle mold is one of metal, polydimethylsiloxane, polymethyl methacrylate, ceramic, resin, and polylactic acid.

[0011] Furthermore, the present invention provides a microneedle mold that may also have the following characteristics: the shape of the microneedle cavity of the main body of the microneedle female mold array includes, but is not limited to, conical, pyramidal, spiral, okra-shaped, starfruit-shaped, and platform-reinforced types. The shape of the microneedle mold includes, but is not limited to, square, circular, crescent-shaped, T-shaped, and bone-shaped.

[0012] This invention provides a microneedle mold kit, characterized by the following features: it includes an upper mold cover and the aforementioned microneedle mold; the upper mold cover is a cover-like structure that matches the microneedle mold and can be placed on the microneedle mold; the upper mold cover has a through-hole for defining the shape of the microneedle, the inner wall of which is a slope that gradually slopes outward from bottom to top; when the upper mold cover is placed on the microneedle mold, the microneedle shape defining hole is within the range of the microneedle female mold array body of the microneedle mold, and the bottom of the microneedle shape defining hole abuts against the top surface of the microneedle female mold array body; the microneedle mold only exposes a portion of the microneedle cavity corresponding to the microneedle shape defining hole, and after the mold liquid is introduced and solidified, a microneedle with the same shape as the microneedle shape defining hole is formed; the inner wall of the slope of the microneedle shape defining hole is planar, convex, or concave.

[0013] Furthermore, the present invention provides a microneedle mold kit, which may also have the following feature: wherein the angle between the inner wall of the slope of the hole defined by the microneedle shape or the tangent of the inner wall of the slope and the bottom surface of the mold is 1-89°.

[0014] Furthermore, the present invention provides a microneedle mold kit, which may also have the following features: wherein the vertical depth of the hole defined by the microneedle shape is 0.6-12mm; and the material of the upper mold cover is one of metal, polydimethylsiloxane, polymethyl methacrylate, ceramic, resin, and polylactic acid.

[0015] Furthermore, the present invention provides a microneedle mold kit, which may also have the following features: wherein the upper surface of the upper mold cover is provided with at least one overflow channel, one end of the overflow channel is connected to the microneedle shape defining hole, and the other end extends to the edge of the upper mold cover.

[0016] Furthermore, the present invention provides a microneedle mold kit, which may also have the following feature: wherein at least one side of the upper mold cover has an opening at its bottom.

[0017] The beneficial effects of this invention are as follows: This invention provides a microneedle mold with sloping sidewalls, which reduces the solid-liquid contact angle and minimizes edge protrusion after drying, allowing the microneedles to adhere well to the backing, effectively improving the yield and production efficiency of the microneedles during production. Furthermore, an overflow drain is provided at the top edge of the mold for more precise metering of the molding liquid during scale-up production; excess molding liquid injected into the mold can overflow from the overflow drain. This sloping mold can be made from any shape of mold, flexibly meeting various production needs. The microneedle mold of this invention is convenient to use and demold, reduces solid-liquid edge tension, makes the edges of the molded microneedles smooth, improves production efficiency, reduces mold costs, and combines economy and convenience.

[0018] Meanwhile, this invention also provides a microneedle mold kit, which includes a microneedle mold and a matching upper mold cover. The upper mold cover has a microneedle-shaped defining hole with a sloping inner wall. When the upper mold cover is placed on the microneedle mold, the bottom edge of the microneedle-shaped defining hole can fit tightly with the microneedle mold, exposing a portion of the microneedle cavity of the microneedle mold. The microneedle-shaped defining hole can be designed as any shape with a bottom area smaller than the microneedle cavity range of the microneedle mold, and can solidify into the desired shape after the molding liquid is injected into the microneedle-shaped defining hole. That is, in the microneedle mold kit, the microneedle mold can be equipped with multiple upper mold covers with microneedle-shaped defining holes of different shapes to meet the production needs of microneedles of different shapes. Of course, multiple microneedle-shaped defining holes of different shapes can also be set on one upper mold cover, which can also meet the production needs of microneedles of different shapes. The setting of the upper mold cover further improves the utilization rate and flexibility of the microneedle mold, reduces the number of microneedle mold preparations, saves production costs, and improves production efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the microneedle mold in Example 1;

[0020] Figure 2 This is a top view of the microneedle mold in Example 1;

[0021] Figure 3 This is a cross-sectional schematic diagram of the microneedle mold in Example 1;

[0022] Figure 4 This is a cross-sectional schematic diagram of a microneedle mold for a slope sidewall of other specific shapes in Example 1, where a is a planar inner wall of the slope sidewall and b is a concave inner wall of the slope sidewall.

[0023] Figure 5 This is a schematic diagram of the microneedle mold in Example 2;

[0024] Figure 6 This is a top view of the microneedle mold in Example 2;

[0025] Figure 7 This is a schematic diagram of the microneedle mold kit in the separated state in Example 3;

[0026] Figure 8 This is a schematic diagram of the microneedle mold kit in use as described in Example 3;

[0027] Figure 9 This is a top view of the microneedle mold kit in use in Example 3. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] like Figure 1-3 As shown, this embodiment provides a microneedle mold 1, which has a microneedle female mold array body 11 and a sloping sidewall 12 surrounding the microneedle female mold array body 11.

[0031] The main body 11 of the microneedle mold array is a platform with several microneedle cavities arranged in an array. The sloping sidewall 12 is higher than the main body 11, making the microneedle mold 1 as a whole concave shape. The inner wall of the sloping sidewall 12 is a slope that gradually slopes outward from bottom to top to weaken the tension effect on the edge mold liquid during solidification. Figure 3 As shown, in this embodiment, the inner wall of the slope sidewall 12 is convex. Of course, the inner wall of the slope sidewall 12 can also be planar or concave, such as... Figure 4 As shown.

[0032] The angle between the inner wall of the slope sidewall 12 or the tangent of the inner wall of the slope sidewall and the bottom surface of the mold is 1-89°. That is, when the inner wall of the slope sidewall is planar, the angle between the inner wall of the slope sidewall and the bottom surface of the mold is 1-89°. When the inner wall of the slope sidewall is convex or concave, the angle between the tangent of the inner wall of the slope sidewall and the bottom surface of the mold is 1-89°.

[0033] The depth of the microneedle cavity in the main body 11 of the microneedle negative mold array is 40-1600μm. The vertical depth of the sloped sidewall 12 is 0.5-10mm.

[0034] The microneedle cavity morphology of the microneedle negative mold array body 11 includes, but is not limited to, conical, pyramidal, spiral, okra-shaped, starfruit-shaped, and platform-reinforced types. The shape of the microneedle mold 1 includes, but is not limited to, square, circular, crescent-shaped, T-shaped, and bone-shaped types.

[0035] The material of the microneedle mold 1 is one of the following: metal, polydimethylsiloxane, polymethyl methacrylate, ceramic, resin, and polylactic acid.

[0036] In this embodiment, the microneedle mold is made of polymethyl methacrylate and is formed by casting a silicon microneedle male mold processed using microelectromechanical technology. The microneedle mold is square in shape, with a vertical depth of 1.5 mm on the sloping sidewalls, an angle of 30° between the tangent of the inner sloping wall and the bottom surface of the mold, and a horizontal width of 3 mm on the sloping sidewalls. The microneedle cavity of the main body of the microneedle female mold array is a reinforced conical platform type, with a platform depth of 200 μm, a cone depth of 400 μm on the platform, and a total depth of 600 μm.

[0037] In use, a measured amount of pre-prepared, de-air-filled molding liquid is added to the microneedle mold 1. The molding liquid is then introduced into the microneedle cavity using methods such as vacuuming or high-pressure spraying. After standing, the molding liquid is dried and cured at below 60°C. After cooling, a silicone gel of appropriate shape and adhesive properties is used as a backing to directly adhere the cured microneedles, allowing the microneedles to be vertically detached from the mold. Because the sidewalls of the microneedle mold 1 are sloping sidewalls 12 (i.e., their inner walls gradually slope outwards from bottom to top), the tension effect during molding liquid curing at the microneedle edges is weakened, resulting in microneedles with smooth edges. This allows for stable adhesion to the backing, facilitating smooth demolding, ensuring demolding efficiency, and guaranteeing the quality of the microneedle product.

[0038] Example 2

[0039] like Figure 5 and 6As shown, this embodiment provides a microneedle mold 1, whose structure is basically the same as that of the microneedle mold 1 in Embodiment 1, except that: four overflow guide ports 121 are provided on the top edge of the sloping sidewall 12, respectively located on the four sides. The overflow guide ports 121 are used for mold liquid overflow, which can further accurately measure the mold liquid during scale-up production. Excess mold liquid injected into the mold overflows from the overflow guide ports 121 and flows into the overflow receiving pool for recycling. Of course, other numbers of overflow guide ports can be set according to needs.

[0040] The use of the microneedle mold 1 is basically the same as that in Example 1, except that: there is no need to pre-quantify the mold liquid; the prepared mold liquid with air bubbles removed can be directly added into the microneedle mold 1, and excess mold liquid can overflow through the overflow guide port 121 to complete the quantification.

[0041] Example 3

[0042] like Figure 7-9 This embodiment provides a microneedle mold kit, including an upper mold cover 2 and a microneedle mold 1 of embodiment 1 or embodiment 2.

[0043] The upper mold cover 2 is a cap-like structure that matches the microneedle mold 1 and can be placed on the microneedle mold 1. The upper mold cover 2 has a through-hole 21 for defining the microneedle shape, and the inner wall of the through-hole 21 is a slope that gradually slopes outward from bottom to top. Figure 8 As shown, when the upper mold cover 2 is placed on the microneedle mold 1, the microneedle shape defining hole 21 is within the range of the microneedle female mold array body 11 of the microneedle mold 1, and the bottom of the microneedle shape defining hole 21 is tightly fitted with the top surface of the microneedle female mold array body 11. The microneedle mold 1 only exposes a portion of the microneedle cavity corresponding to the microneedle shape defining hole 21. After the mold liquid is introduced and solidified, a microneedle with the same shape as the microneedle shape defining hole 21 is formed. The inner wall of the slope of the microneedle shape defining hole 21 is planar, convex, or concave. The inner wall of the slope of the microneedle shape defining hole 21 can weaken the tension effect on the edge of the microneedle during the solidification of the mold liquid.

[0044] In this embodiment, the microneedle shape defining hole is circular to prepare circular microneedles. Of course, the shape of the microneedle shape defining hole can also be set according to the desired shape of the microneedle to be prepared. That is, in the microneedle mold kit, the microneedle mold 1 can be equipped with multiple upper mold covers 2 with microneedle shape defining holes 21 of different shapes to meet the production needs of microneedles of different shapes. Alternatively, multiple microneedle shape defining holes 21 of different shapes can be set on one upper mold cover 2 to also meet the production needs of microneedles of different shapes. The setting of the upper mold cover 2 further improves the utilization efficiency and flexibility of the microneedle mold 1, reduces the number of times the microneedle mold 1 is prepared, thereby saving production costs and improving production efficiency.

[0045] The angle between the inner wall of the beveled surface of the microneedle-shaped limiting hole 21 and the bottom surface of the mold is 1-89°. That is, when the inner wall of the beveled surface is flat, the angle between the inner wall of the beveled surface and the bottom surface of the mold is 1-89°. When the inner wall of the beveled surface is convex or concave, the angle between the tangent of the inner wall of the beveled surface and the bottom surface of the mold is 1-89°.

[0046] The vertical depth of the microneedle-shaped defined hole 21 is 0.6-12mm.

[0047] The material of the upper mold cover 2 is one of the following: metal, polydimethylsiloxane, polymethyl methacrylate, ceramic, resin, and polylactic acid.

[0048] In this embodiment, the upper mold cover is made of polymethyl methacrylate. The angle between the inner wall of the beveled surface of the microneedle-shaped defined hole and the bottom surface of the mold is 30°, and the horizontal width of the inner wall of the beveled surface is 3mm.

[0049] In a preferred embodiment, the upper surface of the upper mold cover 2 is provided with two overflow guide channels 22. One end of the overflow guide channel 22 communicates with the micro-needle-shaped limiting hole 21, and the other end extends to the edge of the upper mold cover 2. The overflow guide channel 22 is used for mold liquid overflow. During scale-up production, the mold liquid can be more accurately metered. Excess mold liquid injected into the mold overflows from the overflow guide channel 22 and flows into the overflow receiving pool for recycling. Of course, other numbers of overflow guide channels can be provided as needed.

[0050] In a preferred embodiment, the bottom of both sides of the upper mold cover 2 is provided with an opening 23, which facilitates its separation from the microneedle mold 1.

[0051] The microneedle mold kit of the present invention can fabricate other microneedle arrays smaller than the cavity area of ​​microneedle mold 1 (microneedle female mold array body 11). In use, as... Figure 8 and 9As shown, the upper mold cover 2, with a specific shaped microneedle shape defining hole 21, is placed on top of the microneedle mold 1 and aligned. The prepared, bubble-free mold liquid is added into the microneedle shape defining hole 21 of the upper mold cover 2. Excess mold liquid overflows through the overflow channel 22, completing the quantitative process. Vacuuming or high-pressure jetting is used to allow the mold liquid to enter the microneedle cavity of the lower microneedle mold 1. Because the bottom of the microneedle shape defining hole 21 is tightly fitted to the top surface of the microneedle negative mold array body 11, the mold liquid only enters the microneedle cavity within the corresponding range of the microneedle shape defining hole 21. After standing, the mold liquid is dried and cured below 60°C. After cooling, a silicone gel of the corresponding shape with adhesive properties is used as a backing to directly adhere the cured microneedles. The microneedles are then vertically detached from the mold, resulting in microneedles of the desired shape consistent with the shape of the microneedle shape defining hole 21. In particular, since the inner wall of the microneedle shape limiting hole 21 of the upper cover plate is a slope that gradually slopes outward from bottom to top, the tension effect can be weakened when the microneedle edge mold liquid is cured, so that the microneedle has a smooth edge, which can be stably bonded to the backing, thereby achieving smooth demolding, ensuring demolding efficiency, and ensuring the quality of microneedle products.

[0052] In this invention, unless otherwise stated, scientific and technical terms used herein have the meanings commonly understood by those skilled in the art. Furthermore, the reagents, materials, and procedures used herein are all widely used in the relevant fields.

[0053] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A microneedle mold kit, characterized in that: Including the upper mold cover and the microneedle mold; The microneedle mold has a microneedle female mold array body and sloping sidewalls surrounding the microneedle female mold array body; the microneedle female mold array body is a platform with several microneedle cavities, which are arranged in an array; the sloping sidewalls are higher than the microneedle female mold array body, and the inner wall of the sloping sidewalls is a slope that gradually slopes outward from bottom to top; the inner wall of the sloping sidewalls is convex or concave. The upper mold cover is a cap-like structure that matches the microneedle mold and can be placed on the microneedle mold. The upper mold cover has a through-hole for defining the shape of the microneedle, and the inner wall of the through-hole is a slope that gradually slopes outward from bottom to top. When the upper mold cover is placed on the microneedle mold, the through-hole is within the range of the microneedle female mold array body of the microneedle mold, and the bottom of the through-hole abuts against the top surface of the microneedle female mold array body. The microneedle mold only exposes a portion of the microneedle cavity corresponding to the through-hole. After the mold liquid is introduced and solidified, microneedles with the same shape as the through-hole are formed. The inner wall of the slope of the through-hole is planar, convex, or concave.

2. The microneedle mold kit according to claim 1, characterized in that: in, The angle between the inner wall of the slope sidewall or the cross-section of the inner wall of the slope sidewall and the bottom surface of the mold is 1-89°.

3. The microneedle mold kit according to claim 1, characterized in that: in, The depth of the microneedle cavity of the main body of the microneedle negative mold array is 40-1600μm; the vertical depth of the slope sidewall is 0.5-10mm.

4. The microneedle mold kit according to claim 1, characterized in that: in, The top edge of the slope sidewall is provided with at least one overflow outlet.

5. The microneedle mold kit according to claim 1, characterized in that: in, The material of the microneedle mold is one of the following: metal, polydimethylsiloxane, polymethyl methacrylate, ceramic, resin, and polylactic acid.

6. The microneedle mold kit according to claim 1, characterized in that: in, The angle between the inner wall of the slope of the microneedle-shaped defined hole or the cross-section of the inner wall of the slope and the bottom surface of the mold is 1-89°.

7. The microneedle mold kit according to claim 1, characterized in that: in, The vertical depth of the microneedle-shaped defined hole is 0.6-12 mm; The material of the upper mold cover is one of the following: metal, polydimethylsiloxane, polymethyl methacrylate, ceramic, resin, and polylactic acid.

8. The microneedle mold kit according to claim 1, characterized in that: in, The upper surface of the upper mold cover is provided with at least one overflow channel, one end of which is connected to a micro-needle shaped limiting hole, and the other end extends to the edge of the upper mold cover.

9. The microneedle mold kit according to claim 1, characterized in that: in, The bottom of at least one side of the upper mold cover is provided with an opening.

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