Method and Device for Producing Microneedles
20220062604 ยท 2022-03-03
Inventors
Cpc classification
B29C2043/3205
PERFORMING OPERATIONS; TRANSPORTING
B29L2031/753
PERFORMING OPERATIONS; TRANSPORTING
B29C2043/026
PERFORMING OPERATIONS; TRANSPORTING
B29C43/021
PERFORMING OPERATIONS; TRANSPORTING
B29C43/36
PERFORMING OPERATIONS; TRANSPORTING
B29C39/24
PERFORMING OPERATIONS; TRANSPORTING
B29C39/026
PERFORMING OPERATIONS; TRANSPORTING
B29L2031/7544
PERFORMING OPERATIONS; TRANSPORTING
International classification
A61M37/00
HUMAN NECESSITIES
B29C39/02
PERFORMING OPERATIONS; TRANSPORTING
B29C39/24
PERFORMING OPERATIONS; TRANSPORTING
Abstract
The present disclosure relates to a method for producing microneedle arrays in a mold, including a plurality of receptacles that taper from an upper base surface to a lower tip surface, where a first component is fed into at least two receptacles through a feed opening that is spaced apart from the base surface, where the receptacles are filled with an additional component from above the feed opening, where the fillings of at least said two receptacles, which fillings are formed of at least the first component and the additional component, are connected to one another above the base surfaces, and where after the first component and the additional component have solidified, the microneedle array comprising the fillings that have solidified to form needles is removed from the mold.
Claims
1. A method for producing microneedle arrays in a mold, comprising providing a mold comprising a plurality of receptacles that taper from an upper base surface to a lower tip surface wherein a first component is fed into at least two receptacles through a feed opening that is spaced apart from the base surface, wherein said at least two receptacles are filled with an additional component from above the feed opening, wherein the fillings of at least said two receptacles, which fillings are formed of at least the first component and the additional component, are connected to one another above the base surfaces, and wherein after the first component and the additional component have solidified, the microneedle array comprising the fillings that have solidified to form needles is removed from the mold.
2. The method according to claim 1, wherein the first component is fed through the tip surfaces.
3. The method according to claim 2, wherein after feeding the first component, at least a plurality of tip surfaces are closed by a subshell that is movable relative to the mold.
4. A device for producing microneedle arrays by means of a method according to claim 1, comprising a mold, wherein the mold comprises a plurality of receptacles that taper from an upper base surface to a lower tip surface, and that each receptacle comprises a feed opening that is spaced apart form the base surface.
5. The device according to claim 4, wherein the feed opening connects the receptacle to a feed chamber forming a reservoir.
6. The device according to claim 4, wherein the surface area of the cross-sectional area of the individual feed opening is smaller than or equal to 0.01 square millimeters.
7. The device according to claim 4, wherein the feed opening of the individual receptacle comprises the tip surface of said receptacle.
8. The device according to claim 7, wherein the tip surfaces lie in a first plane.
9. The device according to claim 7, wherein the tip surfaces are closable.
10. The device according to claim 4, further comprising a compression device that is arranged above the mold.
11. The device according to claim 4, wherein the surfaces of the top surface, the bottom surface and the receptacle of the mold are configured to be non-adhesive in at least some areas.
12. A microneedle array comprising at least two of the needle that taper from a needle connection cross-section to a smallest end surface, wherein the needles are connected to a support strip in the needle cross-section, and the area adjoining the smallest end surface consists of the solidified first component.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
[0015]
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[0030]
[0031] The mold (21) can also consist of several overlying discs that are centered to each other. The individual discs can be joined together in a detachable or non-detachable manner. The receptacles (25) then penetrate several or all discs, for example.
[0032] In the illustrated exemplary embodiment, the individual receptacle (25) has a center line (26) being normal to the top surface (22) and the bottom surface (23). The receptacle (25) tapers in a frustoconical manner from the top surface (22) to the bottom surface (23). The inner shell surface (34) of the receptacle (25) has, for example, a circular cross-section on each point of the center line. The base surface (27) lying in the plane of the top surface (22) as well as the tip surface (28) lying in the plane of the bottom surface (23) of the receptacle (25) are formed in a circular manner, for example. The center line (26) connects the centers of these two circular areas.
[0033] The base surface (27) and/or the tip surface (28) may have a shape differing from the circular form. For example, both surfaces may have a square, triangular, elliptical, etc. cross-section. For example, the wall limiting the individual receptacle (25) then has the shape of a truncated pyramid shell surface, a truncated cone portion differing from the circular truncated cone, etc. A transition, for example from a truncated pyramidal portion to a truncated portion is also possible. The individual receptacle (25) can also comprise a portion adjoining the top surface (22) and having a constant cross-section. For example, said portion can be cylindrical, triangular, square, rectangular, hexagonal, etc.
[0034] The center line (26) can enclose an angle different from the right angle with the top surface (22) and/or the bottom surface (23). The truncated cone is then formed obliquely, for example. It is also possible to arrange the base surface (27) and the tip surface (28) non-parallel to each other. The receptacles (25) can be in alignment, e.g. they can comprise center lines (26) that are parallel to each other.
[0035] In
[0036]
[0037] In this illustration of
[0038] In this example, the filling connection (46) is arranged in the middle of the bottom (42). The filling connection (46) passes through the bottom (42) and connects the feed chamber (51) to the environment (1) in the illustration of
[0039] The mold (21) and the subshell (41) are movable relative to each other, e.g. displaceable. In the exemplary embodiment, they are adjustable to each other in height direction (11). The feed chamber (51) thus has a variable size. In this exemplary embodiment, the volume of the feed chamber (51) is e.g. controllable by the stroke of the subshell (41) relative to the mold (21) in height direction (11). In the illustration of
[0040] The device (10) can also be configured such that the bottom (42) comprises impressed channels (48) on the inside (47), see
[0041] The channels (48) impressed into the inside (47) of the bottom (42) can also formed radially, see
[0042]
[0043] The first component (2) is provided in a container, for example, which is mounted to the filling connection (46) at the bottom side. The first component (2) is conveyed into the feed chamber (51) by applying e.g. an external pressure to the flexibly deformable container, for example. The container can also be under positive pressure. The feed chamber (51) is filled with the first component (2). The first component (2) gets from the feed chamber (51) through feed openings (31) into the receptacles (25). In this exemplary embodiment, the feed openings (31) comprise the tip surfaces (28) of the apertures (25).
[0044] For example, the surface area of the individual tip surfaces (28) corresponds to the cross-sectional area of the respective feed opening (31). Said cross-sectional area is smaller than or equal to 0.01 square millimeters, for example. The feed openings (31) are produced e.g. by laser, by hot stamping, by micro-milling, by injection molding, by lithography, etc. In this exemplary embodiment, each receptacle (25) has exactly one feed opening (31). All receptacles (25) are filled evenly, for example. Any gas inclusions of the first component (2) rise as gas bubbles and leave the receptacles (25) e.g. through the base surfaces (27). For example, all receptacles (25) are only filled up to a partial level. After filling, the filling level of the first component (2) in the receptacles (25) is between the tip surfaces (28) and the base surfaces (27) in height direction (11). For example, the filling level is at one third of the distance of the two mentioned surfaces as measured from the tip surface (28).
[0045] The filling can also be performed such that only individual receptacles (25) of the mold (21) are filled. For example, the feed openings (31) of the other receptacles (25) are e.g. temporarily closed. For example, after said selective filling, the remaining receptacles (25) can remain unfilled or can be filled with another component, e.g. another solution containing an active ingredient. For this purpose, the receptacles (25) that were filled first can then be closed, for example.
[0046] The first component (2) can also be introduced into the receptacles (25) by negative pressure in the environment (1) of the mold (21). For example, the e.g. flowable first component (2) is then sucked out of the container which has a high internal pressure relative to the ambient pressure.
[0047] Masses that are flowable in a limited manner, semi-solid and solid substance mixtures or powder can also be introduced into the receptacles (25), e.g. by mechanical pressure or a dosage. It is also possible to convey the first component (2) by means of the effect of capillary forces through the feed openings (31) into the receptacles (25).
[0048] In the next method step, the feed openings (31) of the receptacles (25) are closed. For this purpose, for example the subshell (41) is displaced relative to the mold (21) in displacement direction (12) until the bottom (42) closes all apertures (25). It is also possible to individually close the feed openings (31) at the bottom surface (23) of the mold (21), to insert a closing plate, to actuate flaps that are hinged via joints, etc. It is also possible to use a pivotable closing plate.
[0049] In
[0050] Then, the first e.g. liquid component (2) is solidified by drying, for example.
[0051] The bottom surface (23) of the mold (21) remains closed, the top surface (22) remains open. Drying can be performed at a constant or increased temperature of the environment (1). During drying, evaporation reduces both the mass and the volume of the first component (2) in the receptacles (25). The first component (2) solidifies.
[0052] It is also possible to solidify and then optionally dry the first component (2) by a reaction e.g. chemical, thermal, pulse-induced or radiation-induced reaction. Optionally, the method step for solidification of the first component (2) may be omitted.
[0053]
[0054] The shell surface (65) of the tips (62) is regularly formed in the area adjoining the smallest end surface (63), for example. The shell surface (65) is in full contact with the delimiting surface of the receptacles (25), for example. In the area of the tip (62) adjoining the largest end surface (64), the shell surface (65) can detach from the inner wall of the individual receptacle (25) due to shrinkage upon drying. After drying, the tips (62) are formed in a solid manner.
[0055] In a further method step, an additional, e.g. second component (3), e.g. a fill mass, is introduced into the mold (21) and applied to the mold (21), see
[0056] The additional component (3) applied to the mold (21) is processed by a compression device (4) in the form of a roller (4), for example. Here, the roller (4) rolls off on the mold (21) and/or on the additional component (3). The additional component (3) is pressed into the receptacle (25). During further overrolling, the second component (3) is solidified both in the receptacles (25) and on the top surface (22) of the mold (21). The second component (3) is pressed in the receptacles (25) onto the respective largest end surface (64) of the individual tips (62). In this joining process, the additional component (3) bonds adhesively to the tips (62), for example. Optionally, an adhesive portion in the additional component (3) can strengthen the join between the additional component (3) and the tips (62). Thus, the fillings (8) of the receptacles (25) each consist of at least the first component (2) and the additional component (3). The additional component (3) is further compressed, e.g. by rolling, wherein the entire additional component (3) is further solidified. The additional component (3) now consists of a support strip (71), e.g. a support plate (71) and conical needle stumps (72). A tip (62) is seated on each needle stump (72). The additional component (3) and the tips (62) are solid and joined together. Respectively one needle stump (72) is connected to one tip (62). Together with the support strip (71) they form a microneedle array (61).
[0057] The additional component (3) can already be introduced into the receptacles (25) when being applied to the mold (21). This can be done by casting, injecting, spreading, rolling, etc. Furthermore, stamps be used to solidify the additional component (3). It is also possible to dry the additional component (3) for solidification. Moreover, combinations of the specified methods are possible.
[0058] The additional component (3) can also be conveyed into the receptacle (25) directly after the introduction of the first component (2) or simultaneously with the introduction of the first component (2). In this case, there is no separate solidification or drying of the first component (2), for example.
[0059] The application of more than two components is also possible. Here, the needle stumps (72) can consist of the additional component (3), for example. The support strip (71) is then a ribbon joined with the needle stumps (72), for example.
[0060] After solidification of the additional component (3), the microneedle array (61) can be removed from the mold (21).
[0061] In the exemplary embodiment, the support strip (71) is formed as a disc having a circular cross-section. The support strip (71) projects beyond the envelope contour of the needle (73) in the needle connection cross-section (75). Regardless of the design of the mentioned envelope contour of the needle (73), the support strip (71) can comprise a circular, elliptical, rectangular, triangular, etc. cross-section in a plane normal to the longitudinal direction of the needles (73).
[0062] The individual needles (73) of the solidified fillings (8) can first also be produced without connection through the support strip (71). In order to remove the needles (73) from the receptacles (25), a support strip (71) is then connected to the needles (73), for example. For this purpose, the support strip (71) is joined adhesively with the needles (73) at the needle connection cross-section (75), for example. The support strip (71) can be configured as a support plate, a support layer, e.g. as a polymeric adhesive film, as an adhesive tape, etc. In this case, the microneedle array (61) removed from the device (10) consists of at least two needles (73) and the support strip (71).
[0063] After removal of the microneedle array (61) from the device (10), the latter can be re-used, for example. After cleaning the device (10), a further microneedle array (61) is produced by means of said device (10), for example. This repeated production is performed as described above.
[0064] In
[0065]
[0066] It is also possible to produce the needle tips (62) as well as the needle base or needle butts and the support strip (71) of soluble components or substance mixtures.
[0067] Alternatively, it is also possible to produce the needle tips (62), the needle base, and the support strip (71) of insoluble components or substance mixtures. For example, one or several substances included for therapeutic and/or diagnostic application are delivered to the surrounding skin layer after swelling with moisture absorption.
[0068] The needle tips (62) can also consist of a less rapidly soluble component, while the needle base and support plate (71) consist of a rapidly soluble component. This leads to a change in the release rate of active ingredients from the respective component.
[0069] In case of a device (10) with a lateral filling of active ingredient, the subshell (41) illustrated in
[0070]
[0071] Adhesion can be reduced by a coating (13) of the mentioned surfaces, by application of a release agent and/or by mechanical processing of the surfaces. In this respect, the applied methods and coating materials and/or release agents may vary. The surfaces that only come into contact with the additional component (3) may be treated differently than the surfaces that only come into contact with the material of the tips (62) during production of the microneedle array (61).
[0072] In case of a coating (13) of the surfaces, the coating (13) can consist of polytetrafluorethylene, polyethylene, polypropylene, etc. For example, a polysorbate or another oily release agent can be used as a release agent applied to the mentioned surfaces.
[0073] If the surfaces are treated mechanically, the surface roughness can be reduced, e.g. by electropolishing, corona treatment, laser polishing, etc. All these measures reduce losses during dosage of the microneedle array (61) and facilitate damage-free removal of the microneedle array (61) from the mold (21).
[0074]
[0075] Feed openings (31) open into the inner shell surfaces (34) of the receptacles (25). The feed openings (31) are located below the base surfaces (27). For example, the feed openings (31) are arranged, starting from the tip surfaces (28), in the lower half of the height of the receptacles (25) in height direction (11). An arrangement in the lower third or in the lower fifth of the height is also possible. The cross-section of the individual feed opening (31) corresponds to the surface of the individual tip surface (28), for example.
[0076] The feed openings (31) are connected by feed channels (32) to feed connections (33) accessible from the outside of the mold (21). For example, a reservoir, which is not illustrated here, is connected to the feed connections (33). For example, said reservoir is configured as explained in connection with the previously described exemplary embodiments. The net of e.g. intersecting feed channels (32) forms a feed chamber (51), for example. It is also possible to arrange all feed connections (33) on an exterior of the mold (21).
[0077]
[0078] After connecting the mold (21) to the reservoir, the first component (2) flows through the feed channels (32) into the receptacles (25). Due to the receptacles (25) communicating with each other, all receptacles (25) are filled to the same level. For example, when the first component (2) is filled without pressure, the filling level of the receptacles (25) lies within the cross-sectional area of the feed openings (31) and the feed channels (32) aligned therewith. The first component (2) can be solidified separately. For this purpose, the connection of the first component (2) to the feed opening (31) is separated, for example. The remaining liquid stock from the feed chamber (51) flows along the feed channels (32) into the receptacles (25). The feed channels (32) are emptied, for example.
[0079] The second component (3) is filled into the receptacles (25) as described above. For example, the additional component (3) and the support strip (71) are then solidified. In this exemplary embodiment, the fillings (8) can also be solidified together. It is also possible to affix the support strip (71) onto the needles (73) after the fillings (8) have solidified, or to connect the support strip (71) to the needles (73) in a form-fitting or materially bonded manner.
[0080] In this exemplary embodiment, the additional component (3) can also be fed through filling openings of the inner shell surfaces (34) of the receptacles (25), wherein the filling openings are located in height direction (11) between the feed openings (31) and the base surfaces (27).
[0081] For example, the several jointly produced microneedle arrays (61) are removed from the mold (21) as described above. In doing so, remaining connection between the fillings (8) and the feed channels (32) can be separated, if necessary. The mold (21) can be used as a reusable or as a disposable mold (21), e.g. as a dead mold (21).
[0082] The individual microneedle arrays (61) are applied as described above.
[0083] The specified exemplary embodiments can also be combined with each other.