Microneedle device, patch, applicator and method

Abstract

The invention relates to a microneedle device comprising a support base and at least one microneedle. The support base defines a top surface from which the at least one microneedle projects upwards. The microneedle device further comprises a barrier structure extending substantially around a lower end of the microneedle. Further, the barrier structure is arranged for substantially counteracting to at least a certain extent that during at least a certain period of pre-loading the microneedle device with a certain substance, at least a substantial portion of a film of a liquid product comprising said substance can flow out over the top surface of the support base when said film of liquid product slides down along an outer surface of the microneedle to a certain extent.

Description

[0001] Title: Microneedle device, patch, applicator and method

[0002] The invention relates to a microneedle device. The microneedle device, which may comprise at least one and preferably multiple microneedles, each of which microneedles may have length below 1 mm, may be arranged and / or suitable for instance for administer a substance, for example a vaccine, a drug or another agent. Alternatively or additionally, the microneedle device may be arranged and / or suitable for taking a sample, for instance a blood sample or the like.

[0003] Over the recent decades microneedle devices and their use have become more and more popular, for example as their use, in particular in contrast to the use of traditional hypodermic needles or the like, is relatively comfortable for patients, for instance as their use will usually be a lot less painful. Besides, microneedle devices have also all kinds of other advantages. For example, discarded used microneedle may form less hazardous waste than discarded used hypodermic needles. Another example of an advantage of microneedles may lie in that microneedle devices may be relatively cost efficient to produce in comparison with hypodermic needles, for example as a microneedle device for administering a drug may require less material and / or relatively cheap materials compared to a hypodermic needle for administering the same drug.

[0004] Microneedle devices usually comprise a multiplicity of microneedles of a suitable geometry projecting as an out of plane structure from a base support. The microneedles are usually arranged in an array, which for instance may comprise only a few microneedles, tens of microneedles or several hundreds of microneedles or even more.

[0005] There are all kinds of microneedle devices, such as arrays with solid needles, which may for instance be substantially cone-shaped, substantially bullet-shaped or substantially obelisk-shaped.

[0006] Another type of microneedle devices comprises hollow microneedles which are connected to reservoirs which are loaded or so-called pre-loaded with for instance a drug or the like. Disadvantages of such known microneedle devices may include that their microneedles may become clogged, for example due to excessive swelling, and that the hollow microneedles may buckle under pressure, both of which may cause that too little of the drug will be actually delivered to a patient. Yet another type of microneedle devices comprises microneedles which are pre-loaded by coating them and / or by letting them absorb a drug or other substance or agent. For the latter, the microneedles may be porous to a certain extent. Often, the coated and / or at least partly impregnated microneedles of such pre-loaded microneedle devices are also treated with, in particular covered with, other surfactants or thickening agents or the like to facilitate a relatively proper delivery of the drug or other substance or agent with which it is provided.

[0007] It is noted that usually, the coating or other pre-load will initially be applied to the microneedle device as a liquid product and will be allowed to dry up, by letting a solvent evaporate, such as to form a solid pre-loaded payload, for instance in the form of a solid film or the like. Once the coated and / or more or less impregnated microneedles of the microneedle device are inserted into a patient, in particular for instance inserted into the skin, the pre-loaded payload may dissolve and thus become administered to the patient.

[0008] The microneedles of such a pre-loaded microneedle device are often made of polymers or metals. However, other materials are possible as well, such as for example ceramic materials or the like, in particular in order to form more or less porous microneedles, which may advantageous for purposes in which it desired that the microneedles can absorb at least a certain amount of substance or compound.

[0009] There are different methods for pre-loading such microneedle devices. For example, the microneedle devices can be loaded by dipping, inkjet loading, immersion loading, drop loading or spay loading. Each of these pre-loading methods may have their respective drawbacks or disadvantages.

[0010] For example, by immersion loading, the entire microneedle device, thus a device comprising not only a multiplicity of microneedles but also comprising a support base on which the microneedles are located, is immersed into a solution comprising the drug or other substance or compound with which the microneedles are to be loaded. Although this may be a relatively simple method, it can be considered a huge drawback that relatively much drug or compound may be wasted as usually none of the drug or compound delivered to the support base will be used, as it will usually not end up within the patient but will stay simply behind at the support base which itself does not penetrate into the patient. Drop loading may be slightly less wasteful, as then only the top surface of the microneedle device is treated by disposing one or more drops thereon. Although no drug or compound may be wasted on the back face of the support base, still relatively much drug or compound may end up between the microneedles on the top surface of the support base.

[0011] The same may apply to spray loading, in which a top surface of the microneedle device is sprayed in order to become pre-loaded. Although less drug or compound may be used to cover the top side of the microneedle device, relatively much of the drug or compound may still end up between the microneedles.

[0012] Dip loading may be more efficient. In such dip loading methods, the microneedles are dipped, when they point downwards, into a liquid. In order to counteract that liquid may touch the support base, in certain types of dip loading, a relatively thin bath or film of liquid product may be provided in order to counteract that the microneedle device will be entered to deep therein, thereby counteracting that the support base would touch the liquid product and would unintentionally be provided with the substance or the like. In other types of dip loading, a mask may be provided through which the microneedles extend. Said mask may then counteract that the support base would be unintentionally loaded with the substance.

[0013] It is noted that once the microneedles have been dipped into the liquid product, the microneedle device may be turned upside down to the position in which the microneedles protrude upwards from the support base. This may for instance be advantageously to counteract that too much of the liquid product can drip off from the microneedles before it is dried up. Additionally, or alternatively, turning around the device after dipping the microneedles into the liquid product may counteract that relatively much of the liquid, e.g. in the form of a micro-drop, may stick to the tip of the microneedle, and would result in relatively much deposition of drug or other substance or compound on the tip, which for instance could be highly undesirable as it could lead to far less sharp microneedles.

[0014] Although dip loading may be relatively efficient and far less wasteful than drop loading and dip loading, another disadvantage of dip loading may lie in that lower ends of the microneedles may not become properly loaded, for instance as the device is not dipped far enough into the liquid product and / or because it is prevented by the mask, if any. On the other hand, when the dipped microneedle device has been turned around such as to let the microneedles point up during drying, the then still relatively fluid liquid product may sag and slide down along the microneedle and on to the support base. This may also lead to a relatively large waste of substance, which is highly undesirable.

[0015] Inkjet loading may be considered to be more or less comparable with inkjet printing. In such inkjet loading methods, relatively tiny droplets may be ejected from nozzles, in particular piezo-driven nozzles. The inkjet loading methods may be relatively precise compared to other methods. As such, they may for example relatively effectively counteract wastage of a drug or other compound to be loaded onto the microneedle device. However, a first disadvantage of such inkjet loading method may lie in that the nozzle can only apply drug or other substance or compound to one lateral side of one microneedle at a time. Loading all microneedles and loading all sides of the microneedles may take relatively much time. Although it may be possible to use multiple nozzles simultaneously, this may be difficult, in particular if the microneedle spacing is relatively small. In addition to, or alternative to, that inkjet loading may be relatively time consuming, it may also be a relatively expensive method and / or a relatively error-prone method, for instance as nozzles may easily clog, in particular when the liquid product has a relatively high viscosity. On the other hand, when the liquid product has a relatively low viscosity, the liquid product may relatively easily slide or run down along the microneedles and may flow out over the top surface of the support base, thereby again leading to wastage of the drug or substance or the like.

[0016] As such, there may be a need for an alternative method for loading or so-called pre-loading a microneedle device and / or a need for an alternative microneedle device.

[0017] It is an object of the invention to provide an alternative microneedle device and / or an alternative method of pre-loading a microneedle device. In particular, it can be an object of the invention to provide a microneedle device and / or a method of pre-loading a microneedle device, wherein at least one disadvantage of a prior art microneedle device and / or a prior art method of pre-loading a microneedle device is counteracted. More in particular, the invention may aim to provide a microneedle device and / or a method of pre-loading a microneedle device, wherein at least one of the disadvantages mentioned above is counteracted. In embodiments, the invention aims at providing a method of pre-loading a microneedle device, which at the one hand can be relatively simple and / or relatively fast, and which on the other hand may be relatively cost-effective, and in particular relatively little wasteful. In embodiments, the invention aims at providing an alternative microneedle device which may be arranged for enabling that it can on the one hand be pre-loaded in a relatively simple and / or relatively fast manner, while it on the other hand can also enable that the pre-loading can be relatively cost-effective, and in particular relatively little wasteful.

[0018] Thereto, in a first aspect, the invention provides for a method of pre-loading a microneedle device, wherein said method comprises the steps of providing a microneedle device; and applying a liquid product to the at least one microneedle, for instance by means of dipping the at least one microneedle into the liquid product or for instance by means of inkjet loading, dispensing or spraying or the like, wherein at least a part of the applied liquid product forms a substantially liquid film at an outer surface of the microneedle; and allowing the applied liquid product to harden, for example dry up, to at least a certain extent, while a barrier element, which is part of the microneedle device itself and which extends substantially around a lower end of the microneedle, counteracts to at least a certain extent that at least a part of a lower portion of said initially substantially liquid film can slide or flow away substantially beyond said barrier structure, preferably at least partly by supporting said lower portion of the film at least partly on top of a substantially laterally extending support surface of the barrier structure. When the applied liquid product is allowed to harden to at least a certain extent, it can for instance be allowed to dry up to at least a certain extent. Although the liquid may substantially completely dry up, which for example may result in that the microneedle may be provided with a substantially completely dry vaccine or another substantially completely dry substance, the liquid may alternatively stay liquid to a certain extent after it is dried up to a certain extent. In particular, in certain embodiments, the applied liquid product may for example be allowed to dry up such as to result for instance in a still somewhat liquid paste or the like, which may be relatively viscous and / or relatively thick, preferably a still somewhat liquid paste which is stable to at least a certain extent, such that it will not substantially sag or run along the surface of the microneedle.

[0019] It is noted that in the context of the present disclosure the terms loading and pre-loading can be used interchangeably. In particular, in the context of the present disclosure the term pre-loading is considered to mean that the microneedle device is loaded with a certain substance prior to using said microneedle device, thus for instance prior to introducing its one or more microneedles into human or animal tissue.

[0020] The invention also provides for a microneedle device comprising a support base and at least one microneedle, preferably multiple microneedles, wherein the support base defines a top surface, and wherein the at least one microneedle projects upwards from said top surface of the support base, wherein the microneedle device further comprises a barrier structure extending substantially around a lower end of the microneedle, wherein said barrier structure is arranged for substantially counteracting to at least a certain extent that during at least a certain period of pre-loading the microneedle device with a certain substance, at least a substantial portion of a film of a liquid product comprising said substance can flow out over the top surface of the support base when said film of liquid product sags or slides down along an outer surface of the microneedle to a certain extent.

[0021] By providing said barrier structure, it can thus be counteracted in a relatively elegant and / or relatively effective and / or relatively efficient manner that a substantial portion of product, in particular a drug or another so-called substance or a so-called compound, applied to the microneedle may, when it is still relatively fluid to a certain extent, can at the lower end of the microneedle move away from said microneedle and flow out over a part of the top surface of the support base.

[0022] In an embodiment of the microneedle device and / or in an embodiment of the method, the barrier structure may comprise and / or may be formed as a flange extending around the lower end of the microneedle. Said flange may be considered to form a ring or a ledge or ridge, which connects to the lower end of the microneedle. Additionally or alternatively, a border or outer edge of the flange may be substantially offset, in particular over a substantially constant or substantially similar distance, from an outer edge or outskirt of the lower end of the microneedle. In particular, the microneedle may be placed on a raised platform, so to speak.

[0023] It is noted that an upper surface of said flange can define a support surface for supporting thereon a lower end of the film of liquid product, while the flange can then further define a substantially upwardly extending side surface connecting with the upper surface at its upper end, which side surface may preferably connect to the top surface of the support base at its lower end. In particular in cases in which the upper surface is relatively small, for instance when the flange has a relatively low offset distance with respect to the local portion of the microneedle, not much drug or compound or substance or the like can be deposited onto said surface thereby counteracting that relatively much of it could unintentionally be absorbed within the material of said flange of the barrier structure, if said material would be porous and suitable for absorption. Besides, it has been found that, in particular in case a connection between the upper surface and the side surface is relatively sharp, for instance having a relatively small rounding, such as having a rounding radius of less than 5 pm or less than 3 pm, preferably less than 1 pm, more preferably less than 0.5 pm, yet more preferably less than 0.25 pm, still relatively fluid liquid product sliding down along the microneedle may to a certain extent flow onto said upper surface, but may nevertheless be prevented, at least to a certain extent, from flowing over the distal end of the top surface onto the side surface of the flange.

[0024] In particular, a combination of surface tension, caused by cohesion within the film of liquid product, and adhesive forces between the liquid product and the top surface of the barrier structure may overcome the force applied by gravity and may counteract that liquid product flows down along a side surface of the barrier structure. As such, a relatively simple and / or elegant barrier structure may be formed.

[0025] In alternative embodiments, the barrier structure may be formed by a ring or a wall-like structure or the like which is laterally spaced apart from the lower end of the microneedle. The barrier structure may then thus comprise a depression, such as a groove or a gutter or the like. It is noted that the wall-like structure or the like does not need to be free of openings, and could in embodiments for example also be formed as row of upwardly extending protrusions which together surround the lower end of the microneedle, in particular in case the respective spaces between two respective adjacent protrusions are relatively tiny and not large enough to allow the liquid product to flow through a respective opening between said two adjacent protrusions.

[0026] It is for instance also feasible to refrain from such a ring or wall-like structure or the like, but provide the depression into the top surface of the support base. Also in such embodiments, the barrier structure may then thus comprise a depression, such as a groove or a gutter or the like.

[0027] The upwardly extending surface, or upwardly extending surfaces, for instance in case of multiple adjacent protrusions, may block the lower end of the film of liquid material and may counteract that it would flow any further in lateral direction. Hence, said one or more upwardly extending surfaces may thus counteract that the liquid material flows out over the top surface of the support base.

[0028] It is noted that the microneedle device may in particular be arranged for introducing a certain substance or a so-called compound or a so-called agent into a patient or the like, in particular by having the one or more microneedles enter human tissue or animal tissue, for example be skin. Alternatively, the microneedle may be used for intraocular, vaginal, transungual, cardiovascular, vascular, gastrointestinal or intracochlear delivery of the substance. The delivery of the substance may for instance be done in order to administer the substance to a patient. Alternatively, it may be for instance be done in order to use the substance to take a sample, such as for example a blood sample, from the human or animal body. It is noted that the microneedle devices according to the present invention are thus not limited to microneedle devices for intradermal substance delivery or intradermal retraction of sample liquids such as blood etc.

[0029] Advantageously, the microneedle may be pre-loaded, for example it may be at last partly coated, with a substance or a so-called compound or a so-called agent. Said drug or compound or the like may for example be or comprise a vaccine, a drug or another agent, for example an agent or substance forming a cosmeceutical. For example in case the microneedle device is to be used for sampling, its one or multiple microneedles may be pre-loaded with a substance or compound or agent for facilitating sampling, for example by using a compound or agent which may be arranged for binding to a certain element or biological body fluid or the like.

[0030] However, in particular in case the microneedle device is for taking a sample, it may also be possible that it, and thus its one or multiple microneedles, is not pre-loaded with any substance or compound or the like. For example in such embodiments, the one or multiple microneedles may be porous, in particular nano-porous, and / or may be provided with an outer surface arranged for allowing a sample fluid or the like to stick thereon relatively well. For example, said outer surface of the microneedle may be provided with a relatively rough or not smooth, for example substantially dimpled or substantially puckered, outer surface. In case the microneedle device is porous, or in case at least one or multiple microneedles thereof are porous, the microneedle may comprise an interconnected network of pores. It is noted that the barrier structure may also be advantageously applied in an embodiment of a microneedle device of which the one or multiple microneedles are not pre-loaded with, and may thus be substantially free of, any substance or compound to be introduced into a human or animal body or the like. For example, in case the one or multiple microneedles are porous to at least a certain extent and / or their outer surface is arranged for attaching, e.g. sticking, to a body fluid or other fluid to be sampled, the barrier structure may also be advantageous. For example, after the sample has been sampled and the one or more microneedles are retracted from the body from which the sample is sampled, the sample may still be relatively fluid. For example to counteract that the fluid may drip off from the microneedle, the microneedle device may be positioned such that the one or more microneedles point in a substantially upward direction. It will be appreciated that if the sampled liquid is still relatively fluid, it may run, sag, slide or flow downwards. The barrier structure may then counteract, at least to a certain extent, that said liquid may flow out over the top surface of the support base of the microneedle device. The barrier structure can thus counteract that the sample may unintentionally spread out over a relatively large part of the microneedle device. Hence, also in non-pre-loaded embodiments of the microneedle device, the barrier structure may be advantageously applied.

[0031] The invention, in further aspects, also relates to microneedle device having a specific microneedle design.

[0032] In a particular aspect according to the invention, the microneedle device comprises a support base and at least one microneedle, wherein the support base defines a top surface and the at least one microneedle projects upwards from said top surface, wherein the microneedle has a shape which is partly defined by a substantially cylindrical shape, preferably a substantially round cylindrical shape, which at its upper end is provided with two bevels which connect to each other at a cutting edge which is oblique with respect to a central axis of the substantially cylindrical shape, said cutting edge ending in a tip defining a distal end of the microneedle, and wherein the shape of the microneedle is further formed by a cavity which protrudes into the microneedle from its upper end in a downward direction towards a proximal end of the microneedle. Preferably, the cavity may extend downward over at least 50%, more preferably at least 75%, yet more preferably at least 90% of the length of the microneedle. It is noted that although the cross-section of the cavity, transverse to the length of the microneedle, may be substantially constant along the length of microneedle, this is not necessary. For example, at the bottom of the cavity, the cavity may be rounded,

[0033] Due to the cavity, the combined surface area of the microneedle, which may include the surface area of the surface of the cavity and the surface area formed by the outer wall of the substantially cylindrical shape of the microneedle, or at least the remaining portion of the outer wall of the substantially cylindrical base shape of the microneedle, may be relatively large. An advantage of such relatively large combined surface area may for instance lie in that the microneedle may as such provide a relatively high loading capacity, for instance a relatively high loading capacity of small-molecular fluids to be pre-loaded. Regarding relatively large molecules and / or relatively viscous liquids, which could alternatively be loaded, the relatively large combined surface area may also be significantly advantageous in view of loading, in particular in terms of volume and / or a relatively precise positioning.

[0034] Additionally or alternatively, an advantage of the microneedle comprising such cavity may lie in that the cavity can also provide a reservoir, in particular one with a relatively large volume, for uptake of a liquid, which liquid may then be held there, and which subsequently may be absorbed at least partly into the microneedle and / or which may at least partly solidify on the microneedle, for instance as sugar crystals, and / or which may at least partly dry up as part of a coating or a coating layer on the microneedle. For instance in addition to providing additional surface area, the cavity may thus provide a reservoir volume which can allow for relatively large quantities of liquid and / or substance to be applied per loading step, e.g. per dip or print step, for instance in case the loading step is repeated, preferably repeated multiple times, in order to provide relatively much substance in, on and / or at the microneedle.

[0035] Additionally or alternatively, an advantage of the microneedle comprising such cavity may lie in a relatively good piercing ability, which for instance may be due the connections between the cavity and the bevels forming additional cutting edges, which may facilitate that a relatively low force may be required to have the microneedle pierce for instance skin or other tissue.

[0036] In a preferred embodiment, the cavity can extend through a lateral side of the substantially cylindrical shape which partly defines the shape of the microneedle, and, when seen from above, the cavity can then extend through a lateral side of the substantially cylindrical shape located substantially opposite to the lateral side at which the tip is located, such that the resulting shape of the microneedle, at least over as certain extent of its length, can, when seen from above, be substantially C-shaped. The microneedle can then thus have a substantially shovel-shaped design.

[0037] Alternatively, when seen from above, the cavity can be enclosed by an outer wall of the microneedle, in particular such that, when seen from above, said cavity extends over both bevels, thereby splitting up the cutting edge in two separate cutting edge sections, wherein a lower one of said two separate cutting edge sections defines a second tip. An advantage of such design may lie in that the microneedle may then thus comprise two tips, which may facilitate to provide a relatively good piercing ability of the microneedle. Besides, also in such embodiments, the connections between the bevels and respective upwardly extending wall portions defining the cavity may form additional cutting edges, which may provide for a relatively good piercing ability.

[0038] The invention further relates to an applicator, for instance a stamping device, provided a microneedle device.

[0039] The invention further relates to a microneedle patch including a microneedle device.

[0040] A further aspect of the present disclosure relates to a method of manufacturing a multiplicity of microneedles arranged in an array, in particular a ceramic microneedle array, more in particular a patch including such microneedle array, i.e. a ceramic microneedle array patch (MAP). It is noted that the ceramic microneedle array may be made of and / or comprises a ceramic material or a polymer-ceramic composite. Said method comprises providing a green body for a ceramic microneedle array patch comprising multiple microneedles, e.g. at least ten microneedles, preferably at least twenty microneedles, such as at least fifty microneedles or at least a hundred microneedles, for instance several hundreds or even more than a thousand, wherein the microneedles projects upwards from a top surface of a support base, which may be in the form of a backplate. Said method further comprises a step of providing a support plate or a so-called substrate or substrate plate, in particular a flat heat- resistant support plate, and placing the green body on top of the support plate, in particular in a position with its microneedles facing upwards, and providing a weight on top of the green body for fixing the green body at least during a portion of a sintering step. The method also comprises a step of sintering the green body into a ceramic microneedle array, while keeping the weight in place, in particular at least during a substantial period of time. In embodiments, the weight may be formed at least partly by one or more further green bodies, in particular green bodies for similar ceramic microneedle arrays. An advantage of using one or more green ceramic microneedle arrays as a weight may lie in that they may run through a similar shrinkage procedure or substantially the same shrinkage procedure during sintering. Alternatively or additionally, one or more already sintered ceramic microneedle arrays may be used as weight. An advantage thereof may lie in that the weight can be kept relatively consistent during the sintering step, as for example it may be counteracted that the weight loses mass, for instance due to decomposition of organic additives. Additionally or alternatively, an advantage may lie in that, for example contrary to using another green body as a weight, an already sintered ceramic microneedle array will not warp or deform relatively easily. Using such or any other suitable weight during sintering of a green ceramic microneedle array, in particular one comprising or being a microneedle device as discussed above and / or below, may achieve that, in particular after sintering and / or cooling, the tips of multiple microneedles may lie substantially flush with each other in a single plane, in particular a flat plane. In other words, it may facilitate providing a ceramic microneedle array with a relatively uniform needle tip plane. This may for example be beneficial for a drug or other substance loading procedure and / or for the application of a drug, vaccine, another agent or compound or other substance, for example an agent or substance forming a cosmeceutical or the like, into the skin of a human or animal. It will be appreciated that although this method of manufacturing a multiplicity of microneedles arranged in an array may be utilized particularly advantageously with embodiments of microneedle devices according to one or more other aspects and / or embodiments of the present disclosure, said method may also be advantageous for manufacturing one or more other multiplicities of microneedles arranged in an array, in particular a ceramic microneedle array, more in particular a patch including such microneedle array, i.e. a ceramic microneedle array patch (MAP).

[0041] Advantageous embodiments according to aspects of the invention are described in the appended claims.

[0042] By way of non-limiting examples only, embodiments of the present invention will now be described with reference to the accompanying figures in which: Fig. 1A shows a schematic perspective view of a first embodiment of a microneedle device according to the invention;

[0043] Fig. 1 B shows a schematic perspective view of a detail of the microneedle device of Fig. 1 ;

[0044] Fig. 1C shows a schematic cross-sectional detail of a microneedle and a barrier structure on a support base of the microneedle device shown of Figs. 1A and 1 B;

[0045] Figs. 2A - 2B show two schematic cross-sectional details of two further embodiments of a microneedle device;

[0046] Figs. 3A - 3C show three schematic views of details of a fourth embodiment of a microneedle device according to the invention;

[0047] Fig. 4 shows a schematic perspective view of a detail of a fifth embodiment of a microneedle device according to the invention;

[0048] Figs. 5A - 5B show two schematic views of details of a sixth embodiment of a microneedle device according to the invention; and

[0049] Figs. 6A - 6C show three schematic views of details of a seventh embodiment of a microneedle device according to the invention.

[0050] Figure 1A shows an embodiment of a microneedle device 100. Here, the microneedle device 100 is formed as a microneedle array 110. As can be seen here in Figure 1 , the microneedle device 100 may comprise a multiplicity of microneedles 300. Although the exemplary embodiment shown in Figure 1A comprises one hundred and twenty one microneedles 300, the microneedle device 100 may comprise another number of microneedles 300, such as for example one, but preferably multiple microneedles, such as for example tens or hundreds of microneedles 300 or even more than a thousand.

[0051] The microneedle device 100 further comprises a support base 200 for supporting the one or multiple microneedles 300. Actually, the one or multiple microneedle 300 projects upwards from a top surface 210 of the support base 200, as can be seen relatively well in Figures 1 A and 1 B.

[0052] The microneedle 300 may have any suitable shape or form. For example, the shape or form of the microneedle 300 may be substantially cone-shaped, substantially obelisk-shaped or a substantially bullet-shaped. In the exemplary embodiment shown in Figures 1A - 1 C, the microneedle 300 is substantially shaped as a round cylinder cut off with two oblique surfaces 331 , 332 which define a cutting edge 334 ending in a tip 333. Said tip 333 may form the first portion of the microneedle 300 to pierce skin or tissue or the like during use of the device 100. Although the microneedle 300 is here of a solid design, which does not mean that the material may not be porous within such a solid design, the design may in alternative embodiments comprise one or multiple recesses or coves or the like, as for instance is the case in the exemplary embodiments shown in Figures 3A - 6C. Such alternative embodiments will be elucidated below and may be advantageous, for instance in order to provide for a relatively large outer surface area of the microneedle 300, which also will be further elucidated below.

[0053] In embodiments, the microneedle device 100 may be arranged and / or suitable for the administration of a vaccine, a drug or another agent or compound or other substance, for example an agent or substance forming a cosmeceutical or the like. Advantageously, the one or multiple microneedles 300 may be pre-loaded, for instance at least partly coated and / or at least partly impregnated, the latter for instance in cases in which the microneedle 300 is at least partially porous, in particular nano-porous.

[0054] Alternatively or additionally, the microneedle device 100 may be arranged and / or suitable for taking a sample, for instance a blood sample or the like. Thereto the microneedle 300 may for instance be at least partially porous and / or may be provided with a substance or compound or the like which may facilitate binding material to be sampled to said substance or compound and / or to the microneedle 300.

[0055] Advantageously, the microneedle 300 may have a height or length H300 in the range of 100 pm to 2,000 pm, preferably in the range of 250 pm to 1 ,000 pm, for instance in the range of 400 pm to 800 pm, such as for instance about 600 pm, wherein said height H300 of the microneedle 300 is measured from the top surface 210 of the support base 200 to the tip 333 of the microneedle 300 in a direction transverse to said top surface 210.

[0056] Additionally, or alternatively, the microneedle 300 may have a width W310, in particular a widest width W310”, which in embodiments may be formed the diameter of the microneedle or the diameter of the main shape of the microneedle, if any, which is in the range of 20 pm to 800 pm, preferably in the range of 25 pm to 600 pm, for instance in the range of 100 pm to 500 pm, such as for instance about 350 pm.

[0057] According to an aspect of the invention, the microneedle device 100 can further comprise a barrier structure 400. The barrier structure 400 can extend substantially around a lower end 310 of the microneedle 300, which for instance can be seen relatively well in Figures I B and 1C.

[0058] Advantageously, the microneedle device 100 can comprise at least one multiplicity, in particular an array, of microneedles 300, wherein each of the microneedles 300 of said multiplicity is provided with a respective barrier structure 400.

[0059] Said barrier structure 300 can then be arranged for substantially counteracting to at least a certain extent that during at least a certain period of pre-loading the microneedle device 100 with a certain substance, at least a substantial portion of a film 511 of a liquid product 500 comprising said substance can flow out over the top surface 210 of the support base 200 when said film 511 of liquid product 500 slides down along an outer surface 320 of the microneedle 300 to a certain extent, as is shown in the schematic cross-sectional views shown in Figures 1 C, 2A and 2B.

[0060] It is noted that the barrier structure 400 can be arranged such that, during at least a certain period of pre-loading the microneedle device 100, said barrier structure 400 can receive a part 513 of a lower portion 512 of the film 511 of liquid product and can support said lower portion 512 of the film 511 to such extent that it can be substantially counteracted to at least a certain extent that said lower portion 512 of the film 511 moves beyond said barrier structure 400.

[0061] As can be seen in the exemplary embodiment of Figures 1A - 1 C, in preferred embodiments, the barrier structure 400 can comprise a flange 440 extending around the lower end 310 of the microneedle 300. More preferably, an upper surface 441 of said flange 440 can then define a support surface 410 for supporting thereon a lower end of the film 511 of liquid product. Yet more preferably, the flange further 440 may also define a substantially upwardly extending side surface 442 connecting with the upper surface 441.

[0062] Although the barrier structure 400 is here formed as a flange 440, the barrier structure 400 may be formed differently.

[0063] For example, the barrier structure 400 may be formed by a ring or a wall-like structure 450 or the like which is laterally spaced apart from the lower end 310 of the microneedle 300, an exemplary example of which is shown in Figure 2A. The barrier structure 400 may then thus comprise a depression 460, such as a groove 460 or a gutter or the like. It is noted that the wall-like structure 450 or the like does not need to be free of openings, and may for example also be formed as row of upwardly extending protrusions which together surround the lower end 310 of the microneedle 300.

[0064] It is for instance also feasible to refrain from such a ring or wall-like structure 450 or the like, but provide the depression 460 directly into the top surface 210 of the base support 200, an exemplary embodiment of which is shown in Figure 2B. Also in such embodiments, the barrier structure 400 may then thus comprise a depression 460, such as a groove 460 or a gutter or the like.

[0065] Not only in such embodiments comprising a depression 460, such as embodiments shown in Figures 2A an 2B for instance, but for example also in embodiments in which the barrier structure 400 comprises or is formed as a flange 440 directly connected to the lower end 310 of the microneedle 300 such as for instance is the case in the exemplary embodiment of Figure 1 C, the support surface 410 of the barrier structure 400 has a width W410. Said width W410 may be measured in a direction parallel to the top surface 210 of the support base 200 and measured in direction extending substantially radially away from the microneedle 300 at its lower end 310.

[0066] Said width W410 of the support surface 410 may, at is smallest point W410’, be at least 3% of the width W310 of the lower end 310 of the microneedle 300 at it widest point W310”, preferably at least 5% or at least 8%, more preferably at least 10%, yet more preferably at least 15% or at least 20%, such as for instance at least 25% or at least 30%. By facilitating that the width W410, or at least the width at its smallest point W410’, has a such certain minimal dimension, it can be facilitated that there is enough space to support the respective part 513 of the lower portion 512 of the film 511 of liquid product located on the outer surface 320 of the microneedle 300.

[0067] On the other hand, by limiting the width W410, or at least limiting the width at its widest point W410”, of the support surface 410, it can be counteracted that relatively much of the liquid product 500, and thus of the drug or other substance to be loaded onto the microneedle 300 by means of said liquid product 500, may be disposed on the support surface 410 where it may be wasted to at least a certain extent. For instance therefore, the smallest width W410’ of the support surface 410 of the barrier structure 400 may be chosen such that it does not substantially exceed the width W310, in particular the widest width W310”, of the lower end 310 of the microneedle 300. In particular, said smallest width W410’ of the support surface 410 may be chosen to be at most 65% of the largest width W310” of the lower end 310 of the microneedle 300, more preferably at most 50%, yet more preferably at most 35%, such as for instance at most 25% or 20%.

[0068] It is noted that the support surface 410, as is the case in the embodiments shown in the figures, may be a substantially laterally extending support surface. Although said laterally extending support surface 410 extends horizontally and parallel with the top surface 210 of the base support in the here shown embodiments, it may in alternative embodiments be designed differently, and may for example be curved to a certain extent.

[0069] As mentioned above, the barrier structure 400 can advantageously be formed as a flange 440, and the width of said flange, or at least the width of the support surface W410 defined by the top surface 441 of said flange 400, does not need to have the same size around the entire periphery of the lower end 310 of the microneedle. This can for instance be appreciated when comparing the embodiment of Figures 3A - 3C with the alternative embodiment shown in Figures 6A - 6C. As can be seen, in Figures 6A - 6C, the flange 440 has substantially the same constant width along the entire periphery of the lower end 310 of the microneedle 300, whereas the width of the flange 440 provided at the microneedle 300 of the embodiment of Figures 3A - 3C varies along the periphery of the lower end 310 of the microneedle 300. Indeed, the widest width W410” of the support surface and / or the flange may be substantially larger than the width of the support surface and / or the flange at its smallest point W410’.

[0070] In this context, it is noted that in case the width of the support surface 410 and / or the flange 440 substantially differs along the periphery of the lower end 310 of the microneedle 300, the outer edge of the flange 440 may be substantially circular and / or may have a shape substantially corresponding with the main shape of the microneedle, which main shape may be circular or round cylindrical and may be provided with a recess or cove which is not present in the flange 440. It will be appreciated that, at least in embodiments, the flange may be formed as a substantially round disk 449. However, in other embodiments, such as embodiments corresponding more or less with the embodiment shown in Figures 6A - 6C, the shape of the flange 440 may more or less follow the shape of the lower end 310 of the microneedle 300. At least in embodiments in which the barrier structure 400 comprises a flange 440, the barrier structure 400 may further thus define a substantially upwardly extending side surface 420, 442, which can extend in a substantially downward direction from the connection 430 between the substantially laterally extending support surface 410 and said substantially upwardly extending side surface 420, 442.

[0071] The side surface 420, 442 and / or the connection 430 between said side surface 420, 442 and the support surface 410 is arranged for substantially obstructing said part of said lower portion 512 of the film 511 of liquid product 500 from flowing from the support surface 410 onto the top surface 210 of the support base 200 of the microneedle device 300. Thereto, said connection 430 may be formed by a relatively sharp edge 430. For instance, said relatively sharp edge may have a rounding radius of less than 5 pm or less than 3 pm, preferably less than 1 pm, more preferably less than 0.5 pm, yet more preferably less than 0.25 pm.

[0072] It is noted that near the location of the connection 430 between the side surface 420 of the barrier structure 400 and the support surface 410 of the barrier structure 400, said side surface 420 and said support surface 410 may extend with respect to each other under an angle a in the range of 70° to 110°, said angle a preferably being in the range 80° to 100°, more preferably 80° to 95°, such as for instance about 90°.

[0073] Besides, additionally or alternatively, the the substantially upwardly extending side surface 420, 462 of the barrier structure 440 and / or the entire barrier structure 440 may have a height H420, H400, measured in a direction transverse to the top surface 210 of the support base 200, wherein said height H420 of said side surface 420 and / or said height H400 of the barrier structure 400 may be at least 3% of the largest width W310” of the lower end 310 of the microneedle 300, preferably at least 5%, more preferably at least 8%, yet more preferably at least 10%, such as for instance at least 12% or 15%.

[0074] For example, in case the barrier structure 400 is in the form of a flange 440 or the like or in the form of a wall-like structure 450 or the like, the height H400 of the barrier structure 400 may be limited to a certain extent, for instance to counteract that the support structure may irritate a patient or the like. Said height H400 of the barrier structure 400 and / or the height H420 of the side surface 420 may for instance be chosen such that it does not substantially exceed the largest width W310” of the lower end 310 of the microneedle 300. Preferably, said respective height H400, H420 may be at most 65% of the largest width W310” of the lower end 310 of the microneedle 300, more preferably at most 50%, yet more preferably at most 35%, such as for instance at most 25% or 20%.

[0075] Alternatively or additionally, the height H400 of the barrier structure 400 and / or the height H420 of the side surface 420 may for instance be at least 2% of the height H300 of the microneedle 300, preferably at least 3%, more preferably at least 4%, yet more preferably at least 5%, such as for instance at least 6%, wherein said height H300 of the microneedle 300 is measured from the top surface 210 of the support base 200 to the tip 333 of the microneedle in a direction transverse to said top surface 210.

[0076] In embodiments, alternatively or additionally, the height H400 of the barrier structure 400 and / or the height H420 of the side surface 420 may for instance be between 10 pm and 120 pm, preferably between 20 pm and 80 pm, such as for instance between 30 pm and 60 pm, for instance about 40 pm or about 50 pm. With respect to Figures 2A and 2B, it is noted that in embodiments in which the barrier structure 400 comprises a depression 460, such as a groove 460 or a gutter 460 or the like, which may extend around the lower end 310 of the microneedle 300, said depression 460 can comprise a substantially upwardly extending side 420, 462, which may be offset from the lower end 310 of the microneedle 300 such that the depression 460 may have substantially the same width along the periphery of the lower end 310 of the microneedle 300. However, the depression 460 does not necessarily have to have a substantially constant width, and may for example have an outer shape, e.g. one bordered by means of the depression 460, which for instance may correspond with the main shape or so-called base shape of the microneedle 300, and may thus be substantially round or circular, even if such main shape of the microneedle 300 may be provided with a recess or cove or the like. For example, the depression 460 may in a top view thus be substantially similarly shaped as the flanges 440 shown in Figures 3B and 6B.

[0077] In embodiments, near the location of the connection 430 between the side surface 420, 462 of the barrier structure 400 and the support surface 410 of the barrier structure 400, said side surface 420, 462 and said support surface 410 may extend with respect to each other under an angle p in the range of 70° to 110°, said angle preferably being in the range 80° to 100°, more preferably 80° to 95°, such as for instance about 90°. As can be seen in Figures 3A - 6C, which show different embodiments of a microneedle device 100 comprising a support base 200 and at least one microneedle 300, wherein the support base 200 then defines a top surface 210 and the at least one microneedle 300 projects upwards from said top surface 210, said microneedle 300 can preferably have a shape 600 which is partly defined by a substantially cylindrical shape 610, preferably a substantially round cylindrical shape. Although the substantially cylindrical shape 610 may preferably thus have substantially round base, the substantially cylindrical shape 610 may alternatively have a differently shaped base, such as for example substantially elliptical-shaped base.

[0078] Although said substantially cylindrical shape 610 may, as is for instance the case in the exemplary embodiment shown in Figures 3A - 3C, define at least a section of a cylindrical outer surface 620 which at least partially extends vertically with respect to the top surface 210 of the support base 200, the substantially cylindrical shape 610 may in alternative embodiments taper to some extent, in particular taper in an upward direction away from the top surface 210 of the support base 200, as can be seen for instance in Fig. 4 in which a section of a substantially cylindrical outer surface 620’ tapers to a certain extent.

[0079] It is noted that the skilled person appreciates that in the context of the present disclosure a substantially cylindrical shape 610 may thus also relate to shapes which taper to certain extent, for instance shapes tapering under an angle of at most 10°, for example at most 8°, such as an angle of at most 5°, which angle may in particular form a so-called draft angle for facilitating removing the microneedle 300 from a mould in which it may be formed. Although such shapes may theoretically be considered to be based on cones or truncated cones, they can, in the context of the present disclosure, nevertheless be considered to be substantially cylindrical shapes.

[0080] The substantially cylindrical shape 610 can then further be provided with two bevels 331 , 332, which are formed by two oblique surfaces 331 , 332, at the upper end of the microneedle. Said two bevels 331 , 332 connect to each other at a cutting edge 334 which is oblique with respect to a central axis A600 of the substantially cylindrical shape 600. The cutting edge 334 ends in a tip 333 which defines a distal end of the microneedle 300. The shape 600 of the microneedle 300 is here further formed by a cavity 640 which protrudes into the microneedle 300 from its upper end in a downward direction towards a proximal end of the microneedle 300. Preferably, the cavity 640 may extend downward over at least 50%, more preferably at least 75%, yet more preferably at least 90% of the length of the microneedle 300.

[0081] It is noted that although the cross-section of the cavity 640, transverse to the length of the microneedle 300, may be substantially constant along the length of microneedle, this is not necessary. For example, at the bottom of the cavity, the cavity may be rounded, as for instance can be seen in Fig. 4. This may for instance facilitate a relatively clean release from a mould.

[0082] It is noted that in embodiments the microneedle 300 may for instance have a substantially shovel-like shape 601 , as for example can be seen in Figures 3A - 3B, 4 and 6A - 6C. In such embodiments, the cavity 640 extends through a lateral side of the substantially cylindrical shape 610 which partly defines the shape 600 of the microneedle 300. As can be seen in Figures 3B and 6B, the cavity 640, when seen from above, can then extend through a lateral side 622 of the substantially cylindrical shape 610 located substantially opposite to the lateral side 621 at which the tip 333 is located. In particular, the resulting shape 600 of the microneedle 300 may, when seen from above, thus be substantially C-shaped over at least a certain length of the height of the microneedle, as can be seen from Fig. 3B and Fig. 6B.

[0083] As further can be seen in Fig. 3B and Fig. 6B, when seen from above or in a cross-section transverse to the length direction of the microneedle, the cavity 640 can have a substantially elliptical, oval or cylindrical shape.

[0084] Preferably, when seen from above, an axis A650, in particular a major axis, of said substantially elliptical, oval or cylindrical shape, may lie substantially parallel to the cutting edge 334. More preferably, said axis A650 can, when seen from above, substantially coincide with said cutting edge 334.

[0085] In embodiments, the major axis of the substantially elliptical, oval or cylindrical shape may be substantially equal or larger than a width W310, in particular a smallest width, which may be the diameter W310, of the substantially cylindrical shape 610.

[0086] In embodiments, said major axis may for example be in the range about 75% to 150%, preferably in the range of 85% to 125% of the smallest width W310 of the substantially cylindrical shape 610.

[0087] Additionally or alternatively, the major axis of the substantially elliptical, oval or cylindrical shape may for example be 1.5 to 6 times larger than its minor axis. In embodiments, the smallest width W310, e.g. the diameter W310, of the substantially cylindrical base shape 610 of the microneedle 300 may for example be in the range of 150 pm to 350 pm, preferably in the range of 200 pm to 300 pm, such as for example about 250 pm or about 260 pm.

[0088] Advantageously, the major axis may have a length in the range of 150 pm to 350 pm, preferably in the range of 200 pm to 300 pm, such as for example about 240 pm or about 250 pm.

[0089] Additionally or alternatively, the minor axis may have a length in the range of 30 pm to 200 pm, preferably in the range of 50 pm to 150 pm, such as for example about 120 pm, about 90 pm or about 60 pm.

[0090] Although the microneedle 300 may advantageously thus have a substantially shovel-shaped design, it may be formed differently.

[0091] In an advantageous embodiment, the cavity 640 may, when seen from above, be enclosed by an outer wall of the microneedle 300, as for example can be seen in Figure 5B. The cavity 640 may then, when seen from above, extend over both bevels 331 , 332, thereby splitting up the cutting edge 334 in two separate cutting edge sections 334’, 334”. As can be seen relatively well in Fig. 5A, a lower one 334” of said two separate cutting edge sections 334’, 344” then defines a second tip 333’, which for example may facilitate that the microneedle 300 can provide for a relatively good piercing ability. Besides, the connections 335, which may form relatively sharp connection edges 335 between the cavity 640 and the bevels 331 , 332 forming additional cutting edges 335, which may facilitate that a relatively low force may be required to have the microneedle 300 pierce for instance skin or other tissue.

[0092] In such embodiments, the cavity 640, when seen from above, may for example have a substantially shield-shaped shape 670 over at least a certain extent of the length of the microneedle, such as for example is the case in the exemplary embodiment shown in Fig. 5B. Such a substantially shield-like shape 670 may at least partly be defined by a section 671 of a first substantially elliptical, oval or cylindrical shape having its axis A671 , in particular its major axis, substantially coinciding with the cutting edge 334. Said substantially shield-shaped shape 670 can then further be partly defined by a section 672 of a second substantially elliptical, oval or cylindrical shape. Said second substantially elliptical, oval or cylindrical shape may preferably have a second axis A672 substantially coinciding with the cutting edge 334. Preferably, the section 672 of the second substantially elliptical, oval or cylindrical shape is a section of a substantially cylindrical shape and is, when seen from above, extending substantially parallel with a lateral outer side 370 of the microneedle 300.

[0093] Additionally, or alternatively, the section 671 of the first substantially elliptical, oval or cylindrical shape can be a section of a substantially elliptical shape and, when seen from above, said section 671 of said substantially elliptical shape can then extend, in a direction parallel to the cutting edge 334, over a distance D671 being longer than the distance D672 over which the section 672 of the second substantially elliptical, oval or cylindrical shape extends.

[0094] It is noted that although microneedle devices 100 having one or multiple microneedles 300 having an advantageous shape 600 at least partly defined by the cavity 640 may in advantageous embodiments additionally also comprise a barrier structure 400, such advantageous microneedle designs may also be advantageously used in embodiments in which they lack such barrier structures 400.

[0095] It is noted that the microneedle device 100 may be pre-loaded, for instance with a substance provided at least partly at an outside surface of its at least one microneedle 300. Additionally, or alternatively, the substance may be absorbed at least partly in the at least one microneedle 300. For instance therefore, the microneedle 300 may comprise a substantially porous structure, for example one comprising open and interconnected pores or so-called micropores. For example thereto, at least the one or multiple microneedles 300 may be made of a ceramic material or a polymer-ceramic composite. However, in other embodiments, other suitable materials may be used, for instance a polymer or a metal or the like.

[0096] It will be appreciated that pre-loaded microneedle device 100 may be packed, for example in a hermetically and / or airtight sealed package.

[0097] In order to pre-load the microneedle device 100, a liquid product may be applied to the at least one microneedle 300, for instance by means of dipping the at least one microneedle 300 into the liquid product or for instance by means of inkjet loading or spaying or the like. At least a part of the applied liquid product can then form a substantially liquid film at an outer surface of the microneedle.

[0098] Subsequently, the applied liquid product can be allowed to harden, for example dry up, to at least a certain extent. The barrier element 400, which is part of the microneedle device 100 itself and which extends substantially around a lower end 310 of the microneedle 300, may then counteract to at least a certain extent that at least a part 513 of a lower portion 512 of said initially substantially liquid film 511 can slide or flow away substantially beyond said barrier structure 400. Preferably, the barrier structure 400 may do so at least partly by supporting said lower portion 512 of the film 511 at least partly on top of a substantially laterally extending support surface 410 of said barrier structure 400.

[0099] It is noted that in order to load the one or multiple microneedles 300 with a desired amount of substance, the above-mentioned steps can be repeated, for example two, three, four, five or even more than five times, for instance even dozens of times. For example, in case the microneedle 300 is to be coated with the substance, multiple layers of said substance may thus be applied over each other.

[0100] It is noted that for the purpose of clarity and a concise description, features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.

[0101] Further it is noted that the invention is not restricted to the embodiments explicitly described herein. It will be understood that many variants are possible.

[0102] For example, when loading or pre-loading the one or multiple microneedles, it is not necessarily necessary to apply a liquid product to the at least one microneedle, for instance by means of dipping the at least one microneedle into the liquid product or for instance by means of inkjet loading. Indeed, a substance can be loaded by any other suitable means, for example by means of powder coating, which may be applied electrostatically and may subsequently be cured, for instance under heat or with ultraviolet light. This may be highly advantageous for microneedle devices having at least one, and preferably multiple microneedles having the advantageous shovel-like microneedle shape, or another shape at least partly defined by a cavity as mentioned above.

[0103] As another example, the microneedle devices having at least one, and preferably multiple microneedles having the advantageous shovel-like microneedle shape, or another shape at least partly defined by a cavity as mentioned above, will be considered to be disclosed both with and without a barrier structure as disclosed herein, even if they are only explicitly described in one of such embodiments. Furthermore, any combination of any disclosed microneedle shape or design with any disclosed barrier structure, as well as without any barrier structure, will be considered to be disclosed, at least implicitly, by the present disclosure.

[0104] Furthermore, it is noted that although the cavity may extend over substantially the entire length of the microneedle, this is not necessarily necessary. For example, in alternative embodiments, the cavity may be rounded off at its bottom end.

[0105] Further, it is noted that although the microneedle device 100 can be a pre- loaded microneedle device, it is also possible to that the microneedle device 100 is not pre-loaded, but is for example only loaded relatively shortly before it is to be used. For example, the at least one, and preferably multiple, microneedles 300 can be loaded with a liquid product, for example by dipping it into a bath or film of liquid product. This may for example be advantageous in case a liquid product and / or an active substance and / or a solution including the substance can only be stable for a relatively short period of time, such as for example may be the case with certain vaccines, such as for example certain mRNA-Lipid Nanoparticle vaccines or the like. Besides, additionally or alternatively, not preloading, but applying the substance only relatively shortly before use of the microneedle device 100 may be advantageous for other reasons. For example, in clinical trials, such as vaccine trials or the like, it may be not so economical to pre-load microneedle devices, in particular as only a relatively small amount of them are to be used. For example therefore, the microneedle device 100 may be loaded only relatively shortly before use, for example less than one hour, preferably less than 30 minutes, for example less than 15 minutes before use. For example in such cases, the cavity, in which liquid product can be held to a certain extent, for instance at least partly due to capillary action or the like, may facilitate that the microneedle 300 can be provided with a relatively large quantity of liquid product.

[0106] Such and other variants will be apparent for the person skilled in the art and are considered to lie within the scope of the invention as formulated in the following claims.

Claims

CLAIMS1. Microneedle device (100), comprising: a support base (200); and at least one microneedle (300), wherein the support base (200) defines a top surface (210), and wherein the at least one microneedle (300) projects upwards from said top surface (210) of the support base (200), wherein the microneedle device (100) further comprises a barrier structure (400) extending substantially around a lower end (310) of the microneedle (300), and wherein said barrier structure (400) is arranged for substantially counteracting to at least a certain extent that during at least a certain period of pre-loading the microneedle device (100) with a certain substance, at least a substantial portion of a film (511) of a liquid product (500) comprising said substance can flow out over the top surface (210) of the support base (200) when said film (511) of liquid product slides down along an outer surface (320) of the microneedle (300) to a certain extent.

2. Microneedle device (100) according to claim 1 , wherein the barrier structure (400) is arranged such that, during at least a certain period of pre-loading the microneedle device (100), it can receive a part (513) of a lower portion (512) of the film (511) of liquid product (500) and can support said lower portion (512) of the film (511) to such extent that it can be substantially counteracted to at least a certain extent that said lower portion (512) of the film (511) moves beyond said barrier structure.

3. Microneedle device (100) according to claim 1 or claim 2, wherein the barrier structure (400) comprises a substantially laterally extending support surface (410) for, during at least a certain period of pre-loading the microneedle device (100), receiving a part (513) of a lower portion (512) of the film (511) of liquid product (500), wherein the support surface (410) of the barrier structure (400) connects to a substantially upwardly extending side face of the microneedle (300) at the lower end of said microneedle,wherein the barrier structure (400) further defines a substantially upwardly extending side surface (420), wherein said side surface (420) connects to the support surface (410), and wherein said side surface (420) and / or the connection between said side surface (420) and the support surface (410) is arranged for substantially obstructing said part (513) of said lower portion (512) of the film (511) of liquid product (500) from flowing from the support surface (410) onto the top surface (210) of the support base (200) of the microneedle device (300).

4. Microneedle device (100) according to claim 3, wherein the substantially upwardly extending side surface (420) extends in a substantially downward direction from the connection between the substantially laterally extending support surface (410) and said substantially upwardly extending side surface (420).

5. Microneedle device (100) according to anyone of the preceding claims, wherein the barrier structure (400) comprises a flange (440) extending around the lower end (310) of the microneedle (300), preferably wherein an upper surface (441) of said flange (440) defines a support surface (410) for supporting thereon a lower end of the film (511) of liquid product, more preferably wherein the flange (440) further defines a substantially upwardly extending side surface (420) connecting with the upper surface (441).

6. Microneedle device (100) according to anyone of claims 3 - 5, wherein the support surface (410) of the barrier structure (400) has a width (W410), measured in a direction parallel to the top surface (210) of the support base (200) and measured in direction extending substantially radially away from the microneedle (300) at its lower end (310), wherein said width (W410) of the support surface, at its smallest point, is at least 3% or at least 5% of the width (W310) of the lower end (310) of the microneedle (300), preferably at least 10%, more preferably at least 15%, yet more preferably at least 20%, such as for instance at least 25% or at least 30%.

7. Microneedle device (100) according to anyone of claims 3 - 6, wherein the support surface (410) of the barrier structure (400) has a width (W410), measured in a direction parallel to the top surface (210) of the support base (200) and measured in direction extending substantially radially away from the microneedle (300) at its lower end (310), wherein said width (W410) of the support surface (410), at the smallest point (W410’) of said width, does not substantially exceed the largest width (W310”) of the lower end (310) of the microneedle (300), preferably said smallest width (W410’) of the support surface (410) being at most 65% of the largest width (W310”) of the lower end (310) of the microneedle, more preferably at most 50%, yet more preferably at most 35%, such as for instance at most 25% or 20%.

8. Microneedle device (100) according to anyone of claims 3 - 7, wherein the substantially upwardly extending side surface (420) of the barrier structure (400) has a height (H420), measured in a direction transverse to the top surface (210) of the support base (200), wherein said height (H420) of said side surface (420) is at least 3% of the largest width (W310”) of the lower end (310) of the microneedle (300), preferably at least 5%, more preferably at least 8%, yet more preferably at least 10%, such as for instance at least 12% or 15%; and / or wherein said height (H420) of said side surface (420) is at least 2% of the height (H300) of the microneedle (300), preferably at least 3%, more preferably at least 4%, yet more preferably at least 5%, such as for instance at least 6%.

9. Microneedle device (100) according to anyone of claims 3 - 8, wherein the substantially upwardly extending side surface (420) of the barrier structure (400) has a height (H420), measured in a direction transverse to the top surface (210) of the support base (200), wherein said height (H420) of said side surface (420) does not substantially exceed the largest width (W310”) of the lower end (310) of the microneedle, preferably said height (H420) of the side surface (420) being at most 65% of the largest width (W310”) of the lower end of the microneedle, more preferably at most 50%, yet more preferably at most 35%, such as for instance at most 25% or 20%.

10. Microneedle device (100) according to anyone of claims 4 - 9, wherein near the location of the connection (430) between the side surface (420) of the barrier structure (400) and the support surface (410) of the barrier structure, said side surface (420) and said support surface (410) extend with respect to each other under an angle (a) in the range of 70° to 110°, said angle preferably being in the range 80° to 100°, more preferably 80° to 95°, such as for instance about 90°.

11. Microneedle device (100) according to claim 3, wherein the substantially upwardly extending side surface (420) extends in a substantially upward direction from the connection (430) between the substantially laterally extending support surface (410) and said substantially upwardly extending side surface (420).

12. Microneedle device (100) according to anyone of claims 1 , 2, 3 and 11 , wherein the barrier structure (400) comprises a depression, such as a groove or a gutter or the like, extending around the lower end of the microneedle, wherein near the location of the connection between the side surface of the barrier structure and the support surface of the barrier structure, said side surface and said support surface extend with respect to each other under an angle in the range of 70° to 110°, said angle preferably being in the range 80° to 100°, more preferably 80° to 95°, such as for instance about 90°.

13. Microneedle device (100) according to anyone of the preceding claims, wherein the microneedle device comprises at least one multiplicity of microneedles, wherein each of the microneedles (300) of said multiplicity is provided with a respective barrier structure (400).

14. Microneedle device (100) according to anyone of the preceding claims, wherein the at least one microneedle (300) is loaded with a substance, for instance a substance at least partly coated onto the microneedle and / or at least partly absorbed within the microneedle.

15. Microneedle device (100), for instance a microneedle device according to any one of the preceding claims, wherein said microneedle device (100) comprises a support base (200) and at least one microneedle (300), wherein the support base (200) defines a top surface (210) and the at least one microneedle (300) projects upwards from said top surface (210), wherein the microneedle (300) has a shape (600) which is partly defined by a substantially cylindrical shape (610), preferably a substantially round cylindrical shape, which at its upper end is provided with two bevels (331 , 332) which connect to each other at a cutting edge (334) which is oblique with respect to a central axis (A600) of the substantially cylindrical shape (610), said cutting edge (334) ending in a tip (333) defining a distal end of the microneedle (300), and wherein the shape (600) of the microneedle (300) is further formed by a cavity (640) which protrudes into the microneedle (300) from its upper end in a downward direction towards a proximal end of the microneedle (300).

16. Microneedle device (100) according to claim 15, wherein the cavity (640) extends through a lateral side (622) of the substantially cylindrical shape (610) which partly defines the shape (600) of the microneedle (300), in particular wherein, when seen from above, the cavity (640) extends through a lateral side (622) of the substantially cylindrical shape (610) located substantially opposite to the lateral side (621) at which the tip (333) is located, more in particular wherein the resulting shape (600) of the microneedle (300), when seen from above, is substantially C-shaped over at least a certain extent of the length of the microneedle (300).

17. Microneedle device (100) according to claim 15 or 16, wherein, when seen from above, the cavity (640) has, over at least a certain extent of the length of the microneedle, a substantially elliptical, oval or cylindrical shape, preferably wherein, when seen from above, an axis (A650), in particular a major axis, of said substantially elliptical, oval or cylindrical shape, lies substantially parallel to the cutting edge (334),more preferably wherein said axis (A650), when seen from above, substantially coincided with said cutting edge (334).

18. Microneedle device (100) according to anyone of claims 15 - 17, wherein, when seen from above, the cavity (640) is enclosed by an outer wall of the microneedle (300), wherein the cavity (640), when seen from above, extends over both bevels (331 , 332), thereby splitting up the cutting edge (334) in two separate cutting edge sections (334’, 334”), wherein a lower one (334’) of said two separate cutting edge sections defines a second tip (333’).

19. Microneedle device (100) according to claim 18, wherein the cavity (640), when seen from above, over at least a certain extent of the length of the microneedle (300), has a substantially shield-shaped shape (670) at least partly defined by a section (671) of a first substantially elliptical, oval or cylindrical shape having its axis (A671), in particular its major axis, substantially coinciding with the cutting edge (334), wherein said substantially shield-shaped shape (670) is further partly defined by a section (672) of a second substantially elliptical, oval or cylindrical shape, said second substantially elliptical, oval or cylindrical shape preferably having a second axis (A672) substantially coinciding with the cutting edge (334), preferably wherein the section (672) of the second substantially elliptical, oval or cylindrical shape is a section of a substantially cylindrical shape and is, when seen from above, extending substantially parallel with a lateral outer side (370) of the microneedle (300).

20. Microneedle device (100) according to claim 19, wherein the section (671) of the first substantially elliptical, oval or cylindrical shape is a section of a substantially elliptical shape and, when seen from above, said section of said substantially elliptical shape extends, in a direction parallel to the cutting edge (334), over a longer distance (D671) than the section (672) of the second substantially elliptical, oval or cylindrical shape.

21. Patch comprising a microneedle device (100) according to anyone of claims 1 - 20.

22. Applicator provided with a microneedle device (100) according to anyone of claims 1 - 20.

23. Method of pre-loading a microneedle device, (100) comprising the steps of: providing a microneedle device (100), preferably a microneedle device (100) according to any one of preceding claims 1 - 20; applying a liquid product (500) to at least one microneedle (300) of the microneedle device (100), for instance by means of dipping the at least one microneedle (300) into the liquid product or for instance by means of inkjet loading, dispensing or spraying or the like, wherein at least a part of the applied liquid product (500) forms a substantially liquid film (511) at an outer surface of the microneedle (300); and allowing the applied liquid product (500) to harden, for example dry up, to at least a certain extent, while a barrier element (400), which is part of the microneedle device (100) itself and which extends substantially around a lower end of the microneedle (300), counteracts to at least a certain extent that at least a part (513) of a lower portion (512) of said initially substantially liquid film (511) can slide or flow away substantially beyond said barrier structure (400), preferably at least partly by supporting said lower portion (512) of the film (511) at least partly on top of a substantially laterally extending support surface (410) of the barrier structure (400).

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