Method and Device for Manufacturing Microneedle Elements and a Microneedle Element

Abstract

A method for manufacturing a microneedle element, including the following steps: providing a mold element for the microneedle elements to be manufactured, filling the mold element with a first formulation, curing the first formulation, and pressurizing the first formulation during curing. Furthermore, a microneedle element and a device for manufacturing a microneedle element.

Claims

1. A method for manufacturing a microneedle element comprising at least one microneedle, the method comprising the following steps: providing a mold element for the microneedle elements to be manufactured; filling the mold element with a first formulation, in particular a backing formulation, curing the first formulation, and pressurizing the first formulation during curing.

2. The method according to claim 1, wherein the method comprises, before the step of filling the mold element with the first formulation, the following further step: filling the mold element with a second formulation, in particular a tip formulation.

3. The method according to claim 2, wherein the method comprises, after the step of filling the mold element with the second formulation, the following further step: curing the second formulation, in particular with simultaneous pressurization.

4. The method according to claim 3, wherein the method comprises, before the step of filling the mold element with the first formulation and after the step of filling the mold element with the second formulation, the following further step: filling the mold element with at least one additional formulation, in particular an intermediate formulation, and preferably curing the at least one additional formulation, in particular with simultaneous pressurization.

5. The method according to claim 1, wherein, when filling the mold element with the first formulation, the mold element is overfilled so that the first formulation emerges from the mold element.

6. The method according to claim 1, wherein drying, in particular air drying, takes place during curing.

7. The method according to claim 1, wherein temperature is applied during curing.

8. The method according to claim 1, wherein the pressurization is realized by means of overpressure and/or by means of a pressing device, in particular comprising a punch and/or a roller.

9. The method according to claim 1, wherein the pressurization and/or curing is carried out over a period of at least 30 minutes, preferably at least 60 minutes, particularly preferably at least 90 minutes.

10. The method according to claim 1, wherein the mold element comprises several microneedle negative molds, wherein the several microneedle negative molds in particular form a microarray negative mold.

11. The method according to claim 1, wherein the mold element is filled with the first formulation such that the first formulation covers the several microneedle negative molds.

12. A microneedle element, in particular a microneedle or microarray, obtainable by a method according to claim 1.

13. A device for manufacturing a microneedle element comprising at least one microneedle, in particular according to a method according to claim 1, the device comprising: a mold element for the microneedle elements to be manufactured, a pressurization device, in particular comprising an overpressure chamber, and preferably a drying device, in particular generating heat and/or air flow, wherein the pressurization device is configured such that a pressure is applied to the mold element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The terms FIG., FIGS., Figure, and Figures are used interchangeably in the specification to refer to the corresponding figures in the drawings.

[0026] In the following, the invention is described in more detail by means of a preferred embodiment with reference to the accompanying drawings.

In the Figures:

[0027] FIGS. 1a-1f are schematically sectioned side views of a die in different conditions for illustrating a method for manufacturing microneedle elements according to prior art,

[0028] FIG. 2 is a detailed view according to II of FIG. 1f for illustrating a microneedle element in the form of a microneedle of prior art,

[0029] FIG. 3 is a schematically sectioned side view of a die in a condition for illustrating an embodiment of a method for manufacturing a microneedle element according to the invention,

[0030] FIG. 4 is a detailed view according to IV of FIG. 3 for illustrating an embodiment of a microneedle element according to the invention in the form of a microneedle,

[0031] FIGS. 5-6 are schematically sectioned side views of a die in a condition for illustrating a further embodiment of a method for manufacturing microneedle elements according to the invention with further embodiments of microneedle elements according to the invention, and

[0032] FIGS. 7-9 are schematically sectioned side views of embodiments of devices for manufacturing a microneedle element according to the invention, comprising a die in a condition for illustrating further embodiments of a method for manufacturing microneedle elements according to the invention.

DESCRIPTION OF THE INVENTION

[0033] In the Figures, similar or identical components or elements are identified by the same reference numerals or variations thereof (e.g. 22 and 22). In particular for improved clarity, preferably already identified elements are not provided with reference numerals in all Figures.

[0034] FIGS. 1a-1f and 2 are already described above.

[0035] FIG. 3 is based on FIGS. 1a-1f. Here, a state following the state shown in FIG. 1f is shown, but (in FIG. 1f) the backing formulation 20 has not yet hardened and/or dried.

[0036] Pressure is applied to the not yet hardened, in particular moist, backing formulation 20 (FIG. 3). This pressurization can be realized by means of physical pressure, e.g. by means of a stamp (cf. FIG. 8) or by means of a roller. A pressurization by means of overpressure, e.g. by means of an overpressure chamber (cf. FIG. 7), is preferred. Said overpressure is in particular approx. 3 bar compared to ambient pressure. The pressurization occurs simultaneously with the curing of the backing formulation 20. Preferably, the pressurization takes place for at least 30 minutes. Thus, a pressure is applied to the backing formulation 20 over a period of time.

[0037] The applied pressure causes compression of the air pocket, which in FIG. 3 is an air bubble. The air bubble forms a cavity 24 between backing formulation 20 and tip formulation 14. When baking formulation 20 hardens, in particular dries, the air bubble can no longer expand. A detailed view of this is shown in FIG. 4.

[0038] Due to the compression, the air bubble and thus cavity 24 is much smaller than cavities 24 of previous manufacturing methods (cf. e.g. FIG. 2). This results in a greater bonding contact between backing formulation 20 and tip formulation 14 than in previous manufacturing methods (cf. e.g. FIG. 2). The cross-sectional area of cavity 24 is preferably smaller than the bonding surface between backing formulation 20 and tip formulation 14, in particular by at least 30%. The diameter of the cavity is in particular smaller than the diameter of microneedle 22 at the junction between backing formulation 20 and tip formulation 14, in particular by at least 30%. This minimized cavity 24 or the enlarged bonding contact between backing formulation 20 and tip formulation 14 advantageously leads to an increased stability of microneedle 22 compared to previous microneedles 22 (cf. e.g. FIG. 2).

[0039] The air pressure inside cavity 24 in particular corresponds to the applied overpressure. Preferably, the air pressure in cavity 24 is higher than the ambient pressure. The air pressure in cavity 24 is in particular higher than the air pressure in cavity 24 of prior art (cf. e.g. FIG. 2).

[0040] The microneedles 22 of FIGS. 3 and 4 correspond to an embodiment of microneedle elements according to the invention, wherein several, in particular all microneedles 22 of FIG. 3 preferably correspond to a microarray according to the invention.

[0041] FIG. 5 is also substantially based on FIG. 3. In contrast to the embodiment of FIG. 3, microarray 23 in FIG. 5 comprises microneedles 22 with three formulations 14, 20, 26. Here, the cavities 24, 28 are each miniaturized (compared to prior art).

[0042] Said small cavities 24, 28 can be implemented, for example, by separately pressurizing twice with simultaneous curing, or by pressurizing the formulations 20, 26 together and curing them simultaneously.

[0043] FIG. 6 is also substantially based on FIG. 3. In contrast to the embodiment of FIG. 3, microarray 23 of FIG. 6 is an integral microarray 23. In particular, this can be implemented by overfilling the mold openings 12 with backing formulation 20 so that backing formulation 20 binds together for several microneedles 22 to be manufactured. This bonding surface serves as a backing layer 21 for microarray 23, for example. A pressurization as defined above may be applied to the common backing formulation 20 of the several microneedles 22 to be manufactured.

[0044] FIG. 7 is also substantially based on FIG. 3. In addition to the filled mold element 10, a device 100 for manufacturing a microneedle element 23 is shown in FIG. 6.

[0045] Device 100 comprises a pressurization device 30. As illustrated, pressurization device 30 comprises a chamber 34, in particular an overpressure chamber, having a chamber wall 35. Chamber 34 encloses mold element 10 at least partially, in particular completely. An overpressure can be applied to backing formulation 20 via a pressure generator 36, in particular a pump, connected to chamber 34. As illustrated, the pressure is applied via line 46, for example.

[0046] Optionally, the device (as illustrated) can comprise a drying device 38. The illustrated drying device 38 comprises an air flow generator 40. Air flow generator 40 can in particular comprise a pump and/or a heating element. As illustrated, the drying device is connected to chamber 34 via supply line 42 and discharge line 44. Drying device 38 can be used, for example, to generate an air flow, in particular a warm air flow, for drying baking formulation 20.

[0047] Device 100 of FIG. 8 substantially corresponds to device 100 of FIG. 7, wherein another embodiment of drying device 38 is illustrated. The illustrated drying device 38 is a heating element. Here, the backing formulation is heated. This can be done, for example, by a heating device 48 generating infrared rays 50, which is arranged in chamber 34, for example.

[0048] FIG. 7 is also substantially based on FIG. 3. A further embodiment of device 100 for manufacturing a microneedle element 23 is illustrated.

[0049] Here, pressurization device 30 is a pressing device. The pressing device comprises a stamp 32 applying a physical pressure on the backing formulation.