CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims the benefit of priority to Taiwan Patent Application No. 108116699, filed on May 15, 2019. The entire content of the above identified application is incorporated herein by reference.

Some references, which may include patents, patent applications and various publications, may be cited and discussed in the description of this disclosure. The citation and/or discussion of such references is provided merely to clarify the description of the present disclosure and is not an admission that any such reference is “prior art” to the disclosure described herein. All references cited and discussed in this specification are incorporated herein by reference in their entireties and to the same extent as if each reference was individually incorporated by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to a microneedle, and more particularly to a microneedle structure and a biodegradable microneedle thereof.

BACKGROUND OF THE DISCLOSURE

For a conventional microneedle structure applied to human skin, microneedles of the conventional microneedle structure are limited to certain shapes, so that the conventional microneedle does not have enough structural strength. In order to prevent the conventional microneedle from being deformed due to without having enough structural strength, the conventional microneedle is always formed with other structural limitations. For example, a tip of the conventional microneedle has an angle within a range of 15-60 degrees for preventing the conventional microneedle from being deformed when contacting human skin.

SUMMARY OF THE DISCLOSURE

In response to the above-referenced technical inadequacies, the present disclosure provides a microneedle structure and a biodegradable microneedle thereof to effectively improve on the issues associated with conventional microneedles.

In one aspect, the present disclosure provides a microneedle structure, which includes a base and a plurality of biodegradable microneedles disposed on the base and each defining a central axis. Each of the biodegradable microneedles has a total height along the central axis and a maximum internal diameter along a direction perpendicular to the central axis. The total height is within a range of 380-430 μm, and an aspect ratio defined by the total height divided by the maximum internal diameter is within a range of 1.2-2.2. Each of the biodegradable microneedles includes a first step portion connected to the base and a second step portion taperedly extending from the first step portion along a direction away from the base. In a cross section of each of the biodegradable microneedles having the central axis, a part of the second step portion arranged away from the first step portion has a corner. The corner has an angle within a range of 65-100 degrees and faces toward the first step portion.

In certain embodiments, in each of the biodegradable microneedles, the second step portion includes a contacting end arranged away from the first step portion, and the contacting end has an arced surface having a diameter within a range of 10-25 μm.

In certain embodiments, in each of the biodegradable microneedles, the first step portion is tapered along a direction away from the base, and a top surface of the first step portion is entirely overlapped with a bottom surface of the second step portion.

In certain embodiments, the base is biodegradable, and the base and the biodegradable microneedles are integrally formed as a one piece structure.

In certain embodiments, the total height of each of the biodegradable microneedles is within a range of 380-400 μm.

In certain embodiments, in each of the biodegradable microneedles, the first step portion is a pyramidal frustum, the second step portion is a pyramid, a bottom surface of the first step portion is connected to the base, and a top surface of the first step portion is entirely overlapped with a bottom surface of the second step portion.

In certain embodiments, a ratio defined by a height of the first step portion in the total height divided by a height of the second step portion in the total height is within a range of 6.2-7.0.

In certain embodiments, in each of the biodegradable microneedles, the first step portion is a conical frustum, the second step portion is a cone, a bottom surface of the first step portion is connected to the base, and a top surface of the first step portion is entirely overlapped with a bottom surface of the second step portion.

In certain embodiments, a ratio defined by a height of the first step portion in the total height divided by a height of the second step portion in the total height is within a range of 1.8-2.6.

In one aspect, the present disclosure provides a biodegradable microneedle of a microneedle structure defining a central axis. The biodegradable microneedle includes a first step portion and a second step portion that is taperedly extending from the first step portion along the central axis. The biodegradable microneedle has a total height along the central axis and a maximum internal diameter along a direction perpendicular to the central axis, wherein the total height is within a range of 380-430 μm, and an aspect ratio defined by the total height divided by the maximum internal diameter is within a range of 1.2-2.2. In a cross section of the biodegradable microneedle having the central axis, a part of the second step portion arranged away from the first step portion has a corner. The corner has an angle within a range of 65-100 degrees and faces toward the first step portion.

Therefore, the biodegradable microneedle of the microneedle structure in the present disclosure is a two-step structure different from structure of conventional microneedle, thereby effectively reinforcing the structural strength of the biodegradable microneedle. Specifically, the biodegradable microneedle can have a stronger structural strength based on the design of the two-step structure (e.g., the aspect ratio), so that the angle of the corner of the second step portion is not limited to the conventional limitations for being manufactured easily and being applied broader.

These and other aspects of the present disclosure will become apparent from the following description of the embodiment taken in conjunction with the following drawings and their captions, although variations and modifications therein may be affected without departing from the spirit and scope of the novel concepts of the disclosure.

