Microneedle arrays and methods of manufacturing the same

Abstract

Microneedle arrays, methods of manufacturing microneedles and methods of using microneedle arrays. The microneedles in the microneedle arrays may be in the form of tapered structures that include at least one channel formed in the outside surface of each microneedle. The microneedles may have bases that are elongated in one direction. The channels in microneedles with elongated bases may extend from one of the ends of the elongated bases towards the tips of the microneedles. The channels formed along the sides of the microneedles may optionally be terminated short of the tips of the microneedles. The microneedle arrays may also include conduit structures formed on the surface of the substrate on which the microneedle array is located. The channels in the microneedles may be in fluid communication with the conduit structures. One manner of using microneedle arrays of the present invention is in methods involving the penetration of skin to deliver medicaments or other substances and / or extract blood or tissue.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application is a divisional U.S. Ser. No. 09 / 947,195, filed Sep. 5, 2001, now allowed, the disclosure of which is herein incorporated by reference.FIELD OF INVENTION [0002] The present invention relates to the field of microneedle arrays. BACKGROUND [0003] Arrays of relatively small structures, sometimes referred to as microneedles or micro-pins, have been disclosed for use in connection with the delivery and / or removal of therapeutic agents and other substances through the skin and other surfaces. [0004] The vast majority of known microneedle arrays include structures having a capillary or passageway formed through the needle. Because the needles are themselves small, the passageways formed in the needles must be limited in size. As a result, the passageways can be difficult to manufacture because of their small size and the need for accurate location of the passageways within the needles. [0005] Another potential problem of passa...

AI Technical Summary

Benefits of technology

[0011] The present invention provides microneedle arrays, methods of manufacturing molds for microneedle arrays, and methods of manufacturing microneedles from the molds. The microneedles in the microneedle arrays are tapered structures that include at least one channel formed in the outside surface of each microneedle. The channels may assist in the delivery or removal of fluids using the microneedle arrays.

[0012] In some embodiments, the microneedles include bases that are elongated in one direction. Such a configuration may provide microneedles with improved rigidity and structural integrity as compared to microneedles that do not include elongated bases. Further, the channels in microneedles with elongated bases may extend from one of the ends of the elongated bases towards the tips of the microneedles. That configuration may also provide channeled microneedles with improved rigidity and structural integrity as compared to channeled microneedles that do not include elongated bases.

[0013] In other embodiments, the channels formed along the sides of the microneedles may optionally be terminated short of the tips of the microneedles to improve the structural integrity of the tips and potentially improve their piercing ability.

[0016] In addition to having a sufficient length, it may be preferred to provide the microneedle arrays in combination with devices that are capable of delivering the microneedle arrays to the skin in a manner that results in effective piercing of the stratum corneum. To do so, it may be preferred to apply a brief impact force to the microneedle array such that the microneedles on the array are rapidly driven into the stratum corneum.

Problems solved by technology

Because the needles are themselves small, the passageways formed in the needles must be limited in size.

As a result, the passageways can be difficult to manufacture because of their small size and the need for accurate location of the passageways within the needles.

Another potential problem of passageways small enough to fit within the microneedles is that the passageways may become easily obstructed or clogged during use.

One problem associated with penetration of skin by microneedle arrays is, however, the viscoelastic properties of skin.

Such devices are, however, relatively painful to use and may pose a risk of inadvertent piercing of skin.

Further, the pierced site may experience unnecessary bleeding.

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