Device for applying microneedle array to skin

Abstract

Microneedle arrays and drug delivery devices are provided for transdermally delivering a drug formulation to a patient. The microneedle array device includes a substantially planar substrate having an array of apertures; and a plurality of microneedles projecting at angle from the planar substrate, the microneedles having a base portion integrally connected to the substrate, a tip end portion distal to the base portion, and body portion therebetween, wherein each microneedle has at least one channel extending substantially from the base portion through at least a part of the body portion, the channel being open along at least part of the body portion and in fluid communication with at least one of the apertures in the substrate. In a preferred embodiment, each microneedle has a substantially rectangular cross-sectional shape and the channel is open to two opposing surfaces of the microneedle.

I claim: 
     
         1 . An applicator device for applying a microneedle array to skin, comprising:
 a housing having an application side and an opposed top side;   a recess in the housing in which a drug delivery device that includes an array of microneedles can be releasably stored;   a button on the top side of the housing, which button can be depressed to drive the drug delivery device out of the recess for insertion into a patient's skin with the microneedles oriented substantially perpendicular to the planar application side; and   at least one roller disposed partially in a cavity on the planar application side of the housing, the roller being configured to facilitate (i) complete insertion of the microneedles into the skin and/or (ii) a bond between the drug delivery device and the skin.   
     
     
         2 . The applicator device of  claim 1 , further comprising a drug delivery device that includes an array of microneedles. 
     
     
         3 . The applicator device of  claim 2 , wherein the drug delivery device further comprises a drug storage element, which contains a drug formulation, and is configured to release the drug formulation to the microneedles. 
     
     
         4 . The applicator device of  claim 2 , wherein the substrate and the microneedles are formed of stainless steel or another biocompatible metal. 
     
     
         5 . The applicator device of  claim 2 , wherein the array of microneedles comprises:
 a substantially planar substrate having an array of spaced apertures therein;   a plurality of microneedles projecting at angle from the plane in which the planar substrate lies, the microneedles having a base portion integrally connected to the substrate, a tip end portion distal to the base portion, and body portion therebetween, wherein at least one of the microneedles has at least one channel extending substantially from the base portion through at least a part of the body portion, the channel being open along at least part of the body portion and in fluid communication with at least one of the apertures in the substrate.   
     
     
         6 . The applicator device of  claim 5 , wherein at least one of the microneedles has a substantially rectangular cross-sectional shape in a plane parallel to the substrate. 
     
     
         7 . The applicator device of  claim 5 , wherein the at least one channel is open to two opposing surfaces of the microneedle. 
     
     
         8 . The applicator device of  claim 5 , wherein the tip end portion of the at least one of the microneedles is tapered. 
     
     
         9 . The applicator device of  claim 8 , wherein the at least one channel terminates in the body portion of the microneedle and does not extend into the tapered tip portion. 
     
     
         10 . The applicator device of  claim 5 , wherein the body portion of the at least one microneedle is rectangular with a centrally located channel extending through the opposed longer sides of the body portion. 
     
     
         11 . The applicator device of  claim 5 , wherein the apertures in the substrate are polygonal in shape, each aperture being defined by three or more interior side surfaces in the substrate. 
     
     
         12 . The applicator device of  claim 11 , wherein the base portion of the at least one microneedle includes a curved portion that extends from at least one of the interior side surfaces of the substrate. 
     
     
         13 . The applicator device of  claim 5 , wherein the tip end portion is tapered, the body portion is rectangular, and the channel extends through 50% to 99% of the length of the microneedle substantially form the planar substrate, through the base, and through at least a part of the body portion. 
     
     
         14 . The applicator device of  claim 5 , wherein the drug delivery device further comprises a drug storage element, which contains a drug formulation and is attached to a first surface of the planar substrate, the first surface being opposed to a second surface of the planar substrate of the microneedle array, wherein the microneedles project from the second surface. 
     
     
         15 . The applicator device of  claim 14 , further comprising a release mechanism for releasing the drug formulation from the drug storage element to permit the drug formulation to pass into and through the at least one channel of the at least one microneedle. 
     
     
         16 . The applicator device of  claim 14 , wherein the drug formulation is a fluid and wherein the at least one elongated channel is dimensioned to provide a capillary effect to wick the fluid into the base portion of the microneedle from the substrate aperture, through the body portion of the microneedle, and toward the tip portion of the microneedle. 
     
     
         17 . The applicator device of  claim 1 , wherein the at least one roller is cylindrical.