Microneedle Arrays

Abstract

Microneedle arrays made by an injection molding process that uses ultrasonic energy to assist flow of polymer melt into a mold cavity, said microneedles having a high proportion (at least 60%) of fill, i.e., completely formed microneedles across the array. Microneedle array can be on a base or land no more than 250 μm thick.

What is claimed is: 
     
         1 . A microneedle array made of polymeric material comprising a multiplicity of microneedles having a height of 20 to 1000 micrometers and an aspect ratio greater than 2:1 on a land, characterized by at least 60 percent of the microneedles across the array being filled, the term filled meaning that the microneedle mold cavities used to form the microneedles were filled with polymeric material to form complete microneedles. 
     
     
         2 . The microneedle array of  claim 1  comprising 10 to 1288 microneedles. 
     
     
         3 . The microneedle array of  claim 1  comprised of a polymer selected from the group consisting of polyphenyl sulfides, polycarbonates, polypropylenes, acetals, acrylics, polyetherimides, polybutylene terephthalates, polyethylene terephthalates, and blends thereof. 
     
     
         4 . The microneedle array of  claim 1  having a land no more than 250 micrometers thick