Microprojection arrays with microprojections having large surface area profiles

Abstract

A microprojection array comprising a substrate with a plurality of microprojections protruding from the substrate wherein the microprojections have a tapering hexagonal shape and comprise a tip and a base wherein the base has two substantially parallel sides with a slight draught angle of approximately 1 to 20 degrees up to a transition point at which point the angle increases to from about 20 degrees to about 70 degrees.

1 - 26 . (canceled) 
     
     
         27 . A microprojection array comprising a substrate with a plurality of microprojections protruding from the substrate wherein the microprojections have a tapering octagonal shape and comprise a tip and a base wherein the base has two substantially parallel sides with a slight draught angle of approximately 1 to 20 degrees up to a transition point at which point the angle increases to from about 20 degrees to about 70 degrees. 
     
     
         28 . The microprojection array of  claim 27 , wherein the substrate is at least one of:
 a) solid;   b) non-porous; and   c) non-hollow.   
     
     
         29 . The microprojection array of  claim 27 , wherein the microprojection array includes a number of microprojections arranged in a line. 
     
     
         30 . The microprojection array of  claim 29 , wherein the line is at least one of:
 a) a straight line;   b) a curved line; and,   c) a circular line extending circumferentially around an axis.   
     
     
         31 . The microprojection array of  claim 30 , wherein at least some of the microprojections in a line have a common base. 
     
     
         32 . The microprojection array of  claim 31 , wherein the microprojection array includes a number of spaced apart lines. 
     
     
         33 . The microprojection array of  claim 32 , wherein the spacing of the microprojections between adjacent lines is at least one of:
 a) less than 200 μm;   b) less than 150 μm; and,   c) about 100 μm.   
     
     
         34 . The microprojection array of  claim 33 , wherein the spacing between successive microprojections is at least one of:
 a) less than 200 μm;   b) less than 150 μm;   c) less than 100 μm; and,   d) about 80 μm.   
     
     
         35 . The microprojection array of  claim 27 , wherein the tip of each microprojection terminates in an elongate edge. 
     
     
         36 . The microprojection array of  claim 27 , wherein the tip has a width of from about 1 μm to about 2 μm and a length of about 20 μm to about 2 mm.