μ m ). ▁▁▁▁▁ ▁Research ▁has ▁shown ▁that ▁there ▁is ▁a ▁limit ▁on ▁the ▁type ▁of ▁dru gs ▁that ▁can ▁be ▁delivered ▁through ▁int act ▁skin . ▁Only ▁comp ounds ▁with ▁a ▁relatively ▁low ▁mole cular ▁weight , ▁like ▁the ▁common ▁aller gen ▁nick el ▁( 1 3 0 ▁Da ), ▁can ▁pen et rate ▁the ▁skin . ▁Comp ounds ▁that ▁we igh ▁more ▁than ▁ 5 0 0 ▁Da ▁cannot ▁pen et rate ▁the ▁skin . ▁ ▁Types ▁of ▁mic r one ed les ▁ ▁Sol id ▁ ▁This ▁type ▁of ▁array ▁is ▁designed ▁as ▁a ▁two ▁part ▁system ; ▁the ▁mic r one ed le ▁array ▁is ▁first ▁applied ▁to ▁the ▁skin ▁to ▁create ▁micro scop ic ▁well s ▁just ▁deep ▁enough ▁to ▁pen et rate ▁the ▁outer most ▁layer ▁of ▁skin , ▁and ▁then ▁the ▁drug ▁is ▁applied ▁via ▁trans der mal ▁patch . ▁Sol id ▁mic r one ed les ▁are ▁already ▁used ▁by ▁der mat olog ists ▁in ▁col lagen ▁induction ▁ther apy , ▁a ▁method ▁which ▁uses ▁repeated ▁pun ct uring ▁of ▁the ▁skin ▁with ▁mic r one ed les . ▁ ▁H ollow ▁ ▁H ollow ▁mic r one ed les ▁are ▁similar ▁to ▁solid ▁mic r one ed les ▁in ▁material . ▁They ▁contain ▁res er voir s ▁that ▁deliver ▁the ▁drug ▁directly ▁into ▁the ▁site . ▁Since ▁the ▁delivery ▁of ▁the ▁drug ▁is ▁dependent ▁on ▁the ▁flow ▁rate ▁of ▁the ▁mic r one ed le , ▁there ▁is ▁a ▁possibility ▁that ▁this ▁type ▁of