Dissolvable-tipped, drug-reservoir integrated microneedle array for transdermal drug delivery

This paper presents a dissolvable-tipped, drug-reservoir integrated microneedle array for transdermal drug delivery. The hydrogel-based dissolvable tips are formed in a reusable polydimethylsiloxane (PDMS) mold, and then contact-transferred onto a microtube array with drug-surrogate pre-filled reservoirs incorporated into each microneedle. The microtube array is fabricated by a single photolithography process using a gray-tone mask. After insertion into an agarose gel, the water-soluble tips effectively dissolve within a minute to expose each reservoir, and the pre-filled drug-surrogate successfully diffuses. A preliminary tissue penetration test shows mechanical stability of the dissolvable tipped microneedle and feasibility of drug delivery as well as safe prevention of the proposed microneedle from possible reuse.