Microneedles with Tunable Dissolution Rate

Dissolvable microneedle (MN) patches have been widely investigated for transdermal drug delivery. The dissolution rate of MN controls the status of drug release from the MN, which in turn determines drug absorption through skin. However, no systematic approaches have been reported to tune the dissolution profile of dissolvable MN matrices. This is the first study to show polyvinylpyrrolidone (PVP)-based dissolvable MN patches with varying dissolution profiles when PVP is copolymerized with cellulose materials. The MN patches were fabricated through thermal curing and photolithography in tandem. The various grades of pharmaceutical cellulose, such as hydroxypropyl methylcellulose and methyl cellulose, have been investigated as dissolution modifier incorporated in the MN patches. The resultant MN patches had dissolution profiles ranging from 45 min to 48 h. The dissolution rates varied with the grades of cellulose materials. Besides dissolution examination, the MN patches were characterized for their mechanical strength, moisture absorption, and skin penetration efficiency. All of the MN patches were able to penetrate the human skin in vitro. Overall, the PVP MN patches have great potential for skin applications as drug carriers with tunable dissolution profiles.