Modulation of transdermal drug delivery with coated microneedles

Coated microneedles have attracted enormous interest in scientific circles especially for the delivery of vaccines. But there are challenges to be overcome especially with regards to optimizing coating efficiency and improving transcutaneous delivery. In this review, the different techniques used for fabricating coated microneedles are discussed. In addition, different formulations of the coating dispersions are also highlighted including an interesting study on the use of a charge reversal copolymer. Specific examples of the use of these microneedle systems for the delivery of different drugs and vaccines are also given.