The fabrication and property of a novel coated out-of-plane microneedle arrays

The efficiency of transdermal drug delivery (TDD) is often undermined by stratum corneum of skin. In this paper, a novel design and fabricating process was developed to coat microneedles (MNs). Testing results of facture strength of the MNs demonstrated that the Ni coated microneedle can meet the mechanical requirement for practical TDD applications. Dip-coating experiment demonstrated that it was practical to load baicalin onto the surfaces of the MNs. The amount of loaded drug was increased simply by increasing times of dip-coating operation. It was also demonstrated that upon coated by HPMC or PVP, drug can be released from the MNs in a more sustainable manner. Coating solution had great impact on drug releasing rate, indicating that the required drug concentration can be achieved by proper coating solution.