Preparation and evaluation of rapid disintegrating formulation from coated microneedle

Microneedles (MNs), one of the transdermal drug delivery systems, have received extensive interest as an alternative to parenteral or parenteral administrations. For the successful drug delivery of coated MNs, the coated drug or chemical of MNs should be dissolved by skin's interstitial fluid and completely released from the MNs. Thus, the rapid disintegration of the drug from MNs plays a crucial role in ideal drug delivery of MNs. In this study, we developed the rapid disintegration coating formulation to reduce the application time of MN. The rapid disintegration MN was developed using polymers (PVA or HPMC), glycerol, croscarmellose sodium, tween 80, and Brij, as thickener, plasticizer, disintegrating agent, and surfactants, respectively. HPMC MN showed the burst release and rapid disintegration. Moreover, the drug from HPMC MN was successfully delivered into porcine skin within 1 min. In toxicological evaluation, the HPMC MN did not alter the liver and kidney function. Besides, HPMC MN did not induce the acute inflammation and change of skin structure after the application on rat skin. Thus, the coating formulation in this study could be one of the options for the development of safe and rapid disintegration MN.