“…Therefore, passive or/and active methods4 have been proposed to enhance the permeability of the SC. Passive methods include hydration,5,6 the use of penetration enhancers,7–9 and ways of formulating suspensions/solutions of the active ingredient 10–12. The limitation in the application of passive methods lies in that they can have a delivery time of up to several hours, hence, active methods, such as iontophoresis,13 microscission,14 and microneedles,15–21 have been and are continually being explored.…”