Development of 3D printed microneedles of varied needle geometries and lengths, designed to improve the dermal delivery of topically applied psoriasis treatments.

The aim of this study was to investigate the impact of using microneedle patches in addition to topical therapy for the treatment of psoriasis. Using continuous liquid interface production (CLIP) 3D printing we manufactured round microneedle array patches (MAPs) with a diameter of 14 mm. Needle geometries were varied from square pyramidal, conical, and obelisk, with varied needle lengths of 400 µm, 600 µm, 800 µm, or 1000 µm. MAPs were characterized for force to fracture, skin penetration, skin damage, as well as their ability to deliver a novel oleogel-based corticosteroid (betamethasone dipropionate (BDP) formulation into ex-vivo porcine skin. We found that the obelisk shaped MAPs are more durable compared to the conical and square pyramidal-shaped MAPs. When the obelisk shaped MAPs were used in combination with the oleogel-based BDP formulation, the amount of BDP penetrating the skin was significantly increased with greater needle lengths.