PVA swelling microneedle (PVA-SMNs)-assisted enhancement of tacrolimus ointment penetration for improved psoriasis treatment.

Psoriasis is a common chronic immune-mediated inflammatory skin disease characterized by erythema and scaling, which imposes significant physical and psychological burdens on affected individuals. For facial psoriasis, clinical guidelines recommend tacrolimus (TAC) as an alternative to corticosteroid drugs due to its comparable efficacy and lower risk of adverse effects. However, in severe cases, the excessive proliferation of the stratum corneum leads to thick scales that significantly impede TAC permeation when the ointment is applied directly, resulting in unsatisfactory clinical outcomes. In this study, we propose a combination therapy involving pretreatment with swelling polyvinyl alcohol microneedles (PVA-SMNs) to create microchannels in the skin, followed by TAC ointment application. In vitro permeation tests (IVPT) revealed that PVA-SMNs enhanced the cumulative permeation of TAC by 2.7-fold. Pharmacodynamic studies further demonstrated that this approach significantly reduced the levels of key pro-inflammatory cytokines (IL-17A, IL-23, and TNF-α), which are closely associated with psoriasis pathogenesis. Clinical trials corroborated these findings, providing direct evidence of the efficacy of PVA-SMN-assisted TAC delivery in improving psoriasis treatment. These promising results highlight the potential of this novel combination strategy, which may offer better therapeutic outcomes for psoriasis patients.