Evaluation of sulfobutylether-β-cyclodextrin complex loaded dissolving microneedles-mediated delivery of fluticasone...

Atopic dermatitis (AD) is a chronic inflammatory skin disease that often requires corticosteroid therapy; however, conventional topical delivery can be limited by poor drug solubility. This study aimed to fabricate and evaluate sulfobutylether-β-cyclodextrin (SBE-β-CD) inclusion complex-loaded dissolving microneedles for the microneedle delivery of fluticasone propionate (FP) in AD. The aqueous solubility of FP was enhanced through complexation with SBE-β-CD, followed by incorporation of the resulting inclusion complex into dissolving microneedles. The fabricated MNs were comprehensively characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), drug content analysis, insertion testing, in vitro release studies, and in vivo evaluation over a period of 15-day treatment in six groups of BALB/c mice, including primary comparison groups (the vehicle and commercial topical controls). SEM confirmed uniform microneedle morphology; FTIR indicated between FP and the formulation components. Drug content showed 98% recovery; each MN patch contained 56.93 µg FP per 7.84 mm². Insertion testing demonstrated 100% initial surface insertion was 100% with penetration efficiency progressively decreasing across deeper paraffin layers, reaching 50% in the fourth layer and 0% by seventh layer. In vitro drug release followed first-order kinetics (R² = 0.987) and showed sustained FP release for up to 24 h. In vivo, the shafts of the SBE-β-CD/FP MN arrays completely dissolved within 25 min after insertion into BALB/c mouse skin, indicating rapid microneedle dissolution. Treatment with SBE-β-CD/FP MNs reduced skin erythema, inflammatory cell infiltration, epidermal thickness, hyperkeratosis, and spongiosis. These findings suggest that SBE-β-CD/FP microneedles are a promising platform for FP delivery in AD.