Development and Evaluation of Hydrogel-Based Sulfasalazine-Loaded Nanosponges for Enhanced Topical Psoriasis Therapy.

The low solubility and poor skin permeability of sulfasalazine (SLZ) present significant challenges for its effective topical delivery. The objective of the current investigation is to formulate a hydrogel-based SLZ-loaded cyclodextrin nanosponge for topical therapy in psoriasis. SLZ-loaded nanosponges were prepared by the melt polymerization method and evaluated for physiochemical characteristics, drug release, and cytocompatibility. The selected nanosponges (SLZ-NS4) were transformed to hydrogel and further evaluated for rheology, texture, safety, skin permeability, and in vivo for anti-psoriatic effect in mouse tail and imiquimod-induced psoriasis-like inflammation models in mice. Physiochemical data confirms nanoscale architecture, drug inclusion in nanosponges, crystalline structure, and formulation stability. The release profile of SLZ-NS4 revealed sustained release behavior (22.98 ± 2.24% in 3 h). Cytotoxicity assays indicated negligible toxicity against THP1 cells, resulting in higher viability of cells than pure SLZ ( < 0.05). The HET-CAM assay confirmed the safety, while confocal laser scanning microscopy demonstrated deeper skin permeation of SLZ. In the mouse tail model, a remarkable decline in relative epidermal thickness, potential improvement in percent orthokeratosis, and drug activity with respect to control was observed in animals treated with SLZ-NS4 hydrogel. The efficiency of the developed SLZ-NS4-loaded hydrogel in treating psoriasis was confirmed by the decline in PASI score (81.68 ± 3.61 and 84.86 ± 5.74 with 1 and 2% / of SLZ-NS-HG). Histopathological analysis and assessment of oxidative stress markers revealed the profound anti-psoriatic potential of the fabricated SLZ-NS4 hydrogel. These findings highlight the profound potential of the developed delivery system as an effective topical therapy for psoriasis.