Quality by design and microwave-assisted green silver nanoparticles loaded with <i>Cassia tora</i> extract for psoriasis management

The aim of this study was to develop a Cassia tora (CT)-loaded silver nanoparticle (NP) gel to enhance dermal distribution at the target site. After Box-Behnken design optimisation, the produced formulation showed an NP size of 103.77 nm, polydispersity index (PDI) of 0.2672, zeta potential (ZP) of −24.38 mV, and entrapment efficiency (EE) of 82.06 ± 2.74%. The maximum in vitro drug release was 52.67 ± 3.71% at 6 h, and confocal laser scanning microscopy (CLSM) images of rat skin showed that rhodamine B-loaded silver NP (AgNP) gel permeated far deeper than the control rhodamine B hydroalcoholic solution. In addition, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay confirmed the antioxidant activity of the enhanced CT-AgNP formulation. In the characterisation study, the gel’s extrudability and spreadability were 16.05 ± 4.24 g and 31.96 ± 4.35 g.cm.s -1 , respectively. Additionally, the CT-AgNP formulation’s exceptional stability was clearly shown by the texture analysis results. The study confirms that the AgNP formulation serves as an effective drug delivery system specifically designed for dermal administration of CT in treating psoriasis.