IN VITRO, EX VIVO, AND IN VIVO EVALUATION OF A HERBAL NANOEMULSION GEL FOR THE MANAGEMENT OF PSORIASIS

Abstract

Psoriasis is a chronic inflammatory skin disorder marked by excessive keratinocyte proliferation and an overproduction of pro-inflammatory cytokines. In this work, we developed and fine-tuned a herbal nanoemulsion gel intended for topical psoriasis management, with the hope of improving drug delivery while balancing efficacy and safety. The optimized formulation—settled on after several less-than-ideal trial runs—yielded droplets averaging 96.4 ± 3.2 nm, a low polydispersity index (0.18 ± 0.01), and a zeta potential of −34.2 ± 1.5 mV. Drug encapsulation was consistently high (86–93%), and release profiles suggested a sustained delivery pattern (91–95% over 12 h), though whether this will fully translate in patient skin remains to be confirmed. Once incorporated into a gel base, the preparation retained its physicochemical stability and exhibited pseudoplastic flow. Spreadability measured 6.3 ± 0.4 cm and the pH hovered at 6.1 ± 0.2—comfortably within the skin-friendly range. Cytotoxicity testing on HaCaT cells indicated >85% viability at 100 µg/mL, and ELISA assays showed substantial reductions in TNF-α (70.37%), IL-6 (70.79%), and IL-17 (73.10%). Ex vivo skin permeation data pointed to a controlled release profile (82.2 ± 3.1 µg/cm² cumulative permeation, flux 11.3 ± 0.5 µg/cm²/h). In a murine imiquimod-induced psoriasis model, PASI scores dropped from 3.2 to 2.0 by day 7, accompanied by histological improvements. No visible irritation, erythema, or edema was noted. While the results collectively suggest a stable, safe, and biologically active preparation, longer-term and broader-scale studies will be needed to verify its clinical relevance.