Novel ethosomal gel formulation for enhanced transdermal delivery of curcumin and cyclosporine: a preclinical approach to rheumatoid arthritis management.

Abstract

Vesicular systems have demonstrated efficacy in the management of Rheumatoid Arthritis (RA). This study explores the synergistic effect of edge-activated ethosomal gel to enhance the transdermal delivery of Curcumin (CUR) and Cyclosporine (CYC). Ethosomal vesicles prepared via the ethanol injection method were incorporated into a gel, with the optimized formulation exhibiting an average particle size of 93.3 ± 1.17 nm and a zeta potential of -29.2 ± 0.17 mV. Ex vivo diffusion studies on porcine ear skin demonstrated 97.115 ± 0.40% CUR and 98.331 ± 1.08% CYC release over 18 hours, exhibiting Hixson-Crowell diffusion mechanisms. The steady-state flux and permeability coefficients were 0.095 µg/cm²/hr and 0.0095 cm/hr for CUR, and 0.0804 µg/cm²/hr and 0.01608 cm/hr for CYC respectively. In anti-inflammatory tests on lipopolysaccharide (LPS)-induced RAW 264.7 cells, the gel significantly increased IL-10 levels (p < 0.001), inhibited prostaglandin-E2, and reduced IL-6 and TNF-α levels (p < 0.001). Moreover, the ethosomal gel demonstrated nonirritating properties and exhibited significant reduction in arthritic symptoms in the Complete Freund's Adjuvant induced 28-day rat model, surpassing the effects of marketed and conventional gel. These findings highlight the synergistic benefits of combining CUR and CYC in an ethosomal gel, offering a promising alternative for RA management. Future clinical investigations are warranted to validate its safety and efficacy in humans and facilitate potential therapeutic integration.