Herbal microsponge gel for the treatment of cutaneous lupus erythematosus

Abstract Background Cutaneous lupus erythematosus (CLE) is a chronic, inflammatory, autoimmune skin disorder often triggered by ultraviolet light exposure. Its symptoms include skin lesions and butterfly rash on visible areas like the face, chest, and arms. Currently, there are no CLE specific FDA approved medications and the established standard treatment of CLE is associated with severe side effects. Green Tea Extract was selected as a model drug because of its known anti-inflammatory, immunomodulatory, and photoprotective properties. The present research study aimed to develop a novel herbal topical drug delivery system using microsponges as a drug carrier to enhance the therapeutic efficacy and safety of Green Tea Extract for the treatment of CLE. Results Microsponges were successfully prepared using quasi emulsion solvent diffusion method and optimized using 3 2 multilevel factorial design. Optimized microsponges were spherical porous particles as indicated by SEM with entrapment efficiency of 64.69%, particle size of 147.62 μm and production yield of 84.6%. The microsponges were dispersed in Hyaluronic acid gel base and characterized for physical parameters. Further from the in vitro and ex vivo studies, it was evident that microsponges do not penetrate transdermally. Green tea extract loaded microsponge gel gives sustained drug release of 102.29 ± 0.0014% in 14 h, and follows zero-order drug release. Using tape stripping method 457.2 μg of drug from the prepared green tea extract microsponge gel formulation was found to be retained on Stratum Corneum showing improved drug residence on the skin compared to plain gel. The in vitro cell viability assay using HaCaT cell lines suggested that the green tea extract microsponges were cell proliferative and non-toxic in nature till the maximum dose of 10 mg/ml giving more than 90% cell viability. It also showed significant anti-inflammatory activity by inhibiting the pro-inflammatory cytokines expression viz. IL-6 and TNF-alpha in LPS-induced model. The HET-CAM studies gave an IS score of 0.07 for the developed formulation suggesting it to be safe with no irritation after topical application. Conclusions Green tea extract based microsponges loaded in hyaluronic acid gel exhibited sustained drug release, anti-inflammatory effect and showed potential as a safe and effective topical formulation. Thus, green tea extract could be a potential herbal drug for the treatment of cutaneous lupus erythematosus and the developed formulation strategy poses a suitable formulation to treat CLE patients addressing the need for safer and more effective treatment. Graphical abstract