Tryptanthrin Nanoliposomal Lotion as a Corticosteroid-Free Strategy for Safe and Effective Treatment of Atopic Dermatitis

Atopic dermatitis is a chronic inflammatory skin disease characterized by dry skin, itching, and recurrent eczematous lesions. Although current therapeutic strategies are effective, their use is often limited due to adverse effects. Therefore, the development of safer and more effective alternatives is required. Tryptanthrin is a yellow-gold alkaloid compound with anti-atopic and various pharmacological activities. However, its poor aqueous solubility results in low topical bioavailability. A tryptanthrin-loaded liposomal lotion was developed using a design of experiments approach to improve topical delivery. The optimized formulation showed enhanced physicochemical stability and moisturizing properties, as well as improved drug release compared to free tryptanthrin. In human keratinocyte cells, the liposomal lotion exhibited lower cytotoxicity than the free tryptanthrin and demonstrated higher skin residual. In the DNCB-induced atopic dermatitis mouse model, the tryptanthrin-loaded liposomal lotion produced therapeutic effects comparable to or greater than those of 1.0% hydrocortisone, without inducing adverse effects such as skin atrophy. Overall, the tryptanthrin-loaded liposomal lotion is presented as a promising and safe strategy for the topical treatment of atopic dermatitis.