Topical delivery of cyclosporine loaded tailored niosomal nanocarriers for improved skin penetration and deposition in psoriasis: Optimization, ex vivo and animal studies

Abstract

Psoriasis is a chronic disease treated using topical application of calcineurin inhibitors. However, due to physico-chemical nature of psoriatic stratum corneum, the topical drug delivery is very challenging. The present study aims to explore the potential of niosomes to improve the topical delivery of cyclosporine (penetration and deposition) for effective treatment of psoriasis. The niosomes-gel was prepared by film hydration method using cholesterol, Span 60 and Carbopol 940 (gelling agent). The factorial design (32) was applied to optimize the size (128 nm) and poly dispersibility index (PDI = 0.14) of niosomes by selecting cholesterol: Span 60 ratio at 160 mg: 313.6 mg and hydration time at 42.9 min. In ex vivo permeability studies (rat skin), the niosomes showed high permeation (50.57% in 24 h) in comparison to the cyclosporine suspension (10.13% in 24 h). The drug deposition study showed 59 fold increase in the cyclosporine deposition in the stratum corneum (SC) and the viable epidermis/dermis (VED) layers, which was further ensured by Coumarin 6 fluorescence microscopy. The histopathology and psoriasis area - severity index (PASI) scores in the imiquimod induced psoriatic plaque model showed significant drop in the scoring with niosomes. In conclusion, the optimized niosomes showed promising results to improve the cyclosporine penetration and deposition in the skin tissue for the effective treatment of psoriasis.