Nanoemulsion Based Hydrogel Containing Omega 3 Fatty Acids as a Surrogate of Betamethasone Dipropionate for Topical Delivery
ABSTRACT The aim of the present study was to investigate the potential of nanoemulsion formulation for topical delivery of betamethasone dipropionate (BD) using fish oil (containing omega-3 fatty acids) as the oil phase. BD has anti-inflammatory, immunomodulatory and antiproliferative activity. However, its clinical use is restricted to some extent due to its poor permeability across the skin. So to increase its permeation across the skin, nanoemulsion based gel formulations were prepared and characterised. Fish oil was used as the oil phase and was also exploited for its anti-inflammatory effect along with BD in the treatment of inflammation associated with psoriasis. Nanoemulsion formulations were prepared by aqueous phase titration method, using fish oil, Unitop 100, PEG 400 and water as the oil phase, surfactant, co-surfactant and aqueous phase respectively. Furthermore, different formulations were subjected to physical stability and consequently evaluated for ex vivo permeation and in vivo anti-inflammatory study. The optimized nanoemulsion was converted into hydrogel-thickened nanoemulsion system (HTN) using carbopol 971 and had a viscosity of 98.67 ± 0.06 PaS. The optimized formulation had small average diameter (125 nm) with zeta potential of -39 mv which indicated good long-term stability. In vivo anti-inflammatory activity indicated 87.64% and 48.76% inhibition of inflammation for drug loaded and placebo formulation respectively. Assessment of skin permeation was done by ATR-FTIR, DSC and histopathology studies which indicated changes in the structure of epidermal membrane of skin.