||The aim of the current work was the formulation, characterization and in vivo study of betamethasone valerate nanoemulsion based on the induction of contact dermatitis in rats using a dispersion of nickel sulfate in solid vaseline at 5%, carragennen induce inflammation and their irritation study. Nanoemulsions were prepared by aqueous phase titration method, using sefsol, tween 20, transcutol P, and distilled water as the oil phase, surfactant, co surfactant and aqueous phase, respectively. Selected formulations were subjected to physical stability studies and consequently in vitro skin permeation studies. A surface study of optimized formulation was done by transmission electron microscopy. In vivo anti-inflammatory, In vivo irritation study and In vivo nickel induced contact dermatitis activity were done. The droplet size of nanoemulsion ranged from 150 to 200 nm. The optimized formulation exhibited viscosity 26.95 ± 1.71mP, refractive index 1.431, pH 6.5, and conductivity 10 -4 scm -1. The optimized nanoemulsion was converted into hydro gel using carbopol 934. Drug deposition in skin was found to be 58.46 μg/cm2. In vivo anti-inflammatory activity indicated 84.2% and 45.05% inhibition of inflammation in case of developed nanoemulsion gel (A5) and marketed cream, respectively. The irritation score was found to be 1.83 which indicates our optimized nanoemulsion was not cause any irritation. Result of nickel induced dermatitis demonstrate that the nanoemulsion formulation (A5) gel did not appear to stimulate an inflammatory or immune response using the contact dermatitis model.