The permeation study was performed using the modified Franz-diffusion cell apparatus following previously reported method.[15-18] The marketed cream, plain MF loaded gel and SLN loaded gel, all were studied for the permeation through rat skin. The receptor chamber with cross-sectional area of 4.32 cm2 was filled with receptor medium (ethanol:water 1:1). The gel or cream was applied uniformly on dorsal side of rat skin and donor compartment was placed. At set interval of 1-8 h, 0.5 ml of the sample was removed and immediately replaced by the equal volume of receptor phase solution. The amount of MF diffused into the receptor phase from the formulations was determined by UV spectrophotometer at 248 nm. By determining the cumulative drug permeated at various time intervals, the cumulative % of drug diffused versus time (in h) was plotted for plain MF loaded gel, MF-SLN loaded gel and also marketed cream.