To determine the anti-inflammatory activity of the formulations prepared, carrageenan-induced hind paw edema test was performed . Twenty rats were divided into four groups, one being the untreated control. Commercial cream, Na-DOC Gel and nanoparticle colloidal suspension incorporated in chitosan gel (NP) were applied to the plantar surface of the rat hind paw at a fixed CP dose of 0.125 mg/cm2 for one hour, before the induction of inflammation. In order to produce inflammation, 50 µL of a 1% (w/v) solution of λ carrageenan in saline was injected into the plantar side of the right hind paw of rats. The contralateral paw received the same volume of sterile saline. The paw thickness (indication of edema) was measured using digital micrometer (Mitutoyo Corp., Kawasaki, Japan) before carrageenan injection and then after 1, 2, 3, 4 and 5 h. The % of increase in the paw thickness was calculated as the difference between the values obtained in right and left paw expressed as percentage. The obtained values were reported as a function of time after carrageenan injection; from the graph, AUC was calculated using Kaleidagraph software (Version 4.01, Synergy Software, Reading, PA, USA). The percentage of inhibition of carrageenan-induced paw edema was then calculated according to the Equation (1) presented above: (1)%Inibition=AUCC−AUCfAUCC×100 where AUCC is the average area under the curve of the control rats (no treatment) and AUCf is the area under the curve of the rats treated with the different formulations.