Solid lipid nanoparticles bearing flurbiprofen for transdermal delivery

Topical application of the drugs at the pathological sites offer potential advantages of delivering the drug directly to the site of action and thus producing high tissue concentrations of the drug. The solid lipid nanoparticles (SLN) bearing flurbiprofen were prepared by microemulsion method by dispersing o/w microemulsion in a cold aqueous surfactant medium under mechanical stirring. The SLN gel was prepared by adding SLN dispersion to polyacrylamide gel prepared by using polyacrylamide (0.5%), glycerol (10%), and water (69.5%). Shape and surface morphology was determined by scanning electron microscopy that revealed fairly spherical shape of the formulation. Percent drug entrapment was higher in SLN dispersion in comparison to SLN gel formulations. In vitro drug release, determined using cellophane membrane, showed that SLN dispersion exhibited higher drug release compared with SLN gel formulations. Both the SLN dispersion and SLN-gel formulation possessed a sustained drug release over a 24-hr period, but this sustained effect was more pronounced with SLN-gel formulations. The percent inhibition of edema after 8 hr was 55.51 +/- 0.26% in case of SLN-T4-gel, whereas flurbiprofen and SLN-T4 dispersion exhibited 28.81 +/- 0.46 and 31.89 +/- 0.82 inhibition of edema. The SLN-T4-gel not only decreased the inflammation to larger magnitude, but also sustained its effect.