FACTORIAL DESIGN BASED OPTIMIZATION AND IN-VITRO - EX-VIVO EVALUATION OF CLOBETASOL LOADED NANO STRUCTURED LIPID CARRIERS

The aim of the present work was to develop and evaluate the potential of nanostructured lipid carriers (NLCs) loaded with Clobetasol-17-propionate (CP) as a new approach for the topical treatment of psoriasis. CP-loaded NLCs were prepared by melt emulsification and ultra-sonication method and optimized using 3(3) full factorial designs (Design-Expert software 11.0), by using solid lipid (compritol ATO 888) and liquid lipid (oleic acid) and Tween 80 as a surfactant. Drug loaded NLCs were evaluated for various parameters like particle size, surface charge, polydispersity index, entrapment efficiency, surface morphology, thermal analysis, in vitro drug release through the skin (Franz diffusion cell), drug deposition study and stability. The optimized formulation has a particle size of 91.2 +/- 2.37 nm, the zeta potential of -34.7 +/- 1.49 mV, polydispersity index of 0.173 +/- 0.035 and entrapment efficiency of 85.4 +/- 2.89%. Release study demonstrated prolonged CP release from NLCs following Higuchi release kinetics with r(2) = 0.9838, while pure CP suspension showed quicker drug release obeying zero-order kinetics with r(2) value of 0.9904. Skin permeation study of CP loaded SLNs suspension showed prolonged drug release up to 24 h. The maximum ex vivo drug deposition was obtained after developing the drug into NLCs (51.23 mu g/ml) when compared to the pure drug (18.34 mu g/ml). The prepared NLCs based formulation has proved to be a promising carrier system for the treatment of psoriasis.