Niosomes or non-ionic surfactants vesicles are microscopic lamellar structures formed on the admixture of a non-ionic surfactant, cholesterol and phosphate with subsequent hydration in aqueous media. The delivery of drugs by “vesicular drug delivery system” such as niosomes provides several important advantages over conventional drug therapy.
The main objective of this study was to design suitable niosome-encapsulated drug delivery for anti-inflammatory drugs like nimesulide and evaluate the vesicle size, encapsulation efficiency, in vitro release and physical stability of the system. Non-ionic surfactants used were span 20, 40, 60 and cholesterol was used in different molar ratios. The niosomes prepared by lipid film hydration method were multilamellar vesicles (MLVS) and niosomes prepared by ether injection technique were unilamellar vesicles (ULVS) or oligolamellar vesicles. The higher entrapment efficiency was observed with MLVS prepared from span 60 and cholesterol in an 80:70 molar ratio. The in vitro diffusion study suggests that higher entrapment efficiency was related with slow release comparatively. The release pattern shown by these formulations were zero order & Higuchi diffusion controlled mechanism. The physical stability study show that niosomal preparation stored at refrigerated temperature for 60 days show maximum drug retained for all the formulation compare to room temperature and elevated temperature conditions. Finding of all this investigation conclusively demonstrate prolongation of drug release at a constant and controlled rate after niosomal encapsulation of nimesulide.[PDF] |