Nanotechnology has potential in the development of novel and effective delivery of drugs within lungs. Different strategies have been utilized for pulmonary delivery of drugs, including the use of lipid-based delivery systems (liposomes, ISCOMs, SLNs), use of polymeric matrix (PLGA, poly caprolactone, cynoacrylates, gelatin), development of polysaccharide particulates (chitosan, alginates, Carbopol, etc.), biocompatible metallic inorganic particles (iron, gold, zinc), etc. This paper reviews various nanopaticulate approaches in the form of lipids, polymers, metals, polysaccharides, or emulsions based for pulmonary drug delivery that could provide an increased biological efficacy and better local and systemic action.

Abstract. The purpose of the research is to carry out systemic optimization of protocells (liposomes entrapped with silica particles). Optimization was carried out using 3 2 factorial designs for the selection of the optimized protocell composition with reference to particle size distribution and zetapotential. This design was carried out to study the effect of independent variables such as molar ratio of phosphatidylcholine to cholesterol and concentration of silica nanoparticles. A total of nine formulations of protocells were prepared and analyzed using Design expert® software from Stat-Ease, Inc. (Version 8.0.4.1 trial 2010) for the selection of the optimized combination. Contour plots were constructed with independent variables like size and potential. Protocell with 7:3 ratio of phosphatidyl choline to cholesterol and 0.5 mg/ml of silica nanoparticles demonstrated better colloidal behaviors. The findings obtained from the software corresponding to independent variables demonstrated accurate means for the optimization of the pharmaceutical formulations.