Drug Discovery, Designing Chemistry and Pharmaceutical Analysis

Application of biopharmaceutical concepts to formulation development has revolutionized strategy for dosage form design. Nanotechnology has become an essential element of pharmaceutical sciences and fi nds multiple applications in drug delivery systems in enhancing therapeutic performance of drugs. Many of the current “Nano” drug delivery systems are pedigree of conventional dosage forms like Nano suspensions, Nano emulsions, and Nano micelles. Nano suspension is an approach to deliver water insoluble and poorly bioavailable drugs by reducing size to submicron range. Th ereby its dissolution rate is increased and hence the bioavailability, where drug dissolution rate is the limiting factor. Nano emulsions are O/W or W/O emulsion, having droplet size from 20-200 nm that are transparent and do not have the tendency to coalesce. Nano emulsions show great aesthetic appeal and skin feel and fi nd their application in transdermal delivery of drugs, topical application for systemic drug delivery, oral delivery of proteins and delivering drugs through parenteral and intranasal routes. Nano micelles are self-assembling Nano sized (usually with particle size within a range of 10 to 100 nm) colloidal dispersions with a hydrophobic core and hydrophilic shell. Th ese are currently used as pharmaceutical carriers for solubilizing hydrophobic drugs and provide drug delivery platform to be exploited for multiple routes of administration. All of these nano formulations combine the advantage of maximizing therapeutic benefi ts with minimized side eff ects and improved safety, since they have enormous potential of being targeted at cellular level. Th is review describes various facets of nano drug delivery systems in relation to formulation, characterization, potential benefi ts and risks, and pharmaceutical applications in drug delivery.