ABSTRACT
This chapter describes the effect of particle size and zeta potential on drug delivery and targeting. It also describes different routes of drug administration and discusses specific characteristics of drug delivery systems for each specific route. The chapter explains targeted delivery systems to specific organs, tissues, and cells. Interfacial polymerization of a monomer almost always produces microcapsules, whereas solvent evaporation may result in microspheres or microcapsules, depending on the amount of drug loading. Complex coacervation uses the interaction of two oppositely charged polyelectrolytes in water to form a polymer-rich coating solution called a complex coacervate. Gelatin and gum arabic are primary components of most complex coacervation systems. Drug delivery systems can broadly be classified into two groups: macromolecular drug carrier systems and particulate carrier systems. The ability of a macromolar or particulate carrier system to deliver a drug to a target site depends on the following characteristics: molecular weight/size, surface charge, surface hydrophobicity, and presence of targeting ligands.
