Polymers are defined by patterns of repeating chemical structures called monomers. They are among the common constituents of both living and non-living matters on the planet. Perhaps, polymers are major inputs in pharmaceutical formulations and also in the new frontiers of nano-based drug/vaccine delivery systems. Most natural polymers, as such, are not however suitable for a number of applications unless their properties are tailored and tamed via certain modifications. Such modifications of polymers as part of developing robust pharmaceutical excipients have also traditionally targeted to reduce their noxious properties and annihilate in vivo toxicities. The book explored the fundamental aspects of starch-based polymeric cross-linking using food grade cross-linking agent. The cross-linked starch microparticles which were physico-chemically characterized and loaded with model drug demonstrated impressive drug-release-sustaining capability. Readers in the Pharmaceutical industry and researchers in the academia and specialized laboratories working on design and development of drug delivery systems are the main beneficieries of the this book.