ABSTRACT
Drug research has evolved and matured through several phases beginning with the botanical phase of early human civilization, through the synthetic chemistry age in the mid-20th century, and finally the biotechnology era at the dawn of the 21st century. The advent of combinatorial chemistry and advances in high-throughput screening, functional genomics, and proteomics has expanded the therapeutic armamentarium to incredible levels. This definitely calls for an aggressive search for strategies to deliver these potent molecules. Conventional routes of administration — oral ingestion as well as IV
(intravenous) and IM (intramuscular) injections — distribute the drug molecule to all body parts, including targeted and nontargeted sites. This creates a burden on the whole-body system, while the requirement is only at a particular site in the body. In addition, conventionally delivered drugs become diluted in the blood and body fluids, resulting in an inadequate drug concentration at the diseased site while causing toxicity to healthy tissue. An attractive alternative for the delivery of these pharmacologically active compounds is regional/localized drug delivery.
