Advances in biotechnology and molecular biology have resulted in a large number of novel molecules with the potential to revolutionize the treatment and prevention of disease. However, such potential is severely compromised by significant obstacles to delivery of these drugs in vivo. These obstacles are often so great that effective drug delivery and targeting is now recognized as the key to the effective development of many therapeutics. Additionally, advanced drug delivery and targeting can offer significant advantages to conventional drugs such as increased efficiency, convenience, and the potential for line extensions and market expansion. This is an introduction to the principles of advanced drug delivery and targeting, their current applications and potential future developments.