The rise and rise of drug delivery.

Drug delivery has typically focused on optimizing marketed compounds, improving their effectiveness or tolerability, and simplifying their administration. This role now includes the first biopharmaceuticals as well as more conventional drugs. As drug-delivery technologies come into play earlier in the development cycle, however, they can also enhance the screening and evaluation of new compounds and 'rescue' failed compounds, such as those with low solubility. In this article, we look back at how the burgeoning field of drug delivery came into being and describe approaches for future discovery and development.