This issue discusses drug delivery and how advances in the pharmaceutical sciences and other scientific fields have enabled substantial progress in this field. Targeting the best route or providing a variety of routes of drug administration presents an array of benefits, such as enhanced drug administration and bioavailability, improved patient acceptance and compliance, decreased toxicity, and precise therapeutic targeting. Technologies enabling drug delivery are now commonly used to create and extend markets, and the pharmaceutical industry is turning to drug delivery to extend the revenueearning lifetime of their biggest products. Growth opportunities for drug delivery systems extend into all therapeutic classes of pharmaceuticals and encompass a wide range of compounds and formulations, presenting many options in the world market. The discovery of better delivery systems in conjunction with the discovery of novel pharmacological compounds will advance disease diagnosis and treatment.