Drug Delivery is a discipline that deals with both science and engineering issues concerning effective methods for introducing drugs into the human body. We are most familiar with the oral delivery method (swallow a pill). Insulin, a hormone, is far too fragile to be taken orally as our digestive system would hydrolyse it. It is important for us to know how the body takes up and eliminate drugs. A whole discipline deals with the mathematical treatment of these issues. It develops models for the effects of drugs on the body, and how the body handles a drug. The area is too vast to cover in-depth here. We will concentrate on a brief discussion of Pharmacokinetics followed by drug delivery technologies.