Nanotechnology: Science, Innovation, and Opportunity

Chapter 16. Drug Delivery

Jianjun Cheng and Suzie Hwang Pun

Therapeutic drugs are usually delivered in bolus doses, either orally or by injection. These administrations result in initial blood concentrations that are higher than required levels, followed by a decrease to subtherapeutic levels due to drug degradation and excretion. Therefore, drugs must be given frequently to maintain therapeutic drug concentrations (Figure 16-1). In the 1970s, researchers introduced the concept of controlled drug delivery by using carriers to release drugs in a sustained manner. In the ideal case, drugs are gradually released from a depot so that the drug concentration is maintained at an effective level over a long period. An example of one such success is Gliadel, ...