Drug delivery is the technique of delivering drugs in the body for the desired results. The goal of drug delivery is to achieve a therapeutic outcome. Pharmaceutical drugs may either be consumed orally or injected into the living organism. This book discusses the fundamentals as well as modern approaches of drug delivery. The objective of the book is to give a general view of the different areas of drug delivery and its applications. As this field is emerging at a rapid pace, the contents of this book will help the readers understand the modern concepts of the subject.