This is the essential guide to the study of absorption, distribution, metabolism and elimination of drugs in the body. Pharmacokinetics and biopharmaceutics courses have been included in pharmacy curricula in the USA and Europe for several years. Pharmacokinetics is the study of absorption, distribution, metabolism and elimination of drugs in the body. Pharmacists must understand this to ensure appropriate drug regimen for patients. The scope and the intent of this textbook is to provide the reader with a basic intuitive understanding of the principles of pharmacokinetics and biopharmaceutics and how these principles, along with the equations presented in each chapter, can be applied to achieve successful drug therapy. The application of pharmacokinetics principles and equations are illustrated by providing the reader with data available in the literature. As pharmacokinetics is basically mathematical in nature, a chapter has been included to provide the reader with a basic review of the mathematical principles and graphing techniques necessary to understand pharmacokinetics. At the start of each chapter, important objectives are listed to accentuate and identify the key points of the chapter. When an important and clinically applicable equation appears in the text, a paragraph will follow explaining the significance and therapeutic applications of that equation. Additionally, this paragraph includes and explains relevant factors influencing parameters in an equation. When applicable, at the end of an important equation, a general profile illustrating the relationship between the two variables of an equation will be presented. This approach should make the subject matter much more accessible to the student. Each chapter concludes with related problem sets and problem solving exercises for the student to work through. This should enable the reader to become more adept at solving pharmacokinetic problems arising in drug therapy and understanding the applications and utility of equations in clinical pharmacokinetics and practice. As you can see from the contents, the book is organised into eighteen chapters, the first consists of mathematical principles necessary to understand pharmacokinetics and an overview of the subject matter. The remaining chapters are organised in an order which should be easy for the reader to follow. Clearance and other essential fundamental pharmacokinetic parameters are introduced early in the book as the student will need to apply these concepts in subsequent chapters. A uniform set of notation will be adopted throughout the textbook (a table of which will be at start of the book).