ABSTRACT
This chapter describes the process of designing products with the end in mind. Many industries already employ the concepts of quality by design (QbD) in their manufacturing. The process analytical technology (PAT) guidance from the Food and Drug Administration has been the subject of much discussion and perhaps some misunderstanding. It was the first major guidance in the QbD thrust since the PAT guidance is an enabler for QbD. The generic industry operates under different time constraints than the branded industry. This is because at the time of abbreviated new drug applications filing, the generic company will not have had time to execute the procedural elements discussed. PAT is an enabler for QbD. It enables the use of scientific understanding as the basis for decision making, as opposed to blind regulation or convention, and requires the use of controls to rational endpoints rather than being arbitrarily controlled by time.
