Pharmaceutical Quality by Design (QbD) Overview and Major Elements

The risk-based approach initiative for pharmaceutical development initiated in 2004 by the Food and Drug Administration (FDA, USA) paved the way for the Quality by Design framework to be implemented in the pharmaceutical industry. Ever since, much work has been done; however, there is still a long way to go for its complete understanding and implementation. This chapter intends to discuss the need for the QbD methodology as well as provide an overview of its major elements. An illustrative example of direct compression has been created to elucidate the concepts of quality target product profile (QTTP), critical quality attributes (CQAs), and risk analysis (RA). The benefits of using design of experiments (DOE) within the context of QbD will be discussed, including the concept of design space. At the end, a regulatory overview with practical references will be provided.