This talk discusses the QbD initiative from a particle technology perspective. The central technical requirement of a sound QbD strategy is to determine how ingredient properties and processing conditions determine product structure and performance. Since particles (both granules and powders) dominate the manufacturing of almost all pharmaceutical products, particle science and technology are therefore critical foundational components of the knowledge base needed for modern product and process design.

While the task ahead is conceptully clear, and much progress is under way, a number of gaps need to be addressed, including:

- Incomplete understanding of raw material properties

- Insufficient knowledge of effect of process variables across scales

- Lack of methods for characterizing structure of products and in-process materials

- Underdeveloped process monitoring tools

- Lack of control methodologies for powder-based processes

- Over-reliance on batch manufacturing methods

In this talk, these gaps are discussed, recent progress in addressing themis presented, and a way forward is outlined.