The quality of pharmaceutical products is the top priority for both biopharmaceutical companies and regulators. To ensure consistently high product quality and improve the efficiency of manufacturing and regulation, the US FDA introduced quality by design (QbD) to the pharmaceutical industry in its 2002 Pharmaceutical CGMP initiative, Pharmaceutical CGMPs for the 21st Century: A Risk-Based Approach (1). Since the introduction of QbD, the FDA has taken multiple measures to promote industry-wide implementation, but the industry’s response to QbD has been…