It seems that Quality by Test is well on its way to being a thing of the past, and for good reason. With only one out of every 10 drug products actually making it to market (1), it is no surprise that pharma companies are increasingly eager to adopt measures to ensure quality and manage risk. Quality by Design (QbD) continues to be a hot topic across the life science industries, and as evidenced by the widespread adoption of QbD among manufacturers, there is no question about its benefits.
“The main issue with late-stage quality analysis is that it only detects and removes substandard products – it doesn’t prevent them from being created in the first place,” according to a recent PharmTech article on pharmaceutical QbD (2). “As pharmaceuticals become increasingly complex, it’s more important than ever that quality is designed into the products from the initial concept to ensure patient safety.”
As the pharma sector moves to implement pharmaceutical QbD, regulatory bodies such as the FDA work to provide a common understanding of key concepts, terminology and expectations. This article reviews the current understanding of pharmaceutical QbD and its primary elements.
Establishing a definition of pharmaceutical quality is really the first step to incorporating it into the design and development of drug products, and as with most industry terms, it can be challenging to reach a consensus. Quality in general terms can be defined as products that meet scientifically derived product and process performance objectives, while exhibiting minimal variation within each batch and from one batch to another (3). More specific to pharma, ICH Q8 defines quality as the suitability of either a drug substance or drug product for its intended use (4). The director of the Center for Drug Evaluation and Research (CDER), Janet Woodcock, offers a similar yet more nuanced definition: a high-quality drug product as one that is free of contamination and reliably delivering the therapeutic benefit promised in the label to the consumer (5).
Unlike the empirical-based methods used in traditional product development and manufacturing methods, QbD is a scientific, risk-based approach that focuses on designing quality into a product from the earliest stages of planning to prevent quality failures from ever occurring and more readily address them if they do occur (6). Many companies practice different interpretations and variations of QbD (7), but most can agree that it comes down to fully understanding and controlling all aspects of the manufacturing process as they pertain to the critical quality attributes of a drug product (collectively known as the Design Space (4)). In addition to achieving a safer and more effective product, QbD affords more regulatory flexibility with respect to the Design Space, all of which translate into direct cost benefits for producers.
What these definitions have in common is a focus on achieving a reliably safe and effective end product to deliver better patient outcomes, providing obvious benefits to both consumers and pharma companies alike. Thus, the question drug makers are asking about QbD is not so much why, but how.
Knowing the theory and benefits behind the concept of QbD is a critical step toward implementing it. And to bridge the gap between theory and practice, ICH Q8 along with other research initiatives have given us a solid starting point for implementation. Below are the key elements of a QbD program (9):
Because pharmaceutical QbD requires considerable resources (time, money, personnel, expertise, etc.) to implement, it gained momentum initially among big pharma companies (10). But QbD is now on the rise among forward-thinking companies of all sizes, particularly as the required knowledge, technology and tools become more established and widely available. Despite efforts she and others have already made to further our understanding of pharmaceutical quality, Woodcock believes there is still work to be done in the area of QbD.
“Actually, we defined the quality of a pharmaceutical product a long time ago: fitness for use,” Woodcock stated in a Pharmaceutical Online article (11). “It delivers the properties described on the label and is not contaminated. But the other piece is, what is quality in manufacturing? And that’s really what we are focusing on. Right now, a lot of the industry delivers quality products by throwing away, by wasting, up to 35 percent of what’s produced, and we don’t believe that amounts to quality manufacturing. We’ve been exploring this question extensively with industry in a very open process: ‘What metrics might we use that would measure the quality of your manufacturing processes?’”
But what we do know is that the FDA, EMA and other key regulatory authorities support a risk-based approach and the inclusion of QbD principles in the development and production of drug products. QbD is also thoroughly addressed in the latest ICH Quality Guidance documents Q8 to Q11, each covering different aspects of the concept. So while some questions may remain, QbD is clearly here to stay.
Beth Pedersen is a content marketing specialist at the MasterControl headquarters in Salt Lake City, Utah. Her technical and marketing writing experience in the enterprise software space includes work for Microsoft, Novell, NetIQ, SUSE and Attachmate. She has a bachelor’s degree in life sciences communication from the University of Wisconsin-Madison and a master’s degree in digital design and communication from the IT University of Copenhagen.