When I began my QbD journey, I was confused by the jargons that FDA or ICH used (or created) in their guidelines. After some time I understood it. But now I had to explain it to those who are new to Quality by Design. They were unimpressed due to ambiguous terminologies. At the time, my goal was to encourage more process characterization studies. So I translated the QbD framework to fit the lens of my scientist colleagues. It kind of works. So I share.
Quality by Design (QbD) Framework – in plain words (for scientists).
What QbD means to a scientist: This video explains the essence of ICH Q8 (R2) guideline in 2 minutes.
Let’s begin with the framework; here we have the framework of Quality by Design based on ICH, Q8 Revision 2. It starts with quality target product profiles QTPP and then it translates down to CQA’s; critical quality attributes and then that should be translated to CPP’s; critical process parameters. Now here is where we do a risk assessment and based on the risk assessment you would prioritize mapping out the design space based on high-risk items because you do not have the resources to map every design space, so if very selective about your design space.
And finally, the control strategy is what the manufacturer will do to keep the design space within the ranges that they promised in the monitoring plans and the plans to how to control them, how to change them and so forth. If you look in the scheme of the big things the quality target product profile I will call — Big Y and the CQA; critical quality attributes will be the y and the CPP, which are the critical process parameters I will call the X’s and the design space is where they marry the CQA and the CPP; ultimately to the QTPP’s and so they will be be the function that encompass multiple X’s, that translates to Y’s
So as you can see that the ultimate purpose of the quality by design is to first figure out what we need to focus on and what that relationship is and in this module we’ll focus on the relationship itself. So our ultimate goal is to get that Y equals F(X), to know what the CPP’s are; to know what the CQA’s are and how they relate to each other.
I know it’s not perfect. I’d like to get it down to 1 sentence. I need the community’s help.
Challenge: So how do you explain Quality by Design framework in one sentence?