2.4. So how does QbD differ from these other approaches, if at all?

It really does not differ very much from all of these other than simply combining all of them into a real shift of paradigms as how to develop and manufacture quality drug products in the pharmaceutical industry.

The only major difference is really that it sets up a holistic philosophy very much as claimed by the dimensions of integrated management of the St. Galler Management approach⁴² formally embedded into all hierarchical and organisational levels of an organisation. Therefore, rather than being simply Design for Six Sigma transferred to the pharmaceutical industry as suggested by ICH Q8 and the tool kit used for a science driven development, it requires embedding into the whole organisation supported by the PQS of ICH10 and the QRM of ICH Q9. QbD does link the whole value chain similar to TQM but requires an overhead structure of a PQS and further requirements for processes as described in the FDA’s validation guideline. There is even a further level of integration to consider, as QbD promotes the integration between the pharmaceutical industry and the regulatory authorities, who are strictly speaking also the company’s customers. QbD attempts to integrate the regulatory review and approval of new drugs by the authorities (FDA, EMA) with the integrated QbD approach of the company and as such integrates the approval of new drugs to QbD specific aspects ranging from clinically relevant specifications (e.g. biorelevant specification limits for dissolution testing) to risk based decisions for the submission of variations (e.g. changes of the manufacturing process within the Design Space) and even risk based pre-approval inspections based on a better understanding of the process by the inspector.⁴³

⁴² Bleicher K.; Das Konzept Integriertes Management; p 85-98
⁴³ Nasr; Implementation of Quality by Design (QbD); 2011