The success of a spray drying process scale-up is vested in the detailed
knowledge and understanding of the parametric response and
inter dependability of variables. This makes QbD and PAT extremely
useful with respect to process transfer from a lab to a production
plant. Additionally, these tools also aid in avoiding material/product
wastage due to batch failure, increasing process efficiency and continuous
process improvement within the design space. QbD is described by
the United States Food and Drug Administration (US FDA) in its Guidance
for Industry: Q8 (R2) Pharmaceutical Development [217] as “A systematic
approach to development that begins with predefined
objectives and emphasizes product and process understanding and process
control, based on sound science and quality risk management”.
QbD involves defining CQA and critical process parameters (CPP)
through risk analysis and subsequent identification of their relationship
through design of experiment (DOE) approach [218]. DOE has been
used extensively in spray drying to understand the complex relationship
between various process parameters and its effect on product quality