Principles of Quality-by-Design in Pharmaceutical Development

The Quality-by-Design (QbD) concept is 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 [ICH Q8 (R2)].

A key assertion of QbD is that quality is controlled not by simply testing the product, but rather that quality is built into the manufacturing process by design. This is achieved by a control strategy that is based on both product and process understanding.

Practical Implementation:

Stage 1 (Process Design) of the Process Validation Lifecycle is where Quality-by-Design implementation is facilitated.

Within this workflow there are multiple risk assessments and deliverables that should be met to develop a robust process and analytical control strategy. They are:

These deliverables and risk assessments form the basis of design of the product, establish critical quality attributes (CQAs) and process performance indicators (PPIs) of the process, identify process parameters, material attributes and raw materials with potential impact on CQA and PPIs, and ultimately classify process parameters, material attributes and raw materials as critical or non-critical. All together, these items coalesce to create a comprehensive control strategy for the life-cycle of a product. A comprehensive control strategy is derived from current product and process understanding, that assures process performance, and that a product of required quality will be produced consistently.

Final Thoughts:

A systematic approach like QbD can potentially facilitate continual improvement and innovation throughout the product life-cycle.