What is Quality by Design (QbD)?

The pharmaceutical Quality by Design (QbD) 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.

QbD wheet for understanding component and phases of QbD.

Objectives of QbD

• To achieve meaningful product quality specifications that are based on clinical performance
• To increase process capability and reduce product variability and defects by enhancing product and process design, understanding, and control
• To increase product development and manufacturing efficiencies
• To enhance root cause analysis and postapproval change management

QbD approach in pharmaceutical industry

In a pharmaceutical QbD approach to product development, an applicant identifies characteristics that are critical to quality from the patient’s perspective, translates them into the drug product critical quality attributes (CQAs), and establishes the relationship between formulation/manufacturing variables and CQAs to consistently deliver a drug product with such CQAs to the patient. QbD consists of the following elements:

• A quality target product profile (QTPP) that identifies the critical quality attributes (CQAs) of the drug product
• Product design and understanding including the identification of critical material attributes (CMAs)
• Process design and understanding including the identification of critical process parameters (CPPs) and a thorough understanding of scale-up principles, linking CMAs and CPPs to CQAs
• A control strategy that includes specifications for the drug substance(s), excipient(s), and drug product as well as controls for each step of the manufacturing process
• Process capability and continual improvement

Conclusion

The goals of implementing pharmaceutical QbD are to reduce product variability and defects, thereby enhancing product development and manufacturing efficiencies and postapproval change management. It is achieved by designing a robust formulation and manufacturing process and establishing clinically relevant specifications. The key elements of pharmaceutical QbD can include the QTPP, product design and understanding, process design and understanding, and scale up, control strategy, and continual improvement. Prior knowledge, risk assessment, DoE, and PAT are tools to facilitate QbD implementation. Finally, product and process capability is assessed and continually improved postapproval during product lifecycle management.