ABSTRACT
Quality by design has been both a development and regulatory objective since the turn of the Millennium. Inhaled medicines are complex products for which each component requires scrutiny with respect to impact on the important performance measures of delivered dose and aerodynamic particle size. The compounding of error arising from any variability in the active pharmaceutical ingredient, the formulation, the metering system, the device, and any auxiliary attachments, requires exquisite control if performance is to be maintained within reasonable limits. This chapter considers the target product profile on which development is based, the critical quality attributes that must be monitored and controlled, and concludes with risk management and assessment that derive from an understanding of a specific process and product. All factors can then be used as the foundation for lifecycle management and continual improvement to the product.
