Quality by design (QbD) approach for design and development of drug-device combination products: a case study on flunisolide nasal spray

The objective of the present study was to design and develop drug-device combination product in particular flunisolide nasal spray (FNS) using quality by design (QbD) approach. Quality target product profile (QTPP) of FNS was defined and critical quality attributes (CQAs), i.e. viscosity (cp) (Y1) and D50 droplet size distribution (DSD) (μm) (Y2) were identified. Potential risk factors were identified using a fish bone diagram and failure mode...