Quality by design (QbD) in the formulation and optimization of liquid crystalline nanoparticles (LCNPs): A risk based industrial approach

The intersection of lipid-based nanoparticles and lyotropic liquid crystals has provided a novel type of nanocarrier system known as 'lipid-based lyotropic liquid crystals' or 'liquid crystalline nanoparticles' (LCNPs). The unique advantages and immense popularity of LCNPs can be exploited in a better way if the formulation of LCNPs is done using the approach of quality by design (QbD). QbD is a systematic method that can be utilized in formulation development. When QbD is applied to LCNPs formulation, it will proffer many unique advantages, such as better product and process understanding, the flexibility of process within the design space, implementation of more effective and efficient control strategies, easy transfer from bench to bedside, and more robust product. In this work, the application of QbD in the formulation of LCNPs has been explored. The elements of QbD, viz. quality target product profile, critical quality attributes, critical material attributes, critical process parameters, quality risk management, design of experiments, and control strategy for the development of LCNPs have been explained in-depth with case studies. The present work will help the reader to understand the nitty-gritties in the application of QbD in the formulation of LCNPs, and provide a base for QbD-driven formulation of LCNPs with a regulatory perspective.