1996; Lewis 2002; Singh et al. 2005b, 2011b). Fig. 18.8 illustrates such interrela-

tionship among the possible explorable, knowledge, design and control spaces. A

more stringent domain is carved out of design space for further studies in an

industrial setup.

For assuring the best possible as well as economical nanoformulation production,

a design space is ideally generated based on the basis of experimentation at lab and

pilot plant scales, which is then re-examined at an exhibit and commercial scales

(Araujo and Brereton 1996; Lewis et al. 1998; Montgomery 2001; Singh et al.

2018a). From a regulatory angle, a formulation lying in the boundaries of the design

space is only federally acceptable. Any movement within the design space is

federally acceptable, and no further investigation is required. On the other hand,

movement outside the design space calls for resubmission for its regulatory

approval. On the other hand, movement outside the design space calls for resubmis-

sion to the federal agency for approval. Subsequent to the design space approval, a

narrower working range, as per the customized specifications by the manufacturer

called as control space, is embarked upon (Singh et al. 2013; Danhier et al. 2017). On

Fig. 18.8 Comprehending

relationship among

explorable, knowledge,

design and control spaces

18

QbD-Steered Systematic Development of Drug Delivery Nanoconstructs:. . .

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