A quality by design study of the use of microfluidic nanoprecipitation for the generation of sub-100 nm drug nanocrystals

Although drug nanocrystals have attracted considerable interest within the pharmaceutical industry, there remain issues with the production of nanocrystals with a size below 100 nm. The aim of the present study is to develop a stable, reproducible Canagliflozin (CFZ) sub-100 nm nanosuspension system using microfluidic nanoprecipitation and Quality by Design (QbD) techniques. By means of the circumscribed central composite design (CCCD), critical parameters of the microfluidic nanoprecipitation process and nanosuspension formula tion components were optimised. Optimal CFZ nanosuspension with Z-average of 89.52 ± 3.30 nm, PDI of 0.12 ± 0.01 and drug content of 92.49 ± 0.03 % was successfully fabricated using Soluplus as a stabiliser. An increase in saturation solubility corresponding to approximately 250 times the value of the pure CFZ in water was noted. The optimised CFZ nanosuspension was solidified by freeze-drying and electrospraying. Overall, the study has demonstrated that by using a combination of microfluidics and QbD it is promising to generate stable sub-100 nm nanocrystals with high yield, and narrow size distribution and favourable stability.