Continuous ILDF Buffer Consumption
Another means of evaluating the continuous ILDF process versus the batch
process involves comparing buffer consumption. Buffer consumption, in
this case, included the buffer needed for the initial dilution of the
starting liposome formation mixture as well as that needed to perform
the diafiltration to the target ethanol concentration. Figure 5 shows
the buffer consumption (dilution and diafiltration) for theoretical
batch processes of equivalent scale with rejection coefficients of 0 and
0.5 (the approximate value of previously calculated batch scenario) and
compares them to the continuous ILDF model used to generate the results
in Figures 4B. Surprisingly, the continuous ILDF set up is in line with
the zero rejection coefficient batch process. Previous evaluations of
similar set ups in the realm of biologics have shown continuous designs
to require more buffer than batch (Kavara, et al. 2020, Jabra, et al.
2019). The Figure 5 results again show how the use of independent
passes/stages offsets the impact of ethanol on the hollow fiber
permeability.