www.pall.com/biopharm
37
5.
Post-use Treatment of Cassettes and System
Once the TFF Process has been completed and the product recovered, the Omega membrane
cassettes can be cleaned and reused. There are several steps that must be followed to remove
remaining contaminants and return the cassettes to initial condition.
Figure 26
Sequence of Steps for Post-use Treatment of TFF Cassettes
The cleaning process should also be documented and validated if cassettes will be reused in production
of a biopharmaceutical product. This flushing and cleaning process takes considerable time and uses
substantial quantities of water and cleaning agent. It may be worth evaluating the economics of cleaning
and validation for reuse compared to discarding cassettes after a single use.
5.1
Flushing Cassettes after Use
Following a TFF process, the product, if in the concentrate, would have likely been recovered
by displacement with buffer followed by a recirculation and flushing with a small additional
volume of buffer. In this case, it may not be necessary to flush the cassette before adding
cleaning solution.
If the product was in the permeate, the concentrate should be flushed from the cassette using
water or buffer prior to introducing cleaning solution.
5.1.1
Flush the Feed/Retentate Line to Waste
Volume Required:
10 L/m
2
(1.0 L/ft
2
)
Direct the retentate and permeate lines to waste.
Figure 27
System Setup for Flushing to Waste
Step
5
Buffer
Condition
4
Determine NWP and
Membrane Recovery
3
WFI Flush
2
Clean-in-
Place
1
Buffer or
WFI Flush
Optimization or
Processing Mode
Retentate
Permeate
Feed
Tank
Waste
Waste
Feed
Pump
Pp
Rp
Fp
