Thaw at room temperature with the Celsius FFT 6 L standing flat on a bench was also tested. Thaw profile at room temperature
is shown in Figure 5. It took 13.5 h to bring all the thermocouples from –45 °C to at least +2 °C with an average ambient
temperature of 20 °C.
The relatively rapid freeze-and-thaw kinetics observed with Celsius FFT are largely caused by specific design features of
the protective shell shown in Figure 1 and Figure 6. The shell provides large peripheral venting holes and recessed, partially
open, top and bottom surfaces. These features are favorable for unhindered heat transfer fluid circulation (cold air or hot
water) between stacked shells and exposure of the bag surface to the process temperature.
In addition, the small thickness of the shell and the bag film, the low thermal mass of the container itself, and the relatively
small freezing distance are favorable for rapid freeze-and-thaw kinetics.
Table 2: Results of the physical challenge tests with the Celsius FFT 6 L
The results of the physical challenge test are summarized in Table 2. The acceptance criteria used to assess the results of
the physical challenge tests are summarized in Table 3.
Table 3: Acceptance criteria of the physical challenge test
These physical challenge conditions selected for the Celsius FFT 6 L exceed the requirements defined in ISO 15747 for an infusion
container. The Celsius FFT 6 L containers withstood the physical challenge test with no evidence of leakage. The results confirm
that the flexible freeze-thaw system provides a simple and efficient method for handling frozen solutions without compromising
the container integrity and the product quality.
Nicolas Voute is a global product manager for fluid management technologies at Sartorius Stedim Biotech S.A., Aubagne, France, firstname.lastname@example.org