Material and method: Various protein characterisation methods: size exclusion chromatography (SEC), dynamic light scattering (DLS) describing submicronic populations and corresponding mean diameters, turbidity (350 nm) and infra-red spectroscopy (FTIR) were used to determine changes in physical properties of Rituximab aggregation mechanically induced. Several conditions were tested: presence of residual air in bags, travel time, number of travel cycles (1 to 8). One concentration was tested (1 mg/mL). All experiments were performed on the same day.

Results and discussion: Up to 8 travel cycles and without head space or bubbles into the bags, no modification was noticed in comparison with the control (no run). Indeed, we observed only one peak by SEC, a monodisperse population (polydispersity index < to 0.1) of 11.34 + 0.03 nm by DLS, a slightly increased of optical densities (OD) at 350 nm (0.0019 up to 0.004) and no modification of the FT-IR spectra (similarity coefficients were close to one). In the opposite, in presence of air, significant modifications were found after 4 cycles since OD reached to 0.007 and 2 populations were found by DLS with a polydispersity index of about 0.24. Moreover, modifications of FTIR spectra were also observed (similarity coefficient < 1) suggested alteration of the secondary structure. These results demonstrate that aggregation during the pneumatic is strongly dependant on the presence of air/ liquid interfaces.

Conclusion: In practice, a pneumatic system can be safely used for the transport of diluted rituximab (and probably other mAbs), but the presence of air into the bags must be avoided.