Figure 5
RP-UPLC-MALS and SEC-MALS of mAbs for long term stability studies. Typical chromatograms of the long-term-storage study, showing the regions of eluting sample. Top: RP-UPLC-MALS chromatograms; bottom: SEC-MALS chromatograms. Left: PPI10; right: PPI08. The Mw of the monomer, aggregates/fragments, and dimers are highlighted in blue, red and green, respectively. HMW stands for high-molecular-weight species, which are usually not separated, and in all our investigated cases presented no detectable UV signal. A magnified section shows the impurities for PP08. The shifting of the chromatograms at different time points is due to column ageing. PPI10 is shown in one formulation only (His 10 mM at pH 6.5), where the chromatograms before and after 6 months at 25 °C are depicted in black and red, respectively. PPI08 is shown formulated at pH 6.5 (His 10 mM) before stress, in black, and after 6 months at 25 °C, in magenta, and formulated at pH 5 (His 10 mM) before, in black, and after 6 months at 4 °C, in green, and 6 months at 25 °C, in red. PPI08 fragments are zoomed.
