Figure 3

Real-time 1D ¹H NMR spectra for pegfilgrastim at 37 °C in different buffers (a,b) formulation, (c,d) 0.5 × PBS, (e,f) DMEM. Shown are the overlays of three 1D ¹H NMR spectra for pegfilgrastim amide region peaks (a,c,e) or PEG peak (b, d and f) in these conditions at 1 h (red), 20 h (green) and 43 h (blue).