Table 2.
Specific surface areas of lyophilized formulations, atom percent N in the outmost 100 Å layer of lyophilized formulations and the mass fraction of protein in that layer.
| SSA (m2/g) | N% | Surface rhGH Fraction, % |
||
|---|---|---|---|---|
| Standard lyophilization | 5% HES | 2.3±0.2 | 1.4±0.2 | 10.2 |
| 5% trehalose | 1.6±0.1 | 0.6±0.1 | 3.1 | |
| 5% sucrose | 1.2±0.1 | 0.7±0.1 | 2.7 | |
| Pre-drying annealing | 5% HES | 1.8±0.1 | 1.4±0.1 | 8.0 |
| 5% trehalose | 0.8±0.1 | 0.6±0.1 | 1.5 | |
| 5% sucrose | 0.8±0.1 | 0.7±0.1 | 1.8 | |
| Post-drying annealing | 5% HES | 2.3±0.2 | 1.2±0.2 | 8.8 |
| 5% trehalose | 1.3±0.1 | 0.4±0 | 1.7 | |
| 5% sucrose | 1.2±0.0 | 0.5±0.1 | 1.9 | |
| N2-immersion | 5% HES | 6.0±0.5 | 1.5±0.2 | 28.6 |
| 5% trehalose | 2.6±0.3 | 0.9±0.1 | 7.5 | |
| 5% sucrose | 2.7±0.3 | 0.8±0.1 | 7.0 | |
| N2-droplet-freezing | 5% HES | 6.2±0.5 | 1.6±0.2 | 31.5 |
| 5% trehalose | 3.0±0.2 | 0.9±0.1 | 8.6 | |
| 5% sucrose | 2.9±0.3 | 0.9±0.1 | 8.3 | |