Particle Count Analysis by Coulter Counter of mAb A Formulation Mixed in Small-Scale Study Using Various Stir Bar Designs (200 mL Solution in 500 mL Glass Flask or Beaker under 180 rpm for up to 2 h)
| Particle Count (particles/mL) | Change in SvP Relative to t = 0a | |||
|---|---|---|---|---|
| Stir Bar Type | 0 h | After 1 h Mixing | After 2 h Mixing | |
| Standard Stir Bar (SB1) | 2.06 × 103 | 6.82 × 105 | 8.44 × 105 | 410 |
| Stir Bar with Ring (SB2) | 2.06 × 103 | 1.21 × 105 | 1.80 × 105 | 87 |
| Stir Bar on a Tri-Stand (SB3) | 1.70 × 104 | 6.17 × 104 | 1.33 × 105 | 8 |
| Top-Entry Stir Bar (SB4) | 4.34 × 103 | 9.00 × 103 | 1.04 × 104 | 2 |
↵a Change in SvP relative to t = 0: average particle count after mixing for 2 h ÷ average particle count in mAb A at t = 0.