| # | Glycopyrrolate | Methylparaben | Propylparaben |
| 1 | 99.5 | 99.1 | 99.5 |
| 2 | 98.7 | 99.9 | 97.9 |
| 3 | 98.3 | 98.9 | 97.9 |
| 4 | 98.1 | 98.7 | 99.8 |
| 5 | 99.6 | 98.8 | 99.0 |
| 6 | 98.6 | 99.9 | 98.4 |
| Mean | 98.8 | 99.2 | 98.8 |
| SD | 0.6 | 0.5 | 0.8 |
| %RSD | 99.5 | 99.1 | 99.5 |