Table 3.
In vivo CNS penetration of various antimuscarinic agents in rats following subcutaneous administration
| Compound | fup : fub | Brain : plasma concentration ratio | Kp,free | CSF : free plasma concentration ratio |
|---|---|---|---|---|
| Trospium | 3.8 | 0.03 | 0.01 | 0.004 |
| 5-HMT | 4.5 | 0.16 | 0.04 | 0.04 |
| Darifenacin | 3.9 | 0.08 | 0.02 | 0.06 |
| Solifenacin | 11 | 3.04 | 0.28 | 1.41 |
| Tolterodine | 13 | 2.95 | 0.23 | 0.16 |
| Oxybutynin | 1.9 | 6.27 | 3.30 | 1.66 |
| N-methylscopolamine | 2.4 | 0.05 | 0.02 | 0.01 |
| Scopolamine | 1.8 | 3.42 | 1.90 | 1.13 |
Definition of terms: fub, unbound fraction in brain; fup, unbound fraction in plasma; Kp,free, ratio of unbound concentrations in brain : plasma.