Table 1.
Mean (s.d.) oxybutynin and desethyloxybutynin pharmacokinetic parameters (n = 28) after the administration of the Oxy-XL and IR-Oxy formulations.
| Parameters (units) | Oxy-XL | IR-Oxy | Oxy-XL | IR-Oxy |
|---|---|---|---|---|
| R-Oxybutynin | S-Oxybutynin | |||
| Cmax (ng ml−1) | 1.14 (0.52) | 2.85 (1.52) | 1.96 (0.86) | 5.19 (2.97) |
| tmax (h) | 4.29 (2.33) | 1.20 (0.57) | 4.21 (3.19) | 0.93 (0.44) |
| Cmin (ng ml−1) | 0.32 (0.21) | 0.09 (0.06) | 0.59 (0.40) | 0.13 (0.10) |
| AUC (ng ml−1 h) | 18 (9) | 14 (6) | 31 (16) | 20 (9) |
| Ratio (90% CI)a | 126.9 (116.5, 138.2) | Reference | 153.0 (139.8, 167.3) | Reference |
| Degree of fluctuation (%) | 1.1 (0.3) | 4.5 (1.0) | 1.1 (0.3) | 6.0 (1.5) |
| Difference (90% CI)b | −75.2 (−82.0, −68.5) | Reference | −81.2 (−89.6, −72.8) | Reference |
| Bioavailability (%) | 131 (32) | Reference | 158 (39) | Reference |
| R-Desethyloxybutynin | S-Desethyloxybutynin | |||
| Cmax (ng ml−1) | 8.3 (2.97) | 30.29 (7.28) | 4.78 (2.37) | 15.24 (4.55) |
| tmax (h) | 5.78 (2.71) | 1.11 (0.39) | 5.71 (2.71) | 1.04 (0.30) |
| Cmin (ng ml−1) | 2.28 (1.38) | 0.92 (1.24) | 1.42 (1.06) | 0.40 (0.57) |
| AUC (ng ml−1 h) | 132 (56) | 217 (82) | 79 (43) | 100 (43) |
| Ratio (90% CI)a | 60.3 (55.6, 65.4) | Reference | 75.9 (70.6, 81.5) | Reference |
| Degree of fluctuation (%) | 1.2 (0.46) | 3.5 (0.8) | 1.1 (0.4) | 3.8 (1.0) |
| Difference (90% CI)b | −66.1 (−73.1, −59.0) | Reference | −71.3 (−79.8, −62.8) | Reference |
| Bioavailability (%) | 62 (16) | Reference | 78 (16) | Reference |
a
Confidence interval (CI) estimated with log transformed data.
b
Confidence interval (CI) estimated around difference which is calculated as [(Test −Reference)/Reference].