Table 1.
Method (Conditions) | Association Equilibrium Constant(s) (M−1) | Reference |
---|---|---|
Capillary electrophoresis/frontal analysis (pH 7.4, 25°C) | R-Verapamil, Ka = 2.67 (± 0.44) × 103 | 23a |
S-Verapamil, Ka = 0.85 (± 0.11) × 103 | ||
Capillary electrophoresis/liquid pre-column (pH 7.4, 25°C) | R-Verapamil, Ka = 2.7 (± 0.44) × 103 | 21a |
S-Verapamil, Ka = 0.84 (± 0.16) × 103 | ||
Capillary electrophoresis/frontal analysis (pH 7.4, 25°C) | Racemic verapamil, Ka =1.69 (± 0.13) × 103 to 1.79 (± 0.70) × 103 | 22,24b |
Capillary electrophoresis/frontal analysis (pH 7.4, 25°C) | Racemic verapamil, Ka = 1.10 (± 0.03) × 103 | 28 |
Equilibrium dialysis (pH 7.4, 37°C) | Racemic verapamil, Ka= 1.16 × 105 and 6 × 103 | 29 |
The same authors working with apparently the same system report in Ref. 19 an essentially identical value for R-verapamil but Ka = 8.5 (± 0.1) × 103 M−1 for S-verapamil; this appears to be the result of a typographical error.
This range of values was obtained by using several data analysis methods for the same set of experimental results.