TABLE 2

Comparison of the fu measured by equilibrium dialysis, ultracentrifugation, and ultrafiltration at two different concentrations of microsomal protein

Values represent the mean ± S.D. of triplicate determinations.

Drug
fu
Equilibrium Dialysis
Ultracentrifugation
Ultrafiltration
1 mg/ml
0.2 mg/ml
1 mg/ml
0.2 mg/ml
1 mg/ml
0.2 mg/ml
Desipramine 0.21 ± 0.03 0.66 ± 0.15 0.29 ± 0.01 0.63 ± 0.03 0.31 ± 0.02 0.60 ± 0.04
Amitryptiline 0.53 ± 0.26 0.82 ± 0.08 0.25 ± 0.02 0.71 ± 0.04 0.31 ± 0.02 0.60 ± 0.04
Imipramine 0.48 ± 0.18 0.83 ± 0.28 0.75 ± 0.08 1.12 ± 0.11 0.50 ± 0.05 0.76 ± 0.04
Verapamil 0.53 ± 0.06 0.72 ± 0.19 0.67 ± 0.10 1.09 ± 0.11 0.60 ± 0.02 0.88 ± 0.06
Diltiazem 1.09 ± 0.42 0.96 ± 0.09 0.92 ± 0.02 1.14 ± 0.02 0.98 ± 0.04 1.10 ± 0.06
Propafenone 0.77 ± 0.08 0.98 ± 0.17 0.75 ± 0.08 1.12 ± 0.11 0.69 ± 0.07 0.98 ± 0.09
Chlorpromazine 0.15 ± 0.02 0.40 ± 0.12 0.27 ± 0.02 0.68 ± 0.01 N.D. N.D.
Midazolam 0.65 ± 0.08 0.98 ± 0.17 0.75 ± 0.08 1.12 ± 0.11 0.69 ± 0.08 0.98 ± 0.10
Diclofenac
0.89 ± 0.05
0.95 ± 0.03
0.62 ± 0.06
0.88 ± 0.06
0.61 ± 0.06
0.84 ± 0.04

  • N.D., not determined.