TABLE 3

Concentrations of oxycodone HCl metabolites in human liver microsomal samples incubated with 200 µM oxycodone HCl at pH 7.4

Values are expressed as means ± S.D.

Human Liver MicrosomeTimeOxycodoneOxycodone N-OxideNoroxycodoneOxymorphoneNoroxymorphone
minnmol/ml(nmol/ml)/mg protein
HK37a0197.45 ± 5.160.20 ± 0.110.25 ± 0.010.04 ± 0.010.011 ± 0.015
10196.95 ± 7.140.33 ± 0.0031.73 ± 0.050.67 ± 0.05ND
20195.45 ± 7.140.36 ± 0.071.70 ± 0.030.63 ± 0.040.013 ± 0.018
HH18b0178.93 ± 9.680.24 ± 0.090.24 ± 0.070.02 ± 0.0030.014 ± 0.02
10165.60 ± 7.660.29 ± 0.050.69 ± 0.080.06 ± 0.003ND
20163.70 ± 5.070.29 ± 0.071.69 ± 0.350.13 ± 0.01ND
  • ND, not detected.

  • a CYP3A4 activity was 2.5 (nmol of product/min)/mg protein in the testosterone 6β-hydroxylase assay. FMO activity was 3.6(nmol of product/min)/mg protein protein in the methyl p-tolyl sulfide oxidase assay.

  • b CYP3A4 activity was 12.0 (nmol of product/min)/mg protein in the testosterone 6β-hydroxylase assay. FMO activity was 2.8 (nmol of product/min)/mg protein in the methyl p-tolyl sulfide oxidase assay.