TABLE 9

Retro-reduction of oxycodone N-oxide by human liver microsomes (pH 10)

Values are expressed as means ± S.D., mean of four determinations, pH 10

Human Liver MicrosomeTime (min)OxycodoneOxycodone N-OxideNoroxycodoneOxymorphoneNoroxymorphone
min(nmol/ml)/mg proteinnmol/ml(nmol/ml)/mg protein
HK37a038.8 ± 2.2147.9 ± 2.55.3 ± 0.30.1 ± 0.001ND
1042.7 ± 4.5168.6 ± 14.66.4 ± 0.80.2 ± 0.04ND
2042.6 ± 1.9142.4 ± 8.36.2 ± 0.040.2 ± 0.01ND
HH18b06.5 ± 0.813.3 ± 2.20.9 ± 0.3NDND
106.8 ± 0.612.5 ± 2.21.0 ± 0.1NDND
209.4 ± 0.712.6 ± 5.51.4 ± 0.3NDND
  • ND, not detected.

  • a Oxycodone N-oxide was present at 200 µM.

  • b Oxycodone N-oxide was present at 20 µM.