Correlation summary of radiometric HPLC and HPLC MS peaks characterized in human excreta
| Metabolite or Peak | Name | 14C Retention Time | MH+ | MS Retention Time | Lowest/Highest Individual % of Dose* | No. patients with 14C peak4-a | Metabolite or Artifact |
|---|---|---|---|---|---|---|---|
| min | min | ||||||
| M1 | SN-38N-oxide | 5.1–5.3 | 409 with 393 fragment | 6.05 | N.D. /0.43 | 4 /8 | Radioimpurity or metabolite |
| M2 | Unknown | 6.0–6.5 | N.D. /0.12 | 4 /8 | Unknown | ||
| M3 | SN-38 glucuronide | 7.4–7.8 | 569 | 8.11 | 2.54 /4.68 | 8 /8 | Major Metabolite |
| M4 | Unknown | 8.6 | N.D. /0.57 | 4 /8 | Unknown | ||
| M5 | CPT-11 hydroxy acid | 9.9–10.3 | 605 | 9.12 | 0.13 /0.38 | 8 /8 | Parent-equilibrium artifact |
| M6 | Unknown | 10.9 | N.D. /0.02 | 1 /8 | Unknown | ||
| M7 | Unknown | 11.3–11.6 | 0.34 /2.0 | 8 /8 | Unknown | ||
| M8 | Hydroxy CPT-11 | 11.9–12.9 | 603 | 11.01 | 0.02 /0.53 | 8 /8 | Possible metabolite in bile |
| M9 | Primary amine (NPC) | 12.9–13.6 | 519 | 11.24 | 0.22 /2.66 | 8 /8 | Metabolite |
| M10 | Hydroxy CPT-11 | 13.6–14.2 | 603 | 12.27 | 0.04 /0.97 | 8 /8 | Possible metabolite |
| M11 | APC | 14.3–15.1 | 619 | 12.53 | 6.19 /14.01 | 8 /8 | Major Metabolite |
| M12 | Hydroxy CPT-11/Lokiec 74-b | 16.6 | 603 | 14.39 | N.D. /0.11 | 2 /8 | Impurity |
| PDP-14-c/Lokiec 6 | 561 | 13.45 | N.D. /N.D. | 0 /8 | Impurity-MS only | ||
| M13 | Lokiec 154-b | 17.1–17.4 | 491 | 15.45 | N.D. /0.33 | 2 /8 | Degradation artifact of NPC or metabolite of impurity M14 |
| M14 | PDP-2/Lokiec 54-b | 17.8 | 559 | 16.38 | N.D. /0.37 | 4 /8 | Impurity/degradation artifact |
| CPT-11 | 18.4–19.7 | 587 | 17.10 | 45.39 /63.06 | 8 /8 | Parent Drug | |
| M15 | Unknown | 20.1–21.0 | N.D. /0.18 | 2 /8 | Unknown | ||
| M16 | Unknown | 21.0–22.0 | N.D. /0.14 | 1 /8 | Unknown | ||
| M17 | SN-38 | 22.0–23.5 | 393 | 21.41 | 6.19 /12.7 | 8 /8 | Active metabolite |
| M18 | Unknown | 24.9 | N.D. /0.12 | 1 /8 | Unknown | ||
| M19 | PDP-3, -4, -54-c | 25.9–26.0 | 559/529/543 | 27.45 | N.D. /0.46 | 3 /8 | Impurities-coelute |
Radiomatic peak integrations of peaks representing <2.5% of peaks in a chromatogram were variable; therefore, minimum and maximum range data are valid as estimates only and represent the lowest and highest observed percentage of dose in individual patients. Ranges are more reliable for metabolites representing >2.5% of dose (CPT-11, SN-38, APC and SN-38 glucuronide).