Murine pharmacokinetics and metabolism of penclomedine [3,5-dichloro-2,4-dimethoxy-6-(trichloromethyl)pyridine, NSC 338720].
Penclomedine, a highly substituted pyridine derivative, has been selected by the National Cancer Institute for evaluation as a potential anticancer agent based on antitumor activity observed in murine tumor models following i.v., p.o., and i.p. administration. We have developed a reverse-phase high performance liquid chromatography assay for PEN, and subsequently investigated murine pharmacokinetics and metabolism. Following rapid i.v. injection of PEN (300 mg/m2) to mice, plasma elimination was best described by a 2-compartment open model with an elimination phase half-life, total body clearance, and steady-state distribution volume of 69 min, 114 ml/min/m2, and 4800 ml/m2, respectively. While PEN displayed good p.o. absorption, bioavailability of PEN after p.o. administration was approximately 2% of that observed following i.v. administration. Metabolism contributed substantially to drug clearance, and total metabolites were slowly eliminated from plasma. After i.v. and p.o. administration of radiolabeled PEN, less than 0.2% of the parent drug was excreted in the 48-h urine, and 25-30% of the total radioactivity was recovered in urine. NADPH-dependent oxidative and reductive metabolism was observed when penclomedine was incubated with mouse microsomal preparations. Microsomal reductive metabolism of PEN led to formation of a metabolite tentatively identified as a molecule formed by dimerization of the radical species produced by cleavage of chlorine from the trichloromethyl moiety of penclomedine.
Reid
J M
JM
Mayo Clinic and Foundation, Department of Oncology, Rochester, Minnesota 55905.
Mathiesen
D A
DA
Benson
L M
LM
Kuffel
M J
MJ
Ames
M M
MM
D000818:Animals; D000970:Antineoplastic Agents / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D006801:Humans; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009374:Neoplasms, Experimental / Q000188:drug therapy / Q000473:pathology; D010847:Picolines / Q000378:metabolism / Q000493:pharmacokinetics* / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000970:Antineoplastic Agents; D010847:Picolines; C058388:penclomedine