title: [Absorption, distribution, metabolism and excretion of bacmecillinam. I. Absorption, distribution, metabolism and excretion of 14C-bacmecillinam following oral administration to rats].
abstract: The pharmacokinetics of bacmecillinam (KW-1100), a new semisynthetic penicillin, was studied. Plasma levels, tissue distribution, metabolites and urinary and biliary excretion of mecillinam after oral administration of KW-1100 were studied in rats given a dose of 20 mg/kg (as mecillinam). The absorption of 14C-KW-1100 was so rapid that the level in blood was found to reach the peak 30 minutes after administration. 14C-KW-1100 was distributed widely into various tissues and relatively high distribution was noted in liver, kidney, adrenal gland and spleen. No accumulation of 14C-KW-1100 in any tissue was found. It was excreted rapidly from each tissue. Within 24 hours after administration of KW-1100, approximately 86% of the given dose was excreted. And within 72 hours, approximately 97% of the dose was excreted. Excretions in urine and feces within 72 hours after KW-1100 administration were 39.5 and 57.4% of the given dose, respectively. Biliary excretion was 2.0% of the given dose within 24 hours after administration of KW-1100. The major metabolite in the plasma at peak time (30 minutes) was mecillinam (50.5%). The major metabolite in the urine (0 approximately 8 hours) was mecillinam (52.2%), too. The minor metabolites were 5,5-dimethyl-2-(1'-formamidomethyl)-thiazolidine-1',4-dicarboxylat e(M-1), 6-beta-[(hexahydro-1H-azepin-1-yl)-methyleneamino]-penicilloic acid (M-6) and M-4.
mesh_terms: D000284:Administration, Oral; D000560:Amdinocillin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D000818:Animals; D001646:Bile / Q000378:metabolism; D007408:Intestinal Absorption; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014018:Tissue Distribution
chemical_list: C021145:bacmecillinam; D000560:Amdinocillin