title: Pharmacokinetics and metabolism of [14C]rosaramicin in dogs.
abstract: The pharmacokinetics and metabolism of [14C]rosaramicin were studied in dogs after intravenous (i.v.; 10 mg/kg [bodyweight]) and oral (25 mg/kg) administration. After i.v. administration, rosaramicin levels in plasma declined rapidly, with half-lives of 0.22 h for the distribution phase and 0.97 h for the elimination phase. The apparent volume of distribution was 3.43 liters/kg, and the total body clearance was 106 mg/min . kg, indicating extensive distribution in tissue or metabolism or both. The absorption of oral solution was 58%, and the absolute bioavailability of rosaramicin was 35%. The plasma area under the curve of unchanged rosaramicin was only 5% that of total radioactivity after oral administration and 8% after i.v. administration, indicating extensive metabolism of the drug. The total radioactivity excreted in urine accounted for only 24% of the i.v. dose and 17% of the oral dose. Fecal radioactivity accounted for 71% of the i.v. dose and 68% of the oral dose. Several metabolites were observed in the plasma and urine. The amount of unchanged rosaramicin in urine (1 to 2% of the dose) was quite small after drug administration by either route.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002851:Chromatography, High Pressure Liquid; D004285:Dogs; D005243:Feces / Q000032:analysis; D007275:Injections, Intravenous; D007408:Intestinal Absorption; D007700:Kinetics; D007933:Leucomycins / Q000008:administration & dosage / Q000378:metabolism*; D013997:Time Factors
chemical_list: D007933:Leucomycins