title: Chlortetracycline in swine--bioavailability and pharmacokinetics in fasted and fed pigs.
abstract: Chlortetracycline hydrochloride was administered intra-arterially (11 mg/kg) and as an oral drench (33 mg/kg) to ten 21.0-31.5-kg pigs. Five of the pigs were fasted 18 h prior to dosing and five of the pigs were fed ad libitum prior to dosing. The mean volume of distribution determined by area-under-the-curve calculations for the fasted pigs (0.967 +/- 0.210 l/kg) was significantly less (P less than 0.05) than the mean volume of distribution for the fed pigs (1.39 +/- 0.31 l/kg). Mean total body clearance of the drug was also significantly less (P less than 0.05) in the fasted pigs (0.165 +/- 0.055 l/kg/h) as compared to the fed pigs (0.307 +/- 0.053 l/kg/h). The elimination constants (beta) were not found to be statistically different (P less than 0.05): 0.1811 +/- 0.0057 for the fasted pigs; 0.2260 +/- 0.0461 for the fed pigs. The bioavailability for both groups was similar; 19.12 +/- 8.3% for the fasted pigs and 17.88 +/- 5.3% for the fed pigs. In a second experiment three groups of six pigs which weighed 34.5-44.1 kg were fed a corn-soy diet ad libitum. The rations were fortified with chlortetracycline at 100, 400 or 1000 mg chlortetracycline hydrochloride/kg feed. Chlortetracycline concentrations were determined in plasma samples collected over a 6-day period. Plasma chlortetracycline concentrations reach a plateau within 24 h after initial access to the trial diets and were highly correlated with the dose of the drug consumed (r2 = 0.97).
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Illinois, Urbana.
authors.forename: C R
authors.initials: CR
authors.lastname: Kilroy
authors.forename: W F
authors.initials: WF
authors.lastname: Hall
authors.forename: D P
authors.initials: DP
authors.lastname: Bane
authors.forename: R F
authors.initials: RF
authors.lastname: Bevill
authors.forename: G D
authors.initials: GD
authors.lastname: Koritz
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002751:Chlortetracycline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D005215:Fasting / Q000378:metabolism*; D005260:Female; D007269:Injections, Intra-Arterial / Q000662:veterinary; D008297:Male; D008657:Metabolic Clearance Rate; D010118:Oxytetracycline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics; D013552:Swine / Q000378:metabolism*; D013997:Time Factors
chemical_list: D002751:Chlortetracycline; D010118:Oxytetracycline