Bioavailability, pharmacokinetics, and plasma concentration of tetracycline hydrochloride fed to swine.
A 2 X 2 crossover design trial was conducted in gilts to determine the bioavailability and pharmacokinetics of tetracycline hydrochloride. The bioavailability of tetracycline hydrochloride administered orally to fasted gilts was approximately 23%. After intravascular administration, the disposition kinetics of tetracycline in plasma were best described by a triexponential equation. The drug had a rapid distribution phase followed by a relatively slow elimination phase, with half-life of 16 hours. Its large volume of distribution (4.5 +/- 1.06 L/kg) suggested that tetracycline is distributed widely in swine tissues. Total body clearance was 0.185 +/- 0.24 L/kg/h. Other pharmacokinetic variables were estimated. In a second trial, 3 gilts were fed a ration containing 0.55 g of tetracycline hydrochloride/kg of feed. Resulting plasma concentration of tetracycline was determined at selected times during 96 hours after exposure to the medicated feed. Plasma drug concentration peaked (0.6 micrograms/ml) at 72 hours after access to the medicated feed.
Kniffen
T S
TS
Department of Veterinary Clinical Medicine, Veterinary Biosciences, College of Veterinary Medicine, University of Illinois, Urbana 61801.
Bane
D P
DP
Hall
W F
WF
Koritz
G D
GD
Bevill
R F
RF
D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D001682:Biological Availability; D005260:Female; D007269:Injections, Intra-Arterial; D010118:Oxytetracycline / Q000493:pharmacokinetics; D013552:Swine / Q000378:metabolism*; D013752:Tetracycline / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D013997:Time Factors
D013752:Tetracycline; D010118:Oxytetracycline