Influence of dietary citric acid and calcium on the bioavailability of orally administered chlortetracycline in piglets.
In a study involving 18 piglets divided into three groups (A, B and C), the effects of dietary calcium and citric acid, and feeding technique on chlortetracycline bioavailability were examined. Groups of 6 animals received a basal diet with either 0.7% (group A) or 1.4% calcium (groups B and C). Citric acid was not included in diets of the first experimental period. In the second period, either 1.5% (groups A and B) or 3.0% (group C) citric acid was added to the diet. In both experimental periods, chlortetracycline was administered once intravenously (7.5 mg/kg b.w.) and once orally (30 mg/kg b.w.). After each administration, blood samples were taken at regular intervals in order to determine chlortetracycline serum concentrations by a microbiological method. Following oral chlortetracycline intake, low dietary calcium or citric acid addition to the diet produced increased chlortetracycline serum concentrations. Chlortetracycline bioavailability was 12.6% at 0.7% dietary calcium, and 9.5% at 1.4% dietary calcium. Enteral chlortetracycline absorption was improved 65% with 1.5% or 3.0% dietary citric acid supplementation. An 8-hour delay of feed intake following oral chlortetracycline intake did not significantly influence chlortetracycline bioavailability.
Wanner
M
M
Division of Animal Nutrition, University of Zürich, Switzerland.
Walker
W
W
Sutter
H M
HM
Riond
J L
JL
Broz
J
J
D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D002136:Calcium, Dietary / Q000494:pharmacology*; D002751:Chlortetracycline / Q000008:administration & dosage / Q000493:pharmacokinetics*; D002951:Citrates / Q000008:administration & dosage / Q000494:pharmacology*; D019343:Citric Acid; D004347:Drug Interactions; D008297:Male; D013552:Swine / Q000378:metabolism*
D002136:Calcium, Dietary; D002951:Citrates; D019343:Citric Acid; D002751:Chlortetracycline