Age difference in pharmacokinetics of an amoxycillin trihydrate-15% formulation administered intramuscularly to ruminants

Intramuscular administration of an amoxycillin trihydrate-15% formulation to three groups of animals revealed in preruminant calves (age 3-4 weeks) significant higher plasma peak drug concentrations and shorter biological half-lives than in 5-month-old ruminant calves and dairy cows. Differences in pharmacokinetics were related to age-difference in drug absorption capability at the injection site regarding the formulation.