Abstract

PHARMACOKINETICS, BIOAVILABILITY AND TISSUE RESIDUES OF APRAMYCIN IN NORMAL CHICKENS AND ESCHERICHIA COLI INFECTED BROILER CHICKENS

EL. Sayed*, M.G.A. EL-Komy, A.A.A. and Soliman, A. Asmaa

ABSTRACT

The pharmacokinetics (after single intravenous, and oral administration) and tissue residues after repeated oral (daily for five days) administration of apramycin were investigated in normal and experimentally Escherichia coli infected chickens. Apramycin was administered at a dose level of 25 mg/kg b. wt. (for oral administration) and at 10 mg/kg b. wt. for intravenous injection. Fourty six clinically normal Hubbard chicken of four weeks of age weighting about 1500 to 2000 grams were used in the current study. The maximum plasma concentrations of apramycin were achieved 0.705 μg/ml at 0.5 hour after oral administration and 35.09 μg/ml at 0.083 hours after intravenous injection. The systemic bioavailability was 1.31% after oral administration indicating poor absorption of apramycin. After intravenous injection, the pharmacokinetics of apramycin was best described by a three-compartment open model with at t1/2α of 0.113 hour, t l/2β of 0.999 hour, t0.5(ɤ) of 4.56 hour, Vdss of 1460.19 ml/kg. The plasma protein binding of apramycin was 7.13 ± 0.444 %. oral administration of 25 mg apramycin per kilogram body weight three times daily for five consecutive days in normal and Escherichia coli infected chickens revealed a lower significant serum apramycin concentration in Escherichia coli infected chickens compared with normal chickens. The highest tissue concentrations of apramycin were present in the kidneys and liver.

Keywords: Apramycin; Pharmacokinetics; Bioavailability; Residues; Broiler chickens.