DISPOSITION KINETICS OF AMPICILLIN IN WHITE LEGHORN BIRDS

The pharmacokinetics and tissue disposition of ampicillin after single oral dose (50 mg/kg bw) was studied in 2 groups of White Leghorn (WLH ) birds. The drug attained its peak plasma concentration (1.98 +/- 0.0 7 mug/ml) 4-6 hr post-drug administration. The Cp(ther) ranged from 0. 12 +/- 0.004 to 1.98 +/- 0.07 mug/ml between 30 min to 24 hr. The valu es of pharmacokinetic parameters for t1/2 t1/2 B, Vd(area) and Cl(B) w ere 1.51 +/-0.08 hr, 4.67 +/- 0.12 hr, 19.05 +/- 1.48 liters/kg and 46 .80 +/- 2.61 ml/kg/min respectively. The bioavailability (F) was also high. The mean value of K12, K21, Kel, K12/K21 was 0.08 +/- 0.01 hr-1, 0.29 +/- 0.01 hr-1, 0.23 +/- 0.006 hr-1 and 0.29 +/- 0.03 respectivel y. The level of drug in bile was 26.75 +/- 3.16 and 41.57 +/- 2.67 mug /ml at 4 and 24 hr post-drug administration respectively. Ampicillin r esidual level was determined in different organs and skeletal muscles at 4 and 24 hr post-drug administration. No drug residue was traced in heart and brain at 4 hr. The withdrawal period of consumption of eggs and edible meat collected from ampicillin-treated birds has been advi sed. Dosage regimen based on the kinetics of drug has been suggested f or optimal clinical efficacy.