Pharmacokinetics of diflubenzuron in two types of chickens

Abstract

Pharmacokinetic parameters of [ ¹⁴ C]diflubenzuron, N‐([(4‐chlorophenyl)amino]‐carbonyl)‐2,6‐difluorobenzamide, in White Leghorn (WL) egg‐production chickens and Rhode Island Red/Barred Plymouth Rock (RIR/BPR) meat‐production chickens after single 1‐mg/kg intravenous and single 5‐mg/kg oral doses were investigated to explain a breed‐related egg residue‐level difference (higher in WL chickens) after daily oral administration. Analysis of [ ¹⁴ C]diflubenzuron concentration in blood versus time indicated similar two‐compartment models for each bird type. [ ¹⁴ C]Diflubenzuron elimination half‐lives from the blood of WL and RIR/BPR chickens were 14.7 and 8.4 h, respectively. Absorption of [ ¹⁴ C]diflubenzuron after a single 5‐mg/kg oral dose was both faster and more complete in RIR/BPR chickens. Absorption rate constants were 0.046 h ⁻¹ and 0.192 h ⁻¹ for WL and RIR/BPR hens, respectively. It is concluded that the breed‐related egg residue difference was due to a larger peripheral compartment volume in RIR/BPR hens.