Pharmacokinetics of valnemulin after intravenous, intramuscular, and oral administration in layer chickens.

Abstract

The pharmacokinetic characteristics of valnemulin in layer chickens were studied after single intravenous, intramuscular, and oral administration at a dose of 15mg/kg body weight. Plasma samples at certain time points were collected and the drug concentrations in them by ultra high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS). The concentration-time data for each individual were plotted by noncompartmental analysis for the whole three routes. Following intravenous administration, the plasma concentration showed tiny fluctuation. The elimination half-life (T1/2λz), total body clearance (Cl), and area under the plasma concentration-time curve (AUC) were 1.85±0.43h, 2.2±0.9L/h, and 7.52±2.46 μg·h/mL, respectively. Following intramuscular administration, the peak concentration (Cmax , 1.40±0.43μg/mL) was achieved at the time of 0.34h. A multiple-peak phenomenon existed after oral administration, and the first peak and secondary peak were at 10min and during 2-4h, respectively, while the tertiary peak appeared during 5-15h. The bioavailability (F %) for intramuscular and oral administration was 68.60% and 52.64%, respectively. In present study, the detailed pharmacokinetic profiles showed that this drug is widely distributed and rapidly eliminated, however has a low bioavailability, indicating that valnemulin is likely to be a favorable choice in the clinical practice.