Pharmacokinetics and relative bioavailability of tiamulin in broiler chicken as influenced by different routes of administration

Abstract

The bioavailability and pharmacokinetic disposition of tiamulin in broiler chicken were investigated after administration through the crop, drinking water, and feed at 40 mg/kg body weight. Residues of tiamulin in tissues of broiler chicken were also assessed. Plasma and tissue concentrations of tiamulin were analyzed by reverse‐phase high‐performance liquid chromatography (HPLC) method. Plasma concentration–time data were described by the non‐compartmental model for all three routes, and pharmacokinetic parameters were calculated. There were no significant differences (p > 0.05) in pharmacokinetic parameters and mean plasma concentrations of tiamulin between three routes tested (crop, water, and feed), indicating equal efficacy. Tiamulin residues in edible tissues (muscles, skin, and fat) were lower than the advocated maximum residue limit (MRL of 0.1 µg/g and that of liver was 1 µg/g) on the 3rd day. No traces were found on the 5th day after drug administration. This indicated that the withdrawal period (less than 5 days) is very short, which makes it safer. This study shows that tiamulin can be used with equal efficacy through all routes of administration in broiler chicken (crop, water, and feed).

Tissue Residues and Pharmacokinetic/Pharmacodynamic Modeling of Tiamulin Against Mycoplasma anatis in Ducks

“…The findings of this study revealed that tiamulin, when administered orally to ducks, was rapidly absorbed with C max values [0.77 and 2.32 µg/mL attained at 2 h (T max ) for 30 and 60 mg/kg, respectively] and these values were similar to those reported for dogs, goats, and ewes, which were injected with tiamulin intramuscularly (i.m.) at 10 mg/kg (0.60, 0.56, and 0.64 µg/mL, respectively) (14, 37), pig administered tiamulin orally at 10 mg/kg (0.69 µg/mL) (13), chickens received tiamulin orally at 40 mg/kg (0.73 µg/mL reached at 1.5 h) (16), and for chickens injected with tiamulin i.m. at 5 mg/kg (2.05 µg/mL) and 40 mg/kg (8.8 µg/mL) (15).…”

“…Moreover, the present study showed a second peak at 8 h post-tiamulin administration with the two different doses. This is likely due to the enterohepatic recycling of tiamulin during biliary elimination (15,16). In addition, following oral administration of tiamulin at 30 mg/kg, the AUC extrapolated to infinity was 5.85 µg * h/mL.…”

“…In the 2nd experiment, 30 ducks were administered tiamulin orally via gavage at 40 mg/kg daily for 3 successive days (6,16). After the 3rd day of treatment, 6 ducks each were slaughtered on 1st, 3rd, 5th, 7th, and 9th day after the tiamulin dosing.…”

“…The pharmacokinetic profile of tiamulin was investigated utilizing the non-compartmental approach [WinNonlin 8.3 software (Certara, USA)] as reported (15,16). The values of the highest plasma concentration (C max ) and the time required to attain C max (T max ) were recorded from the plasma concentration-time plot.…”

“…The high lipid solubility of tiamulin accounts for its extensive distribution throughout the tissues of birds and mammals (10,11). The pharmacokinetics of tiamulin have been studied in pigs (11,12), piglets (13), goats, ewe, cows, calves (14), chickens and turkeys (10,12,15,16). However, there are no data available on the pharmacokinetics of tiamulin in ducks.…”