Egg residue and depletion in Rhode Island Red hens (Gallus gallus domesticus) following multiple oral doses of trimethoprim-sulfamethoxazole

Ionophore coccidiostats – disposition kinetics in laying hens and residues transfer to eggs

“…The model was calibrated and validated for 7 chemical substances that are relevant to food and feed safety, and predictions of plasma, tissue, and egg concentrations were made, which are in excellent agreement with published data ( Lautz et al, 2020 ). Recently, Enomoto et al (2021) have reported residues deposition and depletion in eggs following multiple oral administrations of trimethoprim-sulfamethoxazole in laying hens taking into account differences in the rate of excretion in egg white and yolk. These 2 references provided insight into the physiological prediction of drug residue in eggs.…”

Pharmacokinetics and Safety of Sulfamethoxazole-Trimethoprim After Oral Administration of Single and Multiple Doses to Rhode Island Red Chickens (Gallus gallus domesticus)

“…The limited absorption of TMP (pKa ¼ 7.12, logP [logarithm of the partition coefficient] ¼ 0.9) from the gastrointestinal membrane, combined with a low lipophilicity and permeability of intestinal membranes for this drug, has been hypothesized as a cause for reduced gastrointestinal absorption and short elimination half-life in chickens. [25][26][27][28] Goren et al 25 reported only small differences in plasma concentrations in poultry administered TMP at doses of 42, 60, and 120 mg/kg via drinking water; therefore, dramatic increases in oral doses of TMP may also not yield significant increased plasma concentrations in this species.…”

Residue, distribution and depletion of fluralaner in egg following a single intravenous and transdermal administration in healthy shaver hens: fluralaner residue in egg

“…Drug concentration in the whole egg was calculated based on weights of yolk and albumen with fluralaner concentration in yolk and albumen from following the equation ( Enomoto et al, 2021 ): …”

“…Drug distribution (%) into yolk and albumen was calculated for each egg sample following the equations described below ( Enomoto et al, 2021 ). …”

“…The differences in development of yolk and albumen at the development stage of egg production can also impact the drug distribution in egg yolk and albumen. Development of the yolk including accumulation of lipoprotein is a long process and fluralaner is a lipophilic compound, therefore, it is expected that yolk can be an important site for fluralaner residues in hens ( Enomoto et al, 2021 ). Since fluralaner is being considered for use to treat mites and bed bugs in hens, there is a need for data driven withdrawal interval ( WDI ) recommendations to avoid the violative residue following the fluralaner administered to laying hens.…”