TILMICOSIN RESIDUES AND DETERMINATION OF THE WITHDRAWAL PERIOD OF TILMOVET SOLUTIO PRO INJECTIONIBUS 30% AFTER SINGLE SUBCUTANEOUS INJECTIONTO CALVES

摘要

Aim: Determination of tissue residues and withdrawal period in calves after single subcutaneous infection of Tilmovet solutio pro imjectionibus 30% (Biovet LTD Peshtera), containing tilmicosin phosphate. Four clinically healthy calves of both genders(Brown Bulgarian breed) weighing 78 to 94 kg were used. All calves were treated once subcutaneously with Tilmovet solutio pro imjectionibus 30% at 1 mL/30 kg (= 10 mg/kg tilmicosin phosphate). The calves were euthanized 28 days after the injection of thedrug. The residues in marker organs and tissues were assayed by means of a validated HPLC method. There were no deviations from the health condition of calves. By the 28th day after the injection, residues in liver, kidneys, untreated -muscles and muscles at the site of injection were 380.8±48.7 ug/kg, 116.5±27.3 ug/kg, 23.8±3.5 ug/kg, 26.3±6.1 jag/kg, and <32 ug/kg, respectively. Both individual values and upper limits of 95% confidence intervals were lower than MRL allowances. The mean residue levels in usually consumed animal products - meat, liver, kidney and fat (52.6±6.47 ug) were lower than the acceptable daily intake (ADI) for tilmicosin. In order to guarantee a maximum safety from the consumption of products from large ruminants treatedonce subcutaneously with Tilmovet solutio pro imjectionibus 30% at a dose of 10 mg/kg tilmicosin, a 28-day withdrawal period is recommended.