PHARMACOKINETICS AND ELIMINATION OF KITAZ AMYCIN IN CHICKENS - ITS RESIDUE IN LAYING HENS

Pharmacokinetics and tissular distribution of orally applicated kitaza mycin were studied in three experiments in broiler chickens. The resid ue content of eggs was studied in laying hens. Details of the experime ntal data are shown in Table 1. The macrolid antibiotic was measured w ith a detection limit of 20-100 mug/kg by a microbiological method, us ing the BGA ATCC 6633 test strain of B. subtilis. It was found that th e resorbtion of 80 mg/kg of bodymass kitazamycin, given orally to 10 c hickens, was -prompt (t5oa = 0,89 hour), the maximal blood level was 1 .451 +/- 0.16 mg/l in 2.19 hours following the administration. The eli mination of this antibiotic was also prompt, its half-period was 1.1 h our (Tables 2 and 3). During the five days treatment of 10 chickens (4 00 mg/l via drinking water = 130 mg/kg of bodymass/day), the highest d rug-concentration was measured in the liver 6 hours after treatments a nd only 40% of that could be detected in the muscle and kidneys. Kitaz amycin was present only in traces in the adipose tissues. After 24 hou rs, the level of drug residue showed a very fast diminution in all inv estigated tissue samples (muscle was negative, 30 mug/kg was the conce ntration in all the other organs). Microbiologically positive organ sa mples were not found after 4 days (Table 4). During the five days trea tment of 10 laying hens (400 mg/l via the drinking water = 32 mg/kg bo dy-mass/day), the albumen of eggs contained the maximal antibiotic con centration (0.384 +/- 0.23 mg/kg) on the 2nd day after treatments. Inh ibiting matter was found in the yolk in none of the cases. However, ki tazamycin could not be detected in the albumen 4 days after treatments (Tables 5 and 6). According to the results obtained, a 4 days withdra wal period of consumption for meat and 7 days for eggs is sufficient a fter kitazamycin treatments.