The effect of zinc on pharmacokinetics of sulphadiazine at broilers

The aim of this study is to determine the pharmacokinetics of sulphadiazine that administered intravenously (iv) and via gizzard at a single dose of 100 mg/kg, and to find out whether there is an interaction between sulphadiazine and zinc when applied combined in feed. Totally 40, 31-day old broilers were used. Chicks were fed without medication for 25 days. At the end of this period the chickens were divided into 4 groups; control feed to Group 1 and 2, 200 ppm zinc added feed to Group 3 and 4 were given for 5 days. Sulphadiazine was administered at a single dose of 100 mg/kg intravenously to the Group 1. After the injection of the drug, 1 ml blood was taken into heparinized tubes at 5., 15. and 30. minutes and 1., 2., 4., 6., 8., 12., 18. and 24. hours. Group 2 and 3 were given suspension of sulphadiazine into gizzard. Group 4 was administered 100 mg/kg sulphadiazine in drinking water. In all 3 groups, the same protocol as described in IV application (except for 5th minute) was used, blood was taken into heparinized tubes from all 3 groups. The drug density was determined by spectrophotometric method from the plasma separated by centrifuge. Plasma drug concentration-time curve showed two-compartment open model. There were significant differences in terms of bioavailability (F) of the broiler chickens with 200 ppm zinc added feed and feed without zinc ( 91,97 % in Group 2; 64,14 % in Group 3; 60,81 % in Group 4)