Pharmacokinetic study of clazuril (Appertex) in eggs and plasma from laying hens after single or multiple treatments, using a new HPLC method for detection.
1. Anticoccidials are widely used as food additives to prevent and treat coccidiosis. They are licensed for use in a prescribed concentration and during a specific time interval with broilers and pullets, but not for laying hens. 2. This study was set up to develop a new high pressure liquid chromatography (HPLC) method to detect clazuril (CZ: (+/-)-2-chloro-alpha-(4-chlorophenyl)-4-(4,5-dihydro-3,5-dioxo-1,2,4-triazin-2(3H)-yl)-benzeneacetonitrile) in egg yolk and albumen and in plasma; to investigate both the presence of residues of CZ in eggs and its pharmacokinetic behaviour in laying hens. 3. A single oral dose (3 mg/kg BW) and multiple oral doses (3 mg/kg BW for 5 d) were investigated. The analytical method gave very good recovery (64 to 74%) in the three different matrices (yolk, albumen and plasma); precision and accuracy were within 11%. 4. After a single dose no residue was detected in eggs collected for up to 10 d, while following multiple dose treatment, CZ residues were detected until 10 d after the end of treatment. The concentration of the drug was higher in yolk than in albumen with a maximum ratio of 10 : 1. 5. Pharmacokinetics of CZ in laying hens after a single dose showed a detectable concentration of the drug up to 24 h. It reached a steady state after the third administration in multiple dosing. 6. Although further studies are necessary, these results indicate that a single oral dose of CZ could be used as an anticoccidial for laying hens due to the lack of residues in eggs.
Giorgi
M
M
Section of Pharmacology and Toxicology, Department of Veterinary Clinics, Pisa, Italy. mgiorgi@vet.unipi.it
Soldani
G
G
D000097:Acetonitriles / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*; D000418:Albumins / Q000737:chemistry; D000821:Animal Feed; D000818:Animals; D019540:Area Under Curve; D002645:Chickens / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary*; D003049:Coccidiostats / Q000097:blood / Q000737:chemistry / Q000493:pharmacokinetics; D004334:Drug Administration Schedule; D004350:Drug Residues / Q000032:analysis; D004530:Egg Yolk / Q000737:chemistry; D004531:Eggs / Q000032:analysis*; D005260:Female; D006207:Half-Life; D015394:Molecular Structure; D015203:Reproducibility of Results; D014227:Triazines / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics*
D000097:Acetonitriles; D000418:Albumins; D003049:Coccidiostats; D014227:Triazines; C056172:clazuril