COMPARATIVE STUDIES BETWEEN RESIDUES OF NORFLOXACIN AND CIPROFLOXACIN IN BROILER CHICKENS WITH SPECIAL REFERENCE TO THEIR WITHDRAWAL TIME

A single oral dose of norfloxacin (10mg/kg b.w.) and ciprofloxacin (5mg/kg b.w.) was administered for 30 broiler chickens for studying the comparative pharmacokinetic and pharmacodynamic data as well as residues in poultry tissues. The concentrations of two drugs in serum samples and its residues in tissues were assayed using HPLC with fluorescence detection. Results showed rapid absorption for two drugs reaching to maximum serum concentrations (1.39 and 4.46mg/ml) after 2 and 0.67h. The plasma levels were maintained above MIC90 recorded for major poultry pathogenic Gram-negative and Gram-positive bacteria for 10 and 24h with norfloxacin and ciprofloxacin respectively. The study illustrated that the administered dose for two drugs were adequate for 24h for controlling avian diseases caused by bacteria sensitive to these drugs. Seven and five days are enough as withdrawal periods for norfloxacin and ciprofloxacin respectively to decrease its concentr-ations blow the MRL authorized for these drugs