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 4.46g/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 concentrations blow the MRL authorized for these drugs . Comparative Studies Between Residues Of . El-Sheikh, W.M. A. & Elkahky, M.A.A Kafr El-Sheikh Vet.Med.J. Vol. 1 No.1 (2003) 45 INTRODUCTION Fluoroquinolones are important antibacterial agents because of its broad antibacterial activity in veterinary practice (Neer, 1988), that includes most of Gram-negative and part of Gram-positive pathogenic bacteria (Ito, et al, 1980) as well as Mycoplasma spp. and Chlamydia spp. (Proctor et al, 1978 and Shah, 1990). Otherwise, its 2 generation as norfloxacin and ciprofloxacin are used extensively both as oral and injectable formulations for many domestic species due to its good bioavailability and good to excellent tissue distribution, as well as its high activity against aerobic and facultative anaerobic Gram-negative bacilli (Papich, 1998). They exert their bactericidal effect against Gramnegative bacteria in a concentration-dependent manner and show a moderate post-antibiotic effect (Neu et al., 1987). The rational use of norfloxacin and ciprofloxacin for the treatment of common infections in poultry requires detailed information on its pharmacokinetic and pharmacodynamic properties in birds to establish the orally administered dose necessary for maintaining bactericidal drug concentrations in the body. These properties, when combined with microbiological data, provide the right tools needed for targeting its dosage to birds on the basis of pharmacokinetics and the susceptibilities of the bacterial pathogens (Sárközy et al, 2004) . For this, the present study was undertaken to obtain comparative pharmacokinetic data after a single oral administration of norfloxacin and ciprofloxacin; commercial products, in broiler chickens, as well as its residues in different tissues. Comparative Studies Between Residues Of . El-Sheikh, W.M. A. & Elkahky, M.A.A Kafr El-Sheikh Vet.Med.J. Vol. 1 No.1 (2003) 46 MATERIALS AND METHODS A-Drugs:1Norfloxacin: (Mycomas 20% oral liquid, UNIVET Ireland). A synthetic antibacterial 2 generation fluoroquinolone (Ryoji et al., 2006), rapidly bactericidal, active against organisms that may be resistant to other antibacterials such as sulphonamides, ß-lactam, tetracyclines, aminoglycosides and macrolides (Neu and Labthavikul, 1982, and Crumplin et al.,1984) and have great potential for treating common infections such as mycoplasmosis, colibacillosis and pasteurellosis in chickens, turkeys and geese (Norrby and Jonsson, 1983; Prescott and Baggot, 1993 and Keck and Borne, 1995). 2Ciprofloxacin: (Atociprim 20% oral powder, Atcopharma, Egypt) A synthetic antibacterial 2 generation fluoroquinolone (Ryoji et al., 2006), highly effective against both Gram-negative and Gram-positive bacteria including Pseudomonas aeruginosa (Hackbarth, et al., 1986; Neu, 1987; Campoli-Richards, et al.,1988; Demoleas and Davies, 1988; Lefevre, et al., 1988 and Neer, 1988) and treat gonorrhoea, bacterial gastroentritis, skin and soft tissue infections, complicated and uncomplicated urinary tract infections caused by Gram-negative organisms in poultry (Amjad et al, 2005). BAnimals:Sixty healthy Hubbard broiler chickens 35 days of age (1.2-1.5kg body wt), were divided into 2 groups, each thirty marked and housed in separate partition. They acclimatized for one week before the beginning of the experiment, fed on a balanced ration free from any drug or growth promoter and water was available ad libitum. A single oral dose of norfloxacin (10mg/kg b.w for group 1) or ciprofloxacin (5mg/kg b.w for group 2) was given directly into the crop for each bird after food holding for 12h before and 6h after drug administration. Comparative Studies Between Residues Of . El-Sheikh, W.M. A. & Elkahky, M.A.A Kafr El-Sheikh Vet.Med.J. Vol. 1 No.1 (2003) 47 CSampling: One ml of blood was collected from five birds of each group, in heparinized tubes from the contralateral wing vein through a fine plastic intravenous catheter. The samples were taken prior and at 10, 20, 30, 40 min, 1, 2, 3, 4, 6, 8, 12, and 24h after drug administration. Plasma was separated by centrifuge at 3000g for 5min and stored at –20 °C until assayed. Five birds were slaughtered daily from each group, at 5, 6, 7 and 8 days for group1 and at 4, 5, 6 and 7 days for group 2, samples from muscle, liver and kidney were taken and extracted according methods described by (Amjad et al, 2005) for detection of drug residues. Concentration of two drugs in plasma and tissue extracts were determined by HPLC with fluorescence detection with quantitation limits of 0.02g/ml according methods described by Laczay et al, (1998) for norfloxacin and Horie et al, (1994) for ciprofloxacin. The HPLC system consisted of 1525 binary HPLC pump (Waters, Version Number Control Firmware 1.06. CPU Firmware1.3, USA), 717 plus autosampler (Waters, Version Number 3.1, USA), degasserin-Line2 Cham AF (Waters, Version Number 1.04, USA), 2475 multi λ fluorescence detector (Waters, Version Number 1.00, USA) and software Breeze (Waters Breeze HPLC system software). DStandard materials: From Dr. Ehrenstorfer GmbH D-86199 Augsburg Germany. Ciprofloxacin hydrochloride (Reference Standard) Cat. No. C 11668500 MW 367.64 CAS 86393 32-0 Norfloxacin (Reference Standard) Cat. No. C 15648000 MW 319.3. CAS 70458-96-7. EAnalysis: Statistical were carried out according SAS (1987), and the kinetic parameters were calculated according to Baggot (1977). Comparative Studies Between Residues Of . El-Sheikh, W.M. A. & Elkahky, M.A.A Kafr El-Sheikh Vet.Med.J. Vol. 1 No.1 (2003) 48 RESULTES Norfloxacin and ciprofloxacin were rapidly absorbed after oral administration and appear in serum reaching to maximum serum concentrations after 2 and 0.67h respectively (table 1-2 and fig. 1). On the other hand, their levels in poultry tissues (muscle, liver and kidney) were decreased blow permissible MRL (maximum residue limits) at 7 and 5 days respectively (Table 3-4). Table (1): Serum concentrations (g/ml) after a single oral administration of norfloxacin (10mg/kg b.w.) or ciprofloxacin (5mg/kg b.w.) for broiler chickens. Ciprofloxacin (n =5) mean ± SD Norfloxacin (n =5) mean ± SD Time of sampling