An evaluation of the effect of repeated doses of oral activated charcoal on the depletion of enrofloxacin residual levels in chicken breast muscles.

The purpose of this study was to determine whether concurrent oral administration of activated charcoal has an affect on the depletion of the residual concentrations of enrofloxacin (ENRO) in chicken breast muscles. Sixty-four broiler chickens were divided into four groups (n = 16 per group), one given a daily oral dose of enrofloxacin with feed at a dose of 10 mg/kg for 5 consecutive days (control group) and the others given the same dose of enrofloxacin simultaneously with activated charcoal at a dose rate of 0.5, 1, and 2 % of daily feed for 5 days (treatment groups). At the end of treatment, 2 hens were sacrificed at each of the sampling time points (6,12, 18,48, 72,96,120 and 144 h after completion of dosing), breast muscles were collected and analyzed. Supercritical fluid extraction and high-performance liquid chromatography methods were used to determine the enrofloxacin residue levels in chicken breast muscles. The limit of quantification (LOQ) 16.5 microg/kg, was lower than the maximum residue levels (MRL) fixed by the Commission of the European Union. For all the time periods, charcoal treatment did not affect enrofloxacin tissue concentrations except at 12 and 48 h post treatment. To our knowledge, no studies on the depletion of enrofloxacin in the presence and absence of activated charcoal in chicken muscles have been performed. Although our current understanding is incomplete, multiple dose activated charcoals may play a role in the therapy of overdose. To prove this, further investigation is warranted.

Single-dose pharmacokinetics of marbofloxacin in Egyptian buffalo (Bubalus bubalis L.) steers.

The objective of this study was to investigate the pharmacokinetics of marbofloxacin (MAR) following intravenous (iv) and intramuscular (im) administration of a 2.0 mg/kg body weight dosage to five healthy Egyptian buffalo steers. A cross-over design was used with a washout period of 2 weeks. Blood samples were obtained at 0, 5,10,15, and 20 min and at 0.5,0.75,1,2,4,6,8,10,12,24,30 and 48 hours after marbofloxacin administration. The serum marbofloxacin concentrations were quantitated using a modified agar diffusion bioassay method. Marbofloxacin exhibited a relatively high volume of distribution at steady-state (Vdss = 1.77 Lkg), which suggests good tissue penetration, and a total body clearance (Cltot) of 0.18 L/kgxh,which is associated with a long elimination half-life (tl/2beta = 7.52 h). Marbofloxacin was rapidly absorbed at a dosage of 2.0 mg/kg after im administration with an observed maximum serum concentration (Cmax) value of 2.004 microg/mL obtained at a time to peak concentration (tmax) of 0.5 h, and an absolute bioavailability (F %) of 86.79 +/- 5.53 %. The protein-binding ranged from 22 to 24.6 % with an average of 23.4 %. In conclusion, single iv and im administered doses of marbofloxacin were well tolerated by Egyptian buffalo steers. A dosage of 2 mg/kg body weight might not be enough to treat infections caused by bacteria with minimum inhibitory concentration (MIC) at or above 0.2 microg/mL, based on the calculated area under the inhibitory concentration (AUIC).