Pharmaceutical Design of a Formulation of Enrofloxacin-Alginate and its Strategic Dosage to Achieve Mutant Prevention PK/PD Ratios in Broiler Chickens

Introduction The comparative pharmacokinetics (PK) and PK/pharmacodynamics (PD) ratios of a new pharmaceutical design of enrofloxacin-alginate in dried beads (EADBs) and the reference enrofloxacin 10% solution was determined in broiler chickens. Also, the same parameters were determined after administering enrofloxacin with a double dosing scheme (through drinking water and as an in-feed medication of EADBs). 500 Arbor-Acres broiler chickens were randomly divided into five groups (n=100), adjusting in all cases, a dose of 10 mg/kg based on water and feed intake as follows: group EADBsad-lib receiving enrofloxacin through EADBs added to their feed as dressing; group EADBsbolus forcing the beads into the proventriculus using a semi-rigid gavage; group Enroad-lib dosed through their drinking water; group Enrobolus also administered into the proventriculus by gavage; group Enrow & f administering 5 mg/kg as EADBs in their feed, plus 5 mg/kg of enrofloxacin through their drinking water.Methods The PK parameters and the key PK/PD ratios were determined (Cmax/MIC and AUC0-24/MIC). Only group Enrow & f could achieve the PK/PD ratios regarded as mutant-prevention.Results This trial is the first one in which an in-feed medication of enrofloxacin, combined with water dosing, can result in PK/PD parameters superior to those obtained after administering the drug through drinking water at a dose of 10 mg/kg.Conclusion Contrary to expectations, groups Enroad-lib and Enrobolus failed to achieve the desired PK/PD ratios when the breakpoint was established at 0.5 & mu;g/mL but did so when MIC was set at 0.1 & mu;g/mL. In contrast, EADBsbolus and Enrow & f achieved an adequate AUC0-24/MIC ratio for both MIC levels.

Automated summary

This study determined the comparative pharmacokinetics and pharmacodynamics ratios of a new design of enrofloxacin-alginate in dried beads (EADBs) and the reference enrofloxacin 10% solution in broiler chickens. Results showed that a double dosing scheme (EADBs in feed + enrofloxacin in drinking water) achieved better PK/PD ratios compared to single administration through drinking water.