title: Pharmacokinetic and milk penetration of a difloxacin long-acting poloxamer gel formulation with carboxy-methylcellulose in lactating goats.
abstract: The single-dose disposition kinetics of difloxacin were determined in clinically normal lactating goats (n=6) after subcutaneous administration of a long-acting poloxamer 407 gel formulation with carboxy-methylcellulose (P407-CMC). Difloxacin concentrations were determined by high performance liquid chromatography with fluorescence detection. The concentration-time data were analysed by non-compartmental kinetic methods. Plasma and milk elimination half-lives after P407-CMC dosing were 35.19 h and 33.93 h, respectively. With this formulation, difloxacin achieved maximum plasma concentrations of 2.67±0.34 mg/L at 2.92±1.20 h and maximum milk concentrations of 2.31±0.35 mg/L at 4.00±0.00 h. The area under the curve (AUC) ratio AUC(milk)/AUC(plasma) was 0.89 after P407-CMC administration. It was concluded that a 15 mg/kg dose of difloxacin within P407-CMC would be effective against mastitis pathogens with a minimum inhibitory concentration (MIC)≤0.12 mg/L.
authors.affiliation: Department of Pharmacology, Faculty of Veterinary Medicine, University of Murcia, Campus de Espinardo, 30.071 Murcia, Spain.
authors.forename: Elisa
authors.initials: E
authors.lastname: Escudero
authors.forename: Pedro
authors.initials: P
authors.lastname: Marín
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Cárceles
authors.forename: María J
authors.initials: MJ
authors.lastname: Ramírez
authors.forename: Emilio
authors.initials: E
authors.lastname: Fernández-Varón
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D005260:Female; D005782:Gels; D015511:Goat Diseases / Q000188:drug therapy; D006041:Goats / Q000378:metabolism*; D006207:Half-Life; D007279:Injections, Subcutaneous / Q000662:veterinary; D007774:Lactation / Q000378:metabolism*; D008413:Mastitis / Q000188:drug therapy / Q000662:veterinary; D008892:Milk / Q000737:chemistry*
chemical_list: D000890:Anti-Infective Agents; D005782:Gels; D002939:Ciprofloxacin; C047225:difloxacin