title: Stability of florfenicol in drinking water.
abstract: Florfenicol, a broad-spectrum antibiotic, is being developed for veterinary application as an oral concentrate intended for dilution with drinking water. When a drug product is dosed via drinking water in a farm setting, a number of variables, including pH, chlorine content, hardness of the water used for dilution, and container material, may affect its stability, leading to a decrease in drug potency. The stability of florfenicol after dilution of Florfenicol Drinking Water Concentrate Oral Solution, 23 mg/mL, with drinking water was studied. A stability-indicating, validated liquid chromatographic method was used to evaluate florfenicol stability at 25 degrees C at 5, 10, and 24 h after dilution. The results indicate that florfenicol is stable under a range of simulated field conditions, including various pipe materials and conditions of hard or soft and chlorinated or nonchlorinated water at low or high pH. Significant degradation (> 10%) was observed only for isolated combinations in galvanized pipes. Analysis indicated that the florfenicol concentration in 8 of the 12 water samples stored in galvanized pipes remained above 90% of the initial concentration (100 mg/L) for 24 h after dilution.
authors.affiliation: Schering-Plough Research Institute, Analytical Development, 2000 Galloping Hill Rd, Kenilworth, NJ 07033, USA. john.hayes@spcorp.com
authors.forename: John M
authors.initials: JM
authors.lastname: Hayes
authors.forename: Jonathan
authors.initials: J
authors.lastname: Eichman
authors.forename: Terry
authors.initials: T
authors.lastname: Katz
authors.forename: Rosalia
authors.initials: R
authors.lastname: Gilewicz
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000737:chemistry*; D002713:Chlorine / Q000032:analysis; D002853:Chromatography, Liquid; D004326:Drinking; D004355:Drug Stability; D006863:Hydrogen-Ion Concentration; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions; D013839:Thiamphenicol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D012996:Solutions; D014867:Water; D002713:Chlorine; C035534:florfenicol; D013839:Thiamphenicol