The single-dose disposition kinetics of orbifloxacin were determined in clinically normal lactating goats (n = 6) after intravenous, subcutaneous, and intramuscular administration of 2.5 mg of orbifloxacin/kg of body weight. Orbifloxacin concentrations were determined by HPLC with fluorescence detection. The concentration-time data were analyzed by compartmental and noncompartmental kinetic methods. Steady-state volume of distribution and clearance of orbifloxacin after intravenous administration were 1.13 +/- 0.08 L/kg and 0.40 +/- 0.11 L/h x kg, respectively. Following subcutaneous and intramuscular administration, orbifloxacin achieved maximum plasma concentrations of 1.85 +/- 0.20 and 1.66 +/- 0.14 mg/L at 1.25 +/- 0.22 and 0.87 +/- 0.38 h, respectively. The absolute bioavailabilities after subcutaneous and intramuscular routes were 108.96 +/- 17.61% and 105.01 +/- 15.61%, respectively. Orbifloxacin penetration from the blood into the milk was rapid and showed high levels of concentrations in milk secretion. From this data, orbifloxacin could have success against susceptible mastitis pathogens in goats.

AIMS: To determine the pharmacokinetics, and anaesthetic and sedative effects of alfaxalone after I/V and I/M administration to cats. METHODS: Six European shorthair cats, three males and three females, with a mean weight of 4.21 (SD 0.53) kg and aged 3.8 (SD 0.9) years were enrolled in this crossover, two–treatment, two-period study. Alfaxalone at a dose of 5 mg/kg was administered either I/V or I/M. Blood samples were collected between 2–480 minutes after drug administration and analysed for concentrations of alfaxalone by HPLC. The plasma concentration-time curves were analysed by non-compartmental analysis. Sedation scores were evaluated between 5–120 minutes after drug administration using a numerical rating scale (from 0–18). Intervals from drug administration to sit, sternal and lateral recumbency during the induction phase, and to head-lift, sternal recumbency and standing position during recovery were recorded. RESULTS: The mean half-life and mean residence time of alfaxalone were longer after I/M (1.28 (SD 0.21) and 2.09 (SD 0.36) hours, respectively) than after I/V (0.49 (SD 0.07) and 0.66 (SD 0.16) hours, respectively) administration (p<0.05). Bioavailability after I/M injection of alfaxalone was 94.7 (SD 19.8)%. The mean intervals to sternal and lateral recumbency were longer in the I/M (3.73 (SD 1.99) and 6.12 (SD 0.90) minutes, respectively) compared to I/V (0 minutes for all animals) treated cats (p15) were recorded from 5–15 minutes after I/V administration and deep sedation (scores 11–15) at 20 and 30 minutes. Deep sedation was observed from 10–45 minutes after I/M administration. One cat from each group showed hyperkinesia during recovery, and the remainder had an uneventful recovery. CONCLUSIONS AND CLINICAL RELEVANCE: Alfaxalone administered I/V in cats provides rapid and smooth induction of anaesthesia. After I/M administration, a longer exposure to the drug and an extended half life were obtained compared to I/V administration. Therefore I/M administration of alfaxalone could be a reliable, suitable and easy route in cats, taking into account that alfaxalone has a slower onset of sedation than when given I/V and achieves deep sedation rather than general anaesthesia.

The single-dose disposition kinetics of the antibiotic danofloxacin were determined in clinically normal loggerhead turtles (n = 6) after intravenous (IV), subcutaneous (SC) and intramuscular (IM) administration of 6 mg kg(-1) bodyweight. Danofloxacin concentrations were determined by high performance liquid chromatography with fluorescence detection. The concentration-time data were analyzed by non-compartmental kinetic methods. Steady-state volume of distribution, and total body clearance of danofloxacin after IV administration were estimated to be 1.02 +/- 0.17 1 kg(-1) and 0.11 +/- 0.01 1 h(-1) kg(-1), respectively. Following IM and SC administration, danofloxacin achieved maximum plasma concentrations of 10.25 +/- 4.59 and 10.35 +/- 4.45 mg l(-1) at 1.20 +/- 0.52 and 1.46 +/- 0.48 h, respectively. The absolute bioavailabilities after SC and IM routes were 98.72 +/- 11.73 and 104.81 +/- 14.97%, respectively. Danofloxacin shows a favourable pharmacokinetic profile in loggerhead turtles reflected by parameters such as a long half-life and a high bioavailability following a single dose of 6 mg kg(-1) by IM and SC routes; thus, it is likely that this treatment will be effective in loggerhead turtles with bacterial infections.