title: Pharmacokinetics and bioavailability of orbifloxacin oral suspension in New Zealand White rabbits (Oryctolagus cuniculus).
abstract: OBJECTIVE To evaluate the pharmacokinetics and bioavailability of 2 doses of orbifloxacin in rabbits. ANIMALS 6 healthy purpose-bred adult female New Zealand White rabbits (Oryctolagus cuniculus). PROCEDURES Each of 3 rabbits received orbifloxacin at either 10 or 20 mg/kg, PO. Then, after a 1-week washout period, they received the same dose IV. Blood samples were collected from each rabbit at 0, 0.25, 0.5, 1, 2, 4, 6, 12, and 24 hours after drug administration. Plasma orbifloxacin concentration was measured with liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were determined by noncompartmental analysis for data obtained following PO administration and noncompartmental and compartmental analyses for data obtained following IV administration. RESULTS Following oral administration, the mean ± SD peak plasma orbifloxacin concentration was 1.66 ± 0.51 μg/mL for rabbits administered the 10 mg/kg dose and 3.00 ± 0.97 μg/mL for rabbits administered the 20 mg/kg dose and was attained at 2 hours after drug administration. The mean ± SD half-life of orbifloxacin in plasma was 7.3 ± 1.1 hours for rabbits administered the 10 mg/kg dose and 8.6 ± 0.55 hours for rabbits administered the 20 mg/kg dose. Mean bioavailability was 52.5% for rabbits administered the 10 mg/kg dose and 46.5% for rabbits administered the 20 mg/kg dose. CONCLUSIONS AND CLINICAL RELEVANCE Results provided pharmacokinetic properties for 2 doses (10 mg/kg and 20 mg/kg) of orbifloxacin oral suspension in rabbits. Further studies are necessary to determine the protein-binding activity of orbifloxacin in rabbits before dosages for the treatment of common pathogens in this species are recommended.
authors.forename: Megan K
authors.initials: MK
authors.lastname: Watson
authors.forename: Luke A
authors.initials: LA
authors.lastname: Wittenburg
authors.forename: Christine T
authors.initials: CT
authors.lastname: Bui
authors.forename: Kira A
authors.initials: KA
authors.lastname: Jarosz
authors.forename: Daniel L
authors.initials: DL
authors.lastname: Gustafson
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Johnston
mesh_terms: D000284:Administration, Oral; D000818:Animals; D019540:Area Under Curve; D001682:Biological Availability; D002853:Chromatography, Liquid; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006207:Half-Life; D007262:Infusions, Intravenous; D013058:Mass Spectrometry; D011817:Rabbits; D011897:Random Allocation
chemical_list: D002939:Ciprofloxacin; C095163:orbifloxacin