title: Clinical pharmacokinetics of norfloxacin-glycine acetate after intravenous and intramuscular administration to horses.
abstract: The pharmacokinetic properties of norfloxacin-glycine acetate (NFLXGA) were determined in six horses following a single intravenous (i.v.) and intramuscular (i.m.) dose of 4 mgkg(-1) body weight. Following i.v. and i.m. administration, the plasma drug concentrations were best fitted by an open two-compartment model with a rapid distribution phase. After i.v. NFLXGA administration, the distribution (t(1/2alpha)) and elimination half-life (t(1/2beta)) were 0.42 (0.05) and 5.44 (1.36)h. The volume of distribution of NFLXGA at steady state (Vd(ss)) was 2.19 (0.53) Lkg(-1). After NFLXGA i.m. administration, the maximal absorption concentration (C(max)) was 0.44 (0.04) microgml(-1) at 0.86 (0.15)h (T(max)). The mean absorption (t(1/2ka)) and elimination half-life (t(1/2beta)) of NFLXGA were 0.27 (0.07) and 9.47 (2.24)h, respectively. The mean systemic bioavailability (F) following i.m. administration was 55 (12)%. The optimal dosage for each administration route was calculated from the pharmacokinetic data on the basis of the area under the inhibitory plasma concentration-time curve (AUIC) every 24h and was found to be 13.36 and 7.35 mgkg(-1) for i.m. and i.v. administration, respectively.
authors.affiliation: Veterinary Pharmacology and Toxicology Labs, College of Veterinary Medicine, Kyungpook National University, 702-701 Sangyeok-dong, Buk-gu, Daegu, Republic of Korea. parksch@bh.knu.ac.kr
authors.forename: S-C
authors.initials: SC
authors.lastname: Park
authors.forename: H-I
authors.initials: HI
authors.lastname: Yun
mesh_terms: D000042:Absorption; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D001682:Biological Availability; D018592:Cross-Over Studies; D024841:Fluoroquinolones; D005998:Glycine / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D006207:Half-Life; D006736:Horses / Q000378:metabolism*; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D008297:Male; D009643:Norfloxacin / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; C106482:norfloxacin-glycine acetate; D009643:Norfloxacin; D005998:Glycine