Pharmacokinetics and bioavailability of moxifloxacin in calves following different routes of administrations.
BACKGROUND
Moxifloxacin is a new fourth-generation 8-methoxy fluoroquinolone developed primarily for the treatment of community-acquired pneumonia and upper respiratory tract infections. The aim of the study was to investigate the plasma pharmacokinetics characteristic of moxifloxacin in calves, after intravenous, intramuscular and subcutaneous administration of a single dose. Meanwhile, plasma protein binding and bioavailability of moxifloxacin were also estimated.


METHODS
Plasma concentrations of moxifloxacin were measured using a modified HPLC method, and the extent of plasma protein binding was determined in vitro using ultrafiltration.


RESULTS
Following intravenous administration, the half life of elimination, the volume of distribution at steady state and the area under the curve were 3.29 h, 0.94 l/kg and 24.72 microg x h/ml, respectively. After intramuscular and subcutaneous administration of moxifloxacin at the same dose, the peak plasma concentrations were 2.41 and 2.20 microg/ml and were obtained at 1.54 and 1.59 h, respectively. The systemic bioavailabilities were 87.19 and 75.94%, respectively. The in vitro plasma protein binding of moxifloxacin in plasma of calves was 27%.


CONCLUSIONS
A high peak plasma concentration, area under the curve, rapid absorption and bioavailability following intramuscular and subcutaneous administration characterize the pharmacokinetics of moxifloxacin in calves.
Goudah
A
A
Pharmacology Department, Faculty of Veterinary Medicine, Cairo University, Giza, Egypt. aymangouda@yahoo.com
Hasabelnaby
S
S
D000818:Animals; D000890:Anti-Infective Agents / Q000097:blood / Q000493:pharmacokinetics*; D001372:Aza Compounds / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D002417:Cattle / Q000097:blood*; D024841:Fluoroquinolones; D006207:Half-Life; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D007279:Injections, Subcutaneous; D000077266:Moxifloxacin; D011804:Quinolines / Q000097:blood / Q000493:pharmacokinetics*
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D000077266:Moxifloxacin