Pharmacokinetics, urinary excretion and plasma protein binding of danofloxacin following intravenous administration in buffalo calves (Bubalus bubalis)

Abstract

Pharmacokinetics, urinary excretion and plasma protein binding of danofloxacin was investigated in buffalo calves following intravenous administration at the dose rate of 1.25 mg/kg to select the optimal dosage regimen of danofloxacin. Drug concentrations in plasma and urine were measured by microbiological assaying. In vitro plasma protein binding was determined employing the equilibrium dialysis technique. The distribution and elimination of danofloxacin were rapid, as indicated by values (mean +/-SD) of distribution half-life (t(1/2)alpha = 0.16 +/- 0.07 h) and elimination half-life (t(1/2)beta = 4.24 +/- 1.78 h), respectively. Volume of distribution at steady state (Vss) = 3.98 +/- 1.69 L/kg indicated large distribution of drug. The area under plasma drug concentration versus time curve (AUC) was 1.79 +/- 0.28 micrg/ml x h and MRT was 8.64 +/- 0.61 h. Urinary excretion of danofloxacin was 23% within 48 h of its administration. Mean plasma protein binding was 36% at concentrations ranging from 0.0125 microg/ml to 1 microg/ml. On the basis of pharmacokinetic parameters obtained, it is concluded that the revision of danofloxacin dosage regimen in buffalo calves is needed because the current dosage schedule (1.25 mg/kg) is likely to promote resistance.

Pharmacokinetics and distribution in interstitial and pulmonary epithelial lining fluid of danofloxacin in ruminant and preruminant calves

“…Similar estimates of danofloxacin protein binding were reported in buffalo calves (36% at concentrations ranging from 0.0125 μg/mL to 1 μg/mL). (Sappal et al ., ). A strong nonlinear binding has already been reported by Friis et al .…”

Pharmacokinetics of enrofloxacin and danofloxacin in premature calves

“…The binding ratio of DNX to plasma proteins in premature calves was not determined in this study. However, the activity of protein binding of DNX has been reported as 36% in calves (Sappal, Chaudhary, Sandhu, & Sidhu, ). The total amount of plasma protein in human neonates is lower than that of adults, leading to an increase in the amount of free drug (Grandison & Boudinot, ).…”

“…The binding ratio of DNX to plasma proteins in premature calves was not determined in this study. However, the activity of protein binding of DNX has been reported as 36% in calves (Sappal, Chaudhary, Sandhu, & Sidhu, 2009).…”

Pharmacokinetic behavior and pharmacokinetic/pharmacodynamic indices of marbofloxacin after intravenous, subcutaneous, and intramuscular administrations in buffalo calves (<10 days old)

“…, 2003; Goudah et al. , 2007; Sappal et al. , 2009), and no data about the kinetic behavior of these drugs in neonatal buffaloes are available.…”

“…The absence of pharmacokinetic studies in buffaloes obligates the clinician to practice empirical assays based on allometric calculations or to extrapolate the dosage from other species, especially from cattle. Only a few studies relating to the pharmacokinetics of fluoroquinolones have been performed in buffaloes (Kumar et al, 2003;Goudah et al, 2007;Sappal et al, 2009), and no data about the kinetic behavior of these drugs in neonatal buffaloes are available. In this age-group, the most frequently occurring clinical problems are diarrhea, pneumonia, and pneumoenteritis and usually represent an economic disaster of nursing and weaning calves (Khan & Khan, 1997;Borriello et al, 2010;Bukhari et al, 2010).…”