Pharmacokinetics of benzydamine in dairy cows following intravenous or intramuscular administration.
Five lactating cows were given benzydamine hydrochloride by rapid intravenous (0.45 mg/kg) and by intramuscular (0.45 and 1.2 mg/kg) injection in a crossover design. The bioavailability, pharmacokinetic parameters and excretion in milk of benzydamine were evaluated. After intravenous administration, the disposition kinetics of benzydamine was best described using a two-compartment open model. Drug disposition and elimination were fast (t1/2 alpha: 11.13 +/- 3.76 min; t1/2 beta: 71.98 +/- 24.75 min; MRT 70.69 +/- 11.97 min). Benzydamine was widely distributed in the body fluids and tissues (Vd(area): 3.549 +/- 1.301 L/kg) and characterized by a high value for body clearance (33.00 +/- 5.54 ml/kg per min). After intramuscular administration the serum concentration-time curves fitted a one-compartment open model. Following a dose of 0.45 mg/kg, the Cmax value was 38.13 +/- 4.2 ng/ml at a tmax of 67.13 +/- 4.00 min; MAT and MRT were 207.33 +/- 22.64 min and 278.01 +/- 12.22 min, respectively. Benzydamine bioavailability was very high (92.07% +/- 7.08%). An increased intramuscular dose (1.2 mg/kg) resulted in longer serum persistence (MRT 420.34 +/- 86.39 min) of the drug, which was also detectable in milk samples collected from both the first and second milking after treatment.
Anfossi
P
P
Istituto di Farmacologia, Farmacocinetica e Tossicologia, Facoltà di Medicina Veterinaria, Università degli Studi di Bologna, Italy.
Malvisi
J
J
Catraro
N
N
Bolognini
M
M
Tomasi
L
L
Stracciari
G L
GL
D000818:Animals; D001591:Benzydamine / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D005260:Female; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D007774:Lactation; D008657:Metabolic Clearance Rate; D008892:Milk / Q000378:metabolism; D008954:Models, Biological
D001591:Benzydamine