Faculty of Veterinary Medicine University of Zagreb
Abstract
The disposition of cefpirome after single intramuscular (i.m.) administration (10 mg.kg-1) was investigated in five male cross-bred calves and in vitro plasma protein binding was determined. The concentration of cefpirome in the plasma was estimated by the microbiological assay technique. Binding of cefpirome to plasma proteins was determined at different concentration levels by the equilibrium dialysis technique. The peak plasma level of cefpirome after i.m. administration to cattle was attained at 45 min post-dose and the drug was detected in plasma above MIC of 0.5 μg.mL-1 for up to 10 h. The drug disposition followed a one-compartment open model. The values of t1/2Ka, t1/2β and AUC were 0.21 ± 0.01 h, 2.06 ± 0.02 h and 31.7 ± 0.95 μg.mL-1.h, respectively. Cefpirome was bound to the plasma proteins to the extent of 26.0 ± 2.84 percent at the concentration range of 1-100 μg.mL-1. The binding capacity of cefpirome to plasma proteins and the dissociation rate constant of the protein-drug complex were 3.71 ×10-8 ± 0.31 ×10-8 mole.g-1 and 3.43 ×10-7 ± 0.46 ×10-7 mole, respectively.Istražena je raspodjela cefpiroma i njegovo in vitro vezanje na proteine plazme u petero muške bivolje teladi nakon jednokratne intramuskularne primjene u dozi od 10 mg/kg. Koncentracija cefpiroma u plazmi bila je procijenjena pomoću mikrobioloških testova. Njegovo vezanje na proteine plazme određeno je za različite koncentracije pomoću dijalize. Vršna razina cefpiroma u plazmi nakon intramuskularne primjene postignuta je 45 minuta nakon davanja, a lijek je u plazmi bio dokazan iznad MIC od 0,5 μg/mL do 10 sati nakon davanja. Raspodjela lijeka bila je sukladna modelu otvorenosti jednog odjeljka. Vrijednost t1/2Ka iznosila je 0,21 ± 0,01 h, t1/2β 2,06 ± 0,02 h, a AUC 31,7 ± 0,95 μg/mL/h. Cefpirom se vezao na proteine plazme u visini od 26,0 ± 2,84 % u razmaku koncentracije od 1-100 μg/mL. Sposobnost vezanja cefpiroma na proteine plazme bila je 3,71 ×10-8 ± 0,31 ×10-8 mol/g, a konstanta njegova oslobađanja od kompleksa protein-lijek iznosila je 3,43 ×10 7± 0,46 ×10-7 mola
