Pharmacokinetic study of flunixin and its interaction with enrofloxacin after intramuscular administration in calves

The Pharmacokinetic aspects of flunixin (FL) administered alone and in combination with enrofloxacin (EN), were studied in clinically healthy calves. The experiments were performed on two groups: FL alone {2.2 mg/kg,intramuscular (IM)}, and combination of FL (2.2 mg/kg, IM) and EN {2.5 mg/kg, IM}. Plasma concentrations of FL were determined using High Performance Liquid Chromatography (HPLC) method. Moreover, the effects of FL alone or in combination on liver and kidney functions were also assessed. Flunixin was rapidly absorbed intramuscularly with a half-life of absorption (t ) of 0.094 h and the peak plasma concentration (C ) was 1.27 g/mL was attained after 1/2ab max 0.49 h (T ). Enrofloxacin significantly altered the pharmacokinetics of FL by delaying its absorption and accelerate its max elimination from body. Significant increases (32%) in the area under the curve (AUC) and (37%) in the elimination rate constant (K ) from the central compartment and a significant decrease (27%) in the elimination half-life (t ) of FL el 1/2el were found following coadministration with EN, compared with administration of FL alone. The maximum plasma drug concentration (C ) showed significant increase (28%) following the coadministration of EN with FL as max compared to that following the administration of FL alone. It was concluded that the combination of FL and EN negatively altered the kinetics of FL and exaggerated the adverse effect on hepato-renal function in calves consequently; the concomitant use of FL and EN should be avoided in calves. [Vet. World 2011; 4(10.000): 449-454

Bions: A Family of Biomimetic Mineralo-Organic Complexes Derived from Biological Fluids

Mineralo-organic nanoparticles form spontaneously in human body fluids when the concentrations of calcium and phosphate ions exceed saturation. We have shown previously that these mineralo-organic nanoparticles possess biomimetic properties and can reproduce the whole phenomenology of the so-called nanobacteria—mineralized entities initially described as the smallest microorganisms on earth. Here, we examine the possibility that various charged elements and ions may form mineral nanoparticles with similar properties in biological fluids. Remarkably, all the elements tested, including sodium, magnesium, aluminum, calcium, manganese, iron, cobalt, nickel, copper, zinc, strontium, and barium form mineralo-organic particles with bacteria-like morphologies and other complex shapes following precipitation with phosphate in body fluids. Upon formation, these mineralo-organic particles, which we term bions, invariably accumulate carbonate apatite during incubation in biological fluids; yet, the particles also incorporate additional elements and thus reflect the ionic milieu in which they form. Bions initially harbor an amorphous mineral phase that gradually converts to crystals in culture. Our results show that serum produces a dual inhibition-seeding effect on bion formation. Using a comprehensive proteomic analysis, we identify a wide range of proteins that bind to these mineral particles during incubation in medium containing serum. The two main binding proteins identified, albumin and fetuin-A, act as both inhibitors and seeders of bions in culture. Notably, bions possess several biomimetic properties, including the possibility to increase in size and number and to be sub-cultured in fresh culture medium. Based on these results, we propose that bions represent biological, mineralo-organic particles that may form in the body under both physiological and pathological homeostasis conditions. These mineralo-organic particles may be part of a physiological cycle that regulates the function, transport and disposal of elements and minerals in the human body