IN-VITRO CHARACTERIZATION OF CIPROFLOXACIN DISTRIBUTION IN RAT LUNG

The binding of ciprofloxacin to both lung homogenate and isolated subc ellular fractions, as well as the washout kinetics from lung homogenat e of rats, was studied in vitro. Differences iri :he binding capacity of ciprofloxacin to subcellular fractions and total lung homogenate we re observed. In vitro mean partition coefficient values (+/- SD) for n uclear; mitochondrial and microsomal fractions were 2.84 +/- 0.82, 2.3 2 +/- 0.69 and 2.72 +/- 0.75, respectively, with no statistical differ ences among these values. On the other hand, the partition coefficient obtained with lung homogenate showed a mean value (+/- SD) of 1.39 +/ - 0.31, statistically lower than the values corresponding to the diffe rent cellular fractions. These results reveal a great affinity of cipr ofloxacin for intracellular structures that may condition the distribu tion characteristics of the quinolone in lung and other body tissues. In washout studies, washout of ciprofloxacin from lung homogenate prov ed to be a monoexponential and first-order kinetic processes. (C) 1998 Prous Science. All rights reserved.