Sparfloxacin binds to rabbit intestinal brush-border membrane vesicles by ionic interactions

The intestinal transport and binding of sparfloxacin has been investigated using rabbit intestinal brush-border membrane vesicles. The apparent uptake of sparfloxacin by these vesicles was very rapid. The plateau was reached after 20 min in NaCl-free buffer with a membrane binding of this drug accounting for about two-thirds of the apparent accumulation. Addition of NaCl did not affect the transport of this fluoroquinolone into the intravesicular space. However, the binding of sparfloxacin to membrane vesicles was sharply reduced by NaCl, suggesting that the binding of sparfloxacin to epithelial cells involves ionic interactions. (C) 1997 Elsevier Science B.V.