Kinetic Analysis of the Peritoneal Transport of Quinolonecarboxylic Acids in Rats

In order to describe quantitatively the peritoneal transport of quinolonecarboxylic acids (quinolones), we employed a kinetic model based on the hydrodynamic pore theory of transcapillary exchange, which involves the changes in the volume and osmolality of the dialysate as well as the diffusion and convection of drugs across the peritoneum. Among the quinolones, we tested cinoxacin, enoxacin, norfloxacin, ofloxacin and a new quinolone, NY-198. The observed data on the osmolality, volume and drug concentration in the dialysate (hypertonic and hypotonic) after intraperitoneal administration were analyzed according to the kinetic model to estimate the hydrodynamic parameters of peritoneal transport, i.e., apparent capillary membrane permeability and the reflection coefficient, of each drug by a computer-aided curve-fitting procedure. It was found that the peritoneal transport of the quinolones examined was diffusion-limited and was not affected by the tonicity of the dialysate, indicating that solvent drag played a minor role in the peritoneal transport of these drugs.