Absorption of various drugs through the rabbit's respiratory mucosa in vitro.

The absorption of doxycycline (DOTC), bekanamycin (AKM), cefazolin (CEZ), penicillin G (PC-G), prednisolone, and human IgG through the rabbit's tracheal mucosa was examined using the double-chamber method. The results indicate that the tracheal mucosa can absorb both small molecules and macromolecules. Passing through the intercellular space, DOTC, a small molecule, was absorbed through the tracheal epithelium by diffusion. Human IgG, a macromolecule, was absorbed by the mechanism of an energy-consuming transport process. This study of the absorption of drugs through the respiratory mucosa could open up new areas in the utilization of intrarespiratory administration of drugs and lead to a better understanding of the mechanisms involved in respiratory allergies.