Abstract
The effects of basic amino acid and sodium salts of diclofenac on the rectal absorption process of ampicillin sodium were studied. All diclofenac salts enhanced the permeation of ampicillin sodium through the membrane in rabbits, rats and dogs. The absorption of ampicillin sodium sigmoidally increased with increase of the concentration of diclofenac salts and the maximum plasma level was attained at 1.5% incorporation for all salts. The permeation of ampicillin sodium increased in the following order ; arginine salt<histidine salt<lysine salt«sodium salt. This order did not change with the animal species studied. From the results of repeated administration experiments, it was found that the leakiness of the barrier induced by diclofenac sodium recovered to the normal condition within about 20 h after the administration, but in the case of diclofenac lysine, the membrane returned to the normal state within only about 6.5 h.
