STUDY ON THE RECTAL ABSORPTION OF GENTAMICIN IV

Gentamicin suppository containing surfactant was administered to beagle dogs (adult and aged) for 6 consecutive days, once daily, in order to examine the change of blood level of gentamicin. When polyoxyethylene (20) cetyl ether, having a rather mild effect, was used as the surfactant, the change in the blood level of gentamicin was similar in both adult and aged dogs, showing almost the same bioavailability for 6 consecutive days. However, the administration of saponin, capable of destroying the cell membrane to considerably extent, influenced the C.a. after 4 th day administration in both adult and aged dogs. So, we could not obtain constant bioavailability of GM when saponin was used as the absorption promoter.