Abstract
The enhancing action of sodium salicylate on rectal ampicillin absorption in rabbits showed a strong dependency on the concentration of sodium salicylate in the administered solution. Maximum bioavailability of ampicillin obtained when increasing sodium salicylate concentration was 60 to 70%. Although maximum bioavailability of ampicillin administered as a suppository was also 60 to 70%, the suppository formulation required a significantly lower dose of sodium salicylate compared to the solution, suggesting that the effective fluid volume available to dissolve drugs in rabbits might be very small. Further, sodium ion might enhance the adjuvant action of sodium salicylate.
