Abstract
Effect of various types of surface-active agents on the rectal absorption of sulfisoxazole from cocoa butter was investigated by the blood level determination with rabbits. Blood levels were in general increased with increase of surface-active agent, and decreased by addition of the large amount. Surface-active agent accelerated the release of the drug from the base to dissolution medium. On the other hand, surface-active agent reduced the absorption rate of the drug from aqueous solution. These results suggest that the increase of the drug absorption at the low concentrations of surface-active agents is due to release acceleration, but the reduction effect on drug absorption in their higher concentrations is due to predominance of absorption reduction over release acceleration. Cetyltrimethyl ammonium bromide especially stimulated the drug absorption in the very low concentrations.
