FURTHER INVESTIGATIONS INTO ABSORPTION OF DEXTROMETHORPHAN FROM RATS STOMACH

Dextromethorphan has been shown to be absorbed by a passive diffusion mechanism from the rat' stomach as a protonated species. Using buffers of a constant pH 2.0, it was found that the absorption rate depended on the anionic species of the buffer, but experiments with 14C‐labeled trichloroacetate buffers suggested that the drug was not absorbed as the lipid‐soluble ion pair. Good correlation between the surface activity of the drug solutions and the corresponding absorption rates was observed. Copyright © 1969 Wiley‐Liss, Inc., A Wiley Company