An experimental assessment of the Wagner-Sedman extraction theory for the intestinal absorption of antibacterial sulfonamides.

The chromatographic parameters in a reverse-phase partition system and the rat gut in situ absorption rate constants for 18 antibacterial sulfonamides are highly correlated values. The correlation is logarithmic-logistic in nature, being in accordance with the Wagner-Sedman extraction theory for a constant pH value. Parabolic correlations did not satisfactorily fit the experimental data. This behavior, not frequently reported in regard to the intestinal absorption of drugs, is discussed in connection with other apparently contradictory available data.