The purpose of the present study was to assess two recently described models (S-L_w-L_o and S-L_w-in situ) for the prediction of drug absorption behavior in vivo following dissolution from a compressed tablet. The experiments were carried out by using 11 sulfonamides as test compounds to survey the validity of the models. In the S-L_w-L_o model, the drug appearance in the aqueous phase, C_w, and in the organic phase, C_o, obeyed first order kinetics from 0 to 6 h. In the S-L_w-in situ model, the drug disappearance in the reservoir, (C_w-C_i)^t, and change in blood levels of the drug, C_b^t, with respect to time were analyzed simultaneously, and the factors affecting the drug absorption are discussed on the basis of the physicochemical and pharmacokinetic properties of the drug. It was found that the C_o^t value was significantly correlated with both (C_w-C_i)^t and C_b^t values. The C_o^t values were also correlated well with the blood levels of the drug in vivo following oral administration to rabbits. The results indicated that the two experimental models are useful to predict the absorption behavior of drugs and their usefulness may be extended to the evaluation of oral bioavailability.