Abstract
A predicting method for the intestinal absorption of drugs by measuring their physicochemical properties such as organic solvent / buffer partition coefficient, molecular volume (molecular weight), hydrogen bonding and diffusion rate across silicone membrane was investigated. A poor correlation was observed between absorption rate from intestinal lumen and organic solvent / buffer partition coefficient of tested drugs. On the contrary, good regression coefficient (R = 0.801) was obtained when the three factors (molecular weight, hydrogen bonding, and permeation rate across silicone membrane) were used. On the other hand, the excellent regression was observed when the drugs were classified into anionic, cationic, and neutral groups. These results suggest that the permeation rate across silicone membrane, molecular weight, and hydrogen bonding are valuable measures for predicting the absorption behavior of drugs. Moreover, an additional parameter which reflects the effect of the molecular charge will be necessary.
