This study determined if in uitro transfer of drug complexes across the everted rat small intestine would reflect the in uiuo absorption characteristics of the complex. The in uitro transfer of prednisolone in the presence of dimethyl-, diethyl-, dipropyl-, and dibutylpropionamide was in rank-order agreement with the increase in absorption reported previously from an in situ preparation. Excellent agreement was found between the in uitro and in situ absorption of prednisolone in the presence of various concentrations of dipropylpropionamide. The interaction of atropine with eosin-B, which has been reported not to increase the transfer of the dye across the everted rat intestine, was found to have no effect on absorption from an in situ preparation. The difference in effect of complexation on drug transfer across the everted rat intestine may be related to a difference in rate-limiting barriers for prednisolone and eosin-B.
Keyphrases
Drug complexes-in uitro transfer as an indicator of in uiuo absorption characteristics 0 Dialkylpropionamides-effect on absorption of prednisolone, everted rat intestine, in uitro preparation as an indicator of absorption-enhancing characteristics of complex Complexes (dialkylpropionamides-prednisolone) -in uitro transfer as an indicator of in uiuo absorption characteristics ' Huntingdon Farms, Conshohocken, Pa Coleman 124 spectrophotometer.