Abstract
Absorption characteristics of highly lipid-soluble dyes from oil-in-water emulsions was studied in the rat small intestine. Short-chain triglyceride or long-chain triglyceride was chosen as an oil phase and absorption of oils as well as dyes (Oil Red XO and Sudan Black B) was investigated using in situ loop method. From emulsions using tributyrin as an oil phase, Oil Red XO was absorbed monoexponentially to the same extent as from Polysorbate-80 micellar solution despite the fact that the dye is very lipophilic and is not considerable to be localized in the aqueous phase. On the other hand, from emulsions using triolein as an oil phase, Oil Red XO was absorbed faster in the early stage and slower in the later stage than from tributyrin emulsions. These absorption characteristics of Oil Red XO was demonstrated as the reflection of that of oils. Oil Red XO does not seem to move into inner compartments with oil, for it was not transported into intestinal lymph even from triolein emulsions.
