Lipophilic drug absorption lymphatic transport

After absorption, most drugs and xenobiotics traverse the enterocyte and are absorbed into the portal blood. A small number of highly lipophilic drugs, however, are transported to the systemic circulation by means of the intestinal lymphatics. 

The oil represents one of the most important components in the formulation of the microemulsion. It can solubilize the required dose of the lipophilic drug and can also increase the fraction of lipophilic drug transported via the intestinal lymphatic system, thereby increasing absorption from the GI tract, depending on the molecular nature of the triglyceride. ... 

Microemulsions are transparent systems of two immiscible fluids, stabilized by an interfacial film of surfactant or a mixture of surfactants, frequently in combination with a cosurfactant. These systems could be classified as water-in-oil, bicontinuous, or oil-in-water type depending on their microstructure, which is influenced by their physicochemical properties and the extent of their ingredients. - SMEDDSs form transparent microemulsions with a droplet size of less than 50 nm. Oil is the most important excipient in SMEDDSs because it can facilitate self-emulsification and increase the fraction of lipophilic drug transported through the intestinal lymphatic system, thereby increasing absorption from the gastrointestinal tract. Long-chain and medium-chain... 

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