Lipid vehicles for intestinal lymphatic drug absorption.

The lipoprotein fractions in mesenteric lymph were monitored following intraduodenal administration of arachis oil and oleic, linoleic and linolenic fatty acids to rats. An increase in the chylomicron fraction, but not the VLDL or LDL fraction, was observed with each lipid. The greater the degree of unsaturation of the fatty acid, the more rapid the onset of chylomicron synthesis. The administration of linoleic acid and arachis oil produced the highest concentration of chylomicrons in the lymph. These results reflect differences in the rate of absorption and biochemical metabolism of the lipids and have implications for the selection of vehicles for the delivery of drugs by the lymphatic route.