The effect of route of administration on the disposition of inulin encapsulated in multilamellar vesicles of defined particle size.

Studies were undertaken to evaluate the effect of multilamellar vesicle (MLV) size and route of administration on the tissue distribution of inulin encapsulated in phosphatidyl choline, cholesterol, phosphatidyl serine and alph tocopherol liposomes. Large (MLV (2.7--4.9 micrometers) administered intravenously delivered a large fraction of the dose to the liver, lungs and spleen. However, when large MLV were given intramuscularly (left thigh muscle), a smaller fraction of the absorbed dose was distributed to these organs. Small MLV (0.3--0.8 micrometers) administered by either route resulted in a smaller fraction of the dose distributing to the liver, lungs and spleen compared to large MLV. In addition, release from the injection site was found to be size-dependent with a larger fraction of the intramuscular dose remaining at 24 hours for the large MLV.