Pharmacokinetics,Tissue Distribution and Metabolism of Intravenously Administered Digalactosyldiacylglycerol and Monogalactosyldiacylglycerol in the Rat |
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Abstract: | AbstractA bilayer forming galactolipid, digalactosyldiacylglycerol (DGalDG) has been identified as a tool with suitable physicochemichal properties for pharmaceutical formulation work. One possible application is as a carrier for liposome entrapped drugs for intravenous administration. The fate of intravenously administered galactolipids is not known. In this study liposomal dispersions of galactolipids, containing 3H]fatty acid labelled DGalDG or monogalactosyldiacylglycerol (MGalDG) were injected intravenously in the rat and the disappearance from blood and uptake by tissues were examined. The T1/2 of 3H]DGalDG in plasma was 3 to 5 minutes. Of the tissues examined (liver, spleen, kidneys, lung, heart, stomach, upper and lower small intestine and colon), the liver contained the highest radioactivity per g tissue after both 15 min. and 4 h. Autoradiographic examinations after 15 min, 1 h and 4 h showed that the uptake of radiolabeled DGalDG and MGalDG occurred mainly to the hepatocytes. Less than 6 % of the injected 3H]DGalDG remained in liver and plasma as 3H]DGalDG after 4 h. 3H]MGalDG exhibited a similar pattern of metabolism although the initial disappearance rate was faster than for 3H]DGalDG. The study thus shows that the hepatocytes take up and hydrolyse galactolipids after intravenous administration. |
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Keywords: | Digalactosyldiacylglycerol Monogalactosyldiacylglycerol Galactolipids liposomes Metabolism (Rat) |
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