[The carrier potential of liposomes for methotrexate. Changing of the tissue levels of methotrexate in the organs of mice (author's transl)].

Drugs entrapped in liposomes (artificial lipid vesicles) exhibit different pharmacokinetics after intravenous application than drugs injected in a free form. The folidacidantagonist methotrexate can be entrapped in liposomes in a therapeutically useful concentration (0.5 mg MTX/ml) and can be stored with high stability of entrappment. After intravenous injection into the tail vein of mice liposomes entrapped methotrexate is found more enriched in cell systems with high rate of endocytosis and not eliminated by the kidneys within 3 h like free methotrexate. It can be shown, that for the organs liver, spleen, kidney, gut, lung, and blood over a 6 h period liposomes entrapped methotrexate is enriched in the tissues and that for example after 6 h the methotrexate level in the liver is 20 fold higher in comparison to free injected methotrexate.