摘要：Ceramide sulfate (N-acylsphingosine-1-O-sulfate), which lacks the galactose residue of sulfatide, was examined as a possibly preferable constituent of liposomes for drug delivery. Multilamellar vesicles prepared from phosphatidylcholine, cholesterol, and N-lignoceroylsphingosine-1-O-sulfate in a molar ratio of 5 : 4 : 1 efficiently entrapped adriamycin, and the retention of the drug in the liposomes in saline at 4°C for 8d was nearly 100%. In terms of entrapment efficiency and retention of the drug in liposomes, N-lignoceroylsphingosine-1-O-sulfate was superior to N-stearoylsphingosine-1-O-sulfate. A pharmacodynamic study revealed that the blood level of adriamycin was far higher with the drug encapsulated in N-lignoceroylsphingosine-1-O-sulfate-containing liposomes than with the free drug. The drug level in the heart was remarkably reduced with the liposome-entrapped drug, which is advantageous in reducing the cardiotoxicity of this drug. The effect of N-lignoceroylsphingosine-1-O-sulfate-containing liposomes on the blood level of adriamycin was superior to that of sulfatide-containing liposomes, though the effect of the former on the heart level was comparable to that of the latter. The tumoricidal effect on ascitic P388 leukemia and Lewis lung carcinoma was higher with adriamycin entrapped in N-lignoceroylsphingosine-1-O-sulfate-containing liposomes than with the free drug.
