Evaluation of dipalmitoylphosphatidylcholine liposomes containing a soybean-derived sterylglucoside mixture for liver targeting.

We investigated multilamellar vesicle (MLV) liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and a soybean-derived sterylglucoside mixture (SG) (DPPC/SG-liposomes) for targeting liver parenchymal cells after administration via the tail vein in mice, using liposome-entrapping calcein. The accumulation of DPPC/SG(7:2, mole ratio, DPPC:SG = 7:2)-liposomes in the liver was the highest among DPPC/SG-liposomes. About 80% and 40% of the dose of DPPC/SG(7:2)-liposomes accumulated in the liver at 15 min and 2 h, respectively, but about 20% of DPPC/SG(7:3.5, 7:7)-liposomes accumulated at 2 h after an intravenous administration. However, the uptake of DPPC/SG(7:2, 7:3.5, 7:7)-liposomes by liver parenchymal cells was about 7 times greater than that in non-parenchymal cells irrespective of the SG concentration in liposomes. The uptake of DPPC/SG(7:2)-liposomes in liver was almost the same level as that by liposomes containing lactocylceramide (LC) (LC-liposomes) that were already known to be taken up in liver parenchymal cells by the asialoglycoprotein receptor. DPPC/SG(7:2)-liposomes effectively targeted liver, having optimal stability and SG.