Patent ID: 6180137
Filing Date: 2001-01-30
Classification: A61K,Y10T

Abstract:
A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a liposome, the liposome comprising:a lipid bilayer which comprises: (a) a phosphatidylcholine; (b) a sterol; (c) a headgroup derivatized lipid comprising a phosphatidylethanolamine linked at the ethanolamine group to a moiety selected from the group consisting of dicarboxylic acids, polyethylene glycols, gangliosides and polyalkyl ethers; and, (d) an etherlipid having the formula: ##STR5##wherein:R.sub.1 is Y.sub.1 Y.sub.2, Y.sub.2 is CH.sub.3 or CO.sub.2 H, Y.sub.1 is (CH.sub.2).sub.n1 (CH.dbd.CH).sub.n2 (CH.sub.2).sub.n3 (CH.dbd.CH).sub.n4 (CH.sub.2).sub.n5 (CH.dbd.CH).sub.n6 (CH.sub.2).sub.n7 (CH.dbd.CH).sub.n8 (CH.sub.2).sub.9, the sum of n.sub.1 +2n2+n3+2n4+n5+2n6+n7+2n8+n9 is an integer of from 3 to 23, n1 is equal to zero or is an integer of from 1 to 23, n3 is equal to zero or is an integer of from 1 to 20, n5 is equal to zero or is an integer of from 1 to 17, n7 is equal to zero or is an integer of from 1 to 14, n9 is equal to zero or is n integer of from 1 to 11, and each of n2, n4, n6 and n8 is independently zero or 1;Z is oxygen or sulfur; and,the headgroup-derivatized lipid comprises from about 5 mole percent to about 20 mole percent of the liposome's lipid bilayer and the etherlipid comprises from greater than about 10 mole percent to less than about 30 mole percent of the bilayer.