| abstract |
Substantially cholesterol-free liposomes are provided which demonstrate improved drug retention in vivo. These liposomes may comprise: (a) at least 60 mol.% of a phospholipid comprising two saturated fatty acids, the acyl chain of each being the same or different, at least one of said acyl chains having more than 18 carbon atoms; (b) from about 2 to about 15 mol.% hydrophilic polymer-conjugated lipids; and (c) up to about 38 mol.% of one or more vesicle-forming lipids. Specific embodiments of this invention are liposomes encapsulating idarubicin or topotecan and demonstrating improved drug retention. Also provided is a method for determining whether retention of a particular drug may be improved by this invention. |