|Title:||Method for producing liposomes with increased percent of compound encapsulated|
|Abstract:||The efficiency of encapsulating a drug into a liposomal formulation is increased by use of a lipid having a carbon chain containing from about 13 to about 28 carbons during preparation of the liposomes. Preferably the liposomes are multivesicular liposomes.|
|Inventor(s):||Ye; Qiang (San Diego, CA), Sankaram; Mantripragada Bhima (San Diego, CA)|
|Assignee:||SkyePharma Inc. (San Diego, CA)|
1. A method for encapsulating at least one biologically active compound in a liposome comprising
a) obtaining a liposome, by any conventional means, having the substance encapsulated therein and having at least one first amphipathic lipid having a carbon chain from about 1 to about 12 carbons in the lipid component of the formulation;
b) determining the percent amount of the encapsulated compound; and
c) substituting said at least one first amphipathic lipid having a carbon chain from about 1 to about 12 carbons in the lipid component of the formulation with at least one second amphipathic lipid with a substantially similar chemical structure having from one to 16 more carbons in a fatty acyl chain of the second lipid;
wherein the resulting percent of the compound encapsulated is from about 0.2 to about 85 percent.
2. The method of claim 1 wherein the liposome is multilamellar.
3. The method of claims 1 wherein the liposome is multivesicular.
4. The method of claim 1 wherein the number of carbons in the amphipathic lipid is in the range from about 14 to 22.
5. The method of claim 2 wherein the amphipathic lipid is selected from the group consisting of
6. The method of claim 2 wherein the amphipathic lipid is saturated.
7. The method of claim 2 wherein the amphipathic lipid is unsaturated.
8. The method of claim 1 wherein subsequent batches of liposome formulations are made by repeating step c).