Hybrid paucilamellar lipid vesicles

Claim 1

Hybrid paucilamellar lipid vesicles having both a first lipid and a second lipid as structural materials in the lipid bilayers, said vesicle containing 2-10 lipid bilayers in the form of concentric substantially spherical shells, the innermost of said lipid bilayers enclosing a substantially amorphous central cavity, said vesicle bilayers comprising: 10 to 30% of said first lipid selected from a group consisting of phospholipids, glycolipids, and mixtures thereof; and 49 to 75% of second lipid, said second lipid being a nonphospholipid, nonglycolipid surfactant selected from the group consisting of diethanolamides having the formula (HOCH.sub.2 --CH.sub.2).sub.2 NCO--R.sub.2 where R 2 is a residue derived from a carboxylic acid selected from the group consisting of caprylic, lauric, myristic, stearic, and linoleic acid; long chain acyl hexosamides having the formula R.sub.4 --NHCO--(CH.sub.2).sub.b --CH.sub.3 where b ranges from 10-18 and R 4 is a residue derived from a sugar molecule selected from a group consisting of glucosamine, galactosamine, and N-methylglucamine; long chain acyl amino acid amides having the formula R.sub.5 --CHCOOH--NHCO--(CH.sub.2).sub.c --CH.sub.3 where c ranges from 10-18 and R 5 is an amino acid side chain; long chain acyl amides having the formula HOOC--(CH.sub.2).sub.d --N(CH.sub.3).sub.2 --(CH.sub.2).sub.3 --NCO--R.sub.6 where R 6 is an acyl chain having 12-20 carbons and not more than two unsaturations, and d ranges from 1-3; glycerol monostearate; sarcosinamides having the formula ##STR4## where R 7 is selected from the group consisting of single-chain carbonyl derivatives of C 12 -C 20 fatty acids; and betaines having the formula ##STR5## where R 8 is a residue of a long-chain fatty acid ester.

Claim 13

A method of making hybrid paucilamellar lipid vesicles comprising the steps of: forming a lipid phase by blending a first lipid selected from the group consisting of phospholipids, glycolipids, and mixtures thereof, with a second lipid selected from the group consisting of nonphospholipid, nonglycolipid non-ionic, zwitterionic, and anionic surfactants, and mixtures thereof, and with any other lipophilic molecules to be incorporated into the lipid bilayers of said vesicles; forming an aqueous phase by blending an aqueous-based solution and any aqueous soluble materials to be incorporated into said vesicles; and shear mixing said lipid phase and said aqueous phase to form said hybrid vesicles without the formation of a separable lamellar phase.

Claim 14

A method of making hybrid paucilamellar lipid vesicles comprising the steps of: forming a lipid phase by blending a first lipid selected from the group consisting of phospholipids, glycolipids, and mixtures thereof, with a second lipid selected from the group consisting of nonphospholipid, nonglycolipid non-ionic, zwitterionic, and anionic surfactants, and mixtures thereof, and with any other lipophilic molecules to be incorporated into the lipid bilayers of said vesicles; forming an aqueous phase by blending an aqueous-based solution and any aqueous soluble materials to be incorporated into said vesicles; and shear mixing said lipid phase and said aqueous phase to form said hybrid vesicles without the formation of a separable lamellar phase.