Development of wrapped liposomes: novel liposomes comprised of polyanion drug and cationic lipid complexes wrapped with neutral lipids.
Novel wrapped liposomes comprised of polyanion drug and cationic lipid complexes wrapped with neutral lipids were prepared using an efficient, innovative procedure. In this study, dextran fluorescein anionic (DFA) was used as an example of a polyanionic compound. During the process, neutral lipids accumulated around the complexes and eventually covered the complexes. The resulting liposomes were 120-140 nm in diameter and the encapsulation efficiency was up to 90%. In fetal bovine serum, DFA/cationic lipid complexes degraded rapidly but the wrapped liposomes were considerably more stable. Following intravenous administration to rats, DFA/cationic lipid complexes were rapidly eliminated whereas the wrapped liposomes exhibited a much longer blood half-life. These data suggest that DFA is located on the surface of the complexes, but DFA is present inside the wrapped liposomes. The drug-delivery properties of the wrapped liposomes established in the present study suggests that formulations based on this technology could offer important advantages for the administration of many types of drug including antisense oligonucleotides, plasmids and siRNAs which may therefore lead to improved therapeutic effectiveness of this range of drugs. The method of preparation of the wrapped liposomes is so simple that it should be straightforward to adapt to a manufacturing scale.
Drug Formulation Research Laboratories, Pharmaceutical Research Center, Kyowa Hakko Kogyo Co., Ltd., 1188, Shimotogari, Nagaizumi-Cho, Sunto-Gun, Shizuoka 411-8731, Japan. masahiro.yamauchi@kyowa.co.jp
Masahiro
M
Yamauchi
Hiroko
H
Kusano
Etsuko
E
Saito
Takeshi
T
Iwata
Masashi
M
Nakakura
Yasuki
Y
Kato
Noboru
N
Aoki
D000818:Animals; D002412:Cations / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D003911:Dextrans / Q000737:chemistry; D016503:Drug Delivery Systems / Q000379:methods*; D004355:Drug Stability; D000431:Ethanol / Q000737:chemistry; D019793:Fluorescein / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry*; D008297:Male; D008854:Microscopy, Electron; D008954:Models, Biological; D009696:Nucleic Acids / Q000737:chemistry; D010455:Peptides / Q000737:chemistry; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry*; D051381:Rats; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D013997:Time Factors
D002412:Cations; D003911:Dextrans; D000431:Ethanol; D019793:Fluorescein; D008055:Lipids; D008081:Liposomes; D009696:Nucleic Acids; D010455:Peptides; D000071228:Polyelectrolytes; D011108:Polymers; D012965:Sodium Chloride