title: Ammonium ion level in serum affects doxorubicin release from liposomes.
abstract: In this study, we measured the release of drug from liposome-encapsulated doxorubicin (DXR) in human and mouse serum. While human serum did not induce DXR-release, mouse serum significantly induced DXR-release in a temperature- and time-dependent manner. Release of DXR was clearly observed in ultrafiltrated mouse serum, indicating that low-molecular substances affect DXR-release. Therefore, the level of Na+, Cl(-), NH4+, and urea nitrogen in each type of serum was measured. Only the concentration of NH4+ in mouse serum was significantly higher than that in human serum. Furthermore, addition of ammonium acetate to human serum induced DXR release at the same level observed in mouse serum. These results indicate that the NH4+ concentration in serum might greatly affect the release of DXR from liposomes.
authors.affiliation: Division of Drugs, National Institute of Health Sciences, Tokyo, Japan. h-shibata@nihs.go.jp
authors.forename: H
authors.initials: H
authors.lastname: Shibata
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: C
authors.initials: C
authors.lastname: Yomota
authors.forename: T
authors.initials: T
authors.lastname: Kawanishi
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000008:administration & dosage* / Q000737:chemistry; D002417:Cattle; D004317:Doxorubicin / Q000008:administration & dosage* / Q000737:chemistry; D004337:Drug Carriers; D004339:Drug Compounding; D006801:Humans; D007477:Ions / Q000097:blood; D008081:Liposomes; D051379:Mice; D008807:Mice, Inbred BALB C; D000644:Quaternary Ammonium Compounds / Q000097:blood*; D051381:Rats; D012995:Solubility
chemical_list: D000903:Antibiotics, Antineoplastic; D004337:Drug Carriers; D007477:Ions; D008081:Liposomes; D000644:Quaternary Ammonium Compounds; D004317:Doxorubicin