title: Self-assembled drug delivery systems: Part 3. In vitro/in vivo studies of the self-assembled nanoparticulates of cholesteryl acyl didanosine.
abstract: Self-assembled drug delivery systems (SADDS) are defined as the self-assemblies of amphiphilic prodrugs, integrating prodrugs, molecular self-assembly and nanotechnology for drug targeting and controlled release. Cholesteryl-succinyl didanosine (CSD) and cholesteryl-adipoyl didanosine (CAD) nanoparticulate systems in water were previously prepared and optimized. In this paper, the in vitro and in vivo behavior of them was investigated. Precipitation occurred when they were mixed with acid solutions due to rapid production of hypoxanthine and subsequent disruption of supramolecular structures. They showed pH-dependent degradation and kept relatively stable in the neutral pH range. CSD is more stable than CAD due to the shorter spacer and poloxamer protection. CSD showed different degradation rates in various plasma with the descending order of rat, mouse, rabbit, dog and human. The half-life (t(1/2)) of CSD is 9 days in rat plasma, and 5.9 days in rat liver homogenates. CAD has a faster degradation than CSD though the t(1/2) in rat liver homogenates is long to 23 h. CSD nanoparticulates showed no significant anti-HIV effect in MT4 cell model because of very slow degradation. CSD nanoparticulates showed the distribution t(1/2) of 7.6 min after bolus intravenous (i.v.) administration to rats, and the site-specific distribution in liver, lung and spleen with the high t(1/2) of 10 days in liver. The factors affecting achievement of successful SADDS are discussed.
authors.affiliation: Department of Pharmaceutical Chemistry, Beijing Institute of Radiation Medicine, Beijing 100850, PR China. jin_yiguang@yahoo.com.cn
authors.forename: Yiguang
authors.initials: Y
authors.lastname: Jin
authors.forename: Ping
authors.initials: P
authors.lastname: Ai
authors.forename: Rui
authors.initials: R
authors.lastname: Xin
authors.forename: Ying
authors.initials: Y
authors.lastname: Tian
authors.forename: Junxing
authors.initials: J
authors.lastname: Dong
authors.forename: Dawei
authors.initials: D
authors.lastname: Chen
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D002460:Cell Line; D002784:Cholesterol / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics; D016049:Didanosine / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000737:chemistry / Q000493:pharmacokinetics; D004285:Dogs; D016503:Drug Delivery Systems; D004355:Drug Stability; D006207:Half-Life; D006801:Humans; D007275:Injections, Intravenous; D051379:Mice; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology; D010316:Particle Size; D011355:Prodrugs / Q000737:chemistry* / Q000493:pharmacokinetics; D011817:Rabbits; D051381:Rats; D012995:Solubility; D014018:Tissue Distribution
chemical_list: D000998:Antiviral Agents; D011355:Prodrugs; D002784:Cholesterol; D016049:Didanosine