title: Synthesis and characterization of microparticles made of carboxymethyloxysuccinic-acid-modified PLA-PEG co-polymer.
abstract: A novel tri-block co-polymer, HO2C-PLA-PEG-PLA-CO2H (co-polymer II), with polybasic carboxylic acids as the end-groups was synthesized and characterized by IR and 1H-NMR. Based on the successful synthesis of co-polymer II, water-soluble sodium salicylate and oil-soluble tetrandrine, used as model drugs, were loaded in the co-polymer microparticles prepared through a modified multiple emulsion method. The encapsulation efficiency and drug-releasing behaviour were also investigated. It is found that the microparticles of about 10 microm in size are porous and can be produced from co-polymer II in better encapsulation efficiency (up to 86.65% and 55.94%) compared to those made from PLA/PEG/PLA (co-polymer I) (77.50% and 44.01%). The drug-release behaviour of co-polymer II exhibits an extended continuous release behaviour and the initial burst was reduced obviously. The results show that such functionalised PLA/PEG/PLA carrier provides higher drug encapsulation efficiency and better profiles.
authors.affiliation: Research Institute of Polymeric Materials, Tianjin University, Tianjin 300072, PR China.
authors.forename: Haiyue
authors.initials: H
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Chang
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.forename: Peng
authors.initials: P
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Kang De
authors.initials: KD
authors.lastname: Yao
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.forename: Fanglian
authors.initials: F
authors.lastname: Yao
mesh_terms: D000470:Alkaloids / Q000737:chemistry / Q000493:pharmacokinetics; D044182:Benzylisoquinolines / Q000737:chemistry / Q000493:pharmacokinetics; D003692:Delayed-Action Preparations / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000138:chemical synthesis / Q000737:chemistry*; D007773:Lactates / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry; D012980:Sodium Salicylate / Q000737:chemistry / Q000493:pharmacokinetics; D013055:Spectrophotometry, Infrared; D013386:Succinates / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000470:Alkaloids; D044182:Benzylisoquinolines; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D007773:Lactates; D011108:Polymers; D013386:Succinates; C088513:poly(lactic acid-ethylene glycol); C009438:tetrandrine; D011092:Polyethylene Glycols; D012980:Sodium Salicylate