title: Preparation, characterization and in vitro release properties of morphine-loaded PLLA-PEG-PLLA microparticles via solution enhanced dispersion by supercritical fluids.
abstract: Morphine-loaded poly(L-lactide)-poly(ethylene glycol)-poly(L-lactide) (PLLA-PEG-PLLA) microparticles were prepared using solution enhanced dispersion by supercritical CO2 (SEDS). The effects of process variables on the morphology, particles size, drug loading (DL), encapsulation efficiency and release properties of the microparticles were investigated. All particles showed spherical or ellipsoidal shape with the mean diameter of 2.04-5.73 μm. The highest DL of 17.92 % was obtained when the dosage ratio of morphine to PLLA-PEG-PLLA reached 1:5, and the encapsulation efficiency can be as high as 87.31 % under appropriate conditions. Morphine-loaded PLLA-PEG-PLLA microparticles displayed short-term release with burst release followed by sustained release within days or long-term release lasted for weeks. The degradation test of the particles showed that the degradation rate of PLLA-PEG-PLLA microparticles was faster than that of PLLA microparticles. The results collectively suggest that PLLA-PEG-PLLA can be a promising candidate polymer for the controlled release system.
authors.affiliation: College of Materials Science and Engineering, Sichuan University, No.24, South 1st Section, 1st Ring Road, Chengdu, 610065, Sichuan, People's Republic of China.
authors.forename: Fu
authors.initials: F
authors.lastname: Chen
authors.forename: Guangfu
authors.initials: G
authors.lastname: Yin
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Liao
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Zhongbing
authors.initials: Z
authors.lastname: Huang
authors.forename: Jianwen
authors.initials: J
authors.lastname: Gu
authors.forename: Yadong
authors.initials: Y
authors.lastname: Yao
authors.forename: Xianchun
authors.initials: X
authors.lastname: Chen
authors.forename: Hu
authors.initials: H
authors.lastname: Gao
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000493:pharmacokinetics; D025924:Chromatography, Supercritical Fluid; D003692:Delayed-Action Preparations; D004058:Diffusion; D004337:Drug Carriers / Q000138:chemical synthesis* / Q000737:chemistry* / Q000493:pharmacokinetics; D004339:Drug Compounding / Q000379:methods; D007773:Lactates / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D009020:Morphine / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D009994:Osmolar Concentration; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry*; D011312:Pressure; D012996:Solutions
chemical_list: D000701:Analgesics, Opioid; D003692:Delayed-Action Preparations; D004337:Drug Carriers; D007773:Lactates; D012996:Solutions; C088513:poly(lactic acid-ethylene glycol); D011092:Polyethylene Glycols; D009020:Morphine