title: Fabrication and in vitro drug release of drug-loaded star oligo/poly(DL-lactide) microspheres made by novel ultrasonic-dispersion method.
abstract: Cholic acid functionalized star oligo/poly(DL-lactide)s with different molecular weights were synthesized through the ring-opening polymerization of DL-lactide initiated by cholic acid. On the basis of the specific physicochemical properties of the star oligo/poly(DL-lactide)s, submicron sized drug-delivery systems were fabricated using a very convenient "ultrasonic dispersion method," which did not involve toxic organic solvents. The drug-loaded microspheres had a regular spherical shape with a narrow size distribution. The effects of ultrasonic power and the molecular weight of polymers on the microsphere fabrication were investigated. The in vitro drug release was studied. The release profiles were fitted by the classical empirical exponential expression. The fitting result indicated that the drug release was controlled by combined degradation and diffusion mechanism.
authors.affiliation: Key Laboratory of Biomedical Polymers of Ministry of Education, Department of Chemistry, Wuhan University, Wuhan 430072, People's Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zou
authors.forename: Song-Lin
authors.initials: SL
authors.lastname: Li
authors.forename: Si-Xue
authors.initials: SX
authors.lastname: Cheng
authors.forename: Xian-Zheng
authors.initials: XZ
authors.lastname: Zhang
authors.forename: Ren-Xi
authors.initials: RX
authors.lastname: Zhuo
mesh_terms: D019826:Cholic Acid / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008863:Microspheres; D011091:Polyesters / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D003692:Delayed-Action Preparations; D011091:Polyesters; C033616:poly(lactide); D019826:Cholic Acid