title: Amphiphilic dextran-graft-poly(epsilon-caprolactone) films for the controlled release of paclitaxel.
abstract: Amphiphilic graft copolymers with dextrans as the main chains and poly(epsilon-caprolactone) as the side chains were synthesized by solution polymerization in dimethyl sulfoxide using stannous 2-ethylhexanoate as a catalyst. The copolymers were characterized with nuclear magnetic resonance spectroscopy and gel permeation chromatography. Paclitaxel loaded copolymer films were prepared using a solution cast method. In vitro release rates were influenced by both the initial paclitaxel loading and the morphology of the films. The films with paclitaxel loadings up to 10% (w/w) showed a single-phase morphology when dry. However, paclitaxel crystallization occurred in the films with high loadings (5 and 10%) upon incubation in phosphate buffered saline at 37 degrees C. The crystals had a spherulitic structure and were found to be paclitaxel dihydrate based on X-ray diffraction analysis. The formation of paclitaxel dihydrate in the films produced a marked effect on the in vitro release rates.
authors.affiliation: Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, BC, Canada V6T 1Z3.
authors.forename: Ruiwen
authors.initials: R
authors.lastname: Shi
authors.forename: Helen M
authors.initials: HM
authors.lastname: Burt
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage / Q000737:chemistry*; D002850:Chromatography, Gel; D003460:Crystallization; D003692:Delayed-Action Preparations; D003911:Dextrans / Q000138:chemical synthesis / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D017239:Paclitaxel / Q000008:administration & dosage / Q000737:chemistry*; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers; D014961:X-Ray Diffraction
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D003692:Delayed-Action Preparations; D003911:Dextrans; D011091:Polyesters; D011108:Polymers; C016240:polycaprolactone; D017239:Paclitaxel