Herstellung von Mikropartikeln aus einem abbaubaren Multiblockcopolymer zur Freisetzung von proteinischen Wirkstoffen
type: CreativeWork
description: Based on the semi-crystalline and biodegradable multiblock-copolymer of poly(p-dioxanon) and poly(?-caprolacton) matrix drug delivery systems (films and particles) are developed for proteins. Protein-loaded microparticles are produced in cylindrical reactors by means of the double emulsification solvent evaporation technique. The loading efficiency of the particles (0,32 - 1,2 wt.-% lysozyme) depends on the experimental parameters (volume of second emulsifier, ethanol as phase mediator in the second emulsifier). Attempts to produce particles by means of the original spray drying method were unsuccesful due to the semi-crystalline property of the polymer. During spraying of the polymer solution, the nozzle is clogged and in the drying chamber, some sticky fibers are formed as well as ruptured spherical particles with a diameter of 10 to 100 µm. SEM shows that a wide size distribution of particles exist. Particles formed by the double emulsification solvent evaporation technique are spherical with a diameter of 0,1 to 2000 µm and a broad size distribution. In most experiments the larger particles (170-1000 µm) represent 80-95% of the total volume. The material properties are examined by analysis of the loaded films. A loading of up to 10 wt.-% protein does not influence the thermal or shape-memory properties of the material. Young's moduli are cut in half (49 MPa) and the buffer or solvent uptake is doubled. There is no difference for the elongation at break for the 5, 10 or 20 wt.-% lysozyme loaded polymer. The strain fixity rate in cyclic thermomechanical tensile tests is in the range of 92% for all polymeric materials, pure or loaded (10 or 20 wt.-% lysozyme). For all samples the strain recovery rate of the first cycle is around 80% and achieves 99% in the following cycles and the transition temperature of the shape memory process is around 31°C. For all samples (0, 5, 10 or 20wt.-% lysozyme) the value of the transition coeffizient ? is (0,26 ( 0,01) 10-1K-1. If th…
abstract: Based on the semi-crystalline and biodegradable multiblock-copolymer of poly(p-dioxanon) and poly(?-caprolacton) matrix drug delivery systems (films and particles) are developed for proteins. Protein-loaded microparticles are produced in cylindrical reactors by means of the double emulsification solvent evaporation technique. The loading efficiency of the particles (0,32 - 1,2 wt.-% lysozyme) depends on the experimental parameters (volume of second emulsifier, ethanol as phase mediator in the second emulsifier). Attempts to produce particles by means of the original spray drying method were unsuccesful due to the semi-crystalline property of the polymer. During spraying of the polymer solution, the nozzle is clogged and in the drying chamber, some sticky fibers are formed as well as ruptured spherical particles with a diameter of 10 to 100 µm. SEM shows that a wide size distribution of particles exist. Particles formed by the double emulsification solvent evaporation technique are spherical with a diameter of 0,1 to 2000 µm and a broad size distribution. In most experiments the larger particles (170-1000 µm) represent 80-95% of the total volume. The material properties are examined by analysis of the loaded films. A loading of up to 10 wt.-% protein does not influence the thermal or shape-memory properties of the material. Young's moduli are cut in half (49 MPa) and the buffer or solvent uptake is doubled. There is no difference for the elongation at break for the 5, 10 or 20 wt.-% lysozyme loaded polymer. The strain fixity rate in cyclic thermomechanical tensile tests is in the range of 92% for all polymeric materials, pure or loaded (10 or 20 wt.-% lysozyme). For all samples the strain recovery rate of the first cycle is around 80% and achieves 99% in the following cycles and the transition temperature of the shape memory process is around 31°C. For all samples (0, 5, 10 or 20wt.-% lysozyme) the value of the transition coeffizient ? is (0,26 ( 0,01) 10-1K-1. If th…
author: Spiegelberg, Susanne
language: ger
keywords: info:eu-repo/classification/ddc/540, Chemie, Multiblockcopolymer, Shape-Memory, Hydrolyse, Mikropartikel, Sprühtrocknung, W/O/W, Freisetzung, Lysozym
date published: 2004
date modified: 2026-07-30T19:43:19Z
provider: RWTH Aachen University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Publikationsserver der RWTH Aachen University