Efficient drug release by absorbable foam
Aachen, in January 2013. The Institute of Plastics Processing (IKV) at RWTH Aachen
University is investigating, together with partner institutes, the controlled release of drugs for
the treatment of common diseases of the urinary bladder as e.g. the overactive bladder. The
drug delivery system (DDS) consists of a drug-loaded polymer matrix, so called
microspheres, which are embedded in a foamed absorbable carrier system. Within this joint
project, it is IKV's task to develop the foamed carrier system. Other project partners are Dr.
Pfleger GmbH, Hemoteq AG, DWI at RWTH Aachen, and the department of Urology of the
University Hospital Aachen (UKA).
In this novel approach of treatment the drug delivery system (DDS) is directly placed into the
urinary bladder. The drug release and the excretion of the system are controlled by the
degradation of the carrier system. Thus, the active agent has a locally lasting effect in the
bladder and won't affect the whole body compared with the intake of tablets. Also a regular
catheterisation in short time intervals, often several times a day, is no longer required.
The carrier system is manufactured at IKV in the CESP process (Controlled Expansion of
Saturated Polymers). The technology of the CESP process enables the possibility of
processing temperature-sensitive materials, like the used poly (D,L-lactide-co-glycolide)-coPEG. The material can be processed in a CO2 atmosphere at high pressure (approx. 50 bar)
at low temperatures of approx. 50 °C. By an extension of the CESP process, a powdery
polymer microsphere mixture can be foamed specific via a pressure controlled, continuous
variable discharge. The adjustment of the degradation of the carrier system to medically
necessary periods is possible by the termination of the foam structure. For reproducible
manufacturing of the carrier system in the range of micrograms a dosing unit and adapted
cavities are integrated into the process chain.
This extension of the CESP process allows more applications in the scope of absorbable,
drug-eluting implants. By means of the reproducible dosing of the materials and the
optimised controlling of the process, porous osteosynthesis plates or stents are as well
The participating institutes extend their thanks to the Bundesministerium für Bildung und
Forschung (BMBF) for supporting this research project (No. 13 N 11306).
INSTITUT FÜR KUNSTSTOFFVERARBEITUNG · LEITER: PROF. DR.-ING. CHRISTIAN HOPMANN
RWTH Aachen · 52056 Aachen · Germany · Telefon +49 (0) 241 80-93806 · Fax +49 (0) 241 80-92262 · www.ikv-aachen.de
IKV, the Institute of Plastics Processing at RWTH Aachen University, is Europe-wide the biggest research and
education institute engaged in the field of plastics processing enjoying outstanding reputation. More than 300 staff
are employed in finding solutions to problems connected with processing, materials technology and part design in
the plastics and rubber industries. IKV's close contacts with industry and science, together with its outstanding
facilities, enable cutting-edge research in plastics technology and ensure that students benefit from a
comprehensive, practically oriented course of study. Plastics engineering graduates from IKV are thus soughtafter experts in industry. In organisational terms, IKV is divided up into the four specialist departments of Injection
Moulding and PU Technology, Extrusion and Further Processing, Part Design and Materials Technology, and
Composites. The Institute also takes in the Centre for Analysis and Testing of Plastics, and the Training and
Further Education department. IKV is run by an Association of Sponsors, which currently has a membership of
more than 230 plastics companies from all over the world. Univ.-Prof. Dr.-Ing. Christian Hopmann is Head of the
Institute and Managing Director of the Association of Sponsors. He also holds the Chair of Plastics Processing at
the Faculty of Mechanical Engineering at RWTH Aachen University.