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Structured Drug-eluting Bioresorbable Films: Microstructure and Release Profile
Department of Biomedical Engineering, Faculty of Engineering Tel Aviv
University, Tel Aviv 69978, Israel
* To whom correspondence should be addressed.
Bioresorbable drug-eluting films can be used in many biomedical applications.
Examples for such applications include biodegradable medical support devices which
combine mechanical support with drug release and antibiotic-eluting film coatings
for prevention of bacterial infections associated with orthopedic implants or during
gingival healing. In the current study, bioresorbable drug-loaded polymer films are
prepared by solution processing. Two film structures are studied: A polymer film
with large drug crystals located on its surface (A-type) and a polymer film with
small drug particles and crystals distributed within the bulk (B-type). The basic
mode of drug dispersion/location in the film (A or B-type) is found to be
determined mainly by the process of film formation and depends mainly on the solvent
evaporation rate, whereas the drug's hydrophilicity has a minor effect on
this structuring process. Most release profiles from A-type films exhibit a burst
effect of Key Words: bioresorbable films, controlled drug delivery, dexamethasone, gentamicin, metronidazole, cortisone.
First published on July 16, 2008, doi:10.1177/0885328207088261 |
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30% and a second release stage that occurs at an
approximately constant rate and is determined mainly by the polymer weight loss
rate. An extremely high burst release is exhibited only by a very
hydrophilic drug. The matrix (monolithic) nature of the B-type film enables release
profiles that are determined mainly by the host polymer's degradation
profile, with a very low burst effect in most of the studied systems. In addition to
the drug location/dispersion in the film, the host polymer and drug type
also strongly affect the drug's release profile from the film. It has been
demonstrated that appropriate selection of the process parameters and film
components (polymer and drug) can yield film structures with desirable drug release
behaviors. This can lead to the engineering of new bioresorbable
drug-eluting film-based implants for various applications.