Microwells fabricated from poly-L-lactic acid (PLLA) were evaluated for their application as an oral drug delivery system using the amorphous sodium salt of furosemide (ASSF) as a model drug. Hot embossing of PLLA resulted in fabrication of microwells with an inner diameter of 240 μm and a height of 100 μm. The microwells were filled with ASSF using a modified screen printing technique, followed by coating of the microwell cavities with a gastro-resistant lid of Eudragit® L100. The release behavior of ASSF from the coated microwells was investigated using a μ-Diss profiler and a UV imaging system, and under conditions simulating the changing environment of the gastrointestinal tract. Biorelevant gastric medium (pH 1.6) was employed, after which a change to biorelevant intestinal release medium (pH 6.5) was carried out. Both μ-Diss profiler and UV imaging release experiments showed that sealing of microwell cavities with an Eudragit® layer prevented drug release in biorelevant gastric medium. An immediate release of the ASSF from coated microwells was observed in the intestinal medium. This pH-triggered release behavior demonstrates the future potential of PLLA microwells as a site-specific oral drug delivery system.
Bibliographical noteFunding Information:
The authors would like to acknowledge the Villum Kann Rasmussen Foundation and the Danish Research Council for Technology and Production (FTP), Project DFF - 4004-00120B for financial support. Moreover, the NAnoMEChanical sensors and actuators, fundamentals and new directions (NAMEC) – a VKR Centre of Excellence is acknowledged.
© 2015, Springer Science+Business Media New York.
- Biodegradable polymer
- Micro delivery systems
- Oral drug delivery
- UV imaging
- μ-Diss profiler
ASJC Scopus subject areas
- Biomedical Engineering
- Molecular Biology