pH-triggered drug release from biodegradable microwells for oral drug delivery

Biomed Microdevices. 2015;17(3):9958. doi: 10.1007/s10544-015-9958-5.

Abstract

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorbable Implants*
  • Administration, Oral
  • Capsules
  • Diffusion
  • Drug Implants / administration & dosage
  • Drug Implants / chemical synthesis*
  • Furosemide / administration & dosage
  • Furosemide / chemistry*
  • Gastric Juice / chemistry*
  • Humans
  • Hydrogen-Ion Concentration*
  • Lactic Acid / chemistry*
  • Materials Testing
  • Polyesters
  • Polymers / chemistry*

Substances

  • Capsules
  • Drug Implants
  • Polyesters
  • Polymers
  • Lactic Acid
  • poly(lactide)
  • Furosemide