Calcium-oligochitosan-pectin microcarrier for colonic drug delivery

Abstract

Pectin-based hydrogel microcarriers have shown promise for drug delivery to the colonic region. Microcarriers must remain stable throughout the upper gastrointestinal tract for effective colonic delivery, an issue that traditional pectin-based microcarriers have faced. The positively-charged natural biopolymer oligochitosan and divalent cation Ca²⁺ were used to dually cross-link pectin-based hydrogel microcarriers to improve carrier stability through simulated gastric and intestinal environments. Microcarriers were characterized with Scanning Electron Microscope and Fourier-Transform Infrared analysis. An optical microscope was used to observe the change of microcarrier size and morphology over time in the simulated gastrointestinal environments. Fluorescently-labeled Dextran was used as a model drug for this system. Calcium-Oligochitosan-Pectin microcarriers exhibited relatively small drug release in the upper gastrointestinal regions and were responsive to the high pH and enzymatic activity of simulated colonic environment (over 94% release after 2 h), suggesting great potential for colonic drug delivery.

Keywords:

• Pectin
• oligochitosan
• microcarrier
• colonic drug delivery
• microencapsulation

Acknowledgments

The authors would like to recognize Dr. Xingkang Huang (University of Wisconsin-Milwaukee) and Lixia Ren (Tianjin University) for their technical assistance.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is supported by the Seed Money Grant from the Rader School of Business and the Faculty Summer Development Grant at the Milwaukee School of Engineering.