Oral insulin delivery systems using chitosan-based formulation: a review.

Area of Science:

• Biomaterials Science
• Pharmaceutical Sciences
• Drug Delivery Systems

Background:

• Oral insulin delivery (OID) faces significant hurdles including enzymatic proteolysis, gastric degradation, and poor absorption.
• Chitosan-based insulin formulations are being explored to overcome these natural barriers.

Purpose of the Study:

• To review and evaluate techniques for oral insulin formulations.
• To assess the performance of existing OID formulations.
• To identify future directions for OID research.

Main Methods:

• Systematic review of 86 articles on oral insulin delivery.
• Analysis of formulation techniques, primarily poly-electrolytic complexation and chemical modification.
• Evaluation of in-vitro performance using a '30x70 performance window'.

Main Results:

• Most reviewed oral insulin formulations effectively addressed gastric and enzymatic barriers.
• Formulations showed limitations in overcoming the absorption barrier of the gastrointestinal tract.
• In-vitro results indicate effectiveness, but in-vivo performance requires improvement.

Conclusions:

• Significant research efforts are focused on overcoming gastrointestinal barriers for OID.
• Current OID formulations demonstrate better performance in experimental settings than in in-vivo studies.
• Enhancing in-vivo insulin absorption through the gut is crucial for realizing practical oral insulin delivery.