Oral delivery of insulin using pH-responsive complexation gels.

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Endocrinology

Background:

• Oral insulin delivery faces challenges due to proteolytic degradation in the gastrointestinal tract.
• Existing delivery methods often fail to protect insulin effectively, necessitating frequent injections.
• Developing stable oral insulin formulations is crucial for improving diabetes management.

Purpose of the Study:

• To investigate the efficacy of pH-responsive poly(methacrylic-g-ethylene glycol) hydrogels as oral insulin delivery vehicles.
• To assess the protective capabilities of these hydrogels against proteolytic degradation in the stomach.
• To evaluate the hypoglycemic effect and duration of orally administered insulin encapsulated in these hydrogels.

Main Methods:

• Insulin was loaded into pH-responsive poly(methacrylic-g-ethylene glycol) hydrogels.
• Polymeric microspheres containing insulin were orally administered to healthy and diabetic Wistar rats.
• The behavior of the hydrogels in different gastrointestinal pH environments was observed.
• Blood glucose levels and hypoglycemic effects were monitored over time.

Main Results:

• Hydrogels remained unswollen in the acidic stomach environment, protecting insulin from degradation.
• In the intestine, hydrogels swelled in neutral/basic pH, releasing insulin effectively.
• A strong, dose-dependent hypoglycemic effect was observed within 2 hours in both healthy and diabetic rats.
• The hypoglycemic effects persisted for up to 8 hours post-administration.

Conclusions:

• pH-responsive poly(methacrylic-g-ethylene glycol) hydrogels are effective vehicles for oral insulin delivery.
• These hydrogels successfully protect insulin from degradation and enable controlled release in the intestine.
• The study demonstrates a promising non-invasive approach for insulin delivery with significant therapeutic potential.