Background: As society has developed and living standards have improved, diabetes has become a severe
public health issue. Insulin plays a crucial role in managing hyperglycemia caused by type I diabetes and particular
type II diabetes. Many researchers are seeking alternative, more acceptable methods of insulin delivery, such as oral
insulin. An oral formulation has become a new goal for insulin delivery in recent years.
Methods: The PubMed and CNKI databases were searched for “oral insulin, ” “drug delivery systems, ” and “pharmacokinetics,
” and 85 relevant articles were selected from the results as material for this review. These papers were
authoritative and had a higher number of citations.
Results: Oral insulin would be highly advantageous but is poorly absorbed. The main reason for low absorptivity is
the hydrolysis of insulin by enzymes in the gastrointestinal tract. Lack of active transport vectors that pass through
the intestinal epithelium is also a non-negligible problem. Additional issues need to be considered to facilitate appropriate
research, such as long-term efficacy and safety, clinical data, and toxicological characteristics.
Conclusion: This review summarized recent advances in oral insulin and the pharmacokinetic profile of the suitable
delivery system, providing valuable reference material for future research.