Insulin can be protected inside a chemical polymer coating, bringing the possibility of an insulin capsule even closer, say researchers.
The novel polymer coating ensures that an oral insulin capsule is not broken down by enzymes and remains intact once it reaches the blood stream.
"Our research is taking us a significant step forward towards this important goal and offering hope to people who are living with diabetes," said Dr Colin Thompson at the University's School of Pharmacy.
However, he adds that the capsule needs to be tested in order to determine its suitability as an insulin delivery system, and the creation of an insulin pill is still some years away.
Libby Dowling, care advisor at Diabetes UK, said: "Oral insulin could make a big difference to the lives of people with diabetes.
"Children, elderly people and those with a phobia of needles would benefit particularly if and when insulin capsules become and safe and effective treatment for the condition.
"Hundreds of thousands of people have to inject themselves several times a day to control their diabetes. This can cause a great deal of stress to some people and be difficult to come to terms with.
"Although more research is needed, Diabetes UK would very much like to see insulin capsules one day become a reality."