Daily jabs of insulin are a painful reality for many with diabetes. That may change if researchers who have successfully tested oral insulin in rats are able to replicate those results in humans.
Nearly 350m people worldwide suffer from diabetes and that number is predicted to grow to more than 500m by 2030. While the more common form, type-2 diabetes, does not always need insulin treatment, nearly quarter of all diabetes patients depend on insulin jabs. Oral insulin’s estimated annual sales could be somewhere between $8 billion and $17 billion.
The benefits of an insulin pill are more than just ease of taking the drug. The pill will mean that patients can start taking insulin earlier in the development of the disease, which could reduce some of the secondary complications, which can include blindness and impaired healing that leads to amputations.
The idea of oral insulin has been around since the 1930s, but the difficulties of making it seemed too big to overcome. First, insulin is a protein – when it comes in contact with stomach enzymes, it is quickly destroyed. Second, if insulin can pass through the stomach safely, it is too big a molecule (about 30 times the size of aspirin) to be absorbed into the bloodstream, where it needs to be in order to regulate blood-sugar levels.
Sanyog Jain at India’s National Institute of Pharmaceutical Education and Research and his colleagues have been working on delivering insulin in the oral form for many years. Their first fully-successful attempt came in 2012, when they developed a formulation that successfully controlled blood-sugar level in rats. But the materials used were too expensive to consider commercialising the technology.
Now, in a paper published in the journal Biomacromolecules, they have found a cheaper and more reliable way of delivering insulin. They overcome the two main hurdles by, first, packing insulin in tiny sacs made of lipids (fats), and, second, attaching to it folic acid (vitamin B9) to help improve its absorption into the bloodstream.