Researchers from the Massachusetts Institute of Technology, Brigham and Women’s Hospital and Novo Nordisk have come up with an oral insulin pill that could replace injections for patients with Type 2 diabetes, according to an article in the February 8 issue of the peer-reviewed journal, Science.
The pill is about the size of a blueberry and contains a small needle made of insulin. When it reaches the stomach, it adjusts its orientation to ensure contact with stomach tissue before injecting the insulin.
In tests with rats and pigs, the drug successfully lowered blood sugar to levels similar to those seen with insulin injections, according to researchers.
Previous attempts to develop an oral insulin pill have failed because the gastrointestinal tract is acidic and full of digestive enzymes that can attack and degrade proteins. And the dense cellular wall of the GI tract makes it difficult for large-molecule protein-based drugs to pass through. Past attempts at oral insulin pills have only managed to deliver 1% of the drug into circulation.
“We are really hopeful that this new type of capsule could someday help diabetic patients and perhaps anyone who requires therapies that can now only be given by injection or infusion,” according to Robert Langer, the study’s co-senior author.
For the new capsule, researchers developed a device that has a single microneedle with a tip made of freeze-dried insulin. The injection is controlled by a compressed spring that is restrained by a sugar disc. Water in the stomach can dissolve the disc and serve as the trigger to release the spring and inject the needle into the gastric wall.
To ensure that the injector wouldn’t misfire, they turned to the tortoise and its ability to flip over when it falls onto its back. Using computer modeling, the scientists designed a pill with a similar shape. That’s how the pill reorients itself and is always in the right position.
“What’s important is that we have the needle in contact with the tissue when it is injected,” according to Alex Abramson, another study author. “Also, if a person were to move around or the stomach were to growl, the device would not move from its preferred orientation.”
