Researchers have developed a drug capsule that could be used to administer oral doses of insulin, which could replace injections for patients with type 2 diabetes, according to a new study.
About the size of a cranberry, the capsule contains a single, small needle made of compressed insulin, which is injected after the capsule reaches the stomach. The study showed that the capsule could administer enough insulin to lower blood sugar to levels comparable to those produced by injections administered through the skin. They also demonstrated that the device can be adapted to administer other protein drugs.
“We are very hopeful that this new type of capsule will one day help diabetic patients and perhaps anyone who requires therapies that can now only be given by injection or infusion,” said Robert Langer, a professor at the Koch Institute for Integrative Research Cancer in Britain.
The tip of the needle is made of almost 100 percent freeze-dried and compressed insulin.
When the capsule is swallowed, the water in the stomach dissolves the sugar disk, releasing the spring and injecting the needle into the wall of the stomach.
The stomach wall has no pain receptors, so patients could not feel the injection prick. To make sure the medication is injected into the stomach wall, researchers designed their system so that, no matter how the capsule falls into the stomach, it can be oriented so that the needle is in contact with the lining of the stomach.
The findings, published in the journal Science, showed that researchers could successfully administer up to 300 micrograms of insulin.
More recently, they have been able to increase the dose to 5 milligrams, which is comparable to the amount that a patient with type 2 diabetes would need to inject.
In addition, no adverse effects were found on the capsule, which is made of biodegradable polymers and stainless steel components.
Importantly, this type of drug administration may be useful for any protein drug that is normally injected, such as immunosuppressants used to treat rheumatoid arthritis or inflammatory bowel disease, and may also work for nucleic acids such as DNA and the RNA, according to the researchers.