Insulin patch-containing capsule could lead to oral diabetes treatments

An intestinal patch device containing insulin that can be swallowed as a capsule can effectively control blood glucose levels, a new study finds.
Oral insulin is currently being investigated as a diabetes treatment, but the problem with taking insulin through the mouth is that digestive enzymes in the gastrointestinal tract break down the insulin so that it is no longer active.
Researchers at the University of California Santa Barbara have produced a patch made from mucoadhesive polymers. These polymers have insulin loaded inside them, and can be carried through the body inside a protective shell.
The patch is also treated with an intestinal permeation enhancer, to improve drug delivery, and placed inside a capsule with an enteric coating. This protects the insulin from the acidity of the stomach. Once the pill has been swallowed, it is designed to dissolve and release the patches of insulin. These patches can then stick to the intestinal wall for a more effective delivery of insulin.
The researchers tested the intestinal patch on diabetic rat models. The mucoadhesive strength of the patches was assessed by removing them from the intestine after 30 minutes, while the release of the drugs was also measured.
The rats were fasted overnight and fed the capsules orally. Their blood glucose levels were then calculated at different time intervals up to eight hours.
The patches released 100 per cent of the insulin and permeation enhancer content within five hours, demonstrating excellent mucoadhesive strength. Insulin patches that contained 10 per cent permeation enhancer were found to be most effective, and caused blood glucose levels to drop significantly compared to a control group who received no treatment.
Samir Mitragotri, PhD, and Amrita Banerjee, University of California Santa Barbara, said: “We’ve created a technology with several innovative features. Our mucoadhesive devices fit inside of a small capsule and then deliver the drug in the intestine in a very effective manner. There are many possible benefits and advantages of an oral delivery for insulin.”
The researchers next plan to continue rat studies to determine how intestinal patches can achieve faster or extended release of insulin.
These findings were presented on October 27 at the 2015 American Association of Pharmaceutical Scientists (AAPS) Annual Meeting and Exposition.