Insulin and other protein-based medications cannot be made as easy-to-take tablets because they cannot withstand passage through the gastrointestinal tract. Other drugs can be injected into the body by dissolving and digesting, like regular food, but insulin must be delivered directly into the bloodstream. American scientists have made a major breakthrough in solving this problem by creating a drug capsule with microneedles.
In 2014, a technique for safe injections through the mucous membrane of the small intestine was developed, in 2016 the design of a folding system with needles appeared, and in 2018 a prototype of a capsule was shown that injected insulin into the blood through the walls of the stomach. Now scientists have presented a new version of the capsule that will withstand the journey through the aggressive environment of the stomach to the very small intestine.
The small intestine is interesting in that its membranes do not have nerve endings, and therefore the injections are absolutely painless here. This made it possible to carry out experiments on pigs with needle lengths up to 30 mm, but for humans, a limit of 1 mm was set. This is enough to pierce the mucous membrane and inject the medicine, but the size of the device itself is significantly reduced. And this is important so as not to create a risk of intestinal blockage.
Stomach acid from an obstacle turned into a main assistant when scientists selected the necessary materials for the capsule. Its outer shell will hold out exactly until it enters the small intestine, where it will fall apart, and the microsprings will open a “star” made of microneedle plates. It will also dissolve and by the end of the injection will fall apart into separate small pieces that will come out naturally. The first successes inspire scientists - they are ready to develop microcapsules for the delivery of any kind of drugs.