Smart Capsule For Insulin

The Moscow chemists have suggested a way to produce insulin in pills instead of injections. They have developed polymeric capsules that would protect insulin from destructive effect of digestive juices. The research has been accomplished with financial support of the Ministry of Industry, Science and Technology of Russia within the framework of international scientific cooperation.

Once insulin appeared, diabetes mellitus is no longer a verdict for the patients. However, to control the sugar level in blood, diabetics have to make injections on a regular basis up to several times a day, which undoubtedly makes their life more difficult. The lack of timely injection may result in fatal outcome. The pills would significantly simplify their life. However, the fact that insulin gets quickly destroyed when it appears in acid medium of the stomach does not exclude but significantly complicates creation of pilled insulin. Researchers of the Chemical Faculty, Lomonosov Moscow State University, have found the way to protect insulin from digestive juices’ destructive effect and to preserve the ability to perform its function.

To introduce insulin in the organism, the Russian chemists suggested that multi-layer polymeric capsules should be used. These polymeric capsules are stable and remain intact in acid medium, and in neutral medium, capsules gradually excrete insulin.

To create such capsules, the researchers used two polymers – positive protamin and negative dextransulphate. They formed layers in series one upon the other according to the plus towards minus principle and made a multi-layer covering around the insulin filling, which makes up to 85 percent of the entire microparticle.

Insulin covered by protective capsule is stable at pH from 1.7 to 5 units, when pH increases higher than 5 units, insulin gets released. Further pH increase up to 8 units results in accelerated protein release rate. Such behavior of particles occurs due to the fact that at pH higher than 5.5 insulin acquires negative charge and its bond with the negatively charged polymer of the first layer – dextransulphate – gets destroyed.

Such pH-dependence of protective polymeric capsules provides fundamental capability to create insulin in pills. In the stomach, where medium is extremely acid, these capsules would protect the insulin molecule and would not allow its destruction. Having gone through the stomach and having reached the small intestine and ileum, where pH reaches 6 to 8 units, capsules will start to excrete insulin intensely. In thin intestines, insulin can penetrate blood. Therefore, the capsule determines by itself where insulin should be retained in closed form and where it should be released.

The polymers used to create capsules belong to natural biodegradable polymers. After utilization they get easily destroyed by enzymes and removed from the organism without causing any harm to health.