Oral administration is unquestionably the most common method of drug delivery; it’s easy to simply swallow a pill. However, peptide and protein drugs cannot be administered this way. One of the major causes why large protein drugs are so difficult to administer orally is that they cannot get past the mucus barrier that borders the digestive tract. This means that insulin or pharmaceutical drugs made out of proteins or nucleic acids must be injected or given in a hospital.
A study published in Science Robotics demonstrates a novel drug capsule devised at MIT that incorporates a robotic cap that rotates and burrows through the mucus barrier as it enters the small intestine, enabling drugs carried by the capsule to enter the intestinal cell lining. The mucus displacement can boost the drug distribution in a localized region, thereby enhancing the assimilation of both small molecule and macromolecule pharmaceuticals. The researchers asserted that they could employ this technique to orally administer insulin and vancomycin (an injectable antibiotic).
The basic concept of developing a protective capsule with a mechanism capable of tunneling through mucus is similar to how tunnel-boring machines bore into earth and rock. When ingested, the coating dissolves within the digestive tract, and the change in pH causes a small motor within the RoboCap capsule to spin. Furthermore, the capsule is also covered with little studs or pegs that, like a toothbrush, sweep mucus away.
The researchers have administered insulin and vancomycin via this capsule in animal studies and found that it delivers 20 to 40 times more medication than a comparable capsule without the tunneling mechanism. Once the drug is released, the capsule travels through the digestive tract. There was no inflammation or discomfort, and the mucus layer recovered within a few hours of being moved by the smart pill. The use of this new capsule to deliver other drugs is yet to be explored, but it could be a game changer for disease treatments.