MIT and Massachusetts General Hospital (MGH) have devised a novel drug capsule coated with tiny needles that can inject drugs directly into the lining of the stomach after the capsule is swallowed. In animal studies, the team found that the capsule delivered insulin more efficiently than injection under the skin, and there were no harmful side effects as the capsule passed through the digestive system. When the pill reaches the desired location in the digestive tract, the pH-sensitive coating surrounding the capsule dissolves, allowing the drug to be released through the microneedles. This therapeutic-use illustration of the microneedle pill shows the use of hollow needles and solid needles made from sugars or polymers. In both cases, the pill’s needles are initially coated by a pH-responsive coating to aid in ingestion (left). When the pill has reached the desired location in the GI tract, the coating dissolves, revealing the microneedles (middle). In the case of hollow microneedles (top right), the drug reservoir is compressed through peristalsis, releasing the drug through the needles. In the case of solid microneedles (bottom right), the drug is formulated into the microneedles.
