Researchers have developed tiny ‘submarines’ that speed through the stomach using gastric acid for fuel. The proton-driven micromotors have a pH-sensitive polymer coating that can be loaded with drugs and released in the stomach.
Gastric acid can be destructive for orally-administered, pH-sensitive pharmaceuticals, including antibiotics. Although some coatings can protect substances from gastric acid, they can also prevent drugs from being activated in the stomach. Proton pump inhibitors, which block production of acid, can cause adverse side effects in patients if used for a long period of time.