Pharmacists use various mechanisms to control the release of drugs from a pill. For example, the pill may have a coating that is designed to be dissolved in a particular part of the digestive tract or after a certain amount of time.
But this does not always work since the rate of passage through the body can vary, and some individuals have higher levels of digestive enzymes than others. So the electronics company Philips has come up with a remote-controlled pill with a cavity for carrying a drug which can be opened by a remote signal.
The passage of the pill can be followed by MRI or ultrasound and the drug dispensed with an electronic trigger at the appropriate location.
The drug can also be released according to other external factors. For example, if atmospheric pollen reaches a certain level or the patient's blood pressure hits a predetermined number.
Philips hopes the pills can be made cheaply enough to be disposable, so they need not be collected and recycled after use.