Sick sense

A pill that can analyse the body’s chemistry to calculate and deliver the optimum dose of drugs could help to minimise the side effects of medication taken by sufferers of diseases such as cancer or AIDS.

The Intelligent Pill or iPill, developed by researchers at Canada’s University of Calgary, contains a micropump and sensors.

After the iPill is swallowed, the sensors measure the body’s temperature and pH balance at several locations. If these are above a certain level, the unit responds by pumping out more or less of its drug payload. A modified version able to detect glucose levels could be used to deliver precise doses of insulin to diabetics.

Electrical engineer and iPill inventor Dr. Wael Badawy has created a prototype using silicon oxide sensors. Components are encapsulated in stomach acid-resistant plastic, forming a pill the size of a 5p piece. The electronics cover just 400 sq micrometres – the area of 10 blood cells.

Each pill can store 1ml of drugs in its reservoir. Once the sensors have fed data back to the microprocessor, this applies an electrical force to the pump, which then forces the drug down a channel and out of the pill.

The system is powered by supercapacitators; layers of metal able to store up to four hours’ of power.

According to Badawy, each pill could be sold for under 7p, though the cost of the medicine contained within it would raise the price.

‘Any patient who is prescribed a pill that has to be swallowed should be able to benefit from this device,’ he said. ‘In production, the delivery system will cost between 10 and 20 US cents apiece.’

Over-use of some medicines such as pain relievers causes damage to organs like the kidneys and liver. The iPill is claimed to prevent this by tailoring the dose delivered to the body’s needs.

It can also be programmed to release drugs at regular intervals, making it particularly useful in the treatment of illnesses such as cancer, where drug cocktails must be taken regularly.

Once the device is spent, it passes through the body within one to three days, along with other solid waste.

The prototype has so far proved reliable in laboratory tests, and should progress to animal trials within the next year. Badawy anticipates that it should be approved for human use within five years.

He is now developing a power source that can be integrated within the iPill to last for between 12 and 24 hours.