A team from Nanyang Technological University, Singapore (NTU Singapore) and the National University Health System (NUHS) has developed a self-inflating weight management capsule – Endopil – that could be used to treat obese patients.

The prototype capsule contains a balloon that can be self-inflated with a handheld magnet once it is in the stomach, thus inducing a sense of fullness. Its magnetically-activated inflation mechanism causes a reaction between a harmless acid and a salt stored in the capsule, which produces carbon dioxide to fill up the balloon.

The concept behind the Endopil is for it to be ingested orally, though trials using this route for administration have not yet begun.

Designed by a team led by Professor Louis Phee, NTU Dean of Engineering, and Professor Lawrence Ho, a clinician-innovator at NUHS, such an orally administered self-inflating weight loss capsule could represent a non-invasive alternative to tackle the growing global obesity epidemic.

Today, moderately obese patients and those who are too ill to undergo surgery can opt for the intragastric balloon, an established weight loss intervention that has to be inserted into the stomach via endoscopy under sedation. It is removed six months later via the same procedure.

As a result, not all patients are open to this option as the balloon has to be inserted into the stomach via endoscopy and under sedation. It is also common for patients who opt for the intragastric balloon to experience nausea and vomiting, with up to 20 per cent requiring early balloon removal due to intolerance.

The stomach may also get used to the prolonged placement of the balloon within, causing the balloon to be less effective for weight loss.

The novel made-in-Singapore weight loss capsule, designed to be taken with a glass of water, could overcome these limitations. The viability of Endopil was first tested in a pre-clinical study, in which a larger prototype was inserted into a pig. The findings, published in a supplement of scientific journal Gastroenterology, showed that the pig with the inflated capsule in its stomach lost 1.5kg a week later, while a control group of five pigs gained weight.

Last year, the team trialled their capsule on a healthy patient volunteer in Singapore, with the capsule inserted into her stomach through an endoscope. The balloon was successfully inflated within her stomach, with no discomfort or injury from the inflation.

Currently, the capsule has to be deflated magnetically. The team is now working on a natural decompression mechanism for the capsule, as well as reducing its size.

Professor Louis Phee, who is also the Tan Chin Tuan Centennial Professor in Mechanical Engineering at NTU, said, “EndoPil’s main advantage is its simplicity of administration. All you would need is a glass of water to help it go down and a magnet to activate it. We are now trying to reduce the size of the prototype, and improve it with a natural decompression mechanism. We anticipate that such features will help the capsule gain widespread acceptance and benefit patients with obesity and metabolic diseases.”

Professor Lawrence Ho from the NUS Yong Loo Lin School of Medicine, who is also a Senior Consultant with the Division of Gastroenterology and Hepatology at the National University Hospital, said, “EndoPil’s compact size and simple activation using an external hand-held magnet could pave the way for an alternative that could be administered by doctors even within the outpatient, and primary care setting. This could translate to no hospital stay, and cost saving to the patients and health system.”