New type of gel helps the medicine go down

Swallowing tablets can be a challenge for most children and some adults, but scientists have come to the rescue with a new drug-delivering oleogel that can make it easier to consume a variety of medicines.

According to a new study, the gels are made from plant-based oils and can be prepared in a variety of textures – from a thickened drink to a gel with yogurt-like consistency. This could help adults who have difficulty swallowing pills, such as older people or those who have suffered a stroke.

The gels have also been designed to remain stable at 40°C for two weeks, and even up to 60°C for one week. This could make them especially helpful for children in developing nations, where the gels might be transported in vehicles without refrigeration. 

“Given the simplicity of the system and its low cost, it could have a tremendous impact on making it easier for patients to take medications,” says senior author Giovanni Traverso, assistant professor of mechanical engineering at Massachusetts Institute of Technology (MIT) and a gastroenterologist at Brigham and Women’s Hospital, US.

Existing strategies for people unable to swallow pills have relied on dissolving drugs in water, but this requires a water-soluble medicine, as well as access to clean water and refrigeration. It can also be difficult to achieve the right dosage for children if the pills used are meant for adults.

To avoid these issues, the interdisciplinary research team focused on the potential of oil-based gels, also known as oleogels, for drug delivery.

The researchers explored several different types of plant-derived oils, including sesame, cottonseed and flaxseed oil. By combining these oils with edible gelling ingredients – such as beeswax and rice bran wax – they found they could control the texture depending on the type of oil and gelling agent, and their concentrations.

To identify the most palatable oleogels, the researchers worked with a consulting firm specialising in consumer sensory experiences to narrow down the oleogels to those made from oils with a neutral or slightly nutty flavour.

“That approach gave us the capacity to deliver very hydrophobic drugs that cannot be delivered through water-based systems,” says lead author Ameya Kirtane, former MIT postdoctoral researcher and current instructor in medicine at Brigham and Women’s Hospital. “It also allowed us to make these formulations with a really wide range of textures.”

They then tested delivering three oil-soluble (hydrophobic) drugs from the World Health Organization’s (WHO) list of essential medicines for children: praziquantel, used to treat parasitic infections; lumefantrine, used to treat malaria; and azithromycin, used to treat bacterial infections.

The tests showed that in pigs the oleogels were able to deliver doses of these medicines equal to or greater than the amounts absorbed from tablets, and that a water-soluble antibiotic (moxifloxacin hydrochloride) could also be successfully delivered.

“Based on that list, infectious diseases really stood out in terms of what a country needs to protect its children,” Kirtane says. “A lot of the work that we did in this study was focused on infectious-disease medications, but from a formulation standpoint, it doesn’t matter what drug we put into these systems.”

A phase I clinical trial of the oleogel formulation of azithromycin should be underway within the next few months.

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