New Delivery Method Could Release Drugs for Up to 2 Weeks

Researchers recently created a novel drug delivery method that allows for the continuous release of a drug for up to 2 weeks after the capsule is swallowed.

This method could replace the traditional method of taking daily medication, and could potentially improve medication adherence, whichhas become an obstacle in treating many diseases.

In a study published by Science Translational Medicine, researchers used the method to deliver ivermectin, which is an antiparasitic drug that is used to treat lice, scabies, and other parasites. The researchers believe that this drug could potentially be used to eliminate malaria and other diseases.

“Until now, oral drugs would almost never last for more than a day,” said senior author Robert Langer, ScD. “This really opens the door to ultra-long-lasting oral systems, which could have an effect on all kinds of diseases, such as Alzheimer’s or mental health disorders. There are a lot of exciting things this could someday enable.”

The delivery method involves a star-shaped device that can be folded inward and encased in a capsule that delivers the full amount of the drug over a period of time, according to the study.

Oral medications only work for a certain amount of time, since they pass through the body and are exposed to the stomach and intestines, which are considered harsh environments. The researchers initially focused on malaria and ivermectin, since the drug can kill mosquitos who bite an individual taking it.

A long-acting delivery method of ivermectin, plus the antimalarial drug artemisinin, could potentially reduce the transmission of malaria, along with other mosquito-borne illnesses, according to the study. The researchers believe that this method could assist malaria elimination efforts and mass administration of the drug.

“Getting patients to take medicine day after day after day is really challenging,” said lead author Andrew Bellinger, PhD, MD. “If the medicine could be effective for a long period of time, you could radically improve the efficacy of your mass drug administration campaigns.”

To create a long-term delivery method, drugs must be encased in a capsule that can withstand the stomach’s environment and release the contents over time. Once all of its contents are released, the capsule needs to be broken down and safely passed through the gastrointestinal tract.

With these standards in mind, the research team created the star-shaped drug delivery device that can be folded into a capsule. Each of the 6 arms are composed of polycaprolactone, a rigid polymer, and are loaded with the drugs. Each arm is attached to a rubber-like core by a linking device that will eventually break down.

After being swallowed, stomach acid dissolves the outer layer of the capsule, which then allows the 6 arms to be released. The star-shaped delivery device then expands, and is large enough to stay in the stomach without being pushed further into the digestive tract.

Researchers noted that while the delivery device resists these digestive forces, it will not cause any harmful blockage.

In studies involving pigs, investigators found that the drug is gradually released over a 2-week period of time. After this time, the link that joins the arms to the core dissolves, and lets the arms break off, according to the study. These arms are small enough to prevent harm to the digestive tract.

“This is a platform into which you can incorporate any drug,” said researcher Mousa Jafari, PhD. “This can be used with any drug that requires frequent dosing. We can replace that dosing with a single administration.”

The researchers also believe that this drug delivery system could potentially be used to improve clinical trials by making drug administration easier.

“It may help doctors and the pharma industry to better evaluate the efficacy of certain drugs, because currently a lot of patients in clinical trials have serious medication adherence problems that will mislead the clinical studies,” said researcher Shiyi Zhang, PhD.

The investigators also used mathematical modeling to determine the impact of this delivery approach on malaria campaigns. Their findings suggest that if this technology delivered ivermectin plus antimalarial drugs to 70% of a population, the reduction in disease transmission would be equivalent to 90% of the population being treated with antimalarials alone, according to the study.

The research team is also creating similar capsules that could potentially be used to treat tropical diseases, HIV, and tuberculosis.

“What we showed is that we stand to significantly amplify the effect of those campaigns,” said senior author Giovanni Traverso, PhD, MB. “The introduction of this kind of system could have a substantial impact on the fight against malaria and transform clinical care in general by ensuring patients receive their medication.”