New syringe technology could make the 'uninjectable' injectable

Researchers have designed a simple, low-cost device for subcutaneous injection of viscous formulations.

The technology makes it possible to inject high-concentration drugs and other therapies subcutaneously. It was developed as a solution for highly effective, and extremely concentrated, biopharmaceuticals, which typically are diluted and injected intravenously.

“Where drug delivery and biologics are going, injectability is becoming a big bottleneck, preventing formulations that could treat diseases more easily,” said Kripa Varanasi, MIT professor of mechanical engineering. “Drug makers need to focus on what they do best, and formulate drugs, not be stuck by this problem of injectability.”

Researchers designed a system that would make subcutaneous injection of high-concentration drug formulations possible by reducing the required injection force, which exceeded what is possible with manual subcutaneous injection with a conventional syringe.

In their system, the viscous fluid to be injected is surrounded with a lubricating fluid, easing the fluid’s flow through the needle. With the lubricant, just one-seventh of the injection force was needed for the highest viscosity tested, effectively allowing subcutaneous injection of any of the more than 100 drugs otherwise considered too viscous to be administered in that way.

Because of their high viscosities, administering the drugs subcutaneously has involved methods that have turned out to be impractical and expensive.

Therapeutic gels — used in bone and join therapies, as well as for timed-release drug delivery, among other uses — could also be more easily administered using the syringe developed by the researchers.

Varanasi concluded: “There should be no reason why this approach, given its simplicity, can’t help solve what we’ve heard from industry is an emerging problem,” he says. “The foundational work is done. Now it’s just applying it to different formulations.”