Researchers have developed a low-cost syringe design that could allow biologic medications to be injected subcutaneously, rather than having to be diluted and delivered intravenously.
The developers of the new design say the innovation could lower the costs and raise accessibility of treatment with these potent medications.
“Where drug delivery and biologics are going, injectability is becoming a big bottleneck, preventing formulations that could treat diseases more easily,” says Kripa Varanasi, PhD, a Massachusetts Institute of Technology (MIT) professor of mechanical engineering, in a press release.
“Drug makers need to focus on what they do best, and formulate drugs, not be stuck by this problem of injectability.”
Dr. Varanasi is the senior author on the research, which was published online ahead of print in Advanced Healthcare Materials (Aug. 24, 2020).
The Bill and Melinda Gates Foundation brought the challenge to develop a way to deliver high-concentration vaccines and biologic therapies to people in developing countries who could not easily travel to a formal medical setting, according to the release.
To address the challenge, Dr. Varanasi and his colleagues set out to create a way to reduce the amount of force needed to push viscous medications through an injector needle, which for many biologics normally exceeds what can be applied by hand.
In the current pandemic, Dr. Varanasi said, being able to stay home and subcutaneously self-administer medication to treat diseases such as cancer or auto-immune disorders is also important in developed countries such as the United States.
“Self-administration of drugs or vaccines can help democratize access to health care,” he said.
The new syringe system they have developed comprises two nested cylinders. The inner cylinder contains the viscous medication to be injected, while the outer layer contains a lubricating fluid. When the plunger is pressed, the medication is surrounded by a thin layer of the lubricant, reducing both the force needed for passage through the needle and sheer forces with the walls of the needle.
In the study, investigators found that 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 medications otherwise considered too viscous to be administered in that way.
“We can enable injectability of these biologics,” said the paper’s lead author, Vishnu Jayaprakash, a graduate student in MIT’s mechanical engineering department. “Regardless of how viscous your drug is, you can inject it, and this is what made this approach very attractive to us.”
The authors note that other approaches that have been tried previously to deliver high-viscosity medications all have limitations. Generally, high-viscosity medications, including biologics, are diluted and given intravenously, which requires a visit to a hospital or doctor’s office. Jet injectors, which shoot the drugs through the skin without a needle, are expensive and prone to contamination from backsplash. Injecting encapsulated drugs often results in their clogging the needle and involves additional complexity in the medication's manufacturing and release profiles. EpiPen-style syringes are also generally too expensive to be used widely.