New drug delivery method promises months-long effects with fewer injections

MIT engineers have prepared a new way to distribute some drugs in high doses with low pain, injuring them as a suspension of small crystals. Once under the skin, the crystals gather in a drug “depot” that can last for months or years, ending the need for frequent drug injections.

This approach can prove useful to distribute long -lasting contraceptives or other drugs that should be given for an extended period. Because drugs are spread in a suspension before injection, they can be administered through a narrow needle that is easy to bear patients.

“We showed that we can be very controlled, continuous delivery, for several months and even through a small needle.”

The lead writer of the paper, which appears Nature chemical engineeringThe former MIT and BWH Postdock Vivian are Feigs, who are now assistant professors of mechanical engineering at Stanford University; MIT graduate student Sanghyun Park; And Pier Rivano, a former visiting research scholar at Traverso Lab.

Easy injection

The project began as part of a project to expand contraceptive options, especially in developing countries.

“Overching target is to provide women access to a lot of different formats for contraception that are compatible with being used in the developing world, and compatible with a series of different time limitations of the duration of action,” Fag says.

“In our special project, we were interested in trying to combine the benefits of acting implants for a long time with ease of self-administrative injection.”

Injectable suspensions available in the United States and other countries are available, but these drugs are spread throughout the tissue after injections, so they work for only three months.

Other injectable products have been developed that can create long -lasting depots under the skin, but they usually require addition of pronounced polymers that can create a 23 to 98% solution by weight, making it more difficult to inject the drug.

The MIT and BWH team wanted to create a formulation that could be injected through a small-gauge needle and had lasted for at least six months and two years. He began to work with a contraceptive drug, called levonorgestral, a hydrophobic molecule that can make crystals.

The team found that these crystals were assembled in a highly compact transplant after crystal injection due to suspending these crystals into a special organic solvent. Because this depot can be formed without a large amount of polymer requirement, drug formulation can still be easily injected through a narrow-way needle.

The solvent, benzil benzoate, is biocampatible and has been used as a additive for the first injectable drugs. The team found that the solvent of the solvent of mixing with organic fluids is that the solid drug allows the crystal to self-decide into the depot under the skin after injections.

“The solvent is important because it allows you to inject the fluid through a small needle, but once, the crystals are self-gigant in a drug depot,” says Traveerso.

By changing the density of the depot, researchers can tune the rate on which drug molecules are released into the body. In this study, researchers showed that they can change the density by adding small amounts of polymer, a biodegradable polyester, a biodegradable polyester.

“By incorporating a very small amount of polymer – less than 1.6% of weight – we can modify the release rate of the drug, extending its duration by maintaining the injectionability. It displays the tuneability of our system, which can be engineered to adjust to other medical applications along with a wide range of contraceptive needs.”

Stable drug depot

Researchers tested their outlook by injecting drug solutions in mice with subcutaneous and showed that drug depots could remain stable and gradually release the drug for three months. After the end of three months of study, about 85% of the drug remained in the depot, suggesting that they may continue to release drugs longer.

“We guess that depots can last more for more than a year, based on subsequent analysis of our pregnant data. This initial study is going on to further validate their efficacy beyond this initial proof-off-concept,” Park says.

Once a drug depot is formed, they are sufficient to compact, allowing surgical removal, if the drug needs to be prevented before releasing.

Researchers say that this approach can lend themselves to distribute drugs for the treatment of HIV and tuberculosis along with neurocycatric conditions. They are now moving towards assessing its translation for humans by organizing advanced pre-priced pregnancy to evaluate the self-regulation in more clinically relevant skin environment.

“This is a very simple system that it is basically a solvent, medicine, and then you can add a little biorsorbal polymer. Now we are considering what signs we go after: Is this contraceptive? Is it other?

This story has been reinstated courtesy of MIT News (web.mit.edu/newsoffice/), A popular site that covers news about MIT research, innovation and teaching.