MIT engineers have developed a new drug delivery method that could change long-term treatments with fewer injections and less discomfort
For this new drug delivery breakthrough, the researchers used tiny crystals suspended in a solution, which were injected under the skin. Once administered, these crystals self-assemble into a depot that can release medication gradually over an extended period, potentially for months or even years.
This could pave the way for long-lasting treatments such as contraceptives or therapies for diseases like HIV, reducing the need for frequent injections and improving patient compliance.
A new drug delivery system
The main goal of this research, which the Gates Foundation funded, is to create a drug delivery system that would be both effective and easy to administer, particularly in developing countries.
Current methods for long-acting injectable drugs often require large amounts of polymer, making injections more painful and difficult to administer. The MIT team hopes to overcome these challenges by developing a method that would be easier for patients to tolerate. Their approach uses a special formulation where the drug is suspended in a specific organic solvent, allowing it to be injected through a narrow, less painful needle. Once under the skin, the drug forms a compact depot, releasing the drug in a controlled and sustained manner.
Contraceptives and chronic disease treatment
The researchers focused on a contraceptive drug called levonorgestrel, which is known to form crystals. By suspending these crystals in the benzyl benzoate solvent, they could ensure that they assembled into a depot after injection, without the need for large amounts of polymer.
The solvent is biocompatible, meaning it is safe for use in the body, and its poor mixing ability with biological fluids helps the crystals form the depot at the injection site.
This technique allows for controlled drug release, which can be adjusted by modifying the density of the depot. The researchers demonstrated that by adding small amounts of a biodegradable polymer, they could tune the release rate of the drug, extending its duration without compromising the ease of injection.
The ability to tailor the release rate opens up possibilities for a range of medical applications, from contraceptives to treatments for chronic diseases that require long-term medication.
Exploring other therapeutic areas
The effectiveness of this system was tested in preclinical studies, where rats were injected with the drug formulation.
The results showed that the drug depots remained stable and released the medication gradually over three months. After the study, around 85% of the drug remained in the depot, suggesting that the treatment could last a lot longer than the tested period, potentially extending to over a year.
This finding suggests that the system has the potential to offer even longer-lasting treatments than current options available on the market.
The drug depots are also formed by this method are compact enough to be removed surgically if necessary, giving healthcare providers the option to halt treatment before the full drug release occurs.
This flexibility is another advantage of the new system, making it more adaptable to patient needs.
The future of long term drug delivery
The team is now exploring its use for other therapeutic areas, including treatments for neuropsychiatric disorders, HIV, and tuberculosis. By improving drug delivery systems, this innovation could significantly improve patient outcomes and ease the burden of long-term treatments.
In the next phase, the researchers plan to conduct advanced preclinical studies to assess the system’s performance in more clinically relevant environments and explore its feasibility for human use. The system’s simplicity, which relies on a combination of solvent, drug, and a small amount of biodegradable polymer, holds promise for many medical treatments, potentially transforming how long-term therapies are administered.
