Breakthrough Drug Delivery System Promises More Convenient Treatments

Engineers Develop Revolutionary Drug Delivery System for Long-Lasting Treatments

In the pursuit of improving drug delivery systems, engineers at the Massachusetts Institute of Technology (MIT) have developed a groundbreaking new method that could revolutionize the way certain drugs are administered. This innovative approach involves injecting a suspension of tiny drug crystals, which self-assemble into a depot once injected under the skin. The result? A sustained drug release over months, or even years, with a significantly less painful injection experience. This development is set to address a major hurdle in drug administration, especially for long-term treatments that require fewer injections, improving both patient experience and compliance.

The Need for Long-Lasting Drug Delivery

For many chronic conditions, regular medication is essential to maintaining health. However, traditional drug delivery methods often involve frequent injections or daily pills. These frequent doses can be burdensome, especially for patients dealing with conditions like contraceptive needs, neuropsychiatric disorders, or infectious diseases like HIV and tuberculosis. Moreover, injections can be painful and stressful for many patients, contributing to poor adherence to treatment regimens.

In an effort to make drug administration more efficient and comfortable, researchers have been exploring ways to create long-lasting drug delivery systems that reduce the frequency of injections while still ensuring that the drugs remain effective over time. The latest innovation from MIT engineers provides a solution that could change the landscape of medical treatments by offering patients a longer-lasting option without the need for frequent visits to the doctor.

How the New Drug Delivery System Works

The new system developed by MIT and Brigham and Women's Hospital (BWH) involves suspending a drug in a solution of tiny crystalline particles. Once injected under the skin, these drug crystals self-assemble into a compact depot that can release the drug gradually over an extended period of time. The beauty of this system lies in its simplicity—by using a biocompatible solvent and minimal polymers, the drug is easily injected through a small needle, significantly reducing the pain and discomfort associated with traditional injections.

Giovanni Traverso, an associate professor of mechanical engineering at MIT, explains that this method allows for "very controlled, sustained delivery" of the drug, potentially lasting for months or even years. This method not only ensures consistent drug delivery but also eliminates the need for frequent injections, which is especially beneficial for patients undergoing long-term treatments.

The Importance of Benzyl Benzoate in the Formula

One of the key components of the MIT team’s success is the solvent used in the formulation—benzyl benzoate. This solvent has been used in injectable drug formulations before, but the MIT team discovered that its unique properties allow the drug crystals to form a depot under the skin after injection. Once injected, the benzyl benzoate causes the drug crystals to self-assemble into a solid depot, allowing for a gradual release of the drug over an extended period.

This is a critical feature of the system, as it allows the drug to be delivered effectively without the need for large amounts of precipitating polymers that could make the injection more difficult or painful. The low polymer content also ensures that the injection is easier to tolerate, making it an attractive option for patients who require regular treatments.

A Potential Game Changer for Contraception

The research began with a focus on improving contraceptive options, particularly for women in developing countries. The Gates Foundation funded the initial work, aiming to create a long-acting, easy-to-administer contraceptive option. Current injectable contraceptives are effective but require frequent injections, which can be a barrier to consistent use, especially in regions with limited healthcare access.

The MIT team’s new system aims to combine the benefits of long-acting implants with the convenience of self-administered injectables. By suspending levonorgestrel, a commonly used contraceptive drug, in the tiny crystals, they were able to create a depot that could last for months and even years, offering women a more convenient, longer-lasting contraceptive option.

Tuning the Drug Release Rate

In their experiments, the MIT team showed that by adding small amounts of biodegradable polymers, such as polycaprolactone, they could alter the density of the drug depot. This, in turn, allowed them to fine-tune the rate at which the drug is released. By modifying the formulation slightly, they could control how long the drug would remain in the body, extending its duration while maintaining the ability to inject it through a small needle.

"We can modulate the drug release rate and tailor it to the needs of different therapeutic applications," says Sanghyun Park, a graduate student at MIT and lead author of the study. This flexibility opens up possibilities for a range of long-term treatments, from contraception to chronic disease management.

Successful Preclinical Trials

To test the effectiveness of their new system, the MIT team performed preclinical studies on rats. After injecting the drug solution subcutaneously, they found that the drug depot remained stable and continued to release the drug gradually over a period of three months. After the study ended, about 85% of the drug remained in the depot, indicating that it could continue to release the drug for even longer.

"We anticipate that the depots could last for more than a year based on our analysis of preclinical data," says Park. This extended duration could be a game changer for patients who require long-term treatment but find frequent injections inconvenient or uncomfortable.

Applications Beyond Contraception

While the initial research focused on contraceptives, the potential applications for this drug delivery system go far beyond reproductive health. The technology could be adapted for the treatment of chronic conditions such as HIV, tuberculosis, and neuropsychiatric disorders, where long-lasting drug delivery is often necessary. Researchers are currently exploring how this system could be applied to other areas of medicine, making it a versatile solution for a variety of diseases.

Future Prospects and Human Trials

The MIT team is now working on advanced preclinical studies to assess the translation of this drug delivery system to humans. These studies will explore how well the crystals self-assemble under human skin and whether they can be adapted for use with different drugs. As they move toward clinical trials, they hope to refine the technology further and begin applying it to real-world treatments.

"This is a very simple system, but it has the potential to be transformative," says Traverso. "We are excited to explore its applications for a wide range of diseases and conditions."

Conclusion: A Revolutionary Step Forward in Drug Delivery

The development of a drug delivery system that allows for sustained, long-term treatment through a simple injection is a significant breakthrough in medical technology. By using a suspension of tiny crystals that self-assemble into a drug depot, MIT engineers have created a solution that could change the way many drugs are delivered. Whether it's for contraception, chronic disease management, or other therapeutic applications, this system has the potential to improve patient comfort and compliance, providing a simple yet effective way to manage long-term treatments.

Learn more: https://www.nature.com/articles/s44286-025-00194-x