Source : Thailand Medical News Dec 05, 2019 4 years, 11 months, 2 weeks, 5 days, 18 minutes ago
MIT medical researchers have developed an
oral contraceptive that only has to be taken once a month, which could reduce unintended pregnancies that result from forgetting to take a daily dose. This kind of monthly
contraceptive could have a significant impact on the health of women and their families, especially in the developing world, the researchers say.
Currently,
oral contraceptives are one of the most popular forms of birth control: Globally, about 13.5 percent of women aged between 15 and 49 use them. However, their effectiveness depends on being taken every day, and it is estimated that about 8 percent of women taking birth control pills become pregnant each year
Dr Robert Langer, the David H. Koch Institute Professor at MIT told
Thailand Medical News,"We are hopeful that this work the first example ever of a month-long pill or capsule to our knowledge will someday lead to potentially new modalities and options for women's health as well as other indications."
The
monthly contraceptive is contained within a gelatin-coated capsule and can carry three weeks' worth of a
contraceptive drug. This capsule remains in the stomach after being swallowed and gradually releases the drug. Tests in pigs showed that this kind of drug release can achieve the same concentration of the drug in the bloodstream as taking a daily dose.
The senior authors of the study, which appears today in
Science Translational Medicine are Dr Langer and Dr Giovanni Traverso, an assistant professor of mechanical engineering at MIT and a gastroenterologist at Brigham and Women's Hospital, Dr Ameya Kirtane, a senior postdoc at MIT's Koch Institute for Integrative Cancer Research, and Dr Tiffany Hua, a former technical associate at MIT, are the lead authors of the paper.
The
monthly contraceptive pill is based on star-shaped drug delivery systems that the MIT team previously developed, which can remain in the digestive tract for days or weeks after being swallowed. The delivery systems are placed in gelatin capsules that dissolve once they reach the stomach, allowing the folded arms of the star to expand and slowly release their payload.
In past studies, the researchers loaded the capsules with drugs to treat malaria, as well as HIV drugs, which currently have to be taken every day. Much of this work has been funded by the Bill and Melinda Gates Foundation, which urged the team to adapt the capsule to deliver long-lasting contraceptive drugs. Previous research has suggested that people are better at remembering to take medicine when they have to take it only weekly or monthly, instead of daily.
To ensure that their new contraceptive pill last for three to four weeks, the researchers had to incorporate stronger materials than those used in the earlier versions, which could survive in the harsh environment of the stomach for up to two weeks.
The researchers tested materials by soaking them in simulated gastric fluid, which is very acidic, and found that two types of polyurethane worked best for the arms and the central core of the star.
The medical researchers loaded the contraceptive drug levonorgestrel into the arms of the device and f
ound that by changing the concentrations of the polymers that they mix with the drug, they can control the rate at which it is released. Once the capsule reaches the stomach it expands and becomes lodged in place.
In animal models, the researchers found that the capsules could release the drug at a fairly constant rate for up to four weeks. The concentration of the drug found in the pigs' bloodstream was similar to the amount that would be present after ingesting daily levonorgestrel tablets. However, the capsules maintained these drug levels for nearly a month, while the tablets last for only a day.
For human uses, the capsule would be designed to break down after three or four weeks and exit the body through the digestive tract. The researchers are working on several possible ways to trigger the arms to break off, including through changes in pH, changes in temperature, or exposure to certain chemicals.
The company founded by Dr Langer, Dr Traverso, and others, Lyndra Therapeutics, recently received a $13 million grant from the Gates Foundation to further develop the
monthly contraceptive pill so that it can be tested in humans.
Dr Traverso added, "Through the development of these technologies, we aim to transform people's experience with taking medications by making it easier, with more infrequent dosing in the first once-a-month, orally delivered drug system. We're very committed to getting these technologies to people over the coming years."
The team anticipates human tests may be possible within the next year or two.
Enhanced
contraception not only has health benefits, but also makes it easier for women to go to school and financially support themselves and their families. However, according to the World Health Organization, 216 million women of reproductive age in developing countries who want to avoid
pregnancy are not using a modern contraceptive method, such as birth control pills.
Dr Kirtane added, "Coming up with a monthly version of a
contraceptive drug could have a tremendous impact on global health. The impact that
oral contraceptives can have on human health and gender equality cannot be overstated."
The medical researchers also believe that such a pill could be appealing for women who would prefer a long-lasting
oral contraceptive over other long-term
contraceptives such as intrauterine devices.
Dr Kirtane explained, "Even with all these long-acting devices available, there's a certain population who prefers to take medications orally rather than have something implanted. For those patients, something like this would be extremely helpful."
Reference : A.R. Kirtane el al., "A once-a-month oral contraceptive," Science Translational Medicine (2019). . stm.sciencemag.org/lookup/doi/ … scitranslmed.aay2602
