Eventually, the team believes, monthly pills built using this technology could provide treatment for diabetes, high blood pressure drugs, Alzheimer's and more, freeing people from having to keep in mind to take daily medication. However, the capsules maintained these drug levels for almost a month, while the tablets last for only a day.
At this point, the drug is still highly experimental, and the researchers caution that it could be 3 to 5 years before it is tested in humans.
"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", says Robert Langer, the David H. Koch Institute Professor at MIT.
"There's a lot of stuff packed in there", Lipton said.
Women who use birth control pills have a significantly smaller hypothalamus volume, a region of the brain associated with anger and depression, than those who do not take oral contraceptive pills (OCPs), according to preliminary findings presented at the Radiological Society of North America (RSNA).
Today, women who want the convenience of long-lasting contraception can choose among various devices, from a weekly patch to a monthly vaginal ring to an IUD that lasts for years.
Structural effects of sex hormones, including oral contraceptive pills, on the human hypothalamus have never been reported, according to the researchers. Pills of all sorts generally pass through the body in a day. To ensure the pill survives the harsh environment of the human stomach, it is made of polyurethane that can withstand stomach acid, the researchers said.
"Coming up with a monthly version of a contraceptive drug could have a tremendous impact on global health", Kirtane says. Once in the stomach, the coating dissolves and the plastic device springs open into a six-armed star shape. The device is folded inside an ordinary-sized capsule.
MIT engineers have designed a capsule that unfolds in the stomach after being swallowed, and can gradually deliver one month's worth of a contraceptive drug.
After the month is up, the star-shaped system breaks apart at the links holding together the arms to the base and exits the body through the digestive tract.
In their earlier studies, the researchers loaded the capsules with drugs to treat malaria, as well as HIV drugs, which now have to be taken every day. They also are experimental, but longer-lasting pills one day could help patients with serious diseases better stick with treatment.
Indeed, the effects of oral contraceptives on the brain remain unclear.
The researchers loaded the contraceptive drug levonorgestrel into the arms of the device and found that by changing the concentrations of the polymers that they mix with the drug, they can control the rate at which it is released.
In a paper published today (Dec. 4) in Science Translational Medicine, a team led by Robert Langer, who runs one of the world's largest chemical engineering labs at MIT, and Dr. Giovanni Traverso, a gastroenterologist at Brigham and Women's Hospital and assistant professor of mechanical engineering at MIT, report on a polymer they created to survive in the harsh, acidic environment of the human stomach for about 30 days. "We see an enormous number of potential applications", says Langer, who, along with Traverso, founded the company Lyndra Therapeutics, to continue readying the "pill" for human testing.
The most important ingredients in most oral contraceptives, estrogen and a form of progesterone, are hormones that are active in the brain and trigger changes in reproductive organs to prevent pregnancy. That would alert women when it was time to take another monthly dose. Other questions include whether the device dissolves in the same way in different people.