Gels can give drugs a timely release. (biodegradable polymer coating releases drugs only when they reach large intestine)allows release of(Chemistry)(Brief Article)
Both doctors and patients would like to have ways to administer these drugs orally.
Emmanuel O. Akala, Pavla Kopeckov, and Jindrich Kopecek of the University of Utah in Salt Lake City have synthesized a biodegradable polymer that can work as a protective coating on pills, preventing the release of the drugs until they reach the large intestine.
The hydrogel takes advantage of the difference in acidity between the stomach and large intestine. The gel is unaffected in the stomach, but once it enters the less acidic large intestine, it takes up water and swells. "There will be an increase in the pore size of the hydrogel," Akala says, "so the drug diffuses out." The swelling is gradual, so the gel can pass through the small intestine to the large intestine before releasing large amounts of the drug.
Scientists are targeting the large intestine because "it's a less hostile environment" than the stomach, Akala says. Also, retention times there are long-between 15 and 64 hours-allowing plenty of time for drug absorption.
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|Article Type:||Brief Article|
|Date:||Sep 7, 1996|
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