Oral Insulin Works in Tests on Rats
Promising Early Results Mean People With Diabetes Could Soon Forgo Injections
Jan. 10, 2007 -- Oral insulin may be one step closer to becoming available
to people who now have to take shots for their diabetesdiabetes.
Scientists in Taiwan report success in early tests of an oral insulin
solution in diabetic rats. The solution hasn't been tested in people yet.
Currently, insulin can be taken by injection or, as in the case of the
recently approved Exubera, by inhalation.
"Multiple daily injections of insulin are currently the standard
treatment for insulin-dependent diabetic patients," write the Taiwanese
researchers, who include Hsing-Wen Sung, PhD, of Taiwan's National Tsing Hua
An oral drug would be "by far the most convenient and comfortable way of
delivering insulin," Sung's team writes.
But there have been roadblocks. "Protein drugs, like insulin, are
readily degraded" in the stomach, preventing pure oral insulin from
reaching the bloodstream to do its work, the researchers point out.
So Sung and colleagues bundled insulin with chitosan -- a chemical derived
from the shells of shrimp, crabs, and lobsters -- into tiny particles called
They then put these nanoparticles in an oral solution, which they tested on
diabetic male rats.
Lab tests showed the insulin reached the rats' bloodstream and lowered their
blood glucose (sugar) levels.
Further work is needed to see if the oral insulin solution works in people.
Other scientists have also attempted to make an oral insulin solution, but none
have reached the market.
The Taiwanese study appears in the journal Biomacromolecules.