Many drugs cannot be taken orally as they get broken down in the gastrointestinal (GI) tract by enzymes before they're absorbed. Until now, these drugs have had to be delivered via injection, which can be painful, and previous attempts to ‘encapsulate’ them have been expensive, impractical and ultimately unsuccessful.
But there may be a better solution. Published in the Journal of Pharmaceutical Sciences, researchers at Massachusetts Institute of Technology (MIT) in the US have collaborated with the Massachusetts General Hospital to design an acrylic capsule that's covered with tiny stainless steel needles.
The capsule can be swallowed, and once it reaches the GI tract, the pH-sensitive coating dissolves, uncovering the small micro-needles. The drug is then released into these needles, which slowly inject it directly into the stomach lining. Thankfully, as there are no pain receptors in the GI tract, this process is painless.
The prototype has been tested on pigs, where a needle-coated capsule containing insulin - the hormone required by diabetics that regulates blood sugar levels - was administered orally. The results showed that this insulin was successfully injected into the stomach lining, small intestine, and colon, and that there were no signs of tissue damage as the capsule moved through the digestive tract.
Of particular interest was the fact the pigs’ blood glucose levels decreased more rapidly after they were given insulin via the needle-coated capsule than when the drug was administered via subcutaneous injection, suggesting this new method may actually be more effective.
“The kinetics are much better, and much faster-onset, than those seen with traditional under-the-skin administration,” said Giovanni Traverso, one of the lead researchers of the study, in a press release.
The team predict that this revolutionary form of drug delivery will be beneficial for vaccines, as well as antibodies required in cancer treatments and other autoimmune disorders such as Crohn’s disease.
“For molecules that are particularly difficult to absorb, this would be a way of actually administering them at much higher efficiency,” said Traverso.
The next step is to refine the capsule so that it is made of a degradable polymer that can naturally release its drug alongside the contractions of the digestive tract.
This new method of drug delivery can potentially redefine the face of immunisation and other needle-administered practises. The real question is, will people feel more comfortable with many small needles inside of them, as opposed to one large one outside of them?
Watch more about the new drug-delivery method: