Due to the nature of the human body, certain medications need to be administered in a certain way. Some biologic drugs, like insulin, antibodies, and vaccines, are not effective when taken orally and must be delivered via injection. However, this could be about to change. A new drug delivery system has been tested in pigs that delivers medication directly to gastrointestinal tissues via an oral capsule using microneedles. The research was led by Giovanni Traverso and Carl Schoellhammer, both of MIT, and the paper was published in the Journal of Pharmaceutical Sciences.
“This could be a way that the patient can circumvent the need to have an infusion or subcutaneous administration of a drug,” Traverso said in a press release.
The prototype device itself is an acrylic capsule about two centimeters long and one centimeter wide that can be taken orally, roughly the size of a large multivitamin. The capsule is designed to protect the medication inside until it reaches the GI tract. Once the capsule has reached its target destination, it dissolves and exposes the drug reservoir that is covered with five-millimeter-long needles. The needles pierce the intestines when the tissue contracts, delivering the drug directly.
Currently, the test has only been performed with insulin. However, the researchers believe that it could work even better to deliver antibodies for use in cancer treatment, as well as for treating autoimmune disorders, including arthritis or Crohn's disease. The nature of these treatments has been hard to administer orally, leaving more invasive methods like injections as the best means of delivery.
“The large size of these biologic drugs makes them nonabsorbable. And before they even would be absorbed, they’re degraded in your GI tract by acids and enzymes that just eat up the molecules and make them inactive,” Schoellhammer added.
This degradation is prevented by the capsule until it can be directly applied with the microneedles. The intestines do not have pain receptors, which prevents the drug administration from being painful, and the researchers don't believe that the needles would cause any unseen damage to the tissue. Even so, the team is working to refine the device by making the needles out of a more readily degradable material, should they detach and get stuck in the tissue.
This safety is matched by its efficacy. When the capsule was used to administer insulin to pigs, the researchers found that the blood glucose levels were regulated faster and more effectively than by traditional injections.
“The kinetics are much better, and much faster-onset, than those seen with traditional under-the-skin administration,” Traverso explained. “For molecules that are particularly difficult to absorb, this would be a way of actually administering them at much higher efficiency.”