For protein-based drugs such as insulin to be taken orally rather than injected, bioengineers need to find a way to shuttle them safely through the stomach to the small intestine where they can be absorbed and distributed by the bloodstream. Progress has been slow, but in a new study, researchers report an important technological advance: They show that a “bioadhesive” coating significantly increased the intestinal uptake of polymer nanoparticles in rats and that the nanoparticles were delivered to tissues around the body in a way that could potentially be controlled.
The results of these studies provide strong support for the use of bioadhesive polymers to enhance nano- and microparticle uptake from the small intestine for oral drug delivery,” wrote the researchers in the Journal of Controlled Release, led by corresponding author Edith Mathiowitz, professor of medical science at Brown University.
In the new study, which appeared online June 21, Mathiowitz put one of her most promising coatings, a chemical called PBMAD, to the test both on the lab bench and in animal models. Mathiowitz and her colleagues have applied for a patent related to the work, which would be assigned to Brown University.
The researchers used particles about 500 nanometers in diameter made of two different materials: polystyrene, which adheres pretty well to the intestine’s mucosal lining, and another plastic called PMMA, that does not. They coated some of the PMMA particles in PBMAD, to see if the bioadhesive coating could get PMMA particles to stick more reliably to the intestine and then get absorbed.
Measurements showed that the rats absorbed 66.9 percent of the PBMAD-coated particles, 45.8 percent of the polystyrene particles and only 1.9 percent of the uncoated PMMA partcles.
(Cited from World Pharma News).
Reineke, Cho et al. – Journal of Controlled Release – June 2013