Chitosan Nanoparticles Protect Antioxidants

Chitosan Nanoparticles Protect Antioxidants
Biopolymeric coating could enhance oral delivery

A biopolymeric nanoparticle protected antioxidants from digestive juices, allowing their controlled release over time, according to researchers.
The use of nanoparticles for drug delivery is not new but would be a novel approach for delivering antioxidants to the body.—Ken Ng, PhD, Monash University

The natural polymer chitosan could allow more efficient oral administration of antioxidant catechins, which have poor oral bioavailability, the researchers said.
“The use of nanoparticles for drug delivery is not new but would be a novel approach for delivering antioxidants to the body,” Ken Ng, PhD, a lecturer in pharmaceutical sciences at Monash University in Victoria, Australia, said in an email to PFQ.
Dr. Ng and his colleagues at Monash, Ian Larson, PhD, and graduate student Admire Dube, are preparing their findings for publication in the International Journal of Pharmaceutics.
Dr. Ng said catechins are found in fruits, green tea, wine, and other foods but last only hours in the gastrointestinal environment. These flavonoids are useful not only for their antioxidant properties but also for other biological attributes, including anti-inflammatory, vasodilatory, neuroprotective, and anticancer properties, he said.
“Recently, there has been interest in the use of polymeric nanoparticles as delivery vehicles to improve the oral bioavailability of drugs,” Dr. Ng said. Chitosan, a biopolymer derived from shellfish, is biocompatible and biodegradable, and it adheres to the intestinal mucosal layer, he said.
“We anticipate that encapsulation of catechins in polymeric nanoparticles will address their poor oral bioavailability,” Dr. Ng said.
In their current work, the researchers entrapped (+)-catechin in nanoparticles of chitosan-tripolyphosphate and chitosan-alginate and exposed them in vitro to simulated intestinal fluids. The protected (+)-catechin demonstrated controlled release, according to Dr. Ng.
The next step is to compare the oral bioavailability of catechin-loaded nanoparticles with catechin only in a rat model, Dr. Ng said. “Human trials will have to wait until dosage and toxicological parameters are sorted out in an animal,” he said.