Chitosan/Fucoidan pH Sensitive Nanoparticles for Oral Delivery System

Abstract A rationally designed oral delivery carrier must overcome various significant barriers in the gastrointestinal (GI) tract prior to delivery to the bloodstream. One of these barriers is the low pH of the gastric medium in the stomach. The aim of this study is to create pH‐sensitive nanoparticles for oral drug delivery to protect drugs from deterioration. The nanoparticles were prepared by the positively charged chitosan (CS) and negatively charged fucoidan (F) through the ionic‐gelation method. The structures of CS/F nanoparticles were characterized by Fourier transform infrared spectroscopy, particle size analyzer and transmission electron microscopy. Results indicated that the CS/F nanoparticles were ionized to a diameter of 200‐300 nm at a pH of 1.2. The CS/F nanoparticles became larger and unstable as the pH increased. Curcumin (Cur), an antitumor drug, is encapsulated in CS/F NPs for in vitro release study. The encapsulated Cur was sustained released as the pH increased, especially when the weight ratio of chitosan to fucoidan was 1:1. According to the results mentioned above, CS/F nanoparticles are effective pH‐sensitive carriers, and they have a great potential application in an oral delivery system.