Preparation and encapsulation techniques of chitosan microsphere for enhanced bioavailability of natural antioxidants

Reactive oxygen species (ROS), induced by medical and life irradiation, have led to diverse diseases. Natural antioxidants (NAs) have been widely used to protect the body from the harmful effects of ROS. NAs have biocompatible properties but their bioavailability in the body is very low. This article discusses possible solutions to improve the bioavailability using several preparation and encapsulation techniques for microspheres using chitosan as a carrier. The first is the emulsion technique that controls particle size (0.5–1000 μm) according to the speed (RPM) of the agitator. The second technique discussed is spray drying-a very simple method that can control particle size (5–5000 μm) according to the nozzle size and discharge pressure. The third is the extrusion technique, which can control particle size (250–2500 μm) according to the syringe pore size. These techniques have enormous potential for use as drug delivery systems (DDS) in the functional food and biomedical field industries.