Bioadhesive chitosan nanoparticles: Preparation and characterization

Bioadhesive chitosan nanoparticles (CS NPs) were prepared for encapsulation of catechin and evaluation of their mucoadhesive potential that leads to enhanced oral bioavailability of catechin. CS NPs and catechin loaded CS NPs were obtained by ionic gelation between the CS and sodium tripolyphosphate (TPP). Particle size distribution analysis confirmed the size ranges, 110 ± 5 nm and 130 ± 5 nm for CS NPs and catechin loaded CS NPs, respectively. TEM indicated smooth and spherical nanoparticles. FTIR and DSC showed no significant interactions between catechin and CS after encapsulation and cross-linking. Entrapment efficiency of 90% was achieved with a weight ratio of 2:1 (CS:TPP) at pH 5.5. In vitro release of catechin from CS NPs was 32% within 24 h and exhibited 40% and 32% mucoadhesivity for catechin loaded CS NPs and CS NPs, respectively, demonstrating potential for controlled release of catechin in GIT.