Encapsulation of curcumin into nanoparticles

Abstract

Encapsulation of curcumin into five polymers, namely; ethyl cellulose (EC), methylcellulose (MC), methyl ether-terminated poly(ethylene glycol)-4-methoxycinna moylphthaloylchitosan (PCPLC), poly(vinyl-alcohol-co-vinyl-4-methoxycinnamate) with two degrees of 4-methoxycinnamoyl substitution (PB4-I and PB4-II) was performed by solvent displacement method. All five polymers could effectively form curcumin-loaded particles with more than 90% encapsulation efficiency at the loading of ~50%w/w, with polymer to curcumin weight ratio of 1:1. The photostability study indicated that the loaded curcumin was significantly more stable than free curcumin. In vitro experiments presented quickly and highest release of curcumin from ECMC and EC under acidic and neutral condition. In addition, curcumin was released in simulated gastric fluid more than simulated intestinal fluid while release of curcumin from ECMC is higher than EC. The oral bioavailability of curcumin-loaded EC (C-EC) and curcumin-loaded ECMC (C-ECMC) particles in mice showed their adherence to stomach mucosa and their ability to release curcumin into the circulation at a higher concentration and longer curcumin sustainability in the blood was also observed comparing to that of free curcumin. Both C-EC and C-ECMC particles showed comparable in vitro and ex vivo radical formation protection capacity with free curcumin. In addition, an in vitro skin penetration study revealed the strong fluorescent signal of curcumin in the porcine ear skin tissue, while the w/o lotion could enhanced skin penetration of C-EC and C-ECMC better than o/w lotion. The laser fluorescent scanning microscope (LFSM) pictures indicated that hair follicle was the main transportation route of the prepared curcumin-loaded nanoparticles.