Molecular dynamics simulation of self-assembly in a nanoemulsion system

Nanoemulsions can be applied as delivery systems that improve solubilization capacity for poorly soluble drugs, and enhance the drug loading. In this work, a molecular self-assembly of a nanoemulsion composed of benzalkonium chloride as surfactant, cyclohexane as oil phase, and ethanol as co-surfactant in water, was investigated by three 1 mu s coarse-grained molecular dynamics simulations. Simulation results showed that the oil molecules placed in the hydrophobic core of the nanoemulsion and made its size larger, while the polar terminal groups of benzalkonium chloride chains dominated the surface. The ethanol co-surfactant molecules distributed throughout the system so that they did not concentrate in the hydrophilic shell of the nanoemulsion. After formation of the droplet, it remained stable until the end of the simulation. The nanoemulsion structure was compact and exhibited a prolate ellipsoid shape. The average value of radius of gyration of the nanoemulsion was 1.68 nm and physical radius, determined from the radius of gyration was 2.17 nm.