Production methods for nanodrug particles using the bottom-up approach

This review focuses on bottom-up processes such as precipitation (or crystallisation) and single droplet evaporation to produce nanoparticles containing largely pure therapeutics for pharmaceutical applications. Suitable precipitation techniques involve the use of high-gravity, confined impinging liquid jet mixing, multi-inlet vortex mixing, supercritical fluids, and ultrasonic waves. Droplet evaporation methods are spray-based, including nanospray drying, aerosol flow reactor method, spraying of low-boiling point solvent under ambient conditions and electrospraying of low-electrical conducting solutions. A key to the success of yielding stable nanoparticles in these various techniques is to control the particle growth kinetics through evaporation rate of the droplets or mixing rate during precipitation. (C) 2011 Elsevier B.V. All rights reserved.