This review highlights the recent developments in the area of nanocarrier-based targeted delivery systems for both conventional drugs and therapeutic agents of increased complexity. A challenging objective of targeted drug delivery is the development of novel nanocarriers for the delivery of protein/peptide drugs via the oral, pulmonary and nasal administration routes. The nanocarriers need to be biocompatible, biodegradable, non-toxic and stable in biological media, to protect their payload and deliver it to desired sites within the body, preferentially in a temporally regulated manner, and on the other hand to be manufactured in a simple scalable manner, with relatively low cost. (c) 2012 Canadian Society for Chemical Engineering