This book presents a new facile route for the isolation of cellulose nano-crystals (CNC) which is also known as nanocellulose. The fabrication of cellulose based nanocomposites by simple film casting technique and the studies on how CNC influences the properties of the MC in the nanocomposites have been presented in this book. The synthesized nanocomposites have shown improved UV resistance, mechanical, barrier, and thermal properties. FTIR results established the physicochemical compatibility between the drug, MC and CNC in nanocomposites. In vitro permeation studies performed by using Franz diffusion cell revealed diffusion mediated sustained drug release from the devices due to the presence of interaction between MC and CNC through H-bonding, electrostatic interaction between the hydrophilic polymer/CNC chains with the drug and the formation of tortuous path. The results from the nanocomposites prove that it can be applied for edible packaging and transdermal drug delivery.