Chitosan micro sized ODF (CBF), chitosan nano sized ODF (CNF) and chitosan nanofiber (CNfib) were prepared to release the donepezil drug quickly for Alzheimer's disease. CNF and CNfib were prepared from ionic gelation technique and electro-spinning process which were further examined under in vitro and in vivo animal model studies. Good thermal stability of CNfib (450 degrees C) when compared to CBF (325 degrees C) and CNF (305 degrees C). The particle size was below 150 nm in diameter for CNfib and 250 nm in diameter for CNF4 from TEM technique. In vitro antimicrobial activities for ODF and nanofibers were conducted by well diffusion method against Gram +ve and Gram -ve bacteria after 24h of incubation. From the in vitro release profile, the CNfib was competently showed rapid release of drug up to 97% than the thin film of CBF2 and CNF4 respectively in the initial period of 10 min. In vivo animal model studies demonstrated that the drug reached the maximum concentration within 3.5 h for chitosan nanofiber and nanofilm (CNF4). The chitosan nanofiber has given significantly faster absorption rate [1860.5 ngiml of AUC((0-infinity))]and the mean total area under curve was 161.71% on contrasted with chitosan nanofilm (CNF4). (C) 2017 Elsevier B.V. All rights reserved.