Preparation and in vitro evaluation of donepezil loaded nanoparticular drug delivery systems

There are about 46 million dementia worldwide today. The cause of disease is unknown and there is currently no treatment to stop or slow the degenerative process.1 However, there are some symptomatic treatment approaches to partially improve the cognitive functions of Alzheimer' s Disease, to control emotional and psycologycal changes, and to improve the quality of life of patients with clinical practice. 2 Donepezil is a reversible cholinesterase inhibitor used in the treatment of Alzheimer' s Disease. The cholinergic system plays an important role in learning, memory, and severe memory impairment due to cholinergic dysfunctions in Alzheimer' s Disease. 3 New strategies are needed, such as osmotically opening the blood brain barrier or devoloping drug delivery systems, in order for drug molecule to bypass the blood brain barrier because of the inadequacy of traditional transport mechanisms. Interventional techniques that bypass blood brain barrier include the use of drug carrying nanoparticle systems and intranasal pathway.1 Polymeric nanoparticles protect nanoparticles in vitro and in vivo degradation, release drugs in a controlled manner, and offer the possibility of drug targeting.4 In this study, PLGA nanoparticles loaded with Donepezil agent were prepared by solvent evaporation technique. Several techniques have been tried for preparation of nanoparticles and the activity of these techniques in preparing nanoparticles has been observed. Parameters affecting the particle size were investigated and reported in the optimal technique for preparing Donepezil active substance loaded PLGA nanoparticles. For the characterization of the prepared nanoparticles, HPLC, FTIR, particle size measurements were performed, particle preparation efficiency, encapsulation efficiency and loading rates were calculated. Furthermore, the analytical method has been developed and its validity proved to be able to determine the Donepezil drug substance by the HPLC method.