BCHE and Alzheimer disease: In addition, it was found that administration of AD drugs in combination with chitosan nanocarriers can also contribute to an array of other advancements; such as enhanced antioxidant effect [75], improved inhibition of cholinesterases [2,42], increased half-life [42], lower effective doses [75], reduced toxicity [44] and masked pungency of actives during intranasal dosing [75].