Current Updates on Nanotechnology-based Drug Delivery Platforms for Treating Alzheimer's with Herbal Drugs.

Alzheimer's disease (AD) is an irreversible brain disorder that led to memory loss and disrupts daily life. Earlier strategies to treat AD such as acetylcholinesterase inhibitor (AChEI) drugs are not showing effectiveness due to the inability to cross the blood-brain barrier. Moreover, traditional AChEI provides limited efficacy in terms of bioavailability and solubility for treating AD treatment. Many of the current drugs such as donepezil taken to treat the disease exhibited harmful side effects. Hence, researchers are keen to find the alternative effective therapeutic agents for treating AD. This review summarizes the recent advancement in nanotechnology-based drug delivery systems of herbal drugs such as Curcumin, Ginkgo biloba, Salvia officinalis, etc for the prevention and cure of AD. Herbal drugs proved useful in treating neuronal disorders such as AD but exhibited some limitations like low bioavailability via oral drug delivery. Such limitations were overcome by tagging these drugs by nanoparticles which enables them to cross the blood-brain barrier and offer the delivery of greater concentration of herbal drugs to the brain. Inorganic nanoparticle-based drugdelivery systems such as gold nanoparticles and magnetic nanoparticles, organic nanoparticulate systems like polymeric micelles and dendrimers, and solid polymeric nanoparticles were some of the effective methods that have earlier shown potential for enhancing the delivery of herbal drugs to the brain. Long-term repeated injection of drugs loaded on nanomaterials can lead to the accumulation of nanomaterials in the body without timely and effective degradation which can cause serious issues to the brain. Hence, nanotechnology-based strategies should involve the formulation of nontoxic nanoparticles in such a way that they can significantly transport the drugs across the BBB followed by effective degradation of nanoparticles.