Rivastigmine and Emerging Nanotechnological Strategies for Targeted Delivery: A Comprehensive Review

Abstract:

Alzheimer’s disease affects millions of people globally; it is an irreversible and incurable disease, characterized by gradual cognitive decline as well as pathophysiological changes including the presence of senile plaques and neurofibrillary tangles. There are several risk factors associated with Alzheimer’s disease, including elevated blood pressure, blood sugar concentration, alcohol consumption, smoking, and sleep disturbances. Rivastigmine is an FDA-approved cholinesterase inhibitor used to treat Alzheimer’s disease. It is available as oral solutions, capsules, and transdermal patches. Oral administration can lead to detrimental and off-target effects such as nausea and vomiting, and the use of patches can cause irritation and rashes. Across various systems, including the Cardiovascular (CVS), Gastrointestinal (GI), immunological, dermatological, and respiratory systems, rivastigmine has been associated with effects that further necessitate targeted drug delivery. Novel drug delivery systems such as Liposomes, Polymeric Nanoparticles, Dendrimers, Solid Lipid Nanoparticles (SLNs), Nanostructured Lipid Carriers (NLCs), nano-emulsions, and Mesoporous Silica Nanoparticles (MSNs) have been developed to address the limitations of conventional dosage forms. These new formulations possess the ability to increase drug loading capacity, enhance penetration across the BBB, reduce expulsion, and offer controlled release of the drug. As a result, rivastigmine can be targeted to the intended site, with fewer off-target effects. However, formulation-specific toxicity may still occur. Positive off-target effects, such as improved appetite, protection against malnutrition, and evidence of advantage in treating colitis, were also observed with rivastigmine. However, detailed studies of its mechanism of action are needed to provide a scientifically sound justification for repurposing rivastigmine. Google Scholar and PubMed were searched for literature for this review and included studies that met the criteria.