Drug Delivery Systems as a Strategy to Improve the Efficacy of FDA-Approved Alzheimer’s Drugs

Abstract

Alzheimer’s disease (AD) is the most common form of dementia, with a high impact worldwide, accounting for more than 46 million cases. The continuous increase of AD demands the fast development of preventive and curative therapeutic strategies that are truly effective. The drugs approved for AD treatment are classified into acetylcholinesterase inhibitors and N-methyl-D-aspartate receptor antagonists. The therapeutic effectiveness of those drugs is hindered by their restricted access to the brain due to the blood–brain barrier, low bioavailability, and poor pharmacokinetic properties. In addition, the drugs are reported to have undesirable side effects. Several drug delivery systems (DDSs) have been widely exploited to address these issues. DDSs serve as drug carriers, combining the ability to deliver drugs locally and in a targeted manner with the ability to release them in a controlled and sustained manner. As a result, the pharmacological therapeutic effectiveness is raised, while the unwanted side effects induced by the unspecific distribution decrease. This article reviews the recently developed DDSs to increase the efficacy of Food and Drug Administration-approved AD drugs.

PAMAM-Calix-Dendrimers: Second Generation Synthesis, Fluorescent Properties and Catecholamines Binding

“…The nanometer size of dendrimer molecules comparable to that of the drug delivery systems facilitates their application in medical technologies [12]. They can form 10-500 nm nanoparticles, which well penetrate the cells and promote the immune response [13][14][15].…”

“…The dendrimer platform is ideally suited for binding drug molecules. These molecules can both be physically distributed inside the cavities of dendrimers and can bind to it through covalent bonds and a whole range of noncovalent interactions (electrostatic interactions, hydrogen bonding and van der Waals forces) [12,18]. High-generation dendrimers are mostly used in encapsulation and subsequent drug delivery [15].…”

Photobiomodulation in Alzheimer’s Disease—A Complementary Method to State-of-the-Art Pharmaceutical Formulations and Nanomedicine?

“…Drug delivery systems (DDSs) comprise a wide range of NPs, hydrogels, microformulations (microneedles, microparticles, microspheres and microemulsions) and NPs-loaded hydrogel (NLH) systems. Both NPs and microparticles can improve the therapeutic yield of drugs, protecting them from rapid degradation, improving their bioavailability and providing a more valuable release for the proposed site [ 187 , 209 , 210 ].…”

Intrathecal Pseudodelivery of Drugs in the Therapy of Neurodegenerative Diseases: Rationale, Basis and Potential Applications

“…Moreover, DDS contribute to the safety of pharmaceuticals during their whole delivery period by serving as various kinds of protective barriers that enclose them, minimizing the loss of active ingredients and any harmful impacts on patients. They are typically constructed at nanometric and micrometric levels in order to combine several qualities such as site-specificity, endurance, or external stimuli sensitivity [ 48 , 49 , 50 ].…”