An Update on the Routes for the Delivery of Donepezil

Abstract

Dementia is a significant public health problem in the 21st century. Alzheimer’s disease (AD) is an essential factor in dementia. Currently, the drugs used for the treatment of AD are mainly acetylcholine inhibitors (AChEIs). As an AChEI, donepezil (DP) can improve patients’ cognitive ability with low side effects and has been accepted by most patients and doctors. For AD patients, the dosage regimen is also crucial due to aging and diseases. Although there are DP oral tablets on the market, there are still many problems to be solved. At present, more and more research is conducted to optimize the route of administration of DP to improve the self-administration of patients. The research fields of DP administration include oral administration, injection administration, intranasal administration, and transdermal administration. This Review is to present the development of different DP administrations and evaluates the advantages and limitations of those works, hoping to optimize the DP dosage regimen for AD patients.

Subcutaneous Implantable Microneedle System for the Treatment of Alzheimer’s Disease by Delivering Donepezil

“…As shown in Figure A, the prepared MNs consisted of an array of 10 × 10 needles with a height of 600 μm, a base diameter of 350 μm, and a spacing of 800 μm between the needles, and the surface of the needles was smooth without drug crystals precipitated. The height of the needle body of 600 μm was much more than the thickness of the human skin stratum corneum (50–100 μm), which ensures the delivery of drugs through the stratum corneum to the subcutis . The stratified structure of the upper and lower parts could be seen with the aid of rhodamine B as a simulated drug.…”

“…The height of the needle body of 600 μm was much more than the thickness of the human skin stratum corneum (50−100 μm), which ensures the delivery of drugs through the stratum corneum to the subcutis. 38 The stratified structure of the upper and lower parts could be seen with the aid of rhodamine B as a simulated drug. In the SEM image, the demarcation line between the two parts could be observed more microscopically.…”

Design, Synthesis and Evaluation of Catechol-Based Amyloid Beta Aggregation Inhibitors

“…Other drugs used to treat AD such as acetylcholine esterase (AChE) inhibitors and N-methyl-D-aspartic acid (NMDA) receptor antagonists are not disease-modifying and address only its symptoms. 13 Examples of these include donepezil (4), 14 memantine (5), 15 galanthamine (6) 16 and rivastigmine (7) 17 (Figure 4).…”

Intranasal Administration of Nanovectorized Docosahexaenoic Acid (DHA) Improves Cognitive Function in Two Complementary Mouse Models of Alzheimer’s Disease

“…This route of administration bypasses the BBB and allows the passage of molecules along the olfactory and trigeminal nerves, which are in direct contact with the CNS [14,15]. The efficacy of this system for CNS targeting has recently been validated in clinical trials for cerebral insulin delivery [16] and is being evaluated for other drugs such as acetylcholinesterase inhibitors [17]. The main advantages of the intranasal route of administration are (i) its accessibility, (ii) non-invasiveness, and (iii) its very low metabolic activity compared to the gastrointestinal wall, leading to high bioavailability [14,15].…”