Therapeutic effectiveness of Donepezil hydrochloride in combination with butylphthalide for post-stroke cognitive impairment.

OBJECTIVE: To study the therapeutic effectiveness of donepezil hydrochloride (DPZ) in combination with butylphthalide (BP) for the treatment of post-stroke cognitive impairment (PSCI). METHODS: In this retrospective study, the clinical data of 125 PSCI patients treated at the First Affiliated Hospital of Harbin Medical University from December 2019 to December 2023 were collected and analyzed. The patients were grouped into a joint group (n=75, receiving DPZ + BP) and a control group (n=50, receiving DPZ alone) according to their treatment regimen. Inter-group comparisons were then carried out from the perspectives of therapeutic effectiveness, safety (constipation, abdominal distension and pain, and gastrointestinal reactions), cognitive function (Montreal Cognitive Assessment Scale [MoCA], Chinese Stroke Scale [CSS]), Activities of Daily Living Scale (ADL), and serum biochemical indexes (neuron-specific enolase [NSE], high-sensitivity C-reactive protein [hs-CRP], nitric oxide [NO], and malondialdehyde [MDA]). In addition, a univariate analysis was carried out to identify factors affecting therapeutic effectiveness in PSCI patients. RESULTS: The joint group showed significantly better therapeutic effectiveness compared to the control group (P<0.05). There was a significant correlation between the type of stroke, treatment method, and therapeutic effectiveness in PSCI patients (P<0.05). There was no significant difference in the total incidence of adverse reactions (P>0.05). After the treatment, compared to the control group, the joint group demonstrated significant improvements in MoCA and ADL scores (all P<0.05) and reductions in CSS scores and levels of NSE, hs-CRP, NO, and MDA (all P<0.05). CONCLUSIONS: DPZ in combination with BP is highly effective for the treatment of PSCI. It positively affects cognitive function and ADL, alleviates neurological deficits, and reduces abnormal serum biochemical indices without increasing the risk of adverse reaction.

Chiral pyrrolidines as multipotent agents in Alzheimer and neurodegenerative diseases.

In pharmaceutical science and drug design the versatility of the pyrrolidine scaffold relating to spatial arrangement, synthetic accessibility and pharmacological profile is a largely explored and most likely interesting one. Nonetheless, few evidences suggest the pivotal role of pyrrolidine as scaffold for multipotent agents in neurodegenerative diseases. We then challenged the enrolling in the field of Alzheimer disease of so far not ravelled targets of this chemical cliché with a structure based and computer-aided design strategy focusing on multi-target action, versatile synthesis as well as pharmacological safeness. To achieve these hits, ten enantiomeric pairs of compounds were obtained and tested, and the biological data will be here presented and discussed. Among the novel compounds, coumarin and sesamol scaffolds containing analogues resulted promising perspectives.

Efficacy and safety of ginkgo biloba extract combined with donepezil hydrochloride in the treatment of Chinese patients with vascular dementia: A systematic review meta-analysis.

Objective: To conduct a meta-analysis of the effectiveness and safety of ginkgo biloba extract combined with donepezil hydrochloride vs. donepezil for the treatment of vascular dementia (VaD). Methods: Four English databases (PubMed, EMBASE, Web of Science, Cochrane Library) and four Chinese databases [the China National Knowledge Infrastructure Wanfang DATA, the Chongqing VIP Database (VIP), China Biomedical Database (CBM)] were manually searched for literature published from dates of the inception of the databases to September 2023. The randomized controlled trials (RCTs) of ginkgo biloba extract with donepezil hydrochloride vs. donepezil for the treatment of VaD were included. Relevant literature was screened, and the data in the included studies were extracted for quality assessment according to the Risk of bias tool. Results: A total of 1,309 participants were enrolled in the 15 RCTs. Of these, 656 participants were in the experimental group (ginkgo biloba extract combined with donepezil) and 653 participants were in the control group (donepezil).The results showed that combination therapy was superior to donepezil alone, and there were statistically significant differences in several outcomes including RR in change for total effective rate (1.28, 95% confidence intervals 1.20, 1.38, p < 0.001), MD in change for Mini-Mental State Examination score (2.98, 95%CI 2.31, 3.65, p < 0.001), Barthel Index score (8.55,95%CI 1.11, 15.99, p = 0.024), Activity of Daily Living Scale (ADL)score (10.11,95% CI 7.16,13.07,p < 0.001). Conclusion: Ginkgo biloba extract combined with donepezil dramatically improved the total effective rate, MMSE, BI and ADL scores, and decreased homocysteine (HCY), plasma viscosity (PV), whole blood viscosity at high cut (BVH) and whole blood viscosity at low cut (BVL) in VaD patients, while the effect on mean flow velocity and pulse index (PI) of middle cerebral artery (MCA) is not obvious. However, more relevant high-quality RCTs are needed to validate these results. Systematic Review Registration: Identifier CRD42023474678.

Simultaneous estimation of rutin and donepezil through RP-HPLC: implication in pharmaceutical and biological samples.

Aim: A HPLC method was developed and validated for the novel combination of rutin (RN) and donepezil (DNP). Materials & methods: RN and DNP were simultaneously eluted through a C18 column (Ø 150 × 4.6 mm) with a 60:40 v/v ratio of 0.1% formic acid aqueous solution to methanol at 0.5 ml/min. Results: The purposed method was found linear, selective, reproducible, accurate and precise with percent RSD less than 2. The limit of quantification for RN and DNP was found 3.66 and 3.25 µg/ml, respectively. Conclusion: Validated as per the ICH guidelines, the developed method efficiently quantified RN and DNP co-loaded in DQAsomes (121 nm) estimating matrix effect, release profile, entrapment efficiency, loading efficiency and in vivo plasma kinetics.

[Box: see text].

Therapeutic Effect of Donepezil on Neuroinflammation and Cognitive Impairment after Moderate Traumatic Brain Injury.

BACKGROUND: Despite the important clinical issue of cognitive impairment after moderate traumatic brain injury (TBI), there is currently no suitable treatment. Here, we used in vitro and in vivo models to investigate the effect of Donepezil-an acetylcholinesterase (AChE) inhibitor-on cognitive impairment in the acute period following injury, while focusing on neuroinflammation and autophagy- and mitophagy-related markers. METHODS: The purpose of the in vitro study was to investigate potential neuroprotective effects in TBI-induced cells after donepezil treatment, and the in vivo study, the purpose was to investigate therapeutic effects on cognitive impairment in the acute period after injury by analyzing neuroinflammation and autophagy- and mitophagy-related markers. The in vitro TBI model involved injuring SH-SY5Y cells using a cell-injury controller and then investigating the effect of donepezil at a concentration of 80 µM. The in vivo TBI model was made using a stereotaxic impactor for male C57BL/6J mice. Immuno-histochemical markers and cognitive functions were compared after 7 days of donepezil treatment (1 mg/kg/day). Mice were divided into four groups: sham operation with saline treatment, sham operation with donepezil treatment, TBI with saline treatment, and TBI with donepezil treatment (18 mice in each group). Donepezil treatment was administered within 4 h post-TBI. RESULTS: In vitro, donepezil was found to lead to increased cell viability and 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimi-dazolylcarbocyanine iodide (JC-1), along with decreased reactive oxygen species (ROS), lactate-dehydrogenase (LDH), 2'-7'-dichlorodihydrofluorescein diacetate (DCFH-DA)-positive cells, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive cells. The mRNA and protein expressions of neuroinflammation (Cyclooxygenase-2, COX-2; NOD-like receptor protein 3, NLRP3; Caspase-1; and Interleukin-1 beta, IL-1ß), as well as autophagy- and mitophagy-related markers (death-associated protein kinase 1, DAPK1; PTEN-induced kinase 1, PINK1; BCL2/adenovirus E1B 19 kDa protein-interacting protein 3-like, BNIP3L; Beclin-1, BECN1; BCL2-associated X protein, BAX; microtubule-associated protein 1A/1B-light chain 3B (LC3B); Sequestosome-1; and p62) were all found to decrease after donepezil treatment. The in vivo study also showed that donepezil treatment resulted in decreased levels of cortical tissue losses and brain swelling in TBI compared to the TBI group without donepezil treatment. Donepezil treatment was also shown to decrease the mRNA and Western blotting expressions of all markers, and especially COX-2 and BNIP3L, which showed the most significant decreases. Moreover, TBI mice showed an decreased escape latency, increased alteration rate, and improved preference index, altogether pointing to better cognitive performance after donepezil treatment. CONCLUSIONS: Donepezil treatment may be beneficial in improving cognitive impairment in the early phase of moderate traumatic brain injury by ameliorating neuroinflammation, as well as autophagy and mitophagy.

Synthesis and Biological Evaluation of Colchicine─Aryl/Alkyl Amine Hybrids as Potential Noncytotoxic Cholinesterase Inhibitors: Identification of SBN-284 as a Dual Inhibitor of Cholinesterases and NLRP3 Inflammasome.

Colchicine, one of the oldest anti-inflammatory natural products still used clinically, inhibits NF-κB signaling and NLRP3 inflammasome activation. Despite its cytotoxicity and narrow therapeutic range, colchicine continues to intrigue medicinal chemists exploring its anti-inflammatory potential. This study aimed to investigate the colchicine scaffold for its role in Alzheimer's disease by targeting neuroinflammation and cholinesterases. Molecular docking revealed that colchicine's hydrophobic trimethoxyphenyl framework can potentially bind to the peripheral anionic site of cholinesterases. Hybrid structures combining colchicine with aryl/alkyl amines were designed to bind both peripheral and catalytic sites of cholinesterases. We describe here the design, synthesis, and in vitro cytotoxicity evaluation of these colchicine-aryl/alkyl amine hybrids, along with their in silico interactions with the cholinesterase active site gorge. Nontoxic analogs demonstrating strong cholinesterase binding affinity were further evaluated for their anticholinesterase and antineuroinflammatory activities. The colchicine-donepezil hybrid, SBN-284 (3x), inhibited both acetylcholinesterase and butyrylcholinesterase as well as the NLRP3 inflammasome complex at low micromolar concentrations. It achieved this through noncompetitive inhibition, occupying the active site gorge and interacting with both peripheral and catalytic anionic sites of cholinesterases. Analog 3x was shown to cross the blood-brain barrier and exhibited no toxicity to neuronal cells, primary macrophages, or epithelial fR2 cells. These findings highlight the potential of this lead compound for further preclinical investigation as a promising anti-Alzheimer agent.

Obsessive-compulsive disorder induced by donepezil in a patient with Alzheimer's disease.

Background: Donepezil, an acetylcholinesterase inhibitor commonly used to treat Alzheimer's disease (AD), is generally well tolerated. There have been no previous reports on donepezil-induced obsessive-compulsive disorder (OCD). Case Presentation: The patient, a retired man in his 70s diagnosed with AD, displayed OCD symptoms following donepezil initiation, exacerbating post-stroke-specifically, a cerebral infarction in the right posterior limb of the internal capsule. Remarkably, the symptoms abated upon discontinuation of donepezil. Conclusion: Caution should be exercised when using donepezil in patients with a history of stroke.

Computational Investigation of Novel Compounds as Dual Inhibitors of AChE and GSK-3ß for the Treatment of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease (AD) stands out as one of the most devastating and prevalent neurodegenerative disorders known today. Researchers have identified several enzymatic targets associated with AD among which Glycogen synthase kinase-3ß (GSK-3ß) and Acetylcholinesterase (AChE) are prominent ones. Unfortunately, the market offers very few drugs for treating or managing AD, and none have shown significant efficacy against it. OBJECTIVES: To address this critical issue, the design and discovery of dual inhibitors will represent a potential breakthrough in the fight against AD. In the pursuit of designing novel dual inhibitors, we explored molecular docking and dynamics analyses of tacrine and amantadine uredio-linked amide analogs such as GSK-3ß and AChE dual inhibitors for curtailing AD. Tacrine and adamantine are the FDA-approved drugs that were structurally modified to design and develop novel drug candidates that may demonstrate concurrently dual selectivity towards GSK-3ß and AChE. METHODS: In the following study, molecular docking was executed by employing AutoDock Vina, and molecular dynamics and ADMET predictions were made using Desmond, Qikprop modules of Schrödinger. RESULTS: Our findings revealed that compounds DST2 and DST11 exhibited remarkable molecular interactions with active sites of GSK-3ß and AChE, respectively. These compounds effectively interacted with key amino acids, namely Lys85, Val135, Asp200, and Phe295, resulting in highly favourable docking energies of -9.7 and -12.7 kcal/mol. Furthermore, through molecular dynamics simulations spanning a trajectory of 100 ns, we confirmed the stability of ligands DST2 and DST11 within the active cavities of GSK-3ß and AChE. The compounds exhibiting the most promising docking results also demonstrated excellent ADMET profiles. Notably, DST21 displayed an outstanding human oral absorption rate of 76.358%, surpassing the absorption rates of other molecules. CONCLUSION: Overall, our in-silico studies revealed that the designed molecules showed potential as novel anti-Alzheimer agents capable of inhibiting both GSK-3ß and AChE simultaneously. So, in the future, the designing and development of dual inhibitors will harbinger a new era of drug design in AD treatment.

Treating Diphenhydramine Overdose: A Literature Review of Currently Available Treatment Methods.

From 2019 to 2020, antihistamines were found in 15% of all US drug overdose deaths, often co-administered with fentanyl, with 3.6% of overdose deaths due to antihistamines alone. The most common antihistamine found in all these reported deaths is diphenhydramine, a ubiquitous, over-the-counter and clinically important medication. Currently, there is no antidote for diphenhydramine overdose. This review summarizes the adverse health effects and current emergency medicine treatments for diphenhydramine. Several emergency medicine case reports are reviewed, and the efficacy and outcomes of a variety of treatments are compared. The treatments reviewed include the more traditional antihistamine overdose therapeutics physostigmine and sodium bicarbonate, as well as newer ones such as donepezil, dexmedetomidine, and lipid emulsion therapy. We conclude that more study is needed to determine the ideal therapeutic approach to treating antihistamine overdoses.

Donepezil protects against cyclophosphamide-induced premature ovarian failure in mice: A focus on proinflammatory cytokines and NLRP3/TLR-4/NF-κB interplay.

BACKGROUND AND AIM: Cyclophosphamide (CP) chemotherapy is a significant iatrogenic component of premature ovarian failure (POF). The aim of this work was to evaluate the potential protective effects of donepezil, a centrally acting acetylcholinesterase (AChE) inhibitor, on CP-induced POF in mice. METHODS: 40 female Swiss albino mice were split into 5 equal groups: group 1 (control), group 2 (CP-POF); induced by intraperitoneal injection of CP on 8th day of the experiment, and group (3-5); mice received oral donepezil daily (1, 2, or 4 mg/kg, respectively) 8 days before CP injection. Mice were euthanized after 24 h of CP injection, and blood samples were collected to assay serum anti-Mullerian hormone (AMH) levels. Ovarian tissues were dissected, and the right ovary was processed for further assays of nitric oxide (NO), tumor necrosis factor-α (TNF-α), interlukin-6 (IL-6), nucleotide-binding domain-like receptor family, the Pyrin domain-containing 3 (NLRP3) inflammasome, and Toll-like receptor 4 (TLR-4), while the left one was processed for histopathological and immunohistochemical examination of nuclear factor-Kappa beta (NF-κB) and caspase-3. RESULTS: Donepezil, in a dose-dependent manner particularly (4 mg/kg), has an inhibitory action on NO (40 ± 2.85 vs. 28.20 ± 2.23, P < 0.001), proinflammatory cytokines (P < 0.001), the TLR-4/ NF-κB / NLRP3 inflammasome pathway (P < 0.001), and apoptosis (P < 0.001), with a significant elevation in the AMH levels (4.57 ± 1.08 vs. 8.57 ± 0.97, P < 0.001) versus CP-POF group. CONCLUSION: Donepezil may be a potential protective agent against CP-induced POF in mice, but further research is needed to fully understand its therapeutic function experimentally and clinically.

Design, synthesis and biological evaluation of 1-aryldonepezil analogues as anti-Alzheimer's disease agents.

Aim: To design and synthesize a novel series of 1-aryldonepezil analogues. Materials & methods: The 1-aryldonepezil analogues were synthesized through palladium/PCy3-catalyzed Suzuki reaction and were evaluated for cholinesterase inhibitory activities and neuroprotective effects. In silico docking of the most effective compound was conducted. Results: The 4-tert-butylphenyl analogue exhibited good inhibitory potency against acetylcholinesterase and butyrylcholinesterase and had a favorable neuroprotective effect on H2O2-induced SH-SY5Y cell injury. Conclusion: The 4-tert-butylphenyl derivative is a promising lead compound for anti-Alzheimer's disease drug development.

[Box: see text].

A green micelle-enhanced first derivative synchronous fluorescence approach for determination of donepezil HCl and trazodone HCl in their pure state, pharmaceutical dosage form and spiked human plasma.

The study's objective is to establish an eco-friendly, sensitive and economical quantitative methodology for the concurrent analysis of donepezil HCl (DPZ) and trazodone HCl (TRZ) in raw materials, tablets and human plasma. The first derivative synchronous fluorescence spectroscopic (FDSFS) technique was applied at constant wavelength difference (∆λ = 120) for assessment of DPZ and TRZ at each other's zero-crossing point at 279 nm and 297 nm, respectively. The submitted technique was validated in accordance with ICH Q2 R1 guidelines and the linearity of the standard calibration curve was observed over the concentration range of 10-500 ng/ml for DPZ and 20-1,000 ng/ml for TRZ. The detection limits (LOD) were found to be 2.65 and 5.4 ng/ml, and the limits of quantitation (LOQ) were 8.05 and 16.3 ng/ml for DPZ and TRZ, respectively. This technique was used further to quantify the studied medications in their laboratory-prepared mixtures, commercial tablets and spiked plasma samples. The results obtained were not significantly different from those acquired from the comparison methods, indicating the high accuracy and precision of the proposed method. Furthermore, the ecological friendliness of the suggested method was evaluated and proven to be excellent using Green Analytical Procedure Index (GAPI) and Analytical GREEnness (AGREE) evaluation tools.

Association of CHAT Gene Polymorphism rs3793790 and rs2177370 with Donepezil Response and the Risk of Alzheimer's Disease Continuum.

Background: Genetic variation plays an important role in drug response, there are few relevant studies on patients with Alzheimer's disease continuum (ADC). Objective: This study focused on the associations between two single nucleotide polymorphisms (SNPs) (rs3793790 and rs2177370) located in the CHAT gene and donepezil response in ADC patients, and further evaluated the associations between the two SNPs and ADC. Material and Methods: According to 2018 National Institute on Aging and Alzheimer's Association (NIA-AA) standard, amyloid ß-protein positive (Aß+) and negative (Aß-) patients were recruited according to the Aß-PET/CT standard. rs3793790 and rs2177370 were genotyped in buccal swab samples by using the MassARRAY system. We used the Mini Mental State Examination (MMSE) in Chinese version, caregiver evaluation, and prescribing behavior to assess therapeutic response during the 9-month period. Using logistic regression models, we analyzed the relationship between the two SNPs and donepezil response in 58 Aß+ patients treated with donepezil alone at the initial diagnosis of ADC. We also explored a probable link between the two SNPs and ADC in 147 Aß+ and 73 Aß- patients using a logistic regression analysis. Results: The chance of donepezil response was higher in patients with the G allele of rs3793790 and/or the A allele of rs2177370 than in those without (odds ratio (OR) 6.83, 95% confidence interval (CI): 1.64-28.49). Additionally, the rs3793790 variant was not associated with ADC, whereas the A allele in rs2177370 increased 1.51-fold the ADC risk (OR 2.51, 95% CI: 1.28-4.95). Conclusion: The genetic variants of rs3793790 and rs2177370 were associated with the donepezil response, and rs2177370 may have a moderate relationship with the risk of ADC.

Alzheimer's disease and its treatment-yesterday, today, and tomorrow.

Alois Alzheimer described the first patient with Alzheimer's disease (AD) in 1907 and today AD is the most frequently diagnosed of dementias. AD is a multi-factorial neurodegenerative disorder with familial, life style and comorbidity influences impacting a global population of more than 47 million with a projected escalation by 2050 to exceed 130 million. In the USA the AD demographic encompasses approximately six million individuals, expected to increase to surpass 13 million by 2050, and the antecedent phase of AD, recognized as mild cognitive impairment (MCI), involves nearly 12 million individuals. The economic outlay for the management of AD and AD-related cognitive decline is estimated at approximately 355 billion USD. In addition, the intensifying prevalence of AD cases in countries with modest to intermediate income countries further enhances the urgency for more therapeutically and cost-effective treatments and for improving the quality of life for patients and their families. This narrative review evaluates the pathophysiological basis of AD with an initial focus on the therapeutic efficacy and limitations of the existing drugs that provide symptomatic relief: acetylcholinesterase inhibitors (AChEI) donepezil, galantamine, rivastigmine, and the N-methyl-D-aspartate receptor (NMDA) receptor allosteric modulator, memantine. The hypothesis that amyloid-ß (Aß) and tau are appropriate targets for drugs and have the potential to halt the progress of AD is critically analyzed with a particular focus on clinical trial data with anti-Aß monoclonal antibodies (MABs), namely, aducanumab, lecanemab and donanemab. This review challenges the dogma that targeting Aß will benefit the majority of subjects with AD that the anti-Aß MABs are unlikely to be the "magic bullet". A comparison of the benefits and disadvantages of the different classes of drugs forms the basis for determining new directions for research and alternative drug targets that are undergoing pre-clinical and clinical assessments. In addition, we discuss and stress the importance of the treatment of the co-morbidities, including hypertension, diabetes, obesity and depression that are known to increase the risk of developing AD.

Relationship between donepezil and fracture risk in patients with dementia with Lewy bodies.

AIM: Patients with dementia with Lewy bodies (DLB) are at a high risk for falls and fractures. Although cholinesterase inhibitors reportedly are effective in suppressing the progression of cognitive symptoms in DLB patients, their effects on fracture risk remain unclarified. This study aimed to evaluate the association between donepezil use and hip fracture risk in older patients with DLB. METHODS: Using the Japanese insurance claim database, we collected the data of patients aged ≥65 years with DLB from April 2012 to March 2019. After propensity score matching, we compared the fracture rate over 3 years between DLB patients receiving donepezil and those not receiving antidementia drugs. RESULTS: Altogether, 24 022 239 individuals aged ≥65 years were newly registered from April 2012 to March 2016 and had verifiable information from 6 months before to 3 years after the registration. We identified 6634 pure-DLB patients and analyzed the data of 1182 propensity score-matched pairs. The characteristics, including age, sex, fracture history, osteoporosis, and bone mineral density test rate, of the two groups were well balanced by propensity score matching. The incidence rate of hip fracture was significantly lower in DLB patients receiving donepezil than in those not receiving antidementia drugs (0.60 vs. 1.44/100 person-years, P < 0.001), whereas that of vertebral fractures was the same. CONCLUSIONS: Donepezil administration in Japanese people aged ≥65 years with DLB was significantly associated with a decreased risk of hip fracture. Donepezil may provide new benefits to DLB patients. Geriatr Gerontol Int 2024; 24: 782-788.

Donepezil ameliorates gut barrier disruption in doxorubicin-treated rats.

An impact of donepezil against doxorubicin-induced gut barrier disruption and gut dysbiosis has never been investigated. Twenty-four male Wistar rats were divided into three groups. Each group was treated with either vehicle as a control, doxorubicin, or doxorubicin-cotreated with donepezil. Heart rate variability was assessed to reflect the impact of doxorubicin and donepezil. Then, animals were euthanized, and the ileum and its contents were collected in each case to investigate the gut barrier and gut microbiota, respectively. The microbiota-derived endotoxin, trimethylamine N-oxide (TMAO), and short-chain fatty acids (SCFAs) in the serum were determined. An increase in the sympathetic tone, endotoxins, and TMAO levels with disruption of the gut barrier and a decrease in SCFAs levels were observed in doxorubicin-treated rats. Gut microbiota of doxorubicin-treated rats was significantly different from that of the control group. Donepezil treatment significantly decreased the sympathetic tone, restored the gut barrier, and reduced endotoxin and TMAO levels in doxorubicin-treated rats. Nonetheless, donepezil administration did not alter the gut microbiota profile and levels of SCFAs in doxorubicin-treated rats. Doxorubicin impaired the autonomic balance and the gut barrier, and induced gut dysbiosis, resulting in gut toxicity. Donepezil partially improved the doxorubicin-induced gut toxicity through balancing the autonomic disturbance.

The donepezil transdermal system for the treatment of patients with mild, moderate, or severe Alzheimer's disease: a critical review.

INTRODUCTION: Cholinesterase inhibitors, along with memantine, are the mainstay of symptomatic treatment for AD (Alzheimer's disease); however, these medications are typically administered orally, which can be difficult for people with AD and their caregivers. AREAS COVERED: In this drug profile and narrative review, the authors trace the development of the new FDA-approved transdermal donepezil. The authors discuss the studies showing its bioequivalence with the oral formulation, including two double-blinded placebo controlled non-inferiority trials. The authors also compare the patch to the only other transdermal cholinesterase inhibitor on the market, rivastigmine, and highlight the potential advantages and disadvantages between these two treatments. EXPERT OPINION: While the patch is bio-equivalent, it is rather large and may not be affordable for some patients. In addition, there is no high dose (e.g. 23 mg) equivalent. Nevertheless, transdermal donepezil will be useful for people with AD and their caregivers, given its effectiveness and potential convenience.

Circadian ABCG2 Expression Influences the Brain Uptake of Donepezil across the Blood-Cerebrospinal Fluid Barrier.

Donepezil (DNPZ) is a cholinesterase inhibitor used for the management of Alzheimer's disease (AD) and is dependent on membrane transporters such as ABCG2 to actively cross brain barriers and reach its target site of action in the brain. Located in the brain ventricles, the choroid plexus (CP) forms an interface between the cerebrospinal fluid (CSF) and the bloodstream, known as the blood-CSF barrier (BCSFB). Historically, the BCSFB has received little attention as a potential pathway for drug delivery to the central nervous system (CNS). Nonetheless, this barrier is presently viewed as a dynamic transport interface that limits the traffic of molecules into and out of the CNS through the presence of membrane transporters, with parallel activity with the BBB. The localization and expression of drug transporters in brain barriers represent a huge obstacle for drug delivery to the brain and a major challenge for the development of therapeutic approaches to CNS disorders. The widespread interest in understanding how circadian clocks modulate many processes that define drug delivery in order to predict the variability in drug safety and efficacy is the next bridge to improve effective treatment. In this context, this study aims at characterizing the circadian expression of ABCG2 and DNPZ circadian transport profile using an in vitro model of the BCSFB. We found that ABCG2 displays a circadian pattern and DNPZ is transported in a circadian way across this barrier. This study will strongly impact on the capacity to modulate the BCSFB in order to control the penetration of DNPZ into the brain and improve therapeutic strategies for the treatment of AD according to the time of the day.

Evaluation of lipophilicity and drug-likeness of donepezil-like compounds using reversed-phase thin-layer chromatography.

Fourteen donepezil-like acetylcholinesterase (AChE) inhibitors from our library were analyzed using reversed-phase thin-layer chromatography to assess their lipophilicity and blood-brain barrier permeability. Compounds possessed N-benzylpiperidine and N,N-diarylpiperazine moieties connected via a short carboxamide or amine linker. Retention parameters RM 0, b, and C0 were considered as the measures of lipophilicity. Besides, logD of the investigated compounds was determined chromatographically using standard compounds with known logPow and logD values at pH 11. Experimentally obtained lipophilicity parameters correlated well with in silico generated results, and the effect of the nature of the linker between two pharmacophores and substituents on the arylpiperazine part of the molecule was observed. As a result of drug-likeness analysis, both Lipinski's rule of five and Veber's rule parameters were determined, suggesting that examined compounds could be potential candidates for further drug development. Principal component analysis was performed to obtain an insight into a grouping of compounds based on calculated structural descriptors, experimentally obtained values of lipophilicity, and AChE inhibitory activity.