Application of Intranasal Administration in the Delivery of Antidepressant Active Ingredients

Chronic, combinatorial targeting of NMDARs and 5-HT4Rs exerts extended behavioral effects against stress-induced perseverative behavior and hyponeophagia

Serotonin (5-HT) receptors and N-methyl-D-aspartate receptors (NMDARs) have both been implicated in stress-induced psychiatric disorders. However, there is a paucity of studies evaluating the effectiveness of novel combinatorial pharmacological treatments to treat stress-related disorders. Here, we evaluated whether administration of combinatorial (R,S)-ketamine, an NMDAR antagonist and Food and Drug Administration (FDA)-approved anesthetic, and prucalopride, a 5-HT type IV receptor (5-HT4R) agonist and FDA-approved drug for chronic idiopathic constipation (CIC), would have additional effects when administered after stress. A single injection of saline (Sal), (R,S)-ketamine (K), prucalopride (P), or a combined dose of (R,S)-ketamine and prucalopride (K + P) was administered for 1x, 2x, or 7x per week for 2 weeks after either contextual fear conditioning (CFC), learned helplessness (LH), stress enhanced fear learning (SEFL), or chronic corticosterone (CORT) stress in both sexes. Drug efficacy was assayed using assays to measure fear, behavioral despair, perseverative, and/or hyponeophagia. Combinatorial drug administration was also tested using intranasal delivery. We found that combinatorial K + P exerted additional effects, compared to either drug alone, in reducing a variety of stress-induced behaviors in both sexes. Moreover, intranasal dosing was also effective. Our results indicate that chronic administration of K + P has extended benefits for combating stress-induced pathophysiology. Our findings provide strong evidence that future clinical studies using this chronic treatment strategy may prove advantageous in decreasing a broad range of stress-induced psychiatric disorders.

Intranasal delivery of kaempferol via magnesomes for brain seizure treatment: Design, characterization, and biodistribution studies

The current study aims to develop phospholipid magnesomes retaining the inherent neuroprotective activities of kaempferol as a proposed treatment approach for epilepsy. Magnesomes were prepared using varied amounts of phospholipid, magnesium sulfate and poloxamer 188, and evaluated on in-vitro and in-vivo levels. The prepared vesicles possessed nanosizes (112-625 nm), negative charges (-16 to -20 mV), and entrapment efficiency (80-96 %) with negligible changes in their colloidal properties after 3 months' storage. Magnesomes showed sustained release of kaempferol as well as superior permeability relative to drug solution. Radiolabeling of kaempferol with iodine-131 was successfully performed using electrophilic substitution. The superior brain uptake of intranasally delivered 131I-kaempferol-magnesomes containing 3.13 µg/20µl of kaempferol compared to intravenous and intranasal solutions was demonstrated employing biodistribution and pharmacokinetic tests conducted using Swiss Albino male mice. Brain to blood ratio of the intranasally administered kaempferol was significantly higher compared to intravenous injection showing uptake of 9.9 ± 0.3 % injected dose per gram organ at the first 5 min ensuring a rapid onset of action. The drug targeting efficiency and nose to brain direct transport percentages of 131I- kaempferol-magnesomes were 215.0 and 87.0 %, respectively with relative bioavailability of 810.24 ± 119.1 %. Accordingly, intranasal kaempferol-magnesomes showed effectiveness in brain targeting and could be beneficial for managing epileptic seizures.

Significantly Increased Aqueous Solubility of Piperine via Nanoparticle Formulation Serves as the Most Critical Factor for Its Brain Uptake Enhancement

Introduction

Piperine, the major component in Piper retrofractum and Piper nigrum, had potential therapeutic effects on central nervous system diseases such as Alzheimer's disease, Parkinson's disease, epilepsy and fragile X-associated tremor/ataxia syndrome. However, its low aqueous solubility (0.04 mg/mL) limits brain uptake and pharmacological investigations at higher doses. In the current study, formulation strategies and routes of administration were assessed to enhance systemic and brain uptake of piperine.

Methods

Formulation of piperine nanoparticles (PIP NPs) was developed to enhance its solubility. PIP NPs were prepared using flash nanoprecipitation via a four-stream Multi-Inlet Vortex Mixer, employing an aqueous solution of poloxamer 188 and an ethanolic solution containing piperine and Eudragit L100-55. The process was optimized using the Design of Experiments to minimize the particle size and maximize the encapsulation efficiency of piperine. Additionally, we investigated the impact of administrating PIP NPs via oral and intranasal routes on its systemic and brain uptake.

Results

The optimized PIP NPs formulation exhibited a particle size of 171.45±2.38 nm, polydispersity index of 0.27±0.01, zeta potential of -43.71±5.11 mV, encapsulation efficiency of 92.49±1.92% and drug loading of 15.07±0.09%. Fourier-transform infrared spectroscopy confirmed the successful encapsulation of piperine into nanoparticles. The PIP NPs could significantly increase the aqueous solubility of piperine from 0.04 mg/mL to 52.31±0.9 mg/mL and release piperine with a 12.83-fold higher rate than that from piperine suspension. Both oral and intranasal administrations of PIP NPs to C57BL/6 mice at 20 mg/kg demonstrated an increase in AUC0-120min for both plasma (7.9-10 times) and brain (4.7-5.0 times) comparing to that from piperine suspension, with no significant difference between these two routes.

Discussion

Our findings suggested that increasing solubility rather than changing the administration route served as the most critical step to enhance the brain uptake of piperine.

Escitalopram oxalate-loaded chitosan nanoparticle in situ gel formulation intended for direct nose-to-brain delivery: in vitro, ex vivo, and in vivo pharmacokinetic evaluation

Introduction: Escitalopram oxalate (ESCI) is a biopharmaceutical classification system (BCS) class II antidepressant drug, that suffers limited oral bioavailability due to extensive hepatic metabolism. Therefore, this study aimed to develop and evaluate chitosan nanoparticles (CSNPs) embedded in an in situ gel for intranasal (i.n) drug delivery. Methods: ESCl-loaded CSNPs were prepared by the ionic gelation method and were optimized using 32 factorial design. The optimized CSNPs were incorporated into pH-sensitive in situ gel composed of carbopol 940 and HPMC K4M for i. n administration. Results: The optimized CSNPs exhibited a particle size of 189 ± 3.14 nm, polydispersity index 0.372 ± 0.84, zeta potential 22.2 ± 1.25 mV, and entrapment efficiency of 76.5% ± 1.64%. FTIR, DSC, and XRD analysis of CSNPs confirmed the encapsulation of the ESCI within the formulation. The in vitro drug release profile of the ESCI-loaded CSNPs in situ gel exhibited an initial burst release followed by a slow and sustained release phase. The in situ gel studies demonstrated that 80.72% ± 3.12% of the drug permeated within 8 h through the goat nasal mucosa in ex vivo permeation studies. In pharmacokinetic studies, the Cmax in the brain following a single nasal administration of ESCI-loaded CSNPs in situ gel was 4.67 folds higher than the oral solution. The total AUC0-12 in situ gel was 3.40 times higher than the i. n drug solution and 13.31 times higher than an oral solution. The mean residence time (MRT) for the brain's CSNPs in situ gel was higher than i. n drug and oral solutions. Conclusion: This higher Cmax and prolonged MRT in the brain highlight the potential of CSNPs in situ gel as an effective brain-targeting system via the intranasal route. These results indicate that i. n delivery of the ESCl-loaded CSNPs in situ gel is a promising strategy for controlled release of ESCI, enhancing therapeutic efficacy and mitigating the disadvantages of oral delivery.

Cyclodextrin-Based Drug Delivery Systems for Depression: Improving Antidepressant Bioavailability and Targeted Central Nervous System Delivery

Cyclodextrin (CD)-based drug delivery systems have emerged as a promising strategy to overcome limitations commonly encountered in antidepressant therapy, including low bioavailability, poor solubility, and suboptimal penetration of the blood-brain barrier. This review synthesizes current evidence demonstrating that complexing various classes of antidepressants-such as tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), and atypical antidepressants-with β-CD or its derivatives significantly enhances drug solubility and stability. In addition, encapsulation with CDs can diminish systemic toxicity and improve pharmacokinetics, thereby helping to optimize dosage regimens and reduce adverse effects. Analysis of published in vitro and in vivo studies indicates that CD formulations not only boost therapeutic efficacy but also enable sustained or targeted release, which is critical for drugs requiring precise plasma and tissue concentrations. When compared to other carriers (e.g., liposomes, polymeric nanoparticles, dendrimers), CD-based systems often stand out for their ease of formulation, biocompatibility, and cost-effectiveness, although limited drug-loading capacity can be a drawback. We recommend expanding in vivo trials to substantiate the clinical benefits of CD-antidepressant complexes, particularly for treatment-resistant cases or specific subpopulations (e.g., elderly and pediatric patients). Additional investigations should also explore hybrid systems-combining CDs with advanced nano- or macroparticles-to amplify their advantages and address any limitations. Ultimately, integrating CDs into antidepressant regimens holds substantial potential to refine therapy outcomes, reduce adverse events, and pave the way for more personalized, effective interventions for depression.

An Approach to Enhance the Solubility of an Atypical Antipsychotic Drug, Aripiprazole: Design, Characterization, and Evaluation of Arabinoxylan-Based Nanoparticles

Introduction

Natural polymers have emerged as versatile and sustainable alternatives to synthetic polymers in pharmaceutical and biomedical applications. This study focuses on the extraction of arabinoxylan (AX) from maize husk and its potential as a promising excipient to enhance the solubility and oral bioavailability of Aripiprazole (APZ), a poorly water-soluble antipsychotic drug, offering a robust strategy for overcoming challenges associated with hydrophobic drugs.

Methods

APZ-loaded AX nanoparticles were synthesized using the ionotropic gelation technique. The formulation with the highest encapsulation efficiency designated as FN4 was selected for detailed characterization. Various analytical techniques, including Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Differential Scanning Calorimetry (DSC), were employed to assess the morphological, crystalline, and thermal properties of the nanoparticles. In vitro release studies were conducted on both simulated gastric fluid (pH 1.2) and simulated intestinal fluid (pH 6.8) to evaluate drug dissolution behaviour. The everted sac method was utilized to assess the permeation and transport of APZ from the AX-based nanoparticles.

Results

The FN4 formulation exhibited an encapsulation efficiency of 88.9% ± 1.77%, with a particle size of 284.4 nm, a polydispersity index (PDI) of 0.346, and a zeta potential of 20.7 mV. SEM analysis revealed a uniform distribution of polyhedral-shaped nanoparticles. XRD and DSC analyses indicated that APZ was in an amorphous state within the nanoparticles. Drug release was more pronounced at pH 6.8, with the AX nanoparticles showing sustained release. The everted sac method demonstrated enhanced permeation of APZ across intestinal membranes, supporting the potential of AX nanoparticles in improving drug absorption.

Discussion

The AX-based nanoparticle formulation significantly improved the solubility, pH-dependent release profile, and sustained release of APZ, offering a promising strategy to enhance the oral bioavailability of poorly soluble drugs. These findings suggest that AX nanoparticles could serve as an effective delivery system for enhancing the therapeutic potential of hydrophobic drugs like APZ.

Advancement in the Nose-to-Brain Drug delivery of FDA-approved drugs for the better management of Depression and Psychiatric disorders

The Prevalence of Depressive and Psychiatric disorders is increasing globally, and despite the availability of numerous FDA-approved drugs, treatment remains challenging. Many conventional antidepressants and antipsychotic formulations face issues such as low solubility, high first-pass metabolism, poor bioavailability, inadequate blood-brain barrier penetration, and systemic side effects. These challenges lead to reduced efficacy, slower onset of action, and decreased patient adherence to treatment. To address these problems, recent studies have explored the nose-to-brain route for drug delivery. This method offers several advantages, including non-invasive drug administration, direct access to the brain, rapid onset of action, reduced systemic exposure and side effects, avoidance of first-pass metabolism, enhanced bioavailability, precision dosing, and improved patient compliance. The formulations used for this approach include lipidic nanoparticles, polymeric nanoparticles, nasal gels, cubosomes, niosomes, polymeric micelles, nanosuspensions, nanoemulsions, nanocapsules, and elastosomes. This review analyzes and summarizes the published work on the nose-to-brain delivery of FDA-approved antidepressants and antipsychotic drugs, with a focus on the preparation, characterization, pharmacokinetics, pharmacodynamics, and toxicity profiling of these nanoformulations.

Dihydroquercetin nanoparticles nasal gel is a promising formulation for amelioration of Alzheimer's disease

Dihydroquercetin is a natural flavonoid with anti-inflammatory, antioxidant, and neuroprotective activities. Dihydroquercetin exhibits a great neuroprotector promise in Alzheimer's disorder via preventing the aggregation of amyloid-beta-peptide-Aβ(1-42). The goal of the study was to create dihydroquercetin-loaded-chitosan nanoparticles (DHQ-CS NPs) loaded to a mucoadhesive, thermosensitive in-situ gel for direct nasal administration to cure Alzheimer's disorder. Loading drug in chitosan nanoparticles and incorporation into thermosensitive gel enhanced residence time and reduced mucociliary-clearance. Different in-vitro-physicochemical-characteristics of gels and nanoparticles-characterization were used to evaluate the formulations. The therapeutic effectiveness of DHQ-CS NPs gel was evaluated behaviorally, biochemically and histopathologically in Alzheimer's-rat-model compared to intranasal DHQ gel. The small particles-size was obtained = 235.3 nm of DHQ-CS NPs. The DHQ-CS NPs gel demonstrated a greater release rate compared to the raw DHQ gel. Additionally, the nasal-administration of the DHQ-CS NPs gel showed better In-vivo results compared to DHQ gel, through improvement of memory and learning deficits and also the exploratory behavior and new object memory in streptozotocin induced-Alzheimer rats. Biochemically, the intranasal DHQ-CS NPs gel, showed reduced both Aβ-protein formation and tau protein hyperphosphorylation, inhibition of acetylcholine esterase activity and oxidative stress in the brain with increase of total antioxidants in the brain and serum, compared to DHQ gel. Histopathologically, the DHQ-CS NPs nasal gel produced improvement in the hippocampal and cerebral cortex structures, being comparable to the normal group. Consequently, the intranasal DHQ-CS NPs loaded in-situ gel seems to be a promising therapeutic formulation for Alzheimer's disease medication.

Non-Invasive Techniques of Nose to Brain Delivery Using Nanoparticulate Carriers: Hopes and Hurdles

Intranasal drug delivery route has emerged as a promising non-invasive method of administering drugs directly to the brain, bypassing the blood-brain barrier (BBB) and blood-cerebrospinal fluid barriers (BCSF). BBB and BCSF prevent many therapeutic molecules from entering the brain. Intranasal drug delivery can transport drugs from the nasal mucosa to the brain, to treat a variety of Central nervous system (CNS) diseases. Intranasal drug delivery provides advantages over invasive drug delivery techniques such as intrathecal or intraparenchymal which can cause infection. Many strategies, including nanocarriers liposomes, solid-lipid NPs, nano-emulsion, nanostructured lipid carriers, dendrimers, exosomes, metal NPs, nano micelles, and quantum dots, are effective in nose-to-brain drug transport. However, the biggest obstacles to the nose-to-brain delivery of drugs include mucociliary clearance, poor drug retention, enzymatic degradation, poor permeability, bioavailability, and naso-mucosal toxicity. The current review aims to compile current approaches for drug delivery to the CNS via the nose, focusing on nanotherapeutics and nasal devices. Along with a brief overview of the related pathways or mechanisms, it also covers the advantages of nasal drug delivery as a potential method of drug administration. It also offers several possibilities to improve drug penetration across the nasal barrier. This article overviews various in-vitro, ex-vivo, and in-vivo techniques to assess drug transport from the nasal epithelium into the brain.

Fabrication of Uniform Melatonin Microparticles Potentially for Nasal Delivery: A Comparison of Spray Drying and Spray Freeze Drying

PURPOSE

Insomnia is a major health concern, and melatonin (MLT) is key for initiating sleep. Delivering MLT nasally can enhance brain bioavailability by targeting the olfactory region. This study aimed to fabricate MLT embedded microparticles for nasal delivery.

METHODS

MLT-cyclodextrin (CD) derivatives complex microparticles (MCCMPs) were fabricated by spray drying and spray freeze drying MLT and CD derivative solutions. Phase solubility and 1H-1H ROSEY NMR analysis assessed MLT-CD assembly. The effects of formulation compositions and process parameters on microparticle structural attributes were investigated. The in vitro nasal release and deposition performances were evaluated by a modified paddle-over-disk apparatus and 3D-printed nasal cavity cast, respectively.

RESULTS

Sodium sulphobutylether-β-cyclodextrin (SBE-β-CD) exhibited the best complexation ability with MLT, with the indole structure of MLT included in its cavity. Spray dried MCCMPs showed dense structure with high density, while the spray freeze dried counterpart showed the brittle and porous structure with low density. Despite the porous structure may promote the release rate of spray freeze dried samples, the high hydrophilicity of the CD derivative overshadows this advantage. Samples prepared by spray drying not only exhibited rapid release rates but also could deposit more effectively in the olfactory region, as they avoid breakage due to their higher mechanical strength. The optimal sample showed ~ 86.70% of the MLT released at 20 min and ~ 10.57% of the deposition fraction in the olfactory region.

CONCLUSIONS

This work compares MCCMPs fabricated by spray drying and spray freeze drying, providing the optimal formulation and process combinations.

Emerging Perspectives on Prime Editor Delivery to the Brain

Prime editing shows potential as a precision genome editing technology, as well as the potential to advance the development of next-generation nanomedicine for addressing neurological disorders. However, turning in prime editors (PEs), which are macromolecular complexes composed of CRISPR/Cas9 nickase fused with a reverse transcriptase and a prime editing guide RNA (pegRNA), to the brain remains a considerable challenge due to physiological obstacles, including the blood-brain barrier (BBB). This review article offers an up-to-date overview and perspective on the latest technologies and strategies for the precision delivery of PEs to the brain and passage through blood barriers. Furthermore, it delves into the scientific significance and possible therapeutic applications of prime editing in conditions related to neurological diseases. It is targeted at clinicians and clinical researchers working on advancing precision nanomedicine for neuropathologies.

In-depth Mechanism, Challenges, and Opportunities of Delivering Therapeutics in Brain Using Intranasal Route

Central nervous system-related disorders have become a continuing threat to human life and the current statistic indicates an increasing trend of such disorders worldwide. The primary therapeutic challenge, despite the availability of therapies for these disorders, is to sustain the drug's effective concentration in the brain while limiting its accumulation in non-targeted areas. This is attributed to the presence of the blood-brain barrier and first-pass metabolism which limits the transportation of drugs to the brain irrespective of popular and conventional routes of drug administration. Therefore, there is a demand to practice alternative routes for predictable drug delivery using advanced drug delivery carriers to overcome the said obstacles. Recent research attracted attention to intranasal-to-brain drug delivery for promising targeting therapeutics in the brain. This review emphasizes the mechanisms to deliver therapeutics via different pathways for nose-to-brain drug delivery with recent advancements in delivery and formulation aspects. Concurrently, for the benefit of future studies, the difficulties in administering medications by intranasal pathway have also been highlighted.

Intranasal delivery of herbal medicine for disease treatment: A systematic review

BACKGROUND

Intranasal administration has been adopted in traditional medicine to facilitate access to the bloodstream and central nervous system (CNS). In modern medicine, nasal drug delivery systems are valuable for disease treatment because of their noninvasiveness, good absorption, and fast-acting effects.

OBJECTIVE

This study aimed to systematically organize preclinical and clinical studies on intranasal herbal medicines to highlight their potential in drug development.

METHODS

A comprehensive search for literature until February 2023 was conducted on PubMed and the Web of Science. From the selected publications, we extracted key information, including the types of herbal materials, target diseases, intranasal conditions, methods of toxicity evaluation, main outcomes, and mechanisms of action, and performed quality assessments for each study.

RESULTS

Of the 45 studies, 13 were clinical and 32 were preclinical; 28 studies used herbal extracts, 9 used prescriptions, and 8 used natural compounds. The target diseases were rhinosinusitis, influenza, fever, stroke, migraine, insomnia, depression, memory disorders, and lung cancer. The common intranasal volumes were 8-50 µl in mice, 20-100 µl in rats, and 100-500 µl in rabbits. Peppermint oil, Ribes nigrum folium, Melia azedarach L., Elaeocarpus sylvestris, Radix Bupleuri, Da Chuan Xiong Fang, Xingnaojing microemulsion, and Ginsenoside Rb1 emerged as potential candidates for rapid intranasal therapy. The in vivo toxicity assessments were based on mortality, body weight, behavioral changes, mucociliary activity, histopathology, and blood tests. Most intranasal treatments were safe, except for Cyclamen europaeum, Jasminum sambac, Punica granatum L., and violet oil, which caused mild adverse effects. At lower doses, intranasal herbal treatments often show greater effects than oral administration. The actions of intranasal herbal medicine mainly involve regulating inflammation and neurotransmission, with the olfactory bulb and anterior cingulate cortex to be relevant brain regions.

CONCLUSION

Intranasal delivery of herbal materials holds promise for enhancing drug delivery efficacy and reducing treatment duration, offering a potential future perspective for developing intranasal therapies for various diseases.

Potentiation of antidepressant effects: NPY1R agonist and ketamine synergy enhances TrkB signaling and neurogenesis in the ventral hippocampus

BACKGROUND

Major Depressive Disorder (MDD) poses a significant challenge to global health, with current treatments often limited by efficacy and onset delays. This study explores the synergistic antidepressant-like effects of an NPY1R agonist and Ketamine, targeting their neurobiological interactions within the ventral hippocampus.

RESEARCH DESIGN AND METHODS

Utilizing a preclinical model, this study administered Neuropeptide Y receptor 1 (NPY1R) agonist and Ketamine, both separately and in combination, through intracerebroventricular (icv) and intranasal (i.n.) routes. The Forced Swimming Test (FST) was employed to assess antidepressant-like activity, while in situ Proximity Ligation Assay and immunohistochemistry were used to examine NPY1R/TrkB heteroreceptor complexes and BDNF expression in the ventral dentate gyrus (DG), along with neurogenesis markers.

RESULTS

The combined treatment significantly reduced immobility in the FST, indicative of enhanced antidepressant-like effects, correlated with increased formation of NPY1R/TrkB complex and brain-derived neurotrophic factor (BDNF) expression in the ventral DG. These molecular alterations were associated with increased neurogenesis.

CONCLUSIONS

The coadministration of an NPY1R agonist and Ketamine in a rodent model demonstrated potentiated antidepressant responses through synergistic neurobiological pathways, including TrkB signaling and hippocampal neurogenesis. This indicates a novel therapeutic strategy for MDD, warranting further clinical investigation to fully understand its implications.

Nose-to-brain delivery of nanotherapeutics: Transport mechanisms and applications

The blood-brain barrier presents a key limitation to the administration of therapeutic molecules for the treatment of brain disease. While drugs administered orally or intravenously must cross this barrier to reach brain targets, the unique anatomical structure of the olfactory system provides a route to deliver drugs directly to the brain. Entering the brain via receptor, carrier, and adsorption-mediated transcytosis in the nasal olfactory and trigeminal regions has the potential to increase drug delivery. In this review, we introduce the physiological and anatomical structures of the nasal cavity, and summarize the possible modes of transport and the relevant receptors and carriers in the nose-to-brain pathway. Additionally, we provide examples of nanotherapeutics developed for intranasal drug delivery to the brain. Further development of nanoparticles that can be applied to intranasal delivery systems promises to improve drug efficacy and reduce drug resistance and adverse effects by increasing molecular access to the brain. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease.

Past, present, and future of deep transcranial magnetic stimulation: A review in psychiatric and neurological disorders

Deep transcranial magnetic stimulation (DTMS) is a new non-invasive neuromodulation technique based on repetitive transcranial magnetic stimulation tech-nology. The new H-coil has significant advantages in the treatment and mechanism research of psychiatric and neurological disorders. This is due to its deep stimulation site and wide range of action. This paper reviews the clinical progress of DTMS in psychiatric and neurological disorders such as Parkinson's disease, Alzheimer's disease, post-stroke motor dysfunction, aphasia, and other neurological disorders, as well as anxiety, depression, and schizophrenia.

Microbes, oxytocin and stress: Converging players regulating eating behavior

Oxytocin is a peptide-hormone extensively studied for its multifaceted biological functions and has recently gained attention for its role in eating behavior, through its action as an anorexigenic neuropeptide. Moreover, the gut microbiota is involved in oxytocinergic signaling through the brain-gut axis, specifically in the regulation of social behavior. The gut microbiota is also implicated in appetite regulation and is postulated to play a role in central regulation of hedonic eating. In this review, we provide an overview on oxytocin and its individual links with the microbiome, the homeostatic and non-homeostatic regulation of eating behavior as well as social behavior and stress.

Nasal-PAMPA: A novel non-cell-based high throughput screening assay for prediction of nasal drug permeability

In nasal drug product development, screening studies are vital to select promising compounds or formulations. The Parallel Artificial Membrane Permeability Assay (PAMPA), a high throughput screening tool, has been applied to evaluate drug permeability across several barriers such as the skin or blood-brain barrier. Herein, a new nasal-PAMPA model was optimized to predict nasal permeability, using a biorelevant donor medium containing mucin. The apparent permeability (Papp) of 15 reference compounds was assessed in six different experimental conditions, and the most discriminating and predictive model was applied to a test drug (piroxicam) and mucoadhesive powder formulations loading the same drug. The model with 0.5% (w/v) mucin in the donor compartment and 2% (w/v) phosphatidylcholine in the lipid membrane accurately distinguished high and low permeable compounds. Additionally, it exhibited the highest correlation with permeation across human nasal epithelial cells, RPMI 2650 (R2 = 0.93). When applied to powder formulations, this model was sensitive to the presence of mucoadhesive excipients and the drug solid state. Overall, the nasal-PAMPA model was more rapid than cell-based assays, without requiring specialized training or equipment, showing to be a promising in vitro tool that can be applied in drug and formulation screening for nasal delivery.

Screening for Neuroprotective and Rapid Antidepressant-like Effects of 20 Essential Oils

Depression is a serious psychiatric disorder with high prevalence, and the delayed onset of antidepressant effects remains a limitation in the treatment of depression. This study aimed to screen essential oils that have the potential for rapid-acting antidepressant development. PC12 and BV2 cells were used to identify essential oils with neuroprotective effects at doses of 0.1 and 1 µg/mL. The resulting candidates were treated intranasally (25 mg/kg) to ICR mice, followed by a tail suspension test (TST) and an elevated plus maze (EPM) after 30 min. In each effective essential oil, five main compounds were computationally analyzed, targeting glutamate receptor subunits. As a result, 19 essential oils significantly abolished corticosterone (CORT)-induced cell death and lactate dehydrogenase (LDH) leakage, and 13 reduced lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6). From in vivo experiments, six essential oils decreased the immobility time of mice in the TST, in which Chrysanthemum morifolium Ramat. and Myristica fragrans Houtt. also increased time and entries into the open arms of the EPM. Four compounds including atractylon, α-curcumene, α-farnesene, and selina-4(14),7(11)-dien-8-one had an affinity toward GluN1, GluN2B, and Glu2A receptor subunits surpassed that of the reference compound ketamine. Overall, Atractylodes lancea (Thunb.) DC and Chrysanthemum morifolium Ramat essential oils are worthy of further research for fast-acting antidepressants through interactions with glutamate receptors, and their main compounds (atractylon, α-curcumene, α-farnesene, and selina-4(14),7(11)-dien-8-one) are predicted to underlie the fast-acting effect.

Recent Advances in Intranasal Liposomes for Drug, Gene, and Vaccine Delivery

Liposomes are safe, biocompatible, and biodegradable spherical nanosized vesicles produced from cholesterol and phospholipids. Recently, liposomes have been widely administered intranasally for systemic and brain delivery. From the nasal cavity, liposome-encapsulated drugs and genes enter the systemic circulation primarily via absorption in the respiratory region, whereas they can be directly transported to the brain via the olfactory pathway. Liposomes can protect drugs and genes from enzymatic degradation, increase drug absorption across the nasal epithelium, and prolong the residence time in the nasal cavity. Intranasal liposomes are also a potential approach for vaccine delivery. Liposomes can be used as a platform to load antigens and as vaccine adjuvants to induce a robust immune response. With the recent interest in intranasal liposome formulations, this review discusses various aspects of liposomes that make them suitable for intranasal administration. We have summarized the latest advancements and applications of liposomes and evaluated their performance in the systemic and brain delivery of drugs and genes administered intranasally. We have also reviewed recent advances in intranasal liposome vaccine development and proposed perspectives on the future of intranasal liposomes.