Nasal formulations for drug administration and characterization of nasal preparations in drug delivery

Simvastatin is delivered to the brain by high-strength intranasal cationic SMEDDS and nanoemulsions

The repurposing of statins as neuroprotective agents and/or anti-brain tumor drugs is limited by challenges in brain bioavailability and systemic off-target effects. Therefore, improved and targeted delivery of statins to the brain is necessary. This study aimed to develop a high-strength liquid formulation of the poorly soluble prodrug simvastatin for intranasal administration, as a strategy to achieve high brain concentrations of the prodrug and/or its active form, tenivastatin. Cationic simvastatin nanoemulsions (c-NE) and self-microemulsifying drug delivery systems (c-SMEDDS) were screened for composition, extensively characterized, and the viscosity of the nanoemulsion was further optimized. The optimized c-NE and c-SMEDDS formulations achieved high drug strengths, approximately 5.5% and 9% (w/w), respectively. They formed highly homogeneous aqueous dispersions (polydispersity index < 0.1) with small droplet sizes (< 120 nm and ~ 25 nm, respectively) and remained stable for at least four months under refrigeration. Neither the c-NE nor the c-SMEDDS induced hemolysis up to concentrations of 40 µg/mL and 450 µg/mL of simvastatin, respectively. The zero-shear viscosity of the c-NE was increased to 186 mPa·s by incorporating 0.25% (w/w) polyvinylpyrrolidone, which approached the viscosity of the c-SMEDDS (~ 126 mPa·s). Following intranasal administration of the optimized formulations to Wistar rats at a dose of 10 mg/kg, simvastatin levels in the brain reached 50 to 150 ng/g between 15 and 60 min post-administration. These findings indicate that the developed c-NE and c-SMEDDS formulations hold promise for simvastatin intranasal delivery and brain targeting, potentially paving the way for the realization of simvastatin's neuroprotective potential.

Development of Nanocomposite Microspheres for Nasal Administration of Deferiprone in Neurodegenerative Disorders

Elevated brain iron levels are characteristic of many neurodegenerative diseases. As an iron chelator with short biological half-life, deferiprone leads to agranulocytosis and neutropenia with a prolonged therapeutic course. Its inclusion in sustained-release dosage forms may reduce the frequency of administration. On the other hand, when administered by an alternative route of administration, such as the nasal route, systemic exposure to deferiprone will be reduced, thereby reducing the occurrence of adverse effects. Direct nose-to-brain delivery has been raised as a non-invasive strategy to deliver drugs to the brain, bypassing the blood-brain barrier. The aim of the study was to develop and characterize nanocomposite microspheres suitable for intranasal administration by combining nano- and microparticle-based approaches. Nanoparticles with an average particle size of 213 ± 56 nm based on the biodegradable polymer poly-ε-caprolactone were developed using the solvent evaporation method. To ensure the deposition of the particles in the nasal cavity and avoid exhalation or deposition into the small airways, the nanoparticles were incorporated into composite structures of sodium alginate obtained by spray drying. Deferiprone demonstrated sustained release from the nanocomposite microspheres and high iron-chelating activity.

Mucoadhesive in situ nasal gel of amoxicillin trihydrate for improved local delivery: Ex vivo mucosal permeation and retention studies

Orally administered amoxicillin is recommended as the first-line treatment of acute bacterial rhinosinusitis (ABR) and given in a high-dose regimen. However, the risk of various systemic adverse reactions and low oral bioavailability are unbearable, increasing the threat of antibiotic resistance. Therefore, nasal delivery of amoxicillin can be a potential approach for effectively treating ABR locally, as well as overcoming those drawbacks. In a way to guarantee the effectiveness for local therapy in nasal cavity, the permeation and retention properties are of significant importance considerations. Accordingly, the present work aimed to investigate the characteristics with respect to the nasal applicability of the in situ gelling amoxicillin trihydrate (AMT) and further evaluate its permeability and retention properties through human nasal mucosa. The lyophilized formulations were characterized utilizing the Differential Scanning Calorimetry (DSC) and X-ray Powder Diffraction (XRPD), and also evaluated for its polarity, reconstitution time, droplet size distribution, mucoadhesive properties, and ex vivo permeability and retention studies. The results confirmed that the in situ gelling AMT formulations possess adequate mucoadhesive behavior, especially the formulation containing 0.3 % of gellan gum. Substantially, the in situ gelling AMT formulations were able to retain the drug on the surface of nasal mucosa instead of permeating across the membrane; thus, suitable for treating nasal infections locally. Altogether, the in situ gelling systems demonstrates promising abilities as a delivery platform to enhance local application of AMT within the nasal cavity.

Technological Strategies Applied to Pharmaceutical Systems for Intranasal Administration of Drugs Intended for Neurological Treatments: A Review

The complexity of treating neurological diseases has meant that new strategies have had to be developed to deliver drugs to the brain more efficiently and safely. Intranasal drug delivery is characterized by its ease of administration, safety, and rapid delivery directly from the nose to the brain. Several strategies have been developed to improve the delivery of drugs to the brain via nasal administration. These include the use of mucoadhesive and thermoresponsive polymers and their combination into polymer blends, as well as the use of liposomes, niosomes, and nano- and microemulsions. Therefore, this review focuses on technologies for developing pharmaceutical systems aimed at delivery via the nose to the brain, contributing to new treatments for difficult neurological disorders. Some of the most common and difficult-to-treat neurological conditions, the intranasal route of administration, and the anatomy of the nasal cavity have been discussed, as well as factors that may influence the absorption of drugs administered into the nose. The types of intranasal formulations and the devices that can be used to administer these products are also discussed in this review. Strategies for improving the transport of bioactive agents and increasing bioavailability are highlighted. The technologies discussed in this review can facilitate the development of formulations with improved properties, such as drug release and mucoadhesiveness, which have several advantages for patients requiring complex neurological treatments.

Serum Albumin in Nasal Drug Delivery Systems: Exploring the Role and Application

The application of serum albumin in various types of formulations has emerged as a valuable option in biomedical research, especially in the field of nasal drug delivery systems. A serum albumin-based carrier system has been employed due to several benefits, such as enhancing drug solubility and stability, generating the desired controlled release profile, and developing favorable properties with respect to the challenges in nasal conditions, which, in this case, involves hindering rapid elimination due to nasal mucociliary clearance. Accordingly, considering the important role of serum albumin, in-depth knowledge related to its utilization in preparing nasal drug formulation is highly encouraged. This review aimed to explore the potential application of serum albumin in fabricating nasal drug formulations and its crucial role and functionality regarding the binding interaction with nasal mucin, which significantly determines the successful administration of nasal drug formulations.

A thermosensitive chitosan hydrogel: An attempt for the nasal delivery of dimethyl fumarate

Dimethyl fumarate (DMF) is a drug that is orally administered for the treatment of relapsing-remitting multiple sclerosis. However, DMF causes gastrointestinal side effects and flushing in 43 % of patients, which significantly contributes to treatment discontinuation. To reduce side effects and increase patient compliance, the aim of this study was to develop a thermosensitive chitosan/glycerophosphate hydrogel for the nasal administration of DMF. A binary system of DMF with hydroxypropyl-β-cyclodextrin (HP-β-CD) was made and included in the hydrogel precursor solution. The precursor solution (drug content, DMF stability, thermogelling properties, viscosity), and the resulting thermosensitive hydrogel (mucoadhesion, in vitro DMF permeation) were characterized. HP-β-CD was able to interact with DMF and improve its water solubility. The leader thermosensitive nasal solution, G1 solution, was loaded with approximately 92 % DMF, which remained stable for 21 days. The G1 solution formed a hydrogel in approximately 2-1 min; it had a pH of 6.8 ± 0.06 and caused no significant change in the osmolality of the simulated nasal medium. The G1 hydrogel showed good mucoadhesive properties and released DMF that permeated in vitro in a controlled manner. As a result, G1 is a potential new approach to exploit the intranasal administration of DMF for treating multiple sclerosis.

Clinically Relevant Characterization and Comparison of Ryaltris and Other Anti-Allergic Nasal Sprays

The deposition, residence time, and dissolution profile of nasal suspensions containing corticosteroids play a key role in their in vivo efficacy after administration. However, the conventional methods available to characterize nasal products appear to be unsuitable to exhaustively cover these aspects. The work aims to investigate technological aspects of Ryaltris (mometasone furoate and olopatadine hydrochloride nasal spray) compared to other commercial anti-allergic nasal products, namely, Dymista (azelastine hydrochloride and fluticasone propionate), Nasonex (mometasone furoate), and Avamys (fluticasone furoate). Innovative characterization methods were combined with more traditional approaches to investigate the anti-allergic nasal sprays. These methods applied together allowed to differentiate between the different products and provided a clear picture of the nasal product behavior in terms of drug dissolution and deposition. In particular, the dissolution tests were performed exploiting the Respicell® apparatus, an innovative technique that allows for the investigation of inhalation products. Then, formulation viscosities were considered along with a formulation flow test on an inclined plane. Finally, the intranasal deposition profile of the commercial formulations was determined using a silicon nasal cast. The results highlight in vitro significant differences in terms of viscosity as well as dissolution rate of the nasal products, with Ryaltris showing a higher viscosity and lower flow compared to other products, which, along with a corticosteroid faster dissolution rate than Dymista, suggest a potential advantage in terms of clinical behavior.

Curcumin and quercetin co-encapsulated in nanoemulsions for nasal administration: A promising therapeutic and prophylactic treatment for viral respiratory infections

One of the most frequent causes of respiratory infections are viruses. Viruses reaching the airways can be absorbed by the human body through the respiratory mucosa and mainly infect lung cells. Several viral infections are not yet curable, such as coronavirus-2 (SARS-CoV-2). Furthermore, the side effect of synthetic antiviral drugs and reduced efficacy against resistant variants have reinforced the search for alternative and effective treatment options, such as plant-derived antiviral molecules. Curcumin (CUR) and quercetin (QUE) are two natural compounds that have been widely studied for their health benefits, such as antiviral and anti-inflammatory activity. However, poor oral bioavailability limits the clinical applications of these natural compounds. In this work, nanoemulsions (NE) co-encapsulating CUR and QUE designed for nasal administration were developed as promising prophylactic and therapeutic treatments for viral respiratory infections. The NEs were prepared by high-pressure homogenization combined with the phase inversion temperature technique and evaluated for their physical and chemical characteristics. In vitro assays were performed to evaluate the nanoemulsion retention into the porcine nasal mucosa. In addition, the CUR and QUE-loaded NE antiviral activity was tested against a murine β-COV, namely MHV-3. The results evidenced that CUR and QUE loaded NE had a particle size of 400 nm and retention in the porcine nasal mucosa. The antiviral activity of the NEs showed a percentage of inhibition of around 99 %, indicating that the developed NEs has interesting properties as a therapeutic and prophylactic treatment against viral respiratory infections.

Enhanced Stability and Solidification of Volatile Eugenol by Cyclodextrin-Metal Organic Framework for Nasal Powder Delivery

Eugenol (Eug) holds potential as a treatment for bacterial rhinosinusitis by nasal powder drug delivery. To stabilization and solidification of volatile Eug, herein, nasal inhalable γ-cyclodextrin metal-organic framework (γ-CD-MOF) was investigated as a carrier by gas-solid adsorption method. The results showed that the particle size of Eug loaded by γ-CD-MOF (Eug@γ-CD-MOF) distributed in the range of 10-150 μm well. In comparison to γ-CD and β-CD-MOF, γ-CD-MOF has higher thermal stability to Eug. And the intermolecular interactions between Eug and the carriers were verified by characterizations and molecular docking. Based on the bionic human nasal cavity model, Eug@γ-CD-MOF had a high deposition distribution (90.07 ± 1.58%). Compared with free Eug, the retention time Eug@γ-CD-MOF in the nasal cavity was prolonged from 5 min to 60 min. In addition, the cell viability showed that Eug@γ-CD-MOF (Eug content range 3.125-200 µg/mL) was non-cytotoxic. And the encapsulation of γ-CD-MOF could not reduce the bacteriostatic effect of Eug. Therefore, the biocompatible γ-CD-MOF could be a potential and valuable carrier for nasal drug delivery to realize solidification and nasal therapeutic effects of volatile oils.

Essential considerations towards development of effective nasal antibiotic formulation: features, strategies, and future directions

INTRODUCTION

Intranasal antibiotic products are gaining popularity as a promising method of administering antibiotics, which provide numerous benefits, e.g. enhancing drug bioavailability, reducing adverse effects, and potentially minimizing resistance threats. However, some issues related to the antibiotic substances and nasal route challenges must be addressed to prepare effective formulations.

AREAS COVERED

This review focuses on the valuable points of nasal delivery as an alternative route for administering antibiotics, coupled with the challenges in the nasal cavity that might affect the formulations. Moreover, this review also highlights the application of nasal delivery to introduce antibiotics for local therapy, brain targeting, and systemic effects that have been conducted. In addition, this viewpoint provides strategies to maintain antibiotic stability and several crucial aspects to be considered for enabling effective nasal formulation.

EXPERT OPINION

In-depth knowledge and understanding regarding various key considerations with respect to the antibiotic substances and nasal route delivery requirement in preparing effective nasal antibiotic formulation would greatly improve the development of nasally administered antibiotic products, enabling better therapeutic outcomes of antibiotic treatment and establishing appropriate use of antibiotics, which in turn might reduce the chance of antibiotic resistance and enhance patient comfort.

Development of favipiravir dry powders for intranasal delivery: An integrated cocrystal and particle engineering approach via spray freeze drying

The therapeutic potential of pharmaceutical cocrystals in intranasal applications remains largely unexplored despite progressive advancements in cocrystal research. We present the application of spray freeze drying (SFD) in successful fabrication of a favipiravir-pyridinecarboxamide cocrystal nasal powder formulation for potential treatment of broad-spectrum antiviral infections. Preliminary screening via mechanochemistry revealed that favipiravir (FAV) can cocrystallize with isonicotinamide (INA), but not nicotinamide (NCT) and picolinamide (PIC) notwithstanding their structural similarity. The cocrystal formation was characterized by differential scanning calorimetry, Fourier-transform infrared spectroscopy, and unit cell determination through Rietveld refinement of powder X-ray analysis. FAV-INA crystalized in a monoclinic space group P21/c with a unit cell volume of 1223.54(3) Å3, accommodating one FAV molecule and one INA molecule in the asymmetric unit. The cocrystal was further reproduced as intranasal dry powders by SFD, of which the morphology, particle size, in vitro drug release, and nasal deposition were assessed. The non-porous flake shaped FAV-INA powders exhibited a mean particle size of 19.79 ± 2.61 μm, rendering its suitability for intranasal delivery. Compared with raw FAV, FAV-INA displayed a 3-fold higher cumulative fraction of drug permeated in Franz diffusion cells at 45 min (p = 0.001). Dose fraction of FAV-INA deposited in the nasal fraction of a customized 3D-printed nasal cast reached over 80 %, whereas the fine particle fraction remained below 6 % at a flow rate of 15 L/min, suggesting high nasal deposition whilst minimal lung deposition. FAV-INA was safe in RPMI 2650 nasal and SH-SY5Y neuroblastoma cells without any in vitro cytotoxicity observed. This study demonstrated that combining the merits of cocrystallization and particle engineering via SFD can propel the development of advanced dry powder formulations for intranasal drug delivery.

What Are the Key Anatomical Features for the Success of Nose-to-Brain Delivery? A Study of Powder Deposition in 3D-Printed Nasal Casts

Nose-to-brain delivery is a promising way to improve the treatment of central nervous system disorders, as it allows the bypassing of the blood-brain barrier. However, it is still largely unknown how the anatomy of the nose can influence the treatment outcome. In this work, we used 3D printing to produce nasal replicas based on 11 different CT scans presenting various anatomical features. Then, for each anatomy and using the Design of Experiments methodology, we characterised the amount of a powder deposited in the olfactory region of the replica as a function of multiple parameters (choice of the nostril, device, orientation angle, and the presence or not of a concomitant inspiration flow). We found that, for each anatomy, the maximum amount of powder that can be deposited in the olfactory region is directly proportional to the total area of this region. More precisely, the results show that, whatever the instillation strategy, if the total area of the olfactory region is below 1500 mm2, no more than 25% of an instilled powder can reach this region. On the other hand, if the total area of the olfactory region is above 3000 mm2, the deposition efficiency reaches 50% with the optimal choice of parameters, whatever the other anatomical characteristics of the nasal cavity. Finally, if the relative difference between the areas of the two sides of the internal nasal valve is larger than 20%, it becomes important to carefully choose the side of instillation. This work, by predicting the amount of powder reaching the olfactory region, provides a tool to evaluate the adequacy of nose-to-brain treatment for a given patient. While the conclusions should be confirmed via in vivo studies, it is a first step towards personalised treatment of neurological pathologies.

Preparation and Optimization of Bovine Serum Albumin Nanoparticles as a Promising Gelling System for Enhanced Nasal Drug Administration

Bovine serum albumin (BSA) has been used extensively as a suitable carrier system for alternative drug delivery routes, such as nasal administration. However, the optimization of BSA nanoparticles with respect to their nasal applicability has not been widely studied. The present study focuses on the characterization of BSA nanoparticles prepared using the desolvation method, followed by a gelation process to facilitate intranasal drug delivery. The results demonstrated that the ratio of BSA and the desolvating agent, ethanol, played a critical role in the nanoparticle characteristics of the BSA nanogel matrices (BSA-NGs). Based on the gelling properties, the formulations of BSA-NG 2, BSA-NG 4, and BSA-NG 6 were selected for further investigation. The Raman spectra confirmed that there were no specific changes to the secondary structures of the BSA. The mucoadhesion studies revealed moderately high mucoadhesive properties, with a mucin binding efficiency (MBE) value of around 67%, allowing the dose to avoid elimination due to rapid mucociliary clearance of the nasal passage. Via studying the nexus of the carrier system, BSA-NGs loaded with dexamethasone as a model drug were prepared and evaluated by differential scanning calorimetry (DSC) and thermal gravimetry (TG), ascertaining that no ethanol remained in the samples after the freeze-drying process. Furthermore, the viscosity measurements exhibited moderate viscosity, which is suitable for nasal liquid preparations. The in vitro release studies performed with a simulated nasal electrolyte solution (SNES) medium showed 88.15-95.47% drug release within 4 h. In conclusion, BSA nanoparticle gelling matrices can offer potential, value-added drug delivery carriers for improved nasal drug administration.

Non-Invasive Vaccines: Challenges in Formulation and Vaccine Adjuvants

Given the limitations of conventional invasive vaccines, such as the requirement for a cold chain system and trained personnel, needle-based injuries, and limited immunogenicity, non-invasive vaccines have gained significant attention. Although numerous approaches for formulating and administrating non-invasive vaccines have emerged, each of them faces its own challenges associated with vaccine bioavailability, toxicity, and other issues. To overcome such limitations, researchers have created novel supplementary materials and delivery systems. The goal of this review article is to provide vaccine formulation researchers with the most up-to-date information on vaccine formulation and the immunological mechanisms available, to identify the technical challenges associated with the commercialization of non-invasive vaccines, and to guide future research and development efforts.

The Potential of the Nose-to-Brain Delivery of PACAP for the Treatment of Neuronal Disease

Research on the neuroprotective effect of pituitary adenylate cyclase-activating polypeptide (PACAP) and its use as a therapeutic agent has grown over the past 30 years. Both in vitro and in vivo experiments have shown that PACAP exerts a strong neuroprotective effect in many central and peripheral neuronal diseases. Various delivery routes have been employed from intravenous (IV) injections to intracerebroventricular (ICV) administration, leading either to systemic or topical delivery of the peptide. Over the last decade, a growing interest in the use of intranasal (IN) administration of PACAP and other therapeutic agents has emerged as an alternative delivery route to target the brain. The aim of this review is to summarize the findings on the neuroprotective effect of PACAP and to discuss how the IN administration of PACAP could contribute to target the effects of this pleiotropic peptide.

Nasal delivery as a strategy for the prevention and treatment of COVID-19

INTRODUCTION

The upper respiratory tract is a major route of infection for COVID-19 and other respiratory diseases. Thus, it appears logical to exploit the nose as administration site to prevent, fight, or minimize infectious spread and treat the disease. Numerous nasal products addressing these aspects have been considered and developed for COVID-19.

AREAS COVERED

This review gives a comprehensive overview of the different approaches involving nasal delivery, i.e., nasal vaccination, barrier products, and antiviral pharmacological treatments that have led to products on the market or under clinical evaluation, highlighting the peculiarities of the nose as application and absorption site and pointing at key aspects of nasal drug delivery.

EXPERT OPINION

From the analysis of nasal delivery strategies to prevent or fight COVID-19, it emerges that, especially for nasal immunization, formulations appear the same as originally designed for parenteral administration, leading to suboptimal results. On the other hand, mechanical barrier and antiviral products, designed to halt or treat the infection at early stage, have been proven effective but were rarely brought to the clinics. If supported by robust and targeted product development strategies, intranasal immunization and drug delivery can represent valid and sometimes superior alternatives to more conventional parenteral and oral medications.

Chitosan-Based Thermogelling System for Nose-to-Brain Donepezil Delivery: Optimising Formulation Properties and Nasal Deposition Profile

Donepezil nasal delivery strategies are being continuously investigated for advancing therapy in Alzheimer's disease. The aim of this study was to develop a chitosan-based, donepezil-loaded thermogelling formulation tailored to meet all the requirements for efficient nose-to-brain delivery. A statistical design of the experiments was implemented for the optimisation of the formulation and/or administration parameters, with regard to formulation viscosity, gelling and spray properties, as well as its targeted nasal deposition within the 3D-printed nasal cavity model. The optimised formulation was further characterised in terms of stability, in vitro release, in vitro biocompatibility and permeability (using Calu-3 cells), ex vivo mucoadhesion (using porcine nasal mucosa), and in vivo irritability (using slug mucosal irritation assay). The applied research design resulted in the development of a sprayable donepezil delivery platform characterised by instant gelation at 34 °C and olfactory deposition reaching a remarkably high 71.8% of the applied dose. The optimised formulation showed prolonged drug release (t_1/2 about 90 min), mucoadhesive behaviour, and reversible permeation enhancement, with a 20-fold increase in adhesion and a 1.5-fold increase in the apparent permeability coefficient in relation to the corresponding donepezil solution. The slug mucosal irritation assay demonstrated an acceptable irritability profile, indicating its potential for safe nasal delivery. It can be concluded that the developed thermogelling formulation showed great promise as an efficient donepezil brain-targeted delivery system. Furthermore, the formulation is worth investigating in vivo for final feasibility confirmation.

In vitro Evaluation of Paliperidone Palmitate Loaded Cubosomes Effective for Nasal-to-Brain Delivery

Introduction

This work aimed to develop chitosan-coated cubosomal nanoparticles intended for nose-to-brain delivery of paliperidone palmitate. They were compared with standard and cationic cubosomal nanoparticles. This comparison relies on numerous classical in vitro tests and powder deposition within a 3D-printed nasal cast.

Methods

Cubosomal nanoparticles were prepared by a Bottom-up method followed by a spray drying process. We evaluated their particle size, polydispersity index, zeta-potential, encapsulation efficiency, drug loading, mucoaffinity properties and morphology. The RPMI 2650 cell line was used to assess the cytotoxicity and cellular permeation. An in vitro deposition test within a nasal cast completed these measurements.

Results

The selected chitosan-coated cubosomal nanoparticles loaded with paliperidone palmitate had a size of 305.7 ± 22.54 nm, their polydispersity index was 0.166 ± 0.022 and their zeta potential was +42.4 ± 0.2 mV. This formulation had a drug loading of 70% and an encapsulation efficiency of 99.7 ± 0.1%. Its affinity with mucins was characterized by a ΔZP of 20.93 ± 0.31. Its apparent permeability coefficient thought the RPMI 2650 cell line was 3.00E-05 ± 0.24E-05 cm/s. After instillation in a 3D-printed nasal cast, the fraction of the injected powder deposited in the olfactory region reached 51.47 ± 9.30% in the right nostril and 41.20 ± 4.59% in the left nostril, respectively.

Conclusion

The chitosan coated cubosomal formulation seems to be the most promising formulation for nose-to-brain delivery. Indeed, it has a high mucoaffinity and a significantly higher apparent permeability coefficient than the two other formulations. Finally, it reaches well the olfactory region.

Nanotechnological Advances for Nose to Brain Delivery of Therapeutics to Improve the Parkinson Therapy

Blood-Brain Barrier (BBB) acts as a highly impermeable barrier, presenting an impediment to the crossing of most classical drugs targeted for neurodegenerative diseases including Parkinson's disease (PD). About the nature of drugs and other potential molecules, they impose unavoidable doserestricted limitations eventually leading to the failure of therapy. However, many advancements in formulation technology and modification of delivery approaches have been successful in delivering the drug to the brain in the therapeutic window. The nose to the brain (N2B) drug delivery employing the nanoformulation, is one such emerging delivery approach, overcoming both classical drug formulation and delivery-associated limitations. This latter approach offers increased bioavailability, greater patient acceptance, lesser metabolic degradation of drugs, circumvention of BBB, ample drug loading along with the controlled release of the drugs. In N2B delivery, the intranasal (IN) route carries therapeutics firstly into the nasal cavity followed by the brain through olfactory and trigeminal nerve connections linked with nasal mucosa. The N2B delivery approach is being explored for delivering other biologicals like neuropeptides and mitochondria. Meanwhile, this N2B delivery system is associated with critical challenges consisting of mucociliary clearance, degradation by enzymes, and drug translocations by efflux mechanisms. These challenges finally culminated in the development of suitable surfacemodified nano-carriers and Focused- Ultrasound-Assisted IN as FUS-IN technique which has expanded the horizons of N2B drug delivery. Hence, nanotechnology, in collaboration with advances in the IN route of drug administration, has a diversified approach for treating PD. The present review discusses the physiology and limitation of IN delivery along with current advances in nanocarrier and technical development assisting N2B drug delivery.

Lipid and Polymeric Nanoparticles: Successful Strategies for Nose-to-Brain Drug Delivery in the Treatment of Depression and Anxiety Disorders

Intranasal administration has gained an increasing interest for brain drug delivery since it allows direct transport through neuronal pathways, which can be quite advantageous for central nervous system disorders, such as depression and anxiety. Nanoparticles have been studied as possible alternatives to conventional formulations, with the objective of improving drug bioavailability. The present work aimed to analyze the potential of intranasal nanoparticle administration for the treatment of depression and anxiety, using the analysis of several studies already performed. From the carried-out analysis, it was concluded that the use of nanoparticles allows the drug's protection from enzymatic degradation, and the modulation of its components allows controlled drug release and enhanced drug permeation. Furthermore, the results of in vivo studies further verified these systems' potential, with the drug reaching the brain faster and leading to increased bioavailability and, consequently, therapeutic effect. Hence, in general, the intranasal administration of nanoparticles leads to a faster onset of action, with increased and prolonged brain drug concentrations and, consequently, therapeutic effects, presenting high potential as an alternative to the currently available therapies for the treatment of depression and anxiety.

Tailoring functional spray-dried powder platform for efficient donepezil nose-to-brain delivery

Shortcomings of oral donepezil administration in the treatment of Alzheimer's disease have paved the way for ongoing investigations towards more efficient and safe donepezil nose-to-brain delivery. Herein we present the development of advantageous powder platform for donepezil nose-to-brain delivery, coupling careful design of chitosan and mannitol-based carrier matrix with spray-drying technology advantages and early consideration of adequate nasal administration mode, employing QbD approach. Unprecedentedly, ultrasonic nozzle was used to atomise the drying feed in response to size-related requirements for nasal aerosol particles. The optimised spray-drying process resulted in free-flowable dry powder with a great majority of particles larger than 10 µm, ensuring localised nasal deposition upon aerosolization, as evidenced by using 3D-printed nasal cavity model. QbD approach coupling formulation, process and administration parameters enabled optimisation of drug deposition profile reaching tremendously high 65.5 % of the applied dose deposited in the olfactory region. The leading formulation exhibited favourable swelling, mucoadhesion, drug release and permeation-enhancing properties, suiting the needs for efficient brain-targeted delivery. Results of in vitro biocompatibility and physico-chemical stability studies confirmed the leading formulation potential for safe and efficient donepezil nose-to-brain delivery. The obtained results encourage extending the study to an appropriate in vivo model needed for the final proof-of-concept.

Instillation of a Dry Powder in Nasal Casts: Parameters Influencing the Olfactory Deposition With Uni- and Bi-Directional Devices

Nose-to-brain delivery is a promising way to reach the central nervous system with therapeutic drugs. However, the location of the olfactory region at the top of the nasal cavity complexifies this route of administration. In this study, we used a 3D-printed replica of a nasal cavity (a so-called “nasal cast”) to reproduce in vitro the deposition of a solid powder. We considered two different delivery devices: a unidirectional device generating a classical spray and a bidirectional device that relies on the user expiration. A new artificial mucus also coated the replica. Five parameters were varied to measure their influence on the powder deposition pattern in the olfactory region of the cast: the administration device, the instillation angle and side, the presence of a septum perforation, and the flow rate of possible concomitant inspiration. We found that the unidirectional powder device is more effective in targeting the olfactory zone than the bi-directional device. Also, aiming the spray nozzle directly at the olfactory area is more effective than targeting the center of the nasal valve. Moreover, the choice of the nostril and the presence of a perforation in the septum also significantly influence the olfactory deposition. On the contrary, the inspiratory flow has only a minor effect on the powder outcome. By selecting the more efficient administration device and parameters, 44% of the powder can reach the olfactory region of the nasal cast.

Intranasal Delivery of Darunavir-Loaded Mucoadhesive In Situ Gel: Experimental Design, In Vitro Evaluation, and Pharmacokinetic Studies

The clinical efficacy of antiretroviral therapy in NeuroAIDS is primarily limited by the low perfusion of the drug to the brain. The objective of the current investigation was to design and develop an in situ mucoadhesive gel loaded with darunavir to assess the feasibility of brain targeting through the intranasal route. Preliminary batches (F1−F9) were prepared and evaluated for various pharmaceutical characteristics. A full factorial design of the experiment was applied to optimize and assess the effect of two influencing variables (Carbopol 934P (X1) and Poloxamer 407 (X2)) on the response effects (gelation temperature (Y1) and % drug release (Y2) at 8 h). The data demonstrate that both influencing variables affect the response variables significantly (p < 0.05). The optimized formulation (F7) exhibited favorable rheological properties, adequate mucoadhesion, sustained drug release, and greater permeation across the nasal mucosa. An in vitro ciliotoxicity study confirms the nontoxicity of the optimized in situ gel (D7) on the nasal mucosa. An in vivo pharmacokinetic study in rats was performed to assess drug targeting to the brain following the nasal application of the selected in situ gel (D7). Significantly higher (p < 0.0001) Cmax (~4-fold) and AUC0-α (~3.5-fold) values were noticed in the brain after nasal application, as compared to the intravenous route. However, less systemic exposure to darunavir was noticed with nasal therapy, which confirms the low absorption of the drug into the central compartment. Overall, the data here demonstrate that the optimized in situ mucoadhesive nasal gel is effective in targeting darunavir to the brain by the nasal route and could be a viable option for the treatment of NeuroAIDS.

Spray dried powders for nasal delivery: Process and formulation considerations

Powders for nasal delivery have been recognized as advantageous dosage forms over liquids due to increased stability and residence time on nasal mucosa, with improved bioavailability. They can be manufactured by spray-drying, allowing the optimization of the particle properties that are critical to guarantee nasal deposition, as size and shape. It is also a scalable and flexible method already explored extensively in the pharmaceutical industry. However, it is important to understand how process parameters, particle physical properties and formulation considerations affect the product performance. Hence, this review aims to provide an overview of nasal powder formulation and processing through spray drying, with an emphasis on the variables that impact on performance. To this purpose, we describe the physical, biological and pharmacological phenomena prior to drug absorption as well as the most relevant powder properties. Formulation considerations including qualitative and quantitative composition are then reviewed, as well as manufacturing considerations including spray drying relevant parameters.

A Novel Faster-Acting, Dry Powder-Based, Naloxone Intranasal Formulation for Opioid Overdose

OBJECTIVE

To examine the pharmacokinetics and safety of FMXIN001, a new intranasal powder-based naloxone formulation, in comparison to Narcan® nasal liquid spray.

METHODS

FMXIN001, was developed by blending drug microspheres with larger lactose monohydrate particles, that serve as diluent and carrier, as well as a disaggregating agent. Scanning electron microscopy and X-ray were used to characterize the formulation and in vitro deposition was investigated using a nasal cast. We compared the pharmacokinetics and safety of FMXIN001 versus Narcan® in two clinical trials: a pilot study with 14 healthy adults and a pivotal trial in 42 healthy adults (NCT04713709). The studies were open-label, single-dose, randomized, two-period, two-treatment, two-sequence crossover studies to assess the pharmacokinetics and safety of FMXIN001 versus Narcan® nasal spray.

RESULTS

FMXIN001 comprises naloxone microspheres (5-30 μM) and lactose particles (40-240 μM). Upon in vitro testing, naloxone deposits mainly to the middle turbinates region and the upper part of the nasal cavity of a nasal cast. In human subjects, FMXIN001 produced significantly higher exposure at the initial time points of 4, 10, and 30 min, post-administration, compared to Narcan®. Both treatments were safe and well tolerated. FMXIN001, powder-based spray, results in similar overall exposure to Narcan®, but with more rapid absorption in the first 30 min.

CONCLUSIONS

FMXIN001 is expected to have a shorter onset of action for a more effective therapeutic intervention to manage opioid overdose. Rapid administration of naloxone in cases of opioid overdose is imperative, given the alarming increase in mortality rates.

Nose-to-brain drug delivery for the treatment of Alzheimer's Disease: Current advancements and challenges

INTRODUCTION

The irreversible destruction of neurons, progressive loss of memory and cognitive behavior, high cost of therapy, and impact on society desire a better, effective, and affordable treatment of AD. The nose-to-brain drug delivery approach holds a great potential to access the brain without any hindrance of BBB and result in higher bioavailability thus better therapeutic efficacy of anti-AD drugs.

AREAS COVERED

The present review article highlighted the current facts and worldwide statistics of AD and its detailed etiology. Followed by barriers to brain delivery, nose-to-brain delivery, their limitations, and amalgamation with various novel carrier systems. We have emphasized recent advancements in nose-to-brain delivery using mucoadhesive, stimuli-responsive carriers, polymeric nanoparticles, lipid nanoparticles, protein/peptide delivery for treatment of AD.

EXPERT OPINION

The available therapies are symptomatic, mitigate the symptoms of AD at the initial stages. In this lieu, nose-to-brain delivery has the ability to overcome these limitations and increase drug bioavailability in the brain. Various novel strategies including stimuli-responsive systems, nanoparticles, etc. enhance the nasal drug permeation, protects the drug, and enhance its therapeutic potency. Although, successful preclinical data does not assure the clinical success of the therapy and hence exhaustive clinical investigations are needed to make the therapy available for patients.

Nasal vaccine as a booster shot: a viable solution to restrict pandemic?

The coronavirus disease 2019 (COVID-19) pandemic revolutionized the vaccine market and initiated the momentum for alternative routes of administration for vaccines. The intranasal route of immunization is one such possibility that appears to be the most promising since it has some significant advantages, particularly in the prevention of respiratory infection. To analyze and summarize the role of nasal vaccines over conventional vaccines during COVID-19 and the need for the nasal vaccine as a booster shot. In this narrative review, the required data was retrieved using keywords “COVID-19,” “Intranasal,” “Immunity,” “Nasal spray,” and “Mucosal” in databases including PubMed, Scopus, Embase, Science Direct, and Web of Sciences. The results of the study showed that the nasal vaccines were both effective and protective according to the current researches approaching during the COVID-19 period and the preclinical and clinical phase trials prove the intranasal vaccination elicits more robust and cross-protective immunity than conventional vaccines. In this narrative review article, mechanisms across the nasal mucosa will be briefly presented and the current status of nasal vaccines during the COVID-19 pandemic is summarized, and advantages over traditional vaccines are provided. Furthermore, after exploring the primary benefits and kinetics of nasal vaccine, the potential for consideration of nasal vaccine as a booster dose is also discussed.

Cerebral and extracerebral distribution of radioactivity associated with oxytocin in rabbits after intranasal administration: Comparison of TTA-121, a newly developed oxytocin formulation, with Syntocinon

Autism spectrum disorder (ASD) is a neurodevelopmental disorder associated with deficits in social interactions/communication. Despite the large number of ASD patients, there is no drug approved to treat its core symptoms. Recently, Syntocinon (oxytocin nasal spray) has been reported to have a therapeutic effect on ASD. However, the disadvantage of Syntocinon for ASD treatment is that 6 puffs/administration are required to achieve the effective pharmacological dose. Furthermore, there are no published reports evaluating the cerebral distribution profile of oxytocin after intranasal administration. TTA-121 is a newly developed intranasal oxytocin formulation with high bioavailability produced by optimizing the physicochemical properties. In this study, we prepared the same formula as Syntocinon as the control formulation (CF), and the cerebral and extracerebral distribution of oxytocin in rabbits after single intranasal administration of ³H-labeled oxytocin formulations—[³H]TTA-121 and [³H]CF were examined and compared. The area under the concentration-time curve to the time of the last quantifiable concentration (AUC_t) in the whole brain was 3.6-fold higher in the [³H]TTA-121 group than in the [³H]CF group, indicating increased delivery of radioactivity to the brain by TTA-121 than by CF. Since the distribution profiles showed no notable differences in radioactivity between the olfactory bulb and trigeminal nerve, intranasally-administered oxytocin was probably transferred to the brain via both pathways. The results also showed an increase in radioactivity in the prefrontal area and the precuneus, which are probable sites of pharmacological action as shown in clinical studies using functional magnetic resonance imaging (fMRI), confirming that intranasally-administered oxytocin could reach these tissues.

Nasal powders of quercetin-β-cyclodextrin derivatives complexes with mannitol/lecithin microparticles for Nose-to-Brain delivery: In vitro and ex vivo evaluation

Quercetin, a flavonoid with possible neuroprotective action has been recently suggested for the early-stage treatment of Alzheimer's disease. The low solubility and extended first pass effect render quercetin unsuitable for oral administration. Alternatively, brain targeting is more feasible with nasal delivery, by-passing, non-invasively, Blood-Brain Barrier and ensuring rapid onset of action. Aiming to increase quercetin's disposition into brain, nasal powders consisting of quercetin-cyclodextrins (methyl-β-cyclodextrin and hydroxypropyl-β-cyclodextrin) lyophilizates blended with spray-dried microparticles of mannitol/lecithin were prepared. Quercetin's solubility at 37 °C and pH 7.4 was increased 19-35 times when complexed with cyclodextrins. Blending lyophilizates in various ratios with mannitol/lecithin microparticles, results in powders with improved morphological characteristics as observed by X-ray Diffraction and Scanning Electron Microscopy analysis. In vitro characterization of these powders using Franz cells, revealed rapid dissolution and permeation 17 (methyl-β-cyclodextrin) to 48 (hydroxypropyl-β-cyclodextrin) times higher than that of pure quercetin. Ex vivo powders' transport across rabbit nasal mucosa was found more efficient in comparison with the pure Que. The overall better performance of quercetin-hydroxypropyl-β-cyclodextrin powders is confirmed by ex vivo experiments revealing amount of quercetin permeated ranging from 0.03 ± 0.01 to 0.22 ± 0.05 μg/cm² for hydroxypropyl-β-cyclodextrin and 0.022 ± 0.01 to 0.17 ± 0.04 μg/cm² for methyl-β-cyclodextrin powders, while the permeation of pure quercetin was negligible.

Comparison of Modern In Vitro Permeability Methods with the Aim of Investigation Nasal Dosage Forms

Nowadays, the intranasal route has become a reliable alternative route for drug administration to the systemic circulation or central nervous system. However, there are no official in vitro diffusion and dissolution tests especially for the investigation of nasal formulations. Our main goal was to study and compare a well-known and a lesser-known in vitro permeability investigation method, in order to ascertain which was suitable for the determination of drug permeability through the nasal mucosa from different formulations. The vertical diffusion cell (Franz cell) was compared with the horizontal diffusion model (Side-Bi-Side). Raw and nanonized meloxicam containing nasal dosage forms (spray, gel and powder) were tested and compared. It was found that the Side-Bi-Side cell was suitable for the investigation of spray and powder forms. In contrast, the gel was not measurable on the Side-Bi-Side cell; due to its high viscosity, a uniform distribution of the active substance could not be ensured in the donor phase. The Franz cell, designed for the analysis of semi-solid formulations, was desirable for the investigation of nasal gels. It can be concluded that the application of a horizontal cell is recommended for liquid and solid nasal preparations, while the vertical one should be used for semi-solid formulations.

Intranasal drug delivery: opportunities and toxicologic challenges during drug development

Over the past 10 years, the interest in intranasal drug delivery in pharmaceutical R&D has increased. This review article summarises information on intranasal administration for local and systemic delivery, as well as for CNS indications. Nasal delivery offers many advantages over standard systemic delivery systems, such as its non-invasive character, a fast onset of action and in many cases reduced side effects due to a more targeted delivery. There are still formulation limitations and toxicological aspects to be optimised. Intranasal drug delivery in the field of drug development is an interesting delivery route for the treatment of neurological disorders. Systemic approaches often fail to efficiently supply the CNS with drugs. This review paper describes the anatomical, histological and physiological basis and summarises currently approved drugs for administration via intranasal delivery. Further, the review focuses on toxicological considerations of intranasally applied compounds and discusses formulation aspects that need to be considered for drug development.

Quality by Design Based Formulation Study of Meloxicam-Loaded Polymeric Micelles for Intranasal Administration

Our study aimed to develop an “ex tempore” reconstitutable, viscosity enhancer- and preservative-free meloxicam (MEL)-loaded polymeric micelle formulation, via Quality by Design (QbD) approach, exploiting the nose-to-brain pathway, as a suitable tool in the treatment of neuroinflammation. The anti-neuroinflammatory effect of nose-to-brain NSAID polymeric micelles was not studied previously, therefore its investigation is promising. Critical product parameters, encapsulation efficiency (89.4%), Z-average (101.22 ± 2.8 nm) and polydispersity index (0.149 ± 0.7) and zeta potential (−25.2 ± 0.4 mV) met the requirements of the intranasal drug delivery system (nanoDDS) and the targeted profile liquid formulation was transformed into a solid preservative-free product by freeze-drying. The viscosity (32.5 ± 0.28 mPas) and hypotonic osmolality (240 mOsmol/L) of the reconstituted formulation provides proper and enhanced absorption and probably guarantees the administration of the liquid dosage form (nasal drop and spray). The developed formulation resulted in more than 20 times faster MEL dissolution rate and five-fold higher nasal permeability compared to starting MEL. The prediction of IVIVC confirmed the great potential for in vivo brain distribution of MEL. The nose-to-brain delivery of NSAIDs such as MEL by means of nanoDDS as polymeric micelles offers an innovative opportunity to treat neuroinflammation more effectively.