Nasal mucociliary clearance as a factor in nasal drug delivery

The review of nasal drug delivery system: The strategies to enhance the efficiency of intranasal drug delivery by improving drug absorption

Nasal drug administration constitutes an efficient and non-invasive modality of drug delivery, and its distinctive physiological structure offers potentialities for treating a variety of diseases. To elevate the drug absorption and delivery efficiency, it is of paramount importance to delineate the transport routes and their enhancement mechanisms. Nevertheless, drug absorption pathways vary depending on the disease target, these variations present opportunities for targeted delivery and challenges for achieving precision. Hence, this review outlines the anatomical structure of the nasal cavity, and subsequently elaborates on the drug transport pathways within the nasal cavity and their influencing factors. Based on the distinct sites of drug action, diseases suitable for nasal drug administration are categorized into three types: systemic diseases, local nasal diseases, and central nervous system diseases. Grounded on multiple transport routes and their influencing factors, this review proposes strategies like optimizing formulation viscosity, using penetration enhancers, adding mucosal adhesives and improving delivery device, offering insights into future advancements in nasal drug delivery systems.

Emerging trends in designing polysaccharide based mucoadhesive network hydrogels as versatile platforms for innovative delivery of therapeutic agents: A review

INTRODUCTION

The rapid progress in polymer science has designed innovative materials for biomedical applications. In the case of drug design, for each new therapeutic agent, a drug delivery system (DDS) is required to improve its pharmacokinetic and pharmacodynamic parameters. Therefore, significant research has been carried out to develop drug delivery (DD) carriers for these new therapeutic agents. Hydrogels have been explored as potential candidates to prepare controlled drug delivery (CDD) systems to address the challenges related to the performance of the conventional DD formulations. Mucoadhesive drug delivery system (MUCO-DDS) is a specialized form of CDD system, facilitating site-specific DD, protecting the drug from first pass metabolism and enhancing its overall bioavailability.

METHODS

The present article provides a comprehensive discussion of the synthesis, properties and applications of polysaccharide-derived MUCO-DDS. Different natural polymer-derived MUCO-DDS including chitosan, alginate, pectin, xanthan gum, psyllium, gelatin, cellulose, hyaluronic acid, guar gum, sterculia gum and tragacanth gum have been reported. Herein, these DDS were elaborately discussed along with their applications and future-prospective. These DDS are classified on the basis of drug administration (nasal, ocular, vagina/rectal & buccal DDS) and drug distribution (reservoir and monolithic polymer matrix). Factors contributing to modifications of properties of MUCO-DDS were also demonstrated along with different stages and theories of mucoadhesion.

RESULTS

Polysaccharides exhibit properties such as biocompatibility, biodegradability, and flexibility, making them ideal for CDD applications. MUCO-DDS demonstrates several significant advantages. Moreover, the article bridges theoretical insights with practical applications and future research prospects, ensuring its relevance for advancements in the concerned field. This review serves as a comprehensive resource, addressing gaps in previous literature and paving the way for innovations in MUCO-DDS, through a comparative analysis of the advantages, limitations, and modifications of natural polymers.

CONCLUSIONS

In conclusion, this review gives an overview of the current developments in the field of mucoadhesive DD systems and also gives insights into the future perspectives. The MUCOAD of DDS could be modulated by the inclusion of various natural and synthetic components in hydrogels. Future directions for the researchers are underway to integrate nanotechnology with mucoadhesive systems to create hybrid platforms. Overall, by addressing current limitations and leveraging emerging technologies, these systems can revolutionize drug delivery for a wide range of therapeutic applications.

Super-resolving particle diffusion heterogeneity in porous hydrogels via high-speed 3D active-feedback single-particle tracking microscopy

Nanoparticle diffusion in 3D porous structures is critical to understanding natural and synthetic systems but remains underexplored due to limitations in traditional microscopy methods. Here, we use 3D Single-Molecule Active-feedback Real-time Tracking (3D-SMART) microscopy to resolve nanoparticle dynamics in agarose gels with unprecedented spatiotemporal resolution. We highlight 'hopping diffusion', where particles intermittently escape confinement pockets, providing insights into hydrogel microstructure. Long, highly sampled trajectories enable extraction of kinetic parameters, confinement sizes, and thermodynamic barriers. This study demonstrates 3D-SMART's ability to probe particle-environment interactions at super-resolution (~10 nm in XY and ~30 nm in Z) in 3D, offering new perspectives on nanoparticle diffusion and the structural dynamics of porous materials, with implications for drug delivery, material science, and biological systems.

Advancements in Nanoemulsion-Based Drug Delivery Across Different Administration Routes

Nanoemulsions (NEs) have emerged as effective drug delivery systems over the past few decades due to their multifaceted nature, offering advantages such as enhanced bioavailability, protection of encapsulated compounds, and low toxicity. In the present review, we focus on advancements in drug delivery over the last five years across (trans)dermal, oral, ocular, nasal, and intra-articular administration routes using NEs. Rational selection of components, surface functionalization, incorporation of permeation enhancers, and functionalization with targeting moieties are explored for each route discussed. Additionally, apart from NEs, we explore NE-based drug delivery systems (e.g., NE-based gels) while highlighting emerging approaches such as vaccination and theranostic applications. The growing interest in NEs for drug delivery purposes is reflected in clinical trials, which are also discussed. By summarizing the latest advances, exploring new strategies, and identifying critical challenges, this review focuses on developments for efficient NE-based therapeutic approaches.

Enhancing Galantamine Distribution in Rat Brain Using Microplasma-Assisted Nose-to-Brain Drug Delivery

Nose-to-brain (N2B) drug delivery is a promising technique for the treatment of brain diseases. It allows a drug to enter the brain without passing through the blood-brain barrier. However, the nasal cavity and nasal mucosa can restrict the amount of drug absorbed. Recent studies of non-thermal plasma (NTP) have shown improvement in in vitro drug delivery to cells and tissues. However, whether NTP treatments can enhance the in vivo delivery of drugs for neurodegenerative disease like Alzheimer's disease (AD) into the brain via the N2B technique remains unclear. The drug used in this study was galantamine hydrobromide. Galantamine is used to treat patients with mild to moderate AD. Based on the principle of NTP, a type of dielectric barrier discharge (DBD) plasma, which we called spiral DBD microplasma, was designed. It was inserted into the nose of a rat to a depth of 2 mm. The spiral DBD microplasma was driven by a sinusoidal voltage for 4 min, followed by the immediate administration of galantamine. The effect of the microplasma treatment on the distribution of galantamine in the brain was evaluated using matrix-assisted laser desorption/ionization-imaging mass spectrometry (MALDI-IMS). The results showed a high distribution of galantamine in the left and right brain hemispheres of the rat treated with plasma discharge compared to a control treated without plasma discharge. The spiral DBD microplasma is a novel contribution to DBD plasma designs. In addition, this technique for drug delivery has also created a novel approach with potential for becoming a non-invasive method of enhancing drug distribution in the brain for the treatment of neurological disorders.

Recent Advances in Studying In Vitro Drug Permeation Across Mucosal Membranes

Transmucosal drug products, such as aerosols, films, semisolids, suppositories, and tablets, have been developed for the treatment of various human diseases and conditions. Transmucosal drug absorption is highly influenced by the biological structures of the mucosa and the physiological environment specific to the administration route (e.g., nasal, rectal, and vaginal). Over the last few decades, in vitro permeation testing (IVPT) using animal tissues or in vitro cell cultures have been utilized as a cost-effective and efficient tool for evaluating drug release and permeation behavior, assisting in formulation development and quality control of transmucosal drug delivery systems. This review summarizes the key mucosal permeation barriers associated with representative transmucosal administration routes, as well as considerations for IVPT method development. It highlights various IVPT methods, including vertical diffusion cell, flow-through diffusion cell, Ussing chamber, and transwell systems. Additionally, future perspectives are discussed, such as the use of optical methods to study in vitro drug permeation and the development of in vitro-in vivo correlation (IVIVC) for transmucosal drug development. The potential of IVPT as part of in vitro bioequivalence assessment strategies for locally acting transmucosal drug products is also highlighted.

Investigation of a Thermoresponsive In Situ Hydrogel Loaded with Nanotriphala: Implications for Antioxidant, Anti-Inflammatory, and Antimicrobial Therapy in Nasal Disorders

Oxidative stress plays a crucial role in chronic nasal disorders, contributing to inflammation, tissue damage, and impaired mucosal function, highlighting the need for targeted therapies. Recent advancements in nasal drug delivery systems have expanded their applications for treating respiratory and inflammatory conditions. Among these, hydrogel-based systems offer prolonged release of active pharmaceutical ingredients (APIs), enhancing therapeutic efficacy and reducing dosing frequency. This study initially evaluates the antioxidant, anti-inflammatory, antimicrobial, and cytotoxic properties of Nanotriphala, followed by its incorporation into a thermoresponsive in situ hydrogel system, which was subsequently developed and characterized as a novel formulation. Nanotriphala exhibited >90% cell viability and significantly reduced nitric oxide (NO) levels by 40.55 µg/mL at 250 µg/mL. The hydrogel was characterized by key parameters, including viscosity, gelling time, pH, gelling temperature, texture analysis, and ex vivo spreadability. Stability was assessed under various conditions, and mutagenicity and antimutagenicity were evaluated using the Ames test. Results showed that the hydrogel gelled at 34 °C, exhibited good spreadability (10.25 ± 0.28 cm), a viscosity of 227 ± 22 cP, and maintained a pH of 5.75 ± 0.01, with optimal hardness and adhesiveness suitable for nasal application. It demonstrated antimicrobial activity against E. coli, P. aeruginosa, S. aureus, and S. epidermidis at minimal bactericidal concentrations (MBCs) of 32, 2, 4, and 8 µg/mL, respectively, with low mutagenicity (mutagenic index < 2) and strong antimutagenic activity (>60%). The gallic acid content was 0.5796 ± 0.0218 µg/100 mL. Stability studies confirmed optimal storage at 4 °C. These findings suggest that in situ hydrogel loaded with Nanotriphala is a promising nasal drug delivery system for managing oxidative stress and related inflammatory conditions.

A Review on Lipid-based Nanoformulations for Targeting Brain through Non-invasive Nasal Route

The nasal method for administering nanoformulations to the brain has been examined and proven successful by prior investigators. For the treatment of central nervous system (CNS) disorders such as neuropsychiatric, depression, Alzheimer and anxiety, intranasal administration has become more popular for delivering drugs to the brain. This method offers direct transport through neuronal pathways. The lipid-based nanocarriers like nanostructured lipid carriers (NLC) appear more favorable than other nanosystems for brain administration. The nanostructured lipid carriers (NLC) system can quickly transform into a gelling system to facilitate easy administration into the nasal passages. The various compatibility studies showed that the other lipid structured-based formulations may not work well for various reasons, including a low drug filing capacity; during storage, the formulation showed changes in the solid lipid structures, which gives a chance of medication ejection. Formulations containing NLC can minimize these problems by improving drug solubility and permeation rate by incorporating a ratio of liquid lipids with solid lipids, resulting in improved stability during storage and drug bioavailability because of the higher drug loading capacity. This review aimed to find and emphasize research on lipid-based nanocarrier formulations that have advanced the treatment of central nervous system illnesses using nasal passages to reach the targeted area's drug molecules.

Laminar Fluid Ejection for Olfactory Drug Delivery: A Proof of Concept Study

Focal intranasal drug delivery to the olfactory cleft is a promising avenue for pharmaceuticals targeting the brain. However, traditional nasal sprays often fail to deliver enough medication to this specific area. We present a laminar fluid ejection (LFE) method for precise delivery of medications to the olfactory cleft. Using a 3D-printed model of the nasal passages, we determined the precise velocity and angle of insertion needed to deposit fluid at the olfactory cleft. Then, we conducted three proof-of-concept in-vivo imaging studies to confirm olfactory delivery in humans. First, we used Technetium-99 (a radiolabeled tracer) and methylene blue (a laboratory-made dye) to visualize olfactory deposition. Both tracers showed successful deposition. In a separate study, we used functional MRI (fMRI), to compare our LFE method with a conventional nasal spray while delivering insulin. From the fMRI results, we qualitatively observed focal decreases in brain activity in prefrontal cortex following insulin delivery. Overall, these preliminary results suggest that LFE offers a targeted approach to olfactory drug delivery, opening opportunities for access to the brain.Clinical and Translational Impact Statement - Focal deposition at the olfactory cleft is a promising target for delivering medication to the brain. We present in-human tests of a laminar fluid ejection method for intranasal drug delivery and demonstrate improvements over conventional nasal spray.

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.

Formulation and investigation of differently charged β-cyclodextrin-based meloxicam potassium containing nasal powders

Nasal systemic drug delivery may provide an easy way to substitute parenteral or oral dosing, however, the excipients have an important role in nasal formulations to increase the permeability of the mucosa and prolong the residence time of the drug. In this work, we aimed to produce meloxicam potassium monohydrate (MXP) containing nasal powders by a nano spray drier with the use of a neutral, an anionic and a cationic β-cyclodextrin as permeation enhancers, and (polyvinyl)alcohol (PVA) as a water soluble polymer. The following examinations were performed in order to study the effect of the applied excipients on the nasal applicability of the formulations: laser scattering, scanning electron microscope measurement, XRPD, DSC and FTIR measurements, adhesivity, in vitro drug release and permeability tests through an artificial membrane and RPMI 2650 cells. Based on our results, spherical particles were prepared with a size of 1.89-2.21 µm in which MXP was present in an amorphous state. Secondary interactions were formed between the excipients and the drug. The charged cyclodextrin-based formulations showed significantly higher adhesive force values regardless of the presence of PVA. The drug release was fast and complete. The passive diffusion of MXP was influenced not only by the charge of the cyclodextrin, but the presence of PVA, too. The permeation of the drug was enhanced in the presence of the anionic cyclodextrin testing it on RPMI 2650 cell model.

Oral viscous budesonide solution for enhanced localized treatment of eosinophilic esophagitis through improved mucoadhesion and permeation

Eosinophilic esophagitis (EoE) is a chronic inflammatory disease of the esophagus that is immune/antigen-mediated and often requires targeted treatment. In clinical practice, an oral viscous budesonide suspension prepared by adding sucralose to a budesonide suspension for inhalation (Pulmicort®) is used to treat adult EoE and enhance retention in the esophageal mucosa. Inspired by this off-label drug use, oral viscous budesonide solutions (OVBSs) were developed in this study, and their capacities for adhesion, permeation, and stability were explored. Given the insolubility of budesonide as a BCS II drug, we first evaluated its equilibrium solubility and found that Transcutol® HP was an excellent choice for creating an OVBS at a concentration of 0.2 mg/g. The rheological properties of the OVBSs were evaluated with a rheometer, and shear-thinning, which aids in swallowing, was observed. The addition of hydroxyethyl cellulose (HEC) increased the adhesion strength of the preparation, which was associated with the hydration and thickening mechanism. This result was confirmed in a dynamic gelation study and in vitro elution experiment conducted with porcine esophagus tissue. Furthermore, the permeabilities of the OVBSs in the porcine esophagus were evaluated with a Franz diffusion cell device. >80 % of the budesonide was released after 24 h, and the release profile was similar to that of the solution. To explore the storage conditions of OVBSs, critical factors such as pH, content, and impurities were determined. It was found that OVBSs exhibited different behaviors at different pH values and temperatures. Notably, the OVBSs containing 1.7 % HEC could be stored for >6 months at a temperature of 5 °C ± 3 °C and a pH of 4.5 without significant degradation. Overall, this study demonstrated that OVBSs have the potential to adhere to the esophageal mucosa, permeate the tissue, and remain stable during storage. Moreover, OVBSs exhibit a distinct advantage over traditional converted inhalation-to-oral budesonide therapies by enabling flexible dose adjustment in clinical applications, thereby potentially minimizing systemic side effects commonly associated with oral glucocorticoid administration.

Intranasal therapies for neonatal hypoxic-ischemic encephalopathy: Systematic review, synthesis, and implications for global accessibility to care

Neonatal hypoxic-ischemic encephalopathy (HIE) is the leading cause of neurodevelopmental morbidity in term infants worldwide. Incidence of HIE is highest in low and middle-income communities with minimal access to neonatal intensive care and an underdeveloped infrastructure for advanced neurologic interventions. Moreover, therapeutic hypothermia, standard of care for HIE in high resourced settings, is shown to be ineffective in low and middle-income communities. With their low cost, ease of administration, and capacity to potently target the central nervous system, intranasal therapies pose a unique opportunity to be a more globally accessible treatment for neonatal HIE. Intranasal experimental therapeutics have been studied in both rodent and piglet models, but no intranasal therapeutics for neonatal HIE have undergone human clinical trials. Additional research must be done to expand the array of treatments available for use as intranasal therapies for neonatal HIE thus improving the neurologic outcomes of infants worldwide.

Polyphenol-Enabled 2D Nanopatch for Enhanced Nasal Mucoadhesion and Immune Activation

The advancement of effective nasal mucoadhesive delivery faces challenges due to rapid mucociliary clearance (MCC). Conventional studies have employed mucoadhesive materials, mainly forming spherical nanoparticles, but these offer limited adhesion to the nasal mucosa. This study hypothesizes that a 2D nanoscale structure utilizing adhesive polyphenols can provide a superior strategy for countering MCC, aligning with the planar mucosal layers. We explore the use of tannic acid (TA), a polyphenolic molecule known for its adhesive properties and ability to form complexes with biomolecules. Our study introduces an unprecedented 2D nanopatch, assembled through the interaction of TA with green fluorescent protein (GFP), and cell-penetrating peptide (CPP). This 2D nanopatch demonstrates robust adhesion to nasal mucosa and significantly enhances immunoglobulin A secretions, suggesting its potential for enhancing nasal vaccine delivery. The promise of a polyphenol-enabled adhesive 2D nanopatch signifies a pivotal shift from conventional spherical nanoparticles, opening new pathways for delivery strategies through respiratory mucoadhesion.

Comparative Study of TPGS and Soluplus Polymeric Micelles Embedded in Poloxamer 407 In Situ Gels for Intranasal Administration

This study aims to highlight the importance of choosing the appropriate co-polymer or co-polymer mixed combinations in order to design value-added nasal dosage forms. Local therapy of upper respiratory tract-related infections, such as nasal rhinosinusitis is of paramount importance, thus advanced local therapeutic options are required. Dexamethasone was encapsulated into three different polymeric micelle formulations: Soluplus or TPGS-only and their mixed combinations. Dynamic light scattering measurements proved that the particles have a micelle size less than 100 nm in monodisperse distribution, with high encapsulation efficiency above 80% and an at least 7-fold water solubility increase. Tobramycin, as an antimicrobial agent, was co-formulated into the in situ gelling systems which were optimized based on gelation time and gelation temperature. The sol-gel transition takes place between 32-35 °C, which is optimally below the temperature of the nasal cavity in a quick manner below 5 min, a suitable strategic criterion against the mucociliary clearance. In vitro drug release and permeability studies confirmed a rapid kinetics in the case of the encapsulated dexamethasone accompanied with a sustained release of tobramycin, as the hydrophilic drug.

Endoscopic findings of dental implant found in the infundibulum showing the mucociliary clearance of the maxillary sinus

Significance statement: A 53-year-old man with left facial pain was referred to our hospital. Nasal endoscopy revealed a purulent discharge at the left middle meatus and bulging of the uncinate process. Computed tomography demonstrated that the dental implant was blocking the left maxillary ostium. Functional endoscopic sinus surgery was performed under general anesthesia. After removal of the uncinate process, a yellowish purulent discharge in the left maxillary sinus discharged from the maxillary sinus. The presence of the dental implant in the infundibulum shows the direction of mucociliary clearance from the nasal sinus. This case indicates how our sinus clears a foreign body, and the direction in which the foreign body is removed.

Characterization of critical parameters using an air-liquid interface model with RPMI 2650 cells for permeability studies of small molecules

The field of nasal drug delivery gained enormously on interest over the past decade. Performing nasal in vivo studies is expensive and time-consuming, but also unfeasible for an initial high-throughput compound and formulation screening. Therefore, the development of fast and high-throughput in vitro models to screen compounds for their permeability through the nasal epithelium and mucosa is constantly expanding. Yet, the protocols used for nasal in vitro permeability studies are varying, which limits the comparability and reproducibility of generated data. This project aimed to elucidate the influence of different culture and assay parameters of RPMI 2650 cells grown under air-liquid interface (ALI) conditions on the transepithelial electrical resistance (TEER) and apparent permeability (Papp) values of five selected reference compounds, covering the range of low to moderate to high permeability. The influence of the passage number, seeding density, and timepoint of airlift was minimal in our approach, while the substrate pore density had a significant influence on the Papp values of carbamazepine, propranolol, and metoprolol, classified as highly permeable compounds, but not on atenolol and aciclovir. Elevation of the experimental concentration of carbamazepine, propranolol, and metoprolol in the donor compartment had an increasing effect on the Papp values, while prolonging the assay time did not have a significant influence. Based on the results reported here, RPMI 2650 cells cultured under ALI conditions offer the possibility of a standardized high-throughput screening model for small molecules and their formulations for in vitro drug permeation studies to predict and select optimal conditions for their nasal delivery.

Nanomedicines for intranasal delivery: understanding the nano-bio interactions at the nasal mucus-mucosal barrier

INTRODUCTION

Intranasal administration is an effective drug delivery routes in modern pharmaceutics. However, unlike other in vivo biological barriers, the nasal mucosal barrier is characterized by high turnover and selective permeability, hindering the diffusion of both particulate drug delivery systems and drug molecules. The in vivo fate of administrated nanomedicines is often significantly affected by nano-biointeractions.

AREAS COVERED

The biological barriers that nanomedicines encounter when administered intranasally are introduced, with a discussion on the factors influencing the interaction between nanomedicines and the mucus layer/mucosal barriers. General design strategies for nanomedicines administered via the nasal route are further proposed. Furthermore, the most common methods to investigate the characteristics and the interactions of nanomedicines when in presence of the mucus layer/mucosal barrier are briefly summarized.

EXPERT OPINION

Detailed investigation of nanomedicine-mucus/mucosal interactions and exploration of their mechanisms provide solutions for designing better intranasal nanomedicines. Designing and applying nanomedicines with mucus interaction properties or non-mucosal interactions should be customized according to the therapeutic need, considering the target of the drug, i.e. brain, lung or nose. Then how to improve the precise targeting efficiency of nanomedicines becomes a difficult task for further research.

Nanotechnology for enhanced nose-to-brain drug delivery in treating neurological diseases

Despite the increasing global incidence of brain disorders, achieving sufficient delivery towards the central nervous system (CNS) remains a formidable challenge in terms of translating into improved clinical outcomes. The brain is highly safeguarded by physiological barriers, primarily the blood-brain barrier (BBB), which routinely excludes most therapeutics from entering the brain following systemic administration. Among various strategies investigated to circumvent this challenge, intranasal administration, a noninvasive method that bypasses the BBB to allow direct access of drugs to the CNS, has been showing promising results. Nanotechnology-based drug delivery systems, in particular, have demonstrated remarkable capacities in overcoming the challenges posed by nose-to-brain drug delivery and facilitating targeted drug accumulation within the brain while minimizing side effects of systemic distribution. This review comprehensively summarizes the barriers of nose-to-brain drug delivery, aiming to enhance our understanding of potential physiological obstacles and improve the efficacy of nasal delivery in future trials. We then highlight cutting-edge nanotechnology-based studies that enhance nose-to-brain drug delivery in three key aspects, demonstrating substantial potential for improved treatment of brain diseases. Furthermore, the attention towards clinical studies will ease the regulatory approval process for nasal administration of nanomedicines targeting brain disease.

Nebulised delivery of RNA formulations to the lungs: From aerosol to cytosol

In the past decade RNA-based therapies such as small interfering RNA (siRNA) and messenger RNA (mRNA) have emerged as new and ground-breaking therapeutic agents for the treatment and prevention of many conditions from viral infection to cancer. Most clinically approved RNA therapies are parenterally administered which impacts patient compliance and adds to healthcare costs. Pulmonary administration via inhalation is a non-invasive means to deliver RNA and offers an attractive alternative to injection. Nebulisation is a particularly appealing method due to the capacity to deliver large RNA doses during tidal breathing. In this review, we discuss the unique physiological barriers presented by the lung to efficient nebulised RNA delivery and approaches adopted to circumvent this problem. Additionally, the different types of nebulisers are evaluated from the perspective of their suitability for RNA delivery. Furthermore, we discuss recent preclinical studies involving nebulisation of RNA and analysis in in vitro and in vivo settings. Several studies have also demonstrated the importance of an effective delivery vector in RNA nebulisation therefore we assess the variety of lipid, polymeric and hybrid-based delivery systems utilised to date. We also consider the outlook for nebulised RNA medicinal products and the hurdles which must be overcome for successful clinical translation. In summary, nebulised RNA delivery has demonstrated promising potential for the treatment of several lung-related conditions such as asthma, COPD and cystic fibrosis, to which the mode of delivery is of crucial importance for clinical success.

Formulation development and evaluation of nasal in situ gel of promethazine hydrochloride

OBJECTIVE

The present work aims to develop mucoadhesive thermosensitive nasal in situ gel for Promethazine hydrochloride using quality by design (QbD) approach. It can reduce nasal mucociliary clearance (MCC) and increase residence of the drug on nasal mucosa. This might increase drug absorption to improve bioavailability of the drug as compared to oral dosage form.

SIGNIFICANCE

Promethazine hydrochloride is an antiemetic drug administered by oral, parenteral and rectal routes. These routes have poor patient compliance or low bioavailability. Nasal route is a better alternative as it has large surface area, high drug absorption rate and no first pass effect. Its only limitation is short drug retention time due to MCC. By formulating a mucoadhesive in situ gel, the MCC can be reduced, and drug absorption will be prolonged. Thus, improving bioavailability.

METHOD

In-situ gel was prepared by cold method having material attributes as concentration of Poloxamer 407 (X1) as gelling agent and hydroxypropyl methyl cellulose K4M (X2) as mucoadhesive agent. Critical Quality Attributes (CQA) were gelation temperature, mucoadhesive force and ex-vivo diffusion. Central composite design (CCD) was adopted for optimization.

RESULT

Optimized formulation satisfied all the CQA significant for nasal administration. Moreover, the formulation was found to be stable in accelerated stability studies for 3 months.

CONCLUSION

It can be concluded that since the drug can easily permeate through nasal mucosa and can gain access directly in the brain without undergoing first pass metabolism along with increased residence due to mucoadhesion, mucoadhesive in situ gel has potential to increase drug bioavailability.

The prescription design and key properties of nasal gel for CNS drug delivery: A review

Central nervous system (CNS) diseases are among the major health problems. However, blood-brain barrier (BBB) makes traditional oral and intravenous delivery of CNS drugs inefficient. The unique direct connection between the nose and the brain makes nasal administration a great potential advantage in CNS drugs delivery. However, nasal mucociliary clearance (NMCC) limits the development of drug delivery systems. Appropriate nasal gel viscosity alleviates NMCC to a certain extent, gels based on gellan gum, chitosan, carbomer, cellulose and poloxamer have been widely reported. However, nasal gel formulation design and key properties for alleviating NMCC have not been clearly discussed. This article summarizes gel formulations of different polymers in existing nasal gel systems, and attempts to provide a basis for researchers to conduct in-depth research on the key characteristics of gel matrix against NMCC.

Inhaled Medicines for Targeting Non-Small Cell Lung Cancer

Throughout the years, considerable progress has been made in methods for delivering drugs directly to the lungs, which offers enhanced precision in targeting specific lung regions. Currently, for treatment of lung cancer, the prevalent routes for drug administration are oral and parenteral. These methods, while effective, often come with side effects including hair loss, nausea, vomiting, susceptibility to infections, and bleeding. Direct drug delivery to the lungs presents a range of advantages. Notably, it can significantly reduce or even eliminate these side effects and provide more accurate targeting of malignancies. This approach is especially beneficial for treating conditions like lung cancer and various respiratory diseases. However, the journey towards perfecting inhaled drug delivery systems has not been without its challenges, primarily due to the complex structure and functions of the respiratory tract. This comprehensive review will investigate delivery strategies that target lung cancer, specifically focusing on non-small-cell lung cancer (NSCLC)-a predominant variant of lung cancer. Within the scope of this review, active and passive targeting techniques are covered which highlight the roles of advanced tools like nanoparticles and lipid carriers. Furthermore, this review will shed light on the potential synergies of combining inhalation therapy with other treatment approaches, such as chemotherapy and immunotherapy. The goal is to determine how these combinations might amplify therapeutic results, optimizing patient outcomes and overall well-being.

Challenges and opportunities in the development of mucosal mRNA vaccines

mRNA vaccines have played a critical role in controlling the SARS-CoV-2 pandemic, and are being actively studied for use in other diseases. There is a growing interest in applying mRNA vaccines at mucosal surfaces as it enables access to a unique immune reservoir in a less-invasive manner. However, mucosal surfaces present several barriers to mRNA uptake, including degrading enzymes, mucus, and clearance mechanisms. In this mini-review, we discuss our understanding of the immune response to mucosal mRNA vaccines as it compares to systemic mRNA vaccines. We also highlight physical and chemical methods for enhancing mRNA uptake across mucosal tissues. Mucosal mRNA vaccination is a nascent field of research, which will greatly benefit from fundamental investigations into the mechanisms of immune activation and the development of technologies for improved delivery.

The Pharmacokinetics of Drugs Delivered to the Upper Nasal Space

Pharmacokinetics (PK) includes how a drug is absorbed, distributed, metabolized and eliminated. The compartment providing this information is usually the plasma. This is as close to the tissue of interest that we can get, although biopsies may be obtained to give "tissue levels" of drugs. Ultimately, the goal of PK is to understand how long the drug is actually engaged with the target in the tissue of interest after a dose has been administered. Most drugs at some point in their development will have been administered intravenously (IV), which acts as the standard for 100% bioavailability. By comparing various routes of administration to IV, the percentage of drug delivered to the plasma, on a dose-normalized basis, can be calculated and is referred to as the "absolute bioavailability". As pharmacology has advanced and more drugs have become available, many older products have been reformulated to be given by routes other than those originally intended (often oral). As the drawbacks of oral (or IV) administration have become better appreciated, non-oral, non-IV formulations and methods of administration have become more popular. Nasal administration is one route that has historically been overlooked as an alternative to oral administration-particularly for products needing rapid and non-invasive access to the target tissue-mostly via the blood stream. But attention is now focused on nasal administration for direct access to the brain, as that has the potential to bypass the blood-brain-barrier (BBB), which not even IV administration can always achieve. Assessing PK for these drugs targeting the brain may require serial sampling of the cerebrospinal fluid (CSF), making PK assessments of CNS drugs more invasive and complex, but still possible in future product development. However, we are now seeing more drugs reformulated for nasal delivery to gain faster systemic levels than oral administration (especially in patients with known or suspected gastrointestinal dysmotility), while avoiding the use of needles. For example, in recent years several different formulations and delivery methods for an old drug, dihydroergotamine (DHE), have been developed and these show very different characteristics, suggesting that delivery to different parts of the nose may have very different PK profiles. This review summarizes the systemic PK of different nasal DHE options that have been, or are being, developed and suggests that delivery of drugs to the upper nasal space (UNS) may represent an optimal target. Further research is required to ascertain if this route could also be utilized for direct administration to the CNS (as an attractive alternative to intrathecal delivery) via the olfactory or trigeminal nerves-but already preclinical data (and some human data) suggest this is entirely possible.

Nanovesicular-Mediated Intranasal Drug Therapy for Neurodegenerative Disease

Numerous neurodegenerative conditions, such as Alzheimer's, Huntington's, Parkinson's, amyotrophic lateral sclerosis, and glioblastoma multiform are now becoming significant concerns of global health. Formulation-related issues, physiological and anatomical barriers, post-administration obstacles, physical challenges, regulatory limitations, environmental hurdles, and health and safety issues have all hindered successful delivery and effective outcomes despite a variety of treatment options. In the current review, we covered the intranasal route, an alternative strategic route targeting brain for improved delivery across the BBB. The trans-nasal pathway is non-invasive, directing therapeutics directly towards brain, circumventing the barrier and reducing peripheral exposure. The delivery of nanosized vesicles loaded with drugs was also covered in the review. Nanovesicle systems are organised in concentric bilayered lipid membranes separated with aqueous layers. These carriers surmount the disadvantages posed by intranasal delivery of rapid mucociliary clearance and enzymatic degradation, and enhance retention of drug to reach the site of target. In conclusion, the review covers in-depth conclusions on numerous aspects of formulation of drug-loaded vesicular system delivery across BBB, current marketed nasal devices, significant jeopardies, potential therapeutic aids, and current advancements followed by future perspectives.

Intranasal nanoparticulate delivery systems for neurodegenerative disorders: a review

Neurodegenerative diseases are a significant cause of mortality worldwide, and the blood-brain barrier (BBB) poses a significant challenge for drug delivery. An intranasal route is a prominent approach among the various methods to bypass the BBB. There are different pathways involved in intranasal drug delivery. The drawbacks of this method include mucociliary clearance, enzymatic degradation and poor drug permeation. Novel nanoformulations and intranasal drug-delivery devices offer promising solutions to overcome these challenges. Nanoformulations include polymeric nanoparticles, lipid-based nanoparticles, microspheres, liposomes and noisomes. Additionally, intranasal devices could be utilized to enhance drug-delivery efficacy. Therefore, intranasal drug-delivery systems show potential for treating neurodegenerative diseases through trigeminal or olfactory pathways, which can significantly improve patient outcomes.

Transnasal-brain delivery of nanomedicines for neurodegenerative diseases

Neurodegenerative diseases (NDs) have become a serious global health problem as the population ages. Traditionally, treatment strategies for NDs have included oral and intravenous administration; however, the blood–brain barrier (BBB) can prevent drugs from reaching the brain, rendering the treatment incomplete and the effect unsatisfactory. Additionally, the prolonged or excessive use of drugs that can cross the BBB can damage liver and kidney function. Recent studies have shown that nose-to-brain drug delivery can noninvasively bypass the BBB, allowing drugs to enter the brain through the olfactory or trigeminal nerve pathways; additionally, nanoparticle carriers can enhance drug delivery. This review introduces drug carrier nanoparticles for nose-to-brain delivery systems, compares the advantages and disadvantages of different nanoparticles, and discusses the factors influencing nose-to-brain nanomedicine delivery and enhancement strategies. We also summarize nose-to-brain delivery and nanomedicines for treating NDs, the current challenges of this approach, and the future promise of nanomedicine-based ND treatment.

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.

Cell-Penetrating Peptides as Valuable Tools for Nose-to-Brain Delivery of Biological Drugs

Due to their high specificity toward the target and their low toxicity, biological drugs have been successfully employed in a wide range of therapeutic areas. It is yet to be mentioned that biologics exhibit unfavorable pharmacokinetic properties, are susceptible to degradation by endogenous enzymes, and cannot penetrate biological barriers such as the blood-brain barrier (i.e., the major impediment to reaching the central nervous system (CNS)). Attempts to overcome these issues have been made by exploiting the intracerebroventricular and intrathecal routes of administration. The invasiveness and impracticality of these procedures has, however, prompted the development of novel drug delivery strategies including the intranasal route of administration. This represents a non-invasive way to achieve the CNS, reducing systemic exposure. Nonetheless, biotherapeutics strive to penetrate the nasal epithelium, raising the possibility that direct delivery to the nervous system may not be straightforward. To maximize the advantages of the intranasal route, new approaches have been proposed including the use of cell-penetrating peptides (CPPs) and CPP-functionalized nanosystems. This review aims at describing the most impactful attempts in using CPPs as carriers for the nose-to-brain delivery of biologics by analyzing their positive and negative aspects.

Single therapeutic dose of an antiviral UL29 siRNA swarm diminishes symptoms and viral load of mice infected intranasally with HSV-1

Herpes simplex virus type 1 (HSV-1) is a human pathogen that causes recurrent infections. Acyclovir-resistant strains exist and can cause severe complications, which are potentially untreatable with current therapies. We have developed siRNA swarms that target a 653 base pair long region of the essential HSV gene UL29. As per our previous results, the anti-UL29 siRNA swarm effectively inhibits the replication of circulating HSV strains and acyclovir-resistant HSV strains in vitro, while displaying a good safety profile. We investigated a single intranasal therapeutic dose of a siRNA swarm in mice, which were first inoculated intranasally with HSV-1 and given treatment 4 h later. We utilized a luciferase-expressing HSV-1 strain, which enabled daily follow-up of infection with in vivo imaging. Our results show that a single dose of a UL29-targeted siRNA swarm can inhibit the replication of HSV-1 in orofacial tissue, which was reflected in ex vivo HSV titers and HSV DNA copy numbers as well as by a decrease in a luciferase-derived signal. Furthermore, the treatment had a tendency to protect mice from severe clinical symptoms and delay the onset of the symptoms. These results support the development of antiviral siRNA swarms as a novel treatment for HSV-1 infections.

The Influence of Shape Parameters on Unidirectional Drug Release from 3D Printed Implants and Prediction of Release from Implants with Individualized Shapes

The local treatment of diseases by drug-eluting implants is a promising tool to enable successful therapy under potentially reduced systemic side effects. Especially, the highly flexible manufacturing technique of 3D printing provides the opportunity for the individualization of implant shapes adapted to the patient-specific anatomy. It can be assumed that variations in shape can strongly affect the released amounts of drug per time. This influence was investigated by performing drug release studies with model implants of different dimensions. For this purpose, bilayered model implants in a simplified geometrical shape in form of bilayered hollow cylinders were developed. The drug-loaded abluminal part consisted of a suitable polymer ratio of Eudragit® RS and RL, while the drug-free luminal part composed of polylactic acid served as a diffusion barrier. Implants with different heights and wall thicknesses were produced using an optimized 3D printing process, and drug release was determined in vitro. The area-to-volume ratio was identified as an important parameter influencing the fractional drug release from the implants. Based on the obtained results drug release from 3D printed implants with individual shapes exemplarily adapted to the frontal neo-ostial anatomy of three different patients was predicted and also tested in an independent set of experiments. The similarity of predicted and tested release profiles indicates the predictability of drug release from individualized implants for this particular drug-eluting system and could possibly facilitate the estimation of the performance of customized implants independent of individual in vitro testing of each implant geometry.

Topical Administration of Verapamil in Poly(ethylene glycol)-Modified Liposomes for Enhanced Sinonasal Tissue Residence in Chronic Rhinosinusitis: Ex Vivo and In Vivo Evaluations

Verapamil is a calcium channel blocker that holds promise for the therapy of chronic rhinosinusitis (CRS) with and without nasal polyps. The verapamil-induced side effects limit its tolerated dose via the oral route, underscoring the usefulness of localized intranasal administration. However, the challenge to intranasal administration is mucociliary clearance, which diminishes localized dose availability. To overcome this challenge, verapamil was loaded into a mucoadhesive cationic poly(ethylene glycol)-modified (PEGylated) liposomal carrier. Organotypic nasal explants were exposed to verapamil liposomes under flow conditions to mimic mucociliary clearance. The liposomes resulted in significantly higher tissue residence compared with the free verapamil control. These findings were further confirmed in vivo in C57BL/6 mice following intranasal administration. Liposomes significantly increased the accumulation of verapamil in nasal tissues compared with the control group. The developed tissue-retentive verapamil liposomal formulation is considered a promising intranasal delivery system for CRS therapy.

Optimising nasal powder drug delivery - Characterisation of the effect of excipients on drug absorption

The nasal physiology offers great potential for drug delivery but also poses specific challenges, among which the short residence time of applied drugs is one of the most striking. Formulating the drug as powder and using functional excipients are strategies to improve drug absorption. As nasal powders are still the minority on the market, there is a lack of data regarding their characterisation. This work aims at the characterisation of selected fillers (mannitol, microcrystalline cellulose) and mucoadhesives (pectin, chitosan glutamate, hydroxypropyl cellulose) with a set of methods that allows distinguishing their influences on dissolution and permeation of drugs, and on the viscoelasticity of the nasal fluid and thus the nasal residence time. Rheological studies revealed a potential of undissolved particles to prolong the residence time by increasing the elasticity of the nasal fluid. The assessment of drug dissolution showed a decreased dissolution rate in presence of insoluble or gelling excipients, which can be beneficial for drugs with low permeability, since embedded drugs are cleared slower than plain solutions. Drug permeation as important factor for the selection of excipients was evaluated with an RPMI 2650 cell model. Distinguishing the effects of excipients enables an effective selection of the most promising substances.

Biodistribution and Adjuvant Effect of an Intranasal Vaccine Based on Chitosan Nanoparticles against Paracoccidioidomycosis

Paracoccidioidomycosis (PCM) is a fungal infection caused by the thermodimorphic Paracoccidioides sp. PCM mainly affects the lungs, but, if it is not contained by the immune response, the disease can spread systemically. An immune response derived predominantly from Th1 and Th17 T cell subsets facilitates the elimination of Paracoccidioides cells. In the present work, we evaluated the biodistribution of a prototype vaccine based on the immunodominant and protective P. brasiliensis P10 peptide within chitosan nanoparticles in BALB/c mice infected with P. brasiliensis strain 18 (Pb18). The generated fluorescent (FITC or Cy5.5) or non-fluorescent chitosan nanoparticles ranged in diameter from 230 to 350 nm, and both displayed a Z potential of +20 mV. Most chitosan nanoparticles were found in the upper airway, with smaller amounts localized in the trachea and lungs. The nanoparticles complexed or associated with the P10 peptide were able to reduce the fungal load, and the use of the chitosan nanoparticles reduced the necessary number of doses to achieve fungal reduction. Both vaccines were able to induce a Th1 and Th17 immune response. These data demonstrates that the chitosan P10 nanoparticles are an excellent candidate vaccine for the treatment of PCM.

A Hematological and Histopathological Study on Diphenhydramine Nasal Nano-gel and Nano-emulgel for the Management of Allergic Rhinitis in Animal Model

The study aims to determine histamine efficacy on hematologic values in experimental animal model, under physiological and pathological conditions after inducing diphenhydramine-formulated nasal nano-gel/nano-emulgel in comparison with conventional nasal spray regime. In this study, we conducted experiment on New Zealand white male rabbits to prove our hypothesis that nasal diphenhydramine nano-gel and nano-emulgel can penetrate the nasal mucosa faster to show drug response and subside histaminic symptoms than market nasal spray (as reference). Blood samples from 48 New Zealand white male rabbits, under both experimental conditions (physiological and pathological) divided into four groups for each (n = 6) were investigated after inducing each dosage form intranasally. Hematologic parameters (WBCs, RBCs, HGB, PLTs, lymphocytes, monocytes, eosinophils, granulocyte counts) were analyzed in whole blood samples, collected at different time intervals. ANOVA and completely randomized design (CRD) were applied for statistical analysis. Histopathologically, nasal tissues of all groups were analyzed to see intramucosal surface changes. Data of descriptive statistics of hematological parameters analyzed at confidence level 95% showed that under physiological condition, hematological parameters of all groups were lying in normal range, whereas under pathological condition, low values of all hematological parameters were observed in all groups due to allergenic condition. The groups B (allergenic rabbits treated with formulated diphenhydramine nasal nano-gel) and C (allergenic rabbits treated with formulated diphenhydramine nasal nano-emulgel) have shown good changes in the treatment of allergenic rabbits as compared to group D (allergenic rabbits treated with formulated diphenhydramine nasal spray). The completely randomized ANOVA and Tukey HSD all-pairwise comparison tests of hematological parameters were applied that showed all groups in both studies were significantly different from each other. It was observed after histopathological study of nasal membrane tissues that change in mucosa has occurred due to the passage of drug. In summary, hematological profile and histopathological study have demonstrated the comparable results with conventional diphenhydramine nasal spray and formulated diphenhydramine nasal nano-gel/nano-emulgel which can exhibit considerable drug delivery dosage forms in the management of allergic rhinitis in animal model.

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.

Nasal residence time and rheological properties of a new bentonite-based thixotropic gel emulsion nasal spray - AM-301

OBJECTIVE

The present work provides characterization of rheological properties of a new bentonite-based thixotropic gel emulsion nasal spray (AM-301), its nasal residence time, distribution, safety and tolerability.

SIGNIFICANCE

The nasal epithelium is a portal of entry for allergens and primary infection by airborne pathogens. Non-pharmacological interventions, which enhance physical and biological barriers, protect against allergens and pathogens without drug-related side effects. AM-301 has shown promising efficacy and safety in the nasal epithelium against viruses (in vitro) and pollen (clinical).

METHODS

Technical part (i) spray characterization was performed with a validated droplet size distribution method; evaluation of the rheological properties of the formulation was performed by a validated amplitude sweep method and a validated oscillation, rotation, oscillation; Clinical part (ii) nasal and oropharyngeal endoscopy were used to provide a semi-quantitative evaluation of distribution and residence time of fluorescein-labelled AM-301 in the nose and oropharynx of healthy volunteers; (iii) tolerability and safety.

RESULTS

(i) The non-Newtonian rheological properties of the formulation allow AM-301 to be sprayed and then to revert to a gel to prevent run-off from the nasal cavity; (ii) the formulation remains on the inferior turbinate, septum and oropharynx of volunteers for up to 210 min and on the middle turbinate for up to 60 min; two nasal sprays provide no substantial benefit over a single application with regards to coverage or retention; (iii) the spray is well tolerated.

CONCLUSIONS

Single dose spray delivery of AM-301 provides extended coverage of the nasal mucosa up to the inferior turbinates.

Improving the Emergency Department Management of Sickle Cell Vaso-Occlusive Pain Crisis: The Role and Options of Sublingual and Intranasally Administered Analgesia

Vaso-occlusive crisis (VOC), characterized by periods of excruciating pain is the most common clinical manifestation of sickle cell disease (SCD), often resulting in emergency room presentation. These patients often experience long wait times in the emergency department before receiving their first dose of analgesia. This delay results from the complexities of the emergency care system. Using the intranasal or sublingual approach to administering analgesia to SCD patients with VOC offers a fast, safe, noninvasive, atraumatic, and easily accessible route of administration which could reduce the time to first dose of analgesia. With the evolving advances in the development and delivery of analgesic medications, providers should be conversant with the nuances of intranasal and sublingual analgesia in the management of acute vaso-occlusive pain crisis. This review explores the pharmacokinetic profiles, dosages, and administration of intranasal and sublingual analgesics with relevance to the SCD population.

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.

Delivery of Dihydroergotamine Mesylate to the Upper Nasal Space for the Acute Treatment of Migraine: Technology in Action

Oral tablets account for the majority of medications used to acutely treat migraine, but relief can be limited by their rates of dissolution and absorption. The nose is an attractive alternative route of drug delivery since it provides patient convenience of at-home use, gastrointestinal (GI) avoidance, and rapid absorption of drugs into systemic circulation because of its large surface area. However, the site of drug deposition within the nasal cavity should be considered since it can influence drug absorption. Traditional nasal devices have been shown to target drug delivery to the lower nasal space where epithelium is not best-suited for drug absorption and where there is an increased likelihood of drug clearance due to nasal drip, swallowing, or mucociliary clearance, potentially resulting in variable absorption and suboptimal efficacy. Alternatively, the upper nasal space (UNS) offers a permeable, richly vascularized epithelium with a decreased likelihood of drug loss or clearance due to the anatomy of this area. Traditional nasal pumps deposit <5% of active drug into the UNS because of the nasal cavity's complex architecture. A new technology, Precision Olfactory Delivery (POD^®), is a handheld, manually actuated, propellant-powered, administration device that delivers drug specifically to the UNS. A dihydroergotamine (DHE) mesylate product, INP104, utilizes POD technology to deliver drug to the UNS for the acute treatment of migraine. Results from clinical studies of INP104 demonstrate a favorable pharmacokinetic profile, consistent and predictable dosing, rapid systemic levels known to be effective (similar to other DHE mesylate clinical programs), safety and tolerability on the upper nasal mucosa, and high patient acceptance. POD technology may have the potential to overcome the limitations of traditional nasal delivery systems, while utilizing the nasal delivery benefits of GI tract avoidance, rapid onset, patient convenience, and ease of use.

The Objective Assessment of dry Nose

Background

Dry nose (DN) is a common symptom in both patients with rhinitis and healthy individuals; however, it is often overlooked.

Objective

This study aimed to investigate the characteristics of and propose objective diagnostic criteria for DN.

Methods

This study was conducted from December, 2018 to October, 2021. Patients with complaints of a dry nasal cavity and normal controls were recruited consecutively from the allergy-rhinology outpatient clinic of Beijing TongRen Hospital. Questionnaires were completed by each participant during recruitment to record demographic data. DN test strips were used to evaluate the severity of DN. The length of the strip was recorded at 30 s, 1 min, 2 min, 3 min, 4 min, and 5 min, respectively. Nasal secretions were collected on sponges and allergic status was assessed based on serum sage levels.

Results

Twenty (13 men and 7 women) patients with DN and 100 (47 men and 53 women) controls were recruited for the study. The participants’ ages ranged from 23 to 73 years (mean  =  47.7 years). Nine of the 20 DN patients were diagnosed with vasomotor rhinitis. The weight of the sponges of DN patients was significantly lower than that of controls. At the last time point (5 min), the strips in the control group were significantly longer than those in the DN group. The reference range of 30 s, 1 min, 2 min, 3 min, 4 min, and 5 min of controls was 3.0 mm, 6.0 mm, 10.9 mm, 13.2 mm, 16.8 mm, and 17.0 mm, respectively.

Conclusions

Our study indicated that the strip length less than 17.0 mm at 5 min is a valuable reference for the diagnostic of DN in Beijing.

Development of In Vitro Evaluation System for Assessing Drug Dissolution Considering Physiological Environment in Nasal Cavity

Estimating the dissolution behavior of a solid in the nasal mucus is challenging for solid dosage forms designed for the nasal application as the solid dissolves into nasal mucus and permeates through the mucosa. In the current study, the dissolution behavior of powders in the artificial nasal fluid was investigated using a 3D-printed chamber system to establish in vitro evaluation system for the dissolution of solid formulations that can simulate the intranasal environment in vivo. The dissolution rates of the five model drugs correlated with their solubility (r2 = 0.956, p < 0.01). The permeation rate of drugs across the Calu-3 cell layers after powder application depends on the membrane permeability of the drug. An analysis of membrane permeability considering the dissolution of powders showed the possibility of characterizing whether the drug in the powder was dissolution-limited or permeation-limited. This suggests that critical information can be obtained to understand which mechanism is more effective for the improvement of drug absorption from powders. This study indicates that the elucidation of drug dissolution behavior into nasal mucus is an important factor for the formulation of nasal powders and that the in vitro system developed could be a useful tool.

Intranasal delivery of a synthetic Entamoeba histolytica vaccine containing adjuvant (LecA + GLA-3M-052 liposomes): in vitro characterization

Amebiasis, a disease caused by the parasite Entamoeba histolytica, is estimated to cause millions of infections and at least 55,000 deaths globally each year. With no vaccine currently available, there is an urgent need for an accessible means of stimulating protective mucosal immunity. The objective of this study was to characterize the nasal spray of a novel amebiasis vaccine candidate from a syringe-based liquid atomization device, the Teleflex MAD Nasal™, in both adult and infant nasal airways. Human ergonomic testing was completed to determine realistic actuation parameters. Spray pattern, plume geometry, and droplet size distribution were measured to evaluate reproducibility of free plume characteristics. The Alberta Idealized Nasal Inlet (AINI) and three realistic infant nasal airways were used to determine the in vitro deposition profile in adult and infant airways, respectively. Collectively, in vitro results demonstrated the feasibility of delivering the vaccine candidate to target sites within the nasal airways. Penetration through the nasal airways that could lead to deposition in the lungs was below the limit of quantification for both adult and infant geometries, indicating a low likelihood of adverse events due to lung exposure. These results support continued investigation of intranasal delivery of the synthetic Entamoeba histolytica vaccine.

LNIT-Local nasal immunotherapy in allergic rhinitis: revisited evidence and perspectives

PURPOSE OF REVIEW

Allergen immunotherapy (AIT) is a personalized treatment approach for the allergic airway disease. The most common routes of administration are subcutaneous and sublingual. Local nasal immunotherapy (LNIT) presents another alternative route for allergen desensitization. Nasal mucosa is the first entry site of pathogens and numerous lymphoid organs are located in this area, making LNIT a favorable method for triggering immune tolerance. LNIT has shown promising results in reducing symptoms and medication use in allergic rhinitis patients. Over time, difficulties in dosing adjustments have made this method less popular. Recent advances in intranasal drug delivery systems warrant re-examination of LNIT as a viable option for the treatment of the allergic airway disease.

RECENT FINDINGS

The scope of the review includes evidences of LNIT in human trials including comparison with placebo and conventional method of immunotherapy. Recent articles regarding the mechanism of LNIT and the challenges of intranasal drug delivery are reviewed. Advances in the LNIT delivery system which have overcome previous limitations demonstrate promising effects.

SUMMARY

LNIT presents a judicious alternative for noninjection AIT. The evidences from previous clinical trials and the novel improvement of drug delivery system will lead into the future allergen vaccine production.

Formulation and In Vitro Characterization of a Vacuum-Dried Drug–Polymer Thin Film for Intranasal Application

Intranasal drug applications show significant therapeutic potential for diverse pharmaceutical modalities. Because the formulation applied to the nasal cavity is discharged to the pharyngeal side by mucociliary clearance, the formulation should be dissolved effectively in a limited amount of mucus within its retention time in the nasal cavity. In this study, to develop novel formulations with improved dissolution behavior and compatibility with the intranasal environment, a thin-film formulation including drug and polymer was prepared using a vacuum-drying method. The poorly water-soluble drugs ketoprofen, flurbiprofen, ibuprofen, and loxoprofen were dissolved in a solvent comprising water and methanol, and evaporated to obtain a thin film. Physical analyses using differential scanning calorimetry (DSC), powder X-ray diffraction analysis (PXRD), and scanning electron microscopy SEM revealed that the formulations were amorphized in the film. The dissolution behavior of the drugs was investigated using an in vitro evaluation system that mimicked the intranasal physiological environment. The amorphization of drugs formulated with polymers into thin films using the vacuum-drying method improved the dissolution rate in artificial nasal fluid. Therefore, the thin film developed in this study can be safely and effectively used for intranasal drug application.