Brain targeted intranasal in-situ gelling spray of paroxetine: Formulation, characterization and in-vivo evaluation"

The nasal route for nose-to-brain drug delivery: advanced nasal formulations for CNS disorders

INTRODUCTION

The nasal route offers a feasible alternative to oral and/or parenteral administration, providing a noninvasive route to achieve nose-to-brain drug delivery involving the olfactory and trigeminal nerves, and facilitating local or systemic drug action. Conventional liquid nasal dosage forms have not managed to bridge the gaps of precise dosing and targeted central nervous system (CNS) delivery, while more sophisticated formulation approaches are being explored for brain targeting, aiming to enhance bioavailability and therapeutic efficacy.

AREAS COVERED

This review focuses on preclinical and clinical evaluation of microemulsions, in-situ gels, nasal powders, and nanocarrier-based formulations. Key pharmacokinetic and pharmacodynamic findings are discussed to evaluate their potential and limitations in improving drug bioavailability and CNS targeting. The existing regulatory framework for approval of products for nose-to-brain drug delivery is also addressed and relative hurdles are discussed.

EXPERT OPINION

While nasal drug delivery holds great promise for CNS therapeutics, key challenges remain, including formulation stability, mucosal permeability, patient adherence. Future research should prioritize improving targeting efficiency, overcoming mucociliary clearance, developing user-friendly pharmaceutical products. Personalized medicine and smart delivery systems could further enhance drug targeting and minimize side effects. Continued research and regulatory advancements are essential to fully realize nasal delivery's perspective in CNS therapeutics.

Nose-to-Brain Delivery of Chitosan-Grafted Leciplexes for Promoting the Bioavailability and Antidepressant Efficacy of Mirtazapine: In Vitro Assessment and Animal Studies

Background/Objectives: Mirtazapine (MRZ) is a psychotropic drug prescribed to manage serious sorts of depression. By virtue of its extensive initial-pass metabolic process with poor water solubility, the ultimate bioavailability when taken orally is a mere 50%, necessitating repeated administration. The current inquiry intended to fabricate nose-to-brain chitosan-grafted cationic leciplexes of MRZ (CS-MRZ-LPX) to improve its pharmacokinetic weaknesses and boost the pharmacodynamics aspects. Methods: Primarily, MRZ-loaded leciplexes (MRZ-LPXs) were fabricated and tailored employing a central composite design (CCD). Vesicle diameter size (VS), entrapment efficiency (EE %), cumulative MRZ release percentage (CMRZR %), and total quantity penetrating after twenty-four hours (Q24) were the four parameters assessed. Then, the determined optimum formulation was coated with chitosan (CS-MRZ-LPX) and utilized in pharmacodynamics investigations and in vivo biologic distribution studies in Wistar male rats. Results: The customized MRZ-LPX formulation had a diameter size of 186.2 ± 3.5 nm and drug EE of 45.86 ± 0.76%. Also, the tailored MRZ-LPX formulation had a cumulative amount of MRZ released of 76.66 ± 3.06% and the total Q24 permeated was 383.23 ± 13.08 µg/cm2. Intranasal delivery of the tailored CS-MRZ-LPX revealed notably superior pharmacokinetic attributes inside the brain and circulation compared to the orally administered MRZ suspension and the intranasal free drug suspension (p < 0.05); the relative bioavailability was 370.9% and 385.6% for plasma and brain, respectively. Pharmacodynamics' and immunohistopathological evaluations proved that optimum intranasal CS-MRZ-LPX boosted antidepressant activity compared to the oral and free nasal drug administration. Conclusions: CS-MRZ-LPX tailored formulation can potentially be regarded as a prospective nano platform to boost bioavailability and enhance pharmacodynamics efficacy. Ultimately, intranasal CS-MRZ-LPX can be considered a promising avenue for MRZ targeted brain delivery as an antidepressant.

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

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

Breath and Beyond: Advances in Nanomedicine for Oral and Intranasal Aerosol Drug Delivery

Designing and standardizing drug formulations are crucial for ensuring the safety and efficacy of medications. Nanomedicine utilizes nano drug delivery systems and advanced nanodevices to address numerous critical medical challenges. Currently, oral and intranasal aerosol drug delivery (OIADD) is the primary method for treating respiratory diseases worldwide. With advancements in disease understanding and the development of aerosolized nano drug delivery systems, the application of OIADD has exceeded its traditional boundaries, demonstrating significant potential in the treatment of non-respiratory conditions as well. This study provides a comprehensive overview of the applications of oral and intranasal aerosol formulations in disease treatment. It examines the key challenges limiting the development of nanomedicines in drug delivery systems, formulation processes, and aerosol devices and explores the latest advancements in these areas. This review aims to offer valuable insights to researchers involved in the development of aerosol delivery platforms.

Review of Intranasal Active Pharmaceutical Ingredient Delivery Systems

In recent decades, there has been an increased interest in the development of intranasal delivery systems for active pharmaceutical ingredients (APIs) not only for treating local nasal diseases but also for treating systemic diseases, central nervous system (CNS) disorders, and vaccine delivery. The nasal cavity possesses a unique set of anatomical characteristics for delivering active pharmaceutical ingredients, but there are several limitations that recent research in the field of the intranasal administration of APIs aims to overcome. For the effective delivery of nasal preparations, active pharmaceutical ingredients are incorporated into various micro- and nanosystems. Some of the most commonly encountered API delivery systems in the scientific literature include liposomal systems, polymer particles with mucoadhesive properties, in situ gels, nano- and microemulsions, and solid lipid particles. This article provides a review of research on the development of nasal preparations for treating local nasal cavity diseases (in particular, for antibiotic delivery), systemic diseases (analgesics, drugs for cardiovascular diseases, antiviral and antiemetic drugs), CNS disorders (Alzheimer's disease, Parkinson's disease, epilepsy, schizophrenia, depression), and vaccine delivery. The literature data show that active research is underway to reformulate drugs of various pharmacotherapeutic groups into a nasal form.

Versatile Nanoparticulate Systems as a Prosperous Platform for Targeted Nose-Brain Drug Delivery

The intranasal route has proven to be a reliable and promising route for delivering therapeutics to the central nervous system (CNS), averting the blood-brain barrier (BBB) and avoiding extensive first-pass metabolism of some drugs, with minimal systemic exposure. This is considered to be the main problem associated with other routes of drug delivery such as oral, parenteral, and transdermal, among other administration methods. The intranasal route maximizes drug bioavailability, particularly those susceptible to enzymatic degradation such as peptides and proteins. This review will stipulate an overview of the intranasal route as a channel for drug delivery, including its benefits and drawbacks, as well as different mechanisms of CNS drug targeting using nanoparticulate drug delivery systems devices; it also focuses on pharmaceutical dosage forms such as drops, sprays, or gels via the nasal route comprising different polymers, absorption promoters, CNS ligands, and permeation enhancers.

Recent Advances in Intranasal Administration for Brain-Targeting Delivery: A Comprehensive Review of Lipid-Based Nanoparticles and Stimuli-Responsive Gel Formulations

Addressing disorders related to the central nervous system (CNS) remains a complex challenge because of the presence of the blood-brain barrier (BBB), which restricts the entry of external substances into the brain tissue. Consequently, finding ways to overcome the limited therapeutic effect imposed by the BBB has become a central goal in advancing delivery systems targeted to the brain. In this context, the intranasal route has emerged as a promising solution for delivering treatments directly from the nose to the brain through the olfactory and trigeminal nerve pathways and thus, bypassing the BBB. The use of lipid-based nanoparticles, including nano/microemulsions, liposomes, solid lipid nanoparticles, and nanostructured lipid carriers, has shown promise in enhancing the efficiency of nose-to-brain delivery. These nanoparticles facilitate drug absorption from the nasal membrane. Additionally, the in situ gel (ISG) system has gained attention owing to its ability to extend the retention time of administered formulations within the nasal cavity. When combined with lipid-based nanoparticles, the ISG system creates a synergistic effect, further enhancing the overall effectiveness of brain-targeted delivery strategies. This comprehensive review provides a thorough investigation of intranasal administration. It delves into the strengths and limitations of this specific delivery route by considering the anatomical complexities and influential factors that play a role during dosing. Furthermore, this study introduces strategic approaches for incorporating nanoparticles and ISG delivery within the framework of intranasal applications. Finally, the review provides recent information on approved products and the clinical trial status of products related to intranasal administration, along with the inclusion of quality-by-design-related insights.

Nucleic acid-based therapeutics for the treatment of central nervous system disorders

Nucleic acid-based therapeutics (NBTs) are an emerging class of drugs with potential for the treatment of a wide range of central nervous system conditions. To date, pertaining to CNS indications, there are two commercially available NBTs and a large number of ongoing clinical trials. However, these NBTs are applied directly to the brain due to very low blood brain barrier permeability. In this review, we outline recent advances in chemical modifications of NBTs and NBT delivery techniques intended to promote brain exposure, efficacy, and possible future systemic application.

Development of Atomoxetine-Loaded NLC In Situ Gel for Nose-to-Brain Delivery: Optimization, In Vitro, and Preclinical Evaluation

The present study investigates the brain-targeted efficiency of atomoxetine (AXT)-loaded nanostructured lipid carrier (NLC)-laden thermosensitive in situ gel after intranasal administration. AXT-NLC was prepared by the melt emulsification ultrasonication method and optimized using the Box-Behnken design (BBD). The optimized formulation (AXT-NLC) exhibited particle size PDI, zeta potential, and entrapment efficiency (EE) of 108 nm, 0.271, -42.3 mV, and 84.12%, respectively. The morphology of AXT-NLC was found to be spherical, as confirmed by SEM analysis. DSC results displayed that the AXT was encapsulated within the NLC matrix. Further, optimized NLC (AXT-NLC13) was incorporated into a thermosensitive in situ gel using poloxamer 407 and carbopol gelling agent and evaluated for different parameters. The optimized in situ gel (AXT-NLC13G4) formulation showed excellent viscosity (2532 ± 18 Cps) at 37 °C and formed the gel at 28-34 °C. AXT-NLC13-G4 showed a sustained release of AXT (92.89 ± 3.98% in 12 h) compared to pure AXT (95.47 ± 2.76% in 4 h). The permeation flux through goat nasal mucosa of AXT from pure AXT and AXT-NLC13-G4 was 504.37 µg/cm²·h and 232.41 µg/cm²·h, respectively. AXT-NLC13-G4 intranasally displayed significantly higher absolute bioavailability of AXT (1.59-fold higher) than intravenous administration. AXT-NLC13-G4 intranasally showed 51.91% higher BTP than pure AXT (28.64%) when administered via the same route (intranasally). AXT-NLC13-G4 showed significantly higher BTE (207.92%) than pure AXT (140.14%) when administered intranasally, confirming that a high amount of the AXT reached the brain. With the disrupted performance induced by L-methionine, the AXT-NLC13-G4 showed significantly (p < 0.05) better activity than pure AXT as well as donepezil (standard). The finding concluded that NLC in situ gel is a novel carrier of AXT for improvement of brain delivery by the intranasal route and requires further investigation for more justification.

Intranasal Polymeric and Lipid-Based Nanocarriers for CNS Drug Delivery

Nanomedicine is currently focused on the design and development of nanocarriers that enhance drug delivery to the brain to address unmet clinical needs for treating neuropsychiatric disorders and neurological diseases. Polymer and lipid-based drug carriers are advantageous for delivery to the central nervous system (CNS) due to their safety profiles, drug-loading capacity, and controlled-release properties. Polymer and lipid-based nanoparticles (NPs) are reported to penetrate the blood–brain barrier (BBB) and have been extensively assessed in in vitro and animal models of glioblastoma, epilepsy, and neurodegenerative disease. Since approval by the Food and Drug Administration (FDA) of intranasal esketamine for treatment of major depressive disorder, intranasal administration has emerged as an attractive route to bypass the BBB for drug delivery to the CNS. NPs can be specifically designed for intranasal administration by tailoring their size and coating with mucoadhesive agents or other moieties that promote transport across the nasal mucosa. In this review, unique characteristics of polymeric and lipid-based nanocarriers desirable for drug delivery to the brain are explored in addition to their potential for drug repurposing for the treatment of CNS disorders. Progress in intranasal drug delivery using polymeric and lipid-based nanostructures for the development of treatments of various neurological diseases are also described.

In vitro and ex vivo experimental models for evaluation of intranasal systemic drug delivery as well as direct nose-to-brain drug delivery

The intranasal route of administration provides a noninvasive method to deliver drugs into the systemic circulation and/or directly into the brain. Direct nose-to-brain drug delivery offers the possibility to treat central nervous system diseases more effectively, as it can evade the blood-brain barrier. In vitro and ex vivo intranasal models provide a means to investigate physiological and pharmaceutical factors that could play a role in drug delivery across the nasal epithelium as well as to determine the mechanisms involved in drug absorption from the nose. The development and implementation of cost-effective pharmacokinetic models for intranasal drug delivery with good in vitro-in vivo correlation can accelerate pharmaceutical drug product development and improve economic and ecological aspects by reducing the time and costs spent on animal studies. Special considerations should be made with regard to the purpose of the in vitro/ex vivo study, namely, whether it is intended to predict systemic or brain delivery, source and site of tissue or cell sampling, viability window of selected model, and the experimental setup of diffusion chambers. The type of model implemented should suit the relevant needs and requirements of the project, researcher, and interlaboratory. This review aims to provide an overview of in vitro and ex vivo models that have been developed to study intranasal and direct nose-to-brain drug delivery.

Formulation considerations for improving intranasal delivery of CNS acting therapeutics

One of the principal impediments for the treatment of neurological conditions is the lack of ability of most of the medicinal agents to evade the blood–brain barrier. Among all the novel approaches to bypass the blood–brain barrier, nose to brain transport is the most patient compliant, non-invasive and effective approach. It directly transports drugs to the CNS via the trigeminal and olfactory nerves present in the nasal cavity. This review article focuses on anatomy and physiology of nasal cavity, potential of intranasal drug delivery, mechanisms of drug transport to brain, its advantages and limitations, novel intranasal formulations, marketed products, factors affecting nose to brain transport, formulation consideration of intranasal products and the future perspectives of CNS targeting via intranasal drug administration.

Evaluation of Recent Intranasal Drug Delivery Systems to the Central Nervous System

Neurological diseases continue to increase in prevalence worldwide. Combined with the lack of modifiable risk factors or strongly efficacious therapies, these disorders pose a significant and growing burden on healthcare systems and societies. The development of neuroprotective or curative therapies is limited by a variety of factors, but none more than the highly selective blood-brain barrier. Intranasal administration can bypass this barrier completely and allow direct access to brain tissues, enabling a large number of potential new therapies ranging from bioactive peptides to stem cells. Current research indicates that merely administering simple solutions is inefficient and may limit therapeutic success. While many therapies can be delivered to some degree without carrier molecules or significant modification, a growing body of research has indicated several methods of improving the safety and efficacy of this administration route, such as nasal permeability enhancers, gelling agents, or nanocarrier formulations. This review shall discuss promising delivery systems and their role in expanding the clinical efficacy of this novel administration route. Optimization of intranasal administration will be crucial as novel therapies continue to be studied in clinical trials and approved to meet the growing demand for the treatment of patients with neurological diseases.

Advances in the Prophylaxis of Respiratory Infections by the Nasal and the Oromucosal Route: Relevance to the Fight with the SARS-CoV-2 Pandemic

In this time of COVID-19 pandemic, the strategies for prevention of the infection are a primary concern. Looking more globally on the subject and acknowledging the high degree of misuse of protective face masks from the population, we focused this review on alternative pharmaceutical developments eligible for self-defense against respiratory infections. In particular, the attention herein is directed to the nasal and oromucosal formulations intended to boost the local immunity, neutralize or mechanically "trap" the pathogens at the site of entry (nose or mouth). The current work presents a critical review of the contemporary methods of immune- and chemoprophylaxis and their suitability and applicability in topical mucosal dosage forms for SARS-CoV-2 prophylaxis.

Biomaterials for Drugs Nose-Brain Transport: A New Therapeutic Approach for Neurological Diseases

In the last years, neurological diseases have resulted in a global health issue, representing the first cause of disability worldwide. Current therapeutic approaches against neurological disorders include oral, topical, or intravenous administration of drugs and more invasive techniques such as surgery and brain implants. Unfortunately, at present, there are no fully effective treatments against neurodegenerative diseases, because they are not associated with a regeneration of the neural tissue but rather act on slowing the neurodegenerative process. The main limitation of central nervous system therapeutics is related to their delivery to the nervous system in therapeutic quantities due to the presence of the blood-brain barrier. In this regard, recently, the intranasal route has emerged as a promising administration site for central nervous system therapeutics since it provides a direct connection to the central nervous system, avoiding the passage through the blood-brain barrier, consequently increasing drug cerebral bioavailability. This review provides an overview of the nose-to-brain route: first, we summarize the anatomy of this route, focusing on the neural mechanisms responsible for the delivery of central nervous system therapeutics to the brain, and then we discuss the recent advances made on the design of intranasal drug delivery systems of central nervous system therapeutics to the brain, focusing in particular on stimuli-responsive hydrogels.