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

Uniform Spray Dried Loxapine Microparticles Potentially for Nasal Delivery: Exploring Discriminatory In Vitro Release Evaluation Methods

This study aimed to develop suitable in vitro evaluation methods for the release behavior of nasal powders (NPs). We synthesized a range of standardized microparticles with adjustable size and morphology by co-spray-drying loxapine succinate (LOX) and gelatin (GEL) using an ethanol/water solvent mixture in a self-designed micro-fluidic jet spray dryer (MFJSD). The influence of the LOX/GEL mass ratio and solvent composition on particle characteristics, including size, morphology, and crystalline properties, was systematically investigated. In vitro release profiles of NPs were thoroughly assessed across different release medium, apparatus, and membranes. The modified Transwell® system, utilizing simulated nasal electrolyte solution (SNES) as the release medium, was identified as the most effective in distinguishing the performance of microparticles with diverse attributes. Furthermore, the impact of particle size, morphology, and crystalline properties on in vitro release profiles was discussed. This research presents a robust methodology for the in vitro evaluation of NPs release profiles and provides a practical approach for the rational fabrication of high-quality NPs products.

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.

In Situ Thermosensitive Mucoadhesive Nasal Gel Containing Sumatriptan: In Vitro and Ex Vivo Evaluations

The aim of this study was to develop a thermosensitive mucoadhesive (MA) in situ nasal gel for sumatriptan. A 3D response surface methodology (Design of Expert version 11) was employed to formulate nine different formulations. The Pluronic F-127 concentration (X1) and chitosan concentration (X2) were selected as independent factors. The formulas were studied in terms of pH, clarity, drug content, gelation temperature, gelation time, gel strength, MA strength, viscosity, % release after 5 h, and release kinetics. The optimized formulas were studied for % permeated after 5 h and stability in addition to previous tests. The study of the stability of the optimized formula was performed under accelerated conditions (40 ± 2 °C, 75 ± 5% RH) for 3 months. The outcomes of the optimized formula were a clear gel with a gelation temperature of 33 °C and a reasonable gelation time of less than one minute, and the release and permeation during 5 h were 40% and 50%, respectively. The formulated gel decreased the mucociliary clearance (MCC) and thus increased the retention time in the nasal cavity, resulting in enhancing SMT absorption, which could improve the drug efficacy.

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

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

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

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

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

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

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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