In situ gelling nanosuspension as an advanced platform for fluticasone propionate nasal delivery

Advances in nano-based drug delivery systems for the management of cytokine influx-mediated inflammation in lung diseases

Asthma, lung cancer, cystic fibrosis, tuberculosis, acute respiratory distress syndrome, chronic obstructive pulmonary disease, and COVID-19 are few examples of inflammatory lung conditions that cause cytokine release syndrome. It can initiate a widespread inflammatory response and may activate several inflammatory pathways that cause multiple organ failures leading to increased number of deaths and increased prevalence rates around the world. Nanotechnology-based therapeutic modalities such as nanoparticles, liposomes, nanosuspension, monoclonal antibodies, and vaccines can be used in the effective treatment of inflammatory lung diseases at both cellular and molecular levels. This would also help significantly in the reduction of patient mortality. Therefore, nanotechnology could be a potent platform for repurposing current medications in the treatment of inflammatory lung diseases. The aim and approach of this article are to highlight the clinical manifestations of cytokine storm in inflammatory lung diseases along with the advances and potential applications of nanotechnology-based therapeutics in the management of cytokine storm. Further in-depth studies are required to understand the molecular pathophysiology, and how nanotechnology-based therapeutics can help to effectively combat this problem.

An eosinophil peroxidase activity assay accurately predicts eosinophilic chronic rhinosinusitis

BACKGROUND

A definitive diagnosis of eosinophilic chronic rhinosinusitis (eCRS) requires invasive surgical tissue sampling and histologic enumeration of intact eosinophils. Eosinophil peroxidase (EPX) is an accurate biomarker of sinonasal tissue eosinophilia in CRS regardless of polyp status. A less invasive and rapid method that accurately identifies tissue eosinophilia would be of great benefit to patients.

OBJECTIVE

We sought to evaluate a new clinical tool that uses a nasal swab and colorimetric EPX activity assay to predict a diagnosis of eCRS.

METHODS

A prospective, observational cohort study was conducted using nasal swabs and sinonasal tissue biopsies obtained from patients with CRS electing endoscopic sinus surgery. Patients were classified as non-eCRS (n = 19) and eCRS (n = 35) on the basis of pathologically determined eosinophil counts of less than 10 or greater than or equal to 10 eosinophils/HPF, respectively. Swab-deposited EPX activity was measured and compared with tissue eosinophil counts, EPX levels, and CRS-specific disease metrics.

RESULTS

EPX activity was significantly increased in patients with eCRS than in patients without eCRS (P < .0001). With a relative absorbance unit cutoff value of greater than or equal to 0.80, the assay demonstrated high sensitivity (85.7%) and moderate specificity (79.0%) for confirming eCRS. Spearman correlations between EPX activity and tissue eosinophil counts (rs = 0.424), EPX levels (rs = 0.503), and Lund-Kennedy endoscopy scores (rs = 0.440) in eCRS were significant (P < .05).

CONCLUSIONS

This investigation evaluates a nasal swab sampling method and EPX activity assay that accurately confirms eCRS. This method could potentially address the unmet need to identify sinonasal tissue eosinophilia at the point-of-care, as well as to longitudinally monitor eosinophil activity and treatment response.

Development of an Antiviral Ion-Activated In Situ Gel Containing 18β-Glycyrrhetinic Acid: A Promising Alternative against Respiratory Syncytial Virus

The human respiratory syncytial virus (hRSV) is a major cause of serious lower respiratory infections and poses a considerable risk to public health globally. Only a few treatments are currently used to treat RSV infections, and there is no RSV vaccination. Therefore, the need for clinically applicable, affordable, and safe RSV prevention and treatment solutions is urgent. In this study, an ion-activated in situ gelling formulation containing the broad-spectrum antiviral 18β-glycyrrhetinic acid (GA) was developed for its antiviral effect on RSV. In this context, pH, mechanical characteristics, ex vivo mucoadhesive strength, in vitro drug release pattern, sprayability, drug content, and stability were all examined. Rheological characteristics were also tested using in vitro gelation capacity and rheological synergism tests. Finally, the cytotoxic and antiviral activities of the optimized in situ gelling formulation on RSV cultured in the human laryngeal epidermoid carcinoma (HEp-2) cell line were evaluated. In conclusion, the optimized formulation prepared with a combination of 0.5% w/w gellan gum and 0.5% w/w sodium carboxymethylcellulose demonstrated good gelation capacity and sprayability (weight deviation between the first day of the experiment (T0) and the last day of the experiment (T14) was 0.34%), desired rheological synergism (mucoadhesive force (Fb): 9.53 Pa), mechanical characteristics (adhesiveness: 0.300 ± 0.05 mJ), ex vivo bioadhesion force (19.67 ± 1.90 g), drug content uniformity (RSD%: 0.494), and sustained drug release over a period of 6 h (24.56% ± 0.49). The optimized formulation demonstrated strong anti-hRSV activity (simultaneous half maximal effective concentration (EC50) = 0.05 µg/mL; selectivity index (SI) = 306; pre-infection EC50 = 0.154 µg/mL; SI = 100), which was significantly higher than that of ribavirin (EC50 = 4.189 µg/mL; SI = 28) used as a positive control against hRSV, according to the results of the antiviral activity test. In conclusion, this study showed that nasal in situ gelling spray can prevent viral infection and replication by directly inhibiting viral entry or modulating viral replication.

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

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

Thermoreversible Carbamazepine In Situ Gel for Intranasal Delivery: Development and In Vitro, Ex Vivo Evaluation

Over the past decade, intranasal (IN) delivery has been gaining attention as an alternative approach to conventional drug delivery routes targeting the brain. Carbamazepine (CBZ) is available as an orally ingestible formulation. The present study aims to develop a thermoreversible in situ gelling system for delivering CBZ via IN route. A cold method of synthesis has been used to tailor and optimize the thermoreversible gel composition, using poloxamer 407 (P407) (15-20% w/v) and iota carrageenan (ɩ-Cg) (0.15-0.25% w/v). The developed in situ gel showed gelation temperatures (28-33°C), pH (4.5-6.5), rheological properties (pseudoplastic, shear thinning), and mucoadhesive strength (1755.78-2495.05 dyne/cm²). The in vitro release study has shown sustained release behavior (24 h) for gel, containing significant retardation of CBZ release. The release kinetics fit to the Korsmeyer-Peppas model, suggesting the non-Fickian diffusion type controlled release behavior. Ex vivo permeation through goat nasal mucosa showed sustained release from the gel containing 18% P407 with the highest cumulative drug permeated (243.94 µg/cm²) and a permeation flux of 10.16 µg/cm²/h. After treatment with CBZ in situ gel, the barrier function of nasal mucosa remained unaffected. Permeation through goat nasal mucosa using in situ gel has demonstrated a harmless nasal delivery, which can provide a new dimension to deliver CBZ directly to the brain bypassing the blood-brain barrier.