Combination of PEGylation and Cationization on Phospholipid-Coated Cyclosporine Nanosuspensions for Enhanced Ocular Drug Delivery

Breaking barriers in ocular drug delivery for Uveitis: Advanced drug delivery systems, challenges and future prospects

Uveitis is inflammation of the uvea, the middle layer of the eye which comprises of iris, ciliary body and choroid. Complications associated with uveitis include chronic pain, vision impairment and even blindness if not treated adequately. Conventional treatments for uveitis include immunosuppressive medications such as corticosteroids and biologics, which present challenges of low bioavailability due to complex anatomical structure of eye, rapid drug elimination, enzymatic degradation and the blood-retinal barrier. Consequently, they require frequent administration and are often associated with systemic side effects. In comparison to conventional drug delivery advanced drug delivery systems offer advantages such as targeted drug delivery, sustained drug release and reduction in side effects. A thorough literature search was conducted using Google Scholar, PubMed, covering publications from 2000 to 2024. The search terms included "uveitis," "pathology and pathophysiology of uveitis," "barriers in ocular drug delivery," and "uveitis conventional treatments." To refine the search results, "uveitis" was combined with different keywords such as "polymeric nanoparticles," "liposomes," "nanomicelles," "dendrimers," "nanoemulsions," "hydrogels," "implants," or "microneedles" to gather information related to each novel drug delivery system. Only English language studies were considered. The inclusion criteria encompassed both review and research articles specifically related to uveitis, with a focus on studies evaluating novel drug delivery systems for its treatment. Studies on ocular drug delivery systems unrelated to uveitis were excluded. No formal statistical analysis was conducted. This review highlights various advanced drug delivery approaches including polymeric nanoparticles, liposomes, nanomicelles, dendrimers, nanoemulsions, hydrogels, implants and microneedles for the treatment of uveitis.

Fluorinated multifunctional polymer vesicles for enhanced ocular surface penetration and synergistic treatment of dry eye disease

Current pharmacotherapy for DED is limited by a vicious inflammatory cycle in which reactive oxygen species (ROS) play a critical role. Additionally, topical eye drop therapy for DED often suffers from poor ocular availability due to multiple ocular surface barriers. Considering the key role of the ROS-NLRP3-IL-1β signaling axis in DED, in this investigation, fluorinated multifunctional polymer vesicles were developed for enhanced ocular surface penetration and synergistic DED therapy by combining ROS scavenging and immunomodulation. MCC950, an NLRP3-IL-1β inhibitor, was loaded in situ during vesicle preparation. The results demonstrated that fluorocarbon units randomly distributed in the corona layer significantly enhanced ocular surface penetration. Furthermore, the vesicle membrane, composed of polyphenylborate ester blocks, efficiently scavenged excess ROS in inflamed corneal tissue. In response to excessive ROS, a hydrophobic-to-hydrophilic conversion of the vesicle membrane facilitated the efficient release of MCC950 to modulate the NLRP3-caspase-1-IL1β pathway. We believe that this work will provide insightful guidance to achieve effective treatment of DED by enhancing ocular surface penetration.

Nanosuspension Innovations: Expanding Horizons in Drug Delivery Techniques

Nanosuspensions (NS), with their submicron particle sizes and unique physicochemical properties, provide a versatile solution for enhancing the administration of medications that are not highly soluble in water or lipids. This review highlights recent advancements, future prospects, and challenges in NS-based drug delivery, particularly for oral, ocular, transdermal, pulmonary, and parenteral routes. The conversion of oral NS into powders, pellets, granules, tablets, and capsules, and their incorporation into film dosage forms to address stability concerns is thoroughly reviewed. This article summarizes key stabilizers, polymers, surfactants, and excipients used in NS formulations, along with ongoing clinical trials and recent patents. Furthermore, a comprehensive analysis of various methods for NS preparation is provided. This article also explores various in vitro and in vivo characterization techniques, as well as scale-down technologies and bottom-up methods for NS preparation. Selected examples of commercial NS drug products are discussed. Rapid advances in the field of NS could resolve issues related to permeability-limited absorption and hepatic first-pass metabolism, offering promise for medications based on proteins and peptides. The evolution of novel stabilizers is essential to overcome the current limitations in NS formulations, enhancing their stability, bioavailability, targeting ability, and safety profile, which ultimately accelerates their clinical application and commercialization.

Global research hotspots and trends in anti-inflammatory studies in dry eye: a bibliometric analysis (2004-2024)

Background

Inflammation plays a crucial role in the pathophysiology of dry eye (DE). This study aims to provide a comprehensive overview of the current status, hotspots and trends in DE anti-inflammatory research through bibliometric analysis.

Method

All publications were searched using the Web of Science Core Collection (WoSCC) database from 2004 to 2024. Bibliometric analyses were performed using VOSviewer, R-bibliometrix, and CiteSpace, and data were managed using Microsoft Office Excel 2019.

Results

There were 603 papers published between 2004 and 2024 included in this study, with the number of papers increasing each year. The United States was the major contributor, with the largest number of publications and the greatest impact. Baylor College of Medicine was the most influential research institution. Pflugfelder, Stephen C. and Tsubota, Kazuo were the most prolific authors in this area of research, while Dana, Reza was the most cited author in the field with the highest impact. The Journal with the highest number of publications was Investigative Ophthalmology & Visual Science, while the highest impact journal was Ocular Surface. Research hotspots were focused on the mechanisms of inflammation in DE and interventions for anti-inflammatory therapy. Future studies would favor more inflammation-related targeted therapies and physical therapies.

Conclusion

This study is the first bibliometric analysis to comprehensively summarize research trends and developments in DE anti-inflammatory treatments, pointing out recent research frontiers and hot directions for scholars studying DE anti-inflammatory treatments.

Enhanced Ocular Drug Delivery of Dexamethasone Using a Chitosan-Coated Soluplus®-Based Mixed Micellar System

BACKGROUND

This study introduces a novel dexamethasone (DEX) mixed micellar system (DEX-MM) using Soluplus® and Pluronic F-127 (PF127) to enhance ocular drug delivery. The enhancement of ocular application properties was achieved by creating a chitosan-coated DEX-MM (DEX-CMM), which promotes better adherence to the ocular surface, thereby improving drug absorption.

METHODS

Using the solvent evaporation method, a formulation was developed with a Soluplus®-to-drug ratio of 1:10, enhanced with 0.25% PF127. After dispersing in water, 1% chitosan (CS) was added. The stability and integrity of DEX within the micelles were verified using attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) and differential scanning calorimetry (DSC). Additionally, in vitro and ex vivo drug release studies were conducted.

RESULTS

DEX-CMM (F6) demonstrated a particle size of 151.9 ± 1 nm and a polydispersity index (PDI) of 0.168 ± 0.003, suggesting uniformity and high electrostatic stability with a zeta potential of +35.96 ± 2.13 mV. The non-Fickian drug release mechanism indicated prolonged drug retention. Comparative analyses showed DEX-CMM outperforming a standard DEX suspension in drug release and ocular tissue permeation, with flux measurements significantly higher than the DEX suspension.

CONCLUSION

The study confirmed the efficacy of DEX-CMM in enhancing drug delivery to ocular tissues, evidenced by improved permeability. Safety evaluations using the HET-CAM test demonstrated that DEX-CMM was non-irritant, supporting its potential for effective ocular drug delivery.