Shahla Mirzaeei

Glaucoma is a collection of disorders that result in permanent vision loss and is characterized by a gradual decline in retinal ganglion cells. While it may not always be high, intraocular pressure (IOP) is the sole risk factor that can be modified according to extensive clinical research. Glaucoma remains the leading cause of irreversible blindness, yet early treatment lowering intraocular pressure is effective in slowing the rate of visual deterioration. Issues like poor absorption, low bioavailability, and short drug resistance time have thus made the management of glaucoma challenging when using conventional ophthalmic drugs. Thus, extensive research has been conducted to explore specific nanodrug delivery systems from various nanocarriers such as nanoparticles, micelles, liposomes and nanofibers, with a focus on systems that have achieved drug release for more than 12 h. These carriers have demonstrated substantial improvements in a lot of the evaluated aspects: enhancing ocular barrier-crossing capabilities, improving bioavailability, prolonging drug release, targeting active tissues of interest, and reducing IOP. This review covers recent developments in nanocarrier ocular delivery systems regarding the management of glaucoma. In this study, the advantages and disadvantages of each system were evaluated and their potential for advancing translation from research to clinic were assessed.

Purpose: This study aimed to determine the efficacy of ceftazidime-containing nanofibers in treating corneal ulcers induced by the bacterium Pseudomonas aeruginosa in an animal model. Methods: This animal-assisted intervention involved 12 adult male New Zealand rabbits, each weighing between 3.5 and 4 kg. The animals were randomly assigned to two groups of six: an intervention group that received a ceftazidime nanofiber insert treatment and a control group that received no treatment. In the intervention group, the right eye was used as a test sample for ulcer induction and ceftazidime-loaded nanofiber examination, while the left eye served as a control to observe any inflammatory or irritating symptoms caused by the nanofiber in the absence of the active pharmaceutical compound. Examinations were performed daily, with slit lamp images taken on days 2, 4, 6, 9, 12, and 15. Clinical responses were recorded and graded according to a clinical examination table. Results: Prior to the intervention, both groups exhibited a similar severity of corneal ulcers. After 48 hours, four of the six rabbits in the intervention group were positive for Pseudomonas aeruginosa in their cultures, and the remaining two tested negative. Meanwhile, in the control group, three rabbits had positive cultures and three had negative cultures. After 96 hours from the onset of the treatment and the application of the ceftazidime nanofiber insert, three rabbits that initially presented with positive cultures exhibited negative cultures in the subsequent examinations; however, one rabbit still had positive smear and culture results. On day 9, the intervention group showed complete disappearance of infiltration and epithelial damage. However, the rabbit eyes in the control group demonstrated increased signs of involvement on days 6 and 9 compared to the previous examinations. Furthermore, the clinical results indicated a significant difference in the mean corneal ulcer scores between the two groups (P < 0.001). Conclusion: Given the observed effectiveness of the developed nanofiber in treating corneal ulcers induced by P. aeruginosa, this nanodrug delivery system has the potential to serve as a viable option for ocular drug delivery.

The eye is one of the most important and sensitive organs of the human body that is naturally protected by the membrane and vascular barriers. Although these barriers protect the eye effectively, different types of diseases such as age-related macular degeneration (AMD), diabetic macular edema (DME), cataract, proliferative vitreoretinopathy (PVR), uveitis, cytomegalovirus (CMV), and glaucoma and other physiological factors affect the posterior and anterior portions of the eye. Effective ocular drug delivery is still a major and serious challenge in the medical field. Conventional methods are not efficient due to many limitations including low ocular bioavailability of drugs, low levels of drugs in the ocular tissue and washed-off drugs from the eye in a very short period of time. The use of nanotechnology to design drug delivery systems to achieve controlled release as well as penetration of protective barriers has been promising. In the past decades, different types of nano-scaled ocular drug delivery systems have been developed. Some of these nano-systems are effective for drug delivery to the anterior and some of them to the posterior segment. In this article, the authors reviewed and discussed the efficiency and effectiveness of different types of nanoscale ocular drug deliveries with their advances and challenges.

Background/objectives: The aim of the study was to create a nanofiber insert incorporating Timolol (TIM) and Dorzolamide (DOR), targeting the management of glaucoma. This condition encompasses a variety of chronic, advancing ocular disorders typically associated with elevated intraocular pressure (IOP). Methods: The insert was made of Eudragite RL100 (EUD) polymer, a biocompatible material with high bioavailability, using the electrospinning method. The inserts were studied for morphology, drug–polymer interaction, physicochemical properties, and in vitro drug-release study. The pharmacokinetic properties of fibers were examined alongside consideration for irritation using a rabbit model and cell compatibility. Results: The results of the in vitro drug-release test showed retention and controlled release of both DOR/TIM over 80 h. Morphological examination demonstrated uniform nanofibers with mean diameters < 465 nm. The cell compatibility test showed a high percentage of cell survival, and none of the formulations irritated the rabbit’s eye. The Area Under the Curve (AUC0-72) for DOR and TIM in EDT formulations was approximately 3216.63 ± 63.25 µg·h/mL and 2598.89 ± 46.65 µg·h/mL, respectively, with Mean Residence Times (MRTs) of approximately 21.6 ± 0.19 h and 16.29 ± 6.44 h. Conclusions: Based on the results, the dual drug-loaded nanofiber preservative-free system can potentially be a suitable alternative to eye drops and can be used to reduce fluctuation and dose frequency.

Aim: The present study aimed to prepare and evaluate fexofenadine self-microemulsifying drug-delivery systems (SMEDDS) formulation and to determine and compare its intestinal permeability using in situ single-pass intestinal perfusion (SPIP) technique. Methods: Fexofenadine-loaded SMEDDS were prepared and optimized. Droplet size, polydispersity index, zeta potential, drug release and intestinal permeability were evaluated. Results: Optimized formulation consisted of 15% oil, 80% surfactant and 5% cosolvent. Droplet size and drug loading of optimized formulation was 13.77 nm and 60 mg/g and it has released 90% of its drug content. Intestinal permeability of fexofenadine was threefold enhanced in SMEDDS compared with free fexofenadine. Conclusion: The results of our study revealed that SMEDDS could be a promising tool for oral delivery of fexofenadine with enhanced dissolution rate and intestinal permeability.