Shiva Taghe

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.

Conventional anti-infective eye drops are the most common forms of drugs prescribed for the management of topical ocular infections. Despite their convenience, topical eye drops face multiple challenges, including limited bioavailability and repetitive administration. The present study aimed to prepare, evaluate, and compare film-structured and nanofibrous ocular inserts using biocompatible polymers of polyvinyl alcohol (PVA) and polycaprolactone (PCL) to achieve sustained ciprofloxacin Hydrochloride (CIP) delivery. The nanofibrous formulations were prepared by electrospinning and glutaraldehyde crosslinking while the film formulation was prepared by solvent casting. Nanofibrous inserts had mean diameters in the range 330–450 nm. Both film and nanofibrous inserts were strong, although the nanofibers had higher flexibility. In vitro antibacterial efficacy against Staphylococcus aureus and Escherichia coli was observed for all formulations and cell viability of more than 70% confirmed their non-toxicity. In vitro release studies showed prolonged release of 2 days for the film and 5 days for the nanofibers compared with a 10-h release of CIP from the eye drop. Pharmacokinetic studies of rabbits’ eyes showed 4.5–5-folds higher AUC for the nanofiber formulations compared with the eye drop. Thus, prolonged-release film-structured and nanofibrous inserts are suitable carriers for ocular delivery of CIP.

The fast elimination of drugs from the cornea is one of many challenges associated with the topical administration of conventional dosage forms. The present manuscript aimed to prepare modified-release inserts containing erythromycin (ERY) to enhance drug delivery and address the aforementioned limitation. Film formulations were developed using Eudragit^® L100 (EUD) and Polyvinyl Alcohol (PVA) polymers. ERY-loaded EUD-based nanoparticles were developed by the colloidal dispersion method using PVA as the emulsifier. The film-casting method was applied to form the mucoadhesive films using sodium alginate, gelatin, cyclodextrin-α, and β as polymeric film matrices. Different physicochemical properties of the optimized formulations and in vitro release profiles were evaluated. The in vivo evaluation was performed by collecting tear samples of rabbits using a novel, non-invasive method following the administration of inserts in the cul-de-sac. The ERY amount was assayed using a microbiological assay. The developed films showed prolonged in vitro and in vivo release profiles over five to six days; they had suitable physicochemical properties and a tensile strength of 2–3 MPa. All formulations exhibited antibacterial efficacy against E. coli and S. aureus with more than 20 mm diameter of inhibited growth zones. None of the formulations caused irritation to the rabbit’s eye. The inserts showed promising pharmacokinetics with AUC_0–120 of 30,000–36,000 µg·h/mL, a C_max of more than 1800 µg/mL at 4 h, and maintained drug concentration over the threshold of 5 µg/mL during the following 120 h of study. Nanoparticle-containing, mucoadhesive films could be fabricated as ocular inserts and can prolong the topical ocular delivery of ERY.

Purpose: Conventional topical dosage forms face with some challenges like low intraocular bioavailability, which could be overcome by application of novel drug delivery systems. Therefore, this study was conducted to prepare azithromycin (AZM)-loaded chitosan/polyvinyl alcohol/polyvinyl pyrrolidone (CS/PVA-PVP) nanofibers with the prolonged antibacterial activity by electrospinning method. Methods: After preparation of nanofibers, they were characterized in terms of physicochemical and morphological properties. In-vitro and in –vivo release of the drug from nanofibers were evaluated using microbial assay against the Micrococcus luteus. Antibacterial efficacy of the nanofibers was assessed. The ophthalmic irritation test was also performed. MTT test was carried out to evaluate cytotoxicity of the formulations. Results: All the formulations were found to be stable with uniform thickness, weight, and drug content. Nanofibers had a diameter range from 119±29 to 171±39 nm. The inserts were non-irritant and non-toxic to the rabbits҆ eye. Based on the obtained results, the crosslinked AZM nanofibers showed slower and more controlled drug release in tear fluid compared to the non-crosslinked ones, within 184 h. Conclusion: Our results revealed that the prepared nanofibers could be considered as suitable and non-invasive inserts for the prolonged ophthalmic delivery of azithromycin.

Polymeric inserts containing azithromycin-loaded Eudragit^® L100 nanoparticles were developed to sustain the drug release and enhance its ocular performance. The solvent diffusion technique was employed to prepare nanoparticles. The developed nanoparticles (NPs) were fully characterized and investigated. The solvent casting method was used to prepare azithromycin ocular inserts (azithromycin, AZM film) by adding hydroxypropyl methylcellulose (HPMC) or hydroxyethyl cellulose (HEC) solutions after the incorporation of AZM-loaded Eudragit^® L100 nanoparticles into plasticized PVA (polyvinyl alcohol) solutions. The optimized nanoparticles had a particle size of 78.06 ± 2.3 nm, zeta potential around −2.45 ± 0.69 mV, polydispersity index around 0.179 ± 0.007, and entrapment efficiency 62.167 ± 0.07%. The prepared inserts exhibited an antibacterial effect on Staphylococcus aureus and Escherichia coli cultures. The inserts containing AZM-loaded nanoparticles showed a burst release during the initial hours, followed by a sustained drug release pattern. Higher cumulative corneal permeations from AZM films were observed for the optimized formulation compared to the drug solution in the ex-vivo trans-corneal study. In comparison to the AZM solution, the inserts significantly prolonged the release of AZM in rabbit eyes (121 h). The mucoadhesive inserts containing azithromycin-loaded Eudragit^® L100 nanoparticles offer a promising approach for the ocular delivery of azithromycin (antibacterial and anti-inflammatory) to treat ocular infections that require a prolonged drug delivery.