Formulation and Development of Nanofiber-Based Ophthalmic Insert for the Treatment of Bacterial Conjunctivitis.

A novel ophthalmic delivery system utilizing levofloxacin-loaded, preservative-free, nanofiber-based inserts was investigated. Polyvinyl alcohol (PVA) and Poloxamer 407 (Polox)were employed as matrix materials, while hydroxypropyl-beta-cyclodextrin (HP-ß-CD) was a solubilizer. The formulations were prepared via electrospinning and characterized for fiber morphology, drug dissolution, cytotoxicity, and antimicrobial activity. Scanning electron microscopy confirmed uniform fibrous structures. Fourier Transform Infrared spectroscopy and X-ray diffraction analyses demonstrated the amorphous state of levofloxacin within the fibers. In vitro dissolution studies revealed a rapid (within 2 min) and complete drug release, with higher HP-ß-CD levels slightly delaying the release. Cytotoxicity tests showed increased HP-ß-CD concentrations induced irritation, that was mitigated by sodium hyaluronate. The antimicrobial efficacy of the nanofibers was comparable to conventional eye drops, with lower minimum inhibitory concentrations for most tested strains. The nanofibrous formulation prepared from a PVA-Polox-based viscous solution of the drug:CD 1:1 mol ratio, containing 0.4% (w/w) sodium hyaluronate) was identified as a particularly promising alternative formulation due to its rapid and complete dissolution, good biocompatibility, and effective antimicrobial properties. Its gelling properties indicate that the residence time on the eye surface can be increased, potentially reducing discomfort and enhancing therapeutic outcomes. The nanofibrous formulations enhanced antimicrobial efficacy, providing a preservative-free alternative that minimizes the potential eye irritation that might occur because of the preservative agent and reduces the administrated dose frequency by extending the drug's retention time on the eye's surface. Subsequently, it improves patients' adherence, which would reflect positively on the bioavailability. The levofloxacin-HP-ß-CD nanofibers demonstrate promise as an alternative to traditional eye drops, offering advantages in solubility, stability, and patient compliance for ocular infection treatment.

Mathematical Models of Ocular Drug Delivery.

Drug delivery is an important factor for the success of ocular drug treatment. However, several physical, biochemical, and flow-related barriers limit drug exposure of anterior and posterior ocular target tissues during drug treatment via topical, subconjunctival, intravitreal, or systemic routes. Mathematical models encompass various barriers so that their joint influence on pharmacokinetics (PKs) can be simulated in an integrated fashion. The models are useful in predicting PKs and even pharmacodynamics (PDs) of administered drugs thereby fostering development of new drug molecules and drug delivery systems. Furthermore, the models are potentially useful in interspecies translation and probing of disease effects on PKs. In this review article, we introduce current modeling methods (noncompartmental analyses, compartmental and physiologically based PK models, and finite element models) in ocular PKs and related drug delivery. The roles of top-down models and bottom-up simulations are discussed. Furthermore, we present some future challenges, such as modeling of intra-tissue distribution, prediction of drug responses, quantitative systems pharmacology, and possibilities of artificial intelligence.

Deferasirox nanosuspension loaded dissolving microneedles for ocular drug delivery.

Deferasirox (DFS) is an oral iron chelator that is employed in retinal ailments as a neuroprotectant against retinal injury and thus has utility in treating disorders such as excitoneurotoxicity and age-related macular degeneration (AMD). However, the conventional oral route of administration can present several disadvantages, e.g., the need for more frequent dosing and the first-pass effect. Microneedles (MNs) are minimally invasive systems that can be employed for intrascleral drug delivery without pain and can advantageously replace intravitreal injections therapy (IVT) as well as conventional oral routes of delivery for DFS. In this study, DFS was formulated into a nanosuspension (NS) through wet media milling employing PVA as a stabilizer, which was successfully loaded into polymeric dissolving MNs. DFS exhibited a 4-fold increase in solubility in DFS-NS compared to that of pure DFS. Moreover, the DFS-NSs exhibited excellent short-term stability and enhanced thermal stability, as confirmed through thermogravimetric analysis (TGA) studies. The mechanical characterization of the DFS-NS loaded ocular microneedles (DFS-NS-OcMNs), revealed that the system was sufficiently strong for effective scleral penetration. Optical coherence tomography (OCT) images confirmed the insertion of 81.23 ± 7.35 % of the total height of the MN arrays into full-thickness porcine sclera. Scleral deposition studies revealed 64 % drug deposition after just 5 min of insertion from DFS-NS-loaded ocular microneedles (OcMNs), which was almost 5 times greater than the deposition from pure DFS-OcMNs. Furthermore, both DFS and DFS-NS-OcMN exhibited remarkable cell viability when evaluated on human retinal pigment (ARPE) cells, suggesting their safety and appropriateness for use in the human eye. Therefore, loading DFS-NS into novel MN devices is a promising technique for effectively delivering DFS to the posterior segment of the eye in a minimally invasive manner.

Safety and tolerability of pooled human immune globulins after topical ophthalmic administration in New Zealand White rabbits.

PURPOSE: To evaluate the safety and tolerability of pooled human immune globulins, Flebogamma® 5% DIF and Flebogamma® 10% DIF, administered by topical ophthalmic instillation to New Zealand White (NZW) rabbits. METHODS: Male NZW rabbits were used in this study. In the acute single dose tolerability study, rabbits (n = 12) received a single topical dose of Flebogamma® 5% DIF. In the two-week repeated-dose tolerability study, rabbits (n = 5 for each group) were administered either Flebogamma® 5% DIF or Flebogamma® 10% DIF by topical bilateral administration four times daily (q.i.d.) between 8 am and 6 pm for a period of two weeks. Full ophthalmic examinations were conducted to evaluate ocular tolerability at baseline, Day 7, and Day 14. RESULTS: In the acute single dose study, mild hyperaemia was observed in 1 out of 4 eyes at each 4 h and 24 h post-instillation of Flebogamma® 5% DIF. In the repeated dose study, no ocular signs were detected after q.i.d. topical instillation of Flebogamma® 5% DIF, while Flebogamma® 10% DIF resulted in mild hyperaemia in 8 out of 10 eyes on Day 7, and 5 out of 10 eyes on Day 14. No positive corneal fluorescein staining was detected. Schirmer tear test results were unremarkable. No other ocular signs were observed. Administration of immune globulins had no effect on intraocular pressure. CONCLUSIONS: Flebogamma® 5% DIF and Flebogamma® 10% DIF were well-tolerated by NZW rabbits following single and repeat dose topical ophthalmic administration, supporting the future development of topical pooled human immune globulins for the treatment of ocular surface disease.

Absorption enhancement strategies in chitosan-based nanosystems and hydrogels intended for ocular delivery: Latest advances for optimization of drug permeation.

Ophthalmic diseases can be presented as acute diseases like allergies, ocular infections, etc., or chronic ones that can be manifested as a result of systemic disorders, like diabetes mellitus, thyroid, rheumatic disorders, and others. Chitosan (CS) and its derivatives have been widely investigated as nanocarriers in the delivery of drugs, genes, and many biological products. The biocompatibility and biodegradability of CS made it a good candidate for ocular delivery of many ingredients, including immunomodulating agents, antibiotics, ocular hypertension medications, etc. CS-based nanosystems have been successfully reported to modulate ocular diseases by penetrating biological ocular barriers and targeting and controlling drug release. This review provides guidance to drug delivery formulators on the most recently published strategies that can enhance drug permeation to the ocular tissues in CS-based nanosystems, thus improving therapeutic effects through enhancing drug bioavailability. This review will highlight the main ocular barriers to drug delivery observed in the nano-delivery system. In addition, the CS physicochemical properties that contribute to formulation aspects are discussed. It also categorized the permeation enhancement strategies that can be optimized in CS-based nanosystems into four aspects: CS-related physicochemical properties, formulation components, fabrication conditions, and adopting a novel delivery system like implants, inserts, etc. as described in the published literature within the last ten years. Finally, challenges encountered in CS-based nanosystems and future perspectives are mentioned.

Design and Evaluation of Ophthalmic Thermosensitive In Situ Gel of Compound Salvia.

The compound Salvia Recipe has been shown to have a relatively significant curative effect in management of cardiovascular and cerebrovascular diseases. This work aimed to prepare a thermosensitive in situ gel (ISG) delivery system that utilizes Poloxamer 407, Poloxamer 188, and hydroxypropyl methylcellulose for ocular administration of the compound Salvia recipe to treat cardiovascular and cerebrovascular diseases. The central composite design-response surface method was utilized to improve the prescription of the gel. The formulated gel was characterized and assessed in terms of stability, retention time, in vitro release, rheology, ocular irritation, pharmacokinetics studies, and tissue distribution. The gel was a liquid solution at room temperature and became semisolid at physiological temperature, prolonging its stay time in the eye. Pharmacokinetics and tissue distribution experiments indicated that thermosensitive ISG had enhanced targeting of heart and brain tissues. Additionally, it could lower drug toxicity and side effects in the lungs and kidneys. The compound Salvia ophthalmic thermosensitive ISG is a promising drug delivery system for the management of cardiovascular and cerebrovascular illnesses.

Prefilled Ophthalmic syringes - New Possibilities in Terminal Sterilization.

In a joint study carried out by Gerresheimer, Sterigenics and Früh, it could be shown that also NO2 is well suited to terminally sterilize prefilled ophthalmic syringes. In detail 5 topics were addressed: (1) Compare EtO vs. NO2 penetration into the filled syringe; (2) Analyze gas ingress though 4 different plunger stoppers including silicone oil free and standard rubber plungers; (3) Scrutinize gas ingress through 2 different cap designs based on different elastomer properties; (4) Investigate gas permeation through COP plastic barrels compared to glass; (5) Check if the Tyvek®-layer has an influence on either sterilization.Depending on the needs a suitable sterilization method, packaging and syringe type can be suggested to customers.

Comparison of Different Doses of Oral and Ocular Propranolol for Retinopathy of Prematurity: A Network Meta-Analysis.

OBJECTIVE: The efficacy and safety of propranolol for retinopathy of prematurity (ROP) remain under debate. This network meta-analysis (NMA) focuses on whether a ranking may be established for different dose levels of propranolol as treatment of ROP in terms of stage progression as the primary outcome, with appearance of plus disease and need for anti-vascular endothelial growth factors (anti-VEGFs) or laser therapy as secondary endpoints. METHODS: Fourteen studies (10 randomised controlled trials, three single-arm trials and one retrospective observational study) of 474 patients treated with oral or ocular propranolol were retrieved from databases up to April 2024. Meta-insight and model-based NMA were undertaken to evaluate the propranolol dose-response relationship. Studies were evaluated for model fit, risk of bias and Confidence of evidence In Network Meta-Analysis (CINeMA). Effect sizes were determined as odds ratio (OR) with 95% credible interval (CrI). RESULTS: Bayesian analysis showed a trend towards improved effects for propranolol given at late stages (stages 2-3; S23) of ROP progression compared with its administration at earlier stages (stages 0-1; S01). OR values for oral propranolol 1.5 and 2 mg/kg/day given at S23 were 0.13 (95% CrI 0.04-0.37) and 0.16 (95% CrI 0.04-0.61), respectively, while given at S01 were 0.28 (95% CrI 0.02-2.96) and 0.78 (95% CrI 0.14-4.43), respectively. Similarly, OR of eye propranolol 0.2% at S23 was 0.37 (95% CrI 0.09-1.00) versus an S01 OR of 0.64 (95% CrI 0.21-2.04). Surface under the cumulative ranking curve (SUCRA) analyses confirmed best probability values for oral propranolol 1.5-2 mg/kg followed by eye propranolol 0.2%, all at S23. Model-based NMA showed nonlinearity in the dose-response for oral propranolol with a trend to greater maximal effect for its administration at late versus early stages. For secondary endpoints, lower risk values were found with oral propranolol 1.5 mg/kg/day at S23 for progression to plus disease (OR 0.14; 95% CrI 0.02-0.84) and need for anti-VEGFs (OR 0.23; 95% CrI 0.05-0.93) and laser (OR 0.16; 95% CrI 0.02-1.10) therapies also followed by eye propranolol 0.2%, and a similar profile was obtained with SUCRA analysis. Lower doses (0.5-1.0 mg/kg/day) of oral propranolol retained efficacy. Threat of adverse events was estimated as risk difference versus control with no difference for eye propranolol 0.2% and oral propranolol 0.5 mg/kg/day, modest increases of risk for oral propranolol 1.0 and 1.5 mg/kg/day and the highest risk difference for oral propranolol 2.0 mg/kg/day (0.06; 95% CI -0.01 to 0.13). CONCLUSION: A diminished risk of disease progression and need for additional treatment was obtained with propranolol in ROP, but safety is a potential concern. Propranolol eye micro-drops (0.2%) can be as efficacious as oral propranolol. Nonetheless, the evidence is limited due to the paucity and quality of the available studies.

A novel liposomal formulation for ocular delivery of caspofungin: an experimental study by quality by design-based approach.

Aim: This study focuses on the development of a Caspofungin liposome for efficient ocular delivery by enhancing corneal penetration.Method: Quality by design (QbD) approach was adopted to identify critical factors that influence final liposomal formulation. The liposome developed using thin film hydration after optimization was subjected to characterization for physicochemical properties, irritation potential and corneal uptake.Results: The numerical optimization suggests an optimal formulation with a desirability value of 0.706, using CQAs as optimization goals with 95% prediction intervals. The optimized formulation showed no signs of irritation potential along with observation of significant corneal permeation.Conclusion: The liposomal formulation increased the permeability of Caspofungin, which could enhance the efficacy for the treatment of conditions, like fungal keratitis.

[Box: see text].

In situ forming hydrogels based on modified gellan gum/chitosan for ocular drug delivery of timolol maleate.

In situ forming hydrogels are suitable candidates for increasing drug residence time in ocular drug delivery. In this study, gellan gum (GG) was oxidized to form aldehyde groups and in situ gelling hydrogels were synthesized based on a Schiff-base reaction between oxidized GG (OGG) and chitosan (CS) in the presence of ß-glycerophosphate. The effect of OGG and CS concentration on the physical and chemical properties of the resulting hydrogels was investigated. The FT-IR spectroscopy confirmed the chemical modification of OGG as well as the functional groups of the prepared hydrogels. The scanning electron microscope (SEM) revealed the highly porous structure of hydrogels. The obtained hydrogels indicated a high swelling degree and degradability. Also, the rheological studies demonstrated self-healing behavior, shear thinning, thixotropy, and mucoadhesion properties for the developed hydrogels. The results of in vitro and ex vivo studies showed that the timolol-loaded hydrogel with a higher amount of OGG has a higher release rate. Moreover, the MTT cytotoxicity test on bone marrow mesenchymal stem cells (BMSCs) confirmed that developed hydrogels are not toxic. The obtained results revealed that the developed hydrogels can be a desirable choice for the ocular drug delivery of timolol in the treatment of glaucoma.

Preparation and in vivo and ex vivo studies of sirolimus nano-in-situ gel ophthalmic formulation.

Sirolimus (SR) is a macrolide with antifungal and antitumor immunosuppressant properties, classified as a selective inhibitor of mammalian target of rapamycin (mTOR). In this study, an ionic in situ gel of SR (SR-SUS-ISG) was formulated using gellan gum, exhibiting stability regardless of temperature and pH variations, causing minimal irritation. Harnessing the physiological conditions of the eye, SR-SUS-ISG underwent gelation upon contact with ions, increasing drug viscosity and prolonging retention on the ocular surface. Concurrently, SR-SUS-ISG displayed favorable shear dilution properties, reducing viscosity at ambient temperature, enhancing fluidity, and facilitating convenient packaging and transport. Biocompatibility assessments on both human corneal epithelial cells and rabbit eyes demonstrated that SR-SUS-ISG could well be tolerated. Pharmacokinetic investigations in rabbit ocular aqueous humor revealed sustained release, improved corneal penetration, and enhanced bioavailability. Additionally, in a rat corneal alkali burn model, SR-SUS-ISG exhibited inhibitory effects on corneal neovascularization, associated with decreased levels of the inflammatory factors VEGF and MMPs. These findings suggested that SR-SUS-ISG held promise as an effective ocular drug delivery system.

Dexamethasone-loaded ROS stimuli-responsive nanogels for topical ocular therapy of corneal neovascularization.

Dexamethasone (DEX) has been demonstrated to inhibit the inflammatory corneal neovascularization (CNV). However, the therapeutic efficacy of DEX is limited by the poor bioavailability of conventional eye drops and the increased risk of hormonal glaucoma and cataract associated with prolonged and frequent usage. To address these limitations, we have developed a novel DEX-loaded, reactive oxygen species (ROS)-responsive, controlled-release nanogel, termed DEX@INHANGs. This advanced nanogel system is constructed by the formation of supramolecular host-guest complexes by cyclodextrin (CD) and adamantane (ADA) as a cross-linking force. The introduction of the ROS-responsive material, thioketal (TK), ensures the controlled release of DEX in response to oxidative stress, a characteristic of CNV. Furthermore, the nanogel's prolonged retention on the corneal surface for over 8 h is achieved through covalent binding of the integrin ß1 fusion protein, which enhances its bioavailability. Cytotoxicity assays demonstrated that DEX@INHANGs was not notably toxic to human corneal epithelial cells (HCECs). Furthermore, DEX@INHANGs has been demonstrated to effectively inhibit angiogenesis in vitro. In a rabbit model with chemically burned eyes, the once-daily topical application of DEX@INHANGs was observed to effectively suppress CNV. These results collectively indicate that the nanomedicine formulation of DEX@INHANGs may offer a promising treatment option for CNV, offering significant advantages such as reduced dosing frequency and enhanced patient compliance.

Evaluation of Pregabalin bioadhesive multilayered microemulsion IOP-lowering eye drops.

In spite of available treatment options, glaucoma continues to be a leading cause of irreversible blindness in the world. Current glaucoma medications have multiple limitations including: lack of sustained action; requirement for multiple dosing per day, ocular irritation and limited options for drugs with different mechanisms of action. Previously, we demonstrated that pregabalin, a drug with high affinity and selectivity for CACNA2D1, lowered IOP in a dose-dependent manner. The current study was designed to evaluate pregabalin microemulsion eye drops and to estimate its efficacy in humans using in silico methods. Molecular docking studies of pregabalin against CACNA2D1 of mouse, rabbit, and human were performed. Pregabalin microemulsion eye drops were characterized using multiple in vivo studies and its stability was evaluated over one year at different storage conditions. Molecular docking analyses and QSPR of pregabalin confirmed its suitability as a new IOP-lowering medication that functions using a new mechanism of action by binding to CACNA2D1 in all species evaluated. Because of its prolonged corneal residence time and corneal penetration enhancement, a single topical application of pregabalin ME can provide an extended IOP reduction of more than day in different animal models. Repeated daily dosing for 2 months confirms the lack of any tachyphylactic effect, which is a common drawback among marketed IOP-lowering medications. In addition, pregabalin microemulsion demonstrated good physical stability for one year, and chemical stability for 3-6 months if stored below 25 °C. Collectively, these outcomes greatly support the use of pregabalin eye drops as once daily IOP-lowering therapy for glaucoma management.

Polystyrene Sulfonate Resin as an Ophthalmic Carrier for Enhanced Bioavailability of Ligustrazine Phosphate Controlled Release System.

Topical ocular sustained-release drug delivery systems represent an effective strategy for the treatment of ocular diseases, for which a suitable carrier has yet to be sufficiently developed. Herein, an eye-compatible sodium polystyrene sulfonate resin (SPSR) was synthesized with a uniform particle size of about 3 µm. Ligustrazine phosphate (LP) was adsorbed to SPSR by cation exchange to form LP@SPSR. LP@SPSR suspension eye drops were further developed using the combination of Carbopol 934P and xanthan gum as suspending agents. The LP@SPSR suspension showed a sustained release in vitro, which was consistent with the observed porcine corneal penetration ex vivo. Pharmacokinetics in tear fluid of rabits indicated that LP@SPSR suspension led to prolonged ocular retention of LP and a 2-fold improved the area under the drug concentration-time curve (AUC0-t). Pharmacokinetics in the aqueous humor of rabbits showed 2.8-fold enhancement in the AUC0-t compared to LP solution. The LP@SPSR suspension exhibited no cytotoxicity to human corneal epithelial cells, nor irritation was observed in rabbit eyes. Thus, the LP@SPSR suspension has been validated as a safe and sustained release system leading to enhanced ophthalmic bioavailability for treating ocular diseases.

The evolution of cyclosporine treatments for treatment of ocular surface diseases.

PURPOSE OF REVIEW: Cyclosporine is a versatile immunomodulatory drug commonly employed in modern medicine. Although cyclosporine was initially used to prevent solid organ transplant rejection, its indications have extended to treat many inflammatory or autoimmune diseases. Cyclosporin is available for use in oral, intravenous, and topical forms, including eye drops to treat corneal and ocular surface conditions. It is naturally advantageous to administer cyclosporin directly into the eye, avoiding potential and dose limiting systemic adverse effects. However, the transition from systemic to topical administration has been a challenging one. This report reviews the evolution of ophthalmic cyclosporine treatment and explores its clinical impacts and future research directions. RECENT FINDINGS: Latest advancements in formulations - from oil-based solutions to nanomicelle and gel systems and waterless formulations - have improved the therapeutic efficacy and tolerability of topically applied cyclosporine, demonstrating greater effectiveness in treating ocular surface parameters compared to oil-based solution. SUMMARY: Cyclosporine continues to be a safe and effective immunomodulatory drug in the field of ophthalmology to treat various chronic inflammatory ocular surface diseases and dry eye. Currently, there are several commercially available topical preparations available for ophthalmic use each with unique formulation and clinical outcomes.

Augmented ocular uptake and anti-inflammatory efficacy of decorated Genistein-loaded NLCs incorporated in in situ gel.

Genistein (Gen); a naturally occurring isoflavone, acts as a tyrosine kinase inhibitor and efficiently downregulates inflammatory cytokines, which are pivotal in eye inflammation. Also, Gen suffers from sparse ocular bioavailability due to poor solubility. In this work, nanostructured lipid carriers (NLCs) were successfully fabricated by using solid (stearic acid and compritol) and liquid (oleic acid) lipids. The optimized Gen-loaded NLCs showed a nanosize range of 140-246 nm, ≥ 98 % entrapment efficiency, and controlled release over 48 h. The ζ-potential of NLCs was increased from -27.3 mV to 25-27.4 mV due to surface modification with chitosan (CS) or eudragit RS100 (ERS 100). All NLCs showed prominent biocompatibility with enhanced cellular uptake on corneal stromal fibroblasts. Moreover, the different NLCs were incorporated into a mucoadhesive in situ gel. The optimized in situ gel (G9), containing 20 % poloxamers and 0.5 % hydroxyethyl cellulose, exhibited excellent gelling ability within 10.5 s, gelling temperature at 33.1 ± 0.6 ℃, spreadability diameter of 4.73 ± 0.12 cm, shear-thinning behavior, and 20 min ex vivo mucoadhesion time with drug release for 120 h. The in vivo results showed distinguished permeation and distribution potential for ocular delivery. In vivo anti-inflammatory effects after 3 days of treatment with CS-Gen-NLCs/G9 and ERS-Gen-NLCs/G9 revealed a downregulation of interleukin-6 levels in the cornea and retina compared to the untreated group. Our research highlights the promising anti-inflammatory potential of ERS-Gen-NLCs/G9 as an efficient, non-irritant Gen nanodelivery system for managing anterior and posterior ocular inflammation.

Advances in the development of lipid nanoparticles for ophthalmic therapeutics.

Previously, researchers have employed Lipid nanoparticles (LNPs) to directly encapsulate medicines. In the realm of gene therapy, researchers have begun to employ lipid nanoparticles to encapsulate nucleic acids such as messenger RNA, small interfering RNA, and plasmid DNA, which are known as nucleic acid lipid nanoparticles. Recent breakthroughs in LNP-based medicine have provided significant prospects for the treatment of ocular disorders, such as corneal, choroidal, and retinal diseases. The use of LNP as a delivery mechanism for medicines and therapeutic genes can increase their effectiveness while avoiding undesired immune reactions. However, LNP-based medicines may pose ocular concerns. In this review, we discuss the general framework of LNP. Additionally, we review adjustable approaches and evaluate their possible risks. In addition, we examine newly described ocular illnesses in which LNP was utilized as a delivery mechanism. Finally, we provide perspectives for solving these potential issues.

Block copolymer micelles as ocular drug delivery systems.

Block copolymer micelles, formed by the self-assembly of amphiphilic polymers, address formulation challenges, such as poor drug solubility and permeability. These micelles offer advantages including a smaller size, easier preparation, sterilization, and superior solubilization, compared with other nanocarriers. Preclinical studies have shown promising results, advancing them toward clinical trials. Their mucoadhesive properties enhance and prolong contact with the ocular surface, and their small size allows deeper penetration through tissues, such as the cornea. Additionally, copolymeric micelles improve the solubility and stability of hydrophobic drugs, sustain drug release, and allow for surface modifications to enhance biocompatibility. Despite these benefits, long-term stability remains a challenge. In this review, we highlight the preclinical performance, structural frameworks, preparation techniques, physicochemical properties, current developments, and prospects of block copolymer micelles as ocular drug delivery systems.

Amlodipine Ocular Delivery Restores Ferning Patterns and Reduces Intensity of Glycosylated Peak of Carrageenan-Induced Tear Fluid: An In-Silico Flexible Docking with IL-ß1.

BACKGROUND: The tear ferning test can be an easy clinical procedure for the evaluation and characterization of the ocular tear film. OBJECTIVE: The objective of this study was to examine the restoration of tear ferning patterns and reduction of glycosylation peak after amlodipine application in carrageenan-induced conjunctivitis. METHODS: At the rabbit's upper palpebral region, carrageenan was injected for cytokine-mediated conjunctivitis. Ferning pattern and glycosylation of the tear fluid were characterized using various instrumental analyses. The effect of amlodipine was also examined after ocular instillation and flexible docking studies. RESULTS: Optical microscopy showed a disrupted ferning of the tear collected from the inflamed eye. FTIR of the induced tear fluid exhibited peaks within 1000-1200 cm-1, which might be due to the protein glycosylation absent in the normal tear spectrogram. The glycosylation peak reduced significantly in the tear sample collected from the amlodipine-treated group. Corresponding energy dispersive analysis showed the presence of sulphur, indicating protein leakage from the lacrimal gland in the induced group. The disappearance of sulphur from the treated group indicated its remedial effect. The flexible docking studies revealed a stronger binding mode of amlodipine with Interleukin-1ß (IL-1ß). The reduction in the intensity of the glycosylated peak and the restoration offering are probably due to suppression of IL-1ß. CONCLUSION: This study may be helpful in obtaining primary information for drug discovery to be effective against IL-1ß and proving tear fluid as a novel diagnostic biomarker.