Topical ocular delivery of NSAIDs

Recent updates on ocular disease management with ophthalmic ointments

Ophthalmic diseases can result in permanent vision loss and blindness. Convenient topical and systemic treatments are preferred to address these sight-threatening conditions. However, the unique anatomy of the eye presents challenges for drug delivery. Various ophthalmic ointment formulations have been developed to enhance bioavailability in the eye to prolong residence time and improve corneal permeability. This article explores a wide range of ocular diseases affecting individuals globally and how ointments are used to manage them. From eye to ocular barriers, this review focuses on published scientific research and formulation strategies for severe ocular complications using conventional topical ointments. Additionally, it delves through patented technologies and marketed formulations supporting the use of ointments in ocular drug delivery.

Acetazolamide encapsulation in elastin like recombinamers using a supercritical antisolvent (SAS) process for glaucoma treatment

Glaucoma, the second most common cause of blindness worldwide, requires the development of new and effective treatments. This study introduces a novel controlled-release system utilizing elastin-like recombinamers (ELR) and the Supercritical Antisolvent (SAS) technique with supercritical CO2. Acetazolamide (AZM), a class IV drug with limited solubility and permeability, is successfully encapsulated in an amphiphilic ELR at three different ELR:AZM ratios, yielding up to 62 %. Scanning electron microscopy (SEM) reveals spherical microparticles that disintegrate into monodisperse nanoparticles measuring approximately 42 nm under physiological conditions. The nanoparticles, as observed via Transmission Electron Microscopy (TEM) and Atomic Force Microscopy (AFM), do not exhibit aggregates, a fact confirmed by the zeta potential displaying a value of -33 mV over a period of 30 days. Transcorneal permeation tests demonstrate a 10 % higher permeation level compared to the control solution, which increases to 30 % after 2 h. Ocular irritation tests demonstrate no adverse effects or damage. Intraocular pressure (IOP) tests conducted on hypertensive rabbits indicate greater effectiveness for all three analyzed formulations, suggesting enhanced drug bioavailability during treatment. Consequently, the combination of recombinant biopolymers and high-pressure techniques represents a promising approach for advancing glaucoma therapy, emphasizing its potential clinical significance.

Effect of topical bromfenac on intraretinal cystoid lesion in simultaneous cataract and idiopathic epiretinal membrane surgery

PURPOSE

To investigate the effect of topical nonsteroidal anti-inflammatory drugs (NSAIDs,) bromfenac on the intraretinal cystic lesions (IRC) when performing simultaneous cataract and idiopathic epiretinal membrane (iERM) surgery.

METHODS

This study included patients with iERM who had been followed up for 6 months after vitrectomy, membrane removal, and concurrent cataract surgery. Eyes were treated with topical bromfenac or not. The baseline fluorescein angiography (FA) was obtained to assess the microvascular leakage (ML). Structural changes of macula, including IRC and central macular thickness (CMT) were assessed using optical coherence tomography (OCT). The main outcome measures were changes in IRCs and best-corrected visual acuity (BCVA) regarding FA findings.

RESULTS

One hundred eighteen eyes were included. IRC and ML were observed in 51 eyes (43.2%) and 63 eyes (53.4%), respectively. The IRC did not show any association with the ML. Of total, 29 eyes (24.6%) were treated with topical bromfenac (Group A). Compared to Group B, topical bromfenac did not show beneficial effects in aspect of preventions for the newly developed IRC and treatment for pre-existed IRC. Whether the ML existed or not, topical bromfenac did not show any different effect on the changes in BCVA and IRC.

CONCLUSION

When performing simultaneous cataract and ERM surgery, topical NSAIDs, bromfenac did not show beneficial effects on the preventions and treatment of IRC in both eyes with and without the ML.

Nanomicellar eye drops: a review of recent advances

INTRODUCTION

Research on nanotechnology in medicine has also involved the ocular field and nanomicelles are among the applications developed. This approach is used to increase both the water solubility of hydrophobic drugs and their penetration/permeation within/through the ocular tissues since nanomicelles are able to encapsulate insoluble drug into their core and their small size allows them to penetrate and/or diffuse through the aqueous pores of ocular tissues.

AREAS COVERED

The present review reports the most significant and recent literature on the use of nanomicelles, made up of both surfactants and amphiphilic polymers, to overcome limitations imposed by the physiology of the eye in achieving a high bioavailability of drugs intended for the therapeutic areas of greatest commercial interest: dry eye, inflammation, and glaucoma.

EXPERT OPINION

The results of the numerous studies in this field are encouraging and demonstrate that nanomicelles may be the answer to some of the challenges of ocular therapy. In the future, new molecules self-assembling into micelles will be able to meet the regulatory requirements for marketing authorization for their use in ophthalmic formulations.

Niosome as a promising tool for increasing the effectiveness of anti-inflammatory compounds

Niosomes are drug delivery systems with widespread applications in pharmaceutical research and the cosmetic industry. Niosomes are vesicles of one or more bilayers made of non-ionic surfactants, cholesterol, and charge inducers. Because of their bilayer characteristics, similar to liposomes, niosomes can be loaded with lipophilic and hydrophilic cargos. Therefore, they are more stable and cheaper in preparation than liposomes. They can be classified into four categories according to their sizes and structures, namely small unilamellar vesicles (SUVs), large unilamellar vesicles (LUVs,), multilamellar vesicles (MLVs), and multivesicular vesicles (MVVs). There are many methods for niosome preparation, such as thin-film hydration, solvent injection, and heating method. The current study focuses on the preparation methods and pharmacological effects of niosomes loaded with natural and chemical anti-inflammatory compounds in kinds of literature during the past decade. We found that most research was carried out to load anti-inflammatory agents like non-steroidal anti-inflammatory drugs (NSAIDs) into niosome vesicles. The studies revealed that niosomes could improve anti-inflammatory agents' physicochemical properties, including solubility, cellular uptake, stability, encapsulation, drug release and liberation, efficiency, and oral bioavailability or topical absorption. See also the graphical abstract(Fig. 1).

Controlled release, chitosan-tethered luteolin phytocubosomes; Formulation optimization to in-vivo antiglaucoma and anti-inflammatory ocular evaluation

A chitosan-coated luteolin-loaded phytocubosomal system was prepared to improve the pharmacodynamic performance of luteolin in the treatment of glaucoma and ocular inflammation after topical ocular administration. Luteolin, a potent anti-oxidant herbal drug with poor aqueous solubility, was complexed with phospholipid. The prepared phytocubosomes were coated with chitosan, producing homogenously distributed nanosized particles (258 ± 9.05 nm) with a positive charge (+49 ± 6.09 mV), improved EE% (96 %), and increased concentration of encapsulated drug to 288 μg/ml. Polarized light microscopy revealed a cubic phase. Chitosan-coated phytocubosomes showed a sustained drug release profile (38 % over 24 h) and improved anti-oxidant activity (IC50 of 32 μg/ml). Ex vivo transcorneal permeation was higher by 3.60 folds compared to luteolin suspension. Irritancy tests confirmed their safety in ocular tissues after single and multiple administrations. The pharmacodynamic studies on glaucomatous rabbit eyes demonstrated 6.46-, 3.88-, and 1.89-fold reductions in IOP of chitosan-coated phytocubosomes compared to luteolin suspension, cubosomes, and phytocubosomes, respectively. Pharmacodynamic anti-inflammatory studies revealed faster recovery capabilities of chitosan-coated phytocubosomes over other formulations. Thus, chitosan-coated phytocubosomes could be a promising ocular hybrid system for delivering herbal lipophilic drugs such as luteolin.

Preparation of polycaprolactone and polymethacrylate nanofibers for controlled ocular delivery of ketorolac tromethamine: Pharmacokinetic study in Rabbit's Eye

Ophthalmitis is an inflammation of the eye triggered by various conditions including diseases, allergy, trauma, or surgery. Management of this condition usually includes administration of topical anti-inflammatory eye drops such as nonsteroidal anti-inflammatory drugs. To overcome the challenges of conventional eye drops such as frequent administration and low intraocular bioavailability, nanofibrous inserts of Ketorolac tromethamine (KET) were developed in this study. Polycaprolactone and polymethacrylate containing KET were electrospun to prepare biocompatible and biodegradable nanofibers. The inserts were studied for morphology, drug-polymer interaction, physicochemical properties, cell viability, in vitro drug release study and pharmacokinetic study in rabbit's eye. Uniform nanofibers with mean diameters < 350 nm were developed. Suitable mechanical properties with tensile strength up to 2.8 MPa indicated high strength and flexibility of inserts. Nanofibers exhibited controlled drug release for up to 140 h at a concentration more than 50 μg/ml in tears without causing any damage or irritation to the eye. Formulations indicated enhanced pharmacokinetics with 6- to 8-times higher Area Under the Curve (AUC0-144) compared to KET eye drop. Acceptable cell viability confirmed the safety of inserts. Due to the fact that this preservative-free polymer insert can obtain therapeutic concentration in the tear film without fluctuation, it can be a suitable alternative for the treatment of intraocular inflammations with less complications, easier use, and even higher intraocular penetration.

Macular Edema Following Silicone Oil Tamponade for Retinal Detachment: A Literature Review

Macular edema (ME) is a major cause of reduced vision following intraocular surgery. Although the pathophysiology of ME is not completely understood, inflammatory mediators play a key role. The incidence of ME following pars plana vitrectomy with silicone oil tamponade varies between 13% and 27%. ME usually resolves spontaneously following silicone oil removal, but treatment may be required for resistant cases. In this review, the mechanisms of ME formation after pars plana vitrectomy, its incidence, and its possible therapeutic approaches are discussed.

Real-world treatment patterns and economic burden of post-cataract macular edema

BACKGROUND

Post-cataract macular edema (PCME) is a condition that can occur in patients following cataract surgery without risk factors and complications. Although 80% of patients experience spontaneous resolution after 3 to 12 months, in persistent cases, it can lead to permanent vision loss if left untreated. There are currently no standardized treatment guidelines for PCME, and there have been limited studies showing the impact of PCME on annual Medicare spending and ophthalmology-related outpatient visits per case compared to those without the complication. This study aims to evaluate real-world treatment patterns and the economic burden of patients with PCME.

METHODS

This retrospective claims analysis identified patients from the IBM® MarketScan® Commercial and Medicare Supplemental databases. Patients with (n = 2430) and without (n = 7290) PCME 1 year post cataract surgery were propensity score matched 1:3 based on age, geographic region, diabetes presence, cataract surgery type, and Charlson Comorbidity Index. Treatment pattern analysis for each PCME patient summarized the distribution of medications across lines of therapy. Economic burden analysis compared the mean number and costs of eye-related outpatient visits, optical coherence tomography imaging scans, and ophthalmic medications between the 2 groups using linear regression models.

RESULTS

Treatment pattern analysis found 27 different treatment combinations across 6 treatment lines. The most common first-line treatments were topical steroid drops (372 [30%]), topical nonsteroidal anti-inflammatory drug drops (321 [27%]), and intraocular or periocular injectable steroids (189 [15%]). Compared to match controls, PCME patients averaged 6 additional eye-related outpatient office visits (95% CI: 5.7-6.2) resulting in an additional $3,897 (95% CI: $3,475 - $4,319) in total costs. Patients filled 3 more ophthalmology-related outpatient prescription medications (95% CI: 2.8-3.2), adding $371 in total cost (95% CI: $332 - $410).

CONCLUSIONS

PCME treatment patterns showed wide clinical variability in treatments and time, specifically regarding injectable treatments and combination therapy. Additionally, significantly higher healthcare resource use and economic burden were found for both patients and payers when comparing PCME patients to non-PMCE controls. These results highlight the need for treatment standardization and demonstrate that interventions targeted at preventing PCME may be valuable.

Formulation and In-Vitro/Ex-Vivo Characterization of Pregelled Hybrid Alginate-Chitosan Microparticles for Ocular Delivery of Ketorolac Tromethamine

Innovative hybrid chitosan-sodium alginate (Ch-Ag) microparticles (MPs) were fabricated using both the ionic gelation method as well as the pre-gelation technique. The hybrid Ch-Ag MPs were studied for size, zeta potential, morphology, mucoadhesion, in-vitro release, corneal permeation, and ocular irritation using lens and corneal epithelial cell lines. The average particle size ranged from 1322 nm to 396 nm. The zeta potential for the prepared formulations showed an increase with increasing Ch concentrations up to a value of >35 mV; the polydispersity index (PDI) of some optimized MPs was around 0.1. Compared to drug-free MPs, ketorolac-loaded Ch-Ag MPs demonstrated a drug proportion-dependent increase in their size. SEM, as well as TEM of KT-loaded MPs, confirmed that the formed particles were quasi-spherical to elliptical in shape. The KT release from the MPs demonstrated a prolonged release profile in comparison to the control KT solution. Further, mucoadhesion studies with porcine mucin revealed that the KT-loaded MPs had effective mucoadhesive properties, and polymeric particles were stable in the presence of mucin. Corneal permeation was studied on bovine eyes, and the results revealed that Ch-based MPs were capable of showing more sustained KT release across the cornea compared with that for the control drug solution. Conclusively, the cytotoxicity assay confirmed that the investigated MPs were non-irritant and could confer protection from direct drug irritation of KT on the ocular surface. The MTT cytotoxicity assay confirmed that KT-loaded MPs showed acceptable and reasonable tolerability with both human lens and corneal epithelial cell lines compared to the control samples.

Topical bromfenac as adjunctive treatment with intravitreal ranibizumab for diabetic macular edema

PURPOSE

To determine the safety and efficacy of adding topical bromfenac 0.09% in the treatment of diabetic macular edema.

METHODS

Seventy patients (70 eyes) with center involved diabetic macular edema with macular thickness (300-500 μm) were included. Patients were divided randomly into two groups: 35 eyes in each group. Both groups were treated with intravitreal ranibizumab monthly for three consecutive months. Bromfenac 0.09% eye drops twice daily was added to the treatment of study group for six months from commencement of treatment. The efficacy of topical bromfenac was evaluated by comparing both groups through follow-up period as regards to visual acuity, central and average thickness and the need for re-injection.

RESULTS

Patients treated with topical bromfenac in addition to intravitreal ranibizumab revealed significant improvement in visual acuity, more reduction in central and average macular thickness and less tendency to need reinjection compared to those treated with ranibizumab alone (p 0.013, p 0.010 and p 0.022, respectively). No side effects was encountered with the use of topical bromfenac.

CONCLUSION

Topical bromfenac 0.09% twice a day could enhance and sustain the efficacy of intravitreal ranibizumab in the treatment of diabetic macular edema without increasing the incidence of corneal side effects.

Thermoresponsive in-situ gel containing hyaluronic acid and indomethacin for the treatment of corneal chemical burn

Ocular chemical burns are prevalent injuries that must have immediate and effective treatment to avoid complications. Aiming to improve bioavailability and efficacy, a poloxamer-based thermoresponsive in-situ gelling system containing hyaluronic acid and indomethacin was developed. Formulations with different polymeric proportions were screened through rheological measurements resulting in an optimized system (F2) with gelling temperature of 34.2 ± 0.11 °C. Its maximum viscosity varied from 77.33 mPa (25 °C) to 82.95 mPa (34 °C) following a non-Newtonian profile and a pH of 6.86 ± 0.01. No incompatibilities were found after infrared analysis. Polarized light microscopy and cryo-transmission electron microscopy have demonstrated micelles of nano-sized dimensions (21.86 nm) with indomethacin entrapped in the core, forming a polymeric network under heating. In vitro tests revealed a cumulative release of 59.75 ± 3.17 % up to 24 h under a sustained release profile. Results from HET-CAM assay indicated that F2 was well tolerated. Corneal wound healing was significantly faster in animals treated with F2 compared to a commercial formulation and an untreated group. These findings suggests that F2 could be an efficient system to delivery drugs into the ocular surface improving wound healing.

Secretome of human umbilical cord mesenchymal stem cell maintains skin homeostasis by regulating multiple skin physiological function

Skin is the largest organ in the body and the first defense to resist various diseases and external stimuli that easily cause infection and inflammation. Aseptic inflammation, barrier damage, and foreign aid pressure induce the destruction and damage to the skin microenvironment. Subsequently, it destroys the skin's physiological function, leading to the maintenance and circulation of steady-state imbalance and aggravating the process of skin disorders. Our study evaluated the therapeutic potential of the secretome of human umbilical cord mesenchymal stem cells (UC-CM) for dermatological diseases in adult human skin cells, ex vivo skin tissue, and a 3D skin model. Our data suggested several advantages of UC-CM due to (1) their low cytotoxicity and sensitization properties; (2) their anti-inflammatory capacity for treating inflammatory chronic cutaneous diseases; (3) their enhanced capacity of the skin barrier for treating abnormal barrier metabolism; and (4) their positive impact on restoring skin homeostasis due to effective regulation ability of skin physiological function including cell apoptosis, detoxification, and anti-aging. We thus envisage that the possibility of harnessing the therapeutic potential of UC-CM might benefit patients suffering from inflammatory skin disorders such as atopic dermatitis, acne, and psoriasis.

Topical Anti-Inflammatory Agents for Non-Infectious Uveitis: Current Treatment and Perspectives

Non-infectious uveitis represents a heterogenous group of immune-mediated ocular diseases, which can be associated with underlying systemic disease. While the initial choice of treatment of non-infectious uveitis depends on a number of factors such as anatomical location and degree of inflammation, topical therapies often remain the initial choice of non-invasive therapy. In this narrative review, we aim to describe the literature on non-infectious uveitis, with specific focus on the current perspective on topical anti-inflammatory therapy.

Melatonin loaded hybrid nanomedicine: DoE approach, optimization and in vitro study on diabetic retinopathy model

Melatonin (MEL) is a pleiotropic neurohormone of increasing interest as a neuroprotective agent in ocular diseases. Improving the mucoadhesiveness is a proposed strategy to increase the bioavailability of topical formulations. Herein, the design and optimization of MEL-loaded lipid-polymer hybrid nanoparticles (mel-LPHNs) using Design of Experiment (DoE) was performed. LPHNs consisted of PLGA-PEG polymer nanoparticles coated with a cationic lipid-shell. The optimized nanomedicine showed suitable size for ophthalmic administration (189.4 nm; PDI 0.260) with a positive surface charge (+39.8 mV), high encapsulation efficiency (79.8 %), suitable pH and osmolarity values, good mucoadhesive properties and a controlled release profile. Differential Scanning Calorimetry and Fourier-Transform Infrared Spectroscopy confirmed the encapsulation of melatonin in the systems and the interaction between lipids and polymer matrix. Biological evaluation in an in vitro model of diabetic retinopathy demonstrated enhanced neuroprotective and antioxidant activities of mel-LPHNs, compared to melatonin aqueous solution at the same concentration (0.1 and 1 μM). A modified Draize test was performed to assess the ocular tolerability of the formulation showing no signs of irritation. To the best our knowledge, this study reported for the first time the development of mel-LPHNs, a novel and safe hybrid platform suitable for the topical management of retinal diseases.

Chitosan/sulfobutylether-β-cyclodextrin based nanoparticles coated with thiolated hyaluronic acid for indomethacin ophthalmic delivery

Indomethacin (IND) is topically administered for the treatment of the anterior segment diseases such as conjunctivitis, uveitis, and inflammation prevention for post-cataract surgery, as well as posterior segment diseases as macular edema. Currently IND is available as 0.1% w/v hydroxypropyl-β-cyclodextrin-based eye drop formulation and its bioavailability is limited by several drawbacks such as the nasolacrimal duct draining, the reflex blinking and the low volume of the conjunctival sac. In this study, chitosan (CS)/sulfobutylether-β-cyclodextrin (SBE-β-CD) based nanoparticles (NPs) with a mean diameter of 340 (±7) nm, a ζ-potential value of +18.3 (±0.5) mV and coated with thiolated low molecular weight hyaluronic acid were formulated to improve both the solubility and the residential time in the conjunctival sac of the loaded drug IND. The NPs were prepared through the ionotropic gelation technique, exploiting the interaction between the positively charged amino group of CS and the negatively charged sulfonic group of SBE-β-CD. The mucoadhesive properties of the NPs were evaluated on chicken trachea and esophagus tissues using a texture analyser. The irritability effects of NPs were disclaimed with Hecam test. The developed coated NPs showed increased residential time in the conjunctival sac, displayed no irritancy or toxicity for local administration, making them an optimal and innovative drug delivery system for the treatment of anterior segment inflammation diseases. On the other hand, the uncoated NPs displayed better permeating properties since they are smaller and could be further exploited for the treatment of posterior segment diseases.

Poly(2-hydroxyethyl methacrylate-co-quaternary ammonium salt chitosan) hydrogel: A potential contact lens material with tear protein deposition resistance and antimicrobial activity

Tear protein deposition resistance and antimicrobial property are two challenges of conventional poly(2-hydroxyethyl methacrylate) (pHEMA) contact lenses. In this work, we developed a poly(2-hydroxyethyl methacrylate-co-quaternary ammonium salt chitosan) hydrogel, named as p(HEMA-co-mHACC) hydrogel, using acryloyl HACC (mHACC) as a macromolecular crosslinker. With increasing the acryloyl substitution degree (14-29%) or mHACC content (2-11%), the hydrogel showed an enhanced tensile strength (432-986 kPa) and Young's modulus (360-1158 kPa), a decreased elongation at break (242-84%), and an increased visible light transmittance (0-95%). At an optimal acryloyl substitution degree of 26%, with the increase of mHACC content from 2% to 11%, p(HEMA-co-mHACC) hydrogel presented a decreased water contact angle from 84.6 to 55.3 degree, an increased equilibrium water content from 38% to 45%, and an enhanced oxygen permeability from 8.5 to 13.5 barrer. Due to the enhancement in surface hydrophilicity and electropositivity, p(HEMA-co-mHACC) hydrogel remarkably reduced the deposition of lysozyme, but little affected the adsorption of BSA, depending on the hydrophilic/hydrophobic and electrostatic interactions. The antimicrobial test against Staphylococcus aureus and Escherichia coli showed that p(HEMA-co-mHACC) hydrogel presented an 8-32 times higher germicidal ability than pHEMA hydrogel, indicative of a better antimicrobial activity. The in vitro cell culture of mouse NIH3T3 fibroblasts and immortalized human keratinocytes showed that p(HEMA-co-mHACC) hydrogel was non-toxic. Thus, p(HEMA-co-mHACC) hydrogel with tear protein deposition resistance and antimicrobial activity is a potential candidate for contact lenses.

A Meta-Analysis of Wearable Contact Lenses for Medical Applications: Role of Electrospun Fiber for Drug Delivery

In recent years, wearable contact lenses for medical applications have attracted significant attention, as they enable continuous real-time recording of physiological information via active and noninvasive measurements. These devices play a vital role in continuous monitoring of intraocular pressure (IOP), noninvasive glucose monitoring in diabetes patients, drug delivery for the treatment of ocular illnesses, and colorblindness treatment. In specific, this class of medical devices is rapidly advancing in the area of drug loading and ocular drug release through incorporation of electrospun fibers. The electrospun fiber matrices offer a high surface area, controlled morphology, wettability, biocompatibility, and tunable porosity, which are highly desirable for controlled drug release. This article provides an overview of the advances of contact lens devices in medical applications with a focus on four main applications of these soft wearable devices: (i) IOP measurement and monitoring, (ii) glucose detection, (iii) ocular drug delivery, and (iv) colorblindness treatment. For each category and application, significant challenges and shortcomings of the current devices are thoroughly discussed, and new areas of opportunity are suggested. We also emphasize the role of electrospun fibers, their fabrication methods along with their characteristics, and the integration of diverse fiber types within the structure of the wearable contact lenses for efficient drug loading, in addition to controlled and sustained drug release. This review article also presents relevant statistics on the evolution of medical contact lenses over the last two decades, their strengths, and the future avenues for making the essential transition from clinical trials to real-world applications.

Challenges and solutions in polymer drug delivery for bacterial biofilm treatment: A tissue-by-tissue account

To tackle the emerging antibiotic resistance crisis, novel antimicrobial approaches are urgently needed. Bacterial communities (biofilms) are a particular concern in this context. Biofilms are responsible for most human infections and are inherently less susceptible to antibiotic treatments. Biofilms have been linked with several challenging chronic diseases, including implant-associated osteomyelitis and chronic wounds. The specific local environments present in the infected tissues further contribute to the rise in antibiotic resistance by limiting the efficacy of systemic antibiotic therapies and reducing drug concentrations at the infection site, which can lead to reoccurring infections. To overcome the shortcomings of systemic drug delivery, encapsulation within polymeric carriers has been shown to enhance antimicrobial efficacy, permeation and retention at the infection site. In this Review, we present an overview of current strategies for antimicrobial encapsulation within polymeric carriers, comparing challenges and solutions on a tissue-by-tissue basis. We compare challenges and proposed drug delivery solutions from the perspective of the local environments for biofilms found in oral, wound, gastric, urinary tract, bone, pulmonary, vaginal, ocular and middle/inner ear tissues. We will also discuss future challenges and barriers to clinical translation for these therapeutics. The following Review demonstrates there is a significant imbalance between the research focus being placed on different tissue types, with some targets (oral and wound biofims) being extensively more studied than others (vaginal and otitis media biofilms and endocarditis). Furthermore, the importance of the local tissue environment when selecting target therapies is demonstrated, with some materials being optimal choices for certain sites of bacterial infection, while having limited applicability in others.

Polymeric Nanoparticles and Chitosan Gel Loading Ketorolac Tromethamine to Alleviate Pain Associated with Condyloma Acuminata during the Pre- and Post-Ablation

This study describes the preparation and evaluation of two formulations, a hydrogel and a nanostructured system, containing ketorolac tromethamine as an anti-inflammatory agent for the local therapy against the inflammatory process derived from the surgical excision of Condyloma acuminata. Both formulations were physicochemically characterized. In vitro release profiles show that the nanoparticles release 92% ± 2.3 of the total ketorolac tromethamine encapsulated, while the chitosan gel releases 18.6% ± 0.2. The ex vivo permeation and distribution through human skin were also assayed and was observed how the main amount of ketorolac tromethamine is retained in the epidermis. In vivo studies were accomplished to evaluate the anti-inflammatory efficacy in mice which also involved the histological analysis to confirm the in vivo results. The nanoparticles present a significantly higher anti-inflammatory efficacy than chitosan gel. The tolerability of developed formulations was assessed by monitoring the biomechanical properties of the skin before and after application of both formulations. No statistical differences in trans-epidermal water loss and skin hydration with respect to the basal values were observed and the formulations exhibited higher anti-inflammatory activity compared to a reference ketotorlac tromethamine solution. Therefore, it can be concluded that both formulations can be proposed as outstanding candidates for offering a local anti-inflammatory therapeutical tool with potential clinical application.

Nonsteroidal anti-inflammatory drugs for retinal neurodegenerative diseases

Nonsteroidal anti-inflammatory drugs (NSAIDs) are among the most common prescription drugs for inflammation, and topical NSAIDs are often used in ophthalmology to reduce pain, photophobia, inflammation, and edema. In recent years, many published reports have found that NSAIDs play an important role in the treatment of retinal neurodegenerative diseases, such as age-related macular degeneration (AMD), diabetic retinopathy (DR), glaucoma, pathological myopia, and retinitis pigmentosa (RP). The aim of the current review is to provide an overview of the role of various NSAIDs in the treatment of retinal neurodegenerative diseases and the corresponding mechanisms of action. This review highlighted that the topical application of NSAIDs for the treatment of retinal degenerative diseases has been studied to a remarkable extent and that its beneficial effects in many diseases have been proven. In the future, prospective studies with large study populations are required to extend these effects to clinical settings.

Application of Dimethyl Sulfoxide as a Therapeutic Agent and Drug Vehicle for Eye Diseases

Dimethyl sulfoxide (DMSO) is an amphipathic molecule widely used as a solvent for water-insoluble substances, cryopreserving, and cell-biological therapies. It has known properties as an inducer of cellular differentiation, a free radical scavenger, and a radioprotectant. In addition, DMSO is used for its various therapeutic and pharmaceutical properties, such as anti-inflammatory, local and systemic analgesic, antibacterial, antifungal, antiviral, and membrane penetration enhancement agents. DMSO treatment can be given orally, intravenously, or topically for a wide range of indications. The administration of DMSO exhibits favorable outcomes in human eye diseases with low to none observed ocular or systemic ocular toxicity. Nevertheless, DMSO is an essential and nonpatentable potential therapeutic agent that remains underexplored and ignored by pharmaceutical developers and ophthalmologists. This current review takes data from experimental and clinical studies that have been published to substantiate the potential therapeutic efficacy of DMSO and stimulate the research of its application in clinical ophthalmology. Given that DMSO is inexpensive, safe, and easily formulated into therapeutic medicinal products and conventional ophthalmological drugs, this compound should be further explored and studied in the treatment of a variety of acute and chronic ocular disorders.

Studies on Surfactants, Cosurfactants, and Oils for Prospective Use in Formulation of Ketorolac Tromethamine Ophthalmic Nanoemulsions

Nanoemulsions (NE) are isotropic, dispersions of oil, water, surfactant(s) and cosurfactant(s). A range of components (11 surfactants, nine cosurfactants, and five oils) were investigated as potential excipients for preparation of ketorolac tromethamine (KT) ocular nanoemulsion. Diol cosurfactants were investigated for the effect of their carbon chain length and dielectric constant (DEC), Log P, and HLB on saturation solubility of KT. Hen's Egg Test-ChorioAllantoic Membrane (HET-CAM) assay was used to evaluate conjunctival irritation of selected excipients. Of the investigated surfactants, Tween 60 achieved the highest KT solubility (9.89 ± 0.17 mg/mL), followed by Cremophor RH 40 (9.00 ± 0.21 mg/mL); amongst cosurfactants of interest ethylene glycol yielded the highest KT solubility (36.84 ± 0.40 mg/mL), followed by propylene glycol (26.23 ± 0.82 mg/mL). The solubility of KT in cosurfactants was affected by four molecular descriptors: carbon chain length, DEC, log P and HLB. KT solubility was directly proportional to DEC and the HLB yet, inversely proportional to carbon chain length and log P. All surfactants, except Labrasol ALF, were non-irritant. The majority of cosurfactants were slightly irritant, butylene glycol was a moderate irritant, pentylene and hexylene glycols were strong irritants. These findings will inform experiments aimed at developing NE formulations for ocular administration of KT.

Design and evaluation of pharmaceutical availability, stability and quality of modified viscosity eye drops with choline salicylate

These studies investigate the possibility of developing and using choline salicylate (CS) in ophthalmic therapy in the form of eye drops with increased viscosity. A 0.5% addition of hydroxypropyl methylcellulose (HPMC) was used as the viscosity increasing agent. The ability of CS to cross a hydrophilic membrane (regenerated cellulose membrane) was assessed by determining a rate constant consistent with zero order kinetics. In studies on a porcine cornea, the ability of CS to penetrate into the structure of the cornea was confirmed by determining the content of CS in the cornea after 5 minutes and 3 hours exposure to eye drops. The quality parameters of eye drops were assessed: pH, viscosity, osmolarity and microbiological purity. Stability tests were also performed on eye drops stored in unit minims packaging and in multi-dose bottle packaging. The following storage conditions were adopted: 40°C/75% RH, 25°C/60% RH, 2-8°C. The sensitivity of CS to light was also confirmed. The UV and HPLC-UV methods were used to assess the CS content, while the HPLC-UV and HPLC-MS/MS methods were used to assess the chromatographic purity.

The potential of lipid mediator networks as ocular surface therapeutics and biomarkers

In the last twenty years an impressive body of evidence in diverse inflammatory animal disease models and human tissues, has established polyunsaturated fatty acids (PUFA) derived specialized-pro-resolving mediators (SPM), as essential mediators for controlling acute inflammation, immune responses, wound healing and for resolving acute inflammation in many non-ocular tissues. SPM pathways and receptors are highly expressed in the ocular surface where they regulate wound healing, nerve regeneration, innate immunity and sex-specific regulation of auto-immune responses. Recent evidence indicates that in the eye these resident SPM networks are important for maintaining ocular surface health and immune homeostasis. Here, we will review and discuss evidence for SPMs and other PUFA-derived mediators as important endogenous regulators, biomarkers for ocular surface health and disease and their therapeutic potential.

Effects of topical instillation of 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, and 0.03% flurbiprofen sodium on corneal sensitivity in ophthalmologically normal cats

OBJECTIVE

To investigate the effects of short-term and prolonged topical instillation of 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, and 0.03% flurbiprofen sodium on corneal sensitivity (CS) in ophthalmologically normal cats.

ANIMALS

12 healthy adult domestic shorthair cats.

PROCEDURES

In the first of 2 study phases, each cat received 0.1% diclofenac sodium, 0.5% ketorolac tromethamine, 0.03% flurbiprofen sodium, and saline (0.9% NaCl; control) solutions (1 drop [0.05 mL]/eye, q 5 min for 5 treatments) in a randomized order with a 2-day washout period between treatments. For each cat, an esthesiometer was used to measure CS before treatment initiation (baseline) and at 15, 30, 45, and 60 minutes after the last dose. There was a 2-day washout period between phases. The second phase was similar to the first, except each treatment was administered at a dosage of 1 drop/eye, twice daily for 5 days and CS was measured before treatment initiation and at 15 minutes and 24 and 48 hours after the last dose. The Friedman test was used to evaluate change in CS over time.

RESULTS

None of the 4 treatments had a significant effect on CS over time in either study phase.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that neither short-term nor prolonged topical instillation of 3 NSAID ophthalmic solutions had any effect on the CS of healthy cats. Given potential differences in cyclooxygenase expression between healthy and diseased eyes, further investigation of the effects of topical NSAID instillation in the eyes of cats with ocular surface inflammation is warranted.

Diclofenac Sodium Triggers p53-Dependent Apoptosis in Human Corneal Epithelial Cells via ROS-Mediated Crosstalk

Diclofenac sodium (DFS), a nonsteroidal anti-inflammatory drug, is frequently used in ophthalmology, but it causes negative effects on corneas. The mechanisms underlying the toxicities to corneas remains unclear. The present study was designed to assess the cytotoxicity of DFS to human corneal epithelial (HCEP) cells in vitro and further investigate its related mechanisms. The HCEP cells were treated with DFS at different concentrations ranging from 0.003 125% to 0.1%. DFS showed a dose- and time-dependent cytotoxicity to HCEP cells including abnormal morphology and declined viability. The 0.05% DFS-treated HCEP cells presented cell cycle arrest at S phase, reactive oxygen species (ROS) overproduction, and positive staining of phosphorylated H2AX, suggesting that DFS caused ROS-mediated DNA damage. The upregulation of p53 expression, formation of apoptotic body, phosphatidylserine externalization, and DNA ladder demonstrated that the p53-dependent apoptosis pathway was involved in the cytotoxicity of DFS. Furthermore, DFS activated caspase-8, caspase-9, and caspase-3 altered the expression levels of Bcl-2 family proteins including tBid, Bax, and Bcl-2, as well as increased poly(ADP-ribose) polymerase (PARP) cleavage. DFS also induced ΔΨm disruption, resulting in the release of cytochrome c and apoptosis-inducing factor into the cytoplasm. Additionally, the DFS-induced apoptosis was alleviated by p53 inhibitor. Taken together, DFS triggered p53-dependent apoptosis in HCEP cells via ROS-mediated crosstalk between the extrinsic and intrinsic pathways.

An ex vivo skin model to probe modulation of local cutaneous arachidonic acid inflammation pathway

There is a need for inexpensive and reliable means to determine the modulation of cutaneous inflammation. The method outlined in this article draws together a number of scientific techniques and makes use of generally unwanted biological tissues as a means of determining skin inflammation ex vivo, and focuses on probing aspects of the arachidonic acid inflammation pathway. Freshly excised skin contains elevated levels of short-lived inducible cyclooxygenase-2 (COX-2) and, under viable conditions, COX-2 and its eicosanoid products will continue to be produced until tissue necrosis, providing a window of time in which relative levels can be probed to determine exacerbation due to an upregulating factor or downregulation due the presence of an agent exerting anti-inflammatory activity. Ex vivo porcine skin, mounted in Franz diffusion cells, is dosed topically with the xenobiotic challenge and then techniques such as Western blotting and immunohistochemistry can then be used to probe relative COX-2 levels on a semi-quantitative or qualitative level. Enzyme-linked immunosorbent assay or LCMS can be used to determine relative prostaglandin E-2 (PGE-2) levels. Thus far, the technique has been used to examine the effects of topically applied anti-inflammatories (betamethasone, ibuprofen, ketoprofen and methotrexate), natural products (fish oil, Devil’s claw extract and pomegranate rind extract) and drug delivery vehicle (polyNIPAM nanogels). Topically applied xenobiotics that modulate factors such as COX-2 and PGE-2 must penetrate the intact skin, and this provides direct evidence of overcoming the "barrier function" of the stratum corneum in order to target the viable epidermis in sufficient levels to be able to elicit such effects. This system has particular potential as a pre-clinical screening tool for those working on the development of topical delivery systems, and has the additional advantage of being in line with 3 Rs philosophy.

[Nonsteroidal anti-inflammatory drugs in the treatment of anterior uveitis associated with spondyloarthritis]

Anterior uveitis (AU) is one of the common extraskeletal manifestations of spondyloarthritis (SpA). The course of AU in patients with SpA is characterized by frequent relapses. The article considers the question of local and systemic use of nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment and prevention of SpA-associated uveitis exacerbations.

Design, fabrication, and characterization of graft co-polymer assisted ocular insert: a state of art in reducing post-operative pain

PURPOSE

Targeted delivery of drugs at appropriate concentrations to ocular tissues is required to avoid wastage. Hence, advanced systems that maximize the release of poorly soluble drugs and deliver them at ocular sites must be designed.

METHODS

In this study, Soluplus^® (polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol-graft copolymer) was selected as a solubilizer as well as film former for preparing ocular inserts and polyethylene glycol 400 (PEG-400) as a plasticizer. On the basis of an initial phase solubility study, the maximum concentration of Soluplus^® possible was used for developing the inserts. An optimized formulation was obtained using a 3²-factorial design. Two factors at three levels were used to design the ocular inserts. Soluplus^® (X ₁) and the plasticizer, PEG-400 (X ₂), were set as the independent variables at various levels, and the Rel_4h (drug release in 4 h, Y ₁) and tensile strength (Y ₂) were set as the dependent variables. A pre-formulation study was conducted to select suitable materials.

RESULTS

Various physico-chemical parameters of the optimized formulation, including the tensile strength and folding endurance, were studied using FT-IR, DSC, XRD, and SEM. An in vitro dissolution study was conducted to determine the amount of drug released. There was no redness, swelling, or watering of the rabbit eye.

CONCLUSION

It was concluded that the ocular inserts of the poorly soluble nepafenac developed using a graft-co-polymer enhanced the solubility and utilization of the drug for a prolonged period.

Recent progress and strategies to develop antimicrobial contact lenses and lens cases for different types of microbial keratitis

Although contact lenses are widely used for vision correction, they are also the primary cause of a number of ocular diseases such as microbial keratitis (MK), etc. and inflammatory events such as infiltrative keratitis (IK), contact lens acute red eye (CLARE), contact lens-induced peripheral ulcer (CLPU), etc. These diseases and infiltrative events often result from microbial contamination of lens care solutions and lens cases that can be exacerbated by unsanitary lens care and extended lens wear. The treatment of microbial biofilms (MBs) on lens cases and contact lenses are complicated and challenging due to their resistance to conventional antimicrobial lens care solutions. More importantly, MK caused by MBs can lead to acute visual damage or even vision impairment. Therefore, the development of lens cases, lens care solutions, and contact lenses with effective antimicrobial performance against MK will contribute to the safe use of contact lenses. This review article summarizes and discusses different chemical approaches for the development of antimicrobial contact lenses and lens cases employing passive surface modifications, antimicrobial peptides, free-radical fabricating agents, quorum sensing quenchers, antibiotics, antifungal drugs and various metals and coatings with antimicrobial nanomaterials. The benefits and shortcomings of these approaches are assessed, and alternative solutions for future developments are discussed.

Combination Antioxidant/NSAID Therapies and Oral/Topical Ocular Delivery Modes for Prevention of Oxygen-Induced Retinopathy in a Rat Model

Given the complexity of oxygen-induced retinopathy (OIR), we tested the hypothesis that combination therapies and modes of administration would synergistically optimize efficacy for prevention of OIR. Newborn rats were exposed to neonatal intermittent hypoxia (IH) from the first day of life (P0) until P14 during which they received: (1) oral glutathione nanoparticles (nGSH) with topical ocular phosphate buffered saline (PBS); (2) nGSH with topical ocular Acuvail (ACV); (3) oral coenzyme Q10 (CoQ10) + ACV; (4) oral omega 3 polyunsaturated fatty acids (n-3 PUFAs) + ACV; (5) CoQ10 + n-3 PUFAs + PBS; or (6) CoQ10 + n-3 PUFAs + ACV. Treated groups raised in room air (RA) served as controls. At P14, pups were placed in RA with no treatment until P21. Retinal vascular pathology, ocular angiogenesis biomarkers, histopathology, and morphometry were determined. All combination treatments in IH resulted in the most beneficial retinal outcomes consistent with suppression of angiogenesis growth factors during reoxygenation/reperfusion and no significant adverse effects on somatic growth. nGSH + PBS also reversed IH-induced retinopathy, but had negative effects on growth. Simultaneously targeting oxidants, inflammation, and poor growth mitigates the damaging effects of neonatal IH on the developing retina. Therapeutic synergy with combination delivery methods enhance individual attributes and simultaneously target multiple pathways involved in complex diseases such as OIR.

Recent Advances in the Design of Topical Ophthalmic Delivery Systems in the Treatment of Ocular Surface Inflammation and Their Biopharmaceutical Evaluation

Ocular inflammation is one of the most common symptom of eye disorders and diseases. The therapeutic management of this inflammation must be rapid and effective in order to avoid deleterious effects for the eye and the vision. Steroidal (SAID) and non-steroidal (NSAID) anti-inflammatory drugs and immunosuppressive agents have been shown to be effective in treating inflammation of the ocular surface of the eye by topical administration. However, it is well established that the anatomical and physiological ocular barriers are limiting factors for drug penetration. In addition, such drugs are generally characterized by a very low aqueous solubility, resulting in low bioavailability as only 1% to 5% of the applied drug permeates the cornea. The present review gives an updated insight on the conventional formulations used in the treatment of ocular inflammation, i.e., ointments, eye drops, solutions, suspensions, gels, and emulsions, based on the commercial products available on the US, European, and French markets. Additionally, sophisticated formulations and innovative ocular drug delivery systems will be discussed. Promising results are presented with micro- and nanoparticulated systems, or combined strategies with polymers and colloidal systems, which offer a synergy in bioavailability and sustained release. Finally, different tools allowing the physical characterization of all these delivery systems, as well as in vitro, ex vivo, and in vivo evaluations, will be considered with regards to the safety, the tolerance, and the efficiency of the drug products.

Comparison of the efficacy of nepafenac 0.1% in quiescent Behçet's uveitis and non-uveitic healthy patients after phacoemulsification surgery

PURPOSE

To compare the efficacy of nepafenac on anterior chamber flare and intraocular pressure(IOP) in healthy (group 1) and uveitic eyes (group 2) undergoing cataract surgery.

METHODS

A retrospective, consecutive case series study.

RESULTS

Among 54 the patients, 14 had a history of uveitis. The groups were similar in age and gender. There were significant changes in flare values in both groups. When the temporal changes of flare values were compared, there was no difference between the two groups. There were no significant changes in IOP values in both group. When the temporal changes of IOP values were compared, there was no difference between the groups.

CONCLUSIONS

Nepafenac 0.1% has been shown to be effective in suppressing inflammation after cataract surgery in uveitic eyes as well as in healthy eyes. In addition, it has been observed that it does not increase intraocular pressure in both healthy and uveitic eyes and it is safe to use with this regard.

Ocular nonsteroidal inflammatory drugs: where do we stand today?

Since their first introduction in ophthalmology, the use of NSAIDs (nonsteroidal anti-inflammatory drugs) has been exponentially expanded, with numerous therapeutic applications. Despite their controversial history, they have proven their efficacy as anti-inflammatory agents in a variety of diseases. Nowadays, NSAIDs are part of surgical protocols of the most commonly performed ophthalmic operations, such as cataract or ocular surgery. They are universally implicated in the management of conjunctivitis, retinal and choroidal disease and miscellaneous inflammatory diseases. Moreover, although linked with serious adverse events and toxicities, their therapeutic magnitude in Ophthalmology should not be affected. This review systematically portrays the variety of ocular NSAIDs available to date, along with their differences in their way of action, indications and potential side effects in various ophthalmologic conditions.

The Therapeutic Effects and Possible Mechanism of Pranoprofen in Mouse Model of Corneal Alkali Burns

Objective

To investigate therapeutic effects and possible mechanism of pranoprofen in a mouse model of corneal alkali burns and provide new evidence for the clinical treatment of corneal alkali burns.

Methods

A unilateral alkali burn was created in the central cornea by placing a piece of 2 mm diameter filter paper soaked in 1N NaOH on the right eye for 30 seconds. After the model was performed, C57BL/6J mice received topical treatment with saline eye drops or pranoprofen eye drops and were, respectively, categorized as saline group and pranoprofen group, whereas the remaining normal mice that were not subjected to alkali burns served as control, each group containing 15 mice (n = 45). On the 5th day after model establishment, the corneal fluorescein sodium staining score was evaluated in order to assess corneal epithelial damage. Tissue HE stain was used to observe the pathological changes of corneal tissue in each group. Real-time RT-PCR and western blot were also performed to detect the mRNA and protein expression of NLRP3, IL-1β/p17, and matrix metallopeptidase MMP-13.

Results

5 days after burns, microscopic observations of the pranoprofen group showed less corneal opacity and neovascularization development than the saline group. Sodium fluorescein staining showed obvious corneal structure disorders, poor corneal epithelium continuity, and a larger corneal epithelial defect area in the saline group (10.33±+−0.57) as opposed to the pranoprofen group (8.33 ± 0.57） (p < 0.05). HE stain results showed the saline group had obvious corneal structure disorder and the corneal epithelial layer was incomplete as opposed to the pranoprofen group. PCR and western blot results suggested that the pranoprofen group expressed less NLRP3, IL-1β, and MMP-13 mRNA and protein expression in corneal tissue than the saline group (p < 0.05).

Conclusion

Pranoprofen may alleviate inflammatory response by inhibiting the expression levels of NLRP3 and IL-1β at the early stage of corneal alkali injury, lowering the expression of MMP-13 and ultimately reducing corneal epithelial damage.

Pain Following the Use of Anesthesia Formulation Among Individuals Undergoing Cataract Surgery: A Randomized Controlled Trial

Purpose

To assess the pain intensity of two intracameral anesthetic solutions in patients undergoing cataract surgery and evaluate the factors influencing the patients’ postoperative activities.

Methods

Sixty-two patients undergoing cataract surgery were randomized to receive the study drug – a manufactured solution of 0.02% tropicamide/0.31% phenylephrine/1% lidocaine (Mydrane) or a traditional anesthetic formulation - solution of 1% lidocaine/0.025% adrenaline as an intraocular anesthetic. The pain intensity was assessed by Visual Analog Scale for Pain (VAS Pain) and Brief Pain Inventory-short form (BPI) on the next day after the surgery.

Results

The mean pain score measured preoperatively with VAS Pain was 0.34 in Mydrane group and 0.09 in the reference group (p = 0.51). There were no statistically significant differences between the two anesthetic methods with respect to pain intensity during the surgery (p = 0.94) and the influence of pain during the last 24 h on activity (p = 0.79), mood (p = 0.31), social contacts (p = 0.29), sleep (p = 0.5) and the joy of life (p = 0.39). Additionally, there was no statistically significant influence of age, sex, lateralization, co-existing ophthalmological diseases (p = 0.98) and post-operative complications (p = 0.4) on the experienced pain measured during the surgery and in the last 24 h.

Conclusions

New commercially available intraocular anesthetic solution (Mydrane™) seems to be as effective as off-label traditional anesthetic formulation, in reducing the pain experienced during cataract surgery under topical anesthesia.

Characterisation of 2-HP-β-cyclodextrin-PLGA nanoparticle complexes for potential use as ocular drug delivery vehicles

Aim: 2-HP-β-cyclodextrin-PLGA nanoparticle complexes were prepared to enhance the aqueous humour delivery of Triamcinolone acetonide.Materials & methods: Drug-loaded 2-HP-β-CD/PLGA nanoparticle complexes prepared by adapting a quasi-emulsion solvent evaporation technique. In vitro drug release, in vitro transcorneal permeation study, histopathological study and in vivo transcorneal penetration of PLGA nanoparticles and 2-HP-β-CD/PLGA nanoparticle complexes were evaluated. Results: Particle size distributions of 2-HP-β-CD/PLGA nanoparticle complexes were 149.4 ± 3.7 nm and presented stable system. Corneal penetration studies revealed steady sustained drug release (First-order); 2-HP-β-CD/PLGA nanoparticle complexes increased ocular bioavailability by increasing dispersion in the tear film and improving drug release. Conclusion: 2-HP-β-CD/PLGA nanoparticle complex formulation is a promising alternative to conventional eye drops.

Effect of 0.1% Bromfenac for Preventing Macular Edema after Cataract Surgery in Patients with Diabetes

Purpose

To investigate the effect of 0.1% bromfenac sodium hydrate ophthalmic solution for prevention of macular edema after cataract surgery in patients with diabetes.

Methods

A retrospective analysis of 75 patients with diabetes who underwent cataract surgery was performed. Thirty-eight patients (52 eyes) were instilled with 0.1% bromfenac solution (bromfenac group) and 37 patients (46 eyes) were not (control group).

Results

There were no significant preoperative between-group differences. Compared to the control group, at 1 month after surgery, the bromfenac group showed slightly better best-corrected visual acuity (0.12 ± 0.12 vs. 0.32 ± 0.42, p = 0.142), lower central macular thickness (265.58 ± 31.28 vs. 314.15 ± 76.11 µm, p < 0.001), and lower macular volume (8.46 ± 0.60 vs. 9.14 ± 1.53 mm³, p = 0.022). There were no significant differences between the two groups at 4 and 6 months postoperatively (p > 0.05). Mean changes in central macular thickness showed significant differences at 1 and 4 months postoperatively (−1.44 ± 11.72 and 10.44 ± 22.48 µm in bromfenac group vs. 47.19 ± 70.24 and 31.69 ± 48.04 µm in control group, p < 0.001 and p = 0.016) and mean changes in macular volume showed a significant difference at 1 month postoperatively (−0.08 ± 0.47 mm³ in bromfenac group vs. 0.58 ± 1.28 mm³ in control group, p < 0.001). There were no significant differences thereafter (p > 0.05).

Conclusions

Treatment with 0.1% bromfenac sodium hydrate ophthalmic solution showed good efficacy for preventing cystoid macular edema early after cataract surgery in patients with diabetes.

Development of an Anti-Inflammatory Drug-Incorporated Biomimetic Scaffold for Corneal Tissue Engineering

Purpose: The aim of this study was to design naproxen sodium (NS)-containing, biomimetic, porous poly(lactide-co-glycolide) (PLGA) scaffolds for regeneration of damaged corneal epithelium. Methods: NS-incorporated PLGA scaffolds were prepared using the emulsion freeze-drying method and then coated with collagen or poly-l-lysine. Porosity measurements of the scaffolds were performed by the gas adsorption/desorption method and the scaffolds demonstrated highly porous, open-cellular pore structures with pore sizes from 150 to 200 μm. Results: The drug loading efficiency of scaffolds was found to be higher than 84%, and about 90%-98% of NS was released at the end of 7 days with a fast drug release rate at the initial period of time and then in a slow and sustained manner. The corneal epithelial cells were isolated from New Zealand white rabbits. The obtained cells were seeded onto scaffolds and continued to increase during the time period of the study, indicating that the scaffolds might promote corneal epithelial cell proliferation without causing toxic effects for at least 10 days. Conclusions: The NS-loaded PLGA scaffolds exhibited a combination of controlled drug release and biomimetic properties that might be attractive for use in treatment of corneal damage both for controlled release and biomedical applications.

Bimatoprost Imprinted Silicone Contact Lens to Treat Glaucoma

Bimatoprost is widely used for the management of glaucoma. Currently, it is delivered via eye drop solution, which is highly inefficient due to low bioavailability. To control the release of ocular drugs, contact lenses are used by scientists. However, the conventional soaking method showed high burst release due to absence of any efficient controlling membrane. The objective of the paper was to apply molecular imprinting technology to improve the loading of bimatoprost from the soaking solution and to sustain the release of drug from the contact lens. The bimatoprost was loaded by conventional soaking method (BT-SM) and compared with the molecular imprinted contact lenses (BT-MP). The loading of bimatoprost by molecular imprinting technology affect the swelling of the contact lens; however, the batch BT-MP-10 did not showed significant alterations. The uptake study showed improvement in the bimatoprost loading by molecular imprinting technology in comparison to the conventional soaking technology. The in vitro bimatoprost release data showed improvement in the bimatoprost release rate profiles with BT-MP contact lenses (up to 36-60 h) lenses in comparison to BT-SM contact lenses (up to 24-36 h). The in vivo rabbit tear fluid data with BT-MP batch showed improvement in the bimatoprost retention time in comparison to BT-SM contact lens and eye drop solution. The rabbit model failed to respond bimatoprost; thus, the efficacy studies need to be conducted on canines or human primates. The paper revealed the potential of using molecular imprinting technology to improve the uptake of bimatoprost and to achieve sustain release kinetics without altering the swelling, transmittance and folding endurance properties of the contact lens.

Choline Salicylate Analysis: Chemical Stability and Degradation Product Identification

Choline salicylate (CS) as a derivative of acetylsalicylic acid is commonly used in different drug forms. In medicine, it is applied topically to inflammation of the oral cavity mucosa and in laryngology. However, this substance in the form of an ionic liquid has not been investigated enough. There are no literature studies on stability tests constituting a stage of pre-formulation research. HPLC (Nucleosil C18, 4.6 × 150 mm, 5 μm; methanol-water-acetic acid 60:40:1, 230 nm or 270 nm) and UV (276 nm) methods for the determination of CS in 2% (g/mL) aqueous solutions were developed. Under stress conditions, CS susceptibility to hydrolytic degradation in aqueous medium, hydrochloric acid, sodium hydroxide, and hydrogen peroxide, and the effect of light on the stability of CS solutions were studied with HPLC analysis. The degradation degree of CS and the purity of the solutions were also tested. Choline salicylate has been qualified as practically stable in neutral and acid media, stable in an alkaline medium, very stable in an oxidizing environment, and photolabile in solution. The HPLC-MS/MS method was used to identify 2,3- and 2,5-dihydroxybenzoic acids as degradation products of CS under the tested conditions.

Preparation and Evaluation of Eudragit® L100 Nanoparticles Loaded Impregnated with KT Tromethamine Loaded PVA -HEC Insertions for Ophthalmic Drug Delivery

Purpose: The purpose of the present study was to improve the ocular delivery for ketorolac tromethamine (KT) used to treat inflammation of the eye.

Methods: Eudragit nanoparticles loaded with KT were prepared and incorporated in polyvinyl alcohol (PVA) and hydroxyethyl cellulose (HEC) films. Nanoparticles were characterized by Fourier transform-infrared (FT-IR), scanning electron microscopy (SEM). Physicochemical properties and encapsulation effciency were investigated for nanoparticles. Also, the inserts were evaluated for their physiochemical parameters like percentage moisture absorption, percentage moisture loss, thickness and folding endurance.

Results: Mean particle size and zeta potential were in range of 153.8-217 nm and (-10.8) - (-40.7) mV, respectively. The results show that the use of a surfactant has not led to any major change on drug loading. The loading increases with the amount of polymer. The insert had a thickness varying from 0.072 ± 0.0098 to 0.0865 ± 0.0035 mm. The thicknesses of the inserts and the folding endurance increased with the total polymer concentration. The physicochemical properties showed that the Eudragit® L-100 nanoparticles loaded PVA-HEC films could be an effective carrier for KT.

Conclusion: For the first time, inserts of Eudragit nanoparticles were successfully prepared for ophthalmic drug delivery system to prevent frequent drug administration and enhance patient compliance.

Optimization of the Interaction between Diclofenac and Ibuprofen with Benzalkonium Chloride to Prepare Ocular Nanosuspension

BACKGROUND

Non-steroidal anti-inflammatory drugs are most commonly used in the management of ocular inflammations. These drugs have poorly aqueous solubility and weakly acidic nature. They interact with cationic quaternary ammonium compound benzalkonium chloride, used as a preservative in ophthalmic formulations, to form insoluble complexes. To overcome this incompatibility solubilizers like polysorbate 80, lysine salts, tocopheryl polyethylene glycol succinate etc. are used which are quite irritating and affect the corneal integrity.

OBJECTIVE

The objective of the present study is to formulate nonirritating, compatible, microbiologically stable ophthalmic formulation with good corneal permeation characteristics. The interaction between diclofenac sodium or ibuprofen with benzalkonium chloride was optimized using a central composite experimental design to prepare nanosuspensions by nanoprecipitation.

METHODS

The optimized batches of nanosuspensions were evaluated for ex vivo corneal permeation study, preservative challenge test and physical stability. The optimal concentrations of benzalkonium chloride for diclofenac sodium (0.1%, w/v) and ibuprofen (0.1% w/v) nanosuspensions were determined to be 0.002%(w/v), which had a respective average particle size of 440 nm and 331 nm, respectively. The nanosuspensions of diclofenac sodium and ibuprofen provided 1.6 and 2.1- fold higher ex vivo corneal permeation than their respective conventional aqueous solution dosage forms. Further, the concentration of benzalkonium chloride used in the formulations showed adequate preservative efficacy.

RESULTS

The optimized nanosuspension formulations of diclofenac and ibuprofen were found to be physically stable and microbiologically safe with greater corneal penetration than the conventional solution dosage forms.

The anti-fibrotic and anti-inflammatory effects of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b] pyriine-3-carbonitrile in corneal fibroblasts

BACKGROUND

Although several studies had addressed the anti-inflammatory effects of derivatives of 4H-chromene and chromeno[2,3-b]pyridine in the different types of cells, whether these derivatives would exert beneficial anti-fibrotic effects during corneal fibrotic scar formation was unclear.

METHODS

We examined the cyclooxygenase-2 (COX-2) expression of 2,4-diamino-5-(1-hydroxynaphthalen-2-yl)-5H-chromeno[2,3-b]pyridine-3-carbonitrile (N1) in the human corneal fibroblasts (HCFs) under the treatment TGF-β1. Signaling pathways underlying the mechanism of the N1 effect on the HCFs were determined.

RESULTS

Application of N1 significantly decreased COX-2 expression after 2 h and 4 h in the HCFs stimulated with TGF-β1. Notably, reduced production of extracellular matrix proteins under N1 treatment was found, including fibronectin, collagen I, and matrix metallopeptidase 9. Immunoblot analysis showed that treatment with N1 significantly attenuated phosphorylation of both STAT3 and Smad 2 in the TGF-β1-stimulated HCFs. Upregulated mRNA of Smad2 and downregulated mRNA of Smad3 were observed using the quantitative real-time polymerase chain reaction. In addition, N1 induced significant increases in HO-1 and Nrf2 expression, but inhibited phosphorylation of NF-κB in the HCFs treated with TGF-β1.

CONCLUSIONS

Our findings show for the first time that N1 exerts anti-fibrotic and anti-inflammatory effects through suppression of COX-2, Smad2, STAT3, iNOS and NF-κB expressions as well as upregulation of Nrf2 and HO-1 expressions, which suggests they are potential therapeutic targets in the treatment of corneal fibrosis.