Pharmacokinetic Studies of Sustained-Release Depot of Dexamethasone in Beagle Dogs

A hyaluronic acid-modified cyclodextrin self-assembly system for the delivery of β-carotene in the treatment of dry eye disease

Dry eye disease (DED) is a multifactorial ocular disease, the core mechanism of which is the tear film instability caused by ocular oxidative stress damage and inflammation. Although various pharmaceutical agents are available for DED treatment, their effectiveness is often limited by the eyes' unique biological barriers, and the long-term use of steroid hormones can lead to several adverse effects. This study reported a nano-supramolecular delivery system consisting of a polycyclodextrin (PCD), hyaluronic acid (HA) and the natural compound β-carotene (BC) for the DED treatment. Our findings indicate that the HA/PCD@BC eye drops effectively distribute on the ocular surface, retain BC, and significantly enhance the corneal penetration of BC. The excellent biocompatibility of HA/PCD@BC was demonstrated through viability testing on different cell lines, the Draize eye test, as well as the hematoxylin-eosin staining (H&E) sections of cornea and conjunctiva. Both in vitro oxidative stress assays and in vivo DED model evaluations demonstrated that the HA/PCD@BC delivery system significantly reduced abnormal oxidative stress levels on the ocular surface, inhibited the secretion of inflammatory factors, and increased the secretion of tear film stabilizing mucin. These effects collectively improved pathological changes in eye tissues and minimized damage to the ocular surface. It is of particular importance to note that HA/PCD@BC eye drops showed superior efficacy in comparison to cyclosporine A (CsA), an FDA-approved first-line drug. To sum up, the HA/PCD@BC nanodelivery system provides a natural, safe and effective therapeutic strategy for the treatment of DED and various ocular diseases.

Adopting Interventional Glaucoma Via Sustained-Release Therapies: The Wide-Ranging Impact of Procedural Pharmaceuticals in Ophthalmology

Topical medical therapy is the most common approach to the treatment of many ocular conditions. While effective, topical therapy has numerous important limitations. Eye drops can have unpleasant or even dangerous side effects, are often difficult to self-administer, and the application of multiple drops per day, possibly from multiple different bottles, can be burdensome. Perhaps the most important limitation of topical medical therapy is non-adherence, a complex multifactorial behavior that increases the risk of poor outcomes associated with undertreatment. There is growing interest in a class of therapeutics termed "procedural pharmaceuticals" (PPs), which remove the responsibility of self-dosing from patients. An array of PPs are available for the treatment of a variety of ocular conditions, such as those for glaucoma, retina, and cataract surgery; and many more will emerge in coming years. A paradigm shift away from patient-administered therapy toward provider-administered therapy will have important implications for both providers and patients. This paper explores the impact that PPs have had, and will have, on the clinical practice of ophthalmology.

A Randomized, Multicenter Phase 3 Clinical Trial Evaluating Intracanalicular Dexamethasone Insert for the Treatment of Allergic Conjunctivitis

Purpose

To evaluate the efficacy and safety of a dexamethasone intracanalicular insert (DEX) for treatment of allergic conjunctivitis (AC).

Patients and Methods

In this multicenter, randomized, double-masked, placebo-controlled phase 3 study, adults (≥18 years) with AC were randomized 1:1 to DEX or placebo insert (PBO) placed bilaterally. Subjects underwent repetitive conjunctival allergen challenges (CAC) across 30 days and were assessed for changes in AC signs and symptoms. The primary endpoint was ocular itching score at 3, 5, and 7 minutes post-CAC at Day 8 (7 days post-insertion). This trial is registered on ClinicalTrials.gov (NCT04050865).

Results

Ninety-six subjects were randomized (n=48 DEX, n=48 PBO). Compared to PBO, there were statistically significant treatment differences favoring DEX for the primary endpoint of mean ocular itching score at Day 8 (-0.86, -0.98, -0.96 at 3, 5, and 7 minutes post-CAC respectively; P<0.0001 for all). Treatment differences favored DEX for all 24 time points across 6 visits and were statistically significant (P<0.05) except for the first post-insertion (Day 7, 3 minutes). For the 18 time points at which conjunctival redness was assessed, DEX had lower scores than PBO (P<0.05 for all). The most common ocular adverse events (AEs) in DEX subjects were eye discharge and irritation. No serious AEs, elevated intraocular pressure, dacryocanaliculitis, or use of rescue medications were reported.

Conclusion

Results of this study support the potential use of dexamethasone insert as a physician-administered, preservative-free treatment for AC, with significant improvements in ocular itching and conjunctival redness compared with placebo. The dexamethasone insert was generally safe with a favorable safety profile.

Remote-controlled dexamethasone-duration on eye-surface with a micelle-magnetic nanoparticulate co-delivery system for dry eye disease

Dexamethasone (DEX) is used to treat ocular surface diseases. However, regulating DEX duration in tears while preventing its absorption into the anterior chamber is critical for balancing its therapy effects and the side effects. In this study, a novel magnetic nanoparticle (MNP)-micelle (MC) co-delivery system (MMDS) was developed. The MC moiety in the MMDS served as the carrier for DEX and the MNP part endowed the MMDS with magnetic-responsive properties. To extend its residency, the MMDS was magnetically attracted by an external magnet after instilling, which acted as a precorneal drug-depot enabling a sustainable release of DEX in tears. With combination of magnet treatment, the topical instillation of MMDS@DEX significantly prolonged the DEX-retention in tears and increased the DEX-concentration in the cornea and conjunctiva, as well as concurrently reduced the DEX-level in the aqueous humor, when compared with the commercial DEX eye drop treatment. The combination of MMDS@DEX and magnet treatment exerted significantly better therapeutic effects against DED with smaller side effects than conventional treatments including DEX suspension, commercial DEX eye drops, as well as the MMDS@DEX treatment alone. The present work provided a new method for the effective delivery of DEX to ocular surface tissues while reducing its side effects, which will be beneficial to the treatments of a wide range of ocular surface diseases.

DEXTENZA versus Topical Steroid or Antihistamine Therapy for Treatment of Allergic Conjunctivitis

Purpose

To compare clinical outcomes and patient preference for the dexamethasone intracanalicular insert (DEX) versus topical loteprednol (LOT) or olopatadine (OLO) for the treatment of allergic conjunctivitis in a real-world model of allergen exposure.

Methods

This was a prospective comparative trial. Adults with testing-confirmed bilateral allergic conjunctivitis received DEX in the more symptomatic eye and either LOT 2 times daily or OLO once daily for 30 days in the fellow eye. The primary outcome was patient preference for treatment. Clinical outcomes included ocular itching and hyperemia, lid swelling, and watering/tearing. Safety outcomes included intraocular pressure (IOP).

Results

Thirty patients participated and completed the study. All received DEX in the eye with worse symptoms and 15 received LOT and the other 15 received OLO in the other eye. Patients preferred DEX (10/15; 66.7%) over LOT (4/15; 26.7%), with one patient having no preference (p = 0.0103). Patients had no preference between DEX (8/15; 53.3%) and OLO (6/15; 40%), with one patient having no preference (p = 0.1044). In the DEX/LOT cohort, ocular itching and hyperemia improved more with DEX than LOT (p ≤ 0.009), while in the DEX/OLO cohort, the DEX eyes showed greater improvement in conjunctival hyperemia (p < 0.0001) but not itching (p = 0.074). No between-group differences were seen in eyelid swelling or tearing/watering in either cohort. Mean change in IOP was similar between the DEX and LOT eyes (p = 0.4921), and mean IOP rose more in the DEX eyes than the OLO eyes (by <1 mmHg; p = 0.0403).

Conclusion

Overall, this real-world study demonstrated that the dexamethasone intracanalicular insert was as effective as a topical antihistamine/mast cell stabilizer and more effective than topical steroids in relieving the signs and symptoms of allergic conjunctivitis. This insert should be considered as an alternative to topical therapy for the treatment of allergic conjunctivitis.

Management of inflammation after the cataract surgery

PURPOSE OF REVIEW

To review most recent studies and clinical trials regarding pathogenesis, treatment, and prevention of inflammation after the cataract surgery.

RECENT FINDINGS

FLACS gave opportunity to evaluate inflammatory cytokines in the aqueous humour right after the laser procedure, which led to acknowledging the inflammation pathogenesis during the phacoemulsification. Although there is still a lack of evidence, which would prove the long-term benefit of NSAIDs, they are indicated and effective when risk factors for PCME are present. PREMED studies showed that combination of NSAID and steroids after the surgery for healthy subjects is cost-effective. The triamcinolone injection together with topical steroids and NSAIDs for diabetic patients after the cataract surgery was the most cost-effective in preventing PCME according to the PREMED. Dropless cataract surgery is another emerging topic: dexamethasone implants and suspensions look promising as we await more clinical trials with drug-loaded IOLs.

SUMMARY

Inflammation after the cataract surgery can be prevented, and these methods are one of the most essential topics with growing phacoemulsification rate. Topical NSAIDs are cost-effective not only for patients with risk factors for PCME but also for healthy subjects. New dropless techniques are being successfully introduced in the clinical practice.

Subpalpebral lavage placement for remote topical administration of ocular medications in 12 dogs: A retrospective review and assessment of owner perception

OBJECTIVE

The aim of this study was to describe the placement of subpalpebral lavage (SPL) systems in 12 dogs (15 eyes) intolerant of topical ocular medications to assess the suitability, complications encountered and owner perception of use.

ANIMALS STUDIED

Retrospective review of dogs that underwent SPL placement for treatment of ocular disease at the Ophthalmology Department, University of Bristol Small Animal Hospital between 2017 and 2021.

PROCEDURE(S)

Data recorded included signalment, history, diagnosis, treatment, reason for SPL placement, uni- or bilateral placement, duration of placement, complications, and outcome. Owner perception was assessed using an online questionnaire. Statistical analysis included McNemar and Wilcoxon signed-ranks tests.

RESULTS

Twelve dogs (15 eyes) underwent SPL placement. Eleven owners completed the online questionnaire. Corneal ulceration was the most common disease requiring SPL placement (n = 13/15 eyes, 86.7%). Most cases received multimodal topical therapy (n = 9/15 eyes, 60.0%) via SPL. Owners administered medication 6.63 times daily via SPL (range 1-16 applications/day). All dogs requiring ongoing topical medication (n = 8/12, 66.7%) were trained to accept direct administration during SPL treatment. Statistically significant improvements in medication compliance, ease of application, and reduced perceived risk of iatrogenic ocular injury were reported by owners (p-value = .001, .004, and .031 respectively). Minor complications were infrequently reported but an excellent outcome was achieved for all eyes.

CONCLUSION

Subpalpebral lavage placement provides a practical and safe solution for the provision of frequent multimodal ocular medication when treating patients with a challenging temperament.

Long-acting formulation strategies for protein and peptide delivery in the treatment of PSED

The invigoration of protein and peptides in serious eye disease includes age-related macular degeneration, choroidal neovascularization, retinal neovascularization, and diabetic retinopathy. The transportation of macromolecules like aptamers, recombinant proteins, and monoclonal antibodies to the posterior segment of the eye is challenging due to their high molecular weight, rapid degradation, and low solubility. Moreover, it requires frequent administration for prolonged therapy. The long-acting novel formulation strategies are helpful to overcome these issues and provide superior therapy. It avoids frequent administration, improves stability, high retention time, and avoids burst release. This review briefly enlightens posterior segments of eye diseases with their diagnosis techniques and treatments. This article mainly focuses on recent advanced approaches like intravitreal implants and injectables, electrospun injectables, 3D printed drug-loaded implants, nanostructure thin-film polymer devices encapsulated cell technology-based intravitreal implants, injectable and depots, microneedles, PDS with ranibizumab, polymer nanoparticles, inorganic nanoparticles, hydrogels and microparticles for delivering macromolecules in the eye for intended therapy. Furthermore, novel techniques like aptamer, small Interference RNA, and stem cell therapy were also discussed. It is predicted that these systems will make revolutionary changes in treating posterior segment eye diseases in future.

Long-acting ocular drug delivery technologies with clinical precedent

INTRODUCTION

Ocular long-acting injectables and implants (LAIIs) deliver drug at a controlled release rate over weeks to years. A reduced dose frequency eases the treatment burden on patients, minimizes the potential for treatment-related adverse effects, and improves treatment adherence and persistence.

AREAS COVERED

This review provides a comprehensive landscape of ocular LAII drug delivery technologies with clinical precedent, including eight commercial products and 27 clinical programs. Analysis of this landscape, and the specific technologies with the greatest precedent, provides instructive lessons for researchers interested in this space and insights into the direction of the field.

EXPERT OPINION

Further technological advancement is required to create biodegradable LAIIs with extended release durations and LAIIs that are compatible with a broader array of therapeutic modalities. In the future, ocular LAII innovations can be applied to diseases with limited treatment options, prophylactic treatment at earlier stages of disease, and cost-effective treatment of ocular diseases in global health settings.

Thermal Pulsation with or without Dexamethasone Intracanalicular Insert for Meibomian Gland Dysfunction: A Prospective, Masked Trial

Significance

Meibomian gland dysfunction (MGD) is among the most common causes of dry eye disease worldwide. Few studies have compared treatment options, and the basis for an evidentiary approach to MGD management is lacking. We have conducted a non-randomized trial evaluating the additive benefit of a recently developed therapy.

Purpose

To compare the efficacy of thermal pulsation therapy alone or combined with the dexamethasone intracanalicular insert (Dextenza) on the signs and symptoms of MGD.

Methods

This was a prospective, patient-masked, sham-controlled, non-randomized trial. All subjects underwent thermal pulsation therapy using the LipiFlow system. The dexamethasone intracanalicular insert was placed in the inferior canaliculus of the more symptomatic eye (DEX group), while sham punctal dilation of the fellow eye was performed to preserve patient masking (SHAM group). Key outcomes were improvement in meibum expressibility at 1, 4, and 12 weeks and patient treatment preference at week 12.

Results

Nineteen subjects underwent thermal pulsation therapy and received the DEX insert. Meibomian gland expressibility scores improved significantly in both groups at 1, 4, and 12 weeks, with significantly greater improvement in DEX eyes than SHAM eyes at 12 weeks (P=0.027). Improvement from baseline in TBUT was significant at all time points in DEX eyes and only at week 4 in SHAM eyes, with significantly greater improvement in DEX eyes over SHAM eyes at week 12 (P=0.028). Mean best-corrected visual acuity and intraocular pressure remained unchanged from baseline throughout follow-up in both groups, and no adverse events were noted. Combined therapy with DEX was preferred by 61% of subjects.

Conclusion

This study demonstrated a significant benefit of combining thermal pulsation therapy with the dexamethasone intracanalicular insert on signs of MGD including TBUT and meibomian gland expressibility score. Consequently, a majority of patients preferred combination therapy to thermal pulsation therapy alone.

Liposomal drug delivery system for anti-inflammatory treatment after cataract surgery: a phase I/II clinical trial

Liposomes as a drug delivery system may overcome the problems associated with non-compliance to eyedrops and inadequate control of inflammation after cataract surgery. We evaluated the safety and efficacy of a single subconjunctival injection of liposomal prednisolone phosphate (LPP) for the treatment of post-cataract surgery inflammation. This is a phase I/II, open-label non-comparative interventional trial of patients undergoing cataract surgery. All patients received a single injection of subconjunctival LPP intraoperatively. The primary outcome measure was the proportion of eyes with an anterior chamber cell count of 0 at postoperative month 1. Ocular and non-ocular adverse events, including elevated intraocular pressure, rebound iritis and pseudophakic macular edema were monitored. Five patients were enrolled in this study. The mean age was 66.6 ± 6.2 and 4 (80%) were male. The proportion of patients with AC cell grading of 0 was 0%, 80%, 80%, and 100% at day 1, week 1, month 1, and month 2 after cataract surgery, respectively. Mean laser flare photometry readings were significantly elevated at week 1 after cataract surgery (48.8 ± 18.9, p = 0.03) compared with baseline, decreasing to 25.8 ± 9.2 (p = 0.04) at month 1 and returned to baseline by month 2 (10.9 ± 5.1, p = 1.0). No ocular or non-ocular adverse events were observed. Liposomal prednisolone phosphate, administered as a single subconjunctival injection intraoperatively, can be a safe and effective treatment for post-cataract surgery inflammation. The delivery of steroids with a liposomal drug delivery system could potentially replace eyedrops as anti-inflammatory therapy following cataract surgery.

Evaluation of Same-Day versus Next-Day Implantation of Intracanalicular Dexamethasone for the Control of Postoperative Inflammation and Pain Following Cataract Surgery

Purpose

To evaluate the safety and efficacy of a sustained-release intracanalicular dexamethasone insert for postoperative inflammation and pain implanted in a clinical setting preoperatively or on postoperative day 1.

Methods

Single-site, retrospective, contralateral eye study of patients undergoing cataract surgery. Included were subjects with a dexamethasone intracanalicular insert implanted in the clinic immediately prior to surgery in one eye (same-day) and on postoperative day 1 (POD1) in the contralateral eye. The primary outcome measure was the resolution of anterior chamber inflammation at 1 week postoperative. Secondary outcome measures included proportion of eyes requiring additional therapy for pain and inflammation through 1 month as well as the number of eyes with IOP spikes above baseline. Safety measures included adverse events through 1 month postoperative.

Results

Sixty-two eyes of 31 subjects were included in the case series. At 1 week postoperative, 52% of the eyes (n = 16) achieved complete resolution of inflammation in the same-day group and 58% (n = 18) met this endpoint at 1 week in the POD1 group. One subject in the same-day group required additional therapy for rebound inflammation and no eyes required additional therapy in the POD1 group. There were no reports of pain at 1 week or 1 month in either group. There were no implant-related adverse events in either group.

Conclusion

The favorable results of this study indicate that the sustained-release dexamethasone insert can be safely implanted in the clinic either preoperatively on the day of surgery or on postoperative day 1 for the control of pain and inflammation following cataract surgery.

Immunomodulatory biomaterials and their application in therapies for chronic inflammation-related diseases

The degree of tissue injuries such as the level of scarring or organ dysfunction, and the immune response against them primarily determine the outcome and speed of healing process. The successful regeneration of functional tissues requires proper modulation of inflammation-producing immune cells and bioactive factors existing in the damaged microenvironment. In the tissue repair and regeneration processes, different types of biomaterials are implanted either alone or by combined with other bioactive factors, which will interact with the immune systems including immune cells, cytokines and chemokines etc. to achieve different results highly depending on this interplay. In this review article, the influences of different types of biomaterials such as nanoparticles, hydrogels and scaffolds on the immune cells and the modification of immune-responsive factors such as reactive oxygen species (ROS), cytokines, chemokines, enzymes, and metalloproteinases in tissue microenvironment are summarized. In addition, the recent advances of immune-responsive biomaterials in therapy of inflammation-associated diseases such as myocardial infarction, spinal cord injury, osteoarthritis, inflammatory bowel disease and diabetic ulcer are discussed.

Review of Approaches for Increasing Ophthalmic Bioavailability for Eye Drop Formulations

Ophthalmic diseases represent a significant problem as over 2 billion people worldwide suffer from vison impairment and blindness. Eye drops account for around 90% of ophthalmic medications but are limited in success due to poor patient compliance and low bioavailability. Low bioavailability can be attributed to short retention times in the eye caused by rapid tear turnover and the difficulty of drug diffusion through the multi-layered structure of the eye that includes lipid-rich endothelial and epithelial layers as well as the stroma which is high in water content. In addition, there are barriers such as tight junctional complexes in the corneal epithelium, lacrimal turnover, nasolacrimal drainage, blinking reflexes, efflux transporters, drug metabolism by ocular enzymes, and drug binding to or repulsion from conjunctival mucins, tear proteins, and melanin. In order to maximize transport through the cornea while minimizing drug loss through other pathways, researchers have developed numerous methods to improve eye drop formulations including the addition of viscosity enhancers, permeability enhancers, mucoadhesives, and vasoconstrictors, or using formulations that include puncta occlusion, nanocarriers, or prodrugs. This review explains the mechanism behind each of these methods, examines their history, analyzes previous and current research, evaluates future applications, and discusses the pros and cons of each technique.

Dropless cataract surgery: modernizing perioperative medical therapy to improve outcomes and patient satisfaction

PURPOSE OF REVIEW

Advances in pharmacology offer freedom from topical medical therapy without compromise of anti-inflammatory and antimicrobial coverage in the perioperative period. In this review, we describe the basis for dropless cataract surgery with the goal of improving outcomes and the patient experience.

RECENT FINDINGS

Phacoemulsification outcomes depend largely on surgeon skill but also on adherence to a complex multidrug regimen of perioperative anti-inflammatory and antimicrobial therapy to prevent sight-threatening complications such as cystoid macular edema or endophthalmitis. Successful administration of this regimen can be limited by noncompliance, difficulty administering eye drops, bioavailability, and side effects, among others. The recent development of sustained-release formulations of dexamethasone - one an intracanalicular insert and the other an intraocular suspension - can provide sustained tapering doses of dexamethasone while reducing or eliminating the need for anti-inflammatory eye drop therapy. Similarly, mounting evidence compellingly demonstrates that intracameral antibiotic use intraoperatively is at least as effective as topical antibiotics in preventing endophthalmitis.

SUMMARY

Sustained-release dexamethasone coupled with intracameral antibiotics at the time of phacoemulsification can provide antimicrobial and anti-inflammatory prophylaxis without the need for topical eye drop medications. This approach has the potential to improve compliance with therapy, visual acuity outcomes, and the overall patient experience.

A review of the clinical applications of drug delivery systems for the treatment of ocular anterior segment inflammation

Ocular anterior segment inflammation is a medical problem that is seen in cases of cataract surgery and non-infectious anterior uveitis. Inadequately treated anterior segment inflammation can lead to sight-threatening conditions such as corneal oedema, glaucoma and cystoid macular oedema. The mainstay of treatment for anterior segment inflammation is topical steroid eye-drops. However, several drawbacks limit the critical value of this treatment, including low bioavailability, poor patient compliance, relatively difficult administration manner and risk of blurring of vision and ocular irritation. A drug delivery system (DDS) that can provide increased bioavailability and sustained delivery while being specifically targeted towards inflamed ocular tissue can potentially replace daily eye-drops as the gold standard for management of anterior segment inflammation. The various DDS for anti-inflammatory drugs for the treatment of anterior segment inflammation are listed and summarised in this review, with a focus on commercially available products and those in clinical trials. Dextenza, INVELTYS, Dexycu and Bromsite are examples of DDS that have enjoyed success in clinical trials leading to FDA approval. Nanoparticles and ocular iontophoresis form the next wave of DDS that have the potential to replace topical steroids eye-drops as the treatment of choice for anterior segment inflammation. With the current relentless pace of ophthalmic drug delivery research, the pursuit of a new standard of treatment that eliminates the problems of low bioavailability and patient compliance may soon be realised.

Dexamethasone Intracanalicular Insert: A Review in Treating Post-Surgical Ocular Pain and Inflammation

Dextenza®, an intracanalicular insert that is placed into the lower punctal opening of the eye, gradually releases dexamethasone for up to 30 days to alleviate pain and inflammation associated with ophthalmic surgery. A significantly higher proportion of patients treated with the dexamethasone intracanalicular insert than with the placebo insert had no pain at day 8 (co-primary endpoint, 7 days post-operation) across three pivotal phase III trials, and the inflammation co-primary endpoint (absence of anterior chamber cells) at day 14 (13 days post-operation) was met in two of three trials. Overall, the dexamethasone intracanalicular insert was effective and generally well tolerated for the treatment of post-surgical ocular pain and inflammation following cataract surgery. As low patient adherence is an issue for topical ophthalmic anti-inflammatory medications, the convenience (ease of insertion, single application with no patient input and typically no removal required) of the dexamethasone intracanalicular insert makes it a promising emerging option for the treatment of ocular inflammation and pain following ophthalmic surgery.

Nanocarriers for the Delivery of Medical, Veterinary, and Agricultural Active Ingredients

Nanocarrier-based delivery systems can be used to increase the safety and efficacy of active ingredients in medical, veterinary, or agricultural applications, particularly when such ingredients are unstable, sparingly soluble, or cause off-target effects. In this review, we highlight the diversity of nanocarrier materials and their key advantages compared to free active ingredients. We discuss current trends based on peer-reviewed research articles, patent applications, clinical trials, and the nanocarrier formulations already approved by regulatory bodies. Although most nanocarriers have been engineered to combat cancer, the number of formulations developed for other purposes is growing rapidly, especially those for the treatment of infectious diseases and parasites affecting humans, livestock, and companion animals. The regulation and prohibition of many pesticides have also fueled research to develop targeted pesticide delivery systems based on nanocarriers, which maximize efficacy while minimizing the environmental impact of agrochemicals.

Punctum and canalicular anatomy for hydrogel-based intracanalicular insert technology

Aim: Despite advances in cataract surgery, postoperative ocular inflammation and pain occurs. To address compliance issues with topical corticosteroid administration, a hydrogel-based dexamethasone insert was developed for intracanalicular administration. The objective is to understand the anatomy to best administer the insert and learn how the anatomy and hydrogel properties help retain the insert in the canaliculus over time. Materials & methods: Human cadavers (n = 5) were dissected to assess dimensions of punctum and canaliculus as part of drug discovery and development. Results & conclusions: Mean measures for punctal diameter was 0.5 ± 0 mm and vertical canaliculi length was 2.4 ± 0.5 mm and width was 1.6 ± 0.5 mm. Vertical canalicular width was larger than the punctal opening, a critical understanding for placing and retaining intracanalicular inserts.

Hydrogels and Their Applications in Targeted Drug Delivery

Conventional drug delivery approaches are plagued by issues pertaining to systemic toxicity and repeated dosing. Hydrogels offer convenient drug delivery vehicles to ensure these disadvantages are minimized and the therapeutic benefits from the drug are optimized. With exquisitely tunable physical properties that confer them great controlled drug release features and the merits they offer for labile drug protection from degradation, hydrogels emerge as very efficient drug delivery systems. The versatility and diversity of the hydrogels extend their applications beyond targeted drug delivery also to wound dressings, contact lenses and tissue engineering to name but a few. They are 90% water, and highly porous to accommodate drugs for delivery and facilitate controlled release. Herein we discuss hydrogels and how they could be manipulated for targeted drug delivery applications. Suitable examples from the literature are provided that support the recent advancements of hydrogels in targeted drug delivery in diverse disease areas and how they could be suitably modified in very different ways for achieving significant impact in targeted drug delivery. With their enormous amenability to modification, hydrogels serve as promising delivery vehicles of therapeutic molecules in several disease conditions, including cancer and diabetes.

Multicenter randomized phase 3 study of a sustained-release intracanalicular dexamethasone insert for treatment of ocular inflammation and pain after cataract surgery

PURPOSE

To assess the efficacy and safety of a sustained-release intracanalicular dexamethasone insert for the treatment of postoperative ocular inflammation and pain in patients having cataract surgery.

SETTING

Twenty-one United States sites.

DESIGN

Prospective multicenter randomized parallel-arm double-masked vehicle-controlled phase 3 study.

METHODS

Patients with planned clear corneal cataract surgery were randomized (1:1) to receive dexamethasone insert or placebo, and the treatment was placed in the canaliculus of the eye immediately after surgery (Day 1). The primary efficacy endpoints were complete absence of anterior chamber cells at Day 14 and complete absence of pain at Day 8.

RESULTS

The study comprised 438 adult patients (216 in the treatment arm and 222 in the placebo arm). At Day 14, significantly more patients had an absence of anterior chamber cells in the dexamethasone insert arm compared with placebo (52.3% versus 31.1%; P < .0001). At Day 8, significantly more patients had an absence of ocular pain in the dexamethasone insert arm compared with placebo (79.6% versus 61.3%; P < .0001). The dexamethasone insert arm showed no increase compared with placebo in incidence of all adverse events or ocular adverse events. Twice as many placebo patients required rescue therapy, compared with treated patients at Day 14.

CONCLUSIONS

Both primary endpoints were successfully met. In addition, patients receiving the dexamethasone insert experienced a decrease in inflammation after surgery as early as Day 4 through Day 45, and a decrease in pain as early as one day after surgery (Day 2) through Day 45. The dexamethasone insert was well-tolerated, and the adverse events profile was similar to placebo.

Intravitreal anti-VEGF agents, oral glucocorticoids, and laser photocoagulation combination therapy for macular edema secondary to retinal vein occlusion: preliminary report

AIM

To evaluate the efficacy and safety of combined anti-vascular endothelial growth factor (VEGF) agents, oral glucocorticoid, and laser photocoagulation therapy for macular edema (ME) secondary to retinal vein occlusion (RVO).

METHODS

This study included 16 eyes of 16 patients with RVO-associated ME. Patients were initially treated with oral prednisone and an intravitreal anti-VEGF agent. Two weeks later, patients underwent standard laser photocoagulation. Best-corrected visual acuity (BCVA), central retinal thickness (CRT), and retinal vessel oxygenation were examined over 12mo.

RESULTS

Patients received 1.43±0.81 anti-VEGF injections. Mean baseline and 12-month logMAR BCVA were 0.96±0.51 (20/178) and 0.31±0.88 (20/40), respectively, in eyes with central retinal vein occlusion (CRVO) (P<0.00), and 1.02±0.45 (20/209) and 0.60±0.49 (20/80), respectively, in eyes with branch retinal vein occlusion (BRVO) (P<0.00). At 12mo, CRT had significantly decreased in eyes with CRVO (P<0.00) and BRVO (P<0.00). Venous oxygen saturation had significantly increased in eyes with CRVO (P<0.00) and BRVO (P<0.00). No examined parameters were significantly different between the 2 RVO groups. No serious adverse effects occurred.

CONCLUSION

Anti-VEGF, glucocorticoid, and photocoagulation combination therapy improves visual outcome, prolongs therapeutic effect, and reduces the number of intravitreal injections in eyes with RVO-associated ME.

Ocular translational science: A review of development steps and paths

Developing successful drug delivery methods is challenging for any tissue, and the eye is no exception. Translating initial concepts into advanced technologies treating diseases in preclinical models and finally into functional and marketable products for humans can be particularly daunting. While referring to specific ophthalmic companies and products, this review considers key exchanges that lead to successful translation. By building on basic science discoveries in the academic setting, applied science can perform proof-of-concept work with simple, benchtop experiments. Eventually, simple models need to be translated to more robust ones where cells, tissues, and entire organisms are incorporated. Successful translation also includes performing due diligence of the intellectual property, understanding the market needs, undertaking clinical development, meeting regulatory requirements, and eventually scale up manufacturing. Different stages of the translation can occur in different environments, including moving from academia to industry, from one company to another, or between veterinary and human applications. The translation process may also rely on contract organizations to move through the complex landscape. While the path to a commercial, marketable product may not look the same each time, it is important to design a development plan with clear goals and milestones to keep on track.

Pharmaceutical technology can turn a traditional drug, dexamethasone into a first-line ocular medicine. A global perspective and future trends

Dexamethasone is one of the most prescribed glucocorticoids. It is effective and safe in the treatment of a wide variety of ocular conditions, including anterior and posterior segment inflammation. However, its half-life in the vitreous humor is very short, which means that it typically requires frequent administrations, thus reducing patient adherence and causing therapeutic failure. Innovative dexamethasone delivery systems have been designed in an attempt to achieve sustained release and targeting. The FDA has approved dexamethasone implants for the treatment of macular edema secondary to retinal vein occlusion and posterior segment noninfectious uveitis. Lenses, micro- and nanoparticles, liposomes, micelles and dendrimers are also proving to be adequate systems for maintaining optimal dexamethasone levels in the site of action. Pharmaceutical technology is turning a classical drug, dexamethasone, into a fashionable medicine.