The role of difluprednate ophthalmic emulsion in clinical practice

Selectfluor and alcohol-mediated synthesis of bicyclic oxyfluorination compounds by Wagner-Meerwein rearrangement

Herein, we report the first environmentally friendly systematic fluoroalkoxylation reactions in bicyclic systems. New oxyfluorination products were obtained with excellent yields (up to 98%) via Wagner-Meerwein rearrangement using benzonorbornadiene and the chiral natural compound (+)-camphene as bicyclic alkenes, selectfluor as an electrophilic fluorine source, and water and various alcohols as nucleophile sources. The structure of bicyclic oxy- and alkoxyfluorine compounds was determined by NMR and QTOF-MS analyses.

Diagnosis, Treatment, and Prevention of Noninfectious Acute Anterior Uveitis with or without Human Leukocyte Antigen B27 in Adults - Expert Consensus in Taiwan

BACKGROUND

Anterior uveitis is the most common anatomical type of uveitis. Patients with noninfectious anterior uveitis may develop various ocular complications and eventually visual impairment. Appropriately differentiating the etiologies can help clinicians to predict the outcome, arrange clinical follow-up, and decide the treatment or prevention strategy. Adequate treatment and effective prevention strategies can reduce the frequency of recurrence and the risk of developing complications. Human leukocyte antigen (HLA)-B27 is the most common positive finding in patients with noninfectious AAU in many countries including Taiwan.

PURPOSE

To report a consensus from experienced uveitis specialists and rheumatologists was made in Taiwan.

METHODS

A panel of nine ophthalmologists from nine different referral centers with expertise in the management of uveitis and an experienced rheumatologist was held on January 16, 2022. A comprehensive literature review was performed. Differential diagnoses for etiologies, general treatments, and prevention strategies were discussed. Each statement in the consensus was made only if more than 70% of the experts agreed.

RESULTS

A flow chart and seven statements regarding the differential diagnoses for etiologies, treatments and preventions, and co-management with rheumatologists were included in the consensus.

CONCLUSIONS

This article discusses the general diagnosis, treatment, and prevention of noninfectious acute anterior uveitis, with or without HLA-B27, in adults for general ophthalmologists to improve overall outcomes of these patients.

Multiphase Drug Distribution and Exchange in Oil-in-Water Nanoemulsion Revealed by High-Resolution 19F qNMR

An oil-in-water (o/w) nanoemulsion (NE), composed of oil globules, stabilized by a surfactant, and dispersed in an aqueous phase, is increasingly developed in complex drug formulation. Kinetically stable NEs are used to formulate hydrophobic drugs and typically provide higher dosage strengths and better content uniformity. However, little is known accurately about drug distribution in its multiphase solution, especially for the possible drug presence in the surfactant (s) phase, the interface layer between the dispersed oil (o) and the continuous water (w) phases. Here, high-resolution ¹⁹F quantitative NMR spectroscopy was applied directly and noninvasively on an o/w NE drug product containing difluprednate (DFPN). The well-resolved ¹⁹F peaks of DFPN depended on the shielding molecules in each phase, which revealed mass-balanced DFPN distribution in multiple phases of (w), (s), and (o) of NE globules at a quantity of 1.8 ± 0.1, 35 ± 2, and 59 ± 3% per labeled content, respectively. Furthermore, the dilution-dependent ¹⁹F peak line broadening and shift suggested a millisecond dynamic exchange between the NE and the less-noticed smaller but thermodynamically stable microemulsion (ME) globules in NE solution. The high-resolution NMR result revealed that the drug availability could be quickly achieved using an o/w NE formulation because of the drug multiphase distribution and the ME-assisted fast drug exchange among globules.

Localized alopecia and suppression of hypothalamic-pituitary-adrenal (HPA) axis in dogs following treatment with difluprednate 0.05% ophthalmic emulsion (Durezol®)

Background

Despite the common use of topical ophthalmic corticosteroids in dogs, detailed reports on systemic and dermatologic adverse effects are limited.

Results

Nine purpose-bred research Beagles were treated with difluprednate 0.05% ophthalmic emulsion in one or both eyes 2–3 times daily. Some difluprednate treated dogs developed mild to severe alopecia of the periocular region, face, and distal pinna (5/9). The median duration of treatment prior to onset of dermatologic signs for difluprednate treated dogs was 550 days (453–1160 days). Diagnostic testing included complete blood count (CBC) and serum biochemistry, adrenocorticotropic hormone (ACTH) stimulation testing combined with endogenous ACTH measurement, and skin biopsy. The CBC and chemistry were within normal limits for all dogs. There were varying degrees of suppression of the hypothalamic-pituitary-adrenocortical (HPA) axis with difluprednate treatment. Dogs with the most profound alopecic changes had less pronounced HPA axis suppression compared to dogs with no integumentary changes. Skin biopsies demonstrated follicular atrophy and follicular keratosis. When topical difluprednate was reduced to unilateral therapy, the hair regrew on the untreated side of the face. In addition to the affected research dogs, a 7-year old female spayed Chihuahua that was being treated as a clinical patient with long-term difluprednate 0.05% ophthalmic emulsion developed generalized hypotrichosis on the head and body and a potbellied appearance. ACTH stimulation testing revealed suppression of the HPA axis with a mild increase in serum alkaline phosphatase (ALP) activity and a urine specific gravity of 1.016. The combination of clinical signs and laboratory abnormalities was supportive of iatrogenic hyperadrenocorticism.

Conclusions

In dogs long-term use of difluprednate ophthalmic emulsion results in HPA axis suppression and in some cases iatrogenic hyperadrenocorticism. A novel pattern of localized alopecia is suspected to be related to dermal absorption and local action due to superior potency and penetration compared to other commonly utilized ophthalmic corticosteroids.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-021-03072-9.

Topical Difluprednate for Early Corneal Graft Rejection After Penetrating Keratoplasty

Purpose

To evaluate the safety and efficacy of topical difluprednate ophthalmic emulsion use for prophylaxis of corneal graft rejection in patients undergoing penetrating keratoplasty.

Methods

This study reviewed the charts of patients undergoing penetrating keratoplasty who were treated with difluprednate (DP) ophthalmic emulsion postoperatively. At each follow-up visit, patients were followed for signs of graft rejection, cataract development, and intraocular pressure rise in addition to routine ocular examination.

Results

The charts of 36 patients (38 eyes) who underwent penetrating keratoplasty (PKP) (27 eyes) and PKP triple (11 eyes) were reviewed. All eyes were followed up for at least 8 months postoperatively. Five grafts developed rejection and three grafts subsequently failed. Six eyes had an increase of IOP that required use of antiglaucoma drops. Three eyes were switched from difluprednate to prednisolone acetate (PA) after persistent rise of IOP failed to respond to antiglaucoma drops. None of these cases needed glaucoma surgery. Two patients developed cataract during the follow-up period (out of 12 phakic eyes).

Conclusion

Topical difluprednate is potentially effective and safe in preventing graft rejection after penetrating keratoplasty. Larger prospective clinical trials are warranted.

Asymmetric synthesis of 1,2-fluorohydrin: iridium catalyzed hydrogenation of fluorinated allylic alcohol

We have developed a simple protocol for the preparation of 1,2-fluorohydrin by asymmetric hydrogenation of fluorinated allylic alcohols using an efficient azabicyclo thiazole-phosphine iridium complex. The iridium-catalyzed asymmetric synthesis of chiral 1,2-fluorohydrin molecules was carried out at ambient temperature with operational simplicity, and scalability. This method was compatible with various aromatic, aliphatic, and heterocyclic fluorinated compounds as well as a variety of polyfluorinated compounds, providing the corresponding products in excellent yields and enantioselectivities.

Corticosteroids in ophthalmology: drug delivery innovations, pharmacology, clinical applications, and future perspectives

Corticosteroids remain the mainstay of the treatment for various ocular conditions affecting the ocular surface, anterior and posterior segments of the eye due to their anti-inflammatory, anti-oedematous, and anti-neovascularization properties. Prednisolone, prednisolone acetate, dexamethasone, triamcinolone acetonide, fluocinolone acetonide, and loteprednol etabonate are amongst the most widely used ophthalmic corticosteroids. Corticosteroids differ in their activity and potency in the eye due to their inherent pharmacological and pharmaceutical differences. Different routes and regimens are available for ocular administration of corticosteroids. Conventional topical application to the eye is the route of choice when targeting diseases affecting the ocular surface and anterior segment, while periocular, intravitreal, and suprachoroidal injections can be potentially effective for posterior segment diseases. Corticosteroid-induced intraocular pressure elevation and cataract formation remain the most significant local risks following topical as well as systemic corticosteroid administration. Invasive drug administration via intracameral, subconjunctival, and intravitreal injection can enhance ocular bioavailability and minimize dose and dosing frequency of administration, yet may exacerbate ocular side effects of corticosteroids. This review provides a critical appraisal of the ophthalmic uses of corticosteroid, routes of administration, drug delivery fundamentals and novel ocular implantable steroid delivery systems, factors influencing side effects, and future perspectives for ocular corticosteroid therapy.

Literature review and suggested protocol for prevention and treatment of corneal graft rejection

Effective prophylaxis and treatment of corneal graft rejection are essential to improve outcomes in corneal transplantation. To date, there has been no standardized protocol published that outlines the optimal prophylactic and therapeutic approaches and, furthermore, the published controlled trials on this subject are limited. Likewise, no study has addressed how the level of antigen exposure varies between different types of keratoplasties. The aim of this paper is to provide a simple evidence-based protocol for the prevention and treatment of corneal graft rejection.

Metal-Free and User-Friendly Regioselective Hydroxyfluorination of Olefins

A simple, user-friendly, metal-free protocol for the regioselective anti-Markovnikov hydrofluorination of olefins using readily available and inexpensive reagents has been developed. This new approach displays a broader scope than previously reported methodologies and has been applied to the late-stage fluorination of a complex molecule, giving rise to a fluorosteroid derivative. The stereochemistry of the process has also been studied in some detail.

Modern Approaches for Asymmetric Construction of Carbon-Fluorine Quaternary Stereogenic Centers: Synthetic Challenges and Pharmaceutical Needs

New methods for preparation of tailor-made fluorine-containing compounds are in extremely high demand in nearly every sector of chemical industry. The asymmetric construction of quaternary C-F stereogenic centers is the most synthetically challenging and, consequently, the least developed area of research. As a reflection of this apparent methodological deficit, pharmaceutical drugs featuring C-F stereogenic centers constitute less than 1% of all fluorine-containing medicines currently on the market or in clinical development. Here we provide a comprehensive review of current research activity in this area, including such general directions as asymmetric electrophilic fluorination via organocatalytic and transition-metal catalyzed reactions, asymmetric elaboration of fluorine-containing substrates via alkylations, Mannich, Michael, and aldol additions, cross-coupling reactions, and biocatalytic approaches.

Bioavailability of generic 0.05% difluprednate emulsion in the aqueous humor, cornea, and conjunctiva of New Zealand rabbits after a single dose compared with commercial difluprednate

BACKGROUND

To determine the concentration after a single dose of generic 0.05% difluprednate and commercial difluprednate in the aqueous humor, cornea, and conjunctiva of New Zealand rabbits, a preclinical study in 72 male New Zealand white rabbits was performed. A single dose (50 μL) of two 0.05% difluprednate ophthalmic formulations was instilled in both eyes. Conjunctiva, cornea, and aqueous humor samples were collected at nine time points over 8 h (four animals per time point). The active metabolite of difluprednate, 17-difluoroprednisolone-butyrate (DFB), concentrations was quantified using HPLC.

RESULTS

Measurable levels of DFB were quantified in all three ocular tissues. After a single instillation, the highest concentration of difluprednate was found between 30 and 60 min in the conjunctiva, cornea, and aqueous humor, respectively. There was no significant difference between both formulations in any tissue at any time point. After 3 h, no metabolites of either emulsion were found in any tissue.

CONCLUSIONS

Difluprednate penetrates into different ocular tissues. Generic difluprednate has a similar pharmacokinetic profile compared with commercial difluprednate.

Management of high-risk corneal transplantation

The cornea is the most commonly transplanted tissue in medicine. The main cause of corneal graft failure is allograft rejection. The incidence of graft rejection depends on the presence of high-risk characteristics, most notably corneal neovascularization. Although corneal grafting has high success rates in the absence of these risk factors, high-risk keratoplasty is associated with low success rates because of a high incidence of immune-mediated graft rejection. To improve the survival of high-risk corneal transplantation, various preoperative, intraoperative, and postoperative measures can be considered; however, the key step in the management of these grafts is the long-term use of local and/or systemic immunosuppressive agents. Although a number of immunosuppressive agents have been used for this purpose, the results vary significantly across different studies. This is partly due to the lack of an optimized method for their use, as well as the lack of a precise stratification of the degree of risk in each individual patient. New targeted biologic treatments, as well as tolerance-inducing methods, show promising horizons in the management of high-risk corneal transplantation in near future.

To Study the Efficacy of Difluprednate Ophthalmic Emulsion and Prednisolone Acetate Ophthalmic Suspension on Post-operative Inflammation in Cataract Surgery

INTRODUCTION

Senile cataract is the most common cause of visual impairment. Removal of cataract and implantation of intraocular lens implantation (IOL) is the main surgical approach for cataract. The major block in quick visual rehabilitation of the patient is post-operative inflammation. To limit post-operative inflammation corticosteroids drugs are used in routine prophylactically. Topical prednisolone acetate 1% and betamethasone 0.1% remain gold standard to control post-operative inflammation but newer drugs like difluprednate, loteprednol are also effective in controlling inflammation.

AIM

To study the efficacy of difluprednate ophthalmic emulsion and prednisolone acetate ophthalmic suspension on Post-operative inflammation in cataract surgery (clear corneal phacoemulsification with foldable IOL).

MATERIALS AND METHODS

This study was carried out on 100 patients having visually significant cataract requiring surgery, clear corneal phacoemulsification with foldable intraocular lens implantation was done in all patients. Patients were randomly divided into two groups. In group A topical 1% prednisolone acetate ophthalmic suspension was administered six times a day Post-operatively. In group B 0.05% difluprednate ophthalmic emulsion was administered six times a day post-operatively. Efficacy of drug was evaluated in terms of decrease in ocular pain, anterior chamber reaction in the form of aqueous cells and flare and final visual acuity at 4 weeks.

RESULTS

In this study, 92% of patients in group A and 90% of patients in group B had BCVA 6/6. None of the patients in group A had ocular pain. In group B, 96% patients had no ocular pain. Remaining 4% had mild discomfort but required no medication. 98% of patients in group A and 100% of patients in group B presented with clearance of aqueous cells at the end of study. Only 2% of patients in group A had showed cell score (±).

CONCLUSION

Though prednisolone acetate has been the gold standard anti inflammatory agent, 0.05% Difluprednate ophthalmic emulsion is equally effective in treatment of post-operative inflammation. Difluprednate have added an advantage of uniform drug dosage and absence of harmful preservative.

A retrospective analysis of intraocular pressure changes after cataract surgery with the use of prednisolone acetate 1% versus difluprednate 0.05%

Purpose

To compare the effect of topical prednisolone acetate 1% (PA) used after routine cataract surgery to the effect of difluprednate 0.05% (DFBA) used for the same indication on intraocular pressure (IOP).

Methods

An electronic query was created to gather information from all cataract surgeries between January 2010 and January 2015 within the electronic health record database at Barnet Dulaney Perkins, a multicenter, multiphysician private practice in Phoenix, Arizona. Information collected included age, sex, diabetes status, glaucoma history, medication regimen (use of PA or DFBA), and IOP before surgery, 5–10 days postoperatively (TP1) and 3–6 weeks postoperatively (TP2). Postoperative IOP measurements were compared to baseline IOP measurement in each patient.

Results

Regardless of steroid used, all patients in this study experienced an increase in IOP within TP1 and returned to baseline IOP (±2.0 mmHg) by TP2. Patients who received DFBA showed a statistically significant increase in IOP at TP1 compared to those on PA (P<0.001) with the mean IOP an average 0.60 mmHg higher (95% CI =0.3, 0.9). The odds ratio of a clinically significantly increased IOP at TP1 (defined as overall IOP ≥21 mmHg and an increase of ≥10 mmHg) in DFBA-treated patients was 1.84 (95% CI =1.4, 2.6). In patients treated with PA, 3% reached a significantly increased IOP, compared to 4.4% of patients in the DFBA group (P<0.05). Risk factors for increased IOP were identified, and include advanced age (>75) (P<0.005) and a history of glaucoma (P<0.001).

Conclusion

In postoperative cataract patients, use of DFBA increased the risk of a clinically significant IOP increase.

Strong topical steroid, NSAID, and carbonic anhydrase inhibitor cocktail for treatment of cystoid macular edema

Purpose

To report the combination cocktail of strong steroid, non-steroidal anti-inflammatory drug (NSAID), and carbonic anhydrase inhibitor drops for treatment of cystoid macular edema.

Methods

This is a retrospective case series of patients with cystoid macular edema managed with a topical combination of strong steroid (difluprednate), NSAID, and carbonic anhydrase inhibitor drops. The patients were followed with optical coherence tomography and fluorescein angiography.

Results

In our six cases, resolution of the cystic edema with improvement in visual acuity was achieved with the use of a combination cocktail of drops. Leakage on fluorescein angiography and cystic edema on optical coherence tomography both responded to treatment with the topical cocktail of drops.

Conclusion

A topical cocktail of strong steroid, NSAID, and carbonic anhydrase inhibitor drops are effective for managing cystoid macular edema. Further studies comparing this combination with more invasive treatments should be undertaken to determine the efficacy of this cocktail over other treatment options.

Topical difluprednate for the treatment of Harada's disease

Purpose

To describe the use of topical difluprednate for treatment of patients who presented with Harada’s disease.

Methods

Retrospective case series of patients managed with topical difluprednate alone at the onset of the diagnosis. The patients were followed with optical coherence tomography (OCT) and fluorescein angiography.

Results

In our three cases, complete resolution of the exudative detachments with improvement in visual acuity was achieved in each case. Central macular thickness was reduced by a mean of 365±222 μm. Initial loading dose was one drop every hour while awake, followed by a variable tapering regimen. Leakage on fluorescein angiography and exudative detachments on OCT both responded to treatment with difluprednate. In two of the three cases, the patients recovered vision to 20/20, and the third case recovered to 20/25. Steroid-induced glaucoma was observed and managed with one to two glaucoma drops as needed.

Conclusion

Difluprednate is effective for managing ocular manifestations of Harada’s disease. Further studies of this drug for the management of noninfectious posterior uveitis are warranted.

Dose uniformity of topical corticosteroid preparations: difluprednate ophthalmic emulsion 0.05% versus branded and generic prednisolone acetate ophthalmic suspension 1%

Purpose

To compare the dose uniformity of difluprednate ophthalmic emulsion 0.05% (Durezol^®) with both branded and generic prednisolone acetate ophthalmic suspension 1% under different simulated patient usage conditions.

Methods

Drug concentrations of difluprednate emulsion, branded prednisolone acetate suspension (Pred Forte^®) and generic prednisolone acetate suspension following three storage conditions (upright, then shaken; upright, not shaken; inverted, not shaken) were analyzed by high performance liquid chromatography assay and results were reported as percent of declared concentration. Two drops were dispensed every four hours four times daily.

Results

Regardless of bottle orientation and shaking, all difluprednate emulsion concentrations at each time point analyzed were within 15% of declared concentration. Both branded and generic prednisolone acetate suspension concentrations varied substantially throughout the study. For the bottle stored upright and not shaken, 46% of the branded concentrations were not within 15% of declared concentration; for the bottle stored upright and shaken prior to use, 60% failed to meet this criterion. None of the branded concentrations from the inverted and not shaken bottle was within 15% of declared concentration. Generic prednisolone concentrations demonstrated the poorest dose uniformity, with 96% of the concentrations from the inverted and not shaken bottle not within 15% of declared concentration; 94% of the concentrations from the upright and shaken bottle and 87% from the upright and not shaken bottle similarly failed to meet this criterion.

Conclusions

Dose uniformity of Durezol emulsion was predictable in all simulated patient usage conditions, whereas the drop concentrations of Pred Forte and generic prednisolone acetate suspensions were highly variable throughout the study. Drop concentrations are more predictable with Durezol emulsion than with either prednisolone acetate suspension.