A randomized comparison of to-aqueous penetration of ketorolac 0.45%, bromfenac 0.09% and nepafenac 0.1% in cataract patients undergoing phacoemulsification

Pharmacokinetics and efficacy of a ketorolac-loaded ocular coil in New Zealand white rabbits

Eye drops are considered standard practice for the delivery of ocular drugs. However, low patient compliance and low drug levels compromise its effectiveness. Our group developed a ketorolac-loaded ocular coil for sustained drug delivery up to 28 days. The aim of this study was to gain insight into the pharmacokinetics and efficacy of the ocular coil. The pharmacokinetics of the ketorolac-loaded ocular coil versus eye drops were tested in New Zealand White rabbits by repetitive sampling for 28 days. Efficacy of the ocular coil was also tested in New Zealand White rabbits. Ocular inflammation was induced where after the ocular coil was inserted, or eye drops, or no treatment was provided. The total protein concentration and cytokine levels were measured in tears, aqueous humor, and plasma at 4 h, 8 h, 24 h, 4 d, 7 d, 14 d, 21 d, and 28 d. Four h after inserting the ocular coil in the eye, ketorolac levels in aqueous humor and plasma were higher in the ocular coil group than in the eye drop group. Ketorolac released from the ocular coil could be detected up to 28 d in tears, up to 4 d in aqueous humor and up to 24 h in plasma. After inducing inflammation, both the ocular coil and eye drops were able to suppress prostaglandin E₂, TNFα and IL-6 levels in aqueous humor and plasma as compared to the group that received no treatment. To conclude, the ocular coil facilitated a sustained release of the drug and showed similar therapeutic benefit in suppressing post-operative inflammation as eye drops.

Single subconjunctival injection formulation using sol-gel mesoporous silica as a controlled release system for drop-free post-cataract surgery care

PURPOSE

To develop a mesoporous silica drug delivery system and target drop-free care after cataract surgery with a single subconjunctival injection.

SETTING

Laboratory.

DESIGN

Experimental animal study.

METHODS

Ketorolac was infiltration-loaded into sol-gel mesoporous silica particles encapsulated with poly(allylamine hydrochloride) and poly(sodium 4-styrenesulfonate) using a layer-by-layer adsorption technique (SG-Ket-LBL). The formulation was subjected to an in vitro and in vivo drug release study in addition to ocular toxicology evaluation.

RESULTS

Thermogravimetric analysis revealed that the drug loading efficiency was 4.4% for the SG-Ket-LBL particles. The in vivo safety study demonstrated that the formulation was well tolerated after subconjunctival injection and aqueous humor pharmacokinetics showed sustained therapeutic drug release for the targeted time window of 6 to 8 weeks.

CONCLUSIONS

Findings indicated that sol-gel mesoporous silica could be used as a drug carrier for subconjunctival administration. The tested formulation, SG-Ket-LBL, provided therapeutic ketorolac for 6 to 8 weeks, which might be used for a single subconjunctival injection to replace nonsteroidal anti-inflammatory drug eyedrops after cataract surgery.

Effects of Pranoprofen on Aqueous Humor Monocyte Chemoattractant Protein-1 Level and Pain Relief During Second-Eye Cataract Surgery

The aim of our present study is to evaluate the efficacy of pranoprofen eye drops as pain relief during sequential second-eye cataract surgery and to investigate the possible mechanism. Seventy-six patients scheduled for bilateral sequential cataract surgery were randomly assigned to two groups: (1) treatment group (administered pranoprofen eye drops), or (2) control group (administered artificial tears). Preoperative anxiety and intraoperative pain were assessed. Monocyte chemoattractant protein 1 (MCP-1) in the aqueous humor was measured with a suspension cytokine array. An extracapsular lens extraction model was established in the Wistar rat and the MCP-1 concentrations were measured with an enzyme-linked immunosorbent assay. We found that in the control group, the pain scores were significantly higher during second-eye surgery than during first-eye surgery (both scores P < 0.001). In the treatment group, there was no significant difference in the pain scores during first-eye and second-eye surgery (both scores P > 0.1). The pain during second-eye surgery was significantly lower in the treatment group than in the control group (both scores P < 0.01). And in the 1-week and 6-week interval subgroups, the pain scores during second-eye surgery were significantly lower in the treatment group than the control group (P = 0.047 and P = 0.035, respectively). While the second-eye MCP-1 level was significantly lower after a 1-week interval in the treatment group than in the control group (P = 0.012), but did not differ significantly after a 6-week interval (P > 0.1). A parallel trend in the MCP-1 concentration was detected in the rat model. In conclusion, the preoperative administration of pranoprofen eye drops reduced the perceived pain during second-eye cataract surgery, especially when performed after 1-week and 6-week intervals between the first-eye and second-eye surgery. MCP-1, a pain-related cytokine, was associated with the pain-relief mechanism of pranoprofen when second-eye surgery was performed 1 week after second-eye surgery.

Alternative Drug Delivery for Patients Undergoing Cataract Surgery as Demonstrated in a Canine Model

PURPOSE

(1) To determine ketorolac concentrations in selected ocular tissues following the intracameral administration of phenylephrine and ketorolac injection 1%/0.3% (OMIDRIA^®) delivered in irrigation solution during lens replacement surgery in beagle dogs. (2) To compare the ketorolac initial dose and resultant concentrations from the above study to those achieved in aqueous and vitreous by topical administration in patients undergoing cataract surgery or vitrectomy, respectively.

METHODS

Lens replacement surgery with phacoemulsification was performed in 20 female beagle dogs. A fixed combination of phenylephrine and ketorolac injection 1%/0.3% was diluted 125-fold into the balanced salt solution and delivered intracamerally during the phacoemulsification procedure. Ketorolac concentration was determined by liquid chromatography/mass spectrometry.

RESULTS

Concentrations of ketorolac when administered by the intracameral route in the dosing solution in dogs were found to be considerably higher in both aqueous and vitreous compared to what is achieved with topical dosing in patients.

CONCLUSIONS

Adequate therapeutic concentrations of ketorolac in aqueous and vitreous humor were achieved even at 10 h postdose. Critical concentrations in the aqueous that envelopes the iris/ciliary body, which are sites of prostaglandin E₂ synthesis, and the vitreous are not achieved by topical dosing in clinical studies after the surgery, but are by direct intracameral dosing as determined in this study. Based on these studies and clinical data, phenylephrine and ketorolac injection 1%/0.3% delivered during surgery as an irrigation solution may preclude the need for topically administered pre- and postoperative NSAIDs.

Comparison of the efficacy and patients' tolerability of Nepafenac and Ketorolac in the treatment of ocular inflammation following cataract surgery: A meta-analysis of randomized controlled trials

As a new ophthalmic non-steroidal anti-inflammatory drug (NSAID) with prodrug structure, Nepafenac was supposed to have a better efficacy than conventional NSAIDs both in patients’ tolerability and ocular inflammation associated with cataract surgery. However, many current studies reached contradictory conclusions on the superiority of Nepafenac over Ketorolac. The objective of our study is to evaluate the efficacy and patients’ tolerability of Nepafenac and Ketorolac following cataract surgery. To clarify this, we conducted a meta-analysis of randomized controlled trials. Eleven articles were included in this study. The dataset consisted of 1165 patients, including 1175 cataract surgeries. Among them, 574 patients were in the Nepafenac group and 591 in the Ketorolac group. Our analysis indicated that these two drugs were equally effective in controlling post cataract surgery ocular inflammation, reducing macular edema, achieving a better visual ability and maintaining intraoperative mydriasis during cataract surgery. However, Nepafenac was more effective than Ketorolac in reducing the incidence of postoperative conjunctival hyperemia and ocular discomfort. This meta-analysis indicated that topical Nepafenac is superior to Ketorolac in patients’ tolerability following cataract surgery. However, these two drugs are equally desirable in the management of anterior chamber inflammation, visual rehabilitation and intraoperative mydriasis. Given the limitations in our study, more researches with larger sample sizes and focused on more specific indicators such as peak aqueous concentrations of drugs or PEG2 levels are required to reach a firmer conclusion.

Bromfenac 0.09% bioavailability in aqueous humor, prophylactic effect on cystoid macular edema, and clinical signs of ocular inflammation after phacoemulsification in a Mexican population

PURPOSE

The purpose of this study was to evaluate the aqueous humor bioavailability and clinical efficacy of bromfenac 0.09% vs nepafenac on the presence of cystoid macular edema (CME) after phacoemulsification.

MATERIAL AND METHODS

A Phase II, double-blind, masked, active-controlled, multicenter, clinical trial of 139 subjects, randomized to either a bromfenac 0.09% ophthalmic solution (n=69) or nepafenac 0.1% (n=70). Subjects instilled a drop three times a day for a period of 30 days. Follow-up visits were on days 2, 7, 15, 30, and 60. Biomicroscopy, clinical ocular signs, and assessment of posterior segment were performed. The primary efficacy endpoints included the presence of CME evaluated by optical coherence tomography. Safety evaluation included intraocular pressure, transaminase enzymes, lissamine green, and fluorescein stain.

RESULTS

The demographic and efficacy variables were similar between groups at baseline. The presence of pain, photophobia, conjunctival hyperemia, chemosis, cellularity, and corneal edema disappeared by day 30 in both groups. The central retinal thickness did not show significant changes after treatment when compared to baseline as follows: in the bromfenac group (247.2±32.9 vs 252.0±24.9 μm; P=0.958) and in nepafenac group (250.8±34 vs 264.0±34.1 μm; P=0.137), respectively. A statistically significant difference was observed between bromfenac and nepafenac group: (252.0±24.9 vs 264.0±34.1 μm; P=0.022), at day 30, respectively; even though there was no clinical relevance in the presentation of CME. There were no significant alterations in intraocular pressure, either lissamine green or fluorescein stains. The adverse events were not related to the interventions.

CONCLUSION

Bromfenac 0.09% ophthalmic solution showed similar clinical efficacy to reduce the presentation of CME after phacoemulsification compared to nepafenac 0.01%.

Prostaglandin E2 Levels of Aqueous and Vitreous Humor in Ketorolac 0.4% and Nepafenac 0.1% Administered Healthy Rabbits

PURPOSE

To compare the lowering effects of ketorolac 0.4% and nepafenac 0.1% on aqueous and vitreous humor prostaglandin E₂ (PGE₂) levels in rabbits.

METHODS

Ketorolac and nepafenac ophthalmic solutions were administered to the right eyes of 24 healthy rabbits after randomized division into two groups. The left eyes of these rabbits were considered as controls for the two groups. On the 4th day of the experiment, the samples were taken from the aqueous and vitreous humors of the rabbits bilaterally, and PGE₂ levels were measured by an enzyme immune assay kit.

RESULTS

Ketorolac and nepafenac achieved a statistically significant decrease (p<0.001, for each) in PGE₂ levels in the aqueous (11.75 ± 6.15 and 14.75 ± 7.60 pg/mL, respectively) and the vitreous humor (6.58 ± 4.62 and 9.83 ± 4.55 pg/mL, respectively).

CONCLUSIONS

Both ketorolac and nepafenac inhibited PGE₂ levels in both the aqueous and vitreous humors of rabbits. Although PGE₂-lowering effects were similar in the aqueous humor, nepafenac seemed to be more potent than ketorolac in the vitreous humor.

Efficacy and vitreous levels of topical NSAIDs

INTRODUCTION

Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications and are routinely used for their analgesic, antipyretic, and anti-inflammatory properties. Because of their potent cyclooxygenase-inhibitory activity, they can inhibit pro-inflammatory prostaglandin synthesis, leading to complex inflammatory cascades. NSAIDs have been broadly used systemically for many decades and have recently become commercially available in the form of topical ophthalmic formulations. NSAIDs are weak acids with pKa values mostly between 3.5 and 4.5 and are poorly water-soluble. New, aqueous ophthalmic solutions of NSAIDs that afford better tissue penetration have recently been developed. In ophthalmological practice, topical NSAIDs are mostly used to stabilize pupillary dilation during intraocular surgery, manage postoperative pain and inflammation, and treat pseudophakic cystoid macular edema.

AREAS COVERED

This review focuses on the vitreous penetration of topical NSAIDs and their potential clinical applications in the treatment of retinal diseases.

EXPERT OPINION

A growing body of evidence suggests that NSAIDs may be beneficial in the treatment of age-related macular degeneration, diabetic retinopathy, and ocular tumors. Recent studies from our group and other authors have shown that the vitreous levels of NSAID exceed the median inhibitory concentration, which can significantly decrease vitreous PGE2 levels.

Topical nonsteroidal anti-inflammatory drugs for macular edema

Nonsteroidal anti-inflammatory drugs (NSAIDs) are nowadays widely used in ophthalmology to reduce eye inflammation, pain, and cystoid macular edema associated with cataract surgery. Recently, new topical NSAIDs have been approved for topical ophthalmic use, allowing for greater drug penetration into the vitreous. Hence, new therapeutic effects can be achieved, such as reduction of exudation secondary to age-related macular degeneration or diabetic maculopathy. We provide an updated review on the clinical use of NSAIDs for retinal diseases, with a focus on the potential future applications.

Prophylactic postoperative ketorolac improves outcomes in diabetic patients assigned for cataract surgery

Objective

To evaluate the prophylactic role of topical non-steroidal anti-inflammatory drugs in reducing the incidence of central macular edema (CME) in diabetic eyes post-cataract surgery.

Patients and methods

This study included 86 eyes (70 patients) with high risk characteristics for the development of CME after cataract surgery. All patients underwent phacoemulsification and intraocular lens implantation. Patients were divided into two equal groups (n = 43 [eyes]): a control group given topical dexamethasone 0.1%, four times/day for 12 weeks postoperatively and a study group given topical ketorolac tromethamine 0.4% twice daily in addition to topical dexamethasone 0.1% four times daily for 12 weeks. Patients were examined at 3, 6, and 12 weeks postoperatively for evaluation of CME development. The main study outcome was the change in the retinal fovea thickness measured with ocular coherence topography.

Results

Ten eyes developed CME (11.6%); eight eyes in the control group and only two eyes in the study group. Mean retinal fovea thickness was significantly higher in the control group compared to the study group. Moreover, eyes of the control group developed CME significantly earlier than those of the study group.

Conclusion

Prophylactic postoperative ketorolac 0.4% may have a role in reducing the frequency and severity of CME in diabetic eyes post-cataract surgery.

Nepafenac: An Ophthalmic Nonsteroidal Antiinflammatory Drug for Pain After Cataract Surgery

OBJECTIVE:

To examine the efficacy of nepafenac in the treatment of pain and inflammation in patients after cataract surgery using evidence from controlled clinical studies.

DATA SOURCES:

Citations in Google Scholar, PubMed, and Web of Science from January 1, 2005, to March 25, 2013, were identified using nepafenac and cataract as search terms.

STUDY SELECTION AND DATA EXTRACTION:

The literature search was limited to human studies published in English. Three trials that compared nepafenac with other nonsteroidal antiinflammatory drugs (NSAIDs) were included.

DATA SYNTHESIS:

The pharmacokinetics and pharmacodynamics of nepafenac 0.1% suspension (and its active metabolite, amfenac) were compared with bromfenac 0.09% solution and ketorolac 0.4% solution with respect to aqueous humor concentrations and ability to reduce cyclooxygenase 1 and 2 (COX-1 and COX-2) enzymes. The maximum concentration (Cmax) values of ketorolac and amfenac were statistically similar, while the Cmax of bromfenac was significantly lower than that of amfenac. Ketorolac most effectively inhibited COX-1 enzymes; COX-2 enzymes were most effectively reduced by amfenac. When nepafenac 0.1% suspension was compared with placebo and ketorolac 0.5% solution, nepafenac achieved a higher percentage cure rate than placebo at day 14 (p = 0.0241). Significant differences in cure rates between nepafenac and ketorolac were not observed. Nepafenac 0.1%, bromfenac 0.09%, and ketorolac 0.45% were compared to determine which most effectively reduced prostaglandin E2 (PGE2) following surgery. PGE2 concentrations were significantly lowest in the ketorolac group, followed by the bromfenac and nepafenac groups, respectively. Topical nepafenac 0.1% suspension was approved in 2005. A 0.3% suspension was approved in October 2012. The 0.3% product may have some advantages over its predecessor: it is dosed once rather than thrice daily, which may increase patient adherence and improve outcomes. The price and dosing frequency of the 0.3% product are comparable to those of bromfenac 0.09% solution.

CONCLUSIONS:

The 2 nepafenac products appear to be equally efficacious, with a slightly increased adverse event rate in patients using the 0.3% versus 0.1% formulation. Head-to-head clinical trials that compare the 0.3% product with the 0.1% product or other commercially available NSAIDs are unavailable.