Comparative study of the analgesic efficacy of flurbiprofen and diclofenac in patients following excimer laser photorefractive keratectomy

Discovery of (S)-flurbiprofen-based novel azine derivatives as prostaglandin endoperoxide synthase-II inhibitors: Synthesis, in-vivo analgesic, anti-inflammatory activities, and their molecular docking

The anti-inflammatory and analgesic drugs currently used are associated with several adverse effects and found to be highly unsafe for long-term use. Currently, nineteen novel bis-Schiff base derivatives (1-19) of flurbiprofen have been designed, prepared and assessed for in-vivo analgesic, anti-inflammatory and in vivo acute toxicity evaluation. The structures of the acquired compounds were deduced through modern spectroscopic techniques including HR-ESI-MS, 13C-, and 1H NMR. Amongst the series, compounds 7, 9, and 10 attributed potent activities with 93.89, 92.50, and 90.47% decreased edema, respectively compared to flurbiprofen (90.01%), however, compounds 11 and 15 exhibited significant activity of 90.00% decrease. Out of them, fourteen compounds (1-6, 8, 12-14, and 16-19) displayed good activity in the range of 68.96-86.95%. In case of an analgesic study, all the derivatives significantly (p 0.001) increased the pain threshold time particularly compound 7 had the best analgesic effect (24 ± 2.08 s) in comparison with flurbiprofen (21.66 ± 2.02 s) using hot plate test. Similarly, in the acetic acid-induced writhing test, compound 7 determined a potent inhibitory effect (60.47 %) close to flurbiprofen (59.28%). All the synthesized derivatives were found safe up to the dose of 30 mg/kg, in acute toxicity study. On a molecular scale, the synthesized compounds were modeled through a ligand-based pharmacophore study and molecular docking to have insight into the different possible interactions leading to high inhibition levels against the COX-2 enzyme.

Development of Eudragit® Nanoparticles for Intranasal Drug Delivery: Preliminary Technological and Toxicological Evaluation

Intranasal administration has assumed in the last years an increasing value as an alternative strategy for the systemic adsorption of drugs, as an alternative to oral and parenteral routes thanks to the high vascularized nasal mucosa. Nevertheless, different drug features may restrict its absorption through the nasal mucosa with an insufficient diffusion to the systemic circulation. Several technological strategies are under investigation to improve drug absorption during nasal formulation design and production. The use of bioadhesive polymers can be considered a valid approach to pursue the aforementioned goal. Based on this consideration, Eudragit® Retard RS100 and RL100 resins were selected as positively charged copolymers to prepare polymeric NPs with potential mucoadhesive properties suitable for intranasal application. NPs were produced by the Quasi-emulsion Solvent Evaporation (QESD) method and loaded with diclofenac acid (DIC) or its epolamine salt (DIEP). Preliminary investigations were performed to obtain the optimized blank formulation and drugs loaded NPs evaluating different parameters that can affect particles size and polydispersity. The optimized formulations unloaded and loaded with DIC and DIEP were further evaluated for their thermotropic behavior by differential scanning calorimetry. Mucoadhesive evaluation was assessed by measuring variation in zeta potential and by turbidimetric assay after incubation of particles with mucin in simulated nasal fluid (SNF) at 37 °C at different time points (0, 1 and 24 h) compared to the pure suspensions. Stability of DIC and DIEP loaded NPs was also evaluated in SNF to predict potential aggregation phenomena after nasal administration. Finally, in vivo experiments showed absence of toxicity on the nasal mucosa of mice.

Effect of topical non-steroidal anti-inflammatory drugs on healing times and complications in dogs with spontaneous chronic corneal epithelial defects

BACKGROUND

Little is published regarding topical NSAID effect on corneal healing in dogs. This retrospective cohort study aimed to compare healing times and complications in dogs with spontaneous chronic corneal epithelial defects (SCCED) treated with and without topical non-steroidal anti-inflammatory drugs (NSAID).

METHODS

Medical records of 66 dogs (71 eyes) diagnosed with SCCED between 2008 and 2019 were included. Eyes were divided into: (1) those receiving topical NSAIDs (n = 33) versus (2) those not receiving topical NSAID (n = 38). Follow-up until healed, such as comfortable eye, negative fluorescein stain was required. Use of topical or systemic anti-inflammatories outside of NSAID or presence of ocular disorders or systemic endocrinopathies that may contribute to delayed healing resulted in study exclusion.

RESULTS

Healing times were significantly longer in eyes that received topical NSAID (p = 0.008), however, the use of more topical medications for treatment was also associated with longer healing times (p = 0.001). The majority of eyes in the NSAID group received multiple medications, compared to the non-NSAID group, so it was not possible to separate the effects of NSAID from a number of medications. Complications occurred in three eyes of three dogs within the NSAID group.

CONCLUSIONS

In these canine SCCED eyes, the use of more topical medications, including NSAID, was associated with significantly delayed healing time.

Use of topical bromfenac for treating ocular pain and inflammation beyond cataract surgery: a review of published studies

Topical ophthalmic nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat postoperative inflammation and pain following cataract surgery and for treatment and prophylaxis of pseudophakic cystoid macular edema (CME). Bromfenac is a brominated NSAID with strong in vitro anti-inflammatory potency. Like other ophthalmic NSAIDs, bromfenac is often used outside of the cataract surgery setting. This paper provides an overview of bromfenac’s preclinical ocular pharmacology and pharmacokinetics, followed by a review of 23 published clinical studies in which various marketed bromfenac formulations were used for conditions other than cataract surgery or pseudophakic CME. These include: post-refractive eye surgery; macular edema associated with diabetes, uveitis, or retinal vein occlusion; inflammation associated with age-related macular degeneration; pain related to intravitreal injections; and other ocular anterior segment and surface disorders with an inflammatory component. The published evidence reviewed supports the safety and effectiveness of bromfenac in these additional ophthalmic indications. Bromfenac was well tolerated when given alone or in combination with intravitreal anti-vascular endothelial growth factor agents, topical corticosteroids, or topical mast-cell stabilizers. The most common adverse event reported was ocular irritation. No serious adverse events (ie, corneal epithelial disorders) were reported, although the majority of studies did not systematically evaluate potential side effects. Corneal complications, such as melts reported with diclofenac and ketorolac, were not observed with bromfenac in the studies. In summary, published study data support the clinical utility of bromfenac in various ocular disorders beyond post-cataract surgery. Additional studies are warranted to further define the potential role of bromfenac ophthalmic solution in clinical practice.

Efficacy and perioperative timing of bromfenac in the management of ocular discomfort after femtosecond laser-assisted laser in situ keratomileusis

PURPOSE

To evaluate the safety, efficacy, and appropriate perioperative timing of the use of topical bromfenac ophthalmic solution 0.07% after femtosecond laser-assisted laser in situ keratomileusis (LASIK).

SETTING

Keil LASIK Vision Center, Grand Rapids, Michigan, USA.

DESIGN

Prospective case series.

METHODS

Ocular discomfort was assessed 1, 2, and 5 hours postoperatively and the following morning using the Ocular Comfort Grading Assessment in patients treated with topical bromfenac 0.07% or artificial tears just before, just after, or before and after femtosecond laser-assisted LASIK. Visual outcomes and complications were noted up to 24 hours.

RESULTS

The study enrolled 64 patients (120 eyes). Patients who were treated with bromfenac 0.07% just before or before and after femtosecond laser-assisted LASIK showed the greatest statistically significant decrease in several discomfort scores within the first few hours in comparison with the control group. Two hours after surgery, the majority of patients who were treated before and after LASIK were sleeping comfortably. There were no significant differences in visual acuity; 1 day postoperatively, the uncorrected distance visual acuity was 20/20 in 106 eyes (89%) and 20/25 or better in 116 eyes (97%). At 3 months, all patients had binocular distance visual acuity of 20/20 or better and 86% of patients had 20/15 or better.

CONCLUSION

Ocular discomfort after femtosecond laser-assisted LASIK was reduced with a single dose of topical bromfenac 0.07% given immediately before surgery or given just before and after surgery and was typically minimal in all groups the morning after surgery.

Efficacy and safety of pain relief medications after photorefractive keratectomy: review of prospective randomized trials

The objective of this review was to provide a comprehensive overview and comparison of results from all prospective randomized trials published to date of medications used to treat pain after photorefrative keratectomy (PRK). A PubMed database search revealed 23 prospective and randomized studies. They included the following classes of medications: nonsteroidal antiimflammatory drugs (NSAIDs), anesthetics, opiates, acetaminophen, gabapentin, and pregabalin. The studies found that although the efficacy of drugs tended to be similar, tetracaine 1% and nepafenac 0.1% tended to have the most analgesic effect. Delayed corneal reepithelialization was a common side effect of both topical anesthetics and topical NSAIDs. Tetracaine 1% resulted in the most significant delay in reepithelialization when tested against placebo control compared with other topical medications tested against placebo. Concomitant use of topical NSAIDs and topical anesthetics, especially tetracaine, may have to be avoided to minimize the risk for delayed corneal healing.

FINANCIAL DISCLOSURE

Neither author has a financial or proprietary interest in any material or method mentioned.

Time-resolved spectroscopic characterization of a novel photodecarboxylation reaction mediated by homolysis of a carbon α-bond in flurbiprofen

Flurbiprofen (Fp), a nonsteroidal anti-inflammatory drug (NSAID) currently in use for arthritis pain relief and in clinical trials for metastatic prostate cancer, can induce photosensitization and phototoxicity upon exposure to sunlight. The mechanisms responsible for Fp phototoxicity are poorly understood and deserve investigation. In this study, the photodecarboxylation reaction of Fp, which has been assumed to underpin its photoinduced side effects, was explored by femtosecond transient absorption (fs-TA), nanosecond transient absorption (ns-TA), and nanosecond time-resolved resonance Raman (ns-TR(3)) spectroscopic techniques in pure acetonitrile (MeCN) solvent. Density functional theory (DFT) calculations were also performed to facilitate the assignments of transient species. The resonance Raman and DFT calculation results reveal that the neutral form of Fp was the predominant species present in MeCN. Analysis of the ultraviolet/visible absorption spectrum and results from TD-DFT calculations indicate that the second excited singlet (S2) can be excited by 266 nm light. Due to its intrinsic instability, S2 rapidly underwent internal conversion (IC) to decay to the lowest lying excited singlet (S1), which was observed in the fs-TA spectra at very early delay times. Intriguingly, three distinct pathways for S1 decay seem to coexist. Specifically, other than fluorescence emission back to the ground state and transformation to the lowest triplet state T1 through intersystem crossing (ISC), the homolysis of the carbon α-bond decarboxylation reaction proceeded simultaneously to give rise to two radical species, one being carboxyl and another being the residual, denoted as FpR. The coexistence of the triplet Fp (T1) and FpR species was verified by means of TR(3) spectra along with ns-TA spectra. As a consequence of its apparent high reactivity, the FpR intermediate was observed to undergo oxidation under oxygen-saturated conditions to yield another radical species, denoted as FOR, which subsequently underwent intramolecular hydrogen transfer (IHT) and dehydroxylation (DHO) to form a final product, which could react with the carboxyl from the decarboxylation reaction to generate a minor final product. TD-DFT and transient state (TS) calculations for predicting the absorption bands and activation energies of the transient species produced in the photodecarboxylation reaction have provided valuable mechanistic insights for the assignment of the intermediate species observed in the time-resolved spectroscopy experiments reported here. The results of the time-resolved spectroscopy experiments and DFT calculations were used to elucidate the reaction mechanisms and intermediates involved in the photochemistry of Fp.

Effects of nonsteroidal ophthalmic drops on epithelial healing and pain in patients undergoing bilateral photorefractive keratectomy (PRK)

The present study, which was designed as a prospective, double-masked, randomized, controlled, single-site study, was conducted to compare the effects of 3 approved ophthalmic nonsteroidal anti-inflammatory drugs-nepafenac ophthalmic suspension 0.1% (Nevanac; Alcon Laboratories, Inc., Fort Worth, Tex), ketorolac tromethamine ophthalmic solution 0.4% (Acular LS; Allergan, Irvine, Calif), and bromfenac 0.09% (Xibromtrade mark; ISTA Pharmaceuticals, Irvine, Calif)-on corneal reepithelialization and postoperative pain control in patients undergoing photorefractive keratectomy. In addition to nonsteroidal anti-inflammatory drugs, each patient received an antibiotic-moxifloxacin hydrochloride ophthalmic solution 0.5% (nepafenac group) or gatifloxacin ophthalmic solution 0.3% (ketorolac and bromfenac groups). All treatments were administered 3 times daily beginning 1 d preoperatively and continuing for 1 wk postoperatively; prednisolone acetate 1.0% was administered concurrently 4 times daily. Bandage contact lenses were replaced at each postoperative visit for corneal staining and epithelial defect grading. Self-evaluation of pain relief was recorded on postoperative days 1 and 3 with the use of a visual analog scale. A total of 29 patients (58 eyes) were enrolled and underwent bilateral custom photorefractive keratectomy. Mean time to reepithelialization was 5.50+/-1.59 d for the nepafenac 0.1% group, 5.62+/-1.23 d for the ketorolac 0.4% group, and 7.25+/-2.53 d for the bromfenac 0.09% group. A significant difference was detected between nepafenac 0.1% and bromfenac 0.09% and between ketorolac 0.4% and bromfenac 0.09% (P<.05). Significant reductions in pain scores were observed with nepafenac 0.1% on day 1 (-1.13) and day 3 (-1.32), ketorolac 0.4% on day 3 (-0.88), and bromfenac 0.09% on day 3 (-0.83). No adverse events were reported. Eyes treated with nepafenac 0.1% or ketorolac 0.4% achieved complete reepithelialization significantly faster than those treated with bromfenac 0.09%. Daily contact lens removal and application of fluorescein may have delayed reepithelialization in the overall population; however, the effect would have been the same in all 3 groups. Pain relief with nepafenac 0.1% was achieved sooner than with ketorolac 0.4% or bromfenac 0.09%.

Double-masked study of the effects of nepafenac 0.1% and ketorolac 0.4% on corneal epithelial wound healing and pain after photorefractive keratectomy

Two NSAIDs--nepafenac 0.1% and ketorolac tromethamine 0.4%-were compared in terms of their effects on corneal reepithelialization and pain after photorefractive keratectomy (PRK) in a randomized, double-masked, contralateral eye, multicenter study. A total of 40 healthy adult patients who were undergoing sequential bilateral PRK received nepafenac 0.1% and ketorolac 0.4% in contralateral eyes, 1 drop 3 times daily for 3 d after bandage contact lens insertion. Patients were assessed on postoperative days 1, 3, 4, 5, and 7. At each visit, patients provided a general rating of pain. Each patient also assessed the sensation of each eyedrop following instillation (after-drop pain, irritation, burning/stinging, and overall comfort). Starting on day 3, epithelial defect size was assessed. Mean epithelial defect size was similar between treatments at each postoperative visit (P>.05). The average time-to-healing was 4.18 d for nepafenac 0.1% and 4.00 d for ketorolac 0.4% (P=.3134). No statistical difference was observed between nepafenac 0.1% and ketorolac 0.4% in mean postoperative pain scores (P>.05). On day 3, the nepafenac 0.1% group had significantly lower mean sensation scores than did the ketorolac 0.4% group for after-drop pain (P=.0090), irritation (P=.0007), and burning/ stinging (P=.0003). Mean overall comfort score was also significantly better for nepafenac 0.1% on day 3 (7.43 vs 6.41; P<.0001). Nepafenac 0.1% and ketorolac 0.4% provide postoperative pain relief after PRK surgery without associated adverse effects on corneal epithelial healing. Nepafenac 0.1% treatment may offer greater comfort upon instillation in patients who have undergone PRK.

Intérêt d’une nouvelle formulation de diclofénac sans conservateur pour la surface oculaire

AIM

To compare the ocular tolerance of nonpreserved diclofenac versus thiomersal-preserved diclofenac in healthy volunteers.

MATERIALS AND METHODS

Forty healthy volunteers instilled Dicloabak in the randomised eye and thiomersal-preserved diclofenac in the other eye, according to a strictly identical dosing regimen, for 28 days. Each volunteer thus served as his or her own control. The dose regimen was five drops/day for 7 days followed by three drops/day for 20 days. Ocular tolerance was assessed by the discomfort upon instillation (measured on a visual analogue scale [VAS]), subjective ocular symptoms following instillation (irritation/burning/stinging, eye dryness and foreign body sensation) and finally by an objective examination of the ocular surface. These criteria were evaluated on days 0, 14, 21 and 28.

RESULTS

The subjective ocular symptoms following instillation were significantly lower in the nonpreserved group at Day 7 and nearly significantly lower until the end of the study. The biomicroscopy exam confirmed that there was better tolerance without thiomersal. There was less follicular-papillary conjunctivitis and a significantly better lissamine green score in the Dicloabak group.

CONCLUSION

The results of this study demonstrate that the nonpreserved formulation of diclofenac is better tolerated by the ocular surface and thus constitutes a therapeutic benefit.

Characterisation of the lowest singlet and triplet excited states of S-flurbiprofen

The photophysical properties of S-flurbiprofen [S-2-fluoro-alpha-methyl-4-biphenylacetic acid], a nonsteroidal anti-inflammatory drug, have been examined using steady-state and time-resolved spectroscopic techniques. The energy of its first singlet excited state is 99 kcal mol(-1). The fluorescence quantum yields and lifetimes (at 300 nm) have been determined in acetonitrile, methanol, hexane and PBS; they are in the range 0.15<phi(F)< 0.33 and 0.7<tau(F)<2.0 ns. The intersystem crossing quantum yields are between 0.45 and 0.71; the lambda(max) of the T-T absorption is 360 nm, and the triplets live from 15 to 106 micros. Steady state photolysis in aqueous medium leads to S-2-hydroxy-alpha-methyl-4-biphenylacetic acid via photonucleophilic aromatic substitution, in addition to the photodecarboxylation products observed in organic solvents.

Ocular drug permeation following experimental excimer laser treatment on the isolated pig eye

Excimer laser photorefractive keratectomy (PRK) is a well-established procedure which is frequently applied to correct myopia. Since structural alterations of the corneal epithelium occur after the treatment, a different drug permeation can be assumed. To investigate the effects of PRK on drug permeation, excimer laser ablations with varying depths were performed on isolated pig eyes. The permeation of lipophilic (diclofenac-sodium; D-Na) and hydrophilic (pilocarpine-hydrochloride; P-HCl model drugs were studied in vitro. Under these experimental conditions, P-HCl demonstrated a significant (p < 0.05) enhancement of permeation in relation to the ablation depth. In contrast, corneal epithelial thickness scarcely influenced the permeation rate of D-Na. Not until removing the entire epithelium did a significantly increased permeability occur, when compared to untreated cornea. These results suggest that PRK may significantly reduce the corneal barrier function and alter pharmacokinetics of topical medication.

Saxitoxin: an anesthetic of the deepithelialized rabbit cornea

PURPOSE

The aim of the current study was to define the efficacy of saxitoxin as a corneal anesthetic in rabbits after mechanical corneal abrasion and photorefractive keratectomy (PRK).

METHODS

Twelve Dutch belted rabbits were given a single 1.2-microg dose of saxitoxin or vehicle after mechanical abrasion of the cornea. Corneal sensation was evaluated hourly for 6 hours. A second group of 12 Dutch belted rabbits was given a 1.2-microg dose of saxitoxin or vehicle every 5 hours for 30 hours after PRK. Corneal sensation was evaluated after 5, 10, 15, 20, 25, and 30 hours. Pachometry was performed before PRK and again after the epithelial defects had healed. The rate of epithelial defect closure was assessed by measuring the epithelial defect size 25, 42, 65, 88, and 113 hours after PRK.

RESULTS

A dose of 1.2 microg of saxitoxin given every 5 hours produced continuous corneal anesthesia after PRK. There was no difference in the rate of wound healing between eyes treated with saxitoxin and vehicle. There was no difference in the degree of wound healing, as measured by pachometry, between eyes treated with saxitoxin and vehicle. There were no apparent ocular or systemic toxic effects from saxitoxin administration.

CONCLUSION

At a dose of 1.2 microg, saxitoxin is a safe, effective, long-acting corneal anesthetic in rabbits after PRK.

A randomized, double-masked, clinical study of the efficacy of four nonsteroidal anti-inflammatory drugs in pain control after excimer laser photorefractive keratectomy

OBJECTIVE

This study assessed the efficacy of 4 nonsteroidal anti-inflammatory drugs (NSAIDs) after excimer laser photorefractive keratectomy (PRK).

BACKGROUND

Inadequate control of pain after PRK surgery can be a severe source of distress to patients and can interfere with their willingness to undergo a second PRK procedure.

METHODS

This randomized, double-masked, placebo-controlled clinical study was conducted in 125 patients. Four NSAIDs (diclofenac, flurbiprofen, ketorolac, and indomethacin) were tested against a placebo group (artificial tears). Pain levels after PRK were quantified using Present Pain Intensity (PPI) and Pain Rating Indices based on rank values (PRI[R]) scores, both of which were calculated using patient responses to a modified McGill Pain Questionnaire. The PRI(R) consisted of 4 subscales-sensory (S), affective (A), evaluative (E), and miscellaneous (M)-as well as a total score (T).

RESULTS

Three hours after PRK, no differences in PPI scores were found between the ketorolac, diclofenac, and indomethacin groups, whereas placebo was significantly less effective than the NSAIDs. Patients who received flurbiprofen reported PPI scores that were significantly lower (P < 0.001) than those of patients who received diclofenac and indomethacin, but PPI scores in the flurbiprofen and the ketorolac groups did not differ significantly. Twenty-four hours after surgery, patients treated with flurbiprofen, ketorolac, and diclofenac reported the lowest PPI scores compared with those treated with indomethacin and placebo (P < 0.001). Moreover, flurbiprofen-treated patients also had the lowest PRI(R)T scores (P < 0.001). When the pain rating index was examined by subclass, a significantly lower PRI(R)S score was detected in the flurbiprofen group at 24 hours (P < 0.001). The PRI(R)A score was significantly higher in the placebo and indomethacin groups compared with the other groups (P < 0.001). At the 48- and 72-hour time points, flurbiprofen-treated patients again reported significantly lower PPI and PRI(R)T scores (P < 0.001 for both) in pair-wise comparisons with the other treatment groups. The number of patients who self-administered additional oral analgesics did not differ significantly between the groups. However, the mean number of analgesic tablets used was significantly higher in the placebo group than in any NSAID group (P < 0.001). The ketorolac group had the largest number of patients complaining of itching (P < 0.043). No other subjective symptoms were significantly different across groups. Finally, all NSAIDs, except flurbiprofen, prolonged the mean reepithelialization period slightly (P < 0.001).

CONCLUSIONS

Flurbiprofen appeared to be the most effective NSAID for the treatment of pain, even at 24 hours after surgery when pain was at a maximum.