Effects of sodium naproxen eye drops on rabbit ocular inflammation induced by sodium arachidonate

Assessment of Efficacy and Safety Using PPAR-γ Agonist-Loaded Nanocarriers for Inflammatory Eye Diseases

Drug-loaded nanocarriers (NCs) are new systems that can greatly improve the delivery and targeting of drugs to specific tissues and organs. In our work, a PPAR-γ agonist loaded into polymeric NCs was prepared, stabilized by spray-drying, and tested in vitro, ex vivo, and in vivo (animal models) to provide a safe formulation for optical anti-inflammatory treatments. The NCs were shown to be well tolerated, and no signs of irritancy or alterations of the eye properties were detected by the in vitro HET-CAM test and in vivo Draize test. Furthermore, no signs of cytotoxicity were found in the NC formulations on retinoblastoma cells (Y-79) analyzed using the alamarBlue assay, and the transmittance experiments evidenced good corneal transparency with the formulations tested. The ocular anti-inflammatory study confirmed the significant prevention efficacy using the NCs, and these systems did not affect the corneal tissue structure. Moreover, the animal corneal structure treated with the NCs was analyzed using X-ray diffraction using synchrotron light. Small-angle X-ray scattering (SAXS) analysis did not show a significant difference in corneal collagen interfibrillar spacing after the treatment with freshly prepared NCs or NCs after the drying process compared to the corresponding negative control when inflammation was induced. Considering these results, the PPAR-γ agonist NCs could be a safe and effective alternative for the treatment of inflammatory ocular processes.

A Second Generation Prostanoid Receptor Antagonist Acting at Multiple Receptor Subtypes

It has previously been reported that a prototypical compound (AGN 211377), which blocks pro-inflammatory prostanoid receptors (DP₁, DP₂, EP₁, EP_4, FP, TP) and leaves open IP and EP₂ receptors so that their anti-inflammatory properties could be exerted, produced superior inhibitory effects on cytokine release from human macrophages compared to cyclooxygenase (COX) inhibitors. This favorable activity profile translated into animal studies, with AGN 211377 exceeding the level of inhibition afforded by COX inhibition. AGN 211377 was not, however, a practical drug candidate, having poor bioavailability and cost of goods concerns. Compound 1 (designated AGN 225660) represents a second-generation compound with an entirely different "druggable" core structure. Such a dramatic change in chemical scaffold created uncertainty with respect to matching the effects of AGN 211377. AGN 225660 inhibited RANTES, IL-8, and MCP-1 secretion by at least 50%, from TNFα activated human macrophages. Although AGN 225660 reduced TNFα-evoked MCP-1 release from human monocyte-derived macrophages, it increased LPS-induced MCP-1 secretion (up to 2-fold) from human monocyte-derived dendritic cells. However, AGN 225660 inhibited the release of IL12p 70 and IL-23 from human monocyte-derived dendritic cells stimulated by LPS by more than 70%. This effect of AGN 225660 was reproduced in part by the prototype compound AGN 211377 and a combination of selective DP₁, EP₁, EP₄, FP, and TP antagonists. These findings suggest important effects on T cell skewing and disease modification by this class of therapeutic agents. AGN 225660 exhibited good ocular bioavailability and was active in reducing ocular inflammation associated with phacoemulsification surgery, LPS, and arachidonic acid induced uveitis.

Topical Nonsteroidal Anti-Inflammatory Drugs in Uncomplicated Cataract Surgery: Effect of Sodium Naproxen

Purpose

To investigate whether topical nonsteroidal anti inflammatory drugs (NSAIDs) are useful, in the absence of concomitant corticosteroid therapy, in limiting postoperative inflammation after uncomplicated cataract surgery.

Methods

A total of 328 patients were enrolled in a prospective, randomized, double-masked, parallel-group, active-controlled study. Anterior chamber inflammation (ACI) was evaluated as the primary efficacy parameter. Only patients with moderate inflammation (ACI score of ≤4) the day after surgery were randomized and treated with NSAIDs. A novel topical formulation containing 0.2% sodium naproxen was compared with 0.1% diclofenac. Both were administered three times a day for 14 consecutive days. Ocular inflammation was measured after 7 and 14 days by using slit-lamp biomicroscopy. Safety parameters were also evaluated at the same time.

Results

Both treatments were equally effective in controlling postsurgical inflammation. No statistically significant differences between treatment groups were observed for the safety variables. No serious adverse events (AEs) occurred during the course of the study. The most frequent AE reported with naproxen was eye redness.

Conclusions

NSAIDs can effectively be used without concurrent administration of corticosteroids to control postoperative inflammation after uncomplicated cataract surgery. In addition, naproxen ophthalmic solution may be considered a suitable alternative to the currently available NSAIDs.

In vitro, ex vivo and in vivo characterization of PLGA nanoparticles loading pranoprofen for ocular administration

Pranoprofen (PF) is a NSAID considered as a safe anti-inflammatory treatment for strabismus and/or cataract surgery. The drug has been formulated in poly (lactic/glycolic) acid (PLGA) nanoparticles (PF-F1NPs with cPF 1.5mg/mL, PF-F2NPs with cPF 1mg/mL) produced by solvent displacement technique and tested the in vitro cytotoxicity, ex vivo corneal permeation, in vivo ocular tolerance and in vivo anti-inflammatory efficacy of PF-F1NPs, PF-F2NPs, in comparison to eye drops conventional dosage form (Oftalar(®), PF 1mg/mL) and free drug solution (PF dissolved in PBS, 1.5mg/mL). The mean particle size of both formulations was around 350nm, with polydispersity index below 0.1, and a net negative charge of -7.41mV and -8.5mV for PF-F1NPs and PF-F2NPs, respectively. Y-79 human retinoblastoma cell line was used to evaluate the cytotoxicity of PF-F1NPs and PF-F2NPs, which were compared to blank NPs and free drug solution (PF dissolved in PBS, 1.5mg/mL). Concentrations up to 75μg/mL exhibited no toxicity to Y-79 cells, whereas at 150μg/mL a decrease of about 80% on the cell viability was observed after exposing the cells to PF-F1NPs. When treating the Y-79 cells with concentrations of PF-F2NPs between 1μg/mL to 100μg/mL, the cell viability was similar to control values after 24h and 48h of exposure. An ex vivo corneal permeation study was carried out in New Zealand rabbits. A very similar profile has been observed for the permeation of PF through the cornea when administered as eye drops and as free drug solution, which was kept much lower in comparison to PF-NPs formulations. The permeated amount of PF from the PF-F1NPs was slightly smaller than from PF-F2NPs, attributed to the increase of viscosity of the formulations with the increase of cPVA concentration. New Zealand white rabbits were also used to evaluate the irritancy of PF-F1NPs and PF-F2NPs, which demonstrated to be well-tolerated to the eye (i.e. the mean total score (MTS) was 0). PF-F2NPs exhibited the highest QP (amounts of PF permeated in the cornea) and significantly reduced the ocular edema compared to the tested formulations. The QR (amounts of PF retained in the cornea) of the PF-F1NPs was greater than that obtained for PF-F2NPs.

Biopharmaceutical profile of pranoprofen-loaded PLGA nanoparticles containing hydrogels for ocular administration

Two optimized pranoprofen-loaded poly-l-lactic-co glycolic acid (PLGA) nanoparticles (PF-F1NPs; PF-F2NPs) have been developed and further dispersed into hydrogels for the production of semi-solid formulations intended for ocular administration. The optimized PF-NP suspensions were dispersed in freshly prepared carbomer hydrogels (HG_PF-F1NPs and HG_PF-F2NPs) or in hydrogels containing 1% azone (HG_PF-F1NPs-Azone and HG_PF-F2NPs-Azone) in order to improve the ocular biopharmaceutical profile of the selected non-steroidal anti-inflammatory drug (NSAID), by prolonging the contact of the pranoprofen with the eye, increasing the drug retention in the organ and enhancing its anti-inflammatory and analgesic efficiency. Carbomer 934 has been selected as gel-forming polymer. The hydrogel formulations with or without azone showed a non-Newtonian behavior and adequate physicochemical properties for ocular instillation. The release study of pranoprofen from the semi-solid formulations exhibited a sustained release behavior. The results obtained from ex vivo corneal permeation and in vivo anti-inflammatory efficacy studies suggest that the ocular application of the hydrogels containing azone was more effective over the azone-free formulations in the treatment of edema on the ocular surface. No signs of ocular irritancy have been detected for the produced hydrogels.

Conjugation of cell-penetrating peptides with poly(lactic-co-glycolic acid)-polyethylene glycol nanoparticles improves ocular drug delivery

In this work, a peptide for ocular delivery (POD) and human immunodeficiency virus transactivator were conjugated with biodegradable poly(lactic-co-glycolic acid) (PGLA)-polyethylene glycol (PEG)-nanoparticles (NPs) in an attempt to improve ocular drug bioavailability. The NPs were prepared by the solvent displacement method following two different pathways. One involved preparation of PLGA NPs followed by PEG and peptide conjugation (PLGA-NPs-PEG-peptide); the other involved self-assembly of PLGA-PEG and the PLGA-PEG-peptide copolymer followed by NP formulation. The conjugation of the PEG and the peptide was confirmed by a colorimetric test and proton nuclear magnetic resonance spectroscopy. Flurbiprofen was used as an example of an anti-inflammatory drug. The physicochemical properties of the resulting NPs (morphology, in vitro release, cell viability, and ocular tolerance) were studied. In vivo anti-inflammatory efficacy was assessed in rabbit eyes after topical instillation of sodium arachidonate. Of the formulations developed, the PLGA-PEG-POD NPs were the smaller particles and exhibited greater entrapment efficiency and more sustained release. The positive charge on the surface of these NPs, due to the conjugation with the positively charged peptide, facilitated penetration into the corneal epithelium, resulting in more effective prevention of ocular inflammation. The in vitro toxicity of the NPs developed was very low; no ocular irritation in vitro (hen's egg test-chorioallantoic membrane assay) or in vivo (Draize test) was detected. Taken together, these data demonstrate that PLGA-PEG-POD NPs are promising vehicles for ocular drug delivery.

Topical ocular delivery of NSAIDs

In ocular tissue, arachidonic acid is metabolized by cyclooxygenase to prostaglandins which are the most important lipid derived mediators of inflammation. Presently nonsteroidal anti-inflammatory drugs (NSAIDs) which are cyclooxygenase (COX) inhibitors are being used for the treatment of inflammatory disorders. NSAIDs used in ophthalmology, topically, are salicylic-, indole acetic-, aryl acetic-, aryl propionic- and enolic acid derivatives. NSAIDs are weak acids with pKa mostly between 3.5 and 4.5, and are poorly soluble in water. Aqueous ophthalmic solutions of NSAIDs have been made using sodium, potassium, tromethamine and lysine salts or complexing with cyclodextrins/solubilizer. Ocular penetration of NSAID demands an acidic ophthalmic solution where cyclodextrin could prevent precipitation of drug and minimize its ocular irritation potential. The incompatibility of NSAID with benzalkonium chloride is avoided by using polysorbate 80, cyclodextrins or tromethamine. Lysine salts and alpha-tocopheryl polyethylene glycol succinate disrupt corneal integrity, and their use requires caution. Thus a nonirritating ophthalmic solution of NSAID could be formulated by dissolving an appropriate water-soluble salt, in the presence of cyclodextrin or tromethamine (if needed) in mildly acidified purified water (if stability permits) with or without benzalkonium chloride and polyvinyl alcohol. Amide prodrugs met with mixed success due to incomplete intraocular hydrolysis. Suspension and ocular inserts appear irritating to the inflamed eye. Oil drop may be a suitable option for insoluble drugs and ointment may be used for sustained effect. Recent studies showed that the use of colloidal nanoparticle formulations and the potent COX 2 inhibitor bromfenac may enhance NSAID efficacy in eye preparations.

Chirality in ocular agents

PURPOSE OF REVIEW

To review the role of chirality in current ocular pharmacology. The importance of stereo-isomeric purity has frequently been emphasized in recent years. Development of chirally pure medications can lead to improved efficacy and side-effect profiles. Practitioners prescribing ocular agents may benefit from understanding the effects of chirality in their evaluation of old and new medications.

RECENT FINDINGS

Chirality can affect multiple classes of ocular agents. Although the ways in which stereo-isomers influence the properties of a drug differ, this review illustrates the benefit of knowledge of individual isomers' effects in clinical decision making. The variety of possible effects stereo-isomers produce further underlines the importance of purification and in-depth analysis of chiral compounds.

SUMMARY

Many important agents exist as a mixture of two different stereoisomers. Both isomers may produce a pharmacological effect; however, these effects may be different from one another and one isomer may even give a result opposite from the desired pharmacological effect. Here we examine published findings on ocular medications relating to their chiral nature and summarize the possible ways chirality affects the activity of a few ocular agents. Many more ocular medications have not been investigated to ascertain their chiral properties. This review adds to the recent emphasis on investigating stereo-isomers for individual selectivity of beneficial and adverse profiles.

Flurbiprofen loaded biodegradable nanoparticles for ophtalmic administration

Poly(lactic/glycolic) acid nanoparticles incorporating flurbiprofen (FB) were prepared by the solvent displacement technique using poloxamer 188 as a stabilizer to improve the availability of the drug for the prevention of the inflammation caused by ocular surgery. A 2(3) + star design was applied to investigate the influence of several factors such as the pH of the aqueous phase, the initial concentration of the stabilizer, and the drug used to prepare the nanoparticles (NPs) on the physicochemical properties (particle size analysis, zeta potential, and drug loading efficiency) of the colloidal system. The best formulations were those prepared at pH 3.5 with a concentration of 1.5 mg/mL of FB and 10 or 20 mg/mL of poloxamer 188. These formulations showed an appropriate average size for ophthalmic administration (232.8 and 277.6 nm, respectively) and a good yield of entrapment efficiency (94.60% and 93.55%, respectively). The release behavior of FB from the developed NPs was complete and exhibited a biphasic pattern. Formulations did not show toxicity on ocular tissues. In vivo anti-inflammatory efficacy was assessed in the rabbit eye after topical instillation of sodium arachidonate (SA). A higher decrease of the SA-induced inflammation was obtained for the NP formulations.

Engineered microcrystals for direct surface modification with layer-by-layer technique for optimized dissolution

This investigation relates to a two-step formulation development technique-synthesis of sterically stabilized drug microcrystals followed by direct surface modification by sequential electrostatic adsorption. Stable microcrystals of naproxen were produced by pH-induced reprecipitation in presence of a stabilizer. Sequential layer growth was achieved by the layer-by-layer assembly of biocompatible polyelectrolytes (PEs) and was registered using microelectrophoresis. The coated colloids were characterized using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). The in vitro controlled release pattern of the drug through the PE diffusion barrier was studied using a diffusion cell assembly at physiological pH of 7.4, both before and after freeze-drying. Thermodynamically stable naproxen microcrystals were obtained by association and had a mean length of 15 microm and a zeta potential of -37.5 mV and were surface modified efficiently using biocompatible polysaccharide/protein-based PEs. Sufficient charge reversal with each layer was evident indicating layer growth with successive deposition cycles. The coating was complete and homogeneous as visualized under CLSM and SEM. The in vitro release study revealed that the stoichiometry of PEs in the complex coating and its molecular architecture played important roles in forming the diffusion barrier, which offered efficient control of the dissolution rate of drug core (up to 50% lower than bare crystal). The release profile fitted zero order release kinetics. This novel formulation technique enables administration of high concentrations of water-insoluble drugs in a stable, tissue compatible form, simultaneously affording sustained release.

Topical naproxen sodium for inhibition of miosis during cataract surgery. Prospective, randomized clinical trials

PURPOSE

To assess corneal penetration of naproxen sodium and its efficacy in maintaining intraoperative mydriasis during cataract surgery.

METHODS

Two double blind studies have been performed comparing the efficacy of naproxen ophthalmic solution to that of placebo or diclofenac in inhibiting pre-operative miosis. Study No. 1 was a placebo-controlled study and involved 194 patients undergoing extracapsular cataract extraction. Study No. 2 was an active-controlled study (vs diclofenac) concerning 214 patients undergoing phacoemulsification. In both studies treatment started the day before surgery. A balanced salt solution containing adrenaline was used in all patients. Pupil size was measured prior to the corneal section and at the end of surgery. An aqueous humor sample was taken immediately before corneal incision in a subset of 20 patients to measure naproxen aqueous concentration.

RESULTS

In both studies the pupillary diameter decreased during surgery within each treatment group in a statistically significant manner (P < 0.001). Naproxen was more effective than placebo (P < 0.01) and as effective as diclofenac in controlling pupil diameter regression during cataract. Mean concentration level of naproxen in the aqueous humor was 372.3 ng/ml.

CONCLUSIONS

Naproxen sodium ophthalmic solution penetrates the cornea and it is effective in maintaining intraoperative mydriasis.

Naproxen ophthalmic solution to manage inflammation after phacoemulsification

PURPOSE

To explore the efficacy and safety of 2 concentrations (0.1% and 0.2%) of sodium naproxen ophthalmic solution in controlling ocular inflammation in patients having phacoemulsification and intraocular lens implantation.

SETTING

Service d'Ophtalmologie La Pitie' and Centre Ophtalmologique, Paris, and Clinique Sourdille, Nantes, France; Department of Ophthalmology, University of Lausanne, Switzerland.

METHODS

One hundred one patients were randomly treated with naproxen 0.1%, naproxen 0.2%, or diclofenac 0.1% 3 times a day for 30 days starting the day before surgery. Postsurgical ocular inflammation was measured after 1, 10, and 30 days using the Kowa FC-1000 laser flare-cell meter and a conventional slitlamp biomicroscope. Safety parameters were evaluated at the same visits.

RESULTS

Naproxen 0.2% ophthalmic solution and diclofenac 0.01% were comparable in controlling postsurgical inflammation. The naproxen was well tolerated. No serious adverse events occurred during the study.

CONCLUSIONS

These preliminary results suggest that naproxen ophthalmic solution may be effectively and safely used to control inflammation after uneventful phacoemulsification. Because of the limited number of patients, larger studies are needed to confirm these results.

Pharmacological profile of oxaprozin eye drops

The effects of eye drops containing a propionic acid derivative (oxaprozin) at 0.1% concentration on ocular inflammation produced by sodium arachidonate in the rabbit's eye were evaluated. Furthermore, the aqueous bioavailability of the drug formulation in the uninflamed and inflamed eyes was evaluated. Oxaprozin eye drops significantly reduced the signs of ocular inflammation elicited by sodium arachidonate on conjunctiva and iris. Oxaprozin treatment significantly reduced the levels of polymorphonuclear leukocytes and protein concentration in aqueous samples obtained from the eyes treated with arachidonate. Present data suggest, for the first time, that oxaprozin may be employed topically to prevent ocular reactions where the arachidonic acid cascade is activated.

4-quinazolinones: synthesis and reduction of prostaglandin E2 production

We synthesized and evaluated the anti-inflammatory activity of a series of 4-quinazolinone derivatives. Two approaches were used to yield the title compounds. A first group of quinazolinone derivatives was obtained by the appropriate substituted anthranilates. A second group of quinazolinone compounds was prepared through the benzoxazin-4-ones intermediate. The pharmacological results reveal that the synthesized derivatives exhibit a significant anti-inflammatory effect in an experimental ocular inflammation model. In fact, all the tested compounds lowered the prostaglandin E2 (PGE2) production with respect to the control group (P < 0.05). The 3-cyclohexyl-6-chloro-quinazolin-4(3H)-one and 3-cyclohexyl-quinazolin-4(3H)-one derivatives were the most active compounds. These compounds significantly reduced PGE2 levels even more than the reference drug tolmetin and significantly lower protein concentration and polymorphonuclear leukocytes number compared to the control group (P < 0.05). Therefore, these compounds may be useful to prevent ocular inflammatory reactions.

Flurbiprofen, S(+), eyedrops: formulation, enantiomeric assay, shelf-life and pharmacology

Aphakic cystoid macula edema, occurring after cataract extraction is ascribed to trauma-induced production of intra-ocular prostaglandins. Sufficient experimental and clinical evidence supports the use of prostaglandin synthesis inhibitors to countervail this clinical condition. The active S(+)-enantiomer of flurbiprofen, a prostaglandin synthesis inhibitor, has been formulated into a stereoselective, ballast free eyedrop solution in a concentration of 0.015%. Analysis by capillary zone electrophoresis shows shelf-life stability up to four years at room temperature of this enantiomer. The inhibitory effect on the synthesis of prostaglandins as measured on a homogenate bovine iris/ciliary body, remained unaffected during a shelf-life period of three years.

Pharmacological evaluation of anti-inflammatory pyrrole-acetic acid derivative eye drops

The effects of mucoadhesive eye drops containing a pyrrole-acetic acid derivative (tolmetin) at 0.5% concentration on ocular inflammation produced by sodium arachidonate in the rabbit's eye were evaluated. Furthermore, the bioavailability of the mucoadhesive formulation in the aqueous humor against an aqueous-based solution was compared. Tolmetin eye drops significantly reduced the signs of ocular inflammation elicited by sodium arachidonate on conjunctiva and iris. Tolmetin treatment significantly reduced the levels of prostaglandin E2, polymorphonuclear leukocytes and protein concentration in aqueous samples obtained from the eyes treated with arachidonate. The de novo production of prostaglandin E2 by corneas obtained from rabbits sacrificed 2 hours after arachidonate instillation were significantly higher in samples taken from controls than in corneas obtained from the eyes treated with tolmetin eye drops. Furthermore, the drug treatment significantly reduced the rise in intraocular pressure arachidonate-induced. The mucoadhesive formulation showed a higher bioavailability in aqueous humor compared to the aqueous-based solution both in the uninflamed and in the inflamed rabbit eyes.

Effect of sodium naproxen on inflammatory response induced by anterior chamber paracentesis in the rabbit

This study evaluated the effect of sodium naproxen (a reversible competitive inhibitor of cyclo-oxygenase) and phenylephrine (a mydriatic alpha-adrenergic agent) eye drops in maintaining atropine mydriasis in the rabbit after paracentesis. Moreover, to assess the influence of these treatments on vascular and cellular inflammatory responses in the rabbit eye, several biochemical parameters were considered. Anterior chamber paracentesis significantly reduced atropine-induced mydriasis and a parallel elevation of proteins, polymorphonuclear leucocytes (PMNs), prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels in the secondary aqueous humour (obtained 120 min later) was observed. A significant increase in PMNs in the aqueous humour and a parallel increase in myeloperoxidase activity, a measure of PMN infiltration, in the iris-ciliary body were detected. Atropine-induced mydriasis was maintained in rabbits treated with either sodium naproxen or phenylephrine eye drops. However, only in the former group were the inflammatory parameters significantly reduced, with the exception of aqueous LTB4 levels. The inhibition of the protein influx in the aqueous humour and of the miosis produced by sodium naproxen can be related to the high drug levels in the aqueous humour that were effective in inhibiting the cyclo-oxygenase pathway of arachidonic acid metabolism, whereas the effects on PMN infiltration appear to be independent of significant release of the potent chemotactic agent LTB4, synthesized via the 5-lipoxygenase pathway.